bluuebunny/crossref_metadata_2025 huggingface dataset:
Influence of Calcination Temperature on Synthesis of Magnetite (Fe3O4) Nanoparticles by Sol-Gel Method
Authors: Worawong Apichaya , Jutarosaga Tula , Onreabroy Wandee
Published: June 2014

Magnetite (Fe3O4) nanoparticles were successfully synthesized by the sol-gel method from ferric nitrate-EG (EG=ethylene glycol) gel. The precursors were calcined in argon under an atmospheric pressure at the temperatures varied from 400°C to 500°C. The synthesized magnetic nanoparticles were characterized by X-ray diffractrometer (XRD), field emission scanning electron microscope (FE-SEM) and vibrating sample magnetometer (VSM). The XRD patterns of powder calcined temperature at 400๐C showed clearer Fe3O4 phase than those calcined at other temperatures. The particle size and morphology of magnetic nanoparticles were studied using FE-SEM. The FE-SEM images showed that the particle sizes varied from 30-108 nm. The particle sizes increased with the increase of calcination temperature. VSM measurements indicated that the Fe3O4 nanoparticles were soft ferrite with the maximum magnetization (Mm) and coercivity (Hc) of 35 emu/g and 17 Oe, respectively.
Analysis of Neutron Flux Measurement in Thai Research Reactor-1/Modification 1 Using the Monte Carlo Method
Authors: Sabaibang S. , Lekchaum S. , Tippayakul C.
Published: June 2014

This study adopts the Monte Carlo method to analyze the neutron flux measurement technique in Thai Research Reactor-1/Modification 1(TRR-1/M1) by performing simulations using MCNPX computer program. The neutron flux measurement technique being analyzed is called “gold foil activation technique”. The simulation model consists of gold foil located in the middle of in-core irradiation which is in the center of the reactor core. The variation in the calculated neutron flux is assessed by varying the gold foil thickness from approximately 500 – 800 μcm. It is found from the simulation that the calculated neutron flux can differ by 33 % when increasing the gold foil thickness by 60%. In addition, more detailed simulations to determine neutron flux distribution within the gold foil are performed to study and explain the variation in neutron flux calculated at different foil thicknesses. The simulation result shows that self-shielding effect has significant impact to the neutron flux distribution within the gold foil, and hence to the average neutron flux.
Synthesis and Characterization of BNKT/ZnO Ferroelectric Lead-Free Nanocomposites
Authors: Wichasilp C. , Inthong Suchittra , Maithong W. , Kruea-In N. , Kruea-In C.
Published: June 2014

In this research, the effects of ZnO nanoparticles additive on crystallization behavior, dielectric and ferroelectric properties of Bi0.5(Na0.81,K0.19)0.5TiO3 ceramics were investigated. The samples were synthesized by solid state reaction technique, where powders were calcined at 850 °C for 4 h and ceramics were sintered at 1100-1150 °C for 4 h. Phase formation was determined by X-ray diffraction technique (XRD). The X-ray diffraction analysis of the ceramics suggests that all samples exhibited a perovskite structure. The dielectric properties under room temperature and various temperatures were also determined. Dielectric measurement data showed that the additive influenced dielectric constant and dielectric loss. Furthermore, the hysteresis loop behaviors slightly changed with increasing the nanoparticles contents.
Physical and Gamma-Ray Shielding Properties of Strontium Borosilicate Glasses
Authors: Tuscharoen Suparat , Kaewkhao Jakrapong
Published: June 2014

Glasses composition of xSrO:(70–x)B2O3:30SiO2 when 25≤x≤50 mol% were prepared using the melt quenching technique and investigated the other properties of glasses. The density of the glasses was measured using Archimedes’ principle; the molar volume of the glasses has been derived from density measurements data. The hardness of glasses sample was measured by using the Vickers hardness. Mass attenuation coefficients have been determined experimentally for the glass system at photon energy 662 keV, the results compared with theoretical calculations from WinXCom computer software. The reported data should be useful for decision chosen of these glasses in radiation shielding.
Effects of Annealing Treatment on WO3 Thin Films Prepared by DC Reactive Magnetron Sputtering
Authors: Srichaiyaperk Thanat , Aiempanakit Kamon , Horprathum Mati , Eiamchai Pitak , Chananonnawathorn Chanunthorn , Limwichean Saksorn , Chindaudom Pongpan
Published: June 2014

Tungsten trioxide (WO3) thin films were prepared by a DC reactive magnetron sputtering technique. The thin film fabrication process used tungsten (99.995%) as the sputtering target, the mixture of argon and oxygen as sputtering and reactive gases, and silicon (100) and glass slides as the substrates. The effects of annealing temperature in the range of 200-400°C on physical and optical properties of the WO3 thin films were investigated. The nanostructures and morphologies of these films were characterized by grazing-incident X-ray diffraction (GIXRD) and field-emission scanning electron microscopy (FE-SEM). The optical properties were analyzed by variable-angle spectroscopic ellipsometry (VASE) and spectrophotometer. From the XRD results, the as-deposited and annealed WO3 thin films up to 300°C were all amorphous. Only the WO3 thin film annealed at 400°C exhibited a polycrystalline monoclinic phase. The FE-SEM cross-sections and surface topologies demonstrated nearly identical thin-film thickness and physical grain sizes. The SE analyses showed that the thin films were all homogeneous dense layers with additional surface roughness. With the annealing treatment, the thin film thickness was slightly decreased. The SE physical model was best optimized with the Cauchy optical model. The results showed that the refractive index at 550 nm was increased from 2.17 to 2.23 with the increased annealing temperature. The results from the spectrophotometer confirmed that the optical spectra for the WO3 thin films were decreased. This study demonstrated that, the thin film annealed at 400°C exhibited the slightly lower transparency, which corresponded to the results from the GIXRD and SE analyses.
Vertically Aligned Ag Nanorod Arrays for Trace Cypermethrin Detection
Authors: Limnonthakul Puenisara , Limwichean Saksorn , Eiamchai Pitak , Horprathum Mati , Supati Attawit , Nuntawong Noppadon , Patthanasetakul Viyapol , Chindaudom Pongpan
Published: June 2014

According to the growing interest in development of high-sensitivity surface-enhanced Raman scattering (SERS) substrates, this study focused on the fabrication of silver nanorods (AgNRs) based on the DC magnetron sputtering, with the glancing-angle deposition (GLAD) technique. The influence of incident angles on the film morphologies and SERS activities of the deposited films were investigated by field-emission scanning electron microscopy (FE-SEM) and Raman spectroscopy. With methylene blue as the test agent, the vertical aligned silver nanorods proved highly potential in highly sensitive SERS detections. The pesticidal cypermethrin were also used as the probe molecules to investigate for future practical applications. This work showed that the increase in the incident angle during the deposition helped promote the porosity of the AgNRs. The SERS signals were significantly enhanced from the vertically aligned silver nanorods grown at 85o incident deposition angle and 20 rpm substrate rotational speed.
A Study on Composition of Plaster Waste from Ornament Factory
Authors: Angnanon A. , Kanchanakul P. , Kaewkhao J. , Srisittipokakun N.
Published: June 2014

Plaster is a material which is widely used in Thailand. However, some variations of plaster that contain powdered silica or asbestos may present health hazards if inhaled. Asbestos is a known irritant when inhaled in powder form can cause cancer, especially in people who smoke, and inhalation can also cause asbestosis. Therefore, finding a way to recycle plaster waste has received attention. This study investigated the composition and phase of major plaster waste from ornament factory in Thailand by X-rays Fluorescence spectrometer (XRF) and X-Rays Diffractometer (XRD). The main compositions of new plaster and plaster waste by an XRF spectroscopy were SiO2, SO3 and CaO, they accounted for about 99.6 wt% of the total. The main phase of new plaster was found to be SiO2, CaSO4, CaO, S and Ca2Si form. The main phase of plaster waste was found to be SiO2 and CaSO4 form. These results indicated that plaster waste may be used as substitute or additive for silica source in other industry.
A Fabrication of Galvanic Cell from Pineapple Peel Residue in Agricultural Industries
Authors: Pancharoen A. , Poomjan S. , Taengtang T. , Srinuanjan K.
Published: June 2014

In this research, we present a fabrication of an electric generation experimental kit which is comprised of pineapple peel residue from agricultural industries. Juice from squeezing pineapple peel was used as electrolyte of a galvanic cell. Sufficient acidity of the juice could activate electrochemical reaction in the galvanic cell kit using a zinc plate and copper plate as electrodes. During the experiment, adjustable distances between the two electrodes were controlled to obtain maximum output voltage. It has been already known that a galvanic cell with a lower distance between electrodes could provide higher output voltage but both electrodes could not touch each other. Experimental results from controlling distances between the 2 electrodes showed that the galvanic cell kit could provide high output voltage of 1.00 V which was able to apply in electronic devices.
Thermal and Structural of Methyl Cellulose
Authors: Siriprom W. , Kongsriprapan S. , Teanchai K.
Published: June 2014

The present study aims to investigate the physicochemical properties of the methyl cellulose. The information of this investigate has been used to reference in preparing biodegradable film. It was observed that the Fourier Transform Infrared Spectroscopy (FTIR) spectroscopy show the hydrogen bond’s formation and the Energy Dispersive X-Ray Fluorescence (EDXRF) show the chemical and level of the composition element, which Copper (Cu) has the highest accumulate. Another that, the XRD spectra which investigated by X-Ray Diffraction (XRD) show the methyl cellulose had lowered crystalline. Another that, the Thermo-Gravimetric Analysis (TGA) was used to investigate the effect of heating and influence of thermal.
Quantum Field Theory Viewpoint of Refractive Index
Authors: Maksuwan Atirat
Published: June 2014

We rigorously investigate the refractive index by using the technique of the Green’s function. The propagator model of the polarization-free photon is created in quantum field theory viewpoint. The Green’s function is solved in detail with appropriate boundary originating an idea of amplitudes to propagate from place to place found in Richard Feynman's QED: The Strange Theory of Light and Matter (Princeton University Press, Princeton, New Jersey, 1985). The polarization-free photon is emitted from external sources or emitter in one medium and then propagates into another medium with the key idea: expression for amplitudes of scattering is a shrink and a tune by a certain amount, and is the same everywhere in one medium is given by determining the various contributions to probability amplitude coming from an integration over an arbitrary circular region of radius a. The purpose of this communication to establish the amplitude for the transmission of propagates by disregard about the material property. This amount is different for different materials, which corresponds to the “slowing” of the light is extra turning caused by the atoms in one medium scattering the light. The degree to which there is extra turning of the light goes through a given material is called its “index of refraction” for geometrical optics in classical physics.
Effect of Heat Treatment on Phase-Formation Behavior of Agricultural Material
Authors: Siriprom W. , Kuha P. , Kongsriprapan S. , Teanchai K.
Published: June 2014

In present study, the phase transformations upon heat treatment were investigated and assessment the possibilities to produce the raw material in the production of low-cost natural adsorbents which have appropriate physical and mechanical characteristics. The physical-chemical properties of agricultural material were identified by Energy Dispersive X-Ray Fluorescence (EDXRF), X-Ray Diffraction (XRD) and Fourier Transform Infrared Spectroscopy (FTIR) spectroscopy. The XRD pattern suggest that the Babylonia areolata shells sample have the aragonite phase while the rice husk and the coconut lumber sawdust have amorphous structure. After that, all samples were annealed at different temperatures ranging from 300 to 900°C, another that, all samples have been transform structural in to Oxide compound. Moreover, the chemical compositions were investigated by XRF and FTIR was developed for analysis of functional group and their chemical bonding characteristics.
The Effected of Single Point Incremental Forming Process Parameters on the Formed Part Surface Roughness
Authors: Rattanachan Kittiphat , Chungchoo Chatchapol
Published: June 2014

The single point incremental forming process (SPIF) are suited for sheet metal prototyping, because it is a low cost production process that produces sheet metal part without any used of die, and easy to adjust the part’s geometry by change toolpath. But the quality of forming parts is still in doubt. In some applications, such as mould cavity for rapid mould and the medical parts, in this case the inside surface roughness plays an importance role. In this paper, the SPIF process parameters that affected to the inner surface roughness were experimental studied. The investigated parameters are composing of tool feed rate, side overlap, depth step and tool radius. The 2k-p factorial experimental design was used to analyze the interaction between each parameter. The results showed that increasing feed rate and depth step decreased inner surface roughness. Reducing tool rotational speed and feed rate reduced inner surface roughness. So increasing depth step with decreasing side overlap reduced inner surface roughness. The large tool radius and lower side overlap improved inner surface roughness. The large tool radius and higher depth step improved inner surface roughness. And last, reducing tool rotational speed with larger tool radius, the inner surface roughness is decreased.
Structural and Optical Properties of Anatase-TiO2 Sputtered Nano-Thin Films
Authors: Tongwanichniyom Suree , Witit-Anun Nirun
Published: June 2014

Titanium dioxide (TiO2) nanothin films were deposited on unheated substrate, the glass slide and Si-wafer, by DC reactive magnetron sputtering with different substrate-target distance (dst), in range of 8 to 14 cm. The structural, surface morphology and transmittance spectrum of TiO2 thin films were characterized by grazing-incidence X-ray diffraction (GI-XRD), atomic force microscopy (AFM) and spectrophotometer, respectively. XRD results show that as-deposited TiO2 films with short substrate-target distance have only anatase crystal structure corresponding to the anatase in (101) and (200) plane, and turn to be amorphous with long substrate-target distance. The thickness and roughness varied from 50 nm to 142 nm and 1.6 nm to 3.5 nm, respectively. The as-deposited TiO2 films exhibited high visible transmittance. The optical constants of the films, refractive index (n) and extinction coefficient (k), were calculated by Swanepoel method, at 550 nm, was about 2.43 - 2.76 and 0.082 - 0.187, respectively. The energy band gap (Eg) of the as-deposited TiO2 films in the range of 3.20 - 3.25 was observed.
Structural and Optical Properties of ZrO2 Thin Films Deposited by Reactive DC Unbalanced Magnetron Sputtering
Authors: Witit-Anun Nirun , Chaiyakun Surasing
Published: June 2014

Zirconium oxide (ZrO2) thin films were deposited on Si-wafer and glass slide substrates by reactive DC unbalanced magnetron sputtering at different deposition times. A pure metallic zirconium target (99.97%) was sputtered in a gas mixture of argon and oxygen. The crystal structure was characterized by GI-XRD (grazing-incidence X-ray diffraction) whereas surface morphologies and films thickness were evaluated by AFM (atomic force microscopy). The transmittance spectrum was measured by spectrophotometer. The optical constants of the as-deposited films were calculated by Swanepoel method. It was found that the ZrO2 films deposited on silicon substrates showed a highly monoclinic phase (-1 1 1). The as-deposited films showed high transmittance in visible range. The thickness and roughness varied from 155 nm to 502 nm and 3.1 nm to 3.6 nm, respectively, with increasing of deposition times. The optical constants namely refractive index (n) and extinction coefficient (k), at 550 nm, was about 1.9 - 2.1 and 0.0003 - 0.0009, respectively. In addition, the energy band gap (Eg) of the as-deposited film was approximately 4.17 eV.
Considering Backoff Algorithms Efficiency Focused on the Effect of Wall and Floor Materials for Indoor Radio Network
Authors: Sartthong Jesada , Sittichivapak Suvepon
Published: June 2014

In this paper, we introduce a new theoretical scheme for evaluating the performance of backoff algorithms focusing on multiple types of wall and floor material such as: concrete, wood, glass and brick. The proposed scheme is an extension and combination between Bianchi and Multi-wall-floor model, by applying discrete Markov chain theorem. In addition, we also propose two backoff algorithms which can improve the saturated throughput efficiency of IEEE802.11 wireless local area network (WLAN). The proposed backoff algorithms are called Binary Exponential Increment Half Decrement backoff algorithm (BEIHD), and Half Binary Exponential Increment Double Decrement backoff algorithm (HBEIDD). The numerical results show that significant improvement saturated throughput of HBEIDD backoff algorithm operates well for plywood wall and wood floor materials in indoor environment.
Upconversion Luminescence and Optical Studies of Nd3+: Bi2O3–B2O3–P2O5 Glasses
Authors: Chanthima Natthakridta , Sangwaranatee Narong
Published: June 2014

The bismuth borophosphate glass matrix doped with Nd2O3 have been prepared by conventional melt quenching method with the molar compositions of 25Bi2O3 : 5B2O3 : (70-x)P2O5 : xNd2O3 (where x = 0.2, 0.4, 0.6, 0.8 and 1.0 mol%). The density, molar volume, optical absorption and upconversion luminescnece spectra were studied. It can be seen that the density is not depend on Nd2O3 concentration. The molar volume is tending to be decreased with increasing of Nd2O3 due to the decrease in the bond length or interatomic spacing between the atoms. Ten absorption bands at 427, 471, 510, 525, 580 , 622, 682, 743, 802 and 873 nm are observed, which could be ascribed to Nd3+ transitions from the 4I9/2 ground state to 2P1/2, 2G9/2, 4G9/2, 4G7/2, 4G5/2 + 2G7/2, 2H11/2, 4F9/2, 4F7/2 + 4S3/2, 4F5/2 + 4H9/2 and 4F3/2 levels. The upconversion luminescence band at 394 nm was observed and the highest emission intensity was obtained at 0.8 mol% of Nd2O3.
Temperature Difference of Thermoelectric Module on PIC-Microcontroller
Authors: Sangwaranatee Narong , Wongkampha T. , Kaseam E. , Sangwaranatee N.W. , Mekhum W.
Published: June 2014

This research is the study of electric power generated by the temperature difference below 100 °C of thermoelectric effect (cooling devices), which gets power from direct current and the electromotive force from thermoelectric module. In this research, a testing kit was designed to collect the output of temperature difference on the thermoelectric device, and compared the level of electric power of various modules in 2 different circuits; series and parallel. The result of the study showed that the higher differential temperature increased the value of electricity generation. Also, the electrical connection of thermoelectric module had an effect on power generating. When using 2 modules for each circuit, the series circuit generated more power than the parallel circuit.
Physical and Chemical Properties of Mineral in Soils of Cassava Cropping Area: A Case Study in Chonburi Province
Authors: Siriprom W. , Teanchai K. , Kongsriprapan S. , Kaewkhao J. , Sangwaranatee Narong
Published: June 2014

The chemical and physical properties of topsoil and subsoil which collected from the cassava cropping area in Chonburi Province have been investigated. The characterization of both soil sample were used X-Ray Diffraction (XRD), Energy Dispersive X-Ray Fluorescence (EDXRF) while FTIR used to confirmed the formation of intermolecular bonding and Thermo-Gravimetric Analysis (TGA) used for investigated the crystalline. It was found that, the XRD pattern indicated quartz phase. The chemical composition by XRF reported that the soils samples consist of Si, Al, Ca, Fe, K, Mn, Ti, Cr, Zn, Ag and Cu. and TGA results, noticed that the removal of moisture and organics material.
Effect of O2 Flow Rate on Structural and Optical Properties of Tantalum Oxide Thin Films Prepared by DC Reactive Magnetron Sputtering
Authors: Sangwaranatee Narong , Horprathum Mati , Kaewkhao Jakrapong
Published: June 2014

Tantalum oxide (Ta2O5) thin films have been deposited on glass substrates and silicon wafers (100) by dc reactive magnetron sputtering and with a 99.995% pure tantalum target. The effect of the oxygen flow rate on the crystallinity and optical properties were investigated. The films were characterized by X-ray diffraction patterns, UV-Vis spectrophotometer and spectroscopic ellipsometry. The results show that the deposition rate of Ta2O5 thin films was decreased with the increase in oxygen flow rate. In addition, Ta2O5 thin films deposited at oxygen flow rate higher than 6 sccm could be exhibited sufficiently oxide thin film, the transmittance spectrum percentage indicated 80%, which corresponded to the obtained optical characteristic.
A Study of Double Microring Resonator Behavior for 1.3 μm Optical Communication
Authors: Pornsuwancharoen N. , Tasakorn M. , Phromloungsri R. , Yupapin P.P.
Published: June 2014

A system that can be used to generate the new optical communication using a Gaussian pulse propagating within a nonlinear microring resonator double add/drop multiplexing system is discussed. By using the wide range of the Gaussian input pulses, for instance, when the input pulses of the common lasers with center wavelengths 1,300 nm are used. Achievements obtained have shown that very high capacity more than 300 channels for optical communication.
A Study of Triple Ring Resonator Behavior for Optical Communication
Authors: Klongklew Ura , Pornsuwancharoen Nithiroth , Chaiyasoonthorn Sawatsakorn
Published: June 2014

We propose a study triple ring resonator using a Gaussian pulse within the triple ring resonator system, whereas the chaotic signal can be generated within a microring device. We have also theoretically shown that the optical non-linear behaviours can be controlled and tuned by varying the couple coefficient (κ) between 0.20 and 0.95, with ring resonator radii between 10 and 20 μm, which is available for suitable result for communication. In application, the transmission of optical communication system , quantum communication and dens wavelength multiplexing.
A New Design Optical Tweezers by Triple Ring Resonator
Authors: Tasakorn M. , Pornsuwancharoen N. , Yupapin P.P. , Thongmee S.
Published: June 2014

We propose a new system of the multi-quantum tweezers array generation using a soliton generation control within the triple ring resonator system, whereas the dynamic tweezers can be generated within a microring device. By using the quantum processor, the entangle photon states of the tweezers can be formed, which is allowed to form the molecular quantum transmission. We have also theoretically shown that the optical tweezers can be controlled and tuned by varying the couple coefficient (κ) between 0.25 and 0.9, with ring resonator radii between 7 and 15 μm, which is available for molecule trapping. In application, the transmission of tweezers with different molecules or DNA can be performed, which is available for high density and security molecular transportation via the optical communication system.
Determination of Sucrose Concentrates Using Ellipsometry Technique and Transmission Spectroscopy
Authors: Viriyavathana P. , Sawangjaitham W. , Suchat S.
Published: June 2014

In this paper, the ellipsometry based on polarization technique used to determination of sucrose concentrates. And then we used multi-wavelength radiation from a halogen lamp provided spectral, is described and applied to the determination of optically active of sucrose. The instrument has no moving parts, and optical rotation measurements are an apparent absorbance. Apparent absorbance measurements can be combined with over a wide spectral range. Results obtained by this two technique have showed good.
Investigation of Graph-Based Detection in Iterative Decoding for Bit-Patterned Media Recording
Authors: Kovintavewat Piya
Published: June 2014

High-density bit-patterned media recording (BPMR) can be obtained by reducing the spacing between data bitislands in both the along-and across-track directions, thus leading to severe intersymbol interference (ISI) and intertrack interference (ITI) because of small bit and track pitches, respectively. Here, we propose to use the graph-based detector, instead of the trellis-based detector, in iterative decoding to combat the ISI and the ITI for a multi-head multi-track BPMR system. Specifically, the readback signal is sent to the graph-based detector before iteratively exchanging the soft information with a decoder. Experimental results indicate that at low to moderate complexity, the proposed scheme outperforms the existing schemes, especially at high recording density.
The Transmittance to Direct Irradiance due to Absorption by Precipitable Water Vapor in the Atmosphere
Authors: Phokate Sayan , Pisutthipong Nitiphat
Published: June 2014

This research aims to calculate the transmittance to direct irradiance due to absorption by precipitable water vapor in the atmosphere of Thailand, estimation of the absorptance by water vapor in the atmosphere and calculate the precipitable water vapor in the atmosphere. The precipitable water vapor in the atmosphere was calculated from upper air checking data relative humidity and temperature. The data were collected at four meteorological monitoring station located in Chiang Mai, Ubon Ratchathani, Bangkok and Songkhla during the years 1991-2010. The figures for precipitable water vapor obtained from this investigation were used to formulate a mathematical model relating to the precipitable water from four stations with surface climatological data, relative humidity and temperature at the same stations. The result showed that the relationship has a relatively high level of reliability. The precipitable water vapor obtained from upper air nearly is equal to the value from the model. The difference in the Root Mean Square Error (RMSE) is equal to 0.250 cm. Then, the researcher used a model to calculate the amount of precipitable water vapor at 85 meteorology stations nationwide. The result showed that the precipitable water vapor was less in the dry (November to March) and relative high in the rainy season (April-October). The average per year was found to be 4.559 cm. When analyzing the solar radiation absorption by water vapor in the atmosphere, found that the absorption is more or less depending on the precipitable water vapor in the atmosphere, which has an average annual as 15.53 percent. The transmittance to direct irradiance due to absorption average per year was found to be 84.51 percent.
Combined Coding Algorithm of LDPC Codes in Bit-Patterned Media Recording Channels
Authors: Prasartkaew Chutima , Kovintavewat Piya , Choomchuay Somsak
Published: June 2014

This paper presents a new coding algorithm of irregular low-density parity-check (LDPC) codes. This algorithm consists of two parts of block codes; parity bits was encoded using the magic square based algorithm (MSBA) which suitable for the short block (less than 500 bits) and the data bits, the rest part of all block codes, was encoded using the random number table. This proposed coding algorithm is called ‘Combined Coding Algorithm LDPC codes (CCA-LDPC codes)’ which can be used in bit-patterned media recording (BPMR) channels. The performance of the constructed codes was numerically simulated in BPMR channels model. The obtained performance of the proposed codes was compared with the comparable existing codes. The simulation results show that, at a block length of 4110 bit and code rate of 0.9, the proposed CCA-LDPC codes yields better performance than the existing ones, especially at high signal-to-noise ratio scenario.
Effect of SnO2 Addition into TiO2 Thin Films on Photocatalytic Activity and Hydrophilic Property
Authors: Sangchay Weerachai , Rattanakool Tanarat
Published: June 2014

The pure TiO2 and SnO2-TiO2 thin films on glass substrate were fabricated using a sol-gel dip coating technique. The thin films were annealed at the temperature of 700 °C for 2 h with the heating rate of 10 °C/min. The microstructures of the fabricated thin films were characterized by SEM and XRD techniques. The photocatalytic activities of the thin films were also tested by the degradation of methylene blue (MB) solution under UV irradiation. Finally, hydrophilic or self-cleaning properties of thin films were evaluated by measuring the contact angle of water droplet on the thin films with and without UV irradiation. It was found that 1 %mol SnO2-TiO2 thin films shows the highest of photocatalytic activity and provide the most self-cleaning properties.
Use of Cellular Automata for Modelling of the Material Erosion and Grit Entrainment during Discharge in EDM
Authors: Golabczak Andrzej , Konstantynowicz Andrzej , Golabczak Marcin
Published: June 2014

A combined mathematical model has been presented to evaluate the main physical processes taking place in the electro-discharge machining (EDM) gap. The model consists of electric field distribution evaluation by using the full Poisson equation for the environment of different electrical parameters as well as the electric charge distribution, and rends particles (grits) movement in the gap forced by diffusion as well as the electric field drag of charged grits. Both models are developed on the same rectangular grid which allows mutual influence of them.
Solution of Direct and Inverse Problems for Infiltration and Contaminant Adsorption in Partially Saturated Porous Media
Authors: Kačur Jozef , Minár J.
Published: June 2014

We discuss the numerical modelling of unsaturated-saturated flow in porous media and contaminant transport with adsorption in 1D. We developed an efficient numerical approximation which is a good candidate for solving inverse problems involving the determination of model parameters (hydraulic and geochemical). Also an adsorption/desorption model for mass transfer through the boundary of porous media (contact solid-liquid) is discussed, too. Our numerical solution is based on the MOL method where space discretization leads to the corresponding system of ODE. To collect the measurement data for inverse problems we consider both the gravitational and centrifugal infiltration driven forces. In series of numerical experiments we demonstrate the effectiveness of our method.
Characterization of the Effects of Active Filler-Metal Alloys in Joining Ceramic-to-Ceramic and Ceramic-to-Metal Materials
Authors: Aliya D. , Walker L.W. , Montz E. , Pastor S. , Abad A. , Hashim F.A. , Abdul-Latif A. , Al-Roubaiy A.O. , Oh Y.S. , Garmestani H. , Ula N. , Es-Said O.S.
Published: June 2014

This study investigated actively brazing Alumina-to-Alumina with Ag-Cu-Ti as the filler metal system and Alumina-to-Copper with Cu-Ti-Co as the filler-metal system. The research was conducted on four samples, two of which were alumina brazed to alumina (Samples 1 & 2), and the other two were alumina brazed to copper (Samples 3 & 4). The filler metal composition for each sample was as follows: Sample 1 consisted of Cu-96%, and Ti-4%; Sample 2 consisted of Ag-70%, Cu-26%, and Ti-4%; Sample 3 consisted of Cu-85%, Ti-10%, and Co-5%; and Sample 4 consisted of Cu-55%, Ti-40%, and Co-5%. The phase transformations between the filler and base metal of each brazed joint were studied using EDS, SEM, optical microscopy, and X-ray diffraction.
Test Matrix for Heat Exposure of Aluminum Alloys at Various Times and Temperatures
Authors: Al-Abduljabbar Abdulhamid , Es-Said O.S.
Published: June 2014

The purpose of this study is to characterize the effects of heat damage on the electrical conductivity and static mechanical properties of aluminum alloys. The data resulting from the experiments of thermal exposure of several aluminum alloys are used to model the relations that describe the dependence of the electrical conductivity and hardness on the two main variables of these experiments: the temperature and the time of exposure. The dependence of yield strength and ultimate tensile strength on hardness values is characterized. For each case, different materials (alloys) exhibit similar general trends although there are different coefficients for each material to satisfy the general relation.
About Thermo-Hydraulic Properties of Open Cell Foams: Pore Scale Numerical Analysis of Strut Shapes
Authors: Kumar Prashant , Topin Frédéric
Published: June 2014

The thermo-physical behavior of open-celled metal foams depends on their microscopic structure. Various ideal periodic isotropic structures of tetrakaidecahedron shapes with constant cross section of the ligament having circular, square, diamond, hexagon and star strut shapes with various orientations are studied. We have proposed a generalized analytical model in order to obtain geometrical parameters correctly and various relationships between different geometrical parameters and porosities (60-95%) are presented. We have also studied the flow parameters namely permeability and inertia coefficient for different strut shapes and various Reynolds number (0.00001<Re<3000). The range of solid to fluid phase conductivity ratios (λs/λf) studied is from 10 to 30000 for different porosities in local thermal equilibrium condition and an analytical correlation is proposed comprising geometrical parameters of foam structure.
The Role of Surface Area of ZnO Nanoparticles as an Agent for some Chemical Reactions
Authors: Alnarabiji Mohamad Sahban , Yahya Noorhana , Hamid Sharifah Bee Abdul , Azizli Khairun Azizi , Kashif Muhammad , Qureshi Saima , Alqasem Bilal
Published: June 2014

Synthesising zinc oxide nanoparticles (ZnO-NPs) to get certain characteristics to be applied in Enhanced Oil Recovery (EOR) is still challenging to date. In this work, the importance of high surface area of ZnO nanoparticles as EOR agent was highlighted. A simulation on density of state (DOS), band structure and adsorption energy of hydrogen and nitrogen gases on the surface of ZnO was carried out; it is observed that from the band structure of the band gap value for ZnO is 0.808ev. For the ZnO, Zn 4s states contribute to conduction band and O 2p states contribute to valence band. ZnO-NPs were synthesised using the sol-gel method by dissolving zinc nitrate hexahydrate in nitric acid and varying the stirring time (1 and 24h) and sintering time (30 and 40 min). A microwave oven was used for annealing ZnO without insulating the samples in any casket. The results show that 30 and 40 min of annealing and stirring for 1 & 24 h influenced the morphology and size of ZnO-NPs. These parameters could be tailored to generate a range of nanoparticle morphology (flask and/with agglomerated nanoparticles in a corn shape) obtained by Field Emission Scanning Electron Microscope (FESEM) and hexagonal crystal, determined by X-ray diffractometer (XRD), with the mean size of 70.5 & 74.9 nm and a main growth at the peak (101). The prepared sample via stirring for 24h and sintering for 40 min was chosen to prepare ZnO nanofluid because it has the highest surface area (BET) among the rest of samples, 0.23 m2/g. 10% of Original Oil In Place (OOIP) was recovered successfully to prove that ZnO is a good candidate to be applied in some chemical reactions. Moreover, it was found that ZnO is a promising catalyst for ammonia synthesis based on the adsorption energy of hydrogen and nitrogen gases (-1.05 and-1.60 kcal/mol respectively).
Lattice Boltzmann Method Applied to Diffusion in Restructured Heterogeneous Media
Authors: Walther E. , Bennacer R. , Desa C.
Published: June 2014

This paper shows the use of the Lattice Boltzmann Method (LBM) for the simulation of the diffusion equation in complex heterogeneous media. The theoretical background of the method for both homogeneous and heterogeneous media is developed. A simple method to determine the safe use conditions of the LBM is proposed, accompanied by a practical example. The range of interest and condition of non-negativity of the equilibrium distributions are identified for a broad range of diffusive properties ratios.
Plasma Polymerization of Hexamethyldisiloxane and Tetraethoxysilane Thin Films for Humidity Sensing Application
Authors: Guermat N. , Bellel A. , Sahli Salah , Segui Yvan , Raynaud Patrice
Published: June 2014

Humidity sensitive layers elaborated from pure HMDSO and TEOS by PECVD technique have been studied. Humidity sensing properties including impedance relative humidity (RH) and current RH characteristics were investigated. TEOS films show higher sensitivity and excellent linearity over the explored range of humidity (20–95% RH). However, HMDSO films exhibits a small response and recovery of about 8 and 34 s for humidification and desiccation, respectively, in addition to very low hysteresis (2%). Structural analyses of sensitive layers were characterized by Fourier transform infrared spectroscopy (FTIR).
Study of Modification of PP/EPDM Compounds by Ultraviolet and Gamma Radiation Using Recycled Polypropylene Collected after EPDM Waste Processing as Raw Materials
Authors: Pereira Nilson Casimiro , Terence Mauro Cesar , Bruzadin D.F. , Fechine G.J.M. , de Miranda Leila F. , Peres Renato Meneghetti
Published: June 2014

As the polypropylene resin of high consumption, has as a consequence, the same feature among the resins most discarded after use. This generates high amount of waste in landfills, causing environmental problems, because the polypropylene presents difficulty in the short term, degradation by micro-organisms in the trash. Thus, this resin recycling proposals are always welcome, raising the possibility of reuse, and reducing the concentration of the landfills, thereby helping to minimize the negative effects of its disposal on the environment. Some manufacturers of rubber products, using as raw materials EPDM, report that are discarded after processing the waste, largely in landfills. Thus, the proposed reuse of byproduct, also will not contribute to the degradation of the environment. The aim of this work was to produce compositions (mixtures) with different concentrations of polypropylene and EPDM recycled materials, and evaluate the effect of ultraviolet and gamma radiation, rheological properties, thermal, mechanical and morphological, of the composites. The compounds obtained showed that waste rubber modified thermoplastic properties of polypropylene when irradiated by both UV radiation, such as gamma radiation.Comparing the hardness and impact tests, it was observed that the values ​​decreased with respect to the material not irradiated (UV or gamma). This effect is due mainly to the presence of the EPDM rubber, because the PP when subjected to gamma radiation or UV at low doses has an increase in mechanical properties.
Neural Network-Based Prediction of Effective Heat Storage Coefficient of Building Materials
Authors: Singh Ramvir , Dabas Manju
Published: June 2014

In the present paper, we have employed the application of artificial neural networks (ANN) to predict effective heat storage coefficient (HSC) of building materials. First we prepared a database to train and test the models developed here. Two types of architectures from different networks are developed, one with three inputs and the other with four inputs mixed architecture combining an ANN with a theoretical model developed by us previously. These ANN models are built, trained and tested by the feed forward back propagation algorithm, to obtain the effective properties of building materials from the properties of their constituents. Feed forward back propagation neural network structure has been developed, which includes an input layer, a hidden layer and an output layer. The number of neurons in the input layer is equal to the number of input parameters and the number of neurons in the output layer is equal to the output parameters. A good agreement has been found between the predicted values using ANN and the experimental results reported in the literature.
An Overview of the Interdiffusion Studies in Mo-Si and W-Si Systems
Authors: Roy Soumitra , Prasad Soma , Paul Aloke
Published: June 2014

The growth of phases by reactive diffusion in Mo-Si and W-Si systems are compared. The crystal structures of MSi2 and M5Si3 phases (M = Mo, W) are similar in these two systems. However, the diffusion rates of the components change systematically with a change in the atomic number. Integrated diffusion coefficients in both phases increase with an increasing atomic number of refractory elements i.e. from Mo to W. On the other hand, the ratio of diffusivities of the components decreases. This indicates a relative increase in the diffusion rates of the metal components with increasing atomic number and a difference in defects concentrations in these two systems.
Phase Transformations and Recrystallization in Cold-Rolled Al–Mn, Al–Sc–Zr and Al–Mn–Sc–Zr Alloy
Authors: Vlach Martin , Stulíková Ivana , Smola Bohumil , Kudrnova Hana , Kekule Tomáš , Malek Jaroslav , Ocenasek Vladivoj
Published: June 2014

The effect of cold-rolling on mechanical and electrical properties, microstructure and recrystallization behaviour of the AlMn, AlScZr and AlMnScZr alloys was studied. The materials were investigated during isothermal annealing at 300, 400, 500 and 550°C and during step-by-step quasilinear annealing from 200°C up to 600°C with a heating rate of 100 K/h followed by subsequent isothermal annealing at 600°C/5 h. Precipitation reactions were studied by electrical resistometry and (micro) hardness measurements. The microstructure development was investigated by electron microscopy and electron backscatter diffraction examinations. The hardening effect is due to uniformly distributed Al3Sc and/or Al3(Sc,Zr) particles. The distinct changes in resistivity of the alloys above ∼ 300°C are mainly caused by precipitation of Mn-containing particles. It has a negligible effect on hardness. Phase transformations in the AlMn and AlMnScZr alloys are highly enhanced by cold rolling. The precipitation is dependent on the deformation degree – the more deformation the more intensive precipitation of the Mn-containing particles. The combination of Mn, Sc and Zr additions to Al substantially suppresses recrystallization at 550°C. A partial recrystallization was observed in the AlScZr alloy and AlMnScZr alloy after annealing 550°C/60 min and 550°C/760 min, respectively. The decomposition sequence of the supersaturated solid solution of the AlMnScZr alloy is compatible with the decomposition sequence of the AlScZr system accompanied and/or followed by the formation of Mn-containing particles.
Development of Novel "Sponge-Type" Sorbent for Elimination of CS: Preparation of Ammonium Molybdophosphate - Polyurethane Foam (AMP-PUF) Composite and its Sorption Behavior
Authors: Murakami Masahiko , Ohnishi Simpei , Hirano Masaya , Itoh Kenichi , Saito Toshiaki
Published: June 2014

Aiming to develop sponge-type sorbent, composite involving ammonium molybdophosphate (AMP) and polyurethane foam (PUF) was prepared. A 33 - 60 % (w/w) of AMP granule was kneaded with base-liquids of two-component rigid type PUF. The composite was able to selectively and quantitatively adsorb 0.5-500 µL of Cs+ from 10 mL solution of 500 µL of Na+, K+, Mg2+ and Ca2+ as matrices ions; distribution coefficient (kd) was 4.2 × 106 and 1.3 × 105 mL/g for without and with matrices, respectively. Maximum sorption capacity was of 42.9 mg/g.
Comparative Study of Antibacterial Efficiency of M-TiO2 (M = Ag, Cu) Thin Films Grown by CVD
Authors: Maury Francis , Mungkalasiri Jitti , Bedel Laurent , Emieux F. , Dore Jeanne , Renaud Francois N.R.
Published: June 2014

M-TiO2 (M = Ag, Cu) nanocomposite layers were grown by pulsed direct liquid injection chemical vapor deposition (DLICVD) on various substrates to produce bactericidal surfaces with long term activity. Monodisperse Ag nanoparticles (NPs) with an average size of 5-10 nm are embedded in an anatase matrix. A bactericidal behavior determined by the JIS Z 2801 standard test was found for Ag-TiO2 films for Ag ≤ 1 at. % and above. Higher Ag content is not necessary since efficiency is already at its maximum (relative activity 100%). By contrast, using Cu as antibacterial agent, a larger size distribution of metal particles was found (20 to 400 nm). Cu-TiO2 films exhibit a bactericidal behavior if their thickness is higher than 100 nm and Cu content ≥ 3.5 at. %. These coatings are still antibacterial after 5 months of aging and their efficiency has decreased by only 35%.
Effect of RE3+ Codopant on Afterglow Time of SrS:Eu2+,RE3+
Authors: Takahashi Aoi , Umegaki Tetsuo , Kojima Yoshiyuki
Published: June 2014

The longest afterglow time of an orange-red- emitting SrS:Eu2+,Pr3+ afterglow phosphor by visible light irradiation was about 1010 minutes was previously achieved by varying the synthetic conditions such as amount of Li+ added, reduction temperature, reduction time, and initial Eu/Sr and Pr/Sr atomic ratios in previous paper. Therefore, this study reports on the effect of the RE3+ codopants on the afterglow time of an orange-red-emitting SrS phosphor by visible light irradiation. SrSO4:Eu3+,RE3+(RE3+ = Tm3+, Er3+, Tb3+, Nd3+, Pr3+, Ce3+, and La3+), which was the precursor for SrS phosphors, was synthesized via a liquid-phase reaction. SrSO4:Eu3+,RE3+ was pressurized at 10 MPa for a few minutes to form a compact, which was then heated under a H2S or Ar-H2 (5 mol%) reductive atmosphere at 1400 °C for 2.5 h to generate the SrS:Eu3+,RE3+ afterglow phosphor. The emission color of the SrS:Eu2+,RE3+ afterglow phosphor was orange-red and its emission peak was observed around 610 nm. The excited band of the phosphor was in the range of visible light more than 440 nm. The emission and excitation spectra of the SrS:Eu2+,RE3+ afterglow phosphor were not dependent on the RE3+ codopants. However, the afterglow time of SrS:Eu2+,RE3+ phosphor was increased with the increase of ionic radius of the coactivator. The longest afterglow time of SrS:Eu2+,Ce3+ phosphor by irradiating for 5 minutes at 1000 lx which was created from a D65 lamp was 1376 minutes. This was 9.5 times longer than that of a commercial available phosphor (CaS:Eu2+,Tm3+).
Electric Pulse Induced Resistive Switching in the Narrow Gap Mott Insulator GaMo4S8
Authors: Querré Madec , Corraze Benoit , Janod Etienne , Besland Marie Paule , Tranchant Julien , Potel Michel , Cordier Stephane , Bouquet Valérie , Guilloux-Viry Maryline , Cario Laurent
Published: June 2014

We report here on resistive switching measurements on GaMo4S8 a lacunar spinel compound with tetrahedral Mo4 clusters filled with 11 electrons. Alike other clustered lacunar spinel compounds with 7 or 8 electrons per cluster, this narrow gap Mott Insulator exhibits both a volatile and a non-volatile unipolar resistive switching. We found that the volatile resistive switching appears above a threshold electric field in the 7 kV/cm range. For electric field much larger than this threshold, the resistive switching becomes non-volatile. Successive electric pulses allow switching back and forth between high and low resistance states. All these results demonstrate that the narrow gap Mott insulator compound GaMo4S8 could be a relevant candidate for a new type of non-volatile memory based on an electric field induced breakdown of the Mott insulating state.