bluuebunny/crossref_metadata_2025 huggingface dataset:
Coherent Ring Currents in Chiral Aromatic Molecules Induced by Linearly Polarized UV Laser Pulses
Authors: Kanno Manabu , Koho Hirohiko , Mineo Hirobumi , Lin Sheng Hsien , Fujimura Yuichi
Published: March 2013

In recent years, laser control of electrons in molecular system and condensed matter has attracted considerable attention with rapid progress in laser science and technology [. In particular, control of π-electron rotation in photo-induced chiral aromatic molecules has potential utility to the next-generation ultrafast switching devices. In this paper, we present a fundamental principle of generation of ultrafast coherent ring currents and the control in photo-induced aromatic molecules. This is based on quantum dynamics simulations of π-electron rotations and preparation of unidirectional angular momentum by ultrashort UV laser pulses properly designed. For this purpose, we adopt 2,5-dichloro [(3,6) pyrazinophane (DCPH) fixed on a surface, which is a real chiral aromatic molecule with plane chirality. Here π electrons can be rotated along the aromatic ring clockwise or counterclockwise by irradiation of a linearly polarized laser pulse with the properly designed photon polarization direction and the coherent ring current with the definite direction along the aromatic ring is prepared. This is contrast to ordinary ring current in an achiral aromatic ring molecule with degenerate electronic excited state, which is prepared by a circularly polarized laser [2]. In this case, π electrons rotate along the Z-axis of the laboratory coordinates, while for the present case electrons rotate along the z-axis in molecular Cartesian coordinates. It should be noted that signals originated from the coherent ring currents prepared by linearly polarized ultrashort UV lasers are specific to the chiral molecule of interest.
Zero-Bias Operation and Beam Energy Dependence of Diamond Sensors
Authors: Conte Gennaro , Spadaro Stefano , di Castro Elisabetta , Carni Marco
Published: March 2013

A prototype sensor able to work at zero bias has been fabricated using high quality single crystal diamond and two Schottky junctions. The detector's current in the dark is 3.2±0.2×10-14 A, while the current measured under irradiation with 1.6 Gymin-1 of 6 and 15 MV x-ray photons is 7.5±0.2×10-10 A. The sensitivity is strongly dependent on the applied voltage whereas at zero bias we have measured 37±2 nCGy-1, independent of the beam quality. The sensitivity increases with a sub-linear trend up to 100V, as the sensor photocurrent dependence on voltage. Moreover, the device shows very fast response on the rise and fall transients, with the signal stability under irradiation better than 0.3%. The linearity with the dose rate is spread over three orders of magnitude from 1.3×10-3 Gymin-1 to 1.2 Gymin-1 as measured with Co-60 photons.
Improving Amorphous Selenium Photodetector Performance Using an Organic Semiconductor
Authors: Abbaszadeh Shiva , Allec Nicholas , Karim Karim S.
Published: March 2013

In this paper, a thin layer of perylene tetracarboxylic bisbenzimidazole (PTCBI) is investigated as a potential hole-blocking contact in an a-Se photodetector. The behavior of the device was characterized as a function of electric field under light and dark conditions. It was found that the PTCBI layer permits operation at high electric fields (>>10 V/μm) while maintaining a dark current density below 200 pA/mm2. Short pulse experiments were performed to assure that charge accumulation at the organic/a-Se interface is negligible and does not reduce the electric field in the a-Se layer. The detector investigated uses a simple low temperature fabrication process based on widely available semiconductor materials that can be easily integrated into current large area digital imager manufacturing processes.
Magnetite: Synthesis and Characterization
Authors: Giannouli Christina
Published: March 2013

Magnetite nanopowder is a nanostructured magnetic material which is of great importance due to its electric and magnetic properties at room temperature. There are quite enough methods to produce magnetite. In the present work, four samples of magnetite powder were produced, the first three with the alkaline precipitation method from aqueous solution of mixed Fe (II)/Fe (III) salts, without any surfactants and the last one with the micro emulsion method. The prepared powders have been characterized using transmission electron microscopy, Raman and FT-IR spectroscopy and x-ray diffraction in order the structure and the morphology of magnetite to be examined. The produced magnetite powders have a size range of 10-12±2nm and the chemical composition of magnetite.
Optimization and Application of NTC Thick Film Segmented Thermistors
Authors: Nikolic Maria Vesna , Aleksic Obrad.S. , Radojcic Branka M. , Lukovic Miloljub D. , Nikolic Nenad , Djuric Zorka
Published: March 2013

NTC thermistor paste for printing thermal sensors on alumina was formed of very fine Ni0.5Cu0.2Zn1.0Mn1.3O4 thermistor powder obtained by a combined mechanical activation/thermal treatment process, organic vehicle and glass frit. Sheet resistivity was measured using an R-test matrix and it was much lower than the value determined for pure nickel manganite thermistors. The thermistor exponential coefficient was calculated from the R[ diagram measured in the temperature range-30 to +120°C in a climatic chamber. Thick film segmented thermistors with reduced dimensions (optimized construction) were printed sequentially layer by layer, dried and fired at 850°C/10 min in air. Electrodes were printed of PdAg conductive and solderable paste. The samples obtained were characterized by electrical and thermal measurements. The obtained NTC segmented thermistors with reduced dimensions were applied in a thermal sensor for water flow in the water mains. It contained a cold thermistor for measuring input water temperature and a self-heating thermistor for measuring the dependence of water current on water flow rate at a set input voltage power. Initial measurements show that the thermal sensor system requires a low input voltage power making it much easier and safer for operation.
Piezoelectric Immunosensors for Toxins' Detection in Foodstuffs
Authors: Karaseva N.A. , Ermolaeva T.N.
Published: March 2013

The procedures of detecting trace concentrations of okadaic acid and staphylococcal enterotoxin A in foodstuffs by the piezoelectric immunosensors have been developed. The conditions for immobilizing antibodies to toxins on the surface of the sensors gold electrode have been facilitated. The calibration curves for the detection of okadaic acid and staphylococcal enterotoxin A are linear in the range of concentrations 5500 ng·ml-1 and 1-80 ng·ml-1, the limits of detection are 1.4 and 0.4 ng·ml-1 correspondingly. The time of analysis does not exceed 30 min. The sensors were tested in detecting okadaic acid in fish products and in detecting staphylococcal enterotoxin A in chicken meat and milk.
Self-Calibrating Optical Displacement Sensor
Authors: Babković Kalman , Nagy László F. , Krklješ Damir
Published: March 2013

Commercially available reflective optical sensors can be used as displacement sensors which in turn can be used in vibration monitoring, positioning, force-measurement and other applications. The sensor output depends in all cases on the distance between the component and a suitable reflective surface. In this paper a sensor system applicable to vibration measurement (e.g. monitoring a vibration-generating machine mounted on elastic isolation mountings) is presented where a special mechanism enables the controlled adjustment of the reflective surfaces position. This feature allows continuous operating point adjustment while the sensor measures vibration. On the other hand, during the intervals when the vibration measurement is not active (e.g. the machine is not in use), the system can be used to automatically calibrate the sensor, i.e. to measure the dependence of the optical sensor output from the distance to the reflective surface. This allows accurate measurements under various circumstances: temperature change, optical component replacement, staining of the reflective surface, ingress of dirt etc. The reflective surface adjustment system is controlled by an embedded digital system which also controls the calibration procedure. Range depends largely on the type of reflective sensor. In case of the component TCRT1000 used in the experiments, range is up to 4 mm.
Microwave Synthesized CuO Nanoleaves as Nonenzymatic Glucose Sensor
Authors: Karunakaran C. , Manikandan G.
Published: March 2013

CuO nanoleaves have been synthesized by cetyl trimethyl ammonium bromide (CTAB)-assisted microwave method and characterized by powder X-ray and selected area electron diffractions, scanning and transmission electron microscopies and energy dispersive X-ray and electrochemical impedance spectroscopies. The CuO nanoleaves on graphite nonenzymatically sense glucose electrochemically. Cyclic voltammetic and chronoamperometric studies reveal the excellent catalytic activity of the modified electrode towards direct glucose oxidation. A wider linear range of glucose concentration and a shorter response time are observed. The detection limit of glucose is as low as 4µM and the CuO nanoleaves can be used as efficient electrochemical sensor.
Synthesis and Characterization of Silver-Poly(Methylmethacrylate) Nanocomposite
Authors: Puišo Judita , Baltrušaitis Valentinas , Lazauskas Algirdas , Guobienė Asta , Prosyčevas Igoris , Narmontas Pranas
Published: March 2013

Silver nanoparticles and polymethylmethacrylate (PMMA) nanocomposite was prepared in situ by photo-induced thermal reduction method. The interfacial interaction of Ag nanoparticles and PMMA polymer is investigated using Fourier transform infrared spectroscopy (FTIR). Optical properties of Ag/PMMA films were characterized by UV-Vis and FTIR absorption spectroscopy. Effects of the UV and heat-treatment time on the formation of silver nanoparticles in PMMA matric matrix were studied in detail. These investigations proposed new nanocomposite structures. They can be defined as plasmonic materials with improved optical properties. Ag/PMMA structures may found a number of technological applications: in optical devices, various plasmonic sensors or even in nanomedicine.
Molecular Imprinted Poly(Ethyleneco-Vinyl Alcohol) Nanofibers Electrospun on Gold Electrodes for Impedimetric Creatinine Sensing
Authors: Betatache Amina , Braiek Mohamed , Chateaux Jean François , Lagarde Florence , Jaffrezic-Renault Nicole
Published: March 2013

In this work, a biomimetic sensor elaborated by direct electrospinning of molecular imprinted poly (ethylene co-vinyl alcohol) (EVOH) onto gold electrodes was proposed for impedimetric creatinine detection. Dimethylsulfoxyde (DMSO) was selected as polymer solvent and creatinine (1% wt) was used as template. In the optimal conditions of fabrication (20% wt EVOH, electrical voltage: 20 kV, collection distance: 30 cm), the sensor response was proportional to log [creatinine concentratio in the 1 fg.L-1-1 μg.L-1 range. We also showed that the sensor could be reused at least three times and that the response of the non imprinted polymer control sensor, prepared the same way but in absence of creatinine, was very low.
An Improved Technique for the Exfoliation of Graphene Nanosheets and Utilization of their Nanocomposites as Fuel Cell Electrodes
Authors: Yürüm Yuda , Okan Burcu Saner , Okyay Firuze , Yürüm Alp , Dinç Fatma , Görgülü Neylan , Gürsel Selmiye Alkan
Published: March 2013

Graphene is a flat monolayer of carbon atoms tightly packed into a two-dimensional 2D honeycomb lattice. The graphene sheets in graphite interact with each other through van der Waals forces to form layered structure. The first graphene sheets were obtained by extracting monolayer sheets from the three-dimensional graphite using a technique called micromechanical cleavage in 2004 [. There are numerous attempts in the literature to produce monolayer graphene sheets by the treatment of graphite. The first work was conducted by Brodie in 1859 and GO was prepared by repeated treatment of Ceylon graphite with an oxidation mixture consisting of potassium chlorate and fuming nitric acid [. Then, in 1898, Staudenmaier produced graphite oxide (GO) by the oxidation of graphite in concentrated sulfuric acid and nitric acid with potassium chlorate [. However, this method was time consuming and hazardous. Hummers and Offeman found a rapid and safer method for the preparation of GO and in this method graphite was oxidized in water free mixture of sulfuric acid, sodium nitrate and potassium permanganate [.
Effects of Graphite Mold on Cooling Process of Fused AZS 33# Refractory
Authors: Yuan Fei , Yang Dao Yuan , Wang Ting , Li Zhan
Published: March 2013

This study analyzed effects of different thickness(TH) and thermal conductivity of graphite mold on temperature, liquid phase percentage and conductive heat flux, the cooling process of fused cast AZS 33# refractory could be simulated by using COMSOL Multiphysics software. The results show that: when the graphite mold thickness increased, surface center temperature and liquid phase area of casting decreased gradually, but conductive heat flux increased gradually, the cooling rate of casting increased, which were helpful to form fine crystals near the casting surface. When using conventional graphite mold, the optimum thickness was less than 40mm, while using the high thermal conductivity graphite mold, the optimum thickness was 50mm. So the rapid and homogeneous cooling process of casting could reduce the possibility of material crack and obtain fine crystals structure of material; comparing with conventional graphite mold, high thermal conductivity graphite mold was more beneficial to achieve uniform and fast cooling process to improve the performance and passing rate of products.
Preparation of Ultrafine Al(OH)3 Powders from Scrap Aluminum
Authors: Xu Jing
Published: March 2013

The homogeneous precipitation pathway was explored to synthesize ultrafine powders of Al(OH)3. In the experiment, the scrap aluminum were used as raw material . The effects of reaction time, reaction temperature, stirring speed, concentration of sulphuric acid and dispersant on the preparation process were investigated. The results showed that ultrafine Al(OH)3 powders can be yielded and well-controlled under the following optimal conditions: the concentration of sulphuric acid 3.0 mol•L-1, reaction temperature 0-4 °C, stirring speed 900 r.min-1 and reaction time 15 min. The diameter less than 100nm of sphericity Al(OH)3 particles with the narrow distribution were successfully obtained. The Al(OH)3 powders was analyzed with scanning electron microscopy , infrared spectrometer. The Al(OH)3 powders have good dispersancy and purity is more than 90%. The operation of the experiment was very simple, and the particles were separated easily.
Properties Related Phase Evolution in Multilayer Silicate Ceramics
Authors: Boussois K. , Tessier-Doyen N. , Chateigner D. , Blanchart P.
Published: March 2013

The use of ceramic processes inducing a microstructural organization at the grain scale favors the improvement of strength and toughness. With layered structures, it is possible to design the microstructural characteristics of materials, leading to increased threshold strength. Layered structures can be arranged to control the local residual stresses causing elastic mismatches between dissimilar materials and crack deflection at interfaces. In this way, multilayer composites from kaolinite and alumina or mullite fibers were shaped by tape casting and staked by thermo-compression, or by centrifugation. During sintering, they show at strong anisotropic behavior, which is in correlation with different activation energy for sintering. Mullite growth is also anisotropic, inducing the formation of an organized micro composite microstructure. The mechanical and elastic properties are correlated with the organization degree of mullite crystals, due to the formation of an interconnected mullite network in the microstructure. It is also shown that variations of mechanical and elastic properties are correlated with the texture index obtained by Quantitative Texture Analysis from X-ray data. The anisotropy of the elastic properties is evidenced by different values of Young’s modulus in directions parallel and perpendicular to the casting direction. Beside, the crack growth resistance is governed by discontinuities along layer boundaries and fiber interfaces.
The Study on Composition and Heat Treatment of the Fei-Color Jade
Authors: An Mei , Ye Dong , Xing Qiu Yu , Zu En Dong
Published: March 2013

In this paper, the color-causing elements and mineral composition of the Fei-color Jade （During the epigenetic oxidation,the oxide mineral of iron filled and disseminated in the gravel fissures and mineral gap,then the jade will produce Fei -color,which includes yellow and red.）were analyzed by the X-ray fluorescence spectroscopy and X-ray diffraction techniques in order to carry out systematic study the Fei-color Jade. The results showed that the Fei color emerald color concentration was proportional to the iron content. Manganese was the main reason causing sepia tone in Fei -color jade. The color of yellow jade was caused by limonite and it would be showing red hue when the imonite partly transformed into hematite due to dehydration. Meanwhile, the upper limit temperature of the heat treated Fei–color jade was about 580 °C.
Study on the Microstructure of Inorganic Fullerene-Like WS2
Authors: Zhang Tao , Ma Tian , Gao Peng Gang , Shen Feng Chuan , Zhang Jian Chun
Published: March 2013

The microstructure of the inorganic fullerene-like WS2 was analyzed by scanning electron microscope (SEM) and high-resolution transmission electron microscopy (HRTEM) in this work. The results indicate that the diameter of the WS2 particles is around 60~120 nm. The WS2 consists mainly of hollow polyhedral structures with quasi-spherical shape that is capable of sustaining much higher shock pressures due to a more uniform stress distribution on its surface. This characteristic made it a super shock wave absorbing material, which is great worth of bullet proof applications. This work is expected to develop a new type bullet-proof composite which can be used in the army.
Crystal Structure Stabilization of Gadolinium Aluminum Garnet (Gd3Al5O12) and Photoluminescence Properties
Authors: Li Jin Kai , Li Ji Guang , Wu Xiao Li , Liu Shao Hong , Li Xiao Dong , Sun Xu Dong
Published: March 2013

To suppress the thermal decomposition and to stabilize the crystal structure of Gd3Al5O12 (GdAG) garnet, doping GdAG with smaller Ln3+ (Ln=Tb, Dy, Ho, Er, Tm, Yb, Lu, and Y, respectively) to form (Gd,Ln)AG solid solutions was proposed in work. Carbonate precursors of (Gd,Ln)AG with an approximate composition of (NH4)x(Gd,Ln)3Al5(OH)y(CO3)z•nH2O were synthesized via coprecipitation from a mixed solution of ammonium aluminum sulfate and rare earth nitrate, using ammonium hydrogen carbonate as the precipitant. The precursors and the calcination derived oxides were characterized using FT-IR spectroscopy, DTA/TG, XRD, BET and FE-SEM. The results showed that smaller Ln3+ doping can indeed stabilize GdAG against its thermal decomposition to a mixture of GdAlO3 (GdAP) and Al2O3 phases at elevated temperatures and at the same time effectively lowers the temperature for garnet crystallization. The carbonate precursors are loosely agglomerated and the resultant (Gd,Ln)AG powders show good dispersion and a fairly uniform particle morphology. The (Gd,Ln)AG solid solutions exhibit decreasing lattice parameters along with decreasing radius of the dopant ions at the same dopant content of 50 at%. Photoluminescence properties of some of the garnet solid solutions are also studied. The materials developed herein may potentially be used for photoluminescent and scintillation applications.
Structure and Luminescence Characteristics of Yttrium Hydroxide Nanosheets Doped with Tb3+
Authors: Zhang Lin , Li Cai Xia , Jiang Dan Yu , Feng Tao , Li Qiang
Published: March 2013

Tb3+ doped Yttrium hydroxide nanosheets were successfully synthesized from layer compound of Y2(OH)5NO3 doped by Tb3+. Layer compound was obtained by hydrothermal reaction at 120°. After ion exchange reaction with sodium benzoate under the microwave condition, the layer space of the compound increases from 0.907 nm to 1.452 nm. stable nanosheets sol was obtained after exfoliation under ultrasonic condition. The structure of layer compound and the morphology of nanosheets were determined by XRD,SEM, Zeta Size, Zeta Potential, TEM and FL. The luminescence properties of terbium hydroxide nanosheets doped with Tb3+ were examined; the relationship between structure and spectra was discussed.
Preparation of Porous Silicon by Magnesiothermic Reduction from Serpentine
Authors: Ma Bin , Huang Zhao Hui , Fang Ming Hao , Liu Yang Ai , Chen Shu Sen
Published: March 2013

In order to obtain the porous silicon, amorphous silica was prepared from serpentine by leaching experiment The XRF results shows that the leach residues almost compose of amorphous silica, the content is 92.37%, via magnesiothermic reduction, The XRD results shows the amorphous silica was reduced to porous crystal silicon successfully and The SEM results shows they have similar morphology. One of the most important properties of porous silicon was characterized by PL and with an excitation at 365 nm. an emission centered in the blue region.
Evaluation of High Temperature Interfacial Bonding Strength of Ti3SiC2-Al2O3 Joint in Air
Authors: Wan De Tian , Bao Yi Wang , Liu Xiao Gen , Tian Yuan , Li Run Run
Published: March 2013

Ti3SiC2-Al2O3joint with strong interface has potential high temperature applications because it combines with the merits of hard ceramics and soft ceramics. The safety is strongly dependent on the interfacial bonding strength between Ti3SiC2and Al2O3. In this work, the cross-section method was suggested to evaluate the tensile and shear bonding strength for Ti3SiC2-Al2O3joint from room temperature to 800 °C in air. A novel testing fixture made of SiC was designed and machined to avoid the bending stress at the bonding surface during the testing process. It is indicated that the measured shear bonding strength is usually higher than tensile bonding strength for Ti3SiC2-Al2O3joint. Both the tensile and shear bonding strength are decreased with the increment of testing temperatures. At 800 °C, the tensile and shear bonding strength are declined to be about 43.15% and 45.02% compared with those at room temperature, relatively. The mechanism for the strong interface between Ti3SiC2and Al2O3is also discussed.
Thermal Stress Analysis of Photovoltaic Hollow Glass Based on ANSYS
Authors: Li Wei Hong , Li Cong , Qiu Yan
Published: March 2013

This article through to hollow photovoltaic glass service in the process of temperature test, by using the finite element simulation of the temperature change caused by the thermal stress, using the finite element simulation of the temperature change caused by the thermal stress. According to the heat conduction equation and boundary condition, derivation hollow photovoltaic through the finite element software to hollow photovoltaic glass plate thermal stress for numerical simulation and research. Adopted in structural analysis directly define temperature load method analysis force hollow photovoltaic glass thermal stress. Use the finite element software to hollow photovoltaic glass plate thermal stress for numerical simulation and research. For the known temperature field distribution situation, adopted in structural analysis directly define temperature load method analysis force hollow photovoltaic glass thermal stress. Through the finite element software ANSYS to calculate different unit was carried out and the numerical simulation, the results show that the analytical solution and the numerical solution has good goodness of fit. The proposed calculation formula for engineering design has the certain reference value.
Effect of Ball Milling on the Properties of Zirconia Powder Prepared by Alcohol-Aqueous Coprecipitation Method
Authors: Zhang Yun Feng , Wang Kai Jun , Hu Jin
Published: March 2013

Zirconia precursor was prepared by an alcohol-aqueous coprecipitation process from raw materials of ZrOC12•8H2O and ammonia ,the zirconia powders were subsequently obtained by calcination of the precursor at 600°C and ball milling. The properties of zirconia powder prepared by alcohol-aqueous method after ball-milling had been researched by BET,XRD,TEM and laser granularity instrument.The results show that by using ball-milling the agglomerate size can be effectively decreased but the primary particle size is hardly affected .The surface area of powder after calcinated can be markedly increased and narrowed size distribution can be gained by ball-milling, but the phase structure of the powder had not been changed.
Effect of CrTiAlN Coatings on High-Temperature Oxidation Behavior of H13 Steel
Authors: Zhang Hao , Duo Shu Wang , Fei Xiao Yan , Xu Xiang Min , Liu Ting Zhi , Wang Yu Bin
Published: March 2013

CrTiAlN hard coatings have been deposited on H13 steel for improving the oxidation resistance by Closed Field Unbalanced Magnetron Sputter Ion Plating (CFUMSIP). The phase components, surface and section morphology of H13 steel before and after oxidation were analyzed by XRD and SEM. The results showed that the columnar crystal film possesses three major parts, i.e., the internal Cr bonding layer, the intermediate CrN transition layer, the external CrTiAlN gradient coating. The selective oxidation of Cr element was found on the surface of uncoated H13 steel while oxidation, but a continuous protective layer was not formed because of low Cr content, finally a lot of alpha Fe2O3 particles took place on the surface of H13 steel owing to the oxidation of the matrix element. O element can diffuse much more easily through the coating and oxide scales at 800 °C, and spallation and cracks were not found during the oxidation. These results indicated that the CrTiAlN coating have excellent high-temperature oxidation resistance at 800 °C.
Preparation and Thermoelectric Properties of Ca3Co4O9 Ceramics with Parallel Sheet Shaped Pores
Authors: Wang Hua Dong , Sun Xu Dong , Ding Xue Yong , Zhang Mu , Li Xiao Dong , Li Ji Guang , Huo Di , Liu Shao Hong
Published: March 2013

Ca3Co4O9 powders were synthesized by a solid-state reaction method. Porous Ca3Co4O9 ceramics with parallel sheet shaped pores were prepared by a template sacrifice method using epispastic polystyrend (EPS) hollow spheres as the templates. During compaction of the green body, the EPS hollow spheres change into EPS discs due to the pressing force. After sintering, the pores in the Ca3Co4O9 ceramics are sheet shaped, well distributed and parallel to the pressing surface of compaction. The value of ZT merit of the porous Ca3Co4O9 sample obtained with 10 wt% EPS spheres is 0.0489. It was found that the ZT merit value can be improved by changing the density of sample to achieve a high ratio of electrical conductivity to thermal conductivity.
Research on Electrode Propertie of Heater for Planar Oxygen Sensor
Authors: Wang Zheng , Wang Tai Bin , Yang Jian , Feng Tao , Xia Jin Feng , Jiang Dan Yu
Published: March 2013

Through screen-printing technology, we prepared heater which is used for planar oxygen sensor with YSZ solid electrolyte, alumina insulating layer and platinum(Pt) paste, then sintered at different temperatures.Analysis the properties of Pt electrode through aging time test and thermal shock test. The results show that 1100°C is the best sintering temperature for Pt electrode.Resistance and surface morphology of Pt electrode changed obviously with aging time increasing and 100 times thermal shock is not enough to affect the morphology of electrode and the change of resistance has no regularity.
Test of Relative Translucency for Four All-Ceramic Core Material after Veneering Ceramic
Authors: Chen Jian Feng , Zhao Li Sheng , Zhao Yan , Deng Bin , Gu Bin , Yi Yuan Fu , Shao Long Quan , Wang Zheng , Wen Ning
Published: March 2013

Objective: To study the relative translucency of 4 veneered and glazed all-ceramic systems core material, including Vita In-Ceram Alumina, Vita In-Ceram Zirconium, Ivoclar Vivodent Empress and Colored Zirconia. Methods: Under standard black and write background, the surface light reflectivity of 4 veneered all-ceramic systems core material was determined with contact color difference meter, and the ratio of Yb /Yw was calculated. Results: After veneered, the relative translucency of 4 core materials all declined, and ranged from 0.8015 of Colored Zirconia to 1.00 of In-Ceram zirconia, among of that Empress II and Colored Zirconia were most transparent. Conclusion: Among the groups, there is no significant difference between Empress II and Colored Zirconia(IL1,IL2,IL3). Compared with Vita In-Ceram Alumina and Vita In-Ceram Zirconium, Vita In-Ceram Alumina(AL1) has significant difference. There is no significant difference between Vita In-Ceram Zirconium and Vita In-Ceram Alumina(AL2,AL3,AL4).
Effect of Post-Core Materials on the Color Value of Four Dental All-Ceramic Cores
Authors: Lu Rong Jian , Wang Cheng Long , Zou Jing Cai , Yi Yuan Fu , Shao Long Quan , Wen Ning , Gu Bin , Liu Yi Han , Deng Bin
Published: March 2013

The aim of this study were to compare the color value of four kinds of dental all-ceramic cores (IPS e.max Press,Zenostar,Lava Zirconia and Upcera Zirconia) on three different post-core materials.All-ceramic core materials were made into samples at the diameter of 10mm and the thickness of 0.50.02mm.Their color value on the post-core material of noble metal,Co-Cr alloy and resin were respectively determined with chromatism instrument.It was showed that the color value of four all-ceramic cores were statistically different.IPS e.max Press was most obviously affected by post-core materials,while Upcera Zirconia the weakest.Lava Zirconia and Zenostar were influenced to a certain degree.In conclusion,non-mental post-core was preferable for IPS e.max Press,Upcera Zirconia was fit for any post-core materials.
Performance Research on Photovoltaic/Thermovoltaic Solar System in Building Integrated Photovoltaic (BIPV)
Authors: Wei Chen Guang , Bao Yi Wang
Published: March 2013

A novel hybrid photovoltaic/thermovoltaic solar system (PV/TV) was designed with PV cells combined with heat collector and thermoelectric generator. This PV/TV model can collect heat from the solar panels to reduce its surface temperature, and then to generate electricity by using of temperature difference technology and devices. In this paper, electricity generation performance of PV/TV system between April to October was tested and discussed. The application of this system in photovoltaic building was discussed. The results indicate that overall efficiency of this PV/TV system is higher than that of a pure PV system, and about 5%-15% efficiency increase.
Testing and Evaluation on the Chloride Ion Penetrability of Concrete under Compressive Stress
Authors: Jiang Yu Chuan , Huo Da , Teng Hai Wen , Xu Ji Ne
Published: March 2013

Chloride ion penetrability of concrete under and after compressive stress was tested in the paper. Four stress level (the ratio of the pressure load and ultimate load) was set: 20%, 40%, 60% and 80%. Chloride ion penetrability of concrete was tested using a rapid test method of electric flux. The results indicated that the electric flux of concrete under compressive stress was influenced by stress level, and the electric flux of concrete was first decreased and then upward with stress level increasing. The electric flux of concrete of different strength grade was sensitivity to compressive stress differently, and the lower the strength grade of concrete, the high sensitivity to compressive stress. The electric flux of concrete after compressive stress was related with crack recovery, and there was a significant effect of only more than 60% stress level on the electric flux of concrete. The evaluation of chloride ion penetrability of concrete structure should take into account the loads.
Investigation about Dilution Ratio Effect on X-Ray Intensity
Authors: Dai Ping , Liu Yu Bing , Yan Ran , Zhang Ya Zhen
Published: March 2013

In this paper, influence coefficient of flux (αi,f) on X-ray intensity was proposed, by which the X-ray intensity of fusion beads with different dilution ratio can be corrected to the standard value. Hence, the unknown sample of random dilution ratio can be determined by the standard working curve after corrected withαi,f. It was found that αi,f obtained by the proposed experimental method can be applied in correction of fluorescence intensity in the routine analytical work with satisfactory results. There is no necessary of exact weighing for the sample and the flux with the correction of αi,f. Furthermore, the procedure of routine analytical work can be simplified greatly without getting the L.O.I ahead of weighing, by which the working efficiency can be improved as well.
SiC-TiB2 Composite Densified by Pressureless Liquid-Phase Sintering
Authors: Chen Yu Hong , Wu Lan Er , Sun Wen Zhou , Jiang Yong , Lu You Jun
Published: March 2013

Particle reinforced SiC composites with the addition of TiB2 were fabricated in range of 1750°C to 1950°C by pressureless sintering by utilizing liquid phase with AlN-Y2O3 as sintering additives. The effective of sintering aids in densification, the mechanical properties of sintered sample and the microstructure had been investigated in this paper. The results showed that the best densification behaviors occurred in AlN:Y2O3 at 60 :40%mol ratio not at eutectic point. Adding TiB2 to SiC matrix increase the toughness and decreased the hardness. Microstructure analysis showed that the increasing of toughness was due to the crack deflection with some contribution intergranular fracture mechanism.
Three-Dimension Impedance Representation for Microwave Absorptive Ceramics
Authors: Liu Heng , Zeng Zhao Yang , Guo Yi Min
Published: March 2013

The application of three-dimension impedance representation for microwave absorptive ceramics was investigated. Based on transmission line theory, the electro-magnetic property of the ceramics was equivalent to impedance of a three-dimensional impedance network, and the surface effect was described by an added layer with certain impedance. Finally the usability of this representation was discussed by comparing the calculated data with the measurement results.
The Programming of Dentistry CCS/CCM Software
Authors: Zhao Yan , Zhao Li Sheng , Chen Jian Feng , Deng Bin , Gu Bin , Yi Yuan Fu , Shao Long Quan , Wang Zheng , Wen Ning
Published: March 2013

Objective: We aimed to develop a multi-functional CCS/CCM (Computerized Color Selecting/Computer Color Matching) software so as to provide more practical colorimetric software for clinical use and further researches. Methods: This software used the 6 dental prosthetic materials and color data from 4 shade guide system which were most frequently-used in clinic currently as basic database, to program 5 functional blocks including respectively CCS/CCM system; Dental Material Chromatic Value System; Vita Information System; Transformation of Colorimeter System; and Chromatic Value Difference Analysis. These modules had the functions of information inquiry of different types of dental materials and their corresponding chromatic value, color matching, transforming, and color difference analysis. Results: The software had a convenient operation interface which could guarantee a stable performance. Containing various shade block and chromatic value, and transformation among different colors, this software analysed the color difference in the database, improved the accuracy and reliability of dental color choosing, and, to some extent, increased the color repetition rate of prosthesis. Conclusion: The software could well meet the needs of clinical dental colorimeter and choosing, increase the color repetition rate of prosthesis, and easily finish the transformation among different colors. It had more functions to adapt clinical need.
Study on Preparation and Properties of Yttria Stabilized Zirconia Solid State Electrolyte
Authors: Liu Wei , Liu Ge Ming , Peng Niu Sheng , Sun Da Zhi
Published: March 2013

Abstract. Currently, Yttria-stabilized zirconia solid state electrolyte are widely used in various fields . The basic performance of Yttria-stabilized zirconia (5YSZ) prepared by different synthesis methods and sintering temperatures are studied in this paper ,their phase compositions and microstructure are studied with XRD and SEM. The ionic conductivity of 5YSZ sintered at different temperature are studied with A.C. impedance spectroscopy measurement.
Preparation and Properties of Sr2NaNb5O15 Lead-Free Piezoelectric Ceramics by Sol-Gel Method
Authors: Zhang Tian Hang , Zhao Jin Qiu , Liu Yang Ai , Huang Zhao Hui , Fang Ming Hao
Published: March 2013

Sr2NaNb5O15 ceramic powders have been synthesized by sol-gel method, ceramics were sintered via a pressureless sintering method. The effect of calcining temperature on the phase composition and microstructure of ceramic powders were investigated by TG-DSC, XRD and SEM analyses. The influence of sintering temperature on density, microstructure and properties of the ceramics were systematically analyzed. The results showed that the optimal calcining temperature was 1300°C, the average size of ceramic powders was about 3μm. When the sintering temperature was 1300°C, the ceramics showed optimized densiﬁcation and electrical properties(ρ=4.663 g/cm3, d33=45 pC/N, εr=1126, tan=0.027, Ec=17.91 kV/cm, Pr=6.72 μC/cm2, Ps=9.45 μC/cm2)
Preparation and Characterization of Sg. Sayong Clay Material for Biocatalyst Immobilization
Authors: Edama Nurul Aini , Sulaiman Alawi , Ku Hamid Ku Halim , Mohd Rodhi Miradatul Najwa , Musa Mohibbah , Abd Rahim Siti Noraida
Published: March 2013

This study was conducted to characterize Sg. Sayong clay so that it can be applied as a supporting material for the immobilization of biocatalyst in the bioconversion of wastewater into biofuel. The clay sample was physically and chemically characterized using Nitrogen Adsorption, X-Ray Diffraction (XRD), X-Ray Fluorescence (XRF), Fourier Transform Infrared Spectroscopy (FTIR), Inductively Coupled Plasma-Atomic Emission Spectrometry (ICP-AES) and Field Emission Scanning Electron Microscopy (FESEM). The results obtained showed that the clay composed of SiO2 (57.4%), followed by Al2O3 (32.5%), K2O (4.9%), Fe2O3 (3.8%) and traces amount of Ca, Mg, Ma, and Ti. The results also showed the clay type was kaolinite with some presence of quartz, illite, montmorillonite and microcline. The clay was also successfully coated onto the wire-mesh and immobilized with biocatalyst for further bioconversion study.
Preparation of Polyacrylonitrile Nanofibers with Controlled Morphology Using a Constant-Current Electrospinning System for Filter Applications
Authors: Munir Muhammad Miftahul , Nuryantini Ade Yeti , Khairurrijal Khairurrijal , Mikrajuddin Abdullah , Iskandar Ferry , Okuyama Kikuo
Published: March 2013

Polyacrylonitrile (PAN) fibers with average diameters in the range 100 nm with beaded morphology were prepared by a constant current electrospinning system. The fiber morphology could be easily varied by controlling the flow rate and electric current during the electrospinning process without changing the precursor solution. It was found that the use of lower flow rates resulted in more beaded fibers while the number of beads increases. The electric current could control the fiber morphology in which the beaded number (the number of beads or the beaded fibers) decreased as the electric current increased. It was also found that diameter and length of the beaded fibers increases as the electric current increases. Therefore, these results are able to be applied to find optimal conditions in obtaining high performance filter media.
Blue Luminescent of ZnO:Zn Nanocrystal Prepared by One Step Spray Pyrolysis Method
Authors: Panatarani Camellia , Muharam Dunden Gilang , Wibawa Bambang Mukti , Joni I Made
Published: March 2013

A blue luminescent of ZnO:Zn nanocrystal has been successfully prepared by one step spray pyrolysis method without reducing gas atmosphere. Zinc acetate dihydrate aqueous solutions (0.05 M) were atomized by ultrasonic atomizer. The atomizer used an air as carrier gas with 1, 3 and 5 L/min flowrate. The tubular reactor was set at 500, 600 and 700oC. As prepared samples were characterized by means of x-ray diffraction spectroscopy and scanning electron microscope-energy dispersive x-ray spectroscopy (SEM-EDS). The crystal size of as prepared particles calculated by Scherrer’s equation give 10-20 nm. The luminescent properties of as prepared particles were measured using spectrofluorophotometer. The highest photoluminescent intensity of particles irradiated with excited wavelength of 250 nm was obtained from samples prepared using 5 L/min carrier gas with temperature of tubular reactor 700oC. High intensity of blue luminescent was obtained due to oxygen vacancy in ZnO:Zn.
Controlling the Crystallite Size of Zinc Oxide Nanorods via Chemical Bath Deposition and Post-Hydrothermal Treatment
Authors: Sholehah Amalia , Yuwono Akhmad Herman , Rimbani Cyndi Rinaldi
Published: March 2013

ZnO nanorods were deposited on ITO glass substrate via chemical bath deposition at low temperature of 90°C. The seeding solution was made by dissolving zinc nitrate tetrahydrate and methenamine in cool water (5°C). The as-synthesized ZnOs were further subjected to post-hydrothermal treatment series.The results of scanning electron microscope (SEM) studies showed that the ZnO nanorods were grown as vertically-aligned hexagonal structure, while x-ray diffraction (XRD) patterns showed a high intensity of [002] peak. The absorption spectra of the as-synthesized sample indicated a strong absorption peak near the UV region. After post-hydrothermal treatments, the absorption was slightly shifted to visible region. The ZnO nanorods sample derived from post-hydrothermal treatment at 150°C for 12 hours has the largest crystallite size of 269.402 nm and the lowest band gap energy, Eg value of 3.205 eV.
Electrochemical Properties of P-Doped Silicon Thin Film Anodes of Lithium Ion Batteries
Authors: Arie Arenst Andreas , Lee Joong Kee
Published: March 2013

Silicon would seem to be a possible candidate to replace graphite or carbon as anode materials for lithium ion batteries based on its potential high capacity of 4200 mAhg-1. The main problem that must be solved for commercial application of silicon as anode material was the poor cyclic performance due to severe volume expansion during repeated charged-discharged cycles and its low electrical conductivity. In this work, we proposed Phosphorus doped (P-doped) Si films as anodes in lithium ion batteries. The electrochemical properties of the silicon based electrodes were examined by means of charge-discharge and impedance test. In comparison with the bare silicon electrode, the P type silicon electrode exhibited higher specific capacity of 2585 mAhg-1 until the 50th cycle. It was attributed to the improved electrical conductivity of Si film and reduced charge transfer resistance
Enhancement Performance of Dye-Sensitized Solar Cells from Black Rice as Dye and Black Ink as Counter Electrode with Inserting Copper on the Space between TiO2 Particle’s by Using Electroplating Method
Authors: Yuliza Elfi , Saehana Sahrul , Rahman Dui Yanto , Rosi Memoria , Khairurrijal Khairurrijal , Mikrajuddin Abdullah
Published: March 2013

In this study, we report well performance of Dye Sensitized Solar Cell (DSSC) coated with copper (Cu) by using the electroplating method. The Cu nanoparticle was impregnated into the pore of the titanium dioxide (TiO2) thin film. Particle contact between Cu and TiO2 plays important role to reduce the recombination effect of the electron and also lead to increase the electron transport in DSSC cell. Here, we used natural dye extracted from black rice and carbon from black ink as counter electrode. It is found that efficiency of DSSC coated with Cu nanoparticle is higher than pure DSSC which is obtained from I-V characterization. It shows that efficiency of DSSC is about 0.019% without coating Cu and enhanced about 0.105% after coating Cu. The analysis of internal resistance of DSSC was measured from Electrochemical Impedance Spectroscopy (EIS) characterization.
Implementation of Likhachev’s Model into a Finite Element Program
Authors: Terriault Patrick , Brailovski Vladimir
Published: March 2013

Shape memory alloys have become very popular over the past few decades, mainly as actuators or superelastic devices. Their complex behavior complicates the design process of these applications, and several models have been developed to assist design engineers in this endeavor. One of these models, the structure-analytical theory proposed by Likhachev, is particularly attractive because it is physically grounded and capable of dealing with tensorial stress and strain states. Unfortunately, its stress-controlled formulation has hindered its implementation in displacement-based finite element programs. This paper presents an adaptation of Likhachev’s model leading to a strain-controlled formulation based on an iterative algorithm and a proportional controller. The resulting model is implemented in ANSYS and a simple finite element analysis is carried out to illustrate its appropriate functioning.
Effect of Martensitic Transformation on the Optical Spectra of Cu-Mn-Al Alloy
Authors: Kudryavtsev Yuri V. , Kokorin Volodymyr V. , Kozlova Larisa E. , Iermolenko Volodymyr N. , Konoplyuk Sergiy M.
Published: March 2013

The effect of martensitic transformation on the transport and optical properties of Cu-4.9Mn-23.4Al (at.%) alloy is reported. The resistivity measurements revealed the transformation temperatures Ms =284K and Af=303K. The optical properties of Cu-4.9Mn-23.4Al (at.%) alloy have been investigated at several temperatures near the region of austenite-martensite transformation. It was shown that intraband absorption is dominates in alloy for ħω < 2.5 eV energy range. Plasma Ωp and relaxation γ frequencies of free charge carriers for Cu-4.9Mn-23.4Al (at.%) alloy were evaluated at several temperatures on the basis of Drude analysis of the alloy optical properties in the intraband absorption region. The growth of electrical resistance induced by martensitic transformation upon alloy cooling obtained directly from the resistivity measurements correlates nicely with the results derived from the optical measurements and can be explained by the reduction of the plasma frequency Ωp as well as increase in relaxation frequency γ of free charge carriers.
Addressing Retained Austenite Stability in Advanced High Strength Steels
Authors: Pereloma Elena V. , Gazder Azdiar , Timokhina Ilana B.
Published: March 2013

Advances in the development of new high strength steels have resulted in microstructures containing significant volume fractions of retained austenite. The transformation of retained austenite to martensite upon straining contributes towards improving the ductility. However, in order to gain from the above beneficial effect, the volume fraction, size, morphology and distribution of the retained austenite need to be controlled. In this regard, it is well known that carbon concentration in the retained austenite is responsible for its chemical stability, whereas its size and morphology determines its mechanical stability. Thus, to achieve the required mechanical properties, control of the processing parameters affecting the microstructure development is essential.