bluuebunny/crossref_metadata_2025 huggingface dataset:
A Review on Biosynthesis of Nanoparticles Using Plant Extract: An Emerging Green Nanotechnology
Authors: Mie Ropisah , Samsudin Mohd Wahid , Din Laily B.
Published: March 2013

The development of reliable and eco-friendly metallic nanoparticles needs some consideration on the chemical procedures involved in the synthesis of nanomaterials. The conventional methods in the production of metallic nanoparticles generate a large amount of hazardous byproducts. Thus, there is a need for ‘green chemistry’ that includes a clean, nontoxic and environment-friendly method of nanoparticle synthesis [1]. As an alternative, biological methods are considered safe and ecologically sound for the nanomaterial fabrication [2]. Therefore, in this review special attention is focused on the biosynthesis of nanoparticles from natural resources as compared as ordinary chemical method. Biosynthesis of nanoparticles using plant is a new development of green nanotechnology beneficial to environmental and to the plant itself. It also plays a significant role in the field of biology and medicine.
Influence of Different Types of Silanes on the Properties of Nanocomposite PMMA: TiO2 Thin Films
Authors: Lyly Nyl Ismail , Habibah Zulkefle , Sukreen Hana Herman , Rusop Mohamad
Published: March 2013

This paper reported the effect of silane on the electrical properties of the nanocomposite poly(methyl methacrylate): titanium dioxide (PMMA:TiO2) films. Different types of silane were added directly into the nanocomposite PMMA:TiO2 solution. Electrical properties result shows that when different silane were use in the nanocomposite solution give different electrical properties. Sample 1 (without silane) and 4 (trimethoxymethylsilane) shows the highest resistivity and lowest leakage current density. Meanwhile sample 3 (triethoxyvinylsilane) indicate that are not a suitable silane to be added into the nanocomposite PMMA:TiO2 solution because it produce poor insulator behavior.
Sol-Gel Derived Nanomagnesium Oxide: Influence of Annealing Temperature on the Dielectric Layer Properties
Authors: Habibah Zulkefle , Nurashikin Arshad Adillah , Lyly Nyl Ismail , Nurbaya Zainal , Rusop Mahmood Mohamad
Published: March 2013

Nano-magnesium oxide, MgO film was successfully prepared at various annealing temperatures (400, 450, 500 and 550°C) by using sol-gel method. The behaviour of the MgO as a dielectric layer was investigated in term of its electrical behaviour, relative permittivity and structural properties. The leakage current density obtained was below 10-9 A/cm2 in which is suitable to be used as dielectric layer. Resistivity and relative permittivity values were found to fluctuate with applied annealing temperatures and it was revealed that these changes were related to the surface morphology of the prepared nano-MgO films. Interesting surface morphology was observed for film annealed at 500°C, in which the film formed an island structure, composed of nano particle MgO in range of 45 to 74 nm.
Effects of Oxygen Flow Rate on Nanostructured ZnO Thin Films
Authors: Ahmad S. , Md Sin N.D. , Berhan M.N. , Rusop Mahmood Mohamad
Published: March 2013

Zinc Oxide (ZnO) thin films were deposited on thermally oxidized SiO2 by varying the oxygen flow rate. The deposition process were done using radio frequency (RF) magnetron sputtering at various oxygen flow rate ranging from 0 to 40 sccm. The surface morphology and crystallinity were analyzed by field emission scanning electron microscopy (FESEM) and X-Ray Diffractometer (XRD) respectively. The average thickness and deposition rate decreases with an increase of oxygen content. The grain size was measured by FESEM and it was found that it is also decreasing with the increased of oxygen flow rate. The films grown with 10 sccm oxygen shows the highest (002) peak however it is expected that the sample deposited with 40 sccm oxygen exhibit the highest sensitivity toward NH3 gas due to the highest surface to volume ratio.
A Comparison Study on the Heat Transfer Behavior of Aqueous Suspensions of Rod Shaped Carbon Nanotubes with Commercial Carbon Nanotubes
Authors: Mohamad Imran Syakir , Chitrambalam S. Thiru. , Hamid Sharifah Bee Abdul , Chin W. M. , Yau K.H. , Febrian Idral
Published: March 2013

Carbon nanotubes (CNTs) are said to be among the most potential materials in applications of nanodevices, nanocomposites and nanostructure due to their excellent mechanical and physical attributes. CNTs were first discovered by S. Iijima in 1991 where he has reported in his article the synthesis of needle-like tubes by using an arc-discharge evaporation. After the immense discovery, the number of research on CNTs has increased significantly, focusing on their mechanical characteristics, dynamics properties and applications in nanotechnology. This paper attempts to present a review of a quite number of publications on CNTs and their dynamic properties. The main topics covered in this review are the applications of CNTs, their dynamic characteristics including the modeling and simulation of vibrating CNTs, and finally the vibration modes of CNTs.
High Transparency Characteristics of Zinc Oxide Thin Films Annealed at Different Temperatures
Authors: Rodzi A.S.M. , Mamat Mohamad Hafiz , Berhan M.N. , Rusop Mahmood Mohamad
Published: March 2013

Zinc Oxide thin film has been prepared by sol-gel spin-coating techniques and has three steps preparation were includes. They were solution preparation, thin film deposition and characterization process. The film were prepared to investigate the annealing temperatures depend with two environments were hot and room temperatures. Annealing temperatures were set up into five temperatures 200°C, 300°C, 400°C, 500°C, and 600°C were heated inside furnace. The characterization of ZnO thin film was measured by UV-Vis Spectrometry which to measure the transmittance of ZnO have when through the medium. The transmittance was investigated by use glass as a substrate. The optical properties showed when increased annealing temperatures, so the high UV was transmit. From that, the absorption coefficient of ZnO also can also investigate too. The surface morphology in increasing annealing temperature has a small size and less porosity between particles.
Characteristics of Humidity Sensor Fabricated Using Nanostructured ZnO Thin Film by Sol-Gel Method
Authors: Mansor M.S. , Mamat Mohamad Hafiz , Mohamad Z. , Rusop Mohamad
Published: March 2013

We have investigated the morphology and sensitivity characteristics of nanostructured ZnO thin film prepared by sol-gel method from different molarities of zinc nitrate hexahydrate and hexamethylenetetramine (HMT) solutions. ZnO thin film coated glass substrates were used to growth the ZnO structures and have been annealed at different temperatures. The morphology of the samples was observed by scanning electron microscopy (SEM) and their sensitivity characteristics were measured by using the I-V measurement. The SEM studies shows that the nanostructured ZnO was denser at higher molarities and I-V measurement demonstrates that the nanostructured ZnO having higher sensitivity at higher molarities and higher annealing temperatures.
Electrical Characteristic of UV Sensor Using Nanostructured Al Doped ZnO Thin Film
Authors: Musa Mohamed Zahidi , Mamat Mohamad Hafiz , Rusop Mohamad
Published: March 2013

The electrical properties of nanostructured Aluminum (Al) doped Zinc Oxide (ZnO) thin films based ultraviolet (UV) sensor prepared by sol-gel spin-coating method have been investigated. Uniform nanoparticles Al doped ZnO have been deposited with high absorption coefficient at UV region and low absorption coefficient properties in visible and near-infrared (NIR) region. I-V spectra show high sensitivity characteristic of UV sensor with fast response after UV light exposure.
Optical Properties of Al Doped Zinc Oxide Nanorods Thin Film Deposited by Immersion Technique
Authors: Muhamed S.Z. , Mamat Mohamad Hafiz , Rusop Mohamad
Published: March 2013

We investigated the effect of immersion time on optical, electrical properties and surface morphology of nanostructured Aluminium (Al) doped Zinc Oxide (ZnO) thin films prepared by immersion technique. UV-Vis-NIR spectra indicate that the transmittance of the samples decrease with immersion time. Electrical properties study reveals the nanostructured Al doped ZnO thin film at 1 hr shows the lowest resistivity compared to other samples. Surface morphology results as characterized by scanning electron microscope (SEM) show that the Al doped ZnO nanorods quantity increased with immersion time.
Effect of Etching Time on Electrical and Optical Properties of Porous Silicon
Authors: Yusop S.F.M. , Azaman N. , Rafaie Hartini Ahmad , Amizam S. , Abdullah Saifollah , Rusop Mohamad
Published: March 2013

The characterized on porous silicon layer by using photoluminescence (PL) and I-V measurement (I-V) has been done. Porous silicon was formed by electrochemical etching on (100) p-type Si wafer substrate with the constant current density (20mA/cm2) and variable the etching time. The samples ware prepared under various etching time and properties of porous silicon depend on an etching time. Porous silicon has been used in humidity sensors to detect humidity through changes of its electrical properties. The samples of porous silicon were characterized by using Photoluminescence Spectroscopy (PL) that used to characterize optical properties while I-V Measurement (I-V) used to characterize porous silicon junction properties using a linear voltage source. The result shows PL intensity is increase while the wavelength is decrease for etching time of PSi is longer. For the I-V measurement result shows the etching time affect the resistance of sample due to its porosity.
The Influence of TiO2 Photoanode Morphology for Scattering Enhanced Properties of Dye-Sensitized Solar Cell
Authors: Abdullah Mohd Hanapiah , Lyly Nyl Ismail , Musa Mohamed Zahidi , Rusop Mahmood Mohamad
Published: March 2013

Effect of PEG on the TiO2 electrode morphology for scattering enhanced properties of the modified paste containing TiO2 sol-gel mixed with Degussa P-25 were investigated. The high surface area of the scattering centres in this study were formed by using nano size particles ascribed from TiO2 sol-gel while the sub-micron size particles were utilized from the reaction of PEG on the Degussa P-25 particles. The pore size distributions were tailored by varying the PEG content in the fabricated electrodes. Higher surface area with adequate pore size of P30 electrode has contributed to higher JSC and efficiency (η) of 11.35450 mA/cm2 and 2.479624 %, respectively. Photocurrent action spectra of IPCE of the DSSC exhibit the maximum of 42 % at 550 nm correspond to the P30 TiO2 electrode. Overall results suggest that the incorporation of TiO2 sol-gel component mixed with TiO2 paste derived from commercially available nanopowder could enhance surface area as well as serves for better light scattering effect, while PEG addition creates adequate pore size distribution to maximize the dye adsorbed on the TiO2 electrode.
Effect of Hydrothermal Growth Temperature on the Morphology and Structural Properties of Synthesized TiO2 Nanowires
Authors: Asiah Mohd Nor , Achoi M.F. , Mamat Mohamad Hafiz , Khusaimi Zuraida , Abdullah Saifollah , Rusop Mohamad
Published: March 2013

Titanium dioxide nanowires have successfully prepared by hydrothermal method. The effect of hydrothermal growth temperature on the morphology and structural properties of TiO2 nanowires have been investigated. It was observed that at low temperature of 100 °C, the formation of nanowires was at early stage, while hydrothermal treatment at 130 °C showed the TiO2 precursor acquired enough energy for formation of the nanowires. Increased the temperature to 200 °C was formed the bundle of nanowires in microsize. The diameter of nanowires increased as the temperature increased. The TiO2 nanowires produced at temperature of 150 °C and annealed at 500 °C showed highest crystallinity with anatase phase.
A Comparative Study of TiO2 Nanocoated Mild Steel Surface Properties between Short and Long Sputtering Time of RF Magnetron
Authors: Achoi M.F. , Asiah Mohd Nor , Rusop Mohamad , Abdullah Saifollah
Published: March 2013

TiO2 nanocoated mild steel surface has been successfully prepared via 100 watt of RF magnetron sputtering by using TiO2 target and sputtering condition was performed in 80sccm argon gas. The studied was done in comparing the surface properties of TiO2 nanocoated mild steel between short term and long term sputtering time at 5 and 60 minutes, respectively. From the results, we have found that the long-term sputtering time producing good surface coating with lower surface roughness at 0.033 nm with thickness in nanometer scale is 169 nm via AFM. Through Auger study revealed that the coating attributed Ti and O elements at energy of 383.48 eV and 483.44 eV, respectively. It was also showed that the intensity of that element high at about 100k a.u. in long-term compared to 55k a.u. short-term of sputtering time. It is thus showed that producing coating depends upon manipulation of parameter in RF magnetron sputtering.
ZnO Nanostructures – Nanorods and Flower-Like on Si/Au Substrates by Solution-Immersion Method in Different pH of Precursor
Authors: Khusaimi Zuraida , Mamat Mohamad Hafiz , Abdullah Norbani , Rusop Mohamad
Published: March 2013

Low-temperature solution immersion growth of low-dimensional ZnO nanostructures on gold-seeded Si substrate has been demonstrated. pH environment of the precursor solution, Zn(NO3)2.6H2O (zinc nitrate hexahydrate) and C6H12N4 (HMTA) was found to have considerable effect to ZnO morphology and photoluminescence. Structural, morphological and photoluminescence (PL) properties of the samples were obtained from XRD, SEM and PL-Raman characterisation. A near neutral (pH = 6.8) and acidic (pH = 5) precursor solution aided a dense near-aligned ZnO nanorods growth with smallest rods diameter of 30 and 20 nm respectively. Whereas alkaline precursor solution (pH = 9) gave rise to flower-like structures of ZnO. Chemical equations for the reactions and the role of H+ and OH- ions role in affecting the XRD diffraction peaks and morphology, are suggested. Room temperature PL emission spectra of ZnO were collected after excitation at 325 nm. UV and visible emission distinctive of ZnO were formed and the rationale for significant shifts of the visible emission was also discussed.
Ac Conductivity Study of Hexanoyl Chitosan-LiCF3SO3-EC-Al2O3 Nanocomposite Polymer Electrolytes
Authors: Winie Tan , Hanif Nur Shazlinda Muhammad , Rosli Nurul Hazwani Aminuddin , Subban Ri Hanum Yahaya
Published: March 2013

Films of hexanoyl chitosan-based polymer electrolyte were prepared by solution casting technique. LiCF3SO3, EC and Al2O3 were employed as the doping salt, plasticizer and filler, respectively. The ac conductivity of the electrolyte system under investigation has been studied in the frequency range from 100 Hz to 1 MHz over the temperature range from 273 K to 333 K. The exponent s in the Jonscher’s universal power law equation was analyzed as a function of temperature. The analysis suggests that the conduction mechanism for the nanocomposite electrolyte system can be interpreted based on the correlated barrier hopping (CBH) model. The ac parameters such as the barrier height, WM and cut-off hopping distance, Rmin were calculated. The values of WM and Rmin are found to decrease with increasing temperature in the same manner as the exponent s.
Preparation of Melamine Molecularly Imprinted Polymeric Microspheres by Two-Step Seed Swelling Polymerization
Authors: Qi Na , Chen Jun , Zhang Yu Ping , Zhang Yi Jun , Bai Lian Yang
Published: March 2013

Melamine molecularly imprinted polymeric microsphere (MIPM) was initially prepared by two-step seed swelling polymerization methods. Factors affecting the particle morphologies including emulsifier, dispersant, the water-oil ratio, and etc were optimized in order to obtain the MIPMs with a final narrow particle diameter of 3-5 μm. Characterization of the resulted polymeric microspheres was investigated by scanning electron microscope (SEM), infrared absorption spectroscopy (IR), and mercury analyzer (MA), respectively. When the initial concentration of melamine was 1.0 mmol L-1, the affinity capacity of MIPMs was 2.0 times than that of NIPMs. Scatchard analysis suggested melamine were recognized by the prepared MIPMs with two classes of binding sites. The apparent maximum binding capacity and dissociation constant were calculated to be 43.2 μmol g-1 (Qmax1) and 2.2×10-4 mol L-1 (Kd1) for high affinity site, whilst to be 102.3 μmol g-1 (Qmax2) and 1.3×10-3 mol L-1 (Kd2) for low affinity site, respectively. Obvious molecular effects towards melamine were further confirmed by the comparative HPLC experiments using NIPMs and MIPMs as the stationary phases, respectively.
Flotation Test Research on Refractory Copper Oxide Ore by Using Combined Activators
Authors: Wang Pu Rong , Dai Hui Xin , Gao Li Kun , Xu Guo Yin
Published: March 2013

The activation effects of single activator and some combined activators on Yunnan copper oxide ore were studied with Drawing a conclusion that the best activation - xanthate flotation result could be obtained by using sodium sulfide and ethylenediamine phosphate as the combined activator. on this basis, the open and closed circuit flotation tests were done , and in the closed circuit flotation test ,the flotation concentrate with yield of 5.90%, copper grade of 16.01% and recovery of 74.38% was obtained
Selection of Dehydration Temperature to Prepare Ammonium Polyphosphate with Crystalline Form V by Phosphoric Acid Process
Authors: Liu Gou Sheng , Liu Yue Long
Published: March 2013

Ammonium polyphosphate form V (APP-V) is prepared by melting phosphoric acid and melamine in ammonia atmosphere. The effect of dehydration temperature is studied by detailed investigation of the XRD patterns during the synthesis process. Results show that temperature higher than 3000C is suitable for preparation of APP-V. However, some impure other crystals are still coexisted in the synthesized product. The results are informative for controllable preparation of APP in industrial production
Effects of Compounding Addition of Sintering Aids on DC Bias Superposition Characteristic of NiCuZn Ferrites
Authors: Dong Li , Feng Ze Kun , Yan Shuo Qing
Published: March 2013

NiCuZn ferrites were prepared through conventional solid-state method. The effects of the sintering aids such as Bi2O3 and glass on the DC bias superposition characteristic of NiCuZn Ferrites were investigated. It was apparently discovered that when the glass and the Bi2O3 were doped together, the grain size was distributed consistently and the DC bias superposition characteristic reached an achievement comparing to the situation when the Bi2O3 and glass were doped alone. Additionally, it was also observed that the DC bias superposition characteristic had a significant relationship with Hc and △B.
Surface Modification of Coronary Stents for Intravascular Gene Delivery
Authors: Liu Lan Xia , Li Xiao Hong , Zhang Chao , Leng Xi Gang , Song Cun Xian
Published: March 2013

The present study investigated a novel surface modification on metal coronary stent for antibody immobilization. Methods: 316L stainless steel stents were surface modified with protein coatings. An Anti-DNA antibody was covalently bound to the protein surface using a bi-functional cross-linking agent SPDP. The artwork and binding stability of protein coatings were evaluated by in-vitro eluting. The feasibility and stability of anti-DNA antibody covalently bound to the stent were evaluated by means of 125I labeling. Results: We observed that pre-treating the steel surface using diluted HCL and increasing the ratio of cross-linking agent caused significantly increased binding stability of the protein coatings (p﹤0.001). The amount of chemically coupled antibody on the stents was 8 times higher than that of physically absorbed control stents. The stability of chemically coupled antibody on the stent was significantly better than physically absorbed control. Conclusion: It is concluded that we optimized the technique of protein coating on stainless steel and achieved stable anti-DNA antibody immobilization, therefore enabled efficient and highly localized non-viral gene delivery.
Preparation of Ag-TiO2@MnO2 and Degradation of Toxic Organic Pollutants under Visible Light Irradiation
Authors: Fang Yan Fen , Liu Jun Zi , Wang Shu Lian , Deng An Ping , Huang Ying Ping
Published: March 2013

Ag-TiO2@MnO2 nanoparticles prepared by two-step hydrothermal method were characterized by X-ray diffraction spectroscopy (XRD), transmission electron microscopy (TEM), Brunauer-Emmett- Teller (BET) and UV-Visible diffuse reflectance spectra (UV-Vis DRS). The degradation of rhodamine B (RhB) and 2, 4-dichlorophenol (2, 4-DCP) under visible light (λ≥420 nm) were used as probe reactions to investigate the photocatalytic activity of Ag-TiO2@MnO2. The results showed that the basic structure of Ag-TiO2@MnO2 was composed of TiO2 with anatase crystalline structure and α-MnO2 with cubic crysatalline structure. The optimal molar ratio nAg/nMn was 6%. Ag-TiO2@MnO2 had the highest photocatalytic activity in neutral medium because of composing and modifying of Ag. The decolorization rate of RhB reached 100% after 600 min and the mineralization rate of 2, 4-DCP was 47.0% after 30 hr. The oxidation process was dominated by the •OH generated in the system.
Preparation of Antibacterial WPU Nanometer Titanium Dioxide Composite
Authors: Zhou Shi , Zhou Bing , Huang Chun Ying , Chen Jia Jun
Published: March 2013

In the paper, WPU nanometer titanium dioxide composite is made mainly of polypropylene glycol (PPG), 2, 4-toluene diisocynate (TDI), nanometer titanium dioxide (TiO2), oleic acid (OA), dimethylolpropionic acid (DMPA), dibutyltin dilaurate (DBTDL), triethylamine (TEA), polypropylene glycol phosphate (PPG-P). Feature of nano particle is analyzed and tested by scanning electron microscope; Fourier infrared spectrum of nanoparticle and composite is tested by fourier infrared spectrometer under room temperature; thermal property test is conducted to composite by thermogravimetric analyzer; XRD test is conducted to nanoparticle and compound thin-film material by X-ray diffractometer; mechanical property of composite is tested by universal stretcher, proving that titanium dioxide does not change structure of WPU and titanium dioxide keeps the original crystal structure instead of being destroyed. Thermogravimetric analysis shows that titanium dioxide raises thermal stability of composite better; mechanical properties prove that increase of 2wt% nanometer titanium dioxide can raise mechanical properties of WPU. Titanium dioxide has extensive application prospect in production and life because it has optical activity and can raise antibiotic property of WPU.
The Study of the Simulation of Low Rigidity, Variable Cross-Section Shaft Electrolytic Grinding
Authors: Zhang Xue Juan , Yong Liu , Feng Xu
Published: March 2013

The very trajectory of electrolytic method of grinding process is suitable for processing high-precision, ultra-low rigidity variable cross-section of the shaft grinding new electrolytic process. On the basis of methods to the original trajectory of electrolysis in a grinding process, in this paper establishes the mechanical model of electrolytic grinding to finite element simulation analysis of electrolytic grinding shape error, by analyzing the factors affection the quality and the main factors of the electrolytic grinding force to. This research gets the rule that is between the grinding force and the shape error, and it also provides constraints for the future optimization of processing parameters.
Analysis of the Fracture for Transmission Output Shaft Based on ANSYS Workbench
Authors: Liu Zuo Shi , Han Lan Lan , Gao Xiu Qin
Published: March 2013

The static and dynamic of a certain type of manual transmission output shaft produced by a professional enterprise are analyzed. The results show that fatigue failure in four-speed condition and resonance in five-speed conditions are reasons of the fracture.
Study on the Automobile Exhaust Thermoelectric Generator Test Bench
Authors: Quan Rui , Tang Xin Feng , Quan Shu Hai
Published: March 2013

In order to utilize the exhaust heat of internal combustion engine effectively and enhance its fuel economy, a test bench used in Automobile Exhaust Thermoelectric Generator (AETEG) is designed in this paper, the main controller, temperature monitoring unit and single voltage monitoring unit of the control system are elaborated. Finally, several initial experiment results are provided, it reveals that prolonging the exhaust’s transmission time and path appropriately can help raise the temperature of heat exchanger’s surface and enhance the output performance of AETEG, the method adopted in this paper is feasible and the AETEG test bench designed is practical.
The Thermo-Mechanical Coupling Analysis of Disc Brakes Transient Temperature Field
Authors: Zhang Zhu Lin , Wang Zhi Ping , Dai Ru Quan
Published: March 2013

With the higher speed of the car, brake disc temperature will increase sharply when emergency braking, and its performance is demanded more and more higher. According to the Heat Conduction Theory, a brake disc's Thermo-mechanical Coupling model is built using ABAQUS software to analyze the brake disc transient temperature field. The analysis results shows that there is temperature gradient along the radial direction and axial direction, the temperature of the surface nodes with braking time has a wavy change, and the simulation result can be used as the references of brake disc design and selection.
Influence of Preheated Wire on GMAW Process
Authors: Ni Jun , Gao Hong Ming
Published: March 2013

An hot-wire GMAW process is proposed in which the wire is preheated by a TIG arc to enhance the wire melting, and the process is aimed at high efficiency welding with a low level heat input. The welding system is designed, the wire temperature is monitored and the metal transfer and arc behavior is observed. The preheating effect on the wire temperature is analyzed, and the influence of the hot wire on the metal transfer, arc behavior, and the weld formation are analyzed, compared with conventional GMAW. The results show that the preheated wire can significantly enhance the wire melting, and thus several beneficial effects on the GMAW process.
Static Coupling Analysis of a Six-Axis Force Sensor Based on Double Layer E-Type Membrane
Authors: Wang Zhi Hong , Xu De Zhang , Zhang Wan
Published: March 2013

The static coupling of a six-axis force/torque sensor is a major factor restricting its measuring accuracy. At present there is little literature quantitatively describing the coupling relationship in theory. This paper adopts an analytical modeling method to carry out the theoretical calculations for the deformation, stress and strain of the six-axis force/torque sensor based on double layer E-type membrane, and then analyze the static coupling relationship among dimensions on that basis.
The Effect of Specimen Orientation and Thickness on the Initiation of Delamination Crack in X80 Pipeline Steel
Authors: Liu Xiao Yu , Hu Tian Yi , Yang Zheng
Published: March 2013

The effect of weak interfacial orientation, thickness and the main crack depth on the initiation of delamination crack and main crack in three-point bending specimens of X80 pipeline steel are investigated, using 3D finite element method. Considering the different fracture mechanism of delamination crack and main crack, two different criteria are adopted for them in the simulation. The results reveal that, when the delamination cracks initiates, the initiating position is fixed and the Jz integral of the main crack is a constant for specific weak interfacial orientation specimens with different main crack depth and a certain thickness. When specific weak interfacial orientation specimens have different thickness and a certain main crack depth, the initiating position of delamination crack is equal to the above mentioned, but the Jz integral of the main crack has a ripad decline with the increasing of thickness and then tend to stable. In particular, the delamination crack will not appear for specimens with thin thickness. The thicker the specimen is, the higher the ultimate weak interface strength is needed to prevent the initiation of the delamination crack for specimen with a certain main crack depth. The larger delamination crack will generate, when the specimens have a lower ultimate weak interface strength, a smaller Jz integral of main crack and a larger thickness.
Research on Constitutive Model for Cartridge Case Materials
Authors: Zuo Hui , Sha Jin Long , Han Rui Guo , Liu Yi Hua
Published: March 2013

In order to simulate the rupture process of Cartridge Case, material failure constitutive model is researched. Johnson-Cook plasticity model is given as an analytical function of equivalent plastic strain, strain rate, stress triaxiality. Johnson-Cook plasticity model and Johnson-Cook Damage initiation criterion are used to describe the plastic deformation and fracture of case for the pressure of power gas. Using the implementation of this stress-displacement and characteristic length, problem of the relationship between fracture energy and the characteristic length in finite element model is solved. Finally, the simulated model which includes barrel, case, bolt and locking rigidity spring is built. Comparing the fracture shape and position in simulated test and physical experiment, the results are very similar. It proves that the rupture process of Cartridge Case can be simulated by the constitutive model which is introduced in this paper.
A Preliminary Research on Alkali-Activated Slag Concrete as Tunnel Lining in Severe Frigid Regions
Authors: Shu Heng
Published: March 2013

The main structure materials of tunnel lining are concrete and steel, and the concrete frost damage is a typical degradation phenomenon of the tunnel linings in cold regions. Alkali-activated slag concrete (ASC) has a better freeze-thaw resistance, which can be used for tunnel lining in severe frigid regions. Freeze-thaw resistance, performance mechanism of ASC and microstructure were investigated by freeze-thaw cycle, X-ray diffraction (XRD) and Scanning electron microscope (SEM) analysis. The experimental results show that, ASC has excellent freeze-thaw resistance, and hydration products of ASC are mostly C-S-H, alkaline aluminosilicate. ASC has a good compact degree and uniformity of structure, and its high compressive strength also makes high freeze-thaw resistance. ASC may be selected as tunnel lining production materials in severe frigid regions because of the less reduction in the dynamic elastic modulus and mass loss of concrete.
InAsSb Single Crystals and Photoconductors with Cutoff Wavelengths Longer than 8 µm
Authors: Gao Yu Zhu , Gong Xiu Ying , Makino Takamitsu , Kan Hirofumi , Wu Guang Hui , Feng Yan Bin , Koyama Tadanobu , Hayakawa Yasuhiro
Published: March 2013

High sensitivity uncooled InAsSb photoconductors with cutoff wavelengths longer than 8 mm were experimentally validated. The detectors were fabricated using InAs0.052Sb0.948 and InAs0.023Sb0.977 single crystals grown on InAs substrates by melt epitaxy (ME). The thickness of the epilayers was 50 mm. Ge optical lenses were set on the photoconductors. At room temperature, the photoresponse wavelength range was 2-10 m. Peak detectivity Dλp* (6.5 mm, 1200 Hz) reached 5.4 × 109 cm Hz1/2 W-1 for InAs0.052Sb0.948 immersed detectors. The detectivity D* was 9.3 × 108 and 1.3 × 108 cm Hz1/2 W-1 at the wavelength of 8 and 9 mm respectively. The good performances of InAsSb detectors indicate the possible detection applications
First Principle Study of the Optical Properties of Transition Metal Nitrides XN (X=Ti, Zr, Hf)
Authors: Wang Jin , Li Feng , Ao Jing , Zhong Ying , Chen Zhi Qian
Published: March 2013

The optical properties of face-centered cubic IVB group transition metal nitrides such as TiN, ZrN, and HfN were calculated using the plane wave pseudopotential method based on first-principle density function theory. The results of band structures show that conduction bands are mainly formed by the metal atom d-state, whereas valence bands are mainly formed by the N 2p-state. In optical properties research, the computed results of complex dielectric functions, absorptions, reflectivities, conductivities and loss functions of the three materials are analysed in terms of band structures. The results agree with experiment data. Analysis results show that the optical properties of these materials in low-energy regions are metallic because of the free electrons intraband-transition, and the transit to semiconducting properties in high-energy area is caused by valence electrons interband-transition. The sharp peaks of the transmissivity spectra indicate excellent optical selectivity in the visible light area. Moreover, lowering the starting energies of interband-transitions as a possible method to improve optical selectivities is discussed
Nano-HA Preparation and its Effects on Mechanical Properties of nHA/PLLA/PES Composite Biomaterials
Authors: Zhou Zhong Cheng , Shen Xiong Jun , Fan Xin , Wu Qiu Mei , Yang Hai Lin , Ruan Jian Ming
Published: March 2013

Nanocrystals hydroxyapatite (nHA) was synthesized and modified chemically, and nanocrystals hydroxyapatite / poly(L-lactide)/poly(ethylene succinate)(nHA/PLLA/PES) composite was prepared by melt-blending using nHA, PLLA and PES as reactants in a stainless steel chamber. The obtained nHA was of high purity and high crystallinity as well, its mean sizes measured from TEM observations were 65±35nm (long axis) and 40±10nm (short axis), and are close to the endosteal needle hydroxyapatite crystals size ((15 ~ 20) nm×60 nm) in the human body. The mechanical properties of nHA/ PLLA/PES blends were determined by bending and tensile tests and the effects of nHA content on the mechanical properties of nHA/PLLA/PES blends were investigated. The blending modulus and tensile modulus increase with the nHA (0,5,10,15and 20 wt.%) content increase, while blending strength increases up to HA mass fraction of 10% and after that decreases. SEM images revealed that the surface changed from rough to smooth with increasing nHA content, especially with nHA content higher than 20%, which implied the failure mechanism of the material changes from ductile to brittle.
The Formation Mechanism of Equiaxed Crystals in Pure Aluminum Solidification Structure under the Al-Ti-C Master Alloy
Authors: Ding Wan Wu , Zhao Wen Jun , Xia Tian Dong
Published: March 2013

The influence of different solidified velocities on the structure of pure aluminum during the process of refinement by Al-5Ti-0.6C master alloy was studied and the impact mechanism was discussed. The results show that at the same solidified velocity, with the increase of the amount of Al-5Ti-0.6C master alloy, in the solidified structure of pure aluminum, columnar crystals will gradually decrease, while equiaxed crystals will gradually increase. But in the case when the level of addition is the same, the faster the solidified velocity, the greater the number of equiaxed crystals will be in the ingot microstructure. The formation of equiaxed crystals is the result of the dual role of dissociation of crystal particles and heterogeneous nucleation of “TiC particle---Ti transition zone”.
Segregation Patterns and the Phase-Field 3D-Model for Adiabatic Phase Transition in Al-Cu Alloys
Authors: Ding Heng Min , Zhang Tie Qiao , Pu Lv Chun
Published: March 2013

In the paper, a model basing on solute conservative in every unit is developed for solving the solute diffusion equation during solidification. The model includes time-dependent calculations for temperature distribution, solute redistribution in the liquid and solid phases. Three-dimensional computations are performed for Al-Cu dendritic growth into an adiabatic and highly supersaturated liquid phase. A numerical algorithm was developed to explicitly track the sharp solid/liquid (S/L) interface on a fixed Cartesian grid. Three-dimensional mesoscopic calculations were performed to simulate the evolution of equiaxed dendritic morphologies.
Effects of Electrolyte Parameters on Properties of Ceramic Coatings Formed on Aluminum Alloy 7075 by Plasma Electrolytic Oxidation
Authors: Miao Jing Guo , Wu Run , Chen Qiu Rong , Hao Kang Da , Wei Zhong Ling
Published: March 2013

Four electrolyte (aluminate, silicate, borate and phosphate) solutions were optimized for using in surface treatment of 7075 aluminum alloy by plasma electrolytic oxidation. Microstructure, phase composition and corrosion resistance of ceramic coatings on the surface were analyzed by SEM, X-ray diffraction as well as electrochemical work station. It was showed that ceramic coatings prepared in aluminate solution had excellent continuity, compact structure with micro hardness of HV0.1 1100. The major portion of all coatings consisted of γ-Al2O3 and bits of α-Al2O3, the corrosion potential was increased by a small extent while the corrosion current density was significantly reduced.
Effects of Surface Oxide Coating on Corrosion Behavior of Ti-1023/LY12 Galvanic Couple
Authors: Shi Jun Xiu , Liu Jian Hua
Published: March 2013

Galvanic corrosion behavior of Ti-1023 titanium alloy coupled to LY12 aluminum alloy was investigated in 3.5% NaCl solution. Particular attention was given to the effect of anodized coatings on corrosion behaviors of Ti-1023/LY12 galvanic couple. Galvanic test was conducted on the following couples: Ti-1023/LY12, Ti-1023/anodized LY12 and anodized Ti-1023/anodized LY12, respectively. Corrosion properties including open circuit potential (Eoc) of each material, galvanic corrosion potential (Eg) and galvanic corrosion current (Ig) of the couples were monitored. Corrosion morphology was observed by optical microscope (OM) and corrosion mechanisms were analyzed and discussed. It was showed that anodized coatings significantly decreased Eg and Īg of the couples and provide effective protection of the anode from suffering corrosion attack. Only slight localized corrosion was detected on anodized LY12 alloy in the two anodized couples and the LY12 in anodized Ti-1023/anodized LY12 couple was found to be least susceptible to galvanic corrosion. The LY12 alloy in the bare couple: Ti-1023/LY12, was found to be highly susceptible to galvanic corrosion and suffered severe uniform and localized corrosion attack
Influence of Welding Sequence on Residual Stress and Distortion in Rectangular Welding of 6061 Aluminum Alloy
Authors: Jie Yi , Can Li , Sun Zhong Gang
Published: March 2013

This paper presented a detailed finite element simulation on the basis of elastic-plastic method combined with thermo-mechannical coupling algorithm，and the software abaqus was used for the welding simulation of thin-walled 6061-T6 aluminum. The residual stress and distortion with various types of welding sequence were investigated and the optimal welding sequence was gained through comparison and analysis. The results showed that the maximum residual stress on the plane of the welds was tensile stress after welding in a rectangular. The method of symmetry welding got smaller residual stress which could enhance the stability of the weldments, and starting from a longer welding path got smaller residual distortion of aluminum alloy.
Mechanism Analysis and Dairy Filtration Experimental Research on Porous 1Cr18Ni9 Stainless Steel Components
Authors: Dong Xiu Ping , Huang Ya Ting , Huang Ming Ji
Published: March 2013

Cool-drawn 1Cr18Ni9 stainless steel wires of 0.1~0.5 mm can be woven and punched to prepare porous metal filters. There is certain amount of connected micron pores in the transformable components. Filtration mechanism of this porous material is investigated and three series of samples with different diameter of wires, porosities and filtrating ranges are prepared. Filtration performances compares experiments are carried out on a kind of chocolate milk with the brand of Sanyuan. Three-dimensional microscopy, KEYENCE VHX-600, is applied to investigate the diaphragms before and after filtrating. Portable contamination analysis kit, HPCA-2, is chosen to identify the degree of contaminating. Results indicate that these kind of porous metal filters have valid solid/fluid separating effects. Wires diameters and other preparation parameters will identify the porosity. Thinner wires contribute to more and tinier porous and will block particles effectively. Thickness of filters plays the similar role of filtration layer. Higher porosity will increase the cleanliness of the passing fluid and decrease the filtering efficiency. The data in this paper provide technical support to the application in dairy filtration industry.
Quench Sensitivity and Quench-Induced Precipitation in High Strength 7xxx Series Aluminum Alloys
Authors: Li Zhi Hui , Xiong Bai Qing , Zhang Yon Gan , Li Xi Wu , Wang Feng , Liu Hong Wei
Published: March 2013

This paper investigates the quench sensitivity of some selected 7xxx series Al alloys based on a Jominy End Quench method. The precipitate microstructures as a function of cooling rate during quenching are also characterized by using transmission electron microscopy (TEM). The results indicated that quench sensitivity and therefore the mechanical properties inhomogeneity in large plates or forgings can be predicted more accurately by the simultaneous combination of hardness and electrical conductivity measurements based on Jominy end quench. The hardness drop and conductivity increase in the novel alloy following a low cooling rate are much reduced compared to AA7050 and 7B04 because of a lower sensitivity to quench-induced precipitation on dispersoids. The novel alloy exhibited the least quench sensitivity, and the 7B04 Al alloy was the most quench sensitive. If the 90% of the maximum hardness is defined as the depth of quenching, the depth of 7B04 Al alloy, AA7050 through Jominy end quenching is about 20 and 55 mm respectively. Meanwhile, the depth of greater than 150 mm is achievable in the novel alloy, and hence it can be recommended to fabricate large section plates or forgings without compromising properties in the center of the part after a slow cool.
The Determination of the Heat Release Rate on Cotton Smoldering Fire and Polyurethane Fire
Authors: Li Hong Wen , Yue Yun Tao , Li Yu Xing , Zhang Hao
Published: March 2013

This paper mainly introduces several common models of the heat release rate. The heat release rate of cotton smoldering fire SH2 and polyurethane plastic fire SH3 in the standard GB4715-2005 are determined according to the related data, and the result not only guide the way to study on the fire but provide the basis for setting fire reasonably in the numerical simulation.
A Study of the Best Extraction Technology of Nasal Mucosa Dosing Bromo Gels
Authors: Mao Li Chao , Zhang Shuang , Li Yuan Bing , Chen Jia Jun
Published: March 2013

In the paper, the best extraction technology of nasal mucosa dosing bromo gels is preferably selected. Orthogonal test is applied to screen the best technological condition for extracting nasal mucosa dosing bromo gels with content of ferulic acid and gastrodin as the indexes; it is figured out that the best technological condition is ethanol; the optimal technology is stable and feasible and can raise content of ferulic acid remarkably.
Prediction of the Slagging Characteristics of Coal Ash Based on Vague Sets
Authors: Wen Xiao Qiang , Sun Ling Fang
Published: March 2013

The distance measures of similarity between vague sets (values) have been developed to solve the problem of slagging characteristic of coal ash, and a slag-prediction model of coal ash based on vague sets was proposed. In the model, four single indices and their bounds are involved. The indices are ST, SiO2/Al2O3, B/A and G. At the same time, 25 coal ashes were selected as samples. the model was employed to predict the slagging characteristic of the 10 coal ashes. Through predicting, determining and comparison, it proved that the accuracy of the pattern recognition model was 90 percent and met the engineering requirements. So the model built was reasonable and feasible.
Study on New Industrial Briquette Composite Binder Using Response Surface Methodology
Authors: Zhao Wei , Li Yuan Cai , Tong Xing Lin
Published: March 2013

To develop a new industrial briquette composite binder, response surface methodology was used to arrange experiments, with modified peat(MP），mixed wastes(WS)，modified clay 2(C2) and clay 1(C1) as raw materials. The experimental data was firstly processed utilizing the method of multi-factorial total probability formula evaluation. Then based on the regression analysis and model building, the optimum formula was obtained. Finally, the bonding mechanism was analyzed through a systematical study by means of both ESEM and TG-DTA. The results indicated that the briquette prepared according to the optimum formula, namely 4.4% of MP, 6.5% of WS, 2% of C1, 1% of C2, and correlative key parameters of briquetting technics, namely forming water 13%, drying temperature 180°C and drying time 2.5h had excellent performances, which could meet the demand of industrial production in enterprises.
Study on Organic Modified of Montmorillonite by Corrosion Inhibitor of Quaternary Ammonium Salts
Authors: Sheng Jian Guo , Zeng Ping
Published: March 2013

A series of organic montomorilonite were prepared by using Sodium monanorilonite(Na-MMT) as raw material and quaternary ammonium salts with different chain long as intercalation agents by the way of ion exchange method. Weightlessness experiment showed that intercalated agents could alleviate the corrosion of metal. The MMT and organic MMT (OMMT) were identified by infrared spectra (FTIR) and X-ray diffraction (XRD). The results showed that intercalation agents had intercalated into the interlayer space of MMT, and the spacing of MMT layers had increased from 1.51 nm to 2.94 nm.
The pH Influence on the Preparation of Hollow Fe2O3 Spheres by Hydrothermal Method
Authors: Qiao Liang , Chen Jie , Jiang Li Qiang , Zheng Jing Wu
Published: March 2013

In this paper Fe2O3 precursor coating on the surface of carbon balls was prepared by hydrothermal method using Fe(NO3)3·9H20 and glucose as the raw materials. After calcination Fe2O3 hollow sphere could be achieved. The influence of pH value on the preparation of hollow Fe2O3 spheres was studied using XRD and SEM respectively. The results show that the pH value has no effect on the formation of Fe2O3 phase, but has a giant influence on the morphology of the hollow spheres. The Fe2O3 hollow spheres were achieved when the pH value was between 3 and 7. The particles with sheet and block structure form when pH7. The mechanism was studied, When 3
Research the Preparation of SiC/Al Composites by High Energy Ball Milling
Authors: Cai Xiao Lan , Li Zheng , Wang Qing Jun
Published: March 2013

High energy ball milling was used to preparation SiC/Al composites flakes. The research found the milling parameter of high energy milling was the ball/powder ration is 20:1, the rotary speed is 800 r/min, the milling time is 100min.Also researched the molding process of SiC/Al composites, the change of grain size and the weight fraction of the SiC, The research also found the mechanical properties of SiC/Al composites affected by the molding process. It was found that to reduce particle size and increasing of weight fraction of SiC, tensile strength of the SiC/Al composites increased. When the weight fraction of SiC in the SiC/Al composites is about 16%, the mechanical properties of SiC/Al composites about the hardness and tensile strength also get the high-point, the hardness and tensile strength is about 95HB and 248MPa.