bluuebunny/crossref_metadata_2025 huggingface dataset:
Biodegradability of Starch Based Films Blend with LLDPE and PVA
Authors: Bin Ab Aziz Mohd Farhan , Mohamed Rahmah
Published: September 2013

Biodegradability of films made from sago starch blend with PVA and LLDPE has been investigated. Blend films with different starch concentration were buried in the soil for 30 days for degradation test. FTIR and SEM have been performed on the film before and after degradation test to evaluate the biodegradability of the films. It was found that degradation rate increases with addition of starch into the blends.
Performance of Surface Modification of Polyvinylidene Fluoride Hollow Fiber Membrane in Membrane Distillation
Authors: Chong Kok Chung , Lai Soon Onn , Lee K.M. , Lau Woei Jye , Ooi B.S.
Published: September 2013

Membrane distillation (MD) is one of the novel separation methods used in water and wastewater treatment processes. MD is a thermal driven process which has the potential to be integrated with renewable energy source and can be operated at very low pressure. Polyvinylidene fluoride (PVDF) is a hydrophobic polymeric material which is commonly used to prepare MD membrane. In this study, surface modifying macromolecule (SMM) was added as additive into PVDF dope solution and then the hollow fiber membrane was prepared using phase inversion process. The membrane was characterized with respect to morphology and permeates flux at different temperatures. The results revealed that the PVDF membrane blended with SMM exhibited higher permeate flux than PVDF neat membrane did, mainly due to the better pore size distribution and thinner skin layer. This finding indicated the role of SMM in modifying the properties of PVDF membrane for MD process.
Structural Behaviour of Precast Lightweight Foamed Concrete Sandwich Panel (PLFP) with Double Shear Truss Connectors under Axial Load: Preliminary Result
Authors: Samsuddin S. , Ahmad I. , Goh W.I. , Mohamad N. , Samad Abdul Aziz Abdul , Rahman M.H.A.
Published: September 2013

This report provides experimental data on the development of PLFP for building construction. An innovative concept was used in the design of this system and the use of lightweight foamed concrete was discussed. Preliminary result of PLFP with double shear truss connectors was analysed and presented. PLFP was tested to determine its ultimate load carrying capacity under axial loading. Ultimate load carrying capacity, load deflection profile, surface strains and crack pattern were recorded and analysed. Test results were compared with calculated values based on classical formulas that developed by previous researchers and experimental data from previous researchers on its compositeness in between wythes. Results shown that PLFP with double shear truss connectors achieved higher compositeness in between wythes and have adequate ultimate load carrying capacity.
Effect of Buffer and pH on the Protein Extraction for Chicken Meat
Authors: Nahar M.K. , Zakaria Z. , Hashim U.
Published: September 2013

The study was undertaken to determine the extraction of proteins from chicken meat. The effect of buffer (phosphate, citrate and glycine) and four pH values (6.0, 7.0, 8.0 and 9.0) were investigated. The protein extractability of phosphate, citrate and glycine buffer with in the pH range (pH 6.0 to 9.0) was assessed to determine the best protein extractant for chicken meat. The maximum protein extractabilities at pH 8.0 for phosphate and citrate buffer, and at pH 9.0 for glycine buffer were observed. ANOVA analysis showed that there was no significant difference in protein extractabilities for citrate from phosphate and glycine buffer. Whereas, a significant difference was observed for phosphate buffer from glycine. However, no significant effects of pH were observed.
Effect pf Thermoplastic Polymer Waste (PET) in Lightweight Concrete
Authors: Daud M.A.M. , Selamat Mohd Zulkefli , Rivai A.
Published: September 2013

Contruction concrete that use of insulation wall in building construction faces some problems such as having high weight, very reflective sound, heat transfer (the effectiveness of heat conductivity) incompetence and mechanical properties (strength) constraints. The sounds which impinge the wall cannot be absorbed efficiently but instead gives high reflection. This causes some noise of high echo in a room. So a good acoustic insulation must be efficient in absorbing the sound. This project proposes lightweight concrete as a replacement for insulation wall. This lightweight concrete will be developed using thermoplastic polymer waste which is recycled plastic bottles, sand, water, and cement. This research used thermoplastic polymer waste which is PET (Polyethylene Terephthalate) material as the reinforcement material to replace small gravel in lightweight concrete. All its composition percentage of raw materials was divided into different samples composition. Its composition determines the performances of the samples in density, porosity and mechanical properties.
Thermal Properties of Different Recycled Acrylonitrile-Butadiene Rubber Glove (NBRr) Size and its Blend Ratios on SBR/NBRr Blends
Authors: Noimam N.Z. , Ismail H. , Mohd Salleh Mohd Arif Anuar , Al Bakri Abdullah Mohd Mustafa , Rosniza H.
Published: September 2013

The effects of SBR/NBRr blends on thermal properties of such thermal gravimetric analysis (TGA) and differential scanning calorimetry (DSC) were carried out. Results showed that by incorporating the smallest size NBRr provided more surface area to interact with SBR polymers thus increased the level of crosslink. TG thermograms shown by incorporating the smallest size NBRr in all ratios exhibit better thermal stability compared to large size NBRr. Due to many crosslinks formed with the incorporation of S1, hence at the end stage of degradation there were more cyclic and aromatic carbon formed during the rearrangement of the existing char. SBR/NBRr R05 with small particle sizes S3 and S2 showed similar crystallization temperature (Tc) at 37.1 °C. However by using S1, there was a conversion of Tc to heat capacity transition from high to low energy level at temperature 37.3 °C. Smaller size of NBRr showed better dispersion with SBR matrix hence the chances of crosslink form between SBR and NBRr is higher compared to using large size of NBRr.
The Properties of Recycled Copper Filled Epoxy/Unsaturated Polyester Composites
Authors: Phua J.L. , Teh P.L. , Supri A.G. , Yeoh C.K. , Ishak S.N.
Published: September 2013

A blend system between two different thermoset polymer, epoxy and unsaturated polyester at ratio 80/20 weight percentage (wt. %) with 10, 20, 30 and 40 volume percentage (vol. %) of recycled copper powder as conductive filler was investigated. The conductive polymer blend composites were undergone some characterization and testing which include flexural properties, hardness, thermal stability, electrical properties and scanning electron microscopy (SEM). The flexural strength of the unfilled system decreased as increasing of the recycled copper powder content. With the increase of recycled copper, from 0 vol.% to 40 vol.%, a total 350% of increment in flexural modulus was observed. The thermal stability of the blend polymer increased with the filler loading, from 140°C to 300°C, which was the 5% weight loss onset degradation temperature. The electrical conductivity properties of the blend composite shown the percolation threshold at 30 40 vol.% of recycled copper powder filler content, where the conductive blend composites change from insulator to conductor.
The Existing of Oxygen Nonstoichiometry in Complex Lithium Oxides
Authors: Idris Mohd Sobri
Published: September 2013

The possibility of oxygen deficiency in lithium-based complex oxides particularly for layered rock salt structures has little attention in the literature, in spite of the importance of these materials as potential lithium battery cathodes. This paper briefly reviewed the existing of oxygen non-stoichiometry in complex lithium oxides and their effect to perfomance of cathodes in lithium ion batteries.
High Temperature Creep and Hydrogen Embrittlement Failure of a Steam Trap Bypass Tube
Authors: Mohd Salleh Mohd Arif Anuar , Sebayang Darwin , Syahril D.I.C. , Sitompul Anton , Noriman N.Z. , Shamsudin Shaiful Rizam
Published: September 2013

A coal fired power plant with its normal operation temperature of 540oC in which its steam trap bypass tube in that power plant was totally fractured. The aim of this study is to explore the evidence related to the steam trap bypass tube failure and to determine the failure mechanism and the root cause of the failure and to give an appropriate recommendation. From the evidence with considering the contribution factors such as temperature, pressure and environment, a fault analysis was made and it can be concluded that the cause of failure to the steam trap bypass is due to multi causes which consists of creep failure and hydrogen damage.
Effect of Sintering Time on the Properties of LaYO3 Doped with ZrO2 Solid Electrolyte
Authors: Che Abdullah Salmie Suhana , Hazwani N.S. , Shafiqa N.A. , Wan Nordin Imaduddin Helmi
Published: September 2013

LaYO3 doped-ZrO2 ceramic with the composition La0.95Zr0.05YO3+δ was prepared via the solid state reaction. The samples were sintered at 1450 °C and sintering times in range of 6-15 hours have been varied for both doped and base samples in order to study its effect on its properties. The results showed that relative density increased remarkably with sintering time. The highest relative density was observed for the samples sintered for 15 hours. Scanning electron micrographs also proved that the porosity of the samples reduced when samples sintered for the longer time.
Electroless Ni-P-Cg(Graphite)-SiC Composite Coating on Cast AlSi Alloy
Authors: Mohtar M.M. , Ripin Z.M. , Ahmad Z.A.
Published: September 2013

The study presents the electroless N-P-Cg-SiC composite coating on cast AlSi (ADC12) alloy where the bath temperature is maintained at 90°C, pH level is controlled between 4.5 to 5.0 and stirred at 450 rpm with mechanical stirrer to avoid particles sedimentation. The increase of the coating film thickness is very insignificant after one hour of coating duration. This outcome is supposed to be due to inconsistent chemical concentration in the plating bath after this period. The nominal coating thickness of 39 μm is achieved after the substrate is immersed for 1 hour in four consecutive plating baths, respectively. The coating film is also successfully adhered to the substrate surface with the SiC and Cg particles are homogenously distributed.
Cure Characteristics and Hardness of Recycled Latex Catheter (LCr) Filled with Standard Malaysia Rubber (SMR L) Compounds
Authors: Ibrahim Lokman Hakim , Noriman N.Z. , Sam S.T. , Shahnaz S.A.B. , Ragunathan S.
Published: September 2013

The effect of cure characteristics and hardness of LCr filled SMR L compound were investigated. The size of LCr were 20 25 mm in range. Six compounds; 0, 5, 15, 25, 35 and 50 per hundred rubber (phr) of LCr were prepared by using two roll mill at room temperature. Cure characteristics such as scorch time,t2, cure time,t90, minimum torque, ML, maximum torque, MH, and cure rate index (CRI), and hardness of LCr filled SMR L were examined using rheometer. Result indicated that, all results for t2, t90, ML and MH shows the decrease with increasing in filler loading. CRI shows the increasing value with increasing LCr loading. Hardness, Ha value increase slightly with increasing LCr loading.
Effect of Compost Medium on Oxidative-Linear Low Density Polyethylene/Soya Powder Blends
Authors: Ting Sam Sung , Noriman N.Z. , Bakar Sharifah Shahnaz Syed , Nuradibah M.A. , Ismail H.
Published: September 2013

One alternative to enhance the degradability of polyethylene is the addition of prooxidant substances to their matix. The polymer materials are called oxo-biodegradable. Current investigation aimed to assess the abiotic degradation of linear low densit polyethylene (LLDPE), formulated with soya powder and cobalt stearate as prooxidant additives. The blends of LLDPE/soya powder are to improve the degradability of the materials. The samples with different blends ratio and fixed amount of cobalt stearate was buried into natural soil. It was found that the tensile strength and elongation at break of the eroded materials from the pro-oxidant activated samples were significantly lower than the control sample without cobalt stearate. These samples underwent biodegradation and gave weight loss values up to 9% over 6 months of soil burial. The blends with higher soya powder content shows higher degradation in compost medium.
Effect of Anodizing Voltage on the Growth Kinetics of Porous Anodic Alumina on Al-0.5 wt% Mn Alloys
Authors: Voon C.H. , Derman Mohd Nazree B. , Hashim U. , Ahmad K.R.
Published: September 2013

In this study, the effect of anodizing voltage on the current density versus time transient, oxide mass and the current efficiency of anodizing of aluminium manganese alloy was reported. It was found that the anodizing voltage facilitated the pore nucleation process and increased the steady state current density. However, when the anodizing voltage is 70V, dielectric breakdown occurred. The current density versus time transient for anodizing conducted at 30 to 60 V were typical while the shape was unusual for anodizing conducted at 70 V. The rate of oxide growth increased as a function of anodizing voltage. The current efficiency of anodizing increased as the anodizing increased from 30V to 70V.
Effect of Process Parameters on the Cooling Performance of Liquid Cooling System for Electronic Application
Authors: Arif Wan Mohd , Yeoh C.K. , Teh P.L. , Lim J.H. , Noorina Hidayu Jamil
Published: September 2013

This project is focused to study on the cooling performance of liquid cooling system under different process parameter. In this research, a liquid cooling system with copper block that simulates CPU, was setup to identify cooling performance of distilled water and vegetable oil at different mass flow rates (distilled water: 8.00g/s, 10.60g/s & 13.24g/s; vegetable oil: 1.22g/s, 1.30g/s & 1.38g/s) and input power (29.12W & 47.66W). The cooling performance of each fluid was characterized by the properties of: heat transfer coefficient, thermal resistance and also, the maximum CPU temperature (T4 at 66min) for the experiments. Experimental data shows that cooling performance was improved at higher mass flow rate and both distilled water and vegetable oil is a good coolant material.
Numerical Investigation of Heat Transfer of Twelve Plastic Leaded Chip Carrier (PLCC) by Using Computational Fluid Dynamic, FLUENTTM Software
Authors: Mazlan Mohamed , Rahim A. , Iqbal M.A. , Al Bakri Abdullah Mohd Mustafa , Razak W. , Nor Hakim H.M.
Published: September 2013

Plastic Leaded Chip Carrier (PLCC) package has been emerged a promising option to tackle the thermal management issue of micro-electronic devices. In the present study, three dimensional numerical analysis of heat and fluid flow through PLCC packages oriented in-line and mounted horizontally on a printed circuit board, is carried out using a commercial CFD code, FLUENTTM. The simulation is performed for 12 PLCC under different inlet velocities and chip powers. The contours of average junction temperatures are obtained for each package under different conditions. It is observed that the junction temperature of the packages decreases with increase in inlet velocity and increases with chip power. Moreover, the increase in package density significantly contributed to rise in temperature of chips. Thus the present simulation demonstrates that the chip density (the number of packages mounted on a given area), chip power and the coolant inlet velocity are strongly interconnected; hence their appropriate choice would be crucial.
Void Content Determination of Fiber Reinforced Polymers by Acid Digestion Method
Authors: Hassan M Hafiz , Othman Abdul Rahim , Kamaruddin S.
Published: September 2013

Porosity of the fiber-reinforced polymer (FRP) is one of very important quality characteristics for the advanced use of the material in order to ensure full performance properties are attained. It was found that the porosity values of FRP in typical aircraft composite parts must be lower than 2.5 % to achieve the required mechanical properties. The most common method for measuring the void content is through acid digestion testing or burn-off method, since it provides the true values that could be used to generate the database properties of the materials. Thus, this paper discussed the detail of the acid digestion test procedures for the void content measurement of FRP, especially with regards to the suitable testing time and chemical volumetric quantity required to ensure the matrix of test sample has been completely extracted. In order to attain this, different test samples for different processing techniques were prepared. Subsequently, the findings were discussed within the context of void content in cured monolithic composite for different types of process, in which the samples from the VBO-oven curing process were compared with those of the autoclave-cured samples. In the VBO-oven curing process, the use of an intensifier during the curing provided higher void content of 15.52% in comparison with those achieved through the debulking process (10.91%). It has been clearly observed that the debulking produced a substantial effect towards the air evacuation mechanism within the laminate.
Current Trend in Simulation: A Study Simulation of Poly-Silicon Nanowire Using COMSOL Multiphysics
Authors: Hashim U. , Wesam Al-Mufti M. , Adam Tijjani
Published: September 2013

Poly-Silicon nanowire (Poly-Si-NW) simulations are very important field of nanotechnology and nanostructures; in this paper presented review in general nanowire and it applications such as thermoelectric device (TED) has potential applications in areas such as chip level cooling/ energy harvesting and many more applications in this field .COMSOL multiphysics is one of programmers using for nanotechnology and nanowires simulation, hence in this review paper, COMSOL simulation with different types of materials using for nanowire and other structures. Also In this work, we explore the effect of the electrical contact resistance on the performance of a TED. COMSOL simulations are performed on Poly-SiNW to investigate such effects on its cooling performance. Intrinsically, Poly-SiNW individually without the unwanted parasitic effect has excellent cooling power density. However, the cooling effect is undermined with the contribution of the electrical contact resistance.
Green Bricks from Waste
Authors: Shakir Alaa.A. , Naganathan Sivakumar , Mustapha Kamal Nasharuddin Bin
Published: September 2013

This paper presents the findings on an investigation done on the use of Quarry dust, Fly ash and Billet scale in developing bricks. Bricks were made with various proportions of those materials and cement. Tests for fresh density, compressive strength, and water absorption were conducted. The compressive strength of bricks ranged from (7.2-26.3) MPa, the water absorption fell in range between (13-14.26) %. The optimum ratio of Fly ash and Billet scale is 1:1. It is shown that bricks with enhanced properties can be developed using these industrial wastes.
Effect of Milling Time on Particle Size and Surface Morphology of Commercial Zeolite by Planetary Ball Mill
Authors: Mukhtar N.Z.F. , Borhan M.Z. , Rusop Mohamad , Abdullah Saifollah
Published: September 2013

Ball milling is a top down approach and a method to reduce size of particle while Zeolite is a valuable inorganic materials having wide variety of applications. In this paper, ball milling of commercial synthetic Zeolite powder was studied with their time varied. Wet ball milling was selected as a potential means to decrease the particle size of Zeolite over dry grinding. The parameters that included in this study were rotational speed, balls to powder ratio, water to powder ratio and milling time. These nanozeolite were characterized via Zeta-sizer nanoseries of particle sizer, FESEM, and also FTIR. Results showed that commercial synthetic Zeolite powder with particle size larger than 45 μm may be reduced into the size range between 0.2 0.3 μm by planetary ball mill.
Mechanical Properties of Dissimilar Welds between Stainless Steel and Mild Steel
Authors: Jamaludin Shamsul Baharin , Mazlee Mohd Noor , Kadir Shahzan Kamarul A. , Ahmad Khairel Rafezi
Published: September 2013

Joining of stainless steel type 304 to mild steel was carried out using a gas tungsten arc welding (GTAW). Samples were welded using stainless steel welding electrode: (AWS: E308l-16) and mild steel welding electrode: (AWS: E6013). The mechanical properties of welded joint were investigated by tension test. It was observed that, the yield strength and tensile strength of welded samples using mild steel welding electrode were slightly lower than welded samples using stainless steel welding electrode. All welded samples fractured at mild steel base metal indicated that the regions of stainless steel base metal, fusion zone and heat affected zone are stronger than mild steel base metal.
Simulation of Glass Molding Process for Planar Type SOFC Sealing Devices
Authors: Lin Huey Jiuan , Hsu Fu Yuan , Chiu Chun Yu , Liu Chien Kuo , Lee Ruey Yi
Published: September 2013

The glass sealant with pre-forming frame structure, used for joining dissimilar materials of planar type SOFC devices, was fabricated by molding process. The flow phenomena during glass molding were investigated by computational modeling. The physical properties of glass sealant fluid were constructed in numerical models. The process parameters, such as mold pressing velocity, initial glass fluid temperature (or viscosity of glass sealant), and initial mold temperature, were examined. As results, the sealants formability could be characterized by molten glass temperature, near the gap between upper and lower molds. If the temperature is greater than its glass transformation temperature Tg, the formability become better, and vice versa.
Keywords: solid oxide fuel cells (SOFCs), computational modeling, glass sealant.
Surface Tension Measurement of Liquid Fe-Si-B Alloy by Sessile Drop Method
Authors: Chao Kuo Lin , Lian Shuang Shii , Wu Chung Yung , Chang Ku Ling
Published: September 2013

The purpose of this study is to measure contact angle and surface tension of liquid Fe-Si-B alloys at high temperature using sessile drop method. The surface tension and contact angle result is based on sessile drop method by use of a digital camera to take the drop profile and fit the profile by Youngs-Laplace equation. The surface tension of liquid Fe-Si-B alloy and its dependence on temperature has been studied. Contact angles of this liquid alloy on various refractories substrate have been determined using this instrument. The result showed that the contact angles and surface tension of Fe-4Si-3B alloy liquid drop on Al2O3 substrate have value of 134 to 127and 1575-1350 mN/m respectively. The result indicated also that increasing temperature can decrease contact angle and surface tension in Fe-Si-B alloy.
Cracking Control for Diaphragm of Long-Span Prestressed Concrete Box Girder Bridge at the Early Age
Authors: Li Guo Dong , Wang Zong Lin
Published: September 2013

This paper presents the results of a study on the early-age cracking behavior of diaphragm in long-span prestressed concrete box girder bridge with cracking control techniques. Based on the three-dimensional hydration heat temperature conduction and humidity diffusion theory, and according to the similarity of differential equation between the humidity diffusion theory and temperature conduction theory, the early-age cracking of diaphragm was simulated by a three-dimensional finite element model with consideration of concrete shrinkage, creep, cement hydration heat and variation of temperature. The numerical simulation accurately predicts the cracking region and size and stress time history of diaphragm, and provides load standard for cracking control techniques of prestressing force. The cracking control techniques of prestressing force effectively avoid the early-age cracking of diaphragm by application of practical engineering.
Review of the Application of Finite Element Model Updating to Civil Structures
Authors: Wang De Jun , Tan Zhi Cheng , Li Yang , Liu Yang
Published: September 2013

Structural finite element model (FEM) updating in dynamics usually deemed the measured modal parameters as the goal. By modifying the theoretical FEM, the updated modal parameters obtained by the analytical FEM would finally tend to the testing results. But the own complexity of the civil structure leads the optimization problem of FEM updating to be super-size and high non-linear performance. Moreover, the uncertainty and nonuniformity of the structures, material and the environment effect cause the uncertainty of the updating parameters, even the optimization objective function of FEM updating. These features has brought greater difficulty to the model updating in civil engineering structure, especially for the application field. Therefore, in this paper several kinds of methods for FEM updating would be introduced with the comparison of their advantages, disadvantages and the range of application. At the end of this paper, the problems remained to be solved in FEM updating of civil structures are to be presented.
Safety Assessment of Slant Legged Rigid Frame Bridge Based on Field Testing
Authors: Li Yan , Bi Hong Tao , Li Bing Han , Wang Yong Jun
Published: September 2013

The safety and load-bearing capacity of an in-service urban reinforced concrete slant leg rigid frame bridge over railway is assessed by field testing and finite element analysis. The bridge is located in Qitaihe city, the northeastern of China. The two heavy trucks and three different loading test configurations are used in experiment. The three load figuration is set up and performed based on the result of technical condition investigation and finite element numerical analysis. The vertical displacement and key section strain response are recorded during experiment. Loading-bearing capacity and safety performance of the bridge is analyzed and evaluated according to measured data combining with numerical analysis. The testing result shows that structural stiffness and strength of the bridge do not satisfy the requirements of the original design. Based on the assessment result, some proposals are proposed to the management office. A moderate maintenance and reinforcement treatment should be carried out for this bridge to improve the bearing capacity and ensure safety operation. Before that completed some traffic control measures should be taken to avoid aggravating diseases and damages of the bridge due to passing heavy vehicle.
The Ratio Optimization of Side to Main Span in Low-Pylon Cable-Stayed Bridge Based on Yudao River Bridge
Authors: Bi Hong Tao , Li Yan
Published: September 2013

This paper presents an optimization model for investigating the influence on the ratio of side to main span in low-pylon cable-stayed bridge. Based on the structural analysis theory of cable-stayed bridge and combined with engineering practical, the optimization model considered that adjusting structural internal force by means of changing the side span length. Comparing and analyzing the optimization index in the result, the reasonable ratio of side to main span to this kind of bridge can be getting.
The Constitutive Model and Processing Map for In Situ 5wt% TiB2 Reinforced 7050 Al Alloy Matrix Composite
Authors: Wang Ming Liang , Chen Zhe , Chen Dong , Wu Yi , Li Xian Feng , Ma Nai Heng , Wang Hao Wei
Published: September 2013

This study investigated the constitutive flow behavior and hot workability of in-situ 5wt% TiB2 reinforced 7050 Al alloy matrix composite by hot compression experiments. Based on the experimental results of flow curves, a constitutive model describing the relationship of the flow stress, true strain, strain rate and temperature is proposed. Substantially, it is found the constitutive equation of flow stress is dependent on the strain, strain rate and temperature. The coefficients (E.g., α, n, Q and lnA) in the equation are functions of true strains. The results of the calculated values from constitutive equation are verified to well agree with the experimental values. Furthermore, the processing map of the composite is created in order to determine the hot processing domains. The optimum zones for hot workability and instability regions are identified. In instability domain, the microstructures display the main failure modes as the particle cracking and interface debonding.
Formation and Mechanical Properties of Instrument Panel Skins Produced by PVC Powder Slush Molding Processes
Authors: Wang Fei , Chen Juan , Yao Wei Guo , Sun Jun , Yu Shan Ping , Wen Xiang Yang , Jia Yu Xi
Published: September 2013

The compositions of PVC slush powder are determined by means of gel permeation chromatography (GPC) and pyrolysis gas chromatography/mass spectrometry (PGC-MS) methods after its separation and purification. The melt and combination of the powder during the formation processes of the slush molded skins are observed by polarizing microscope experiments. Dynamic mechanical analysis (DMA), stress relaxation experiments and Haward model are then used to study the physical and mechanical properties of the skin. It is found that the powder contains abundant phthalate and trimellitate plasticizers because of which the glass transition temperature Tg of the skin is quite low. There is a critical temperature above which the melt and combination of the powder accelerate. Stress relaxation experiments can eliminate the interference of viscous force. Based on that, the network structure of the skin and its Gaussian modulus can be well represented by Haward model.
The Research Progress of the In Situ Metal Matrix Composites
Authors: Jiao Lei , Zhao Yu Tao , Wang Xiao Lu , Wu Yue , Yang Song Nan , Li Kai Nian
Published: September 2013

This paper reviewed the current situation and process of research on in-situ metal matrix composites. Compounding mechanisms, fabricating techniques and main features of metal matrix composites were respectively analyzed. At the same time, the properties of different kinds of in-situ metal matrix composites were briefly introduced. Meanwhile, the problems in the in-situ fabricating techniques and future prospects were also discussed.
A Self-Repair Mode for Capillary Reinforced Polymer Composite
Authors: Yuan Xin Hua , Wu Ji Ye , Liu Yong Qiang , Mao Jun Xia , Ou Xue Tao , Han Zhi Rui , Jiang Xiao
Published: September 2013

The paper describes a novel capillary reinforced plastic which can self-repair the impact damage in polymer composites through employing a bio-mimetic approach. A epoxy resin E-51 and harder WSR706# was used as the healing agent, the two components being filled in to different directions (0°and 90° fibers). Impact test and tensile test were used as a measure of the self-healing effectiveness. The results of flexural testing have shown that strength lost after impact damage can be restored by the self-healing effect with healing agent stored in capillaries, and a significant fraction (about 79%) of lost mechanical strength is restored by this effect. At the same time, the paper also studied the morphology of fracture surface of no embedded and capillaries embedded sample. And micrographs of crack morphology which has been healed have been observed.
Fabrication & Microstructure of TiB2+TiC Duplex Particulates Reinforced Carbon Steel Matrix Surface Composite
Authors: Guo Chang Qing
Published: September 2013

This paper presents a novel fabrication process that combines SHS with V-EPC (vacuum expandable pattern casting) and microstructural features of TiB2+TiC duplex particulates reinforced surface composite with carbon steel matrix. Macro structural observation shows that the surface composite is dense and there are no obvious defects. Microstructural investigation demonstrates that the composite from surface to core is consisted of three different layers, i.e., the top surface compound layer, the interim transitional layer and the bottom carbon steel matrix. A large amount of fine TiB2 and TiC duplex particles are evenly distributed in the composite matrix, while the concentration are significantly decreased and non-uniform distribution increased for these particles in the interim layer.
Effects of Annealing on Microstructure and Mechanical Properties of Backward Extruded Mg-0.5Mn-1Nd Alloy
Authors: Ma Ning , Peng Qiu Ming , Li Hui , Pan Jun Ling
Published: September 2013

Mg-0.5Mn-1Nd (wt.%) alloy has been prepared by zone purifying method followed by backward extrusion (BE) technique. The microstructures, recrystallization behavior from 150 to 400 °C and mechanical properties of Mg-0.5Mn-1Nd alloy were investigated. The alloy exhibited bimodal microstructures after BE deformation. The equiaxed grains changed to more homogeneous after annealing treatment in range of 150 to 250 °C. The similar trend was confirmed after thermal annealing treatment at different annealing temperatures. The abnormal grains growth was clearly observed when the temperature was higher than 350 °C. Compared with BE-Mg-0.5Mn-1Nd alloy, both yield strength and ultimate tensile strength were reduced after annealing treatment, whereas the elongation was increased correspondingly. These results were mostly related to the fine grain size and homogeneous secondary precipitate.
Ultra-High-Strength Concrete-Filled FRP Tubes: Compression Tests on Square and Rectangular Columns
Authors: Ozbakkloglu Togay
Published: September 2013

This paper presents the partial results of an experimental program undertaken to investigate the behavior of square and rectangular ultra-high-strength concrete (UHSC)-filled fiber reinforced polymer (FRP) tubes (UHSCFFTs) under axial compression. The effects of the amount of confinement, cross-sectional aspect ratio and corner radius were investigated experimentally through the tests of 24 concrete-filled FRP tubes (CFFTs) that were manufactured using unidirectional carbon fiber sheets and UHSC with 108 MPa average compressive strength. Test results indicate that sufficiently confined square and rectangular UHSCFFTs can exhibit highly ductile behavior. The results also indicate that HSCFFTs having tubes of low confinement effectiveness may experience a significant strength loss at the point of transition on their stress-strain curves. Examination of the test results have led to a number of important observations on the influence of corner radius and sectional aspect ratio, which are presented and discussed in the paper.
The Influence of Top Layer on ZnO/Cu2S/ZnO Films in Optoelectric and Photocatalytic Performance
Authors: Xu Feng , Sun Sheng Nan , Wang Yi Xin , Bian Feng Ling , Wang He , Fu Zhen Xiao , Wang Hai Shui , Cui Hai Ning
Published: September 2013

In this paper, the ZnO/Cu2S/ZnO complex films were fabricated by Radio Frequency (RF) magnetron sputtering, and their transparent, conductive and photocatalytic properties have been investigated. The results show the properties of ZnO/Cu2S/ZnO complex films vary when the top layer ZnO thickness changes.
Research on the Properties of Composite Portland Cement with High Volume of Industry Waste
Authors: Du Bao Li , Fu Xing Hua , Tao Wen Hong , Jin Xin
Published: September 2013

The paper studied the influences of some industry wastes on the properties of composite Portland cement. Different amount of wastes were added as cement mixture. Through the investigation of properties of cement by orthogonal experiments, the optimum combination was obtained. The hydration products were analyzed by XRD and SEM. Its hydration mechanism was investigated and the result shows that with appropriate ration of each influencing factors, the cement could meet the national standard 42.5MPa of cement strength.
Analysis and Simulation of a Hybrid Mechanism with 2R-3T of Special Machining Platform
Authors: Yang Qi Zhi , Yao Bin Bin , Cao Dian Feng
Published: September 2013

This paper designs a platform which is used for material pose alignment of complex curved surface parts laser processing. The parallel platform is based on a hybrid mechanism with five spatial degrees of freedom. The mechanism is built up by three parallel vertical chains {(P-R-C), (C-R-C-R), (P-H)} and two series single opened chains {(P), (P)}. This processing platform is an ideal hybrid platform with 2R-3T, and it has the advantages of both the parallel mechanism and the series mechanism. The DOF (degree of freedom) of the parallel mechanism is calculated and the positions of the moving platform are analyzed. The results of the position-equations are simulated by using ADAMS software. It is shown that the processing platform is able to meet the requirements of any angle positions of various materials processing, and realize material special machining.
Compare the Fluxing Effect of Boron Sludge and CaF2 on CaO-Based Steelmaking Slag
Authors: Wang Hong Ming , Zhu Xiang , Li Gui Rong , Yang Li Li , Peng Cong Xiang , Qu Chang Chen
Published: September 2013

To reduce the pollution caused by employing CaF2 as fluxing agent in metallurgical flux, boron sludge is used as fluxing agent to substitute for CaF2. The melting temperatures of CaO-SiO2-Fe2O3-boron sludge system were investigated. The melting temperature of CaO-SiO2-Fe2O3-boron sludge slag system is increased with the increase of ω (CaO)/ω (SiO2) at first, and then fluctuates at about 1430°C. Moreover, the melting temperature of CaO-SiO2-Fe2O3-boron sludge system is decreased with the increase of boron sludge content at first and then increased, 7% content of boron sludge has the best fluxing effect and the melting temperature is1445°C. As a conclusion, the fluxing effect of boron sludge is close to CaF2, boron sludge may be considered to substitute for CaF2.
Effect of Fiber Coating on Properties of Ni-MF/Al2O3 Composites
Authors: Liu Lu Hao , Wang Zhi , Shi Guo Pu , Ma Yan , Feng Shu Ai , Wu Chao
Published: September 2013

By adding sintering additives (CMS and nanoTiO2), Ni-MF/Al2O3 composites were prepared by pressureless sintering. In order to ameliorate the combination between mullite fiber and alumina matrix, mullite fiber surface was coated with Al2O3 coating. To improve the property of alumina ceramic composite, Ni particles were chosen as toughening phase. For the preparation of composite, the optimum process was 10% MF, 13% Ni, and sintering temperature in 1400°C. The material performance can be effectively improved.
Influence of Compound Bonding Agent on the Performance and the Microstructure of Proppant
Authors: Sun Jie Jing , Qin Lu Lu , Song Xue Hua
Published: September 2013

Low-density proppants have been developed using two kinds of bauxites containing different ratios of aluminum as main raw materials and compound liquid as a binding agent. The influences of the amount of compound bonding agent and the sintering temperature on the performance of the proppant were studied. The phase composition of calcined sample was identified by X-ray diffraction (XRD) method. The microstructure of the sintered sample was characterized by scanning electron microscope (SEM). It is shown that the proppant prepared with increasing compound bonding agent can meet the national standard. With the increase of the sintering temperature, mullite with uniform grain size is formed.
Finite Element Simulation and Experimental Study on Isothermal Forging Technology for a Complex-Shaped Titanium Alloy Wing
Authors: Cheng Feng , Jiang Hong Yan
Published: September 2013

A closed isothermal forging process was adopted for precision forming of the Ti-6Al-4V wing with a variable cross-section asymmetric structure. Firstly, simulations under different process parameters, such as the deformation temperature, punchs velocity et al. were analyzed with DEFORM-3D software to eliminate the defects in the isothermal forming process. The simulation results demonstrated that the loads during isothermal deformation were determined not just by the forging temperature but the punchs velocity, the less velocity of punch, the better filling ability, and yet temperatures from 900 to 950°C had less influence on filling ability. To verify the validity of simulation results, the isothermal forging experiment was carried out on an isothermal forging hydraulic press (THP10-630). It is demonstrated that the optimized billet dimension can ensure the quality of forging part and the titanium alloy wing component with complex shape was successfully forged with the punch speed of 0.1mm/s at 950°C and its mechanical performances were improved.
Study of the Impact Abrasive Wear of New Super-High Manganese Steel
Authors: Wang Wen Yan , Xu Jian , Xie Jing Pei
Published: September 2013

Based on the traditional Mn13, the super-high manganese steel Mn18 was melted by means of adjusting the amount of C, Mn, adding a certain amount of alloying elements Cr, Mo etc and modification. The results show that with low-impact energy abrasive wear for 60 minutes, the wear resistance of super-high manganese steel Mn18 was greatly improved by contrast with that of Mn13, and the hardness of wear surface was increased slowly with the elapse of the wear time. However, under the high impact energy, the wear resistance of Mn18 is 1.5 times as high as that of Mn13, and the hardness of wear surface was increased to HB440 in a short time. The main wear forms were: cutting, gouging wear and plastic deformation. Typical TEM morphologies of subsurface wear structure consist mostly of high density dislocations, deformation bands.
Laboratory Research on Energy Harvesting of Ionic Polymer Metal Composite
Authors: Kwaśniewski Janusz , Dominik Ireneusz , Kaszuba Filip
Published: September 2013

The aim of this paper is to present the results of laboratory research on Ionic Polymer-Metal Composite (IPMC), in context of energy harvesting applications. IPMC is a novel type of material, a smart polymer, which can work as a sensor or an actuator. One of its biggest advantages is low actuating voltage of about 4V (with 120mA current), what makes it very energy-efficient. Step response for various input amplitudes of two IPMC samples is shown. Also, a voltage generated in response to mechanical deformation of the composite is measured, and a hysteresis loop is plotted. Lastly, the changes of properties of the IPMC caused by long-term actuation are researched. These results are necessary to build an energy harvesting system utilizing IPMC. A simple gripper built with IPMC is also presented.
Experimental Tests of an Electromechanical Transducer of Reverse Linear Motion into Electrical Energy
Authors: Węgrzynowski Marcin , Romaszko Mateusz
Published: September 2013

This document deals with the results of laboratory tests of an experimental electromechanical transducer for supplying an magnetorheological (MR) damper. The aim of the tests was to determine: the electromotive force induced in the sectionalized coil, the voltage and the current strength in the control coil of the damper as well as instantaneous power. The results provided are based on the tests of the transducer under periodic kinematic excitations and are compared with those achieved in numerical calculations.
A Pilot Study of Pepsin in Tracheal and Oral Secretions
Authors: Schallom Marilyn , Tricomi Sally M. , Chang Yie-Hwa , Metheny Norma A.
Published: September 2013

Background

Because reflux of gastric juice into the oropharynx must precede its aspiration into the lungs, it is reasonable to hypothesize that the detection of pepsin (the major gastric enzyme in gastric juice) in oral secretions may provide a relatively noninvasive method of predicting risk for aspiration.

Objective

To describe the incidence of pepsin in oral and tracheal secretions collected concurrently from a sample of 50 gastric-fed patients undergoing mechanical ventilation.

Methods

An exploratory descriptive design with a convenience sample from 4 medical and surgical intensive care units. An oral secretion and a tracheal secretion were collected concurrently from each patient (yielding a sample of 50 oral and 50 tracheal secretions). The tracheal secretions were obtained via the inline suction system with an attached sputum trap; oral secretions were obtained via a Yankauer suction tip with an attached sputum trap. All specimens were assayed for pepsin by the Western blot method.

Results

Oral secretions from 10 patients (20%) and tracheal secretions from 2 patients (4%) were pepsin-positive. Both patients with pepsin-positive tracheal secretions also had pepsin-positive oral secretions. Pepsin was not found in the tracheal secretions from the remaining 8 patients with pepsin-positive oral secretions.

Conclusions

Although reflux of gastric juice into the oropharynx must precede its aspiration into the lungs, individual reflux events do not necessarily lead to aspiration. Thus, it is reasonable that we found pepsin 5 times more often in oral secretions than in tracheal secretions.
Invasive Aspergillosis Masquerading as Catastrophic Antiphospholipid Syndrome
Authors: Robinett Kathryn S. , Weiler Bethany , Verceles Avelino C.
Published: September 2013

A 25-year-old woman with a history of systemic lupus erythematosus who was taking steroids came to the hospital because of vague signs and symptoms of weight loss, constipation, and oral ulcers. Multiorgan dysfunction developed, and catastrophic antiphospholipid syndrome was suspected. She was treated with an intravenous infusion of heparin, but she experienced a subdural hemorrhage and died on day 10 of the hospitalization. An autopsy revealed disseminated invasive aspergillosis. This case illustrates that invasive aspergillosis is a frequently missed diagnosis and should be part of the differential diagnosis for any patient who is immunosuppressed, including patients with autoimmune diseases such as systemic lupus erythematosus.
Patterns of Opiate, Benzodiazepine, and Antipsychotic Drug Dosing in Older Patients in a Medical Intensive Care Unit
Authors: Pisani Margaret A. , Bramley Kyle , Vest Michael T. , Akgün Kathleen M. , Araujo Katy L.B. , Murphy Terrence E.
Published: September 2013

Background

Anecdotal observation suggests that older patients in medical intensive care units receive higher doses of psychoactive medications during evening shifts than day and night shifts.

Objectives

To determine the dosing patterns and total doses of fentanyl, lorazepam, and haloperidol according to nursing shift in a cohort of older patients in a medical intensive care unit.

Methods

The sample consisted of 309 patients 60 years and older admitted to the medical intensive care unit at Yale-New Haven Hospital, New Haven, Connecticut. Data on time, dosage, and route of administration of the drugs were collected. Data were analyzed by using a Bayesian random effects Poisson model adjusted for individual heterogeneity, excess zero doses, and important clinical covariates.

Results

Mean age of the patients was 75 years; 58% received fentanyl, 55% received lorazepam, and 32% received haloperidol. Although dosing with fentanyl did not differ according to shift, doses of both lorazepam and haloperidol were higher during the evening shifts (4 pm to midnight) than during the day or night shifts. Compared with women, men received higher doses of both haloperidol and lorazepam and variability between shifts was greater.

Conclusions

In this longitudinal, observational sample of older patients, data indicated a positive association between dose levels of lorazepam and haloperidol during the evening nursing shifts relative to other shifts. Further investigation is needed to determine potential causes and to evaluate the impact on outcomes of sleep deprivation and delirium.