bluuebunny/crossref_metadata_2025 huggingface dataset:
Estimate Soil Organic Matter Content in the Heihe River Basin Using Hyperspectral Method
Authors: Li Hai Ying , Peng Hong Chun
Published: February 2012

.Soil properties are very absent and sorely needed for many models. Conventional measurements are expensive and many samples are required. Hence it is difficult to quantitatively analysis them at a large-scale region. Hyperspectral methods are now used for the rapid characterization of a wide range of soil. In this paper, it was used to estimate organic matter content in soil of Heihe River basin. A total of 84 samples were collected and their reflected spectral were measured with ASD spectrometers. Then the organic matter were predicted using four forms of spectra and PLS method. The results show:1) the hyperspectral remote sensing can be used to predict soil organic matter content, and the precision can meet the requirement; 2) the best region of spectrum is 400~800nm in R, 1/R and Log (1/R) formation, and the FDR and FD(Log (1/R)) centered in 800nm based on the correlation coefficient and Variable Importance in Projection.
Structure and Properties of Cobaltous Chloride/Polyvinyl Alcohol-Glutaraldehyde(CC/PVA-GA) Reversible Thermochromic Microcapsule
Authors: Gao Jie , Guan Ping , Hu Xiao Ling , Cao Mei
Published: February 2012

The low-temperature reversible thermochromic microcapsules was prepared by interfacial polymerization, which an aqueous phase containing CoCl2 was used as the internal water phase (W1), cyclohexane was used as the oil phase (O), polyvinyl alcohol was used as the external water phase (W2) to form the uniform W1/O/W2 multiple emulsion. The structures of microcapsules were investigated using infrared spectrum (IR), electron microscopy (SEM) and polarization microscope. The properties of microcapsules, such as thermochromism and solvent resistance were also investigated. The results presented that the particle size of capsules was uniform, their walls were transparency, and the microcapsules were provided with excellent sensitivity to heat, reversibility and solvent resistance.
Key Parameters Influencing Microcellular Polystyrene Cell Morphology Blowing with Supercritical CO2
Authors: Gao Chang Yun , Zhou Nan Qiao , Shan Ti Kun , Xin Zhen Xiang
Published: February 2012

Polystyrene microcellular foams blowing with supercritical CO2 were prepared with a novel polymer foam processing simulator. Key parameters influencing Polystyrene cell morphology were investigated. The effect of processing temperature and saturation pressure on cell morphology was observed by scanning electron microscope and the average cell diameter and cell size distribution was calculated. The results show that the cell density decrease and cell size increase with the increase of foaming temperature. The cell density increase and cell size decrease with the increase of saturation pressure. And the cell size distribution shows a narrow distribution at lower foaming temperature and higher saturation pressure.
Research on Optimization of the Process Parameters of Bio-Packaging Materials by Response Surface Method
Authors: Zeng Xian Kui , An Shuai , Wang Chuan Sheng , Bian Hui Guang
Published: February 2012

Response surface method was used to optimize the process parameters of bio-packaging materials, which is produced by twin-screw extruder, in order to get the best performance, increase production levels. In this article, we use the Design Expert software, Box-Behnken Design module, under the conduction that the mass fraction of starch, plant fiber, polyethylene were respectively 70%,10%,30%, and keep a plasticizer to 5%, We analysis and optimize the screw extrusion temperature, speed and filler content, The results showed that the optimum technology parameters for screw speed 101.81 r•min-1, extrusion temperature 118.24°Cand filler content is 5.0.
Simulation Analysis of Residual Stress of the Plastic Gear Based on Moldflow
Authors: Li Meng , Zhang Hui Min , Nie Yong
Published: February 2012

Through the orthogonal experiment with Moldflow software, numerical simulation was conducted in different injection molding process parameters. The influence on the plastic gear tooth root residual stress from the mold temperature, melt temperature, injection time, packing time, and packing pressure was explored was explored. The results showed that: The selected process parameters for plastic gear tooth root of the residual stress effects in varying degrees. By optimizing the injection molding process parameters, the residual stress of injection was reduced to improve the quality of injection molding gear.
Corrosion Resistance of TiN Imitation Gold Decoration Coatings on Golden-Pen Components
Authors: Hou Jun Ying , Zhou Zhi Wei
Published: February 2012

Experiments were carried out with different process parameters to investigate the effects of used parameters on corrosion resistance of TiN coatings obtained. In experiments, TiN imitation gold decoration coatings were prepared on 1Cr13 pen-point and brass chromium plating pen-coil by multi-arc ion plating method. The phase composition of TiN coatings was measured by x-ray diffraction. The corrosion resistance of TiN coatings was tested by salt-mist and artificial-sweat experiments. The relationship between corrosion resistance of coatings and process parameters were analyzed. Therefore, the optimum process parameters were achieved suitable for plating coatings on substrates of 1Cr13 pen-point and brass chromium plating pen-coil with good imitation gold. Imitation gold plating layers obtained have good gloss, corrosion resistance, high hardness, wear resistance, and easy to maintain. The results showed that the corrosion resistance of coatings is more easily influenced by changes of PN2 and Vbom than that of matrix-bias voltage. The TiN coatings are of resistant to corrosion no matter they are in single or multi phase structure. The optimum parameters of achieving good corrosion resistance of TiN coatings are PN2=0.48Pa, Vbom=400V，bias=-20V. Under the optimum conditions, the obtained surface corrosion resistance state of the coatings can reach at least eight grades, even above ten grades.
Research on Structure and Mechanical Properties of Epoxy Resin/Clay Nanocomposites by Shock Wave Method
Authors: Lin Guang Yi , Mu Xue Chen , Qu Dian Wei
Published: February 2012

Epoxy resin / clay nanocomposites prepared by shock wave method. The structure and mechanical properties including hardness, stress, strain and elongation at break were investigated. XRD was used to observe the interlayer spacing of the OMMT and SEM was used to survey the morphology of nanocomposites system. The results indicated that nano-montmorillonite can effectively increase the mechanical property of the material. The nano-montmorillonite was well dispersed in the epoxy matrix. The optimal process condition is that shock time 5min, nano-MMT content of 5%, duty cycle 1:3, shock depth 3cm.
Study on Conductive Properties of Composites Based on the In-Mold Laminating Technology
Authors: Zhong Yan , Xie Peng Cheng , Yang Wei Min , Ding Yu Mei
Published: February 2012

This paper introduced a new co-extrusion process which could increase layers by lamination-torsion-combination of polymer melt. The in-mold laminating technology was a kind of microlayed co-extrusion technology. The feasibility of the new technology on processing of polymer was validated. Conductive polypropylene filled with carbon black/polypropylene (PPCB/PP) composites was prepared using the novel device, the effects of processing parameters on conductivity of composites were researched. The results showed that the percolation threshold can decrease greatly.
Surface Tension Measurement by the Drop Volume Method
Authors: Du Dong Xing , Geng Dian Cai , Sun Shi Jiao , Li Ying Ge
Published: February 2012

Surface tension is one of the main physical parameters of foams. The surface tension of Sodium Dodecyl Benzene Sulfonate （SDBS）solution and Triton solution are measured by the drop volume method，and at the same time CO2 saturated SDBS solution is also measured in this paper. It is found the solution concentration has an obvious effect on the surface tension. For SDBS solution, the surface tension gradually decreases with the increase of surfactant concentration while keeps constant after a certain concentration. For Triton solution, on the other hand, the surface tension always remains approximately constant in the studied concentration region. The surface tension of CO2 saturated SDBS solution is slightly higher than SDBS solution through experimental investigations.
Finite Element Analysis of Turning Tire Active Mold Segment Using DEFORM-3D
Authors: Li Xiao Bin , Hu Hai Ming
Published: February 2012

By using DEFORM-3D to simulate the turing process of the tire active mold segment, the stress distribution, temperature distribution, strain distribution and cutting force transformation of turning tool and work-piece can be explored. The simulation results are helpful to configure the material and shape of the turning tools. Also the results play an important role in reducing development cost of the segment manufacturing technology and improving the accuracy and the lifetime of the mould segment.
Experimental Study on the Formula of Recycled Rubber Power Modified Asphalt
Authors: Wang Chuan Sheng , Wang Zhen Zhen , Zhang Hua
Published: February 2012

Recycled rubber powder modified asphalt is the trend of road asphalt, and rubber power is low cost, high performance modifier. In this experiment, by analyzing the equivalent softening point and equivalent crisp point, uses orthogonal experiment to obtain the formula that made the pavement property of recycled tire rubber powder modified asphalt for optimal.
The Wear Model Parameters Research of Cone Ring Sliding Plate on Tire Segmented Mould
Authors: Hu Hai Ming , Li Xiao Bin , Tian Zhong Ke
Published: February 2012

This paper researched the mating surfaces between sliding plates on cone ring and segment holders and discussed vertical clearance between segments caused by wear. Relationships between wear depth and parameter a, b, c and wear coefficient K of Archard wear model were analyzed. This work laid a solid foundation for confirming these coefficients accurately in the future.
Energy Saving Study on Carbon Black Pneumatic Conveying
Authors: Jiao Dong Mei , Li Yong
Published: February 2012

From the points of view of air compressor output pressure, by-pass pipe booster control modes and adjustable Laval nozzle of carbon black dense pneumatic conveying, the feasibility and quantity of energy saving of carbon black pneumatic conveying are analyzed. Several effective energy saving schemes of carbon black conveying are proposed. Then, industrial scale tests based on these schemes were carried out. By analyzing the data, energy saving of carbon black pneumatic conveying is calculated.
The Cathode Design in Electrolysis Deburring of Gear Face
Authors: Zhang Ming , Jiao Ju Ping , Liu Xiao Qiang
Published: February 2012

The paper take cathode design which is used for removing the burr of gear face as the object to study and use finite element method to solve the potential distribution of processing area.The paper adopt ANSYS software to simulate the dynamic process to determine the rationality of the cathode and propose revision method in order to satisfy the accuracy requirement.
Mechanical and Thermal Properties of Carbon Black Filled Natural Rubber and Fractal Analysis of Rubber Fracture Surfaces
Authors: Zhang Bin , He Yan , Ma Lian Xiang
Published: February 2012

Carbon black has been used as the main reinforcing fillers that increase the usefulness of rubbers. In this experiment, different compounds based on natural rubber were prepared with carbon black (N330) at various loading ratios from 10 to 125 phr. The mechanical and thermal properties of rubber compounds were measured and the test data with SEM micrographs were analyzed to determine the suitable ratio of carbon black for the desired properties of rubber compound. The results showed that carbon black particles were well dispersed in compounds with loading ratios of 25-30 phr, corresponding to maximum tensile strength values. While with the increase of carbon black content, heat conductivity kept sustained increase. Fractal dimension characterized the degree of uneven dispersion of carbon black in rubber fracture surfaces. A particular value of fractal dimension was obtained to characterize the optimum mechanical property of carbon black filled natural rubber. The thermal property and fractal dimension demonstrated same variation tendency.
The Numerical Simulating Research about the Pulse Cleaning Process of Bag Filter
Authors: Li Zhi Hua , Liu Jian Feng , Jiao Lei , Li Zhou , Peng Zong Xiang
Published: February 2012

With the computational fluid dynamics (usually being called “computational fluid dynamics” for CFD) method, the velocity field between the air nozzle and the filtering bag and the velocity distribution inside the filtering bag are computed when changing the distance between the air nozzle and the filtering bag. And the pressure distribution inside the filtering bag is also computed at different injecting times. According to the simulation result, this article has analyzed the influence of different distances between the air nozzle and the filtering bag and different injecting times on the dust-cleaning effect, and supplied theoretical basis to design the optimal pulse bag filter.
The Mathematical Modeling Linear Analysis of Triple Thread Single-Screw Pump
Authors: Wu Jun Fei , Yu Ying
Published: February 2012

The contrastive analysis and the linear optimization on the transverse plane linear of triple thread single-screw pump are used for outer equidistant curves of curtate hypocycloid and inner equidistant curves of curtate epicycloids. MATLAB programming language is used to solve the equations and plot linear, and express the analysis results intuitively. When the numeric area of variable amplitude coefficient is determined, it can get the relationship of overflow area with the variable amplitude coefficient k = e / r. So the analysis offers a reference for further study in triple thread single-screw pump.
Research on Crafts of Ni-P-Al2O3-SiO2 Electroless Composite Plating
Authors: Hou Jun Ying
Published: February 2012

In order to obtain the composite coatings of abrasion resistance and anti-corrosion, experiments of Ni-P-Al2O3-SiO2 chemical composite plating were carried out by electroless composite plating technology, and then the added amount of composite particles influenced coatings performance were investigated. After experiments, the metallographic structure, the micro-hardness, bonding strength, thickness and anti-corrosion of composite coatings were characterized by using a XJZ-6A type metalloscope and a HVS1000 type micro-hardometer, respectively. The results show that the composite coatings have bright surface appearance and the properties of bath are stable. Besides having a higher hardness, a higher thickness and a lower porosity, composite coatings combine well with the matrix and the abrasion resistance is better when the amount of Al2O3-SiO2 composite particles were added correctly. These composite particles should be treated by ultrasonic vibration firstly.
Morphological and Flame Retardant Behaviors of Rubber-Modified Asphalt
Authors: Borah Jyotishmoy , Wang Chuan Sheng
Published: February 2012

Rubber modified asphalt mixtures were prepared by reaction of asphalt by chemical mixing with waste rubber. The fundamental properties like homogeneity, thermal etc. of the modified asphalt mixture was investigated by using different techniques like SEM, TGA, DSC analyses etc. The flame retardancy of mixtures was investigated LOI tester. Results shows that antimony oxide is marginally better fire retardancy to asphalt blends than magnesium oxide Mg(OH)2
Prediction of Tire Inflated Shape Based on Pressure Function Method
Authors: Li Li , Wang Jiang Zhong
Published: February 2012

The prediction of tire inflated shape is significant to tire structure design. In this paper, the mathematic-physical equations were established by using pressure function method and then the prediction of tire inflated shape was numerically accomplished. The obtained results agree well with the actual tire shapes, verifying the pressure function method. The present work gives a prediction method in designing futuristic tire shapes and could be applied to the mechanics analysis of inflatable tire and optimization design of tyres.
Dynamic Simulation of 3D Fluid Field for Four-Wing Synchronous Mixer Rotor and Four-Wing Asynchronous Mixer Rotor
Authors: Chen Chun Ping , Wang Chuan Sheng , Zhang Meng
Published: February 2012

The physical, mathematical and finite element models for the four-wing synchronous rotors and four-wing asynchronous rotors in internal mixer were established in this paper. By comparative analysis of the two types of processes involved in mixing process the pressure field, the velocity field and the concentration field, the viscosity field and the mixed exponential distribution on its 3D fluid field dynamic simulation were computed by the polyflow software. The results showed that the four-wing synchronous rotors were better than the four-wing asynchronous rotors in a number of performance parameters.
Study on Thermal Conductivity of Filled Silicone Rubber
Authors: Ma Lian Xiang , Xu Jin , He Yan , Ke Jia Na
Published: February 2012

The heat conductive silicone rubber is prepared with methy1 viny1 silicone rubber as basic gum and SiCp (SiC particle), SiCp/SiCw (SiC whisker), graphite as heat conductive fillers. The effects of filler amount, filler shape, filler size and coupling agent on the thermal conductivity of silicone rubber have been studied in this article. The result shows that when the filling amount is increasing, the thermal conductivity of composite silicone rubber will increase too. There is no evident change for thermal conductivity with the small filling fraction, while the filling amount reaches a certain value, the thermal conductivity of composite increases obviously. Moreover, the thermal conductivity added with coupling agent (KH-602) is higher than that of composite without coupling agent addition.
Review of Research Progress on Galling in Sheet Metal Forming
Authors: Hou Ying Ke , Li Y.P. , Yu Zhong Qi , Zhao Yi Xi , Li Shu Hui
Published: February 2012

Galling is a known failure mechanism in sheet metal forming. It results in increased cost of die maintenance and scrap rate of products. For high strength steels, problems with galling are of major interest, since forming pressure is high as well as shear stress. In the last ten years, significant progress has been made on development and understanding of galling in sheet metal forming. In this paper, the main test apparatus and the methods used to reduce galling tendency are reported. And the galling mechanisms of galling are also analyzed.
Virtual Verification of an Aircraft Final Assembly Line Industrialization: An Industrial Case
Authors: Menéndez J.L. , Mas F. , Serván J. , Ríos J.
Published: February 2012

This communication describes the experience gained when implementing a Digital Manufacturing methodology to validate the industrial design of the AIRBUS A400M Final Assembly Line using commercial Product Lifecycle Management tools. The implementation project generated a remarkable innovation in the industrialization methods and tools used in AIRBUS Military, contributing to the A400M program success. The document presents: the background and reasons motivating the project, the context, the main barriers identified and the definition of a Final Assembly Line (FAL). An innovative concept of industrial Digital Mock-Up (iDMU) was coined, representing the interoperable grouping of product, processes and manufacturing resources data.
Aircraft Final Assembly Line Balancing and Workload Smoothing: A Methodological Analysis
Authors: Ríos J. , Mas F. , Menéndez J.L.
Published: February 2012

Assembly Line Balancing (ALB) comprises ordering of tasks among workstations to satisfy precedence constraints and objective functions. Due to the specific features of an aircraft, such approach is not fully suitable for the case of an aircraft Final Assembly Line (FAL). Where, the number of workstations relates to technological criteria rather than to a calculation aiming to minimize a specific parameter. Workload smoothing is addressed once the FAL configuration is defined. To improve current practices, a methodological approach was taken to address the conceptual modeling of an aircraft assembly line.
Clean Manufacturing from Cradle to Cradle
Authors: Peralta M.E. , Aguayo González Francisco , Lama Ruiz Juan Ramón
Published: February 2012

The sustainability of manufacturing processes lies in industrial planning and productive activity. Industrial plants are characterized by the management of resource (inputs and outputs), processing and conversion processes, which usually are organized in a linear system. Good planning will optimize the manufacturing and promoting the quality of the industrial system. Cradle to Cradle is a new paradigm for engineering and sustainable manufacturing that integrates projects (industrial parks, manufacturing plants, systems and products) in a framework consistent with the environment, adapted to the society and technology and economically viable. To carry it out, we implement this paradigm in the MGE2 (Genomic Model of Eco-innovation and Eco-design), as a methodology for designing and developing products and manufacturing systems with an approach from the cradle to cradle.
Holistic Approach to Information Search Based on Six Sigma
Authors: Otero Manuel , Pastor Andrés , Portela José M. , Viguera J.L. , Huerta Milagros M.
Published: February 2012

A research paper should generate new questions and is cyclical in nature, where answers to research questions of today will be the base for the research questions of tomorrow [. To facilitate this work, we propose a holistic approach to information search, in addition to an overview and orderly search process to determine the state of the art, it helps the investigator under any circumstances, to find new lines of work or tendencies in any subject under analysis.
Implementing Manufacturing Features in Mechanical Design
Authors: Szecsi T. , Hoque A.S.M.
Published: February 2012

This paper presents a design system that enables the composition of parts using manufacturing features. Features are selected from feature libraries. Upon insertion, the system ensures that the feature does not contradict the design-for-manufacture rules. This helps eliminating costly manufacturing problems. The system is developed as an extension to a commercial CAD/CAM system Pro/Engineer.
Initial Methodology for Sustainability Comparison among Materials Processing
Authors: Sevilla L. , Peinado B. , Sebastián M.A.
Published: February 2012

Currently, when the most suitable material manufacturing process is chosen, not only technical or economical aspects have to be considered, otherwise, it has to emphasize its sustainability. In this document, an easy method to compare mass reduction processes and mass conservation processes, with an application to compare drawing process and machining process, is shown. The comparative comparison makes possible to justify that plastic deformation processes usually have more advantages.
Integration of Quality, Labor Risks Prevention, Environment and Ethical Management. Model Applied to R&D&I and Manufacturing Processes in an Organization
Authors: González R. , Torres F. , Yoldi V. , Plaza I. , Arcega F.
Published: February 2012

In this paper, it is proposed an integrated management model applied to R&D&I and manufacturing processes for an organization. The model intends to integrate the environmental, risk prevention and ethical aspects as well as research, development and innovation projects management in the general quality management structure proposed by ISO 9001:2008. Specifically, it tries to fulfill the standards ISO 9001, ISO 14001, OSHAS 18001, SGE 21 and UNE 166002. The global structure is based on the continuous improvement Plan-Do-Check-Act cycle. The main advantages of this integrated management system are detailed, specifically the optimization of the documentation which results in the reduction of costs of implementation and maintenance.
Heating Carve Technique for Polymer Microfluidic Microchannel
Authors: Han Xiao Wei , Wang Wei , Ye G.H. , Liu Xiao Wei , Tian Li , Mao Zhi Gang
Published: February 2012

A new manufacture mainly for polymethyl methacrylate (PMMA) microfluidic chips is presented in this paper. In this technique, polymer microfluidic microchannels were fabricated by microcutter which temperature is controlled and stabilized by PID methord. There are so many techniques, such as hot embossing, laser direct-write, for mass-production of polymer microfluidic chip. However, we may feel different kinds of shortages when we use these techniques. In this paper, the experiment result shows that microcutter’s movement velocity and temperature have effert on microfluidic microchannel’s roughness.
Design and Analysis of a Monolithic 3-Axis Micro-Accelerometer
Authors: Wang Xing Hua , Chen Zhi Hua , Xiao Ding Bang , Wu Xue Zhong
Published: February 2012

Due to many inherently problems of accelerometers on market, such as complex fabrication process and low precision, a monolithic three-axis accelerometer is proposed and fabricated. The 3-axis accelerometer consists of four individual seismic mass, each has a wafer-thick of 240μm and is fabricated by anisotropic wet etching technology. In this paper, the design, fabrication, and characterization of the 3-axis accelerometer are presented. The performance is characterized and demonstrated.
A High-Performance Closed-Loop Fourth-Order Sigma-Delta Micro-Machined Accelerometer
Authors: Lv Bing Jun , Wang Peng Fei , Wang Dong Bo , Liu Jun'an , Liu Xiao Wei
Published: February 2012

In this paper a high-performance closed-loop fourth-order sigma-delta (ΣΔ) micro-accelerometer is presented. After a introduction of sigma-delta accelerometer, system-level analysis and design of a fourth-order sigma-delta micro-accelerometer is given. The simulation result shows that an accelerometer with 107dB signal to noise ratio (SNR) and 17.5 bits effective number of bits (ENOB) is achieved. Through the root locus analysis, it is got that accelerometer is stable when quantization gain is bigger than 0.262. The accelerometer gets a good linearity and it becomes overload when input signal level is greater than -5dBFS.
A Simple Method for Depositing DNA on the Mica
Authors: Wang Yu Zhang , Sha Jing Jie , Liu Lei , Fu Hong Yan , Chen Yun Fei
Published: February 2012

For studying DNA electrical double layer in electrolyte solution, the key process is to create the template for DNA processing. In this paper, we described a straightforward method for depositing DNA on a substrate. The mica was chosen as the substrate materials because of its atomically flat and negatively charged surface in solution, and mica was coated by the polylysine to absorb the DNA molecules. Using by AFM, the DNA molecules have been probed obtaining a high resolution in air and liquid, and the method is simple and easy operated. This method can be used for nano-manipulation and the quality of the DNA under physiological conditions.
A Silicon Micro-Accelerometer with Triangle Cross-Section Beam by Anisotropic Wet Etching in TMAH Solution
Authors: Lv Yu , Cui Hong Juan , Dong Pei Tao , Chen Zhi Hua , Wu Xue Zhong
Published: February 2012

A capacitive accelerometer with triangle cross-section beam fabricated by anisotropic wet etching of (100) silicon is presented in this paper. The feature of this accelerometer is that eight suspension beams with triangle cross-section are formed by anisotropic wet etching of (100) silicon in TMAH solution, without heavy boron doping or Si-Si bonding. When the width of beam is decided, the beam’s geometry is determinate. The formation procedure of the triangle cross-section beam is analyzed in detail. Through this beam-fabrication approach, the beam’s thickness can be well controlled by beam’s width and intrinsic stress in the beams is minimized. Accelerometers with different sensitivities can be easily fabricated by varying the width of the beams. For a device with 23 μm width beams, the resonance frequency and the quality factor are 644 Hz and 32, respectively. The sensitivity of accelerometer is measured as 2 V•g-1.
Design and Simulation of a Capacitive Biaxial Microaccelerometer
Authors: Liu Yu , Wen Zhi Yu , Chen Li , Yang Hong Yun
Published: February 2012

This paper presents a capacitive biaxial microaccelerometer with a single proof mass. The theoretical analysis results are conﬁrmed by ﬁnite element analysis. The experimental results indicate the biaxial accelerometer with uniform axial sensitivities, good linearity and high cross-axis sensitivity immunity to the z-axis input.
A Novel Preconcentration Method for Microchip Based Electrophoresis and its Numerical Simulation
Authors: Cai Hao Yuan , Chen Xing , Li Hui , Cui Da Fu
Published: February 2012

A novel preconcentration method for efficient DNA sample stacking during sample introduction and injection in microchip electrophoresis is presented in this paper. The method suggests that a pair of sample stacking electrodes is designed after the double-T section. A sample stacking electrical field can be established after sample introduction inside the double-T section, so that the sample stacking procedure can be controlled accurately and efficiently. In order to test this method’s validity, a numerical model is setup using COMSOL Multiphysics software. The simulation result shows that the peak DNA concentration can be increased up to 10 fold by this method. These results demonstrate the great potential for significantly enhance DNA sequencing speed and resolution in microchip electrophoresis.
Analytical Model of Fluxgate System
Authors: Ren Ming Yuan , Liu Xiao Wei , Li Hao Ran , Mao Zhi Gang
Published: February 2012

This paper presents a complete set of SIMULINK models, which allow exhaustive behavioral simulations of fluxgate system to be performed. The model construction is detailed and it is applied to the Vacquier-type fluxgate sensor. Well known characteristics of these sensors are confirmed through the simulations. In spite of this simplicity, the model has been successfully used to describe the variation of the output of a Vacquier-type fluxgate sensor with the amplitude and the frequency of the driving current. Using a previously developed 2nd harmonic fluxgate magnetometer, some preliminary experimental results are obtained confirming the appearance at its output.
Analysis of Broken Wires during Gold Wire Bonding Process
Authors: Pan Ming Qiang , Chen Tao , Chen Li Guo , Sun Li Ning
Published: February 2012

Wire bonding is one of the critical technologies of devices production, assembly and packaging in the microelectronic and MEMS field. During bonding process, the gold wires break easily, because the wires are repeatedly operated with high-speed. Therefore, the experiments were performed to analyze bonding process and the reason causing wire break. The results show that it is critical to prevent the broken wire to control the pressure wire pressure, the speed and angle of the pulling wire structure, the clamp gap, the capillary tip gap, and discharging energy in bonding process. the broken wire doesn’t occurs when the pressure wire pressure, the speed of the pulling wire structure, the angle of the pulling wire structure, the clamp gap, the capillary tip gap, the time and the current are 3-5g, 5rad/s and 10rad, 0.1-0.3mm, 1mm, 35ms and 10mA , respectively.
Analysis and Simulation of Micro-Fluidic Inertial Switch
Authors: Lin Yi , Yang Tao , Liu Ting Ting , Chen Guang Yan , Wang Chao
Published: February 2012

This paper presents a micro-fluidic inertial switch with varying rectangular cross section, which employs the moving mercury droplet in the micro-channel to close a switch. Combining the Young-Laplace formula with the structure, the formula of the threshold g-value is derived. The influence of design parameters of microchannel on the threshold g-value is analyzed. Based on the VOF approach containing contact angle effects, the dynamic behavior of mercury droplet in the microchannel is simulated using Fluent. The response time is predicted through simulation with the contact angles ranging from 130° to 170°. In addition, the dynamic process of inertial switch is simulated, and the result indicates that the selected design parameters can achieve reliable switching under given threshold g-value.
Numerical Simulation of Multi-Physical Fields Coupling and Design of a Digital Microfluidics Chip
Authors: Chen Tao , Chen Li Guo , Pan Ming Qiang , Ling Ming Xiang , Sun Li Ning
Published: February 2012

Due to its simple structure, low consumption of energy but strong driving forces, Electrowetting on Dielectric (EWOD) is used most frequently in digital microfluidics for manipulation and control of droplets. In this paper, the internal mechanism of EWOD is explained though establishing the geometric model of the unipolar board structure digital microfluidic chip. And the boundary conditions of equations are determined. Three coupling physical fields: electric field, flow field and temperature field in the digital microfluidic chip are simulated and analyzed. With the electric field equation coupled, Navier-Stokes equations and energy equation of the temperature control, the numerical simulation of the chip is conducted. The results show that the internal flow of micro-droplets is counterclockwise and swirling flow. The external flow velocity of micro-droplet is greater than the internal velocity. In addition, micro-droplets near the electrode applied temperature are higher than the internal temperature. Surface micromachining technologies are employed to fabricate the chip. Experimental results show that the droplet can be driven in a velocity of 25cm/s. It will possibly provide an effective solution to the manipulation of droplets.
An Improved Sensitivity Non-Enzymatic Glucose Sensor Based on a Nano-Gold Modified Ag Electrode
Authors: He Jia Hong , Xu Qiang , Gao Zhi Qiang , Song Zhong Rong
Published: February 2012

A non-enzymatic glucose sensor based on nano-gold modified Ag electrode was fabricated by two steps. Gold colloid were firstly prepared according to the literature[11] and then a carefully cleaned Ag electrode was dipped into the gold colloid to obtain the non-enzymatic glucose sensor. The structures and morphologies of nano-gold colloid and nano-Au modified electrode were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and UV-Vis absorption spectra. The direct electrocatalytic oxidation of glucose in alkaline medium at this modified electrode has been investigated in detail. The result showed that the nano-gold modified electrode had good current response to glucose. The oxidation current was linearly related to the concentration of glucose range frome 0.2 to 175.2μmol/L with a detection limit of 29.5 nmol/L. The nano-gold modified electrode allows highly sensitive, low working potential, fast amperometric sensing of glucose, thus is promising for the future development of non-enzymatic glucose sensors.
A Miniaturized Piezoelectric Wind Flutter Generator
Authors: Zhao Xing Qiang , Wen Zhi Yu , Du Zhi Gang
Published: February 2012

A novel miniaturized piezoelectric wind flutter generator is proposed which consisted of a flexible beam and a PZT cantilever. The working principle is based on flexible beam flutter, which can amplify the PZT cantilever vibration. A prototype was tested in a wind tunnel. It is found that there are three behavior states with wind speed increasing, and flutter behavior takes place when wind speed varies between the critical wind speed Uc1and Uc2, an empirical formula was obtained about the critical speed Uc1. The open circuit voltage and power were measured. The device can generate 794μW output power with 30kΩ resistor in a wind of speed 20m/s, power density is 139μW/cm3.
Material Flow in Sheet-Bulk Metal Forming
Authors: Vierzigmann Ulrich , Koch Johannes , Merklein Marion , Engel Ulf
Published: February 2012

Innovative trends like increasing component functionality, the demand for automotive lightweight constructions and the economic issue to optimize existing process chains, require new ways in manufacturing. Today, the traditional sheet metal and bulk metal forming processes are often reaching their limits if closely-tolerated complex functional components with variants have to be produced. A promising approach is the direct forming of high-precision shapes starting from blanks. Thus, classic sheet metal forming operations, such as deep drawing, are combined with bulk metal forming operations like extrusion of complex variants as for example teeth. This combination of sheet and bulk metal forming operations leads to a side by side situation of different tribological conditions according to the locally varying load situations within the same forming process. This new class of forming processes is defined as sheet-bulk metal forming (SBMF). The tribological conditions in sheet-bulk metal forming processes are of major importance for the process realization, its stability and for the quality of the produced part. The objective of this paper is the investigation of material flow in SBMF in general and the attempt to improve the material flow by local adapted tribological conditions. First the material flow was analyzed by FE-simulation of a model geometry that is typical for SBMF. The investigations with FE-simulation have shown, locally adapted tribological conditions are leading to an improvement in material flow and thus to an increased mould filling. As frictional conditions are directly connected to the topography of workpiece and tool, the modification of the workpiece topography is leading to an alteration in friction values. For the modification of workpiece topography grit blasting was used. The increase in friction of grit blasted surface towards untreated surface was investigates by using the laboratory friction tests. To manufacture specimens with locally adapted topographies for forming tests a masking technique has been developed. The masks are designed after the preliminary findings determined by FE-simulation.
Experimental Determination and Modeling of Thermal Conductivity Tensor of Carbon/Epoxy Composite
Authors: Lecointe Damien , Villière Maxime , Nakouzi Sawsane , Sobotka Vincent , Boyard Nicolas , Schmidt Fabrice , Delaunay D.
Published: February 2012

In this study, the effective thermal conductivity tensor of carbon/epoxy laminates was investigated experimentally in the three states of a typical LCM-process: dry-reinforcement, raw and cured composite. Samples were made of twill-weave carbon fabric impregnated with epoxy resin. The transverse thermal conductivity was determined using a classical estimation algorithm, whereas a special testing apparatus was designed to estimate in-plane conductivity for different temperatures and different states of the composite. Experimental results were then compared to modified Charles & Wilson and Maxwell models. The comparison showed clearly that these models can be used to accurately and efficiently predict the effective thermal conductivities of woven-reinforced composites.
Mechanical Analysis and Simulation of the Thermoforming Process of Thin Polymer Sheets
Authors: Ahmad Daniel , Hamila Nahiene , Lamnawar Khalid , Boisse Philippe
Published: February 2012

Most of industrial processes (thermoforming, injection moulding...) require the understanding of thermo-mechanical behaviour of polymeric sheets. Furthermore, the mastery of the deformation of the polymers becomes an important stake. In order to improve and complete the understanding of the deformation of thermoplastic polymer materials during their forming processes, the problem of modelling the thermoforming process for viscoelastic sheet under large strains is considered. The first step of the process that consists in heating the sheet using infrared lamps is taken into account by included a temperature field in viscoelastic behaviour laws under integral forms. The finite element simulation of the different steps will be presented
Shape Evolution of Carbon Epoxy Laminated Composite during Curing
Authors: Nawab Yasir , Jacquemin Frederic , Casari Pascal , Boyard Nicolas , Sobotka Vincent
Published: February 2012

The laminated composites undergo chemical deformation on cross-linking and thermal deformation while cooling during fabrication process. In thin laminates, due to large displacements and complex shape evolution, these deformations can only be explained by using nonlinear strain-displacement relationship. In the present article, the thermal and chemical deformations occurring in carbon/epoxy laminates are calculated together for the first time by considering a non-linear geometrical approach, to understand the evolution of shape and hence residual stresses induced during fabrication process.
Analysis of Surface Reaction Mechanisms on Electrically Non-Conductive Zirconia, Occurring within the Spark Erosion Process Chain
Authors: Hösel T. , Müller Claas , Reinecke Holger
Published: February 2012

Electrically insulating high performance ceramics like zirconia are increasingly used for high technological applications due to their extraordinary properties. Meanwhile even the spark erosion process can be used to structure non-conductive ceramics by using an assisting electrode (AE). This conductive AE is placed on top of the work piece to enable the process. The electrical contact is sustained during the process by carbonic residua of cracked oil used as a dielectric. For an enhanced understanding of the removal mechanisms during the spark erosion process of such non-conductive ceramics, we analysed the surface of ceramic samples during the entire spark erosion process chain. In our investigation a zirconium oxide with yttrium oxide stabilisation was chosen. For this purpose X-ray diffraction (XRD) and scanning electron microscopy (SEM) analysis was performed. The XRD results showed that the zirconium oxide reacts under the presence of carbonic residua during processing into zirconium carbide. This material supports sustaining the conductivity additionally, as it is conductive itself. In a subsequent thermal cleaning step with oxide atmosphere (T = 750°C), remaining carbonic residua are oxidised and thus removed. The XRD measurements after cleaning showed that the zirconium carbide was no longer detectable. Instead a monoclinic zirconium phase was found. This shows that a reverse reaction of zirconium carbide into zirconium oxide took place. To prevent the formation of a non-stabilised monoclinic phase, the oven process was adapted to higher temperatures of 900°C with higher heating and active cooling rates of up to 10 K/s. This adjustment shows that the monoclinic phase can be supressed and the reverse reaction leads to a tetragonal zirconium oxide like the bulk material.
Numerical Simulation of Open-Cell Aluminum Foams under Compression
Authors: Quadrini Fabrizio , Bellisario Denise , Ferrari Daniele , Santo Loredana
Published: February 2012

The numerical simulation of the compression behavior of open-cell aluminum foams is discussed as a way to extract material property information for laser forming simulation. A bilinear isotropic model was implemented for the alloy base material whereas a parametric approach was used to build the finite element model of the foam structure. Compression tests were performed on commercial foams with different pore size and density, and the results of lower density foam were used for the model validation. Numerical results show a good agreement with experimental data in terms of foam deformation under compression and required loads.
Research on Unconventional Methods of Cylindrical Micro-Parts Shaping
Authors: Skoczypiec Sebastian , Grabowski Marcin , Ruszaj Adam
Published: February 2012

One can state that special place in group of micromanufacturing methods are connected with application of unconventional methods, such as electrochemical (EC) and electrodischarge (ED) micromilling, because of their high efficiency in shaping 3D structures. In the paper result of cylindrical tools manufacturing for EC and ED-micro milling process will be discussed. The special attention will be paid for electrochemical etching, electrodischarge turning and some hybrid methods application for micro-tools manufacturing
Forming Limits for Shrink Flanges of Rubber Formed Parts
Authors: Sinke J.
Published: February 2012

Rubber forming is an ideal process for the manufacture of a wide variety of flanged parts in small products series, and is attractive for industries like the aircraft industry. The flanges of a formed part are straight, stretch or shrink flanges, each type having its own limits. The forming limits for the straight and stretch flanges are dominated by the formability of the material and the applied strains, which are related to the (local) geometry of the flange. The prediction of the limits for the shrink flanges is much more complicated, since both plastic flow and instability play a role. In recent years, a number of authors developed methods for the prediction of wrinkle formation in metal sheets in different applications. This paper focuses on an alternative approach for the prediction of failure limits of shrink flanges. Shrink flanges wrinkle right from the start of forming process. At first the deformations are elastic, but for the creation of flanges the material has to become plastic. The geometry of the cross-section of the wrinkles can be approximated by sinusoidal shapes having a length and amplitude. During processing the values of both parameters decrease, although the ratio of the two is even more important and should decrease in order to obtain a wrinkle-free part. In the paper the topic is addressed using experimental data, showing the influence of the most important variables like materials properties, strain values, and variables like thickness. Subsequently the parameters are used to provide relations between the different variables, which are used for numerical simulations.
Performance Evaluation of Cryogenically Treated Worn CBN Insert by Turning Process
Authors: Thamizhmanii S. , Rajendran K. , Rasool Mohideen , Hassan Sulaiman
Published: February 2012

Machining of materials is to produce desired shape and size with smooth surfaces for the performance. Machining is carried out using various cutting tools starting high speed steel to recently developed tools like CBN and PCBN etc. These tools are used to machine difficult to cut materials like high strength alloy steels, stainless steel, Inconel 718, Titanium etc. The inserts used are thrown out or no longer required for finish machining. It can be used for rough machining where smooth surface is not primary important and subjected to subsequent machining using fresh inserts. The used inserts can be used subsequently by subjecting them cryogenic treatment at – 196◦ C in a closed chamber. It is longer process for more than 30 hours in a liquid nitrogen chamber. This treatment gives additional strength to cutting inserts to improve the cutting ability and wear resistance. The components used in high strength applications like an aerospace, automobile industries are treated with cryogenic process to improve wear strength. The operating parameters are cutting velocity, feed rate and constant depth of cut. In this research, CBN inserts after turning for 750 mm length was cryogenically treated and again used with same operating parameters as previous machining conditions. Each inserts were measured for flank wear by Scanning Electron Microscope (SEM) after treatment and re-used with same turning conditions as before. Performances of all inserts used were producing the same results or results near to same. The treated inserts were acting as fresh cutting edges. The results showed that cryogenically processed CBN inserts performed very close to previous results.