bluuebunny/crossref_metadata_2025 huggingface dataset:
Experimental Investigation for Horizontal Ultimate Bearing Capacity and Target Ductility Factor Improvement Results of the RC Column Reinforced by AFL with Damages
Authors: Zou You Lin , Huang Pei Yan
Published: January 2014

Deem test results from the low reversed cyclic loading quasi-static test with 2 RC columns as the basic information of secant stiffness damage of the reference column and take use of the TMS instrument in the test to artificially make the damage percentage of secant stiffness of the RC column as 33%, 50% and 66%, 6 damaged columns in total; reinforce the 6 damaged columns and 2 undamaged ones under the same conditions with AFL, through quasi-static contrast test. Test results show that it is able to effectively boost horizontal ultimate bearing capacity and ductility deformability of the RC columns with AFL for reinforcement; besides, there is a linear function relationship between horizontal ultimate bearing capacity, target ductility factor, and damage percentage of secant stiffness.
Influence of CVD Parameter on Structure of Graded SiC-C Coating
Authors: Yu Yan Li , Fu Zhi Qiang , Wang Cheng Biao
Published: January 2014

The influence of chemical vapor deposition process parameters including carrier gas composition, deposition temperature, and content of reactants on the structure of graded SiC-C coating is discussed on the basis of thermodynamic calculation in this paper. The addition of enough hydrogen into carrier gas is necessary for the fabrication graded SiC-C coating. The increase of deposition temperature benefits the control of composition in graded coating but the concentration of free Si and free C becomes high at a too high deposition temperature. A high concentration of reactants is preferred while more defects are apt to exist in coatings if the concentration of reactants is too high. The optimum CVD process parameters for graded SiC-C coating are: gradually changing the molar ratio of SiCl4 and CH4 from 0 to 1 when the concentration of CH4 in hydrogen is 1-2 vol%, and the deposition temperature is 1200-1500 °C.
Finite Element Simulation Analysis of Clay Inclined Wall Dam
Authors: Liu Ke Ding
Published: January 2014

Clay inclined wall dam is a common structure in hydraulic engineering, this paper adopts universal finite element calculation software to carry out three-dimensional finite element simulation analysis for clay inclined wall dam of Xindian reservoir. Computer is fully used in calculation process, researching variation law of the dams stress and displacement in construction process and operating process. The research results offer some reference for design and construction of clay inclined wall dam.
Simulation Analysis for Reinforced Concrete Aqueduct of Lijia Pumping Station
Authors: Xie Xiang Zan
Published: January 2014

Reinforced concrete masonry arch aqueduct is a common water diversion engineering structure. Aqueduct is decorated on the concrete cushion layer, cushion layer effects on masonry arch, the structures stress is uniform, carrying capacity is strong. This paper adopts finite element method to carry out force analysis for reinforced concrete masonry arch aqueduct of Lijia pumping station, considering aqueduct weight, water pressure and earthquake effect, etc. Researching stress and deformation distribution law of reinforced concrete masonry arch aqueduct.
Experimental Study on Compressive Mechanical Performance of Fly-Ash Thermal Insulation Hollow Block Masonry
Authors: Zhou Xiao Jie , Song Jin Ke , Jiang Xu Liang , Xu Dan Dan
Published: January 2014

Non-autoclaved and non-sintered fly-ash perforated brick is a kind of new material for non-load-bearing walls. In order to promote the application of this new material in village and town buildings of seismic area, compression and shear strength of non-autoclaved and non-sintered fly-ash perforated brick masonry was tested and crack and failure progress was analyzed. The test results show that the failure processes and characteristics of the non-autoclaved and non-sintered fly-ash perforated brick masonry in compression and in shear are similar to that of the common brick masonry, however the non-autoclaved and non-sintered fly-ash perforated brick masonry tend to fail in brittle manner. The compression and shear strength are all less than that of the common brick masonry. A mathematic model of 6 degrees polynomial was used to express the compressive constitutive relationship and the whole process of non-autoclaved and non-sintered fly-ash perforated brick masonry in compression was described. The curve was close to the measured data.
Simulation Analysis of K Node on UHV Transmission Tubular Tower
Authors: Gao Yuan , Li Mao Hua
Published: January 2014

Layout for K node of steel tubular UHV transmission tower is analyzed in systematic and all-sided with finite element calculation in this paper. The recommendation is that as no applicable formula is available at present, existing specification can still be used for calculation but with a safety margin of more than 10%. K node connected in intersecting welding manner with appropriate stiffening rib will improve the stress, gender more uniformed stress distribution, and effectively reduce stress concentration. Welding connection features smaller displacement and maximum stress and more uniformed stress distribution relative to plug-in connection, therefore it is recommended to be used for K node with slope.
Research on Welding Operation and Safety Measures
Authors: Wen Li Juan
Published: January 2014

In this paper, adhering to the "safety first, prevention first" concept, analyze the reason for the accident risk may occur during welding operations, and puts forward the safety prevention measures. To ensure the welding process of construction personnel and property safety.
Experimental Study of Bond Stress between Concrete and FRP Rebars
Authors: Yu Nan Hui , Fan Ji Jun
Published: January 2014

Owing to the excellent tensile strength and corrosion-resistance of fiber reinforced unsaturated polyester composite, it is expected to solve the corrosion problem of building instead of steel bars in some special occasions. Bonding performance between concrete and FRP rebars was studied by pull-out test,the influences of the surface form, anchorage length and diameter of FRP rebar on bonding strength were discussed in detail.
The Shift Time of Reflection Sh-Wave on an Interface of Two Media
Authors: Wang An Ling , Liu Fu Ping
Published: January 2014

Using the phase shift of reflection coefficient of SH seismic wave at the interface of strata, we derived the shift time of total reflected SH-wave, given formulae of shift time,The results show that for glancing wave or angle of incidence being near the critical angle, the shift time are very large. A large shift can be caused,In other angle of incidence the shift time is the same order of magnitude as the wavelength (period).
Movement Dynamics Analysis and Optimization for External Powered Gatling Gun
Authors: Gao Ying , Bo Yu Cheng , Yang Zhen , Zhang Peng Jun
Published: January 2014

More driven torque is required to the external powered gatling gun, in order to lower the driven torque, this paper analysed the influence on automatic driven torque by cam parameters, established the kinetic mathematical model of bolt system, deduced the equation of driven torque, found out two reason which lead to over-torquing. This paper optimized the cam curve and increased the angle of accelerating under the circumstance of fixed pre-interval phase and ensured only one bolt in the phase of accelerating. After calculation, optimized cam curve reduced the driving torque in large quantity, and reduced the power consumption.
Design of PDF Template Based Solution for Preformatted Paper Printing
Authors: Ye Shi Ping , Ding Jian Long
Published: January 2014

As traditional Preformatted Paper Printing methods can't adapt to the changes of document style and they have made poor performance on document security, in this paper, we have presented a PDF-based solution for Preformatted Paper Printing. The solution consists of three levels, including data organization layer, template editing and configuration layer, and PDF file generation layer. The data organization layer is mainly to solve the problem of data extraction and summary from heterogeneous databases. The template editing and configuration layer focuses on solving the printing template design and data output mapping problem. The PDF file generation layer is mainly to generate and merge the PDF file using iTextSharp component. The scheme can flexibly adapt to changes in content and style, set up parameters simultaneously to prevent a tamper, and undertake operations such as reprint, archive, distribution and so forth. At last, we have verified the solutions performance by the case of university admission notice-Generating. The result shows that our solution is effective.
Pressure Modeling of Combination Electronic Unit Pump Fuel Pipeline with Rapeseed Methyl Ester
Authors: Hayat Qaisar , Fan Li Yun , Ma Xiu Zhen , Tian Bing Qi , Song En Zhe , Naeim Farouk
Published: January 2014

An alternate biodiesel fuel Rapeseed Methyl Ester (RME) has been evaluated for diesel engine Combination Electronic Unit Pump (CEUP) fuel injection system. Pressure wave modeling of CEUP high pressure fuel pipeline using viscous damped wave equation has been done in MATLAB at various operating conditions of diesel engine. Finite Difference method has been used to model and simulate wave equation at eleven equidistant locations along fuel pipeline. Results show increase in pressure, density, acoustic wave speed and bulk modulus amplitudes with RME fuel as compared to conventional diesel fuel.
Lignin Waste Polyurethane Cushion Packaging Materials Research
Authors: Wang Ju Wei
Published: January 2014

Polyurethane (referred to as PU) is a polymer made from polyisocyanate and a polyether polyol or polyester polyol and small molecule polyol, polyamine or water chain extenders or crosslinking agent, such as raw materials. By changing the type of material and composition, you can dramatically change the form of products and their performance, the final product from soft to hard. Lignin, a natural renewable resources, natural aromatic polymer has a hydroxyl-containing three-dimensional structural characteristics, the research and application has become increasingly active. The introduction of the lignin in the material, not only can improve the performance of the material but also reduce costs, resulting in considerable economic benefits. If we can combine the two advantages of the manufacture of composite materials to become a demand.
The subjects explored the impact of the alkali lignin waste polyurethane foam and curing agent on the performance of the polyurethane foam through experiments that the above factors, the ratio of the manufacture of polyurethane foam: phenolic resin 250g, adding emulsifier 30g, foamagent alkali lignin 40g, waste polyurethane 30g, hardener 100g from the foam strength of 380KPa and low cost.
Design and Development of 850t/h CFB Boiler with Energy Saving Technology
Authors: Ren Xian Hong , Hu Kang Tao , Zhang Jian Chun , Liu Ai Cheng , Yang Hai Rui
Published: January 2014

Taiyuan Boiler Group Co. Ltd. designed and developed an 850t/h CFB boiler with energy saving technology on the principle of “State Specification Design Theory”. By measuring the ash formation and attrition characteristic of the design coal, with the one dimension mass balance model developed by Tsinghua University, the bed quality of the bed inventory and the pressure drop were modified. Based on the particle density calculated, the heating transfer coefficients were chosen and the arrangements of the heating surfaces were modified. According to the special operation conditions of the user, the practical working conditions for the boiler are determined so as to assure the technical characteristics and structural properties in 850t/h CFB boiler.
Test Research on Phase-to-Ground Air-Gap Discharge Characteristics of UHV Substation
Authors: Ye Qi Ming , Xie Liang , Luo Xiao Qing , Huo Feng
Published: January 2014

In order to optimize the design of UHV substation and reduce its construction investment, it is necessary to take further research of UHV substation air-gap discharge characteristics. In this paper, by using sub-conductor and tower to simulate UHV substation air-gap, lightning and switching impulse discharge characteristics tests of UHV substation are taken in the UHV AC test base of SGCC. The results show that, when the distance of conductor between tower is in range of 4m to 7m, the 50% lightning impulse and switching impulse discharge voltage rise along with the rise of air gap distance. As the air-gap increases, the switching impulse discharge voltage presents the trend of saturation. According to the analysis of test results, we can draw a conclusion that the gap factor of switching impulse discharge can be 1.22 when the minimum distance between conductors and tower is 5~8m.
Evaluation of Voltage Sag Mitigation by Resonant Grounding Comparing to Existing Direct Grounding in Provincial Electricity Authority
Authors: Songsiri S. , Sirisumrannukul S.
Published: January 2014

This paper proposes a practical mitigation solution to the voltage sag problem by resonant grounding for a 22-kV distribution system of Provincial Electricity Authority (PEA) at the Patumthani 1 substation in Pathumthani province in Thailand. A computer simulation by ATP-EMTP was carried out to investigate the voltage sag impact at the low voltage side of the delta/wye distribution transformer connected at a fault location in the existing solidly grounded system and proposed resonant grounded system. The results indicate that the proposed resonant grounding can help all customers connected at the same bus survive from voltage sag problems and also keep the customers on the faulty feeder connected to the system being continuously supplied for single-to-ground faults. To evaluate the benefits of the resonant grounding, the different voltage-tolerance curves are proposed by Information Technology Institute Council (ITIC) curve and laboratory testing of Personel Computer (PC) curve, Programable Logig Coltroller (PLC) and Adjustable Speed Drive (ASD). The saving from the cost of customer interruption and voltage sag is calculated comparing between the existing solid grounding and the proposed resonant grounding with different voltage-tolerance curves
New Method to Fabrication 3D Micro-Device Structures
Authors: Emhemmed Adel , Kriama Abdulbast , Terfaas Osama , Green Graham
Published: January 2014

This paper present a new approach for fabricating 3D micro structures based on the elevated structures. The new fabrication method involves combinations of several basic techniques, but a key enabling techniques for the successful development of the fabrication process is combining the photolithography with e-beam lithography processes to create 3-D structures
Simulation of South African Corncob Gasification with Aspen Plus: A Sensitivity Analysis
Authors: Mavukwana Athi-Enkosi , Jalama Kalala , Harding Kevin
Published: January 2014

Biomass is one of the significant fuel sources that can potentially contribute to the worlds energy demands. The most used technology that takes advantage of biomass heating value is still direct combustion which still suffers from significant inefficiencies creating therefore, the need for alternative processes to be analyzed. In this study Aspen Plus simulation package was used to develop a model for the gasification of corncob residues. The effects of equivalence ratio (ER) and steam to biomass ratio (SBR) on syngas composition and gasification temperature were investigated. The results showed that ER values of 0.34-0.35 and SBR values of 0.8 - 1 corresponding to a gasifiers temperature of 854-890°C were the optimum conditions for corncobs gasification.
A Survey on Single-Phase Faulty Line Selection Techniques for Small Current Grounding System in Medium-Voltage Grid
Authors: Tao Yin , Juan Yu
Published: January 2014

Single-phase ground fault line selection problem has never been satisfactorily resolved in small current neutral grounding system in china. According to such a situation and combining theoretical analysis and simulation research with reports published in literature, existing faulty line selection technologies are generalized, and working principles, application conditions and existing defects of these technologies are analyzed, meanwhile the feasible improvement of these technologies and the up-to-date research achievements, and deficiencies of applications in this field are summarized. Finally, the development trend of faulty line selection technology for small-current neutral grounding system is pointed out.
Disturbance Elimination of Buck-Converter with Resonant LPF via ILQ Servo-System
Authors: Shiina Shuhei , Aumted Sidshchadhaa , Takami Hiroshi
Published: January 2014

The proposed optimal control on the basis of both current and voltage of the buck-converter is designed to be based on Inverse Linear Quadratic (ILQ) design method with the resonant low pass filter, which eliminates the disturbance by appended disturbance compensator. The designed scheme is composed of the state equation, an optimal ILQ solution, the ILQ servo-system with the disturbance elimination, the optimal basic gain, the optimal condition, the transfer functions and the disturbance compensator. Our results show the proposed strategy is the stability and robust control and has been made to improve ILQ control for the disturbance elimination of the output response, which guarantees the optimal gains on the basis of polynomial pole assignment.
Gaining the Enthalpy of Solid Yields Formation in the Process of Waste Pyrolysis
Authors: Wijayanti Widya
Published: January 2014

An experimental study of pyrolysis method had been conducted to support the waste-to-energy program. It was very attractive method to convert the waste; cow dung and municipal solid waste in short time, only 2 hours. An appropriate pyrolyzer is required to support this process from the heat transfer mechanism and consider the chemical reaction. Therefore, the study aims to analyze the influence of different temperatures on the measured enthalpy of waste pyrolysis by means of calorimetrical measurement. The waste samples were used in experimental runs, and then the influence of temperature toward the solid yields were investigated. The enthalpy of solid yields formation would be presented by calorific/heating value of formed char/solid yields indicating an important-physical properties of fuel. The results referred that the values of solid yield enthalpy were pointed in a polynomial function indicating endothermic and exothermic reaction during pyrolysis. The different values exhibited that the solid yield enthalpy was also a temperature function, H(T). It ought to replace the H as temperature function in the heat energy balance governing equation. Consequently, the pyrolysis enthalpy could not only assume as endothermic values like in the previous investigations [6,8,1 but also establish both endothermic and exothermic values in globally pyrolysis process.
Numerical Studies on R22 Refrigerant Compressor Using Environment Friendly Working Fluids
Authors: Shreenaath K.G. Sai , Golecha Jigar , Augustin L. Bruno , Suresh M.
Published: January 2014

Vapour compression refrigeration is the most widely used method in domestic and commercial air conditioning and refrigeration systems. R22 (difluoromonochloromethane) is the most widely used HCFC (hydro chlorofluorocarbon) refrigerant in residential, commercial, industrial and transport cooling systems. Montreal protocol in 1987 banned the use of CFCs (chlorofluorocarbon) due to their adverse impact on the environment causing ozone depletion and global warming. HCFCs are also being phased out, though they are less destructive than CFCs. The present work explores compressor performance using alternate environment friendly working fluids so that R22 can be replaced in future. The refrigerants used for the studies are R134a (tetrafluoroethane), R290 (propane) and R600a (isobutane). Compressor performance is analysed by varying refrigerant mass flow rate, evaporator and condenser temperatures and studying their effect on compressor size, power and discharge temperature. A numerical simulation code has been developed in MATLAB using refrigerant properties taken from REFPROP.
Energy Conversion in Compliance of Energy Self-Sufficient Village Program. Case Study: Jarak Village
Authors: Meidiana Christia , Ari Ismu Rini Dwi , Paramita Ema Pratnya
Published: January 2014

The Energy Self-Sufficient Village (ESSV) is one of the main programs from Goverment of Indonesia (GoI) initiated in 2007 and addressed to improve the capability of rural areas to meet the local energy demand from renewable energy. The fulfillment of 60% energy demand is required in ESSV and the source of the energy must be renewable energy. Jarak Village has potentialas to be developed as an ESSV since it has 237 cattles generated manure waste can be converted into biogas. However, the actual conditions showed that the utilization of manure waste as source of biogas is only 14% or about 124,2 kWh covering the energy demand from 40 households. The estimation of the total cattle available in the village can actually covers up to 62% energy demand. The existing numbers of cows generate 82.8 m3 biogas equivalents to 124,2 kWh. Nevertheless, only 124,2 kWh 14% has been consumed by 40 households. It indicates that the consumption of biogas is not optimal. Therefore, the study purposes to evaluate and to estimate the capability of the village to meet the criteria of ESV. With the assumption that there is population growth 0.01%, the criteria of ESV can be fulfilled in 2014. The energy supply of ESV in 2014 is 62%. It indicates that the Jarak Village can actually meet the criteria of ESV in 2014.
Parallel Speed-Up of Preconditioned Fractional Step Navier-Stokes Solvers
Authors: Djanali Vivien , Armfield Steven W. , Kirkpatrick Michael P. , Norris Stuart
Published: January 2014

Parallel performance of a fractional step Navier-Stokes solver is investigated. Parallelisation is performed using Message Passing Interface, with domain partitioning. Block preconditioning is applied to the solution of the pressure Poisson equation, which is often the bottleneck in the computation of the fractional step method. Preconditioners tested are classes of incomplete matrix decompositions and sparse approximate inverses. The computational domain is decomposed into eight parts of about equal size in terms of the number of cells, and solved on eight parallel processors. Several aspects of the parallelisation, such as domain splitting directions, speed-up and scalability of the preconditioners, are discussed.
Thermodynamic Analysis of Ejector as an Expansion Device on Split-Type Air Conditioner Using R410A as Working Fluid
Authors: Sumeru K. , Nasution Henry , Ani Farid Nasir
Published: January 2014

Typically the split-type air conditioner uses a capillary tube as expansion device. To enhance the performance of the system, an ejector can be applied as expansion device to replace capillary tube. Based on the numerical modeling, the coefficient of performance (COP) of standard cycle using R410A as working fluid was slightly lower than that of R22. The use of an ejector as an expansion device on a split-type air conditioner using R410 increased the COP by 10.8%. Also, R410A has a lower total GWP impact compared with R22, which reduce negative impact on the environment.
Reduction of Energy Losses in the End Wall Junction Area through the Addition of Forward Facing Step Turbulent Generator
Authors: Mirmanto H. , Sutrisno Sutrisno , Sasongko Herman , Noor D.Z.
Published: January 2014

The research is conducted in order to reduce energy losses caused by the secondary flow in the endwall junction. This phenomenon is caused by the interaction of two adjacent viscous flow (symmetric airfoil and endwall). Reduction of energy loss carried out by addition of Foward Facing Step Turbulator (FFST) in the upstream. Endwall junction area is modeled as a NACA 0015 airfoil and a flat plate. Position of FFST is at a distance L = 2/3 C upstream leading edge and a thickness d = 4% C. Free stream conditions Red = 105 with turbulence intensity (Tu) 5%. Research is conducted by numerical and experiment methods. Pathlines of numerical result methods has an identic structure with "Oil Flow Visualization" of the experiment.Result of the research states that the addition of FFST can increase the turbulence intensity in the flow near the wall. So at the same angle of attact (α), the saddle point position on the leading edge has distance nearly the same but a little more towards the lower side and the separation line is wider than without FFST. Because the flow has stronger turbulence intensity, attachment line of the upper and lower sides have a better capability of following the contours of the body. So the point of separation can be delayed and blockage (energy loss) can be reduced as well. Reduction of energy loss is most effective on α=8 ° (4.16%),Keyword : Secondary flow, forward facing step, turbulent intensity.
CFD Simulation of Heat Transfer in Fluidized Bed Reactor
Authors: Winaya I. Nyoman Suprapta , Putrawan I. Made Agus , Sujana I. Nyoman Gede , Sucipta Made
Published: January 2014

This study aims to predict heat transfer from a heated bed in a gas fluidized bed using Syamlal-OBrien drag coefficient. Discrete particles model with the Navier-Stokes equation and Eulerian multiphase are used to approach heat transfer simulation. Coefficient of heat transfer which is related to Nusselt Number and volume fraction are calculated using Gunn model which was compiled from C++ program language. The effect of fluidization velocity variation on the heat transfer coefficient comes to the fore, indicating the heat transfer and solid volume fraction at the bed height are very dependent. Contour of solid volume fraction and temperature distribution are also presented.
Design Online Artificial Gain Updating Sliding Mode Algorithm: Applied to Internal Combustion Engine
Authors: Priyanto Agoes , Nekooei Mohammad Javad , Jaswar Jaswar
Published: January 2014

This paper presents an online Artificial Fuzzy sliding Gain Scheduling Sliding Mode Control (AFSGSMC) design and its application to internal combustion (IC) engine high performance nonlinear controller in the presence of uncertainties and external disturbance. The fuzzy online tune sliding function in fuzzy sliding mode controller is based on Mamdanis fuzzy inference system (FIS) and it has multi input and multi output. The input represents the function between sliding function, error and the rate of error. The output represents the dynamic estimator to estimate the nonlinear dynamic equivalent in supervisory fuzzy sliding mode algorithm. The performance of the AFSGSMC was compared with the IC engine controller based on sliding mode control theory (SMC). Simulation results signify good performance of fuel ratio in presence of uncertainty and external disturbance
Thermal Stress Intensity Factors of Crack in Solid Oxide Fuel Cells
Authors: Anam Khairul , Lin Chih Kuang
Published: January 2014

Structural durability is the main focus of solid oxide fuel cells (SOFCs) development which is affected by the thermal stress caused by considerable CTE mismatch between components and thermal gradient. In this paper we investigate the thermal stress intensity factor for mode I, mode II and mode III of positive electrode-electrolyte-negative electrode (PEN) at room temperature and steady stage for an initial crack size of 10 μm. A commercial finite element analysis (FEA) was used to find the highly stressed regions in PENs and calculate the thermal stress intensity factors. The stress distributions are calculated at uniform room temperature and at steady stage with a non-uniform temperature profile. The thermal stress intensity factors are calculated for various principal directions at the location having the greatest maximum principal stress at room temperature and steady stage. The critical stress regions are identified based on the maximum principal stress at room temperature and steady stage. The maximum principal stress is of 53.45 MPa and 45.12 MPa in principal direction of-43.97° and-42.37° at room temperature and steady stage, respectively. The mixed-mode stress intensity factor including mode I, mode II, and mode III is calculated due to multi-axial thermal stresses. However, the stress intensity factor for mode I have a highest value compared to those for modes II and III. The principal direction has an effect on the thermal stress intensity factor for the critical region with the greatest maximum principal stress. All the calculated stress intensity factors in the present study are less than the corresponding fracture toughness given in the literature, ensuring the structural integrity for the given planar SOFC stack.
Structural Analysis of a Tracking Photovoltaic System with a Pedestal Solar Tracker
Authors: Lin Chih Kuang , Dai Chen Yu
Published: January 2014

The structural integrity and deformation-induced misalignment of solar radiation for a tracking photovoltaic (PV) system under self-weight is investigated using a finite element analysis (FEA) approach. Gravity is applied to calculate the stress distribution and structural deformation. Misalignment of solar radiation induced by structural deformation is also calculated. Moreover, to avoid damages caused by resonance, natural frequencies of vibration for the given tracking PV system are also determined. Strain changes are measured experimentally at two selected locations in the given solar tracker during field operation for comparison with the simulation results. A reasonable agreement between the simulations and experimental measurements is found such that the constructed FEA model is validated to be effective in assessment of the structural integrity for PV systems under self-weight. No structural failure is predicted for all components in the given solar tracker under the given loading condition according to the von Mises failure criterion. An agreement in the trend of variation of misalignment and resultant displacement of PV modules is found. Considering the effect of self-weight only, the maximum misalignment of solar radiation is of 0.275o at elevation angle of 45o when rotating the solar tracker from 0o to 75o. It is expected that such a misalignment value will not cause a significant degradation of power generation for a PV system. The range of natural frequencies of the first six vibration modes for the given PV system is from 3.85 Hz to 11.4 Hz.
New Polyhedral Elements Based on Virtual Node Method for Solid Mechanics and Heat Transfer Applications
Authors: Perumal Logah , Fadhel M.I.
Published: January 2014

Finite element method (FEM) is a well-established method and commonly utilized to solve complex engineering problems which cannot be solved analytically. Various element types have been formulated over the years to facilitate engineering analyses using FEM. In this paper, new polyhedral elements are developed by utilizing virtual node method. This paper covers the formulation of shape functions and integration schemes for the new polyhedral elements. These new polyhedral elements have advantages due to the nature of their shape functions which consist of monomials uavbwc. Integration of functions within the element can be accomplished by utilizing an exact integration technique. These polyhedral elements can be utilized to solve real 3 dimensional problems which arise in solid mechanics and heat transfer phenomena.
Interaction between a Crack and an Isotropic Tri-Material Media in Anti-Plane Elasticity
Authors: Wikarta Alief , Chao Ching Kong
Published: January 2014

Solution of a crack interacting with a tri-material under a remote shear load for anti-plane elasticity problem is considered in this paper. The main purpose of this work is to study the interaction between a crack and a tri-material for anti-plane elasticity problem. This can be achieved by determination of the stress intensity factors that allow the characterization of this interaction from the point of view of linear elastic fracture mechanics. The proposed method is based on complex variable solution of a screw dislocation together with logarithmic singular integral equations. The singular integral equation is then solved numerically by modeling a crack in place of several segments. Some numerical results are performed to show the effects of material property combinations and geometric parameters on the normalized mode-III stress intensity factors. The results show that the stiffer materials may always give retardation effect on stress intensity factors when a crack approaching interfaces. On the other hand, the softer materials may always give enhancement effect on stress intensity factors.
Designing and Prototyping Surveillance Robot with Self-Protection Using Nail Gun
Authors: Sebastian Novandri , Erwin Erwin , Listijorini Erny , Dwinanto Dwinanto
Published: January 2014

Designing and manufacturing / prototyping surveillance robot that has self-protection mechanism by using nail gun with VDI (Association of German Engineers) method, aims to design and create a robot that capable to conduct reconnaissance missions and protect themselves as well as immobilize the target object. The prototype robot is able to send data in the form of audio and visual through Wireless system by using Wi-Fi (Wireless Fidelity). The robot is equipped with self-protection system such as nail gun that can move in rotation and elevation, it is such an effective weapon to paralyze the targets objects if necessary. This robot is designed to maneuver on the field that has tilt angle up to 30o. Based on the test results, the robot is able to maneuver with speed 2.88 km/h on duration more than 30 minutes and be able to pass the field angle of 35o. Proximity sensors which are used as indicators of arm robots position works well on the pitch and yaw motion. Security system that is designed to shoot also works well. The most effective control radio frequency used is 2.4 GHz and the data sender system frequency is 5.8 GHz.
Numerical Modelling of the Initial Stress and Upward Deflection of Glulam Beams Pre-Stresseed by Compressed Wood
Authors: Anshari Buan , Guan Zhong Wei
Published: January 2014

A new approach to reinforce glulam timber beams has been developed by using compressed wood (CW) which is made of a lower grade wood through densification processes. In the reinforcing practice, compressed wood blocks are inserted into pre-cut holes on the top of glulam beams to produce pre-camber and to generate initial tensile and compressive stresses on the top and the bottom extreme fibre of the glulam beam. In order to optimize the size, the number and the location of CW blocks, 3-D finite element models have been developed. 3D non-linear finite element models have been developed to simulate the pre-camber of Glulam beams locally reinforced by compressed wood blocks. The models developed have also produced the initial tensile and compressive stresses at the top and bottom extreme fibres with building-up moisture-dependent swelling on the CW blocks. With the pre-camber and the initial stress state that cancel out proportions of working deflection and stresses.
Preliminary Numerical Study on Designing Navigation and Stability Control Systems for ITS AUV
Authors: Herlambang Teguh , Nurhadi Hendro , Subchan Subchan
Published: January 2014

In this paper, the numerical study of designing on navigation and stability control system for AUV is studied. The study started by initiating hydrostatic forces, added masses, lift force, drag forces and thrust forces. Determining the hydrodynamic force which is the basic need to know the numerical case study on designing on navigation and stability control system for AUV where Autonomous Underwater vehicles (AUV). AUV is capably underwater vehicle in moving automatically without direct control by humans according to the trajectory. The result of numerical study is properly to be the reference for the next developing for AUV.
Actuator Power Consumption of Active Suspension System with Override Control Strategy
Authors: Wasiwitono Unggul Wasiwitono
Published: January 2014

The main function of the vehicle suspension is to improve ride and handling performance. In vehicle active suspension, better ride comfort is usually required larger control input and larger suspension deflection. However, the actuator that deliver the control signal have a limitation which is commonly known as actuator saturation. There is also a structural constraint that limits the suspension deflection. In this study, an alternative approach to the vehicle active suspension system is proposed. In this approach, some separation in the controller such that one part is devoted to achieve nominal performance and the other part is devoted to constraint handling is performed. In addition, the actuator power consumption of the proposed control strategy is further investigated numerically. The simulation results show that the proposed control strategy can manage the trade-off between performance and the actuator power consumption.
Trailing Edge Deformation Mechanism for Active Variable - Camber Wind Turbine Blade
Authors: Kosasih Bu Yung , Dicker Michael
Published: January 2014

Blade root fatigue stress, primarily resulting from wind shear and turbulence, is a critical factor in wind turbine design. Blade mounted aerodynamic control devices have been shown to have the potential to reduce this. However, limited research exists into suitable devices, with great challenges being involved in meeting the requirements for use on large turbines. The blade designed in this work addresses this by employing a piezoceramic actuated compliant mechanism, contained within a flexible matrix composite structure. The resulting mechanism design achieves a sectional change in lift coefficient of ΔCL +0.4 to 0.15. The performance of the blade is analysed with a quasi-steady time marching BEM model, employing optimal control. A reduction of 21.59% in the standard deviation of the flap-wise bending moment was achieved, a comparable result to previous load control investigations.
The Emergy Value Assessment of Municipal Waste Management in Yogyakarta, Indonesia
Authors: Meidiana Christia
Published: January 2014

The emergy values of three different scenarios for the new landfill in Yogyakarta City were calculated to evaluate the sustainability and efficiency. The assessment included the environmental parameters which are Environmental Yield Ratio (EYR), Net Emergy, Environmental Loading ratio (ELR) and Emergy Sustainability Index (ESI).The calculation of emergy indices showed that treatment in landfill requires the largest emergy input for all scenarios with the percentage between 92% and 97%. Scenario 0 contains the lowest total solar emergy implying that it requires lower emergy input compared to other scenarios. Scenario 1 needs the lowest emergy investment. Meanwhile, Scenario 2 offers the highest emergy recovery contributed mainly by the output from higher scavenging rate. Scenario 2 is the best option for the municipal waste management in Yogyakarta since it meets more criteria for sustainability and efficiency.
Experimental-Based TGPID Motion Control for 2D CNC Machine
Authors: Nurhadi Hendro , Subowo Subowo , Hadi Syamsul , Mursid Mahirul
Published: January 2014

2D (two-dimensional) motion is the basic motion for computer numerical controlled (CNC) machine in all industrial applications. In this paper, it is aimed to optimize the multi-performance characteristics, namely roundness error determined by best-fit-circle (REB), actual radius (R_act) and position time (Tt) that is the time needed for making a circular motion. By applying a Taguchi Grey Proportional Integral Derivative (TGPID) control method, the performance of this 2D multi linear motion is improved. The roundness error is closed to zero as time went to infinity which means the actual radius is closed to the reference radius. The position time differences (dTt) of X and Y axis for circling is also zero. This indicated the TGPID approach is robust.
Optimization of Tool Wear, Surface Roughness and Material Removal Rate in the Milling Process of Al 6061 Using Taguchi and Weighted Principal Component Analysis (WPCA)
Authors: Ulfiyah Laily , Pramujati Bambang , Soepangkat Bobby Oedy Pramoedyo
Published: January 2014

In the metal cutting industry, end milling has an important role in cutting metal to obtain the various required shapes and size. This study takes Al 6061 as working material and investigates three performance characteristics, i.e., tool wear (VB), surface roughness (Ra) and material removal rate (MRR), with Taguchi method and WPCA for determining the optimal parameters in the end milling process. The performance characteristic of MRR is larger-the-better while VB and Ra are having smaller-the-better performance characteristic. Based on Taguchi method, an L18 mixed-orthogonal array was chosen for the experiments. The optimization was conducted by using weighted principal component analysis (WPCA). As a result, the optimization of complicated multiple performance characteristics was transformed into the optimization of single response performance index. The most significant machining parameters which affected the multiple performance characteristics were type of milling operation, spindle speed, feed rate and depth of cut. Experimental result have also shown that machining performance characteristics of end milling process can improved effectively through the combination of Taguchi method and WPCA.
Multiple Performance Characteristics Optimization in the Turning Process of AISI H13 Tool Steel Using Taguchi and Fuzzy Logic
Authors: Soepangkat Bobby Oedy Pramoedyo , Pramujati Bambang , Karuniawan Bayu W.
Published: January 2014

This paper presents the application of Taguchis method of orthogonal array and signal to noise ratio with logical fuzzy reasoning for multiple output optimization of turning AISI H13 steel using carbide tool. The cutting parameters, i.e., cutting speed, feed rate, depth of cut and nose radius, are optimized with considerations of multiple performance characteristics such as cutting force, feed force, surface roughness and tool flank wear. Experimental results are provided to illustrate the effectiveness of this approach.
Numerical Simulation of Multipoint Forming with Circular Die Pins in Hexagonal Packing
Authors: Rivai Wardhani , Suwarta Putu , Sanjoto Budi Luwar , Nur Husodo , Hari Subiyanto
Published: January 2014

Multipoint forming (MPF) in flexible forming technology. from the previous research of multipoint forming, the configuration of the upper and lower punch matrices were configured in square packing. In this paper, model of multipoint forming configuration was developed and the numerical simulation was performed to investigate the influence of the proposed pins arrangement, hexagonal packing. The packing density in hexagonal arrangement is higher than in square one. The deformation process in multipoint forming with hexagonal packing is evaluated in terms of stress and strains distribution. The results demonstrated that forming tool with hexagonal packing is more efficient than pins arranged in square packing. But dimples and wrinkles as the typical defect of multipoint forming was inevitable consequences of discontinuous contact between the punches and workpiece, appeared. The dimpling phenomenon is more present in MPF with hexagonal packing than with square packing.
Sol-Gel Synthesis of Zn Doped HA Powders and their Conversion to Porous Bodies
Authors: Naqshbandi Abreeq , Sopyan Iis , Gunawan Gunawan , Suryanto Suryanto
Published: January 2014

The present study was aimed at fabricating porous ceramic scaffolds via polymeric sponge method for biomedical applications using as synthesized Zinc doped Hydroxyapatite (ZnHA) powders. Zn doped HA powders were prepared via sol-gel method using diammonia hydrogen phosphate [(NH4)2HPO4] and calcium nitrate tetrahydrate [Ca (NO3)2.4H2 as starting materials. The obtained powders were then used for the preparation of porous ZnHA scaffolds via polymeric sponge method. The green porous bodies so developed by impregnating cellulosic sponges with HA slurries, were subjected to sintering process at a temperature of 1300 Field-emission scanning electron microscopy (FESEM) was used to observe the surface morphology of the powder and sintered porous sample. The structure and crystallinity of (Zn)HA powder and the sintered porous samples was analyzed using X-ray diffractometer whereas Fourier transform infrared spectroscopy (FTIR) was used to determine the presence of various phases in the powder. FESEM results showed the formation of agglomerates at an increased Zn concentration. The morphology of the porous samples showed high degree of fusion and densification with an increase in Zn concentration. Preliminary mechanical testing results show that maximum compression strength of HA porous bodies was 0.12 MPa.
Flow Visualization Pattern on Sharp Edge T-Junction through Dividing Flow Channel
Authors: Lukiyanto Y.B. , Wardana I.N.G. , Wijayanti Widya , Choiron M. Agus
Published: January 2014

In the previous study, sharp edge T-junction had been investigated to determine head losses and flow pattern. In this study, sharp edge T-junction was used as inlet flow model scale to determine flow visualization pattern. The apparatus test provide a dividing flow channel on static conditions which is the inlet pressure larger than 1 atm. Pressure difference is measured by using a U-pipe manometer. The manometer was inserted between inlet and outlet. Flow rate is measured by collecting fluid into a measuring cup. The coefficient of losses is determined as a result for predicting the losses energy. Flow Visualization Pattern is one of solution to perform the mechanism of sharp edge T-junction as inlet flow model scale. The result shows that flow pattern from simulation has the same trend with experimental results.
Dielectric Properties for the Ring Opening Polymerisation of ε-Caprolactone
Authors: Kamaruddin Mohd Johari , Ahmad Zaini Muhammad Abbas , Johari Anwar , Tuan Abdullah Tuan Amran
Published: January 2014

A dielectric property study was performed across a wide range of frequencies and temperatures onring opening polymerisation of ε-caprolactone system in order to relate quantitatively their dielectric properties to microwave heating mechanisms. An analysis of the results concluded that heating mechanism of the polymerisation mixtures in a microwave field was controlled by the dielectric properties of monomer, where the monomer was the major component (>90 % volume/volume) as well as the component with highest dielectric loss and dissipation factor. The penetration depth of mixtures at 2.45 GHz was noted to increase from ~0.58 cm (at 20 C) to ~3.3 cm (at 150 °C). This small penetration depth limits the potential to achieve the successful scale up of a microwave-assisted polymerisation of ε-caprolactone in batch mode at 2.45 GHz. As a result, this will lead to inhomogeneous bulk temperature distribution within the polymerisation mixture and irreproducible chemistry. However, a fast heating rate based on a high value of dissipation factor and dielectric loss of the polymerisation mixtures shows potential to enable the reaction to be completed in a few seconds that may allow the polymerisation to be transferred to a continuous flow process. In so doing, small diameter tubular reactors can be employed hence removing this penetration depth issue. Thus, the polymerisation mixtures dielectric properties are worth to be considered to ensure the reliability and reproducibility of the microwave assisted synthesis of poly-ε-caprolactone at large scale production.