bluuebunny/crossref_metadata_2025 huggingface dataset:
Study on Rheological Properties of Polylactic Acid Retardant System
Authors: Li Dong Ze , Jia Xiao Chuan , Lu Xiu Ping , Zhai Sheng Jia
Published: January 2014

A series of polylactic acid (PLA)/IFR composites was prepared by melt blending method.Capillary rheometer and rotary rheometer were applied to investigate the effects of and flame retardants on rheological properties. The results of the rheological test show that the melt flow rate increases with the increasing of content of Intumescent flame retardant. Intumescent flame retardant joined making PLA system flow rate is larger than pure PLA, melt flow rate increases, apparent viscosity decreases, relaxation time decreases, and the complex viscosity decreases gradually with the increase of scanning frequency.
The Abrasion Test Study of Fly Ash Pavement Concrete in Cold Areas
Authors: Man Du La
Published: January 2014

Based on the freeze-thawing cycle characteristic of road concrete in cold climatic condition. The objective of this paper was to estimate the practicality of using fly ash discharged from a coal fuel electric plant in Inner Mongolia in concrete pavements. The abrasion resistance of road concrete containing fly ash was studied after suffering freeze-thawing cycles. The results indicate that the coarse aggregates were exposed after freeze-thawing cycle test and the replacement ratio of fly ash has little influence on the abrasion resistance.
Study on Selection of the Length of Reinforced Concrete Segment for Oil and Gas Shield Tunnel with 3D Numerical Analysis
Authors: Wang Xiao Feng , Zhou Xiao Jun , Hu Hong Yun
Published: January 2014

3D finite element analysis is utilized to calculate stress and internal forces in three different lengths of reinforced concrete segment for oil and gas shield tunnel subject to water and earth pressure by means of load-structure model. The rational length of concrete segment is determined to be 1.2m long after comparing the calculated stress and internal force in concrete segment with length of 1.0m, 1.2m and 1.5m respectively. Meanwhile, the safety factor is also compared in order to determine the rational length of concrete segment. The analysis shows that segment length for oil and gas shield tunnel with small cross-section should be less than 1.2m so as to facilitate its transportation and erection on construction site.
Three-Dimensional Finite Element Analysis for Concrete Gravity Dam of Shachang Reservoir
Authors: Ji Dong Yu
Published: January 2014

Through analyzing concrete gravity dam structures mechanical characteristics in construction process and operating process, this paper adopts finite element method to carry out structural analysis for concrete gravity dam of Shachang reservoir. Deducing distribution law of the dams stress and displacement in construction process and operating process. Analysis results show that, concrete gravity dam of Shachang reservoir is reasonable, it meets the requirements for design. The analysis results provide a certain reference for design and construction of concrete gravity dam structure.
Finite Element Simulation Analysis of Concrete Hyperbolic Arch Dam
Authors: Ren Zhen
Published: January 2014

Arch dam is a water retaining structure which has beautiful bodily form and reasonable structure form, in recent years, arch dam has been widely used. This paper adopts finite element method to carry out three-dimensional finite element simulation analysis for Haierwa reservoir concrete hyperbolic arch dam, researching variation law of the dams stress and displacement in operating process. Research results show that, Haierwa reservoir concrete hyperbolic arch dam is reasonable structure, good mechanical performance, every index meets the requirements for design.
Production Process and Technology Development of Hot-Dip Galvanizing
Authors: Cai Xing Fu , Huang Yong Zhi , Li Yun Gang , Zhao Li Na
Published: January 2014

Development process of Hot-dip galvanizing technology and characteristics of different production methods were reviewed in this paper. Presently, the UEC method was utilized widely because of its advantages like high output, high quality, energy saving, lower consumption and low products cost. To improved the corrosion resistance of the coating and declining the cost of hot-dip galvanizing, hot-dip galvanizing alloyed coating has been developed. Although the general hot-dip galvanizing has been developed rapidly in China, we should make great efforts to research deeply and improve the hot-dip galvanizing technology, especilly in the areas such as zinc alloy plating and the corresponding hot-dip galvanizing technology.
Application of Wavelet Transform in Stochastic Loading Characteristics Analysis
Authors: Bai Quan , Liu Zi Xin , Han Jing Jing , Jin Sheng Ji , Yu He
Published: January 2014

Understanding the characteristics of stochastic loading is the premise and foundation for structure analysis. Traditional amplitude spectrum and power spectral density (PSD) method based on Fourier transform (FT) has limitation, that is, it loses any information with time and can not reflect the non-stationary characteristics of stochastic loading. Wavelet transform possesses assembling ability in both time and frequency domain,and it possess stronger ability of analyzing non-stationary signal. In this paper, the method of estimating PSD and time-dependent PSD of stochastic loading using wavelet transform is researched. The calculating process is programmed and the method is validated by a numerical example. The analysis result of example indicates that the method presented in this paper is feasible.
The Symmetry in the Traditional Chinese Architecture
Authors: Tang Xiao Xiang , Chen Chun Jiao
Published: January 2014

The symmetry is a remarkable aesthetic characteristics in the traditional Chinese architecture. Through analyzing the different manifestations of symmetry in the settlement planning, in the construction of the architectural settlements, in the arrangement of the building complexes and in the structures of single building and its decorations, the paper explores it as an aesthetic technique and a cultural carrier bearing the traditional Confucianism, Daoism, peoples ideals and wishes, and proposes to reconsider its cultural connotation and significance in the modern architectural design as well as the social life, achieving the balance and harmony outside and inside of ourselves.
The No-Load Voltage Waveform and Damper Bar Temperature Computation of Integral Number Slots Large Hydro-Generator which the Number of Damper Bars per Pole Increased
Authors: Yang Ru , Li Hong Jun , Fan Zhen Nan
Published: January 2014

In order to analyze the no-load voltage waveform and damper bars temperature of integral number slots large hydro-generator which the number of damper bars per pole increased, the 2D moving electromagnetic field-circuit coupling model of a 600MW integral number slots hydro-generator and 3D temperature field FE model of the rotor are established, and the no-load voltage waveforms and temperature are calculated. The research is helpful for improving design standard and enhancing the operation reliability of the large hydro-generator and electric network.
Numerical Simulation of Ultrasonic Shear Wave Propagation Based on the Finite Element Method
Authors: Ma Jian , Zhao Yang , Sun Ji Hua , Liu Shuai
Published: January 2014

The present paper provided a kind of numerical simulation method which was employed to guide the process of ultrasonic nondestructive testing and analyze the inspection results. The simulation concerning the propagation process of shear wave in the steel plate was carried out using the ANSYS, according to the mechanism of ultrasonic mode conversion. Then, the frequency, velocity and refraction angle were extracted from the time-domain date in order to verify the simulation. It is found that the result of simulation agrees well with the theoretical one, which shows that the present method is correct and reliable.
Research on Low-Temperature Reliability of Electrical Connectors
Authors: Luo Yan Yan , Wang Yi Jun , Liu Lei , Liu Xin Wei , Ma Zhen Ping , Wang Zhen , Zheng Shu Mei
Published: January 2014

This paper mainly studies the effects of low temperature on the reliability of electrical connectors. Based on the theory of constant stress accelerated life test, this paper provides a kind of scheme of low temperature reliability test, which includes magnitude of the temperature stresses, the parameters measured during the test and so on. The detecting circuit is designed; the test is carried out and finally, according to the experimental data, it can be concluded that 1) both the absolute change and the relative change of contact resistance are small for each temperature stress; 2) the forecast data show a tendency toward slightly lower value of contact resistance for each low temperature stress; 3) the lower the test temperature stress, the smaller the value of contact resistance, but the difference in contact resistance is tiny; 4) stress analysis of samples under low temperature is also helpful for correctly evaluating the effects of low temperature on the reliability of electrical connectors.
Synthesis of Ni0.6Cu0.4Fe2O4 Ferrite Fine Powder Using Egg White Method
Authors: Wang Lei , Li Zhi Dong , Liang Yin , Zhao Kun Yu
Published: January 2014

Polycrystalline ferrites powders samples: Ni0.6Cu0.4Fe2O4 were synthesized by using metal nitrates and freshly extracted egg white, all the samples were sintered at 500°C,520°C, 550°C, 580°C and 600°C for 3h,6h,9h, respectively. The better synthesis conditions were investigated by analyzed the effect of sintering temperature and soaking time on structural, grain size and magnetic properties using X-ray diffraction (XRD), laser grain size analyzer (LPSA) and vibrating sample magnetometer (VSM). From the above analysis, the better synthesis conditions is set two insulation work steps: First at 240°C for 1h, then heating to 440°C for 2h, finally sintering at between 520°C and 550°C for 6h.
Controlled Morphologies of Nanostructured ZnO Films by MOCVD Method
Authors: Ahmmad Bashir , Kanomata Kensaku , Hirose Fumihiko
Published: January 2014

Metal-organic chemical vapor deposition (MOCVD) method has been applied to grow nanostructured ZnO films on Si (100) substrate at temperatures ranging from 200 to 550 °C. The as-prepared films were characterized by XRD, SEM, XPS analysis. The growth rate of ZnO films increases with increasing the deposition temperatures. The deposition temperatures have a drastic effect on the crystallinity and morphology of the nanostructured ZnO. Whisker shaped ZnO is formed at a temperature of 350 °C. The deposition time also affects the morphology of the particles. At 400 °C, sample with one hour deposition forms whisker shaped ZnO nanostructures whereas that of with two hours deposition forms flower-like nanostructures.
Back-EMF Position Detection Technology for Brushless DC Motor
Authors: Wu Hong Xing , Qi Zhi Yuang , Zheng Ji Gui , Zhou Shou Ming
Published: January 2014

Without position sensor control technology of brushless DC motor has become the focus of many experts and scholars at home and abroad. The article presented research of without speed and position sensor control for brushless DC motor, including brushless DC motor mathematical model, Back-EMF detection principle and starting position detection method, and designed a hardware control system based dedicated digital signal processor (DSP). For experimental study of the system based experimental prototype had shown: this method can achieve no load starting, load starting and load operation of without position sensor brushless DC motor.
PerformanceAnalysis of Integrated Solar Combined Cycle Power Plant for Dhahran, Saudi Arabia
Authors: Sanusi Yinka Sofihullahi , Gandhidasan Palanichamy , Mokheimer Esmail M.A.
Published: January 2014

Saudi Arabia is blessed with abundant solar energywhichcan be use to meet its ever increasing power requirement. In this regard, the energy analysis and plant performance of integrated solar combined cycle (ISCC) plant with direct steam generation (DSG) was carried out for Dhahran, Saudi Arabia using four representative months of March, June, September and December. The plant consists of 180MW conventional gas turbine plant and two steam turbines of 80MW and 60MW powered by the solar field and gas turbine exhaust. With high insolation during the summer month of June the plant can achieve up to 25% of solar fraction with ISCC plant efficiency of 45% as compared to gas turbine base of 38%.This can however be improved by increasing the number of collectors or/and the use of auxiliary heater .
Effect of Temperature Cycling on Stress Relaxation Behavior of Electrical Connector Contacts
Authors: Luo Yan Yan , Wang Li Xin , Li Ke , Lei Ming Ming , Liu Guo Jin , Liu Hong Xun , Li Xiao Ning , Ren Yong Long , Zhang Xiao Jun
Published: January 2014

This paper mainly studies the effect of temperature cycling on stress relaxation behavior of contacts for electrical connectors. Based on the analysis of the test specifications of electrical connectors, this paper provides a kind of test method on stress relaxation behavior of electrical connector contacts under temperature cycling conditions. The detecting circuit is designed; the test is carried out and finally, according to the test data, it can be concluded that 1) for the same temperature change, the absolute change of strain within the temperatures above zero is bigger than that within the subzero temperatures; 2) the deformation of contacts gradually increases as the number of cycles increases. The length of the degradation process for electrical connectors might be related with the high temperature value, temperature variation or temperature variation rate.
Validation of AWTSim as Aerodynamic Analysis for Design Wind Turbine Blade
Authors: Wiratama I Kade
Published: January 2014

This paper presents the results of validation AWTSim code and this code has been used to analyze aerodynamic performance in the optimization design blade wind turbine. The validation was performed to know the accuracy of AWTSim code compared to WT_Perf by using the test wind turbine blade AWT-27. Blade AWT-27 was taken as the case for all through of this study and the design pitch angle for blade AWT-27 was 1.2° to stall (-1.2). However, in order to compare the results with available results, pitch angles 0, 1 and 2 degrees to stall were considered for simulation. The results of validation show that the predicted power curve, power coefficient and thrust by two codes are almost similar or less than 1%.
Redesign ITS Central Library through Smart Building
Authors: Junaidi Muhammad , Parindra Kusriantoko , Ardhyananta Hosta , Bachtiar Ary , Dimas Anton A.
Published: January 2014

Energy conservation is one of many technique applied to reduce the global warming effect. Sepuluh Nopember Institute of Technology (ITS) contributes to encourage energy conservation by ITS Eco Campus programs. It has so many activities, one of them is audit energy as one way to get energy efficiency in educational area. ITS central library is most accessable building both student and other academics community with total area more than 400 square matres and high occupation rate approximately 90% everyday. Energy audit techniques were carried out by an energy audit team to identify any energy conservation opportunities (ECOs). walk-through assessment and data analysis were conducted over all building zones. These levels of assessments proved that the building and its mechanical and electrical systems were improperly maintained and inefficiently operated. So that, ITS Central Library will be redesigned to be smart building by improving light intentensity level, humidity, and room temperature appropriate with ASHRAE90.1-2005. Thus exterior building like wall, glass, roof and floor will be redesigned to emphasize minimum total load. Replacement single glass to double glass reduce the load conduction and radiation through glass, approximately 2,7%.
Experimental Study on the Effect of Reynolds Number Variation on Drag Force for Various Cut Angle on D-Type Cylinders
Authors: Pudjanarsa Astu , Ardawalika Ardian
Published: January 2014

Experimental study on the effect of Reynolds number variation on drag force for various cut angles on D-type cylinders was performed. Five different cut angles on different cylinders were applied including: 35o, 45o, 53o, 60o, and 65o. The free stream velocity was varied so the Reynolds number also varied.The experiment was carried out at a subsonic wind tunnel. Drag force for a cut D-type cylinder (for example 35o) was measured using a force balance and wind speed was varied so that corresponding Reynolds number of 2.4×104÷5.3×104 were achieved. Wind turning angle was kept at 0o (without turning angle). This experiment repeated for other D-type cylinders.Experiment results show that, for all D-type cylinders, drag force decreased as the Reynolds number increased, then it was increased after attain minimum drag force. For all D-type cylinders and all variations of Reynolds number the drag minimum is attained at cut angle of 53o. This value is appropriate with previous experiment results.
Reactive Mixing Behavior of the Nitration of Glycerin in a Stirred Vessel at Various Perturbation
Authors: Wulandari Retno , Wardana I.N.G. , Wahyudi Slamet , Hamidi Nurkholis
Published: January 2014

Mixing processes are best understood in turbulent flows, where, ironically they are only understood in a statistical sense. Similarly, detailed analysis of the mechanisms of the realistic mixing process in deterministic laminar flows is nearly absent from literature. This experiment was implemented to investigate the comparable performance of reactive mixing at various perturbation; including continuous, periodic and chaotic. The experiment was designed to reveal the effects of perturbations on glycerin dissolution in nitric acid in stirred vessel. The ratio of glycerin (C3H5 (OH)3) to nitric acid (HNO3) is 1 : 3. The geometrical parameter was set to R1/R2 = 37.5/7, and an eccentricity of ε = 18.75 mm. The mixing time for dissolving fixed amounts of glycerin in fixed amounts of nitric acid was measured and compared to those from several different perturbations. It was found that mixing time for the exothermic reaction of glycerin nitration had been influenced by perturbations applied to fluid mixing. Comparable experiments have shown that mixing time in the glycerin-nitration reaction could be changed dramatically, along with various perturbations. This experiment results explicitly demonstrate the benefits of mixing performance from chaotic perturbations.
Production of Ethanol as a Renewable Energy by Extractive Fermentation
Authors: Widjaja Tri , Altway Ali , Permanasari Ayu Ratna , Gunawan Setiyo
Published: January 2014

One issue with batch fermentation is that product inhibition causes low yields and ethanol productivity. The objective of this study was to increase the yield and ethanol productivity via continuous fermentation in a packed bed bioreactor with both an integrated extraction process and recycling of the raffinate into the fermenter. Molasses was used as the feedstock, and the immobilized cells were supported by ĸ-carrageenan. This process used n-amyl alcohol, 1-octanol, and 1-dodecanol as solvents. The yield and ethanol productivity increased from 8.79% to 20.03% and 34.54 g/L·h to 118.16 g/L·h for experiments using n-amyl alcohol, 9.05% to 12.67% and 35.59 g/L·h to 74.71 g/L·h, for 1-dodecanol, 8.89% to 13.45% and 34.93 g/L·h to 84.62 g/L·h, for1-octanol by increasing recycle ratio from 0 to 0.5. Based on these results, n-amyl alcohol was the best solvent for the extractive fermentation process.
Modular System for Testing the Performance of Poly-Articulate Robotic Structures
Authors: Contoloru Violeta Cristina
Published: January 2014

This paper presents a modular system for testing the performance of a poly-articulate robotic arm (snake like) with the push-pull actuation redundancy. Mechanical structure contains modules that allow testing of robots with different structures of the robotic arm (discrete hyper-redundant, continuous). Sensory system can be configured depending on the product and testing program adapting the sensors of position, velocity, time and vibrations. The monitoring system developed allows the automatic calibration of actuators and sensors, data and signal acquisition.
Air to Air Ejector with Various Divergent Mixing Chambers
Authors: Dvořák Václav
Published: January 2014

The article deals with experimental investigation of subsonic air to air ejector with various configurations of the mixing chamber and the diffuser. A constant mixing chamber, 2° and 4° divergent mixing chambers and 6° diffuser were applied to find differences in the mixing process. Characteristics of the ejector, static pressure distributions and pressure fluctuations were measured to find how the different shape of the mixing chamber affect the efficiency of mixing processes. Pressure fluctuation increased rapidly while the ejection ratio was higher than 1.25 and the highest efficiency of the ejector was obtained when using configuration 4-4-6.
Optimization of Recast Layer Thickness and Surface Roughness in the Wire EDM Process of AISI H13 Tool Steel Using Taguchi and Fuzzy Logic
Authors: Rupajati Pathya , Soepangkat Bobby Oedy Pramoedyo , Pramujati Bambang , Agustin Helena C. Kis
Published: January 2014

In this study, the optimization of recast layer thickness and surface roughness (SR) simultaneously in a Wire-EDM process by using Taguchi method with fuzzy logic has been applied. The Wire-EDM process parameters (arc on time, on time, open voltage, off time and servo voltage) were optimized with considerations of multiple performance characteristics, i.e., recast layer thickness and SR. Based on the Taguchi method, an L18 mixed-orthogonal array table was chosen for the experiments. Fuzzy reasoning of the multiple performance characteristics has been developed based on fuzzy logic, which then converted into a fuzzy reasoning grade or FRG. As a result, the optimization of complicated multiple performance characteristics was transformed into the optimization of single response performance index. Experimental results have shown that machining performance characteristics of Wire-EDM process can be improved effectively through the combination of Taguchi method and fuzzy logic.
Design and Application of the Stretching Technology on the Welding Process of Stiffened Sheet Metal Structure
Authors: Sukanto Heru , Triyono Triyono , Muhayat Nurul
Published: January 2014

Stiffened sheet metal structure where sheet metal is reinforced by frame has been claimed as the most effective structure because it has low volume and weight. It is generally applied to large car body structure such as bus and train body. Frame and sheet are commonly joined by welding process. Due to the local heating of welding, distortion or deformation will occur in this structure. To mitigate this distortion, new method called stretching technology was proposed in this work. In this method, sheet was stretched to certain pre-strain, kept in this condition and then welded to frame. Special equipment powered by hidroulic system was designed to support this method. Low carbon steel SPAC specimens with dimension of 400mm, 1824mm and 3mm in width, length and thick respectively were prepared to evaluate the method. Hidroulic power was controlled to meet the sheet pre-strain variations of 0.00%, 0.05%, 0.10% and 0.15%. The distortion of the specimen was measured by dial indicator with mesh point of 50mm and shown in 2D contour chart. The study results revealed that the welding process on the sheet without pre-strain had the highest distortion of 8.34mm while that with pre-strain of 0.05% provided the lowest distortion of 3,3mm or 60% lower than without pre-strain specimen. The pre-strain of 0.10% and 0.15% produced the sheet distortion of 7.05mm and 7.9mm respectively. The excessive pre-strain was an ineffective method to mitigate the welding distortion because the reverse tension force of sheet would destroy the weld joint when the hydraulic force was released.
Visible Light Maskless Photolithography for Biomachining Application
Authors: Suwandi Dedi , Whulanza Yudan , Istiyanto Jos
Published: January 2014

Maskless photolithograpy is an alternative method of conventional UV photolithograpy for microfabrication since its advantages of time and cost saving. For this reason, a visible-light based maskless photolithograpy is proposed as a part of biomachining process. Modification of the method is done by replacing light source of UV light to visible light, utilizing commercial DLP projector and changing the material removal process that generally uses echant with biomachining process. The process was done by using the profile generated by computer then displayed through a commercial DLP projector shining speciment test. Focusing lens placed under the projector to draw the focal point and reduces the size of the profile. The best parameter was determined by setring exposure time, developing time, variation profiles, focusing, colors combination and optical aspect. Using a commercial projector maskless photolithography on a negative resist tone successfully performed. The best characteristic was obtained by placing the focusing lens 3X magnification within 3 cm below the projector and 14 cm above speciment test, color combination of black-light blue (R = 0, G = 176, B = 240), with the timing of prebake 1 minute, exposure 7 minutes, postbake 5 minutes, developing 5 minutes produces the smallest profile 166 μm with 13,7 μm deviation. Biomachining process with bacteria Acidithiobacillus ferrooxidans NBRC 14262 on copper was also successfully performed with the smallest profile of 180 μm with 26 μm deviation.
Improvement of Tungsten Inert Gas (TIG) Welding Penetration Using the Effect of Electromagnetic Field
Authors: Baskoro Ario Sunar , Tuparjono Tuparjono , Erwanto Erwanto , Frisman S. , Yogi Adrian , Winarto Winarto
Published: January 2014

Tungsten Inert Gas (TIG) welding is a process which an electric arc generated by the tungsten electrode to the workpiece and the welding area protected by a protective gas. Arc shape can be affected by electromagnetic force. In previous study, the use of some electromagnetic field around the arc has influenced the welding results. In this study, electromagnetic field generated from the solenoids was given to the welding arc. Welding process was conducted on Stainless Steel. The electromagnetic field made the arc becomes deflected. This deflection was controlled by the solenoid by activating it using a microcontroller. The results showed that the use of solenoid as a source of electromagnetic field has influenced the welding arc. Penetration produced by using a solenoid has deeper penetration than welding process without using solenoid. The increase of the welding power efficiency was 10.9% for arc current I = 80 A and 9.85% for arc current I = 90 A.
Response of Grip Force as Effect of Electrics Power Input at Gripper Actuator of NiTi SM495 Wire
Authors: Oerbandono Tjuk , Budiarto Hari
Published: January 2014

Gripper is mechanism that mounted on the end of the robot arm and used to hold an object and move it to a certain position. Generally, classical gripper is equipped with the driving motor (electric, pneumatic, fluid power) to move the gripper mechanism. In this research, the function of driving motor replaced with gripper motor actuators made of Shape Memory Alloys (SMA) of Nickel Titanium (NiTi) wire type SM495. Problem studied is response of grip force of gripper to varied electrics power input that given to the actuator of gripper made of NiTi SM495 wire. This is a real experimental research using parameters electrical power input which is obtained by varying the applied electric voltage 3, 6, 9, 12 Volt and constant electric current 5 A. Linear springs with various springs constants of 0.14 N/mm; 0.49 N/mm; 0.981 N/mm; 1.308 N /mm were used for measuring grip force of gripper. The obtained data then analyzed using statistics (analysis of variance). The results showed that the electrical power which given to the NiTi based actuator significantly influenced the grip force of gripper.
Keywords: actuators, electric power, grip force, gripper, Nickel Titanium,
Shape Memory Alloys, SM495 wire
Image Processing Implementation in Measurement of Cross-Flow Water Turbine Geometry
Authors: Wahjudi Arif , Batan I Made Londen , Pradnyana Bagus Mertha , Rusweki Windy
Published: January 2014

Recently, many studies have been done to look for renewable energy sources such as kinetic energy from marine or fluvial currents. In its utilization, water turbine plays an important role for taking energy from water current. One of the water turbine types is Cross Flow Water Turbine (CFWT). The performance of the CFWT depends on its geometry. Unfortunately, its geometry is very difficult to be measured using conventional measurement because it has complex geometry. Hence, a non-conventional measurement system based on image processing is proposed in this study to deal with the measurement difficulty of the CFWT geometry.
Effect of Ingredients on Flexural Strength of Friction Composite
Authors: Jamasri Jamasri , Malau Viktor , Ilman Mochammad Noer , Surojo Eko
Published: January 2014

In the present work, a friction composite material which will be used for material of train brake shoe was investigated to study the effect of ingredients on flexural strength. The Taguchi method is used to measure relative effect of ingredients on flexural strength of composite. Taguchi L8 orthogonal array which consists of 7 factors with 2 levels each is applied to perform experiment. Ingredients of friction composite were considered as factors or parameters and % volume for each factor was varied at 2 levels. Phenolic resin and barite (BaSO4) were not included as factor. Phenolic resin was always kept constant at 30 % volume and % volume of barite (BaSO4) was varied to compensate the changing of other ingredients amount. The results show that glass fiber and cast iron chip have significant effect on increasing of flexural strength of brake shoe composite. Conversely, NBR has significant effect on decreasing of flexural strength of brake shoe material. Cashew dust, Cu short wire, fly ash and graphite have insignificant effect on flexural strength. Cu short wire cant play a role as reinforcement fiber in brake shoe composite because there is weak bonding between Cu short wire and matrix.
Acoustic Emission Hit Generation Behavior of Basalt Fiber High Strength Mortar under Compression
Authors: Kencanawati Ni Nyoman , Shigeishi Mitsuhiro
Published: January 2014

Acoustic emission (AE) has been applied to study the fracture mechanics of concrete and other cementitious materials. In this paper, the AE hit generation behaviour is employed to investigate the fracture of high strength mortar containing basalt fiber under compression. A variety of amount and length of basalt fiber were used in mortar mix. Result shows that there is no significant effect observed on behavior of AE hit generation due to the differences amount and length of basalt fiber in mortar. All indicates the similar behaviour that can be described into three stages. At the second stage when maximum load starts to occur, AE hits are generated significantly indicating nucleation of many cracks. Materials failure in ductile manner since AE activities still can be recorded at long after post peak behaviour.
An Experimental Study on the Vertical Flow Past a Finite-Length Horizontal Cylinder at Low Reynolds Numbers
Authors: Stevanus Willy , Lin Yi Jiun Peter
Published: January 2014

The research studies the characteristics of the vertical flow past a finite-length horizontal cylinder at low Reynolds numbers (ReD) from 250 to 1080. The experiments were performed in a vertical closed-loop water tunnel. Flow fields were observed by the particle tracer approach for flow visualization and measured by the Particle Image Velocimetry (P.I.V.) approach for velocity fields. The characteristics of vortex formation in the wake of the finite-length cylinder change at different regions from the tip to the base of it. Near the tip, a pair of vortices in the wake was observed and the size of the vortex increased as the observed section was away from the tip. Around a distance of 3 diameters of the cylinder from its tip, the vortex street in the wake was observed. The characteristics of vortex formation also change with increasing Reynolds numbers. At X/D = -3, a pair of vortices was observed in the wake for ReD = 250, but as the ReD increases the vortex street was observed at the same section. The vortex shedding frequency is analyzed by Fast Fourier Transform (FFT). Experimental results show that the downwash flow affects the vortex shedding frequency even to 5 diameters of the cylinder from its tip. The interaction between the downwash flow and the Von Kármán vortex street in the wake of the cylinder is presented in this paper.
Application of Myrmecodia Pendans Extract as a Green Corrosion Inhibitor for Mild Steel in 3.5% NaCl Solution
Authors: Pradityana Atria , Sulistijono Sulistijono , Shahab Abdullah
Published: January 2014

The use of Myrmecodia Pendans (MP) extract as mild steel corrosion inhibitor in 3.5% NaCl media was investigated using weight loss and potentiodynamic polarization methods as well as characteristics analysis of the Fourier Transform Infra-Red (FTIR). Obtained data from weight loss and potentiodynamic polarization methods has shown the value of inhibition efficiency (% IE) is proportional toadded inhibitor concentration. Tafel constants data indicates that MP extract can act as cathodic and anodic inhibitors (type of mixed inhibitor). FTIR analysis also demonstrates the characteristics of MPextract. Occured inhibition mechanism was in the form of inhibitor adsorption process on metal surfacethat allegedly preceded by physical adsorption followed by chemical adsorption. Chemical adsorption is conceivable since metal surface scoping elevates as the increasing of inhibitor concentration.
Al2O3 – SiO2 Coating by Flame Spray for Thermal Barrier Coating Application
Authors: Widyastuti Widyastuti , Lilis Mariani , Ridwan S. , Putrawan M.A.
Published: January 2014

Nozzle is one crucial part of rocket. In this research, the nozzle was made by AISI 4340 coated by termal barrier coating (TBC). The TBC material is Al2O3SiO2 composite, with different variation: Al2O3 20% SiO2; 70% Al2O3 30% SiO2; and 60% Al2O3 40% SiO2. The aim of this research to observe the composittion which will produce optimum adhesive strength and the most widely formed mullite phase. Mullite is an expected phase formed from composite and it has thermal resistance during 1300°C. Coating process was conducted by flame spray with variation of plies. The effect ratio, plies, microstructure, phase, and adhesive strength of TBC were investigated using Scanning Electron Microscope (SEM), X-ray diffraction (XRD),) and adhesion testing. The results showed that the highest adhesive strength was 16 MPa for 20%SiO2 with 2 plies. The highest mullite forming was TBC. After heat treatment, it was found that the mullite phases were most widely formed at a composition of TBC 30% SiO2-70% Al2O3.
Sintering of Stainless Steel Nanopowders for Micro-Component Part Applications
Authors: Supriadi Sugeng , Baek Eung Ryul
Published: January 2014

Micro Metal Injection Molding utilizing 316 steel nanopowder with 100 nm in mean size was investigated to fabricate micro part. The nanopowder was used since its advantages to produce better surface roughness and detail structure in the micro part fabrication. During nanopowder preparation, thin oxide must be formed intentionally to avoid powder burnt before its exposed to the air during mixing with the wax binder system. Unfortunately, this oxide still exist after sintering and decrease the mechanical properties (ductility and densification) by the formation of secondary phase which detected as chrome oxide. In this paper, deep elaboration for oxide characteristics and the ways to reduce it by vary the sintering parameters and in Hydrogen atmosphere were described briefly. Here, we infer by reducing the heating rate, increasing the sintering temperature and utilizing the Hydrogen atmosphere can be effectively optimize the utilizing of nanopowder for micro part fabrication.
Effect of Air Conditioning Position on Thermal Comfort in the Floor Air Conditioning System
Authors: Sabtalistia Y.A. , Ekasiwi S.N.N. , Iskandriawan B.
Published: January 2014

Energy consumption for air conditioning systems (air conditioning system) increased along with the increasing need for fresh air and comfortable in the room especially apartments. FAC system (Floor Air Conditioning) is growing because it is more energy efficient than CAC (Ceiling Air Conditioning) system. However, the position of the AC supply is on the lower level at the FAC system causes draft discomfort becomes greater as air supply closer to the occupants so that thermal comfort can be reduced. Heat mixture of windows, exterior walls, kitchen, and occupants in the studio apartment affect thermal comfort in the room too.This study aims to determine the position of the AC supply which has the best thermal comfort of FAC system in the studio apartment. It can be done by analyzing ADPI (Air Diffusion Performance Index), the distribution of air temperature, wind speed, RH (Relative Humidity), and DR (Draft Risk) to change the position of the AC supply supported by CFD (Computational Fluid Dynamics) simulation.This result prove that AC position 2 (on wall near the kitchen) is more comfortable than AC position 1 (on the bathroom wall) because AC position 2 away from occupied areas, thereby reducing the occurrence of draught discomfort.
Laminar Flow Past a Circular Cylinder: Reduction of Drag and Fluctuating Lift Using Upstream and Downstream Rods
Authors: Noor Dedy Zulhidayat , Widiyono Eddy , Suhariyanto Suhariyanto , Rusdiyana Lisa , Sarsetiyanto Joko
Published: January 2014

Laminar flow past a circular cylinder has been studied numerically at low Reynolds number. The upstream and downstream rods have been used as passive control in order to reduce hydrodynamics forces acting on the cylinder. Both the upstream and downstream rods significantly contribute in reduction of drag and fluctuating lift compared to single cylinder without the rods. More detail, the upstream installation rod is more dominant in drag reduction than the downstream one. On the contrary, the downstream rod has suppressed the magnitude of the fluctuating lift almost twice that of the upstream configuration. Placing the two rods together as the upstream and downstream passive control in tandem arrangement has given more hydrodynamics forces reduction than the single rod configurations.Keywords:circular cylinder, passive control, tandem, drag, lift.
On the Possibility of the Estimation of the Depth of a Keyhole Formed during Laser Welding
Authors: Zowczak Włodzimierz
Published: January 2014

The simple model to estimate the depth of the keyhole during laser welding is presented. The model is based on the energy balance between the radiation absorbed by the kehole walls and the heat conducted in the horizontal direction. The calculations conducted for the solid and liquid phase give lower and upper estimate of the depth of the keyhole.
Evaluation of the State for the Material of the Live Steam Superheater Pipe Coils of V Degree
Authors: Trzewiczek Kamil , Szczotok Agnieszka , Gądek-Moszczak Aneta
Published: January 2014

The main aim of the undertaken research was to evaluate the state of the material of V degree live steam superheater pipe coils made of 10CrMo9-10 (10H2M) chromium-molybdenum steel as well as to determine their usability for further operation. The pipe coils came from a steam boiler working at a power plant. The scope of the research included: a literature analysis of the issue, an elaboration of the research plan, cutting and preparing the test samples, microstructural tests with the use of a light microscope, microstructural tests performed by means of a scanning electron microscope and conclusion drawing on the basis of the performed tests and the literature review. The work presents the steels of which the mentioned elements were made as well as analyzes their working conditions. It describes the most often observed causes of pipe coil damage and presents techniques of controlling the proper efficiency and usability of these elements for further operation.
Impact of the Parameters of Laser-Vibration Treatment on the Roughness of Aluminium Melts
Authors: Grabas Bogusław
Published: January 2014

This paper presents the preliminary, experimental results of laser-vibration treatment to increase the roughness of aluminium melts in compliance with EN AW-6060 (AlMgSi0.5). Using this method, metal objects are melted with a mobile laser beam while being vibrated. The effects of laser beam scanning velocity on the shapes of aluminium melts were studied at the set laser power and vibration frequency. The studied parameter was the mean roughness Ra. The value of Raparameter grew significantly. The studies were undertaken to employ this technology for the purpose of intensifying the exchange of heat in aluminium heating panels.
Effect of Temperature Changes on the Waveform of Fatigue Damage Accumulation
Authors: Mroziński Stanisław , Piotrowski Michał
Published: January 2014

In this paper there have been presented the results of low-cycle fatigue tests of steel P91 samples in the conditions of isothermal fixed amplitude loads as well as loads with a temperature change. Fixed amplitude isothermal loads were conducted on five levels of full strain and in two temperatures T1=20°C and T2=600°C. In the paper there has been found a significant influence of the sequence of temperature changes on the cyclic properties after the temperature change and on the fatigue life. The conducted experimental verification of the Palmgren-Miner hypothesis proved its influence on the temperature changes during the tests.
Fatigue Crack Growth in Titanium Alloy after Hardening and Ageing
Authors: Rozumek Dariusz , Hepner Maria , Marcisz Ewa
Published: January 2014

In this paper the results of experimental tests of the fatigue cracks propagation in Ti-6Al-4V titanium alloy subjected to cyclic bending are presented. The tests were performed on plane specimens with the stress concentrators in form of one-sided sharp notches. The tested specimens were made of the Ti-6Al-4V alloy subjected to oxygenating, and hardening and ageing. In the specimens after heat treatment, crack in the core has quite a different course than in the hardened oxygenated top layers.
The Issue of Low Cycle Fatigue Scope in the Description of Two-Parameter Fatigue Characteristics
Authors: Szala Grzegorz
Published: January 2014

This paper discusses the issue connected with determination of the low cycle fatigue scope for the two-parameter fatigue characteristics. Low cycle fatigue (LCF) and high cycle fatigue (HCF) evaluation criterion for constructional steel (C45, S355J0 and 41Cr4) has been discussed.
Analysis of P-M Damage Accumulation in Zirconium Dioxide; Testing through Gradually Increasing Load Method
Authors: Wirwicki Mateusz , Topoliński Tomasz
Published: January 2014

Zirconium dioxide has been known since the 90's. The Zirconium dioxide that has been used in the research was supplied by 3M ESPE under trade name Zirconium Lava. The trabecular rectangular shaped samples with dimensions of 1.5 mm x 1.5 mm x 12 mm has been put under three-point bending process in accordance to PN-EN 843-1:2006 standards. The tests were performed using the servohydraulic strength o R=0,1 at maximum compressive stress 700 and 710MPa, and a gradually increasing load for the two groups of samples. Aim of this study was to analyze the process of strengthening the quality of Zrconium dioxide by testing under variable loads including studies with gradually increasing load using linear fatigue damage accumulation hypothesis.
Damage Size Estimation of the Aircraft Structure with Use of Embedded Sensor Network Generating Elastic Waves
Authors: Dziendzikowski Michal , Dragan Krzysztof , Kurnyta Artur , Klysz Sylwester , Leski Andrzej
Published: January 2014

One of the approach to develop a system of continues, automated monitoring of the health of the structures is to use elastic waves excited in a given medium by piezoelectric transducers network. Elastic waves depending on their source and the geometry of the structure under consideration can propagate over significant distance. They are also sensitive to local structure discontinuities and deformations providing a tool to detect local damage of large aerospace structures. In the paper the issue of fatigue crack growth monitoring by means of elastic guided waves actuated by a sparse array of sensors will be presented. In particular we propose signal characteristics, robust enough to detect different kinds of damages: Barely Visible Impact Damages (BVIDs) in composite materials and fatigue cracks of metallic structures. The model description and the results of specimen tests verifying damage detection capabilities of the proposed signal characteristics are delivered in the paper. Some issues concerning the proposed damage indices and its application to damage detection and its monitoring are also discussed.
H2S Increases Survival during Sepsis: Protective Effect of CHOP Inhibition
Authors: Ferlito Marcella , Wang Qihong , Fulton William B. , Colombani Paul M. , Marchionni Luigi , Fox-Talbot Karen , Paolocci Nazareno , Steenbergen Charles
Published: January 2014

Sepsis is a major cause of mortality, and dysregulation of the immune response plays a central role in this syndrome. H2S, a recently discovered gaso-transmitter, is endogenously generated by many cell types, regulating a number of physiologic processes and pathophysiologic conditions. We report that H2S increased survival after experimental sepsis induced by cecal ligation and puncture (CLP) in mice. Exogenous H2S decreased the systemic inflammatory response, reduced apoptosis in the spleen, and accelerated bacterial eradication. We found that C/EBP homologous protein 10 (CHOP), a mediator of the endoplasmic reticulum stress response, was elevated in several organs after CLP, and its expression was inhibited by H2S treatment. Using CHOP-knockout (KO) mice, we demonstrated for the first time, to our knowledge, that genetic deletion of Chop increased survival after LPS injection or CLP. CHOP-KO mice displayed diminished splenic caspase-3 activation and apoptosis, decreased cytokine production, and augmented bacterial clearance. Furthermore, septic CHOP-KO mice treated with H2S showed no additive survival benefit compared with septic CHOP-KO mice. Finally, we showed that H2S inhibited CHOP expression in macrophages by a mechanism involving Nrf2 activation. In conclusion, our findings show a protective effect of H2S treatment afforded, at least partially, by inhibition of CHOP expression. The data reveal a major negative role for the transcription factor CHOP in overall survival during sepsis and suggest a new target for clinical intervention, as well potential strategies for treatment.