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Pneumatic mechanism widely used in industrial, automotive, aerospace, and etc. The principle of pneumatic like piston is move up and down due to the air pressure inside the piston. Mechanism of piston can be applied to the power plant that utilizes the ocean waves where as use of piston mechanism is very helpful in solving the problem of fossil fuel scarcity as a source of energy in power plants. In this study we will focus on the pneumatic system which utilizing ocean wave that moves longitudinally to encourage buoy that located on the piston shaft to up and down and then the pressing of air out of piston. Output of the piston will be forwarded to the generator (rotor and stator) to produce a voltage. In this paper is focused on the manufacture of pneumatic systems and processes to produce the rotation and voltage. Material of piston tube component made of aluminum and rubber, buoys made of plastic and generator such as of metal and copper coils. Output of the piston will be forwarded to the generator (rotor and stator) to produce a voltage. In this paper is focused on the manufacture of pneumatic systems and processes to obtained the rotation and voltage with aluminum for piston tube material, buoys made of plastic and magnet rotor and copper coils of stator include on the generator and get the results of ocean wave power plant using piston mechanism is 1400 rpm with a voltage of 36 volt.

The objective of this paper is measurement of the surface roughness of tensile specimens under different tensile speed. In the test, the tensile specimens were loaded by tensile testing machine. The roughness of the surfaces was measured by digital holographic interferometric system (DHI). From the results, it was confirmed that DHI could measure the roughness of the various types of the specimen surface. In this paper, as the tensile speed was faster, the roughness of specimen surface was smaller.

This paper presents an experimental methodology to determine a Friction Stir Welding (FSW) means of production based on the experimental study of the tool / material mechanical interactions generated during the plunging and welding stages. These two stages have been identified as being characteristic for the qualification of a FSW equipment. This paper presents the experimental results of the parametric study done on the plunging and welding phases. Ranges of forces and torques diagrams were established according to the processing parameters, in order to qualify a means of production and select the process parameters allowing the operation on the available FSW equipment.

Cracks in railway prestressed concrete sleepers are often caused by the infrequent but high magnitude impact forces. These impact forces are attributed to the wheel or rail abnormalities, e.g. wheel flat, corrugation, dipped joint, etc. The emphasis of this paper is placed on the corresponding fractures of railway prestressed concrete sleepers in track systems under the probabilistic impact loadings. The statistical data of impact loadings in Central Queensland have been obtained through the collaborative project under the research framework of the Australian Cooperative Research Centre for Railway Engineering and Technologies. It is found that for the heavy haul railway network, the track structures, especially the concrete sleepers, may experience the impact loading from 400kN up to 800kN. The corresponding probabilities of such load occurrences are ranging from one in twenty years to one in thousands of years. It is very important for the design and maintenance perspectives to investigate the impact behaviour of concrete sleepers under the impact loadings. This paper presents the impact fractures of railway prestressed concrete sleepers under the single impact loading associated with the probability of occurrence in the soft track environment. Visual interfacial cracks have been evaluated for the crack length and width along the sleepers in relation to the probability of load occurrence.

Buildings are responsible for more than 40% of the energy consumption and greenhouse gas emissions. Thus, increasing building energy efficiency is one the most cost-effective ways to reduce emissions. The use of thermal insulation materials could constitute the most effective way of reducing heat losses in buildings by minimising heat energy needs. These materials have a thermal conductivity factor lower than 0.065 (W/m.K) while other insulation materials such as aerated concrete can go up to 0.11. Current insulation materials are associated with negative impacts in terms of toxicity. Polystyrene, for example contains anti-oxidant additives and ignition retardants. In addition, its production involves the generation of benzene and chlorofluorocarbons. Polyurethane is obtained from isocyanates, which are widely known for their tragic association with the Bhopal disaster. Besides current insulation materials releases toxic fumes when subjected to fire. This paper presents experimental results on one-part geopolymers. It also includes global warming potential assessment and cost analysis. The results show that only the use of aluminium powder allows the production mixtures with a high compressive strength however its high cost means they are commercially useless when facing the competition of commercial cellular concrete. The results also show that one-part geopolymer mixtures based on 26% Ordinary Portland Cement (OPC)+58.3% Fly Ash (FA)+8% Calcined Stuff (CS) +7.7% Calcium Hydroxide (CH) and 3.5% hydrogen peroxide constitute a promising cost efficient (67 euro/m3), thermal insulation solution for floor heating systems with low global warming potential of 443 KgCO2eq/m3.

This paper shows a comparison between two different MOSFET structures: a conventional layout (CM) and Diamond (DM - enclosed layout transistor), as tolerance to the Single Event effect - SEE. Both CMOS 0.35μm technology devices types have the same geometric factor (W/L) and during irradiation were monitored continuously to detect and acquire the SEEs applying a new approach with a PXI test system. For this work was used heavy ion beams produced at the São Paulo 8 UD Pelletron accelerator.

Nowadays, demand for automated Gas metal arc welding (GMAW) is growing and consequently need for intelligent systems is increased to ensure the accuracy of the procedure. To date, welding pool geometry has been the most used factor in quality assessment of intelligent welding systems. But, it has recently been found that Mahalanobis Distance (MD) not only can be used for this purpose but also is more efficient. In the present paper, Artificial Neural Networks (ANN) has been used for prediction of MD parameter. However, advantages and disadvantages of other methods have been discussed. The Levenberg–Marquardt algorithm was found to be the most effective algorithm for GMAW process. It is known that the number of neurons plays an important role in optimal network design. In this work, using trial and error method, it has been found that 30 is the optimal number of neurons. The model has been investigated with different number of layers in Multilayer Perceptron (MLP) architecture and has been shown that for the aim of this work the optimal result is obtained when using MLP with one layer. Robustness of the system has been evaluated by adding noise into the input data and studying the effect of the noise in prediction capability of the network. The experiments for this study were conducted in an automated GMAW setup that was integrated with data acquisition system and prepared in a laboratory for welding of steel plate with 12 mm in thickness. The accuracy of the network was evaluated by Root Mean Squared (RMS) error between the measured and the estimated values. The low error value (about 0.008) reflects the good accuracy of the model. Also the comparison of the predicted results by ANN and the test data set showed very good agreement that reveals the predictive power of the model. Therefore, the ANN model offered in here for GMA welding process can be used effectively for prediction goals.

Lasers have the potential for the micromachining of germanium (Ge). However, the thermal damages associated with the laser machining process need to be properly controlled. To minimize the thermal damages, a hybrid laser-waterjet ablation technology has recently been developed for micromachining. This paper presents an experimental study to assess the machining performances in microgrooving of Ge by using a nanosecond laser and the hybrid laser-waterjet technology. The effects of laser pulse energy, pulse overlap and focal plane position on the groove geometry and heat affected zone (HAZ) size are analyzed and discussed. It is shown that the hybrid laser-waterjet technology can give rise to narrow and deep microgrooves with minimum HAZ.

This paper introduces a new approach for the identification of linear state-space models of dynamical systems of arbitrary complexity. The identification procedure is described and applied for modeling aeroelastic response of helicopter main rotors. With the aim of developing a tool that might be conveniently applied for real-time simulations of helicopter flight dynamics, the state-space model considered is a reduced-order description of loads transmitted to the airframe due to hub motion and blade pitch controls. In order to validate the proposed approach, loads from the state-space, reduced-order model are compared with those predicted by the complete full-state, nonlinear rotor model for prescribed helicopter maneuvers.

Multi-criteria optimization problems are known to give rise to a set of Pareto optimal solutions where one solution cannot be regarded as being superior to another. It is often stated that the selection of a particular solution from this set should be based on additional criteria. In this paper a methodology has been proposed that allows a robust design to be selected from the Pareto optimal set. This methodology has been used to determine a robust geometry for a welded joint. It has been shown that the robust geometry is dependent on the variability of the geometric parameters.

Strain is routinely used in state-of-the-art semiconductor devices in order to improve their electrical performance. Here we present experimental strain measurements obtained by different transmission electron microscopy (TEM) based techniques. Dark field electron holography, nanobeam electron diffraction (NBED) and high angle annular dark field scanning electron microscopy (HAADF STEM) are demonstrated. In this paper we demonstrate the spatial resolution and sensitivity of these different techniques on a simple calibration specimen where the accuracry of the measurement can easily be assessed. Introduction. Although the effects of introducing strain in semiconductor devices is well known from an electrical point of view, little is known about the distribution of strain. Indeed, it is only in the last few years that methods that can measure the strain with the required level of spatial resolution have been developed. Dark field electron holography (1), NBED (2) and HAADF STEM (3) are different TEM based techniques that have been developed in order to solve this problem. A calibration specimen was designed so that the different strain mapping techniques could be tested and compared to accurate simulations that would account for the relaxation of the thin TEM specimen. The calibration specimen that was examined was grown by reduced pressure chemical vapour deposition and comprised from top to bottom, a 150-nm-thick capping layer, then four 10- nm-thick SiGe layers with Ge concentrations of 45%, 38%, 31% and 20%, each separated by 30nm of silicon on a silicon substrate. As the growth is epitaxial, the lattice spacing in the in-plane (x- direction) does not change. However, in the growth (z-direction) the lattice parameter is expanded relative to the unstrained substrate due to the presence of Ge and it is this relative expansion which is measured. The dark holography experiments were performed using a probe corrected FEI Titan operated at 200 kV, the precession NBED (PED) and the HAADF STEM experiments were performed using a double corrected FEI Titan operated at 200 kV. All of the data was processed using software written at CEA.

Dye-sensitized solar cell (DSSC) is part of the thin film family that consists of a TiO2 electrode coating which acts as a photo electrode, sensitizer from dye molecules soaked in the TiO2 film, electrolyte layer and a counter electrode. This paper focuses on the usage of a sensitizer from the rose flower and will review some of the research conducted on dye sensitizers from other researcher. Rose flower also known as woody perennial of the genus Rosa, within the family Rosaceae is extracted and were used as sensitizer to fabricate dye sensitized solar cell (DSSC). The photoelectrochemical performance of Rose sensitized solar cell shows parameter of open circuit voltage, VOC,short circuit current, (ISC), fill factor (FF), solar cell efficiency (η), and peak absorbance rate as much as 0.13 V, 57.58 µA, 0.58, 0.85% and 3.5 at 550nm respectively. The photoelectrochemical performance of DSSC and the usage of natural sensitizer from Rose flower dye demonstrate good potential to be applied as a sensitizer yet detail investigations are essential in terms of its applicability for long term application.

During the revision of the individual parts of a hydroelectric power plant the cracks in the pins of quick operating and revision flap valves of Francis turbine were found. Our department has been approached with a request to investigate the causes of these cracks. This paper deals with the complex analysis of influential factors, especially the measurements of residual stresses by hole-drilling method, in order to reveal the factors causing the cracks in the pins.

Retracted paper: The conventional material for the optical fiber communication laser diode is based on InGaAsP, which might be substituted by a potential candidate, InGaAlN. The new active region material, InN, is introduced regarding to its crystal growth and characterization, including the structural, optical and electrical properties. This material is promising for providing good performance of temperature stability of the wavelength. In addition, it is environmentally friendly.

A wireless ad hoc network is a self-configuring infrastructurelessh network of mobile devices connected by wireless. In order to support the basal networking functions like routing and packet forwarding, the nodes in wireless ad hoc network should be cooperate with each other due to the limited range of wireless transmission. However, nodes are unwilling to relay packets for others considering the poor energy and bandwidth especially in the open community environment. Some approaches to stimulate nodes cooperation have been introduced recently. In this paper, we provide a novel method based on cross-layer design to solve the cooperation issues both in Mac and network layer. The method with the help of reputation mechanism and utility function based on game theoretical approach can promote nodes to cooperate and make the whole network to reach Nash equilibrium.

Continuous wave (CW) radar and global positioning system (GPS) is the main equipment of trajectory measurement in range. Based on range test background, propose a method to fuse GPS pseudo-range and CW radar range to provide complete trajectory positioning parameters, effectively reduce the impact of the systematic error of the measuring element to improve positioning precision of aircraft orbit solving. Through research on the measurement principle and the practice calculated data is given in this paper. Finally, several famous practical examples and simulation results are presented to illustrate our method efficiently.

Web Service architecture gradually matures in the related applications of campus network, but campus network anomaly mining technology still needs further development in its confidentiality, integrity, and non-repudiation problems. In SOA, campus network anomaly mining technology still needs to strengthen safety and reliability. Based on suffix tree technology, this paper proposed the application of campus network information security technology based on network anomaly mining technology, analyzed the campus network security features in detail, and designed an anomaly mining algorithm on suffix tree campus network security. Computer simulation results show that the proposed method can rapidly mine the abnormalities of the network and ensure the security of campus network. KeywordsWeb log; Campus network; information security; data mining algorithm

This paper studied GPS location information of the collection, processing, GPRS data transmission network, intelligent building security system features. Based on this techniques, we designed an embedded GPS/GPRS intelligent building security system, which is composed of ARM9 microprocessor S3C2410, GPS/GPRS module and some peripheral devices. The system is running under Linux OS. The characteristics of the system are flexible, powerful, and high practicality. Keywords-Embedded system; intelligence building; GPS; GPRS

This paper analysis the causes dynamically loaded screws failure, using the structural analysis of mechanical properties and numerical simulation. The comparison with the new unbroken screws, which were not in use, has been done to determine the condition of the broken (dynamically loaded) ones. Analysis was performed, according to the following test methods and activities: non-destructive testing, visual inspection, radiographic testing, chemical analysis of screws sample materials, mechanical properties of screws' materials. Structure analysis of screws materials: Testing macrostructure (light optical microscope, SEM-EDS) examination of the microstructure (light optical microscope, SEM-EDS), fractographic examination. Numerical simulation of the stress state of the dynamically loaded screws was done in CATIA software package, and it was identical to the bolt loads, during service exploitation. The results between numerical simulation and structural analysis were quite coinciding - the difference is about 8-10%, which is pretty good for these types of experiments. Such an overlap, says that the stress value at the very screws is reliable and give us a true picture of loadings. Structural mechanical tests have shown a very pronounced effect of dynamic loads, that large shear stress shows also as a good agreement, where between the stresses, obtained by numerical simulation and structural mechanical testing. Analysing the results, obtained by numerical simulation and structural mechanical testing were performed with the redistribution of critical stresses, and proposal for the structure optimization. The comparative analysis methods have been provided the precise prediction of fracture appearance and made possible to define the preventive measures.

In this paper, a novel MEMS based LLC converter is proposed for on chip power supplies. The design is optimized based on commercially available Metal MUMPs process for fabrication. The resonant frequency is optimized at 20MHz and MEMS based variable capacitor is fabricated on the chip to tune the peak resonance frequency of circuit which varies due to the load variations. The Design is simulated in FEM based numerical software COMSOL and Intellisuite. According to analysis the magnetizing inductance of 42nH and leakage inductance of 40nH has been achieved from 16 mm2 rectangular coil transformer. The total capacitance of 1500pF has been achieved from parallel plate capacitors and variation of 3pF has been achieved from variable capacitor.

In consideration of low power density of electric excitation claw-pole alternator (EECA) and some difficulties in magnetic field regulation of permanent magnet claw-pole alternator (PMCA), a novel hybrid excitation brushless claw-pole alternator (HEBCA) is proposed in this paper. Its structure and field control principle are described. Three dimensional finite element analysis is used to obtain the no-load magnetic field distributions and field control capability under different field currents. The result shows that the flux of the prototype machine can be adjusted over a wide range with a relatively low field current

This paper presents an optimum selection of a co-generation system for heat and power generation at University of Technology Sydney, based on technological, environmental, social and economical factors. Five potential cogeneration concepts were developed based on Internal combustion (IC) engines, External combustion engines including Stirling engine, Organic Rankine cycle (ORC), Kalina cycle, and Fuel-cells, and compared. Organic Rankine Module (ORC) is finally selected. The selected cogeneration offers shorter payback period, lower IRRand net-energy savings, lower Co2 emissions, and higher electric-power generation capacity. © (2012) Trans Tech Publications.

[EN] This part analyzed GFRP rebar's research situation, summarized its behaviuor as internal reinforcement for concrete structures. The research has been developed over recent years, however the rules and standard codes for design RC concrete structures with these rebars not consider that the internal reinforcement can work in compression. This paper presents the development of the research to get a new kind GFRP rebar for work as internal reinforcement of concrete structures, with an innovative design for work both in tension and compression, and their mechanical properties: strength, bond,.... © (2012) Trans Tech Publications.

This paper reports the structural behavior of precast lightweight foamed concrete sandwich panel, PLFP, subjected to eccentric loading. An experiment was conducted to investigate the structural performance of PLFP under this load. Two PLFP panels, PE-1 and PE-2 were cast with 2000 mm in heights, 750 mm in width and 100 mm in thickness. The thickness of the wall is actually a combination of three layers. Skin layers were cast from lightweight foamed concrete while the core layer is made of polystyrene. The skin layers were connected to each other by 9 mm steel shear truss connector which were embedded through the layers. Panel PE-1 was strengthened with single diagonal shear truss connectors made of 6 mm steel rebar while panel PE-2 was strengthened with symmetrical diagonal shear truss connectors of similar steel diameter. Both panels were tested under eccentric load till failure. The results showed that panel with symmetrical double truss connectors, PE-2, is able to sustain higher load compared to panel with single shear truss connector. The load-deflection profiles indicate that both panels achieved certain degree of composite action especially during the later stage of loading where the wythes tend to move in the same direction until they reached failure. The load-strain curves for both panels highlight the inconsistent distribution of surface strain along the height of panels. The overall trend of the strain curves show that they are under compression.

A multiscale constitutive framework for Ni-base superalloys has been developed, in which an efficient unit cell is adopted to describe the γ/γ’ microstructure morphology. The framework enables the prediction of the deformation and the creep and fatigue damage accumulation in CMSX-4 for a range of temperatures and stress levels. Moreover, the material microstructural degradation due to rafting and isotropic coarsening can be simulated, and the effects of this degradation on the alloy mechanical response can be quantified. The present paper focuses on the application of the model to real gas turbine components. A high pressure turbine blade finite element model is used to demonstrate the computational efficiency of the multiscale framework. Moreover, the location of critical regions and the life time are shown to differ from the results obtained from classical models that neglect the microstructure evolution.

Built-up sections are used to resist load induced in a structure when a single section is not sufficient to carry the design load for example roof trusses. In current North American Specification, the provision has been substantially taken from research in hot-rolled built-up members connected with bolts or welds [1]. The aim of this paper is to investigate on built-up back-to-back channels stub columns experimentally and theoretically using Effective Width Method and Direct Strength Method. Compression test was performed on 5 lipped channel and 5 back-to-back channels stub columns fabricated from cold-formed steel sheets of 1.2mm thicknesses. The test results indicated that local buckling is the dominant failure modes of stub columns. Therefore, Effective Width Method predicts the capacity of stub columns compared to Direct Strength Method. When compared to the average test results, results based on EWM are 5% higher while results based on DSM are 12% higher for stub column.

In general, cracks in structural members indicate a level of serviceability of the engineering structures. Usually a hairline crack can be detected by visual inspection, crack gauge, fibre optical sensor, or laser sensor. Recently, an attempt to develop a non-destructive tool for health monitoring of prestressed concrete sleepers in railway tracks using the vibration responses has been established at the University of Wollongong, Australia. However, the fundamental understanding of the dynamic effect due to the cracks in sleepers is insufficient. This paper investigates the dynamic effect of the cracks on the vibration signatures of the railway prestressed concrete sleepers. The modal analysis has been used to evaluate the modal changes in vibration characteristics of the prestressed concrete sleepers in the frequency band between 0 and 1,600 Hz. The sample cracks have been initiated by the impulsive forces attributed to the high capacity drop impact testing machine. Comparison of the modal parameters of the intact and cracked sleepers has been highlighted in terms of natural frequencies and modal damping. This understanding will lead to further development of the economical technology to evaluate the structural integrity of railway track and its components.