bluuebunny/crossref_metadata_2025 huggingface dataset:
Research on Light Intensity Modulation within KDP Crystal Based on Different Width of Gaussian Repaired Contour of Surface Defects
Authors: Xiao Yong , Chen Ming Jun , Zhang Wen Ming , Li Ming Quan , Cheng Jian
Published: August 2014

Surface micro-defects of large diameter KDP crystal have great influence on its laser damage threshold. The method of micro-mechanical repairing can inhibit growth of the laser damage obviously. The paper adopts Fourier modal method to periodically process Gaussian repaired contour and established the light intensity modulation model of the Gaussian contour inside the crystal. Based on the model, the paper researches the influences on the light intensity inside the crystal made by Gaussian repaired contour with different width. Calculation results show that when the curve depth is fixed, the maximum relative light intensity decreases gradually as the curve width increases. Through experiments of micro-mechanical repairing and laser irradiation, we find that the laser damage threshold of Gaussian repaired contour with 20μm depth and 400μm width is 3ω, 5J/cm2. Meanwhile, experimental results verify the theoretical analysis. Keyword: KDP crystal, Gaussian repaired contour, internal intensity modulation, Fourier modal method, surface defect
The Development of an Displacement Sensor Embedded Voice Coil Motor Based Fast-Tool-Servo for the Machining of Micro-Structure
Authors: Yang Zhi Jun , Bai You Dun , Wang Su Juan , Chen Xin Du , Liu Qiang , Li Ke Tian , Wang Han , Chen Xin
Published: August 2014

The Fast Tool Servo (FTS) is widely used for the machining of micro-structures, especially for optical micro lens array. The working principle of FTS is that a voice coil motor or a piezoelectric (PZT) actuator is used as the driving elements, and the flexure hinges are developed as the guide mechanisms. In addition, an optical encoder is applied to measure the displacement. However, the existing design of FTS is too complicated and expensive. One reason is that the stroke of the FTS for the fabrication of optical micro lens array is only a few hundred micrometers, while its precision reaches to nanometric range, thus the optical encoder in not applicable. On the other hand, there exists sluggish and creep for piezoelectric materials, which makes the control of displacement difficult. This paper develops a displacement sensor embedded voice coil motor. In the design, the driving element is ampere force of the voice coil motor which is a linear ratio to the input current. Both the two covers are thin plates which serve as compliant mechanism by supporting the deformation at the Radial direction and provide linear stiffness in the axial direction. Therefore, the output displacement is proportional to the ampere force. The existence of external force affects the actual displacement, an embedded capacitor serves as displacement sensor will detects the real displacement, and the external force can be estimated by the current and measured displacement, which makes the motion control easy. At the same time, a multiphysics model of the developed FTS is built in this study by using finite element method and the displacement control under different cutting force is studied. The experimental results show that the developed FTS is efficient for achieving short stroke with high precision.
Automatic Optical Measurement of High Density Fiber Connector
Authors: Chang Chun Li , Chen Chun Jen , Wu Wen Hong
Published: August 2014

This paper will develop an automatic and fast optical measurement system for high density optical fiber connector measurement, which base on the optical project method. It will meet the lot of optical fiber connector measurement need. This system includes a high intensity and high collimated LED source, a high accuracy and high stiffness linear stage, 2 multi-degree-of-freedom adjustment mechanisms and a high resolution coaxial telecentric imaging system and image processing software. The system of measurement results and commercial measuring instruments comparing the results of its error is less than 0.6μm. To measure a V groove needs 750ms, this result may satisfy the requirements of automatic inspection.
Comparison Measurement between Fizeau Interferometer and Scanning Deflectomtric Profiler
Authors: Kondo Yohan , Bitou Youichi
Published: August 2014

There is a strong demand to measure an absolute surface profile with a few nanometer uncertainty. The National Metrology Institute of Japan (NMIJ) measure the absolute surface profile using two instruments based on difference methods: the Fizeau type flatness interferometer and the scanning deflectometric profiler. In the Fizeau type flatness interferometer, the measurand is a gap distance between a reference flat and a specimen. To obtain an absolute profile of the specimen, the reference flat was evaluated by a three flat test and a FEM analysis. The three flat test is one of the methods to measure absolute profile of a reference flat; however, the reference flat deforms under the force of gravity, and its absolute value cannot be detected by the three flat test. The deformation value of the reference flat was calculated by the FEM analysis. In the scanning deflectometric profiler, a local slope angle of a specimen is measured using an autocollimator and the surface profile is obtained by integrating with the local slope angles. To obtain an absolute profile of the specimen, the autocollimator which is key elements for the scanning deflectometric profiler was evaluated by using the self-calibration type rotary table. In this paper, we performed the comparison measurement between the Fizeau type flatness interferometer and the scanning deflectometric profile and verified the accuracy of the two instruments based on the different methods.
Measurement of Step Height Using White Light Spectral Interferometry
Authors: Guo Tong , Ni Lian Feng , Ma Long , Chen Jin Ping , Fu Xing , Hu Xiao Tang
Published: August 2014

The development of micro-nanomanufacturing technology leads to higher requirement for measurement technology, which gives birth to the ultra-precision measurement technology. As a kind of low coherence interferometry technology, spectral interferometry has been proposed. In this paper, the theory and system of white light spectral interferometry were described in detail, and the measurement principle of micro-structure was analyzed. The spectral interference signal was recorded and the phase information was retrieved from it by using five-step phase shifting algorithm, which includes the phase change on reflection from the stucture. So the optical path difference (OPD) can be obtained, which represents the height information. Three methods including slope method, single wavelength method and least square method were discussed based on the theory deduction and the experimental analysis. A step height standard was measured and the results show that this method has a good accuracy.
Study on Chemical Interaction Analysis of Reactive Fullerenol Molecules in Cu-CMP Using High-Sensitive Raman Spectroscopy
Authors: Murai Ryota , Takaya Yasuhiro , Hayashi Terutake , Michihata Masaki
Published: August 2014

Surface with nanometer accuracy is required to manufacturing process of integrated circuit (IC) devices. One of the most promising techniques for surface planarization is chemical mechanical polishing (CMP). CMP is a high efficiency process, both due to the varied chemical and physical properties of the surface materials. Conventional CMP uses the slurry, which is composed of abrasive particles suspended in a chemical solution. The abrasive particle is effective for surface planarization by a chemical mechanism with little mechanical abrasion. So chemical reactivity appears to be an essential factor of CMP process. In our conventional study, fullerenols have been proposed as suitable abrasives for copper CMP. The chemical reactivity of fullerenol is suggested by the fact that high removal rate (150 nm/min) and surface flatness (0.6 nm RMS) have been confirmed using fullerenol slurry. In this study, we analyzed the chemical reactivity between fullerenol molecule and copper surface, which is important to understand the material removal mechanism. Using the intrinsic Raman spectroscopic signal of interaction between fullerenol and copper with surface plasmon resonance (SPR), the chemical reactivity over a period of the reaction process was analyzed. Raman spectroscopy is commonly used in chemical analysis, since vibrational information is specific to the chemical bonds and symmetry of molecules. Therefore, it provides a fingerprint by which the molecule can be identified. However, spontaneous Raman spectroscopic signal is typically very weak, and as a result the main difficulty of Raman spectroscopy is separating the weak inelastically scattered light from the intense Rayleigh scattered laser light. Then Raman spectroscopic signal in this study is further enhanced by the SPR, also known as surface enhanced Raman scattering (SERS). The increase in intensity of the Raman spectroscopic signal for adsorbates on copper surface occurs because of an enhancement in the electric field provided by the surface. This technique enables high-sensitive analysis in the near-surface region. The signature of copper-oxygen bond was measured by Raman spectroscopy for fullerenol/copper system by in-process SERS analysis. It is thought to be caused by the hydroxyls of fullerenol molecule adsorbed on the copper surface. This result suggests that fullerenol molecules absorbing onto the copper surface affect the high efficient material removal.
The Assembly and Measurement of Corrector Lens of a Cassegrain Telescope
Authors: Huang Po Han , Hsu Ming Ying , Huang Ting Ming , Guo Ren Jyue , Lin Jhih Yang , Chen Zong Yao
Published: August 2014

Corrector lens assembly is used to expand the field of view of a Cassegrain Telescope. There are usually three to five lenses in it. For the assembly of such a kind of high precision optics, decenter and tilt of each optical component and air space between components are key issues to be qualified. In the present study, four lenses were designed. Individual control of centering of the component and air space were achieved by assembling the component into a precision machined subcell. The lens positions were defined by precision spacers according to the designed values. To compensate various thermal expansions of glass and metal, elastomer material was used. Considering the deviation of manufacturing from design data, manufactured data were put into optical software for re-optimization, and air spaces between lenses were obtained. This gives excellent accuracy at low cost. Base on present lens mounting design and lens manufacturing quality, centering error was eliminated by lateral adjustment, which leaded to a good alignment. In this paper, the method for aligning the optics with the barrel assembly is presented and centering error measured by a double autocollimator is listed. In addition, test results of thermal cycling and vibration tests on the corrector lens assembly are discussed.
Identification on Nonlinear Friction Model and Tracking Control for a Ball-Screw Actuated Stage Using Modified Charge System Search
Authors: Lin Chih Jer , Yu Shen Kai , Ho Bo Yen , Chen Chin Sheng
Published: August 2014

High precise positioning and high-speed performance are demanded for servo mechanical systems in recent industry. However, the nonlinear friction is a main factor to make the positioning mechanism imprecision. To improve the positioning the positioning precision of stages driven by ball-screws, there are two types of compensations including model and non-model based methods. In this study, the LuGre friction Model is applied to model the nonlinear friction behavior for a ball-screw driven stage. A Modified Charge Search System (MCSS) was proposed to identify the system’s parameter. After the system’s parameters are obtained, a feed-forward control integrated with a disturbance observer is proposed to eliminate the external disturbance and improve its tracking performance.
Molecular Dynamics Simulation of Pressure Generated inside Melting Area in EDM
Authors: Yang Xiao Dong , Han Xiao , Kunieda Masanori
Published: August 2014

Electrical discharge phenomena in EDM occur in a very short time period and in a very narrow space, thus making both observation and theoretical analysis extremely difficult. For this reason, the material removal mechanism in EDM has yet to be understood clearly. EDM is a thermal process. Thermal energy is generated by a pulse discharge between the workpiece and the tool electrode. It results in melting and evaporating followed by removal of both the workpiece and tool electrode, forming a discharge crater on both surfaces. In this paper, the hydrostatic pressure distribution in melting area was simulated by Molecular Dynamics (MD) methods. The analysis shows that after discharge is ignited, extremely high pressure is generated inside the melting area. The pressure distribution along the central axis of the melting area at different times indicates that during the discharge duration, the hydrostatic pressure quickly increases to a peak value along the depth direction of melting area and then reduced to 0 GPa in the unaffected area. It was also found that with the passage of time, the depth of the point where the pressure peaks increases with the formation of the discharge crater, accompanied by the decrease in the peak pressure. In addition, the ejected material atoms at different times during the removal process were also analyzed. It was found that the material ablation occurs mostly during the discharge duration.
High Resolution SelfA Rotary Table by the Interpolation Signal Calibration
Authors: Watanabe Tsukasa , Samit Watcharin , Vatcharanukul Ketsaya , Tonmueanwai Anusorn , Drijarkara Agustinus Praba
Published: August 2014

Self-A (Self-calibratable Angle device) rotary encoder can detect some kinds of angle error, not only its encoder scale error, but also the encoder attachment error (e.g. eccentricity error). When rotary table with built-in Self-A encoder rotates only one revolution, inner Self-A rotary encoder can calibrate the own angle error with a high accuracy. However, in the case of the Self-A using the encoder of 36,000 graduation scales, since the angular interval of the calibrated main scales corresponds to 36", it is insufficient for high resolution angular indexing control with high accuracy. Generally, the angle error of electric interpolation signal is estimated to be 1 % of main scale resolution that corresponds to about 0.36" for 36,000 scales encoder. Accordingly, even if Self-A had the ability which can calibrate in the accuracy 0.1", when it was controlling the rotary table using an electric interpolation signal, its total accuracy worsened to about 0.36". For improvement in precise angular-position control, we developed Self-A rotary table which can calibrate the angle signal at high resolution including electric interpolation signals. In this paper, we introduce the performance of the new high resolution Self-A encoder table. It keeps high accuracy and good repeatability in the 360° whole range as well as in the short range of ±1,000".
Performance Stability of Recycle Amine-Free Water-Soluble Coolant in Long Term Operation
Authors: Yamaguchi Kenji , Kondo Yasuo , Sakamoto Satoshi , Yamaguchi Mitsugu , Nakazawa Ryoichi
Published: August 2014

Recently, the concern for the environment has been increasing rapidly. In machining processes, the treatment of water-soluble coolants waste has caused environmental problems. Water-soluble coolants contain surfactants, preservatives, and corrosion inhibitors for maintaining the stability and performance of the coolants. To reduce the management cost and environmental effect of water-soluble coolants, the authors have been studying a recycling system for water-soluble coolants. In the recycling system, oil-free recycle water is isolated from the coolant waste and reused as a diluent of the new coolant. The authors have been developing different types of water recovery methods for the recycling system, and the recovered water from the coolant waste has potential as a diluent for a new coolant. In this report, we focused on the amine (alkanolamine) -free water-soluble coolant. Some amine-free water-soluble coolants have been developed and are commercially available. A reduction in the environmental effect in the waste treatment of coolants is expected with amine-free coolants. We have demonstrated that the amine-free water-soluble coolant has equal or better cooling and lubricating performance compared with the conventional amine-containing coolant. In addition, the amine-free coolant shows good recyclability for the recycling system. The processing time of the recycling treatment of the amine-free coolant has been decreased by half with our recycling process compared with the conventional amine-containing coolant. In this report, we examined the stability, cooling performance and lubricating performance of the recycle amine-free water-soluble coolant in long term operation. The recycle amine-free water-soluble coolant is operated in a 3-axis machining center for several months. We observed concentration, pH, corrosion inhibition performance, cooling performance, and lubricating performance of the coolant. The results from these experiments show the amine-free water-soluble coolant has the advantage to use in the recycling system for water-soluble coolant.
A Proposal of Process Strategy for Micro-Cutting Edge Fabrication: Effects of Shape Formation after Laser Hardening
Authors: Ogawa Keiji , Tanabe Hirotaka , Nakagawa Heisaburo
Published: August 2014

This paper proposes a novel process strategy for micro-cutting edge fabrication. Micro-cutting edges need a hardening process for the ridgeline parts that requires abrasive resistance, as well as edge sharpness and shape accuracy, based on their applications. Micro-cutting edge shapes also vary greatly in ridgeline profile and section. The proposed method is shape fabrication after laser hardening, which easily addresses these issues. In the present paper, effects of the proposed method are discussed and the results of a demonstration test are introduced.
Improvement of Accuracy in Micro-EDM of Tungsten Carbide Using Deionized Water
Authors: Nguyen Minh Dang , Neo Qian Yu , Rahman Mustafizur , Wong Yoke San
Published: August 2014

Tungsten carbide is widely used as molds and dies material due to its superior strength, hardness and wear resistance. However, these characteristics also make it very difficult to be machined. Because the material is removed by spark erosion, micro-EDM has been found to be an effective machining process to machine difficult-to-cut materials such as tungsten carbide. Notwithstanding that micro-EDM using deionized water yields many advantages compared to hydrocarbon oil such as higher removal rate, lower tool wear and thinner recast layer, it has not been widely used due to the poor dimensional accuracy of machined part. This is the result of stray material dissolution caused by the slight conductivity of deionized water. This unanticipated material removal is especially severe for tungsten carbide which is highly susceptible to corrosion. This paper presents an attempt to improve the accuracy of micro-EDM using deionized water by using short voltage pulses. A short pulses generator has been in-house developed for this purpose. The effects of pulse parameters on the stray material dissolution are investigated. It is observed that the stray material dissolution is localized when short voltage pulses are used. As a result, dimensional accuracy of machined parts is significantly enhanced.
Integrated Control System Based on MCU for the Temperature and Sampling of Helical Microfluidic PCR Detection System
Authors: Yang Yang , Chen Tao , Liu Shi Bing , Wu Jian
Published: August 2014

In this paper, based on the study of microbiological hazards real-time automatic alarm system for space applications and the “function integrated and structure miniature” of the microfluidic real-time PCR detection system, we have developed an integrated control system based on the MCU micro-processing chip for the control of constant temperature and sampling flow velocity of microfluidic PCR system. We have used the flexible polyimide film instead of traditional elements such as copper to facilitate the flow structure, which is characterized by small size, light weight and excellent heat transfer efficiency, applicable to the space environment. For the PID parameter tuning, by simulating the Z-N method of engineering turning based on the MATLAB/Simulink, a simple and efficient method for PID parameters turning is proposed in this paper. The practical application shows that the system is simple, strong applicability, high control accuracy, process visualization, fully automation control and adapt to the requirements of the space environment. It satisfies the development requirement of making the structural miniature and the function integrated. It can achieve the requirements of space applications by correcting and calculating the detection system in the conditions of weightlessness.
Design of Wrist Rehabilitation Device for Hemiplegic Patients
Authors: Park Tae Sang , Shin Dong Hwan , Jeong Choong Pyo , Choi Jung Hyun , Moon Jeon Il , Yang Seung Han
Published: August 2014

There have been some devices for rehabilitations of upper limb such as electronic device and mechanical device which is well-known as the passive one. These devices make the motion of upper limbs and stimulate the wrist, elbow, shoulder joints with muscles. This motion does by using the patient’s normal hand (left or right hand) and rotating the wounded hand’s wrist to be recovered by the clockwise or counterclockwise with some angles. Electronic devices for upper limb rehabilitation have the advantage that the electronic ones can supply various rehabilitation exercises to the patients. However these electronic devices include relatively expensive components such as various kinds of sensors, controllers, and display device. Therefore, the prices of implementation are too expensive. On the other hand, in conventional passive upper limb rehabilitation, the patients grasp the both handles without any mechanical links. It does not supply proper rehabilitation motion because the normal hand does not supply the rehabilitation motion to hand to be recovered. So to speak, this is not proper to patients with the one hands trouble such as hemiplegic patients, by himself without the aids of any other persons. In this paper, we describe the mechanical device for rehabilitations of wrist and the proposed handles to be attached in this mechanical device. This proposed handles can generate the three angle motion of wrist such as the roll, pitch and yaw. This proposed device has some features that this device can be implemented with lower costs than electronic devices and can be used whatever the wounded hand is right or left by selecting the lever. Further, when the patient has the rehabilitation exercise intent, the patients can easily use the proposed upper limb rehabilitation devices without the aid of the rehabilitation therapist the energy source is the normal hands of the patients.
Kinematic Design Consideration Based on Actuator Placement of Five-Bar Planar Robot for Arm Rehabilitation
Authors: Choi Jung Hyun , Shin Dong Hwan , Park Tae Sang , Jeong Choong Pyo , Moon Jeon Il , An Ji Nung
Published: August 2014

In the design of upper limb rehabilitation robots, critical issues to be considered are large workspace with minimum singularities to cover enough patients’ upper limb range of motion and higher manipulability for the patients to easily and freely move their arm with applying almost the same force to every direction in a given posture. This paper presents an analysis of the suggested kinematic design considerations of five-bar planar mechanism according to the actuator locations. A comparison between two different five-bar linkage types is given. Finally, several open challenges for the applicability of five-bar planar mechanisms are discussed from the kinematic point of view to upper limb rehabilitation robots.
Study of Adjusted Rapid Upper Limb Assessment for Evaluating of Rehabilitation Effects
Authors: Jeong Choong Pyo , Shin Dong Hwan , Park Tae Sang , Choi Jung Hyun , Moon Jeon Il , Yang Seung Han
Published: August 2014

As it is well-known, the stroke is known to be a cerebrovascular disease due to circulation disorders. Physical disabilities do remain due to nerve damages after strokes occur. These physical disabilities of the patient can be reduced by the rehabilitation treatment. This effect of rehabilitation appears with improvements of motor function. In order to evaluate the improvements of this motor function, therapists have used Fugl-Meyer assessment method (FMA). FMA method consists of fifty command motions such as thirty three command motions for motor function’s assessment of upper limbs and seventeen command motions for lower limbs. Further FMA method suggests three scores per each command motions. So to speak, in the FMA method, if the patients perform perfectly a given command motion, then they receive 2 points in a given command motion. Also if the patients cannot perform, they receive 0 point. Finally, if the patients perform partially, they receive 1 point. FMA method has a limit that cannot suggest exact assessments of the recovering patients. For the example, improvements of motor function of a patient cannot be evaluated from the initial stroke to full recovery. So it is hard to accurate diagnosis about patient's improvement. On the other hands, rapid upper limb assessment (RULA) method is suggested to evaluate the fatigue of muscle in a working environment. This RULA method suggests more detailed and quantitative assessment with diagnostic approaches than FMA method.
Evaluation of Running Safety for Railway vehicles Based on Vibration Acceleration of Bogie
Authors: Ham Young Sam
Published: August 2014

The lexical meaning of derailment shall be the wheels of trains going off the track and it is an important factor for the running safety of railway vehicles. For the measurement of interaction forces between the wheel and the rail, wheel set is used with normal method and the vibration accelerometer is used with simplified method to assess the safety of a railway vehicle in the derailment process. The result has been recorded by measuring vibration acceleration.
Experimental Investigation of Cell Cloning Efficiency after Optical Trapping
Authors: Taguchi Kozo , Hayashi Takuya
Published: August 2014

In this paper, chemically etched axicon fiber was investigated for laser trapping of micro-object dispersed in liquid. We fabricated axicon micro lenses on a single-mode bare optical fiber by selective chemical etching technique. The laser beam from fiber axicon microlens was strongly focused and optical forces were sufficient to move a microorganisms and biological cells without physical contact. In our experiments, several different lasers with various wavelengths were used as light sources. From these experimental results, it was found that laser wavelength was very important parameter for cell trapping and laser wavelength should be selected to avoid absorption by cells in order to prevent thermal degradation and damage to the cells.
Analysis and Optimization of a Vibration Isolation Platform Based on 6-DOF Parallel Mechanism
Authors: Yi Teng Da , Li Bing , Wang Nan
Published: August 2014

In this paper a 6-DOF(Degree of Freedom) vibration isolation platform with structural configuration of 3CPS (3 Cylindrical-Prismatic-Spherical)-1UPS (1 Universal-Prismatic-Spherical) parallel mechanism is proposed. Firstly, the dynamic model is developed through virtual work principle. The transfer function and the complex frequency response function were obtained from the dynamical equation. Then, 36 amplitude frequency diagrams are obtained from the frequency response function. By analyzing the 36 amplitude frequency diagrams, 10 vibration coupling terms were chosen. The range of the spring stiffness coefficient and the range of the damping coefficient of the magneto-rheological damper are determined by analyzing the acceleration transmissibility of the 10 vibration coupling terms. At last, an integrated optimization combining structural and controller optimization is developed. The optimal parameters of the parallel mechanism are obtained through Genetic Algorithm (GA). This work is significant for the prototype design and verification of the vibration isolator.
A New Method of Reducing the Measurement Blind Area for MPS
Authors: Deng Chao , Kang Yi Hua , Zhou Qian , Li Hui
Published: August 2014

The magnetostrictive position sensor (MPS), which can be used to detect the absolute position of motion objects in a coordinate system, is widely used in industry. It is especially applicable to the conditions of greasy dirt, oil and water. As an important disadvantage for MPS, the measurement blind area (BA) occurs due to the induced electromotive force (EMF) oscillation when the magnetic field of excitation pulse passes the receiving coil. A new structure with two coils is proposed in this paper. Two signals can be obtained by each coil, respectively, and the BA will be improved by different operations between two signals. Finally, the validity of this approach has been proved by experiments.
Study on Dynamic Measurement of Plane Distance
Authors: Wang Wei Chen , Chen Ding , Gao Hong Tang , Yang Zi Ben
Published: August 2014

Step gauge is the most typical multiple target standard of plane distance with a wide range of applications. The calibration of step gauge is, however, difficult because of its unique structure. In this paper, a new method for measuring plane distance is presented. The principle of light-section microscope is used in accurate positioning of the planes being measured. Then the optical interferometry techniques are used to realize continuous dynamic measurement of the plane distance. Based on this method, a novel optical probe is built and installed on a laser interferometer for length measurements. A series of experiments were carried out for determining the accuracy of positioning the optical probe and repeatability of the measuring system. Experimental results show that measurement repeatability is better than 16 nm, and measurement uncertainty (k=2) is less than 0.03 μm + 1.0×10-6L, for a total length of L being measured in micrometers.
Quantitative Defect Detection inside Metal Casting Specimens by Means of MFES
Authors: Nagata Shoichiro , Sakamoto Takemi , Enokizono Masato
Published: August 2014

An NDE measurement for internal defects of metal casting products is presented. The internal defects are often made in the manufacturing process of metal casting. From the view point of non-destructive evaluation (NDE), it is very difficult to make artificial defects that simulate actual internal defects. Therefore, we prepared a lot of metal casting samples that may include defects, and investigated the relation between the defect dimensions and the spectrogram that were generated by Multi-Frequency Excitation and Spectrogram Method (MFES).
Joining of Tubular Parts by Electromagnetic Forming; Experimental Investigations
Authors: Rácz Pál , Göbl Nándor , Horváth Daniel , Mamalis Athanasios G.
Published: August 2014

Electromagnetic forming is a high speed forming process, wherein the forming pressure is created by high energy density electromagnetic pulse. Besides direct shaping there are other application areas as well, so electromagnetic plastic forming is a potential field of creating joints between tube and rod-like components. Connecting components of dissimilar materials is an increasing demand in the manufacturing process of structures in the automotive industry. The application of new technologies, such as electrodynamic, especially electromagnetic forming, is a possible method to satisfy these demands. The article summarizes the most important fundamentals of electromagnetic forming; in particular, tube-rod joints, the main types of such joints; interference-fit and form-fit joints are described. Experiments, which were carried out producing tube-rod joints with electromagnetic forming, are also introduced. A new type of form-fit joints for tube-rod connections has been developed, which can withstand not only tensile loads but also torsion. Experiments and mechanical tests have proved the applicability of this kind of joints.
An Open Sample Measurement System for Soft Magnetic Material AC Characterization
Authors: Loizos George , Niarchos Dimitris
Published: August 2014

A highly sensitive open sample measurement system for soft magnetic strips, ribbons and films is described. It is a system built on a PXI platform combining PXI modules for control signal generation and data acquisition. The physical signals are digitized and the respective data streams are processed, presented and recorded in LabVIEW 7.0.
Joining of Tubular Parts by Electromagnetic Forming: Computational Investigations of Strength
Authors: Gonda Viktor , Rácz Pál , Horváth Daniel , Mamalis Athanasios G.
Published: August 2014

A frequent application of electromagnetic forming in the industry is joining by electromagnetic compression of tubular parts. The goodness of the joints is determined by the strength of the joint, and it is considered excellent if it reaches the strength of the weaker material pair. Strength of these joint are generally tested for tensile and torsion loadings. In order to increase strength, one or more horizontal and/or radial grooves can be fabricated onto the male joining pair to utilize form fitting besides interference fit. In the present paper, the strength of the joint is studied by finite element simulations.
Vector Magnetic Characteristic Technology for Developing High Efficiency Machines in Oita National Project
Authors: Enokizono Masato
Published: August 2014

In this paper we will discuss about the development of IE4 level motor proposed by IEC, which is new target for international efficiencies. Efficiency classes IE1-IE4 are defined in international standard IEC 60034-30. The draft version of IEC 60034-31 defines the new class IE4. The IE-codes replaces the former voluntary Eff classification of electric motors as shown in Table 1. The Eff classes are based on a voluntary agreement between the EU and the CEMEP in 1998.Table 1 Minimum energy performance standards for electric motors.
Simplified Calculation Method of Planar Coil Impedance Considering the Eddy Current Distribution by Using Finite Element Method
Authors: Wakiwaka Hiroyuki , Ito Daisuke , Tashiro Kunihisa , Yajima Hisashi , Manta Yuji , Kanazawa Takehiko , Fujiwara Nobuhiro
Published: August 2014

Eddy current sensors have various uses. However, there are few studies which show theinfluence of a conductor on the impedance of a detector coil using theoretical formulae. This papershows a simplified calculation method for impedance of a planar coil while considering the influenceof eddy current. An eddy current distribution in a metal plate facing to planar coil was calculatedusing finite element method. It assumed the metal plate to be a one-turn coil that can change shape.Therefore, the impedance of a planar coil considering the influence of the eddy current can beestimated from an equivalent circuit. In addition, calculations were simplified by estimating mutualinductance between the planar coil and the metal plate from an area ratio. This simplified calculationmethod can estimate impedance with the same accuracy as finite element method. The calculatedvalue agrees to within ±2.44 % of the measured value. The computation time was shortened by 1/20.Therefore, it can be immediately estimated how each parameter of a planar coil or a target influencesthe characteristic of the eddy current sensor. This simplified calculation method is useful for anoptimum design of an eddy current sensor.
Analysis of Three Phase Linear Synchronous Motor Distortion Factor
Authors: Nakaiwa Koichi , Wakiwaka Hiroyuki , Tashiro Kunihisa
Published: August 2014

The relation between the Electro Motive Force (EMF) and Total Harmonic Distortion (THD) was compared and verified by magnet arrangement. Using Halbach array, thrust was more increase by change of magnet arrangement. Moreover, the variable trend of cogging and THD by magnet ratio and magnet form change was checked.
Frequency Analysis of Semi-Active Tuned Magnetic Fluid Column Damper with Two Electromagnets
Authors: Ikari Kazuki , Masuda Hideaki , Oyamada Toshiyuki , Sawada Tatsuo
Published: August 2014

A new semi-active tuned liquid column damper (TLCD) that uses magnetic fluid as its working fluid (MF-TLCD) is presented. An MF-TLCD alters the natural frequency of the magnetic fluid column that forms the resident liquid inside the MF-TLCD by applying a magnetic field. We investigated the damping characteristics of an MF-TLCD equipped with two electromagnets, and also the transition of the natural frequency, which is strongly related to the damping performance. The coupled structure-MF-TLCD system was investigated both experimentally and by numerical analysis. The momentum equation of an MF-TLCD and its numerical solution are presented. The numerical results are validated by comparison with experimental results.
Green Energy from Road Vehicle Shock Absorber
Authors: Zádor István , Török Ádám , Rácz Pál , Vajda Istvan
Published: August 2014

It is still a difficult problem to solve for a suspension system simultaneously to hold the body of the car in comfort and to execute the requirements of other safety systems like ABS, ESP, steer-by-wire, etc systems. Passive suspension systems are unlikely to provide a solution, the introduction of semi-active suspensions in the practical use is necessary. A possible solution could be a permanent magnetic (PM) synchronous tube generator, which can operate as a controllable shock absorber parallel with energy recuperative operation. Designer software is realized, to calculate the geometrical and electrical parameters of permanent magnetic (PM) or high temperature superconductor (HTS) magnets for arbitrary vehicle suspension systems
Effect of Power Line Conductor Resistance-to-Reactance Ratio on Voltage Magnitude during Two-Phase Faults at Electric Energy Grids
Authors: Moschakis Marios , Prousalidis John , Tsikalakis Antonis G. , Karapidakis Emmanuel S.
Published: August 2014

This paper deals with the effect of power line impedance characteristics on the retained voltage magnitude after a two-phase fault at electric power distribution or transmission networks. Specifically, the effect of resistance-to-reactance (R/X) ratio of power line conductors or cables on voltage magnitude during two-phase faults is studied with analytical mathematical expressions. The basic aim of this investigation is to create a tool for the automatic recognition of the type and the location of faults on electric power networks.
Relation between Dynamic Pressure and Displacement of Free Surface in Two-Layer Sloshing between a Magnetic Fluid and Silicone Oil
Authors: Ishiyama Takayoshi , Kaneko Shunsuke , Takemoto Shinichiro , Sawada Tatsuo
Published: August 2014

We performed experiments regarding two-layer sloshing, using a magnetic fluid and silicone oil, and measured the dynamic pressure change using pressure transducers. We also investigated displacements of the free surface by comparing it with the dynamic pressure, clarifying the relation between them, both in the presence and absence of a magnetic field.
Investigation of Magnet Arrangements in Double Layer Interior Synchronous Permanent Magnet Motor over Wide-Speed Range for Electric Vehicle Applications
Authors: Sarigiannidis Athanasios G. , Beniakar Minos E. , Kakosimos Panagiotis E. , Kladas Antonios
Published: August 2014

In this paper, the magnet arrangement for a manufactured Double Layer Interior Synchronous Permanent Magnet Motor (DLISPMM) for Electric Vehicle (EV) applications is investigated. In a first step, the manufactured motor is optimized for its nominal condition, by using a particular design of experiment (DOE) method. In a second step, a comparative analysis for the two types of DLISPMMs for a wide speed range operation is performed, by using a parametric Finite Element (FE) model, for calculation of the main machine characteristics, in conjunction with a convenient dynamic model, considering magnetic saturation, for implementation of field weakening control. The initial linear and the final, considering magnetic saturation, dynamic models are evaluated. Finally, the initial and final designs are compared in terms of the main operating characteristics for both nominal low speed and high speed field weakening operation.
Micro/Nano Surface Texturing in Si Using UV Femtosecond Laser Pulses
Authors: Al Naimee K. , Scully P.J. , Abdalah S.F. , Liang S. , Meucci R. , Arecchi F.T.
Published: August 2014

A fast laser texturing technique has been utilized to produce micro/nanosurface textures in Silicon by means of UV femtosecond laser. We have prepared good absorber surface for photovoltaic cells. The textured Silicon surface absorbs the incident light greater than the non-textured surface. The results show a photovoltaic current increase about 21.3% for photovoltaic cell with two-dimensional pattern as compared to the same cell without texturing.
Finite Element Analysis of Precipitation Effects on Ni-Rich NiTi Shape Memory Alloy Response
Authors: Cox Austin , Baxevanis Theocharis , Lagoudas Dimitris C.
Published: August 2014

Thermomechanical properties of precipitated NiTi shape memory alloys are investigated using the finite element method. The precipitated material microstructure is explored using a representative volume element with embedded Ni4Ti3 precipitates. Features such as precipitate coherency and distribution of Ni within the matrix due to the precipitation process are individually explored and characterized. Changes in the material’s macroscopic thermomechanical response due to this precipitation are determined.
Magneto-Optical Study on Transparent Lanthanide Glasses in Pulsed High Fields up to 30T
Authors: Yamada Koji , Shimoji Hiroyasu , Luo Jiao Lian , Ohta Kimihiro , Todaka Takashi , Enokizono Masato
Published: August 2014

Magnetizations and optical Faraday effects have been intensitvely studied in transparent glasses of almost all Lanthanide elements with 20mol % in pulsed magnetic fields up to 30T in the temperature range between 1.8K-RT. The internal effective fields were investigated by observing Verdet constants as a function of applied fields and as a function of magnetizations in the wavelength range between 400nm and 2600nm, intensively for Nd, Pr , Tb and Dy glasses respectively. We obtained a magnet of Dy (30mol%) glass with optically transparent and adhesive to conventional magnet at the room temperature. The magnetizations of these glasses showed paramagnetism at the room temerature and showed super-paramagnetim at cryogenic temperatures below 4.2K.
Diversity and abundance of arthropod by-catch in semiochemical-baited traps targeting apple clearwing moth (Lepidoptera: Sesiidae) in organic and conventional apple orchards in British Columbia, Canada
Authors: Aurelian V. Marius , Evenden Maya L. , Judd Gary J.R.
Published: August 2014

Apple clearwing moth (ACM),Synanthedon myopaeformis(Borkhausen) (Lepidoptera: Sesiidae), is an invasive species and destructive pest of commercial apple trees in British Columbia (BC), Canada. Mass trapping with Concord grape juice and sex pheromone is being developed as an organic pest management tactic. We quantified the diversity and abundance of arthropod by-catch in these traps during the 2009 flight (13 June–31 July) of ACM. Paired traps were deployed in organic and conventionally managed apple orchards planted using different tree densities representing the extremes of the current BC apple industry. Using seasonal by-catch and community-level statistical analyses we determined that family communities of arthropods caught in juice-baited and pheromone-baited traps differed significantly. Yellow juice-baited traps caught a greater variety of arthropod families in greater abundance than pheromone-baited yellow Unitraps®. We show that for each trap type, family communities caught in organic versus conventional orchards were significantly different. Organic orchard management affected abundance of some beneficial taxa, but the sign of the difference depended on the taxon examined (e.g., ladybeetles increased versus lacewings declined). Tree density had no effect on by-catch. Managing ACM by mass trapping may be detrimental to ecosystem services because many nontarget beneficial species are caught. A balanced risk-to-benefit approach should be taken before this technology is widely implemented against ACM.
Lower levels of serum high-density lipoprotein cholesterol are associated with a worse Duke treadmill score in men but not in women
Authors: Erkan AF , Ekici B , Demir GG , Töre HF
Published: August 2014

Background:

High-density lipoprotein cholesterol (HDL-C) levels are inversely related to the atherosclerotic burden and are higher in women than in men. We aimed to investigate the sex-specific relationship between serum HDL-C levels and the Duke treadmill score (DTS) in this study.

Materials and Methods:

A total of 111 patients (59 men, 42 women) with suspected coronary artery disease (CAD) who underwent exercise treadmill test (EST) were included. Fasting blood samples were obtained for the assessment of serum lipid levels. DTS was calculated for each patient based on EST findings including ST segment deviation and symptoms.

Results:

Patients were categorized into a moderate to high risk group based on the DTS score (group-I: 38 patients) and a low risk group (group-II: 63 patients). There was a significant positive correlation between serum HDL-C levels and DTS (r = 0.230; P=0.021). The mean HDL-C level was significantly higher in group-II relative to group-I (49.25 ±11.21 vs. 44.43 ± 11.18, respectively, P = 0.04). An HDL-C level less than the cut-off value of 41.39 mg/dL predicted a moderate to severe risk DTS with 65% sensitivity and 69% specificity in men (area under curve = 0.732, P = 0.004), but not in women (area under curve = 0.505, P = 0.958). After adjustment for traditional CAD risk factors (age, sex, and smoking status), the relationship of DTS to HDL-C remained significant. (P = 0.030; adjusted OR = 0.948 [95% CI, 0.904-0.995]).

Conclusion:

Low HDL-C levels may be associated with a moderate to high risk Duke treadmill score in men, but not in women. Further research is required to clarify the sex-specific relationship between HDL-C and DTS.