bluuebunny/crossref_metadata_2025 huggingface dataset:
Simulation of Lamb Wave Propagation in Composite Structures Based on the Finite Element Stacked Shell Method
Authors: Lampeas George , Fotopoulos Konstantinos
Published: October 2016

Monitoring of structural integrity of a component is very important, especially for the damage sensitive laminated composite structures. Among the Structural Health Monitoring (SHM) techniques, the Acousto-Ultrasonic (AU) technology is very promising. However, the accurate simulation of Lamb wave propagation is a very demanding task, in terms of computational cost. In the present study, in the frame of Finite Element method, the stacked-shell methodology is proposed for the simulation of Lamb wave propagation in composite laminated panels. The results of the stacked-shell approach are initially evaluated with respect to experimental results; the method is subsequently applied to undamaged and damaged composite laminated panels, in order to assess its efficiency and accuracy in the simulation of Lamb wave-based damage detection techniques.
Structural Health Monitoring of Bonded Patch Repaired Composite
Authors: Lambinet Florian , Sharif Khodaei Zahra , Aliabadi M.H.
Published: October 2016

Bonded repair of composite structures still remains a crucial concern for the airworthiness authorities because of the uncertainty about the repair quality. This works, investigates the applicability of Structural Health Monitoring (SHM) techniques for monitoring of bonded repair. Active sensing method has been applied to two case studies: a sensorised panel impacted to cause barely visible impact damage (BVID) and repaired afterwards, the tensile and fatigue testing of a composite strap repair. In the first case, the previous sensors have been used to detect an artificially introduced damage. In the second case the failure of the adhesive during the tensile testing is used as basis of the load levels in the tensile-tensile fatigue test. In both cases PZT transducers have been used to monitor the bonded patch. An electromechanical impedance (EMI) and Lamb wave analysis have been carried out to check the overall integrity of the repair patch between. In both cases the state of the repaired composite was monitored successfully and reported.
Comparison of One-, Two- and Three-Dimensional Models of a Metallic Insert in a Composite
Authors: Herwig Alexander , Woidt Malte , Horst Peter
Published: October 2016

For a set of applications, thin metallic sheets are used in fibre composite materials to reach higher load introduction capacities. The paper deals with a simplified generic problem of this kind. The main subject is the comparison of results of three types of models, namely, a 1D-, 2D- and a 3D version. What can be shown is the fact that results are quite similar with respect to behaviour along the loading direction, but very different in the actual values.
The J-Integral for Gradient Theory of Piezoelectricity
Authors: Sladek Jan , Sladek Vladimir , Zhang Chuan Zeng , Tan Choon Lai
Published: October 2016

The size-dependent features concerning the mechanical behavior of the micro/nanoelectronic structures are well known from experiments. They are described by the strain-gradient effect in this paper since the classical elasticity theory fails to capture the size effect of the nanostructures. The electric field-strain gradient coupling is considered in the constitutive equations of the material and the governing equations are derived with the corresponding boundary conditions using the variational principle. The path independent J-integral is derived for fracture mechanics analysis of piezoelectric solids described by the gradient theory.
Helium Effects on 316L Austenitic Stainless Steel Fracture Mechanism
Authors: Villacampa I. , Chen Jia Chao , Spätig Philippe , Seifert Hans Peter , Duval F.
Published: October 2016

The most common fracture mechanism of nuclear reactor internals is irradiation-assisted stress corrosion cracking (IASCC). Its susceptibility at relatively low dose is dominated by conventional mechanisms such as radiation-induced segregation and radiation hardening. However, the aging of the nuclear fleet combined with the increase of their life-span reveals other mechanisms that could play an important role on IASCC susceptibility. A large amount of helium (He) can be accumulated in reactor internal components of pressurized water reactors (PWR) after long term operation. This occurrence could significantly increase (or even dominate) the IASCC susceptibility at high doses. He has been homogeneously implanted in an especially designed miniaturized specimen at 300°C up to 1000 appm. Slow strain rate tests (SSRT) results in high temperature air and in simulated PWR conditions indicate that homogenized, as-implanted He does not have a significant effect on IASCC up to 1000 appm under these test conditions.
Evolution of Crack Density in Cross-Ply Laminates - Application of a Coupled Stress and Energy Criterion
Authors: Kashtalyan Maria , García I.G. , Mantič Vladislav
Published: October 2016

The first damage mode to appear in continuous fibre-reinforced composite laminates subjected to in-plane loading is usually transverse cracking, i.e. matrix cracking in the off-axis plies of the laminate. Since the density of transverse cracks has a great influence on the subsequent failure steps like delaminations, it is important to be able to predict it accurately. In this paper, the evolution of crack density with increasing external load is predicted using a combination of the Coupled Criterion of Finite Fracture Mechanics and the Equivalent Constraint Model.
Experimental Test of Compressive Strength after Impact Damage of Natural Composite Laminate
Authors: Park Hyun Bum
Published: October 2016

In this study, structural design and analysis of the automobile bonnet is performed. The flax/vinyl ester composite material is applied for structural design. The Vacuum Assisted Resin Transfer Molding (VARTM) manufacturing method is adopted for manufacturing the flax fiber composite bonnet. A series of flax/vinyl ester composite panels are manufactured, and several kinds of specimens cut out from the panels are tested to obtain mechanical performance data. Based on this, preliminary structural design of the automobile bonnet is performed. Finally, this study is to investigate the residual compressive strength of the flax/vinyl ester laminate due to impact damages. Through investigation on compressive strength, design allowable of flax/vinyl ester laminate is determined by the experiment to address design criteria of the composite structure.
Interlaminar and Intralaminar Fracture Behavior of Carbon Fiber Reinforced Polymer Composites
Authors: Haldar Sandip , Lopes Claudio S. , Gonzalez Carlos
Published: October 2016

Interlaminar and intralaminar fracture behavior of carbon fiber reinforced composites have been experimentally studied. Unidirectional, woven reinforcement and thermoplastic and thermoset polymer matrix laminates have been characterized using double cantilever beam (DCB) and end notch flexure (ENF) specimens for Mode-I and Mode-II fracture toughness, respectively and compact tension (CT) specimens for intralaminar fracture. AS4/PEEK, AS4/8552 and AGP193PW/8552 laminates have been characterized in this study. The fracture toughness determined from the experimental data could be related to the constituents and reinforcements. It has been observed between the two UD laminates, AS4/PEEK exhibit higher fracture resistance under both interlaminar and intralaminar fracture. Woven reinforcement is found to show higher mode-II interlaminar fracture toughness.
Effect of Mean Stress on 2A12-T4 Aluminum Alloy under Tension-Torsion Constant Amplitude Loading
Authors: Liu Tian Qing , Shi Xin Hong , Zhang Jian Yu
Published: October 2016

Fatigue tests have been carried out to investigate the effects of mean-stress and phase-difference on the tension-torsion fatigue failure of 2A12-T4 aluminum alloy. The results show that for fully reversed tension-torsion loading, the fatigue life increases with the increase of phase angle, but the fatigue life decreases with the increase of phase angle, when mean-stress exists, both for shear mean-stress and normal mean-stress. Fracture appearance shows that the crack initiation is on the direction of maximum shear stress amplitude plane. Critical plane criteria based on the linear combination of the maximum shear stress amplitude and maximum normal stress are studied and further discussion on the drawbacks of this kind of criteria are performed.
Effects of PVD DLC Coating on 7075-T6 Fatigue Strength at High and Low Number of Cycles
Authors: Baragetti Sergio , Gerosa Riccardo , Villa Francesco
Published: October 2016

Despite its high tensile strength and its brilliant fatigue behaviour, 7075-T6 aluminium alloy usage is dramatically reduced, due to its sensitivity to corrosion and its poor surface characteristics. In order to be adopted for advanced applications in the aeronautic, automotive and maritime fields, as well as in further innovative applications, 7075-T6 resistance must be improved. Controversial results are found in literature on coated 7075-T6 fatigue strength, due to the complex mechanical interaction between the substrate and the coating, and the high temperatures involved in the coating process. In the present work, testing on rotating bending fatigue (R = -1) 7075-T6 uncoated and PVD DLC coated specimens has been conducted. Different stress levels were considered, to assess the impact of the applied stress on the fatigue life of the substrate-coating system. SEM characterization of the fracture surfaces has been performed, to investigate the influence of the coating on the fracture mechanism
Investigations on the Fracture Toughness of Electron Beam Welded Steels
Authors: Hesse Ann Christin , Nitschke-Pagel Thomas , Dilger Klaus
Published: October 2016

Beam welded joints made from fine grain steels show martensitic micro structure, high weld hardness and thus low toughness in the weld seams. At the same time there is a risk for these welds to have crack-like defects that cannot be detected during the production and which grow due to cyclic loading. If such structures are used in areas with low ambient temperatures, it may come to brittle failure of the component.
To secure components against such failure, fracture mechanic tests were carried out on electron beam welded SE(B)-samples made from S690QL and S960QL and the J-integral was determined. In order to describe the scattering of the results in the temperature transition region the results were evaluated by means of the Master Curve concept in accordance with ASTM E 1921. Afterwards the reference temperature in the transition range, T0, was determined and correlated with the T27J- temperature of Charpy V-notch tests.
Mixed Mode Failure Criterion for Random Composites Using a Finite Element Model
Authors: Jamali J. , Sharifi P. , Mahmoodi M.J. , Mourad A.H.I. , Wood J.T.
Published: October 2016

In this research mixed-mode fracture behaviour of glass fibre/epoxy composite with randomly distributed glass fibres investigated. Various modes of loading were applied. Compact tension shear (CTS) fixture with different loading angles were used. The testing is used to measure the fracture toughness. Critical strain energy release rate (CSERR) of the composite was then calculated using the measured fracture toughness. A model is proposed to predict the value of CSERR based on the constituents and interfacial properties. Different failure mechanisms are considered in developing a criterion. To derive the criterion a FE model is used to determine the amount of energy released during the fibre pull out which is major part of energy dissipation.
Cylindrical Grinding by Structured Wheels
Authors: Daneshi Amir , Azarhoushang Bahman
Published: October 2016

Structuring of the grinding wheels is a promising method to reduce the forces involved in grinding, especially during dry grinding. In this paper, one of the methods of grinding wheel structuring is presented. The structuring process was modeled to find the corresponding dressing parameters for the desired structure dimensions. The cylindrical grinding operation with the structured wheels was simulated to produce a spiral free ground surface. Afterwards, the dry grinding experiments with the structured and non-structured wheels were carried out to evaluate the efficiency of the structured wheels. The results revealed that the grinding forces can be reduced by more than 50% when the grinding wheels are structured, while the surface roughness values increase by 80%.
Cutting Performance of PCD Tools Improved by Ultraviolet-Ray Irradiation Polishing
Authors: Goto Kenta , Izumi Yasuo , Sakamoto Takeshi , Kubota Akihisa , Touge Mutsumi
Published: October 2016

The polycrystalline diamond (PCD) is made of sintered diamond fine powder with binder material, and shows clear isotropic characteristics and high toughness without frequent cleavage. As the PCD cutting tools require relatively low tool cost compared with single crystal diamond tools, they have wide applications as the precision cutting tools with the high abrasion resistance. The more sharp or complex shapes of PCD cutting tool are deeply expected even though they have the machining difficulties. In this study, the ultraviolet-irradiation polishing of single crystal diamond substrates developed in our laboratory (abbreviated as UV-polishing in this paper) was applied to realize advanced PCD tools with ultra-sharp or chamfered cutting edges. Firstly, the UV-polishing properties of PCD substrate were investigated, and high-quality polished surface with 2.6 nmRa was obtained. Secondly, the UV-polishing was applied to the precision polishing of the flank face of PCD cutting tool, and an ultra-sharp cutting edge was finally achieved. The chamfered cutting edge with desired angle and width was additionally formed by the UV-polishing to suppress the chipping left on the sharpened cutting edge. The tool wear of chamfered PCD cutting tools could be reduced almost by half to the sharpened tool under high-speed cutting of high silicon-aluminum alloy.
Study on Ultraprecision Polishing of Sapphire – Effects of Crystal Orientation on Polishing Characteristics
Authors: Okada Mutsumi , Suzuki Hirofumi , Suzuki Toshikazu , Higashi Yasuo , Aoyagi Shinobu
Published: October 2016

In the telescopic interferometer KAGRA (Large-scale Cryogenic Gravitational wave Telescope), the ultraprecision mirror made of sapphire (α-alumina) is required to polish. The focal length of the mirror is 7 km and it must be finished by polishing after grinding. In order to polish the mirror precisely, polishing characteristics of the sapphire must be researched. In this study, the polishing characteristics are examined and the dependence of the crystal orientation on the polishing rates is studied. In the experiments, sapphire wafer is polished by using rotational small tool and SiO2 abrasives.
Research Status of the Pendulum High-Speed Single Grain Test
Authors: Shi Yan , Jiang Feng , Yan Lan
Published: October 2016

This paper has designed the pendulum type in high speed of single grit cutting equipment, discussed the material process of deformation and failure mechanism. During the investigation, compared with the abrasive cutting export and cutting entry based on the MP tool coating, which is badly broken when the cutting depth increases gradually at the entrance, and is broken less when the cutting depth gradually decreases at the export. Researched the MP tool coating of Surface and subsurface damages by indentation and scratching, it has demonstrated that on one side of the groove has appeared the crack and with severe plastic flow phenomena by scratching, and by indentation the cracks of the groove is not produce on both sides and bottom, but at the bottom of the trench existing extrusion phenomenon.
Wear of Monolayer Brazed Diamond Beads in Wire Sawing of Granite
Authors: Huang Guo Qin , Huang Hui , Guo Hua , Zhang Mei Qin
Published: October 2016

The wear behavior of monolayer brazed diamond beads was investigated during wire sawing of granite. Diamonds were bounded onto the beads by brazing in vacuum. Brazed beads were abrasive sawed on a wire sawing machine and the wear of the brazed diamond beads were traced and observed by using a digital microscope. The results reveal that the wear of root fractured, characterized by breaking off grit at its bonding level, was the fatal failure of the cutting ability of grit as well as the main wear behavior of brazed grits on brazed bead.
A Mechanical Model of Diamond Wire Sawing of Steel Structures
Authors: Denkena Berend , Grove Thilo , Tatzig Lukas
Published: October 2016

Wire sawing with diamond tools is a highly flexible cut-off grinding process with regard to machinable component structure and composition. Nowadays, it is deployed in many fields of application e.g. the dismantling of nuclear or industrial plants. Here, steel has to be cut which results in lower productivity and tool life compared to the conventional processing of natural stone. To ensure a properly designed process the mechanical and thermal tool loads have to be known in advance. This paper presents an analytical model that predicts the mechanical load as a function of the process parameters.
Development of a New Truing Device Based on Electro-Contact Discharge Machining for Metal Bond Grinding Wheels
Authors: Mizuno Masahiro , Karibe Akira , Yoshihara Nobuhito , Nishikawa Naohiro , Iyama Toshiro
Published: October 2016

Metal bond grinding wheels can retain their shape and size under extreme grinding conditions. On the other hand, it is difficult to true them accurately and efficiently due to the severe wear of truing tools. To solve the problem, this paper proposes a new truing device based on electro-contact discharge machining. The device is designed so that the position of the electrode working face remains unchanged even if the electrode is worn. Some truing experiments were carried out using a prototype truing device for a metal bond diamond wheel of grain size #1000 under dry conditions. As a result, relatively high truing accuracy has been achieved in combination with an additional truing by a GC stone.
Laser-Profiling of Metal-Bonded Diamond Grinding Wheels
Authors: Zahedi Ali , Azarhoushang Bahman
Published: October 2016

Conditioning challenges of superabrasive grinding wheels cause a barrier to the extensive applications of these tools. These concerns are more pronounced in the case of conditioning of metal-bonded superabrasive grinding wheels owing to their high bond hardness. Laser ablation has been used as a promising method for conditioning of such tools. In this research an ultrashort pulsed laser was used for efficient profiling of metal-bonded diamond grinding wheels. In order to assess the laser-profiling technique, the experiments were aimed to generate precise profiles which are rather too difficult or impossible to generate with conventional methods. Convex and concave profiles with minimum radius of about 20 μm and 40 μm, respectively are produced successfully via laser conditioning.
Grinding of Riblets on Curved Paths
Authors: Denkena Berend , Grove Thilo , Harmes Jan
Published: October 2016

The grinding of riblets with multiple profiled grinding wheels is an efficient method to minimize the fluid friction on surfaces. In turbo machinery components, like pump impellers or compressor blades, the riblets must be ground with a curved tool path since the flow is rarely linear on such surfaces. This leads to angular errors in the generated riblet profiles and therefore requires the use of grinding wheels with smaller diameters. The tool wear increases due to lateral strain on the peaks of the grinding wheel. Consequently, the increased wear and the need of smaller tool diameters decrease the efficiency of the process. In this paper a structuring process with dicing blades was investigated in order to increase the economic viability of this process. A dressing operation for such tools is not necessary and thus reduces the non-productive time of the manufacturing process. Furthermore, profile tip wear has no negative effects on the aspect ratio of the generated riblets since the riblet geometry is determined by the thickness of the dicing blades.
New Evaluation Method of Polishing Pad Property for Estimating Edge Roll-Off of Silicon Wafer
Authors: Obayashi Yuma , Satake Urara , Enomoto Toshiyuki
Published: October 2016

With the ever-growing demand for further increase in the integration density of semiconductor devices, silicon wafers as the substrates for most devices are required to be extremely flat. In particular, it is strongly required to suppress edge roll-off, which seriously deteriorates the surface flatness near the wafer edge during polishing process in the final stage of the wafer manufacturing. In this study, we investigate the properties of polishing pads required for decreasing edge roll-off and propose the evaluation method of the properties. Polishing experiments with silicon wafers and evaluation tests for polishing pads reveal that the proposed method can estimate the obtained edge surface flatness.
Relaxation of Thermal Residual Stress in Laser Irradiated Fused Silica by Annealing Process
Authors: Li Run Qiang , Yao Peng , Wang Wei , Wang Jun , Huang Chuan Zhen , Yang Zhi Hong , Liu Yue
Published: October 2016

To relax the surface residual stress of fused silica lens or windows irradiated by CO2 laser, it was proposed to treat it at high temperature above glass strain temperature in the traditional annealing process. However it is a time and energy consuming process, and a distortion will be introduced during the heat treatment. To deal with these problems, annealing temperatures lower than glass strain temperature were applied to the annealing process and a new scheme was designed in this paper. An numerical model was built to simulate the laser induced residual stress and optimize the stress variation in the annealing process. The surface stress of fused silica can be relaxed and deformation induced by heat treating can be ignored.
Preparation and Research on Microwave Plasma Chemical Vapor Deposition Diamond Films on SiC Substrate
Authors: Wang He , Wu Yu Hou , Zhang Ke
Published: October 2016

Diamond films and diamond/graphite composite films have excellent wear resistance, it can be used as the protective coating to effectively improve the parts life and performance. The micro crystalline diamond films, nanocrystalline diamond films and diamond/graphite composite films were prepared on sic substrate by microwave plasma chemical vapor deposition on different power, pressure and CH4 concentration growth parameters. The films surface characteristics were research by SEM and Raman spectrometer. The results indicate that the diamond grain size and content decreased and graphite content increased with CH4 concentration increasing on constant microwave power and cavity pressure; the diamond grain size decreased and graphite constant increased with cavity pressure increasing on constant microwave power and CH4 concentration.
Effects of Relative Velocity on Grinding Performances under Si Wafer Rotary Grinding
Authors: Kusuyama Jumpei , Kitajima Takayuki , Yui Akinori , Ito Toshihiro
Published: October 2016

For the backgrinding of semiconductor devices, a rotary grinding process is indispensable for achieving the required wafer thickness. The relative velocity between the grinding wheel and the wafer is maximum at the periphery of the wafer and minimum at the center of wafer. Generally, the grinding performances are discussed in terms of the ratio of the rotational speeds of the grinding wheel and the wafer. However, it is not possible to use this ratio to determine the grinding conditions for different wafer sizes grinding as this ratio does not show the difference in relative velocity. Therefore, a new relative velocity ratio was defined in this study. Then, the Si wafer grinding was performed to investigate the effect of the surface roughness and the power consumption of the grinding wheel spindle on the relative velocity ratio.
Environment-Friendly Chemical Mechanical Polishing Slurry for SiC Wafer
Authors: Yuan Ze Wei , He Yan , Wen Quan , Du Hai Yang
Published: October 2016

In order to avoid the environmental pollution and the harm to body of traditional polishing slurries, an environment-friendly chemical mechanical polishing technology is proposed for SiC wafer in this study. With this method, SiC material is removed by utilizing the strong oxidability of nanotitanium dioxide particles in chemical mechanical slurry in the existence of ultraviolet. While, the oxidbillity will recede in absence of ultraviolet when the polishing process finishes. On the basis of investigating in the reaction mechanism between SiC and nanotitanium dioxide, the slurries are prepared for the environment-friendly chemical mechanical polishing technology. The results show that the ultraviolet-assisted CMP slurry has strong oxidation for SiC material. This method is high-efficient for polishing SiC wafer. The surface roughness is reduced to about Ra 0.1μm from Ra 0.818μm after polishing for one hour.
Surface Roughness and Topography Analysis in Precision Milling of 3J33 Maraging Steel
Authors: Yao Yang , Zhu Hong Tao , Huang Chuan Zhen , Zhang Dian Cong , Wang Jun , Zhang Pu , Yao Peng
Published: October 2016

In precision milling, the quality of surface finish is an important requirement for workpiece machined. Thus, optimization of cutting parameters is important for controlling the surface quality. In this study, the Taguchi method is used to find the effects of milling parameters on surface roughness in precision milling of 3J33 maraging steel. A model, which is based on the milling parameters and tool geometry, is also proposed in order to predict the surface topography. The experimental results show that milling speed has significant effect on the surface roughness among the milling parameters. Besides, tool geometry and material deformation play important roles in the surface topography.
Monitoring Method of Process Temperature and Vibration of Rotating Machining Tool with a Wireless Communication Holder System
Authors: Matsuda Ryo , Shindou Masatoshi , Furuki Tatsuya , Hirogaki Toshiki , Aoyama Eiichi
Published: October 2016

We developed a wireless communication holder system to monitor the process temperature and vibration of a rotating machining tool. This report presents an estimation of the process temperature in end-milling and the chatter vibration when boring with it. The thermocouple is set in the end-mill tool to measure the process temperature, and the MEMS accelerometer is set in the boring tool to measure the chatter vibration. We also present an investigation of the end-mill temperature observed using infrared thermography and the vibration of the spindle using a traditional accelerometer. The proposed holder system was found to be effective to estimate the process monitoring of the rotating machining tools.
Influence of Wheel Position Parameters on Flute Profile of Micro-Drill
Authors: Zhang Su Yan , Liang Zhi Qiang , Wang Xi Bin , Zhou Tian Feng , Jiao Li , Yan Pei
Published: October 2016

Drill flute has a great influence on the drilling performance of micro-drill, and its profile largely depends on the grinding parameters, wheel profile and position. It is promising to obtain a desired flute profile with a standard wheel by adjusting the wheel position parameters. To investigate the influence of wheel position parameters on the flute profile, the micro-drill flute is simulated by MATLAB software considering the wheel installation angle and the offset distance from wheel origin to the drill blank origin, and the radial rake angle, flute width and chip evacuation capacity are quantitatively calculated to evaluate the flute profile. The simulated results show that the wheel installation angle has an obvious effect on the three performance parameters of flute profile, and the wheel offset distance only influences a parameter, i.e., the flute width evidently. The radial rake angle of drill flute increases obviously with the increased wheel installation angle, and decreases slightly with the increased wheel offset distance. With the decreased wheel installation angle, the flute width of drill flute increases causing the reduction of micro-drill strength but improvement of the chip evacuation capacity. With the increased wheel offset distance, the flute width also increases resulting in the reduction of micro-drill strength but no obvious change on chip evacuation capacity. Thus the wheel installation angle can be used as a main factor among the wheel position parameters to obtain the desired flute profile.
Quadrant Protrusion Measurement of Ultra-Precision Machine Tool by Real-Time Position Capturing Method
Authors: Duan Hao , Hosobata Takuya , Takeda Masahiro , MORITA Shinya , Yamagata Yutaka
Published: October 2016

This paper describes a development of a real-time position capturing method in which branched encoder signals are recorded in external data storage, to evaluate motion trajectories of the XYZ table on ultra-precision machine tool. The method allows the capturing with minimal modification to the machine: without any additional sensors. In the previous study we generated a non-axisymmetric aspherical optical element by XZC-axis simultaneous numerical controlled ultra-precision turning process with 2 μm form deviation, the reason of form accuracy degradation wasn’t identified. Using the developed system, motion accuracy of ultra-precision machine tool is confirmed. The machine tool moves along circular trajectory in three coordinate planes (XY, YZ and ZX) respectively. The rotation direction of circle is set clock wise and counter clock wise. The circle processing interpolation command by linear interpolation control code and circular interpolation control code. The results showed the effectiveness of the proposed method for performance evaluations of machine tools, by revealing the influence of trajectory parameters on the magnitudes of quadrant protrusions.
Development of a PCD Burnishing Tool and its Burnishing Performance
Authors: Iwai Manabu , Yamada Masahide , Chen Peter , Lin Bear , Suzuki Kiyoshi
Published: October 2016

In this study, a polycrystalline composite diamond (PCD) was adopted instead of a single crystal diamond as a burnishing tool. At first, EDM machinability was compared between two kinds of PCDs (10μm grain size), i.e. standard PCD (S-PCD) and electrically conductive PCD (EC-PCD (which was made of boron doped diamond particles). EDM machining time to make a hemispherical shape was 17 minutes for EC-PCD and 37 minutes for S-PCD. Further experiments were conducted with EC-PCD of different grain sizes such as 2μm and 5μm. As a result, the smaller the grain size of EC-PCD the higher the machining efficiency was. Surface roughness values of the EC-PCD after finish EDM were Rz=1.7μm for EC-PCD010, Rz=1.4μm for EC-PCD005, and Rz=1.2μm for EC-PCD002. As a result of burnishing a carbon steel bar (S45C, φ30mm) with the EC-PCD tool, the surface roughness value after machining was improved from 10μm to 1μm.
Optimization of the Removal Function of Dual-Rotation Magnetorheological Finishing
Authors: Zhang Yun , Feng Zhi Jing
Published: October 2016

Magnetorheological finishing (MRF) is an advanced polishing technique capable of rapidly converging to the required surface figure. In this article, dual-rotation MRF tool is used to generate centrosymmetric removal function that can be W-shaped or Gaussian-shaped. Using W-shaped removal function and Gaussian-shaped removal function respectively, this article compares the convergence of surface error by simulating the finishing process through iterative calculations. Furthermore, it compares mid-spatial-frequency surface error caused by the two removal functions, through 2D FFT and PSD estimation in the frequency domain. From simulation, this article proves that Gaussian-shaped removal function is more advantageous than W-shaped removal function. To solve the problem that the removal function obtained in dual-rotation MRF is W-shaped, this paper presents the method of adjusting the distance between the axes of self-rotation and co-rotation to secure Gaussian-shaped removal function. Finally, experiments have been conducted to demonstrate validity of the method.
Microencapsulation of Natural Antioxidant Compounds Obtained from Biomass Wastes: A Review
Authors: Valdés García Arantzazu , Garrigós Selva María del Carmen
Published: October 2016

Growing interest in biomass valorisation in recent years has led to an increasing research focusing on its high content in phytochemicals showing high potential health benefits related to their antioxidant, anti-inflammatory and antibacterial properties, among others. On the other hand, the demand for natural antioxidants in industry is continuously increasing to avoid the harmless character of some chemical additives and, also, to limit oxidation processes in the final material, such as in food and cosmetics; increasing consumer acceptance. However, the majority of them are usually sensitive to several factors such as oxygen, light, heat, enzymes, salts, and acid or alkali mediums which lead to losses of their activity and beneficial effects. As a consequence, microencapsulation technique has been proposed in last years as a way to enhance the stability, solubility and bioavailability of these compounds. In this chapter, phytochemical compounds classification followed by their main characteristics and properties are summarized. Also, microencapsulation techniques for phytochemicals are reviewed including processes for preparing microparticles, mainly focused on spray-drying method, for industry applications.
Preparation, Structural and Electrochemical Properties of PVC Based Magnesium Molybdate Ion-Exchange Composite Membrane for Desalination of Food Industry Waste Water
Authors: Ali Khan Mohammad Mujahid , Naushad Muhammad
Published: October 2016

The inorganic-organic hybrid composite membranes have played a rocking role for separation, concentration, purification and clarification of food industry wastewater. The separation of wastewater produced from post-treatment part of food industry processing using PVC based magnesium molybdate (MM) composite membrane was studied in this paper. The physicochemical and electrochemical studies of composite membrane shows better results from previously reported membranes. In this study, the transport number, mobility ratio and surface charge density of composite membrane play a dominant role for understanding the membrane mechanism and these parameters depend on the concentration of various univalent electrolytes.
Hydrolyzation of Edible Starches: Their Preparations and Properties
Authors: Grace Singan , Liew Kang Chiang
Published: October 2016

Starch is the most important polysaccharide and has become the major component of many food industries as well as textile, paper, cosmetic and certain industries that engage in adhesive, thickening, stiffening and gelling agents. However, native starch has limited function and therefore is recommended to modify its physical and chemical properties to meet the consumers’ needs. In this study, the native starch was chemically modified to determine its behavior and characteristics after using hydrolysis process of acid hydrolysis method. There were three types of starch that has been studied - potato, cassava and corn. These starches undergone hydrolysis process using hydrochloric acid and their characteristics were determinedthrough moisture absorption test and Fourier Transform Infrared Spectroscopy (FT-IR) analysis. For moisture absorption test, hydrolyzed starch tends to absorb more surrounding moisture than native starch. This behavior resulted from the increase of hydrophilic character of starch after being modified. The FT-IR analysis shows that hydrolyzed starch content got more hydroxyl group than the native starch due to the breakdown of hydrogen bond between the starch molecules after the acid hydrochloric treatment.
Ammonium carbonate loss rates from lures differentially affect trap captures ofRhagoletis indifferens(Diptera: Tephritidae) and non-target flies
Authors: Yee W. L.
Published: October 2016

Western cherry fruit fly,Rhagoletis indifferensCurran (Diptera: Tephritidae), is a pest of cherry (PrunusLinnaeus, Rosaceae) in western North America that can be monitored using traps baited with ammonia. However, ammonia-based attractants also attract non-target Diptera that clutter traps. Here, the hypothesis that ammonium carbonate (AC) loss rates from lures differentially affect numbers ofR.indifferensand non-target flies caught on sticky yellow rectangles in sweet cherry trees was tested in Washington State, United States of America. Ammonium carbonate loss rates were varied from seven-dram plastic vials hung ~1 cm above traps. A total of six experiments were conducted in which progressively lower AC loss rates within a range of 0.10–26.19 mg AC/hour were tested. For captures ofR. indifferens, no AC loss rate comparisons within 0.19–26.19 mg/hour differed, and captures were not reduced until losses were lowered to 0.10–0.13 mg/hour. In contrast, captures of medium to large (⩾5 mm long) non-target flies, which were mostly Sarcophagidae (Diptera), were reduced at a rate ~30 times higher, at 3.34 or 3.80 mg AC/hour. Results suggest that using lures with an AC loss rate of 0.19 mg/hour can maintain highR. indifferenscaptures while reducing non-target fly captures and thus can improve monitoring efficiency.
Management of Acute Osteomyelitis: A Ten-Year Experience
Authors: Helm Caitlin , Huschart Emily , Kaul Rajat , Bhumbra Samina , Blackwood R. Alexander , Mukundan Deepa
Published: October 2016

Osteomyelitis is an infection of the bone; proper management requires prolonged antibiotic treatment. Controversy exists as to when a patient should transition from intravenous to oral antibiotics. However, due to the high bioavailability of some oral antibiotics, optimal time to transition from high to low bioavailability antibiotics is a more valid consideration. Additionally, there are questions surrounding the efficacy of certain antibiotics, specifically trimethoprim-sulfamethoxazole (TMP-SMX), in treating osteomyelitis. After obtaining Institutional Review Board approval from both universities, a retrospective chart review was conducted, utilizing an author-created severity scale, on all patients seen by Pediatric Infectious Diseases at the Universities of Michigan and Toledo with an acute osteomyelitis diagnosis from 2002-2012. There were 133 patients, 106 treated successfully. Success was defined in this study specifically as treatment of <14 weeks without recurrence within 30 days of stopping antibiotics or permanent site disability. Seventeen patients were treated with TMP-SMX at comparable cure rates. Patients with pre-existing bone defects (noted in radiological reports), initial erythrocyte sedimentation rate (ESR) ≥70, hematogenous osteomyelitis with soft tissue extension, and skull osteomyelitis were associated with increased failure rate. Switch to low bioavailability antibiotics occurred, on average, at 3.5 weeks; however, switching before then was not associated with decreased cure rate. As prevalence of methicillin-resistant Staphylococcus aureus (MRSA), especially clindamycin- resistant MRSA, increases, TMP-SMX appears to be an acceptable antibiotic. There does not appear to be a minimum length of high bioavailability treatment required for cure. Prior bone defect, extensive infection, ESR≥70, or skull osteomyelitis may be indications for more aggressive management.
Aeromonas hydrophila Endocarditis with Ruptured Mycotic Aneurysm of Right Renal Artery
Authors: Pugliese Maria Elena , Falcone Marco , Oliva Alessandra , Faccenna Federico , D’Aluisio Denise , Morelli Sergio
Published: October 2016

Aeromonas hydrophila has been infrequently reported as a cause of infection in humans. It has been associated with a variety of clinical syndromes but Aeromonas-related endocarditis is extremely rare. We present the case of a 76- year-old diabetic patient who was admitted to our hospital due to severe lumbar pain resistant to nonsteroidal anti-inflammatory drugs accompanied by fever (up to 38.5°C). The vital signs were normal and the physical examination was unremarkable except for tenderness over right flank. Laboratory investigation showed a mild leukocytosis (white blood cell count of 11,360×106/L) with elevation of inflammatory markers. Cardiac ultrasound showed a large vegetation on the mitral valve. Abdominal computed tomogrpahy revealed a ruptured aneurysm of the right renal artery. Multiple sets of blood culture grew A. hydrophila.
Embolic stroke of undetermined source: a retrospective analysis from an Italian Stroke Unit
Authors: Masina Marco , Cicognani Annalena , Lofiego Carla , Malservisi Simona , Parlangeli Riccardo , Lombardi Alessandro
Published: October 2016

The new clinical construct of embolic stroke of undetermined source (ESUS) suggests that many cryptogenic strokes are related to minor-risk covert embolic cardiac sources or to embolus from non-occlusive plaques in the aortic arch or in the cerebral arteries. The authors analyzed the prevalence of ESUS in a real-life condition in Italy and compared the recurrence rates in cryptogenic strokes, cardioembolic strokes, and ESUS. The authors retrospectively reassessed according to ESUS criteria 391 consecutive admissions in a stroke unit where extensive diagnostic search was routinely performed. Recurrences in each stroke type within a 3-year follow-up period (mean time: 25.44 months - standard deviation: 9.42) were also compared. The prevalence of ESUS in the aforementioned cohort was 10.5%. All ESUS patients received antiplatelet agents. Warfarin was prescribed in 56.9% of cardioembolic strokes. The recurrence rate in ESUS patients was 4.4% per year, slightly higher than in cardioembolic strokes (3.5%) and significantly higher than in cryptogenic non-ESUS (1.2%) (P<0.0001). This is the first description of a cohort of ESUS patients in an Italian stroke unit. Patients with ESUS have a significantly higher risk of recurrence than in those with non-ESUS cryptogenic strokes, and slightly higher than in those with cardioembolic strokes. Results support the hypothesis of a more extensive diagnostic evaluation in cryptogenic strokes and the feasibility of such approach.
Performance evaluation of a developed rice-processing machine
Authors: Folami Adisa A. , Obioha Eberendu N. , Adewole Aderinlewo A. , Ibiyemi Kuye S.
Published: October 2016

Rice processing machines produced in developed countries are mostly unaffordable by rural farmers, hence there was need to develop cost effective/efficient machines produced from available local materials desirable in food industry that meets the need of the rural farmers. This study was to evaluate the performance of a developed rice dehusking/destoning machine at Federal University of Agriculture, Abeokuta, Nigeria. Minitab 16 was used for analysis of variance of two main factors [four paddy varieties Faro 35, Faro 44, Faro 55 and Ofada and five moisture content (MC) groups] to obtain its optimum operational parameters. Cleaning efficiency, coefficient of dehulling, coefficient of wholeness, dehulling efficiency, dehulling recovery and output capacity were optimum at 94.60%, 0.63, 0.85, 50.54%, 61.22% and 18.53 kg/h respectively. The effect of MC and test paddy variety on coefficient of wholeness and dehulling efficiency were significant while only MC effect was significant at P<0.05 on cleaning efficiency. Paddy varieties had effect on rice quality, long and slender grains had more breakage than shorter grains. After further work of improvement, its coefficient of dehulling, dehulling efficiency and dehulling recovery were 0.82, 65 and 75% respectively.
Association of Physical Inactivity, Weight, Smoking, and Prior Injury on Physical Performance in a Military Setting
Authors: Teyhen Deydre S. , Rhon Daniel I. , Butler Robert J. , Shaffer Scott W. , Goffar Stephen L. , McMillian Danny J. , Boyles Robert E. , Kiesel Kyle B. , Plisky Phillip J.
Published: October 2016

Context: Although inactivity, being overweight, smoking, and a history of injury are identified as risk factors for poor health and injury, few authors have examined their association on physical performance. Young adults may be more likely to adopt healthier lifestyles if they understand the effect of health behaviors on performance.

Objective: To determine the association of being overweight, smoking, inactivity, and a history of injury with physical performance.

Design: Cross-sectional study.

Setting: Military population.

Patients or Other Participants: Active-duty service members (N = 1466; 1380 men, 86 women; age = 24.7 ± 5.0 years; body mass index = 26.7 ± 3.4 kg/m2).

Main Outcome Measure(s): Participants performed 8 measures (the triple-crossover hop for distance, the 6-m timed-hop test, the Functional Movement Screen, the Lower Quarter Y-Balance Test, the Upper Quarter Y-Balance Test, and the 3-event Army Physical Fitness Test) for evaluation of endurance, strength, muscular endurance, power, agility, balance, and motor control. Participants were categorized based on the number of health risk factors present. Using an analysis of covariance, we assessed the relationship between risk factors and physical performance with age and sex as covariates.

Results: Compared with those who had no risk factors (27.9% of men, 34.9% of women), physical performance was worse in those who had 1, 2, or 3 to 4 risk factors present by 4.3%, 6.7%, and 10.3%, respectively. Decrements in performance for those with 3 to 4 risk factors ranged from 3.3% to 14.4%.

Conclusions: An unhealthy lifestyle habit or a history of injury was negatively associated with physical performance. Physical performance decrements were associated with the number of risk factors present. Understanding how risk factors contribute to decreased physical performance may enable clinicians to improve compliance with injury-prevention programs in occupational settings in which a young and relatively healthy workforce may be more concerned about performance than health.
A First-Order Assessment of Direct Aerosol Radiative Effect in the Southeastern U.S. Using over a Decade Long Multisatellite Data Record
Authors: Alston Erica J. , Sokolik Irina N.
Published: October 2016

Aerosols comprise a critical portion of the Earth's climate due to their radiative properties. More emphasis is now being placed upon understanding radiative effects of aerosols on a regional scale. The primary goal of this research is to estimate the aerosol direct radiative effect (DRE) and examine its dynamical nature in the Southeastern U.S. based on satellite data obtained from the moderate-resolution imaging spectroradiometer (MODIS) and multi-angle imaging spectroradiometer (MISR) instruments onboard the Terra satellite from 2000 to 2011. This 12-year analysis utilizes satellite measurements of aerosol optical depth (AOD), surface albedo, cloud fraction, and single-scattering albedo over the Southeastern U.S. as inputs to a first-order approximation of regional top of the atmosphere DRE. Results indicate that AOD is the primary driver of DRE estimates, with surface albedo and single-scattering albedo having some appreciable effects as well. During the cooler months, the minima (less negative) of DRE vary between -6 and -3 W/m2, and during the warmer months, there is more variation with DRE maxima varying between -24 and -12.6 W/m2 for MODIS and -22.5 and -11 W/m2 for MISR. Yet if we take an average of the monthly DRE over time (12 years), we estimate Δ F = -7.57 W/m2 for MODIS and Δ F = -5.72 W/m2 for MISR. Regional assessments of the DRE show that background levels of DRE are similar to the 12-year average of satellite-based DRE, with urbanized areas having increased levels of DRE compared to background conditions. Over the study period, DRE has a positive trend (becoming less negative), which implies that the region could lose this protective top of the atmosphere cooling with the advancement of climate change impacting the biogenic emissions of aerosols.