WorldWideScience

Sample records for machined surface quality

  1. Characterization of machining quality attributes based on spindle probe, coordinate measuring machine, and surface roughness data

    Directory of Open Access Journals (Sweden)

    Tzu-Liang Bill Tseng

    2014-04-01

    Full Text Available This study investigates the effects of machining parameters as they relate to the quality characteristics of machined features. Two most important quality characteristics are set as the dimensional accuracy and the surface roughness. Before any newly acquired machine tool is put to use for production, it is important to test the machine in a systematic way to find out how different parameter settings affect machining quality. The empirical verification was made by conducting a Design of Experiment (DOE with 3 levels and 3 factors on a state-of-the-art Cincinnati Hawk Arrow 750 Vertical Machining Center (VMC. Data analysis revealed that the significant factor was the Hardness of the material and the significant interaction effect was the Hardness + Feed for dimensional accuracy, while the significant factor was Speed for surface roughness. Since the equally important thing is the capability of the instruments from which the quality characteristics are being measured, a comparison was made between the VMC touch probe readings and the measurements from a Mitutoyo coordinate measuring machine (CMM on bore diameters. A machine mounted touch probe has gained a wide acceptance in recent years, as it is more suitable for the modern manufacturing environment. The data vindicated that the VMC touch probe has the capability that is suitable for the production environment. The test results can be incorporated in the process plan to help maintain the machining quality in the subsequent runs.

  2. A study of electrodischarge machining–pulse electrochemical machining combined machining for holes with high surface quality on superalloy

    Directory of Open Access Journals (Sweden)

    Ning Ma

    2015-11-01

    Full Text Available Noncircular holes on the surface of turbine rotor blades are usually machined by electrodischarge machining. A recast layer containing numerous micropores and microcracks is easily generated during the electrodischarge machining process due to the rapid heating and cooling effects, which restrict the wide applications of noncircular holes in aerospace and aircraft industries. Owing to the outstanding advantages of pulse electrochemical machining, electrodischarge machining–pulse electrochemical machining combined technique is provided to improve the overall quality of electrodischarge machining-drilled holes. The influence of pulse electrochemical machining processing parameters on the surface roughness and the influence of the electrodischarge machining–pulse electrochemical machining method on the surface quality and accuracy of holes have been studied experimentally. The results indicate that the pulse electrochemical machining processing time for complete removal of the recast layer decreases with the increase in the pulse electrochemical machining current. The low pulse electrochemical machining current results in uneven dissolution of the recast layer, while the higher pulse electrochemical machining current induces relatively homogeneous dissolution. The surface roughness is reduced from 4.277 to 0.299 µm, and the hole taper induced by top-down electrodischarge machining process was reduced from 1.04° to 0.17° after pulse electrochemical machining. On account of the advantages of electrodischarge machining and the pulse electrochemical machining, the electrodischarge machining–pulse electrochemical machining combined technique could be applied for machining noncircular holes with high shape accuracy and surface quality.

  3. SPARK MACHINING FOR STEEL SURFACES TO IMPROVE PAINT COATINGS QUALITY

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    Sergey Levchenko

    2015-12-01

    Full Text Available Spark machining of steel surfaces enhances the subsequent paint coatings adhesion and protective properties. These factors improvement was confirmed at the salt-spray chamber testing and by both adhesion to the surface and depth of corrosion penetration below the paint coating layer measurements.

  4. Surface quality analysis of die steels in powder-mixed electrical discharge machining using titan powder in fine machining

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    Banh Tien Long

    2016-06-01

    Full Text Available Improving the quality of surface molds after electrical discharge machining is still being considered by many researchers. Powder-mixed dielectric in electrical discharge machining showed that it is one of the processing methods with high efficiency. This article reports on the results of surface quality of mold steels after powder-mixed electrical discharge machining using titanium powder in fine machining. The process parameters such as electrode material, workpiece material, electrode polarity, pulse on-time, pulse off-time, current, and titanium powder concentration were considered in the research. These materials are most commonly used with die-sinking electrical discharge machining in the manufacture of molds and has been selected as the subject of research: workpiece materials were SKD61, SKT4, and SKD11 mold steels, and electrode materials were copper and graphite. Taguchi’s method is used to design experiments. The influence of the parameters on surface roughness was evaluated through the average value and ratio (S/N. Results showed that the parameters such as electrical current, electrode material, pulse on-time, electrode polarity, and interaction between the electrode materials with concentration powder mostly influence surface roughness and surface roughness at optimal parameters SRopt = 1.73 ± 0.39 µm. Analysis of the surface layer after powder-mixed electrical discharge machining using titanium powder in optimal conditions has shown that the white layer with more uniform thickness and increased hardness (≈861.0 HV, and amount and size of microscopic cracks, is reduced. This significantly leads to the increase in the quality of the surface layer.

  5. The use of frequency and wavelet analysis for monitoring surface quality of wood machining applications.

    Science.gov (United States)

    Lemaster, Richard L

    2010-01-01

    The research described in this study is part of a project to provide the technology and theory to quantify surface quality for a variety of wood and wood-based products. The ultimate goal is to provide a means of monitoring trends in surface quality, which can be used to discriminate between "good" products and "bad" products (the methods described in this research are not intended to provide "grading" of individual workpieces) as well as to provide information to the machine operator as to the source of poor-quality machined surfaces. This research investigates the use of both frequency domain analysis as well as the more advanced joint time frequency analysis (JTFA). The disadvantages of traditional frequency analysis as well as the potential of the JTFA are illustrated. Sample surface profiles from actual machining defects were analyzed using traditional frequency analysis. A surface with multiple machining defects was analyzed with both traditional frequency analysis and JTFA (harmonic wavelet). Although the analysis was empirical in nature, the results show that the harmonic wavelet transform is able to detect both stationary and non-stationary surface irregularities as well as pulses (localized defects).

  6. Surface quality of marble machined by abrasive water jet

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    Ramy Abdullah

    2016-12-01

    Full Text Available This paper presents a study conducted to examine the effect of cutting parameters, namely standoff distance, nozzle traverse speed (TS, abrasive flow rate (AFR, and material type on cutting performance for two types of marble workpieces, Carrara white and Indian green. Statistical analysis was undertaken to assess the influence of the cutting parameters on the process performances in terms of surface roughness, surface waviness, and Kerf taper ratio. The results showed that the TS and material type were the most significant factors that affected surface roughness and Kerf taper ratio. Also, although AFR was found to have significant effect on surface waviness, it had no noticeable influence on surface roughness nor Kerf taper ratio.

  7. Investigation and Evaluation on Influence of Machining (CNC Conditions on Surface Quality of Paulownia Wood

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    Mohammad Aghajani

    2012-01-01

    Full Text Available The aim of this study was to investigate the effective factors on surface quality of paulownia wood during machining by advanced computer numerical controled (CNC machine. For this aim paulownia logs were provided and were converted to proper sizes (2.5 x 10 x 15 cm and then air dried. The Variable of this study were cutting speed (8.37 and 15.07 m/s, feeding rate (6 and 12 m/min, cutting depth (1and 5 mm, cutting method (down and up-milling and cutting pattern (tangential and radial. Roughness of cut specimens edge were evaluated by profilometer method according to ISO 13565 standard. For evaluation of surface quality, average roughness (Ra, maximum roughness (R max, valley roughness (Rv and peak roughness (Rp were used. Degrees of effectiveness of the parameters were evaluated by fractional factorial design as completely random design at confidence level of 95%. The result showed that cutting speed, cutting method and feed rate are influencive factors on surface quality of machined specimens and their effects were significant. With increasing cutting speed and decreasing feeding rate the roughness decreased and surface quality improved. In up-milling cutting method, degree of roughness was higher and consequently surface quality was inferior. It is to be noted that cutting method in comparison to other factors had the high influence on surface quality. The rest variables did now have independent influence on surface quality at 95% Confidence level. This study for achieving the optimum surface quality recommends that cutting speed of 15.07 m/s, feeding rate of 6 m/min, cutting method of down-milling and cutting depth of 1 mm for tangential cross section.

  8. The influence of mixing water and abrasives on the quality of machined surface

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    A. Stoić

    2014-04-01

    Full Text Available This paper shows the impact of mixing water and abrasives in water jet cutting process on the quality of the machined surface. The tests were done with polymer material SIPAS, where the influence of cutting parameters was researched (cutting pressure, cutting feed and abrasive mass flow. The surface roughness was measured on several zones, regarding the depth of materials, because the roughness is increased with the material thickness.

  9. Adaptive tool servo diamond turning for enhancing machining efficiency and surface quality of freeform optics.

    Science.gov (United States)

    Zhu, Zhiwei; To, Suet

    2015-08-10

    Fast tool servo/ slow tool servo (FTS/STS) diamond turning is a very promising technique for the generation of freeform optics. However, the currently adopted constant scheme for azimuth sampling and side-feeding motion possesses no adaptation to surface shape variation, leading to the non-uniform surface quality and low machining efficiency. To overcome this defect, this paper reports on a novel adaptive tool servo (ATS) diamond turning technique which is essentially based on the novel two-degree-of-freedom (2-DOF) FTS/STS. In the ATS, the sampling interval and the side-feeding motion are actively controlled at any cutting point to adapt the machining process to shape variation of the desired surface, making both the sampling induced interpolation error and the side-feeding induced residual tool mark be within the desired tolerances. Characteristic of the required cutting motion suggests that besides the conventional z-axis servo motion, another servo motion along the x-axis synthesizing by the c-axis is mandatory for implementing the ATS. Comparative studies of surface generation of typical micro-structured surfaces in FTS/STS and ATS are thoroughly conducted both theoretically and experimentally. The result demonstrates that the ATS outperforms the FTS/STS with improved surface quality while simultaneously enhanced machining efficiency.

  10. Effects of the technolology of machining on the surface quality of selected wood

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    Michal Svatoš

    2011-01-01

    Full Text Available The paper deals with the dependence of using basic types of machining technologies on the surface quality of most common wood. In wood-processing industry, cutting by circular-saw blades and milling are the most often used technology to machining wood materials. The quality and accuracy of the machining are derived from the machine construction, shape and the amount of saw teeth, kind of wood species, feed per tooth and the size of the tool. Research was carried out on an experimental milling stand at setting various feed speeds and the spindle rpm, on an experimental cutting stand at using three types of circular-saw blades in the field of optimum and resonance rpm. Evaluation of the surface quality was carried out on a top multisensor apparatus Taylor Hobson-Talysurf CLI 1000 using a contactless method by a confocal sensor. Software equipment of a powerful computer was provided by the Talymap platinum program. Tree species were evaluated generally from the aspect of roughness and waviness altogether. An expert evaluation is carried out from two aspects. The first aspect is selection of the best technology for actual wood and the second aspect is selection of the best species for the actual technology. Particular relationships between wood and technology are evidently best described by graphs.

  11. A study of electrodischarge machining–pulse electrochemical machining combined machining for holes with high surface quality on superalloy

    OpenAIRE

    Ning Ma; Xiaolong Yang; Mingqian Gao; Jinlong Song; Ganlin Liu; Wenji Xu

    2015-01-01

    Noncircular holes on the surface of turbine rotor blades are usually machined by electrodischarge machining. A recast layer containing numerous micropores and microcracks is easily generated during the electrodischarge machining process due to the rapid heating and cooling effects, which restrict the wide applications of noncircular holes in aerospace and aircraft industries. Owing to the outstanding advantages of pulse electrochemical machining, electrodischarge machining–pulse electrochemic...

  12. Bi-objective robust optimization of machined surface quality and productivity under vibrations limitation

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    Sahali M.A.

    2015-01-01

    Full Text Available In this contribution, a bi-objective robust optimization of cutting parameters, with the taking into account uncertainties inherent in the tool wear and the tool deflection for a turning operation is presented. In a first step, we proceed to the construction of substitution models that connect the cutting parameters to the variables of interest based on design of experiments. Our two objectives are the best machined surface quality and the maximum productivity under consideration of limitations related to the vibrations and the range of the three cutting parameters. Then, using the developed genetic algorithm that based on a robust evaluation mechanism of chromosomes by Monte-Carlo simulations, the influence and interest of the uncertainties integration in the machining optimization is demonstrated. After comparing the classical and robust Pareto fronts, A surface quality less efficient but robust can be obtained with the consideration of uncontrollable factors or uncertainties unlike that provides the deterministic and classical optimization for the same values of productivity.

  13. EVALUATION OF MACHINE TOOL QUALITY

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    Ivan Kuric

    2011-12-01

    Full Text Available Paper deals with aspects of quality and accuracy of machine tools. As the accuracy of machine tools has key factor for product quality, it is important to know the methods for evaluation of quality and accuracy of machine tools. Several aspects of diagnostics of machine tools are described, such as aspects of reliability.

  14. EXPERIMENTAL IMPACT ASSESSMENT OF PARAMETERS PERTAINING TO BLANK TWO-DIMENSIONAL CIRCULAR MOTION ON INTENSITY OF ITS CUTTING AND QUALITY OF MACHINED SURFACE

    National Research Council Canada - National Science Library

    M. G. Kiselev; A. V. Drozdov; S. G. Monich; D. A. Yamnaya

    2014-01-01

    The purpose of the paper is to make an experimental impact assessment of parameters pertaining to blank two-dimensional circular blank motion on intensity of its cutting and quality of the machined surfaces...

  15. Experimental investigation of surface quality in ultrasonic machining of WC-Co composites through Taguchi method

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    B. S. Pabla

    2016-08-01

    Full Text Available In manufacturing industries, the demand of WC-Co composite is flourishing because of the distinctive characteristics it offers such as: toughness (with hardness, good dimensional stability, higher mechanical strength etc. However, the difficulties in its machining restrict the application and competitiveness of this material. The current article has been targeted at evaluation of the effect of process conditions (varying power rating, cobalt content, tool material, part thickness, tool geometry, and size of abrasive particle on surface roughness in ultrasonic drilling of WC-Co composite. Results showed that abrasive grit size is most influential factor. From the microstructure analysis, the mode of material deformation has been observed and the parameters, i.e. work material properties, grit size, and power rating was revealed as the most crucial for the deformation mode.

  16. Machining of Complex Sculptured Surfaces

    CERN Document Server

    2012-01-01

    The machining of complex sculptured surfaces is a global technological topic in modern manufacturing with relevance in both industrialized and emerging in countries particularly within the moulds and dies sector whose applications include highly technological industries such as the automotive and aircraft industry. Machining of Complex Sculptured Surfaces considers new approaches to the manufacture of moulds and dies within these industries. The traditional technology employed in the manufacture of moulds and dies combined conventional milling and electro-discharge machining (EDM) but this has been replaced with  high-speed milling (HSM) which has been applied in roughing, semi-finishing and finishing of moulds and dies with great success. Machining of Complex Sculptured Surfaces provides recent information on machining of complex sculptured surfaces including modern CAM systems and process planning for three and five axis machining as well as explanations of the advantages of HSM over traditional methods ra...

  17. EVALUATION OF MACHINABILITY OF DUCTILE IRONS ALLOYED WITH Ni AND Cu IN TERMS OF CUTTING FORCES AND SURFACE QUALITY

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    Yücel AŞKUN

    2003-02-01

    Full Text Available Due to the enhanced strength, ductility and thoughness of Ductile Iron (DI when compared to the other types cast iron, its machinability is relatively poor. When a steel part is replaced with ductile iron, however, better machinability is considered to be the most important gain. This study presents the results of machining tests of ductile irons alloyed with Ni and Cu at various contents to determine the effect of their microstructure and mechanical properties on cutting forces and surface roughness. Six different specimen groups of ductile iron alloyed with various amounts of nickel and copper were subjected to machining tests and their machinabilities were investigated based on cutting forces and surface roughness criteria. The results were evaluated according to microstructure and mechanical properties of specimens determined before. In terms of both criterion, the best result obtained was specimen added 0.7 % Ni and 0.7 % Cu. When the specimens were evaluated according to their mechanical properties, the specimens alloyed 1 % Ni and 0.65 % Cu seemed promising.

  18. Influence of Chatter of VMC Arising During End Milling Operation and Cutting Conditions on Quality of Machined Surface

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    A.K.M.N. Amin, M.A. Rizal, and M. Razman

    2012-08-01

    Full Text Available Machine tool chatter is a dynamic instability of the cutting process. Chatter results in poor part surface finish, damaged cutting tool, and an irritating and unacceptable noise. Exten¬sive research has been undertaken to study the mechanisms of chatter formation. Efforts have been also made to prevent the occurrence of chatter vibration. Even though some progress have been made, fundamental studies on the mechanics of metal cutting are necessary to achieve chatter free operation of CNC machine tools to maintain their smooth operating cycle. The same is also true for Vertical Machining Centres (VMC, which operate at high cutting speeds and are capable of offering high metal removal rates. The present work deals with the effect of work materials, cutting conditions and diameter of end mill cutters on the frequency-amplitude characteristics of chatter and on machined surface roughness. Vibration data were recorded using an experimental rig consisting of KISTLER 3-component dynamometer model 9257B, amplifier, scope meters and a PC.  Three different types of vibrations were observed. The first type was a low frequency vibration, associated with the interrupted nature of end mill operation. The second type of vibration was associated with the instability of the chip formation process and the third type was due to chatter. The frequency of the last type remained practically unchanged over a wide range of cutting speed.  It was further observed that chip-tool contact processes had considerable effect on the roughness of the machined surface.Key Words: Chatter, Cutting Conditions, Stable Cutting, Surface Roughness.

  19. EXPERIMENTAL IMPACT ASSESSMENT OF PARAMETERS PERTAINING TO BLANK TWO-DIMENSIONAL CIRCULAR MOTION ON INTENSITY OF ITS CUTTING AND QUALITY OF MACHINED SURFACE

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    M. G. Kiselev

    2014-01-01

    Full Text Available The purpose of the paper is to make an experimental impact assessment of parameters pertaining to blank two-dimensional circular blank motion on intensity of its cutting and quality of the machined surfaces. Experimental data have been obtained that reveal efficiency in application of blank circular motion and improvement of its output cutting indices.A methodology has been developed for execution of comparative experimental investigations on cutting glass, nephrite and jasper specimens as under conventional conditions required for the operation so while transferring induced oscillations to boom suspension assembly that ensure specimen.The proposed methodology makes it possible to assess quantitatively intensity of specimen cutting and quality of its machined surface. The paper has shown that a positive impact of the specimen circular motion on quality improvement of its cross-cut surface is related to peculiar kinematics features pertaining to relative motion of disc side surface with cross-cut portions of the specimen surface. It has been shown that the intensifying impact of the specimen circular motion on the cutting process is primarily related to the changes in dynamic conditions of its interaction with the cutting edge of the disc. In contrast to conventional cutting when the process is going on under static pressure of contacting surfaces there is their periodical impact-frictional interaction due to transfer of circular motion to the specimen along elliptical trajectory. In this case the rate of the positive impact of the specimen circular motion on its cross-cut surface becomes higher while increasing vertical velocity component that concerns its sliding relative to disc side surface that is ensured by increasing oscillation frequency which is transferred to the boom suspension assembly. Moreover, the rate of positive impact of the specimen circulatory motion on the quality of its cross-cut surface becomes higher while increasing

  20. Investigation of Surfaces after Non Conventional Machining

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    Micietova, Anna; Neslusan, Miroslav; Cillikova, Maria

    2016-12-01

    This paper deals with analysis of surface integrity of steel after electro discharge machining (EDM), water jet machining, (WJM) laser beam machining (LBM) and plasma beam machining (PBM). The paper discusses surface integrity expressed in surface roughness, sample precision expressed in perpendicularity deviation as well as stress state. This study also demonstrates influence of the various non-conventional methods on structure transformations and reports about sensitivity of the different non-conventional methods of machining with regard to variable thickness of machined samples.

  1. EXPERIMENTAL EVALUATION OF WEDM MACHINED SURFACE WAVINESS

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    Katerina Mouralova

    2016-10-01

    Full Text Available Wire Electrical Discharge Machining (WEDM an unconventional machining technology which has become indispensable in many industries. The typical morphology of a surface machined using the electrical discharge technology is characterized with a large number of craters caused by electro-spark discharges produced during the machining process. The study deals with an evaluation of the machine parameter setting on the profile parameters of surface waviness on samples made of two metal materials Al 99.5 and Ti-6Al-4V. Attention was also paid to an evaluation of the surface morphology using 3D colour filtered and non-filtered images.

  2. Surface magnetic domains dynamic in machined steel

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    Blažek D.

    2014-07-01

    Full Text Available This contribution deals with an observation of the magnetic dynamic of different types of the machined surface of bearing steel. The Bakhausen noise (BN measurements are presented here as commonly introduced in industry for quality control due to the extremely sensitivity of the magnetic domains wall dynamics to the microstructure of material. The results of magneto-optical measurements are presented with the goal to explain the observed BN anisotropy. It is shown that BN anisotropy is associated with uniaxal magnetic anisotropy introduced by hard milling which causes the principally different magnetic reversals processes in orthogonal directions.

  3. Efficient machining of ultra precise steel moulds with freeform surfaces

    Science.gov (United States)

    Bulla, B.; Robertson, D. J.; Dambon, O.; Klocke, F.

    2013-09-01

    Ultra precision diamond turning of hardened steel to produce optical quality surfaces can be realized by applying an ultrasonic assisted process. With this technology optical moulds used typically for injection moulding can be machined directly from steel without the requirement to overcoat the mould with a diamond machinable material such as Nickel Phosphor. This has both the advantage of increasing the mould tool lifetime and also reducing manufacture costs by dispensing with the relatively expensive plating process. This publication will present results we have obtained for generating free form moulds in hardened steel by means of ultrasonic assisted diamond turning with a vibration frequency of 80 kHz. To provide a baseline with which to characterize the system performance we perform plane cutting experiments on different steel alloys with different compositions. The baseline machining results provides us information on the surface roughness and on tool wear caused during machining and we relate these to material composition. Moving on to freeform surfaces, we will present a theoretical background to define the machine program parameters for generating free forms by applying slow slide servo machining techniques. A solution for optimal part generation is introduced which forms the basis for the freeform machining experiments. The entire process chain, from the raw material through to ultra precision machining is presented, with emphasis on maintaining surface alignment when moving a component from CNC pre-machining to final machining using ultrasonic assisted diamond turning. The free form moulds are qualified on the basis of the surface roughness measurements and a form error map comparing the machined surface with the originally defined surface. These experiments demonstrate the feasibility of efficient free form machining applying ultrasonic assisted diamond turning of hardened steel.

  4. SURFACE QUALITY INSPECTION OF CERAMIC TILES BY MACHINE VISION%陶瓷砖表面质量视觉检测系统研究

    Institute of Scientific and Technical Information of China (English)

    李庆利; 郭彩玲; 张向红

    2011-01-01

    重点介绍了机器视觉技术在陶瓷砖表面质量检测中的应用.系统采用面阵摄象机作为测量工具,应用方向算子进行对目标边缘的定位和跟踪,以便获得完整、精确、封闭的目标边缘.实现了对陶瓷砖的边直度、直角度、缺边和缺角等项目的非接触检测.%In this paper, an on-line machine vision system for surface quality inspection of ceramic tiles is introduced, which grabs the images scanned by area-array cameras. The image processing algorithm which uses direction masks is used to locate the edge points exactly. The surface quality of ceramic tiles is measured by the real-time, high precision and non-contact method, which can detect straightness of sides, deviation from rectangularity, rough edge, chip and so on.

  5. STUDY ON SURFACE QUALITY OF CERAMIC TILES BY MACHINE VISION%陶瓷砖表面质量视觉检测系统研究

    Institute of Scientific and Technical Information of China (English)

    李庆利; 郭彩玲; 张向红

    2011-01-01

    In this paper an on-line machine vision system for surface quality of ceramic tiles is introduced, which grabs the images scanned by area-array camera.The image processing algorithm which uses direction masks is used to locate the edge points exactly.The surface quality of ceramic tiles is measured with the real-time, high precision and non-contact method, which includes straightness of sides,deviation from rectangularity, rough edge,chip and so on.%重点介绍了机器视觉技术在陶瓷砖表面质量检测中的应用.系统采用面阵摄像机作为测量工具,应用方向算子进行对目标边缘的定位和跟踪,以便获得完整、精确、封闭的目标边缘.实现了对陶瓷砖的边直度、直角度、缺边和缺角等项目的非接触检测.

  6. Switching surface chemistry with supramolecular machines.

    Energy Technology Data Exchange (ETDEWEB)

    Dunbar, Timothy D.; Kelly, Michael James; Jeppesen, Jan O. (University of California, Los Angeles, CA); Bunker, Bruce Conrad; Matzke, Carolyn M.; Stoddart, J. Fraser; Huber, Dale L.; Kushmerick, James G.; Flood, Amar H. (University of California, Los Angeles, CA); Perkins, Julie (University of California, Los Angeles, CA); Cao, Jianguo (University of California, Los Angeles, CA)

    2005-07-01

    Tethered supramolecular machines represent a new class of active self-assembled monolayers in which molecular configurations can be reversibly programmed using electrochemical stimuli. We are using these machines to address the chemistry of substrate surfaces for integrated microfluidic systems. Interactions between the tethered tetracationic cyclophane host cyclobis(paraquat-p-phenylene) and dissolved {pi}-electron-rich guest molecules, such as tetrathiafulvalene, have been reversibly switched by oxidative electrochemistry. The results demonstrate that surface-bound supramolecular machines can be programmed to adsorb or release appropriately designed solution species for manipulating surface chemistry.

  7. Engineered Surface Properties of Porous Tungsten from Cryogenic Machining

    Science.gov (United States)

    Schoop, Julius Malte

    Porous tungsten is used to manufacture dispenser cathodes due to it refractory properties. Surface porosity is critical to functional performance of dispenser cathodes because it allows for an impregnated ceramic compound to migrate to the emitting surface, lowering its work function. Likewise, surface roughness is important because it is necessary to ensure uniform wetting of the molten impregnate during high temperature service. Current industry practice to achieve surface roughness and surface porosity requirements involves the use of a plastic infiltrant during machining. After machining, the infiltrant is baked and the cathode pellet is impregnated. In this context, cryogenic machining is investigated as a substitutionary process for the current plastic infiltration process. Along with significant reductions in cycle time and resource use, surface quality of cryogenically machined un-infiltrated (as-sintered) porous tungsten has been shown to significantly outperform dry machining. The present study is focused on examining the relationship between machining parameters and cooling condition on the as-machined surface integrity of porous tungsten. The effects of cryogenic pre-cooling, rake angle, cutting speed, depth of cut and feed are all taken into consideration with respect to machining-induced surface morphology. Cermet and Polycrystalline diamond (PCD) cutting tools are used to develop high performance cryogenic machining of porous tungsten. Dry and pre-heated machining were investigated as a means to allow for ductile mode machining, yet severe tool-wear and undesirable smearing limited the feasibility of these approaches. By using modified PCD cutting tools, high speed machining of porous tungsten at cutting speeds up to 400 m/min is achieved for the first time. Beyond a critical speed, brittle fracture and built-up edge are eliminated as the result of a brittle to ductile transition. A model of critical chip thickness ( hc ) effects based on cutting

  8. Supporting visual quality assessment with machine learning

    NARCIS (Netherlands)

    Gastaldo, P.; Zunino, R.; Redi, J.

    2013-01-01

    Objective metrics for visual quality assessment often base their reliability on the explicit modeling of the highly non-linear behavior of human perception; as a result, they may be complex and computationally expensive. Conversely, machine learning (ML) paradigms allow to tackle the quality

  9. Fabrication of microfluidic devices: improvement of surface quality of CO2 laser machined poly(methylmethacrylate) polymer

    Science.gov (United States)

    Mohammed, Mazher I.; Nazrul Hisham Zainal Alam, Muhd; Kouzani, Abbas; Gibson, Ian

    2017-01-01

    Laser engraving has considerable potential for the rapid and cost effective manufacturing of polymeric microfluidic devices. However, fabricated devices are hindered by relatively large surface roughness in the engraved areas, which can perturb smooth fluidic flow and can damage sensitive biological components. This effect is exacerbated when engraving at depths beyond the laser focal range, limiting the production of large aspect ratio devices such as microbioreactors. This work aims to overcome such manufacturing limitations and to realise more reproducible and defect free microfluidic channels and structures. We present a strategy of multiple engraving passes alongside solvent polymer reflow for shallow depth (500 µm) features. To examine the proposed methodologies, capillary action and bioreactor microfluidic devices were fabricated and evaluated. Results indicate that the multiple engraving technique could reproduce engraved microfluidic channels to depths between 50-470 µm, both rapidly (6-8 min) and with low average surface roughness (1.5-2.5 µm). The layer cutting approach was effective at manufacturing microfluidic devices with depths  <500 µm, rapidly (<1 min) and with low surface roughness. Ultimately, the proposed methodology is highly beneficial for the rapid development of polymer-based microfluidic devices.

  10. Self-Calibrating Surface Measuring Machine

    Science.gov (United States)

    Greenleaf, Allen H.

    1983-04-01

    A new kind of surface-measuring machine has been developed under government contract at Itek Optical Systems, a Division of Itek Corporation, to assist in the fabrication of large, highly aspheric optical elements. The machine uses four steerable distance-measuring interferometers at the corners of a tetrahedron to measure the positions of a retroreflective target placed at various locations against the surface being measured. Using four interferometers gives redundant information so that, from a set of measurement data, the dimensions of the machine as well as the coordinates of the measurement points can be determined. The machine is, therefore, self-calibrating and does not require a structure made to high accuracy. A wood-structured prototype of this machine was made whose key components are a simple form of air bearing steering mirror, a wide-angle cat's eye retroreflector used as the movable target, and tracking sensors and servos to provide automatic tracking of the cat's eye by the four laser beams. The data are taken and analyzed by computer. The output is given in terms of error relative to an equation of the desired surface. In tests of this machine, measurements of a 0.7 m diameter mirror blank have been made with an accuracy on the order of 0.2µm rms.

  11. Optical servoing for industrial surface machining

    Science.gov (United States)

    Koller, Norbert; Ofner, Ronald; O'Leary, Paul; Fauster, Ewald

    2006-02-01

    The surface machining of cracks is a key issue to ensure the quality of steel rods and billets. The aim is to grind these defects out of the material. This paper presents a real-time optical servo-system, consisting of three image processing systems and an industrial robot, which fully automate this process. A high resolution color progressive scan camera, placed at a suitable position above the roller conveyor, observes the material and detects color markings indicating the presence of a crack. This camera system controls the roller conveyor transporting the material until a marked crack is detected. Diffuse light sources provide homogeneous lighting to ensure reliable detection of the markings. A demosaicing algorithm, RGB to HSL color modeling and thresholding with statistical morphology are used to identify the marked areas. On detecting a crack the material is automatically positioned within the working area of an industrial robot. A collineation is used to generate metric two-dimensional coordinates corresponding to the bounding rectangle of the detected error. At this point two plane-of-light scanners are used to acquire a cross section of the material to the left and the right of the robot's working area. From this, a three-dimensional model for the rod or billet surface is calculated and the two-dimensional coordinates of the color marking are projected onto this surface to generate a patch. The coordinates of this patch are sent to the 6R industrial robot, which then grinds out the defect. A new concept has been implemented which enables the calibration of the three image processing systems and the industrial robot so as to have one common coordinate system. Operational results have shown the full functionality of the system concept in the harsh environment of a steel production facility.

  12. Development of Virtual Simulation System for Remote Collaborative Surface Machining

    Institute of Scientific and Technical Information of China (English)

    R.S.Lee; Y.S.Lin; Y.C.Kao; C. H. She

    2006-01-01

    Most researches about virtual machine tool are emphasized on simulations of machine motion and machining process for single machine. In this paper, a virtual simulation system for remote collaborative surface machining is developed. The motion command of machine tool is generated by an interpolator, which can derive synchronized motion commands according to feedrate. Thus, the system can estimate the machining time. For universal assembly of five-axis virtual machine tool, it is based on the D-H notation representation and machining constraints consideration. The remote collaborative virtual manufacturing system based on the CORBA technology is proposed in this paper. It demonstrated that the developed virtual machine tool can be used to verify and simulate the machining process for the collaboration of the surface design and manufacturing team.

  13. Visual quality assessment by machine learning

    CERN Document Server

    Xu, Long; Kuo, C -C Jay

    2015-01-01

    The book encompasses the state-of-the-art visual quality assessment (VQA) and learning based visual quality assessment (LB-VQA) by providing a comprehensive overview of the existing relevant methods. It delivers the readers the basic knowledge, systematic overview and new development of VQA. It also encompasses the preliminary knowledge of Machine Learning (ML) to VQA tasks and newly developed ML techniques for the purpose. Hence, firstly, it is particularly helpful to the beginner-readers (including research students) to enter into VQA field in general and LB-VQA one in particular. Secondly, new development in VQA and LB-VQA particularly are detailed in this book, which will give peer researchers and engineers new insights in VQA.

  14. Sub-surface and surface analysis of high speed machined Ti-6Al-4V alloy

    Energy Technology Data Exchange (ETDEWEB)

    Velasquez, J.D. Puerta [Laboratoire d' Etude des Textures et Applications aux Materiaux (LETAM), CNRS FRE 3143, Ecole Nationale d' Ingenieurs de Metz (ENIM), F-57012 Metz Cedex 01 (France); Tidu, A., E-mail: tidu@enim.fr [Laboratoire d' Etude des Textures et Applications aux Materiaux (LETAM), CNRS FRE 3143, Ecole Nationale d' Ingenieurs de Metz (ENIM), F-57012 Metz Cedex 01 (France); Bolle, B. [Laboratoire d' Etude des Textures et Applications aux Materiaux (LETAM), CNRS FRE 3143, Ecole Nationale d' Ingenieurs de Metz (ENIM), F-57012 Metz Cedex 01 (France); Chevrier, P. [Laboratoire de Mecanique Biomecanique, Polymere Structures (LaBPS), EA 4632 Ecole Nationale d' Ingenieurs de Metz (ENIM), F-57012 Metz Cedex 01 (France); Fundenberger, J.-J. [Laboratoire d' Etude des Textures et Applications aux Materiaux (LETAM), CNRS FRE 3143, Universite Paul Verlaine de Metz (UPVM), F-57012 Metz Cedex 01 (France)

    2010-04-25

    To understand the effects of cutting the surface integrity is an important goal to control the quality of a work piece. The current paper summarizes an extensive experimental study of the surface integrity and the sub-surface microstructure during high speed machining in orthogonal cutting condition. This study includes measurements of residual stresses and crystallographic texture in addition to electron microscopy observations. Our observations and conclusions are primarily focused on the effect of cutting speed considering a set of constant machining parameters on the microstructure evolution of the sub-surface of the material. The results allow a better understanding of the cutting process in high speed machining of titanium alloy Ti-6Al-4V.

  15. Characteristics of machined surface controlled by cutting tools and conditions in machining of brittle material

    Institute of Scientific and Technical Information of China (English)

    Yong-Woo KIM; Soo-Chang CHOI; Jeung-Woo PARK; Deug-Woo LEE

    2009-01-01

    One of the ultra-precision machining methods was adapted for brittle material as well as soft material by using multi-arrayed diamond tips and high speed spindle. Conventional machining method is too hard to control surface roughness and surface texture against brittle material because the particles of grinding tools are irregular size and material can be fragile. Therefore, we were able to design tool paths and machine controlled pattern on surface by multi-arrayed diamond tips with uniform size made in MEMS fabrication and high speed spindle, and the maximum speed was about 3×105 r/min. We defined several parameters that can affect the machining surface. Those were multi-array of diamond tips (n×n), speed of air spindle and feeding rate. The surface roughness and surface texture can be controlled by those parameters for micro machining.

  16. Surface grain coarsening and surface softening during machining of ultra-fine grained titanium

    Directory of Open Access Journals (Sweden)

    Symonova A.A.

    2012-01-01

    Full Text Available Experiments are run to show that different machining conditions applied to ultra-fine grained pure titanium lead to different levels of grain coarsening and softening near the machined surface. Under “hard” machining conditions the upper 40 microns of the machined surface are altered with a decreased microhardness. The experimental results are reasonably reproduced by model calculations. Expanding the parameter field of the model calculations, the surface coarsening diagram and the surface softening diagram due to machining are presented, showing the region of technological parameters, under which neither grain coarsening nor softening takes place along the machined surface.

  17. Surface mining machines problems of maintenance and modernization

    CERN Document Server

    Rusiński, Eugeniusz; Moczko, Przemysław; Pietrusiak, Damian

    2017-01-01

    This unique volume imparts practical information on the operation, maintenance, and modernization of heavy performance machines such as lignite mine machines, bucket wheel excavators, and spreaders. Problems of large scale machines (mega machines) are highly specific and not well recognized in the common mechanical engineering environment. Prof. Rusiński and his co-authors identify solutions that increase the durability of these machines as well as discuss methods of failure analysis and technical condition assessment procedures. "Surface Mining Machines: Problems in Maintenance and Modernization" stands as a much-needed guidebook for engineers facing the particular challenges of heavy performance machines and offers a distinct and interesting demonstration of scale-up issues for researchers and scientists from across the fields of machine design and mechanical engineering.

  18. Learning surface molecular structures via machine vision

    Science.gov (United States)

    Ziatdinov, Maxim; Maksov, Artem; Kalinin, Sergei V.

    2017-08-01

    Recent advances in high resolution scanning transmission electron and scanning probe microscopies have allowed researchers to perform measurements of materials structural parameters and functional properties in real space with a picometre precision. In many technologically relevant atomic and/or molecular systems, however, the information of interest is distributed spatially in a non-uniform manner and may have a complex multi-dimensional nature. One of the critical issues, therefore, lies in being able to accurately identify (`read out') all the individual building blocks in different atomic/molecular architectures, as well as more complex patterns that these blocks may form, on a scale of hundreds and thousands of individual atomic/molecular units. Here we employ machine vision to read and recognize complex molecular assemblies on surfaces. Specifically, we combine Markov random field model and convolutional neural networks to classify structural and rotational states of all individual building blocks in molecular assembly on the metallic surface visualized in high-resolution scanning tunneling microscopy measurements. We show how the obtained full decoding of the system allows us to directly construct a pair density function—a centerpiece in analysis of disorder-property relationship paradigm—as well as to analyze spatial correlations between multiple order parameters at the nanoscale, and elucidate reaction pathway involving molecular conformation changes. The method represents a significant shift in our way of analyzing atomic and/or molecular resolved microscopic images and can be applied to variety of other microscopic measurements of structural, electronic, and magnetic orders in different condensed matter systems.

  19. Laser surface texturing of tool steel: textured surfaces quality evaluation

    Science.gov (United States)

    Šugár, Peter; Šugárová, Jana; Frnčík, Martin

    2016-05-01

    In this experimental investigation the laser surface texturing of tool steel of type 90MnCrV8 has been conducted. The 5-axis highly dynamic laser precision machining centre Lasertec 80 Shape equipped with the nano-second pulsed ytterbium fibre laser and CNC system Siemens 840 D was used. The planar and spherical surfaces first prepared by turning have been textured. The regular array of spherical and ellipsoidal dimples with a different dimensions and different surface density has been created. Laser surface texturing has been realized under different combinations of process parameters: pulse frequency, pulse energy and laser beam scanning speed. The morphological characterization of ablated surfaces has been performed using scanning electron microscopy (SEM) technique. The results show limited possibility of ns pulse fibre laser application to generate different surface structures for tribological modification of metallic materials. These structures were obtained by varying the processing conditions between surface ablation, to surface remelting. In all cases the areas of molten material and re-cast layers were observed on the bottom and walls of the dimples. Beside the influence of laser beam parameters on the machined surface quality during laser machining of regular hemispherical and elipsoidal dimple texture on parabolic and hemispherical surfaces has been studied.

  20. Compensation strategy for machining optical freeform surfaces by the combined on- and off-machine measurement.

    Science.gov (United States)

    Zhang, Xiaodong; Zeng, Zhen; Liu, Xianlei; Fang, Fengzhou

    2015-09-21

    Freeform surface is promising to be the next generation optics, however it needs high form accuracy for excellent performance. The closed-loop of fabrication-measurement-compensation is necessary for the improvement of the form accuracy. It is difficult to do an off-machine measurement during the freeform machining because the remounting inaccuracy can result in significant form deviations. On the other side, on-machine measurement may hides the systematic errors of the machine because the measuring device is placed in situ on the machine. This study proposes a new compensation strategy based on the combination of on-machine and off-machine measurement. The freeform surface is measured in off-machine mode with nanometric accuracy, and the on-machine probe achieves accurate relative position between the workpiece and machine after remounting. The compensation cutting path is generated according to the calculated relative position and shape errors to avoid employing extra manual adjustment or highly accurate reference-feature fixture. Experimental results verified the effectiveness of the proposed method.

  1. ANALYSIS OF PARAMETERS AFFECTING THE QUALITY OF A CUTTING MACHINE

    Directory of Open Access Journals (Sweden)

    Iveta Onderová

    2014-02-01

    Full Text Available The quality of cutting machines is affected by several factors that can be directly or indirectly influenced by manufacturers, technicians and users of machine tools. The most critical qualitative evaluation parameters of machine tools include accuracy and stability. Investigations of accuracy and repeatable positioning accuracy were essential for the research presented in this paper. The aim was to develop and experimentally verify the design of a methodology for cutting centers aimed at achieving the desired working precision. Before working on the topic described here, it was necessary to make several scientific analyses, which are summarized in this paper. We can build on the initial working hypothesis that by improving the technological parameters (e.g. by increasing the working speed of the machine, or by improving the precision of the positioning the quality of the cutting machine will also be improved. For the purposes of our study, several investigated parameters were set affecting positioning accuracy, such as rigidity, positioning speed, etc. First, the stiffness of the portal structure of the cutting machine was analyzed. FEM analysis was used to investigate several alternative structures of the cutting machine, and also an innovative solution for beam mounting. The second step was to integrate two types of drives into the design of the cutting machine. The first drive is a classic rack and pinion drive for cutting machines. To increase (improve the working speed of the machine, linear motors were designed as an alternative drive. The portal of the cutting machine was designed for a working speed of 260mmin−1 and acceleration of 25 m. s−2. The third step was based on the results of the analysis. In collaboration with Microstep, an experimental cutting machine in a portal version was produced using linear synchronous motors driving the portal on both sides, and with direct linear metering of its position. In the fourth step, an

  2. Non-machined Surface Protection Process of Electrochemical Machining Based on Repaired Turbine Blade

    Directory of Open Access Journals (Sweden)

    LIU Wei-dong

    2016-11-01

    Full Text Available In order to improve the efficiency of turbine blade repairing, protection processes of non-machined surface in Electrochemical Machining (ECM based on blade repairing were studied. Mathematical model of electric field was developed to obtain current density distribution on anode surface, and to study the repairing principle and consequently analyze the defects forming mechanism by conventional electrolytic repair process. Sacrificial layer process was proposed to protect the non-machined surface in this work and an experimental system was developed to shape overlay welded TC4 blades. The results show that directly shaping process and insulated layer process produce stray dissolution and "stair" defects respectively,while sacrificial layer process achieves acceptable machining performance. With shaping time of 60s, the efficiency is improved; shaped blades have higher precision and surface roughness is Ra≤0.6μm, and with higher repeatability, the design requirements can be met.

  3. Application of atmospheric pressure plasma polishing method in machining of silicon ultra-smooth surfaces

    Institute of Scientific and Technical Information of China (English)

    Jufan ZHANG; Bo WANG; Shen DONG

    2008-01-01

    The modern optics industry demands rigorous surface quality with minimum defects, which presents challenges to optics machining technologies. There are always certain defects on the final surfaces of the compo-nents formed in conventional contacting machining proc-esses, such as micro-cracks, lattice disturbances, etc. It is especially serious for hard-brittle functional materials, such as crystals, glass and ceramics because of their special characteristics. To solve these problems, the atmospheric pressure plasma polishing (APPP) method is developed. It utilizes chemical reactions between reactive plasma and surface atoms to perform atom-scale material removal. Since the machining process is chemical in nature, APPP avoids the surface/subsurface defects mentioned above. As the key component, a capacitance coupled radio-fre-quency plasma torch is first introduced. In initial opera-tions, silicon wafers were machined as samples. Before applying operations, both the temperature distribution on the work-piece surface and the spatial gas diffusion in the machining process were studied qualitatively by finite element analysis. Then the following temperature measurement experiments demonstrate the formation of the temperature gradient on the wafer surface predicted by the theoretical analysis and indicated a peak temper-ature about 90℃ in the center. By using commercialized form talysurf, the machined surface was detected and the result shows regular removal profile that corresponds well to the flow field model. Moreover, the removal profile also indicates a 32 mm3/min removal rate. By using atomic force microscopy (AFM), the surface roughness was also measured and the result demonstrates an Ra 0.6 nm surface roughness. Then the element composition of the machined surface was detected and analyzed by X-ray photoelectron spectroscopy (XPS) technology. The results also demonstrate the occurrence of the anticipated main reactions. All the experiments have proved that

  4. Prediction and Optimization of Residual Stresses on Machined Surface and Sub-Surface in MQL Turning

    Science.gov (United States)

    Ji, Xia; Zou, Pan; Li, Beizhi; Rajora, Manik; Shao, Yamin; Liang, Steven Y.

    Residual stress in the machined surface and subsurface is affected by materials, machining conditions, and tool geometry and can affect the component life and service quality significantly. Empirical or numerical experiments are commonly used for determining residual stresses but these are very expensive. There has been an increase in the utilization of minimum quantity lubrication (MQL) in recent years in order to reduce the cost and tool/part handling efforts, while its effect on machined part residual stress, although important, has not been explored. This paper presents a hybrid neural network that is trained using Simulated Annealing (SA) and Levenberg-Marquardt Algorithm (LM) in order to predict the values of residual stresses in cutting and radial direction on the surface and within the work piece after the MQL face turning process. Once the ANN has successfully been trained, an optimization procedure, using Genetic Algorithm (GA), is applied in order to find the best cutting conditions in order to minimize the surface tensile residual stresses and maximize the compressive residual stresses within the work piece. The optimization results show that the usage of MQL decreases the surface tensile residual stresses and increases the compressive residual stresses within the work piece.

  5. EQUIVALENT NORMAL CURVATURE APPROACH MILLING MODEL OF MACHINING FREEFORM SURFACES

    Institute of Scientific and Technical Information of China (English)

    YI Xianzhong; MA Weiguo; QI Haiying; YAN Zesheng; GAO Deli

    2008-01-01

    A new milling methodology with the equivalent normal curvature milling model machining freeform surfaces is proposed based on the normal curvature theorems on differential geometry. Moreover, a specialized whirlwind milling tool and a 5-axis CNC horizontal milling machine are introduced. This new milling model can efficiently enlarge the material removal volume at the tip of the whirlwind milling tool and improve the producing capacity. The machining strategy of this model is to regulate the orientation of the whirlwind milling tool relatively to the principal directions of the workpiece surface at the point of contact, so as to create a full match with collision avoidance between the workpiece surface and the symmetric rotational surface of the milling tool. The practical results show that this new milling model is an effective method in machining complex three- dimensional surfaces. This model has a good improvement on finishing machining time and scallop height in machining the freeform surfaces over other milling processes. Some actual examples for manufacturing the freeform surfaces with this new model are given.

  6. Analyzing the Effect of Machining Parameters Setting to the Surface Roughness during End Milling of CFRP-Aluminium Composite Laminates

    Directory of Open Access Journals (Sweden)

    M. Nurhaniza

    2016-01-01

    Full Text Available The quality of the machining is measured from surface finished and it is considered as the most important aspect in composite machining. An appropriate and optimum machining parameters setting is crucial during machining operation in order to enhance the surface quality. The objective of this research is to analyze the effect of machining parameters on the surface quality of CFRP-Aluminium in CNC end milling operation with PCD tool. The milling parameters evaluated are spindle speed, feed rate, and depth of cut. The L9 Taguchi orthogonal arrays, signal-to-noise (S/N ratio, and analysis of variance (ANOVA are employed to analyze the effect of these cutting parameters. The analysis of the results indicates that the optimal cutting parameters combination for good surface finish is high cutting speed, low feed rate, and low depth of cut.

  7. Surface Analysis of Metal Materials After Water Jet Abrasive Machining

    Directory of Open Access Journals (Sweden)

    Pavel Polák

    2015-01-01

    Full Text Available In this article, we deal with a progressive production technology using the water jet cutting technology with the addition of abrasives for material removal. This technology is widely used in cutting various shapes, but also for the technology of machining such as turning, milling, drilling and cutting of threads. The aim of this article was to analyse the surface of selected types of metallic materials after abrasive machining, i.e. by assessing the impact of selected machining parameters on the surface roughness of metallic materials.

  8. Enhanced osteoblast response to electrical discharge machining surface.

    Science.gov (United States)

    Otsuka, Fukunaga; Kataoka, Yu; Miyazaki, Takashi

    2012-01-01

    The purpose of this study is to investigate the surface characteristics and biocompatibility of titanium (Ti) surfaces modified by wire electrical discharge machining (EDM). EDM surface characteristics were evaluated by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), thin-film X-ray diffractometry (XRD) and contact angle measurements. MC3T3-E1 cell morphology, attachment and proliferation, as well as analysis of osteoblastic gene expressions, on machined surfaces and EDM surfaces were also evaluated. EDM surfaces exhibited high super hydrophilicity, due to high surface energy. XPS and XRD revealed that a passive oxide layer with certain developing thickness onto. EDM surfaces promoted cell attachment, but restrained proliferation. Counted cell numbers increased significantly on the machined surfaces as compared to the EDM surfaces. Real-time PCR analyses showed significantly higher relative mRNA expression levels of osteoblastic genes (ALP, osteocalcin, Runx2, Osterix) in cells cultured on the EDM surfaces as compared to cells cultured on the machined surfaces.

  9. Generation of gear tooth surfaces by application of CNC machines

    Science.gov (United States)

    Litvin, F. L.; Chen, N. X.

    1994-01-01

    This study will demonstrate the importance of application of computer numerically controlled (CNC) machines in generation of gear tooth surfaces with new topology. This topology decreases gear vibration and will extend the gear capacity and service life. A preliminary investigation by a tooth contact analysis (TCA) program has shown that gear tooth surfaces in line contact (for instance, involute helical gears with parallel axes, worm gear drives with cylindrical worms, etc.) are very sensitive to angular errors of misalignment that cause edge contact and an unfavorable shape of transmission errors and vibration. The new topology of gear tooth surfaces is based on the localization of bearing contact, and the synthesis of a predesigned parabolic function of transmission errors that is able to absorb a piecewise linear function of transmission errors caused by gear misalignment. The report will describe the following topics: description of kinematics of CNC machines with six degrees of freedom that can be applied for generation of gear tooth surfaces with new topology. A new method for grinding of gear tooth surfaces by a cone surface or surface of revolution based on application of CNC machines is described. This method provides an optimal approximation of the ground surface to the given one. This method is especially beneficial when undeveloped ruled surfaces are to be ground. Execution of motions of the CNC machine is also described. The solution to this problem can be applied as well for the transfer of machine tool settings from a conventional generator to the CNC machine. The developed theory required the derivation of a modified equation of meshing based on application of the concept of space curves, space curves represented on surfaces, geodesic curvature, surface torsion, etc. Condensed information on these topics of differential geometry is provided as well.

  10. The Development of a Distributed Surface Machining System

    Institute of Scientific and Technical Information of China (English)

    Y.C.Kao; M.S.Chen

    2006-01-01

    This paper focuses on the development of a distributed surface machining system. Traditional manufacturing engineering activity analysis has been conducted in developing the proposed system structure. The advantages of a distributed system structure such as easy to manage, high expandability and flexibility will enhance the efficiency of an integral system operation, and achieve the goal of networked manufacture. The IDEF0 was used to describe each stage of the traditional surface machining activities, and then UML (Unified Modeling Language) technology was adopted to verify the feasibility and accuracy of the established integrated system. The developed distributed system structure and sub-functional modules (CAD/CAM/CAPP) have been implemented based on the proposed systematic approach; and a freeform surface has been used as an example for verification. The proposed approach has been successfully implemented and could be adopted to assist engineers in integrating machining activities that are located in dispersed places; and various domains experts also can exchange their expertise among themselves. Thus, the development time of a product machining processes can be shortened and so is its enhancement on the competitive advantages. In addition, this distributed system has also integrated multi-functional ontology and service agent to facilitate the selection and reconfiguration in manufacturing customization.The proposed system has presented the feasibility in incorporating the agent-based technology in a distributed freeform surface machining environment. Service agents communicate via pre-defined performatives underlying knowledge query and manipulation language (KQML) for the surface machining capability. The developed system has then successfully demonstrated the feasibility in implementing the agent-based technology into a distributed surface machining system.

  11. Machining of Additively Manufactured Parts: Implications for Surface Integrity

    OpenAIRE

    Oyelola, O.; Crawforth, P.; M'Saoubi, R.; Clare, A.T.

    2016-01-01

    Additive manufacturing methods continue to move towards production ready technologies with the widely extolled virtues of rapid transition from design to part and enhanced design freedoms. However, due to fundamental limitations of laser based processes for metal additive manufacturing, there is a significant ongoing need for these parts to be subject to additional machining operations. This paper reports on a study to investigate the machining behavior and surface integrity of Ti-6Al-4 V com...

  12. Machining of Additively Manufactured Parts: Implications for Surface Integrity

    OpenAIRE

    Oyelola, O.; Crawforth, P.; M'Saoubi, R.; Clare, A.T.

    2016-01-01

    Additive manufacturing methods continue to move towards production ready technologies with the widely extolled virtues of rapid transition from design to part and enhanced design freedoms. However, due to fundamental limitations of laser based processes for metal additive manufacturing, there is a significant ongoing need for these parts to be subject to additional machining operations. This paper reports on a study to investigate the machining behavior and surface integrity of Ti-6Al-4 V com...

  13. Characterization of micro machined surface from TRIP/TWIP steels

    Directory of Open Access Journals (Sweden)

    Smaga M.

    2015-01-01

    Full Text Available In this contribution micro machining induced changes in surface morphology, including phase transformation from fcc-austenite into hcp- and bcc-martensite as well as defined surface topography of TRIP/TWIP steel was characterized by scanning electron microscopy using electron backscatter diffraction (EBSD technique. For this, applying micro milling and micro grinding processes with tool diameter of 45 µm, structures were machined into flat specimen surfaces of X30MnAl17–1 steel in defined areas previously characterized by EBSD.

  14. Surface errors in the course of machining precision optics

    Science.gov (United States)

    Biskup, H.; Haberl, A.; Rascher, R.

    2015-08-01

    Precision optical components are usually machined by grinding and polishing in several steps with increasing accuracy. Spherical surfaces will be finished in a last step with large tools to smooth the surface. The requested surface accuracy of non-spherical surfaces only can be achieved with tools in point contact to the surface. So called mid-frequency errors (MSFE) can accumulate with zonal processes. This work is on the formation of surface errors from grinding to polishing by conducting an analysis of the surfaces in their machining steps by non-contact interferometric methods. The errors on the surface can be distinguished as described in DIN 4760 whereby 2nd to 3rd order errors are the so-called MSFE. By appropriate filtering of the measured data frequencies of errors can be suppressed in a manner that only defined spatial frequencies will be shown in the surface plot. It can be observed that some frequencies already may be formed in the early machining steps like grinding and main-polishing. Additionally it is known that MSFE can be produced by the process itself and other side effects. Beside a description of surface errors based on the limits of measurement technologies, different formation mechanisms for selected spatial frequencies are presented. A correction may be only possible by tools that have a lateral size below the wavelength of the error structure. The presented considerations may be used to develop proposals to handle surface errors.

  15. Video Quality Assessment and Machine Learning: Performance and Interpretability

    DEFF Research Database (Denmark)

    Søgaard, Jacob; Forchhammer, Søren; Korhonen, Jari

    2015-01-01

    In this work we compare a simple and a complex Machine Learning (ML) method used for the purpose of Video Quality Assessment (VQA). The simple ML method chosen is the Elastic Net (EN), which is a regularized linear regression model and easier to interpret. The more complex method chosen is Support...

  16. Integrated quality control architecture for multistage machining processes

    Science.gov (United States)

    Yang, Jie; Liu, Guixiong

    2010-12-01

    To solve problems concerning the process quality prediction control for the multistage machining processes, a integrated quality control architecture is proposed in this paper. First, a hierarchical multiple criteria decision model is established for the key process and the weight matrix method stratified is discussed. Predictive control of the manufacturing quality is not just for on-site monitoring and control layer, control layer in the enterprise, remote monitoring level of quality exists a variety of target predictive control demand, therefore, based on XML to achieve a unified description of manufacturing quality information, and in different source of quality information between agencies to achieve the transfer and sharing. This will predict complex global quality control, analysis and diagnosis data to lay a good foundation to achieve a more practical, open and standardized manufacturing quality with higher levels of information integration system.

  17. Power quality in power systems and electrical machines

    CERN Document Server

    Fuchs, Ewald

    2015-01-01

    The second edition of this must-have reference covers power quality issues in four parts, including new discussions related to renewable energy systems. The first part of the book provides background on causes, effects, standards, and measurements of power quality and harmonics. Once the basics are established the authors move on to harmonic modeling of power systems, including components and apparatus (electric machines). The final part of the book is devoted to power quality mitigation approaches and devices, and the fourth part extends the analysis to power quality solutions for renewable

  18. MAGNETO-ABRASIVE MACHINING OF SURFACES FORMED BY ELECTROMAGNET SURFACING WITH PLASTIC DEFORMATION

    Directory of Open Access Journals (Sweden)

    Zh. A. Mrochek

    2011-01-01

    Full Text Available The paper presents investigation results pertaining to magneto-abrasive machining of product surfaces formed by electromagnet surfacing with a plastic deformation of P6M5K5 powder. 

  19. Development of a copy-peeling machine for machining the surface of hot rolled square billets

    Science.gov (United States)

    Koch, R. E.; Fangmeier, R.; Seppelt, B.

    1986-01-01

    A copy-peeling system to replace the high-pressure grinding method, especially for stainless steel qualities, was developed. The copy-peeling process for square billets was accomplished on an existing planing machine with special test attachments as well as on a specially developed copy-peeling machine. The attainable material removals and the tool life reached during the tests with stainless steel are not sufficient to offer an economic and technically advanced alternative to high-pressure grinding. The advantages of copy peeling with respect to safety and health of the operational personnel are obvious. However, it cannot be expected that this process will be applied extensively.

  20. MICRO/NANO-MACHINING ON SILICON SURFACE WITH A MODIFIED ATOMIC FORCE MICROSCOPE

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    To understand the deformation and removal mechanism of material on nano-scale and at ultralow loads, a systemic study on AFM micro/nano-machining on single crystal silicon is conducted. The results indicate that AFM nanomachining has a precisely dimensional controllability and a good surface quality on nanometer scale. A SEM is adopted to observe nano-machined region and chips, the results indicate that the material removal mechanisms change with the applied normal load. An XPS is used to analyze the changes of chemical composition inside and outside the nano-machined region respectively. The nano-indentation which is conducted with the same AFM diamond tip on the machined region shows a big discrepancy compared with that on the macro-scale. The calculated results show higher nano-hardness and elastic modulus than normal values. This phenomenon can be regarded as the indentation size effect(ISE).

  1. Influence of Machine Exploitation Effectiveness on Furniture Production Quality Level

    Directory of Open Access Journals (Sweden)

    Stasiak-Betlejewska Renata

    2015-12-01

    Full Text Available One of the most important factors determining the company‘s capacity to produce high quality products is the level of machinery operation effectiveness. Companies having modern machinery are characterized by high productivity. To obtain a high quality product, the equipment should be properly used, without any failure, which contributes significantly to the exploitation level increase. The modernity level and the exploitation effectiveness level for chosen machine producing furniture components in relation to the product quality level were analysed in the paper. As a result of the research findings analysis, proposals for corrective actions with regard to machinery maintenance and production processes were presented.

  2. Surface quality in rapid prototype MMD process

    Directory of Open Access Journals (Sweden)

    Lisandro Vargas Henríquez

    2010-04-01

    Full Text Available This article summarises a Manufacturing Materials and Processes MSc thesis written for the Mechanical and Electrical Engineering Department. The paper shows the interaction of process, gap (deposition distance and extursion terminal velocity modelled process parameters for CEIF's (Centro de Equipos Interfacultades rapid prototype molten material deposit (MMD Titan SH-1 machine by analysing prototupes improved surface quality and resistence to tension and characterising material. The project applies experimental design criteria for orientating the selection of experimental process parameters. Acrylonitrile-buttadin-styrene (ABS had alredy been mechanically and physicochemically characterised (i.e the material used in the MMD process.

  3. Investigation on Surface Roughness of Inconel 718 in Photochemical Machining

    Directory of Open Access Journals (Sweden)

    Nitin D. Misal

    2017-01-01

    Full Text Available The present work is focused on estimating the optimal machining parameters required for photochemical machining (PCM of an Inconel 718 and effects of these parameters on surface topology. An experimental analysis was carried out to identify optimal values of parameters using ferric chloride (FeCl3 as an etchant. The parameters considered in this analysis are concentration of etchant, etching time, and etchant temperature. The experimental analysis shows that etching performance as well as surface topology improved by appropriate selection of etching process parameters. Temperature of the etchant found to be dominant parameter in the PCM of Inconel 718 for surface roughness. At optimal etching conditions, surface roughness was found to be 0.201 μm.

  4. FFT and Wavelet-Based Analysis of the Influence of Machine Vibrations on Hard Turned Surface Topographies

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    With hard turning, which is an attractive alternative to existing grinding processes, surface quality is of great importance. Signal processing techniques were used to relate workpiece surface topography to the dynamic behavior of the machine tool. Spatial domain frequency analyses based on fast Fourier transform were used to analyze the tool behavior. Wavelet reconstruction was used for profile filtering. The results show that machine vibration remarkably affects the surface topography at small feed rates, but has negligible effect at high feed rates. The analyses also show how to control the surface quality during hard turning.

  5. Finger vein image quality evaluation using support vector machines

    Science.gov (United States)

    Yang, Lu; Yang, Gongping; Yin, Yilong; Xiao, Rongyang

    2013-02-01

    In an automatic finger-vein recognition system, finger-vein image quality is significant for segmentation, enhancement, and matching processes. In this paper, we propose a finger-vein image quality evaluation method using support vector machines (SVMs). We extract three features including the gradient, image contrast, and information capacity from the input image. An SVM model is built on the training images with annotated quality labels (i.e., high/low) and then applied to unseen images for quality evaluation. To resolve the class-imbalance problem in the training data, we perform oversampling for the minority class with random-synthetic minority oversampling technique. Cross-validation is also employed to verify the reliability and stability of the learned model. Our experimental results show the effectiveness of our method in evaluating the quality of finger-vein images, and by discarding low-quality images detected by our method, the overall finger-vein recognition performance is considerably improved.

  6. Process parameters effect on material removal mechanism and cut quality of abrasive water jet machining

    Directory of Open Access Journals (Sweden)

    Janković P.

    2013-01-01

    Full Text Available The process of the abrasive water jet cutting of materials, supported by the theories of fluid mechanics, abrasive wear and damage mechanics, is a high-tech technologies that provides unique capabilities compared to conventional machining processes. This paper, along the theoretical derivations, provides original contributions in the form of mathematical models of the quantity of the cut surface damage, expressed by the values of cut surface roughness. The particular part of this paper deal with the results of the original experimental research. The research aim was connected with the demands of industry, i.e. the end user. Having in mind that the conventional machining processes are not only lagging behind in terms of quality of cut, or even some requests are not able to meet, but with the advent of composite materials were not able to machine them, because they occurred unacceptable damage (mechanical damage or delamination, fiber pull-out, burning, frayed edges.

  7. Influence Factors of Surface Quality in Combined Machining of Ultrasonic Vibration Assisted EDM in Gas Medium%超声振动-气体介质电火花复合加工中表面质量的影响因素

    Institute of Scientific and Technical Information of China (English)

    郭谆钦; 王承文

    2011-01-01

    This paper introduces a new technology named ultrasonic vibration assisted gas medium electrical discharge machining. Study on the influence factors of surface quality in the combined machining of ultrasonic vibration assisted electrical discharge machining in gas medium through analyses and experiments, and the improving methods is proposed.%介绍了一种新兴的加工技术,超声振动-气体介质电火花复合加工技术.通过分析和实验探讨超声振动-气体介质电火花复合加工中影响表面质量的因素,并提出改进措施.

  8. Machine Vision-Based Measurement Systems for Fruit and Vegetable Quality Control in Postharvest.

    Science.gov (United States)

    Blasco, José; Munera, Sandra; Aleixos, Nuria; Cubero, Sergio; Molto, Enrique

    2017-03-14

    Individual items of any agricultural commodity are different from each other in terms of colour, shape or size. Furthermore, as they are living thing, they change their quality attributes over time, thereby making the development of accurate automatic inspection machines a challenging task. Machine vision-based systems and new optical technologies make it feasible to create non-destructive control and monitoring tools for quality assessment to ensure adequate accomplishment of food standards. Such systems are much faster than any manual non-destructive examination of fruit and vegetable quality, thus allowing the whole production to be inspected with objective and repeatable criteria. Moreover, current technology makes it possible to inspect the fruit in spectral ranges beyond the sensibility of the human eye, for instance in the ultraviolet and near-infrared regions. Machine vision-based applications require the use of multiple technologies and knowledge, ranging from those related to image acquisition (illumination, cameras, etc.) to the development of algorithms for spectral image analysis. Machine vision-based systems for inspecting fruit and vegetables are targeted towards different purposes, from in-line sorting into commercial categories to the detection of contaminants or the distribution of specific chemical compounds on the product's surface. This chapter summarises the current state of the art in these techniques, starting with systems based on colour images for the inspection of conventional colour, shape or external defects and then goes on to consider recent developments in spectral image analysis for internal quality assessment or contaminant detection.

  9. Evaluation of Fatigue Behavior and Surface Characteristics of Aluminum Alloy 2024 T6 After Electric Discharge Machining

    Science.gov (United States)

    Mehmood, Shahid; Shah, Masood; Pasha, Riffat Asim; Sultan, Amir

    2017-09-01

    The effect of electric discharge machining (EDM) on surface quality and consequently on the fatigue performance of Al 2024 T6 is investigated. Five levels of discharge current are analyzed, while all other electrical and nonelectrical parameters are kept constant. At each discharge current level, dog-bone specimens are machined by generating a peripheral notch at the center. The fatigue tests are performed on four-point rotating bending machine at room temperature. For comparison purposes, fatigue tests are also performed on the conventionally machined specimens. Linearized SN curves for 95% failure probability and with four different confidence levels (75, 90, 95 and 99%) are plotted for each discharge current level as well as for conventionally machined specimens. These plots show that the electric discharge machined (EDMed) specimens give inferior fatigue behavior as compared to conventionally machined specimen. Moreover, discharge current inversely affects the fatigue life, and this influence is highly pronounced at lower stresses. The EDMed surfaces are characterized by surface properties that could be responsible for change in fatigue life such as surface morphology, surface roughness, white layer thickness, microhardness and residual stresses. It is found that all these surface properties are affected by changing discharge current level. However, change in fatigue life by discharge current could not be associated independently to any single surface property.

  10. Machine-tool control system for turning nonaxisymmetric surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Douglass, S.S.; Green, W.L.

    1979-09-01

    A development program has been initiated to allow on-axis turning of nonaxisymmetric surfaces. A short-travel high-speed slide is mounted on a precision, numerically controlled, two-axis turning machine. The motion of the auxiliary slide is synchronized with the spindle and the two remaining slides. The report defines the workpiece geometry and requirements, calculations for the slide motion, techniques for real-time command generation, and planned equipment set.

  11. A Tool Path Generation Strategy for Sculptured Surfaces Machining

    Institute of Scientific and Technical Information of China (English)

    Chen Tao; Zhong Yifang; Zhou Ji

    2001-01-01

    This paper presents a strategy to generate interference-free tool paths for machiningsculptured surfaces. The strategy proposed here is first to determine the tool path topology. Thevalues of the step length and the path interval are then calculated based on the machining tolerancerequirements. After detecting and eliminating the tool interference, the interference-free tool path isgenerated. The effectiveness of the developed algorithm is demonstrated through simulation andactual cutting tests.

  12. Machine Learning Tools for Geomorphic Mapping of Planetary Surfaces

    OpenAIRE

    Stepinski, Tomasz F.; Vilalta, Ricardo

    2010-01-01

    Geomorphic auto-mapping of planetary surfaces is a challenging problem. Here we have described how machine learning techniques, such as clustering or classification, can be utilized to automate the process of geomorphic mapping for exploratory and exploitation purposes. Relatively coarse resolution of planetary topographic data limits the number of features that can be used in the learning process and makes planetary auto-mapping more challenging than terrestrial auto-mapping. With this cavea...

  13. Machining with abrasives

    CERN Document Server

    Jackson, Mark J

    2011-01-01

    Abrasive machining is key to obtaining the desired geometry and surface quality in manufacturing. This book discusses the fundamentals and advances in the abrasive machining processes. It provides a complete overview of developing areas in the field.

  14. Experimental study of surface roughness in Electric Discharge Machining (EDM based on Grey Relational Analysis

    Directory of Open Access Journals (Sweden)

    Mat Deris Ashanira

    2016-01-01

    Full Text Available Electric Discharge Machining (EDM is one of the modern machining which is capable in handling hard and difficult-to-machine material. The successful of EDM basically depends on its performances such as surface roughness (Ra, material removal rate (MRR, electrode wear rate (EWR and dimensional accuracy (DA. Ra is considered as the most important performance due to it role as a technological quality measurement for a product and also a factor that significantly affects the manufacturing process. This paper presents the experimental study of surface roughness in die sinking EDM using stainless steel SS316L with copper impregnated graphite electrode. The machining experimental is conducted based on the two levels full factorial design of design of experiment (DOE with five machining parameters which are peak current, servo voltage, servo speed, pulse on time and pulse off time. The results were analyzed using grey relational analysis (GRA and it was found that pulse on time and servo voltage give the most influence to the Ra value.

  15. Ensuring uniformity of strengthening for machine parts surfaces by shot-peening

    Directory of Open Access Journals (Sweden)

    Z.A. Stotsko

    2010-11-01

    Full Text Available Purpose: of this paper is developing the mathematical models of shot-peening, in which is reflected moving shot-peening head or machine parts surfaces during treating that will achieve uniformity of treatment machine parts.Design/methodology/approach: The main methods used for the theoretical research are mathematical modelling, integral calculus, fundamentals of analytic geometry, probability theory. It is used approved enough and well known numerical methods for calculations after mathematical models.Findings: Method of mathematical modeling for shot-peening is developed based on the energy conception. Mathematical model in which is reflected moving shot-peened head or machine parts surfaces during treating is created. It allows forecasting the characteristics of surface quality depending on the technological modes of treatment.Research limitations/implications: It is planned developing and improving the methods of shot-peening mathematical modeling in future research by extending theirs for the curvilinear treated surfaces, which has movement relative to the nozzle of shot-peening head after the different laws of motion, and for different kinds of materials, especially for metal joint endoprosthesis biomaterials.Practical implications: has the applied software, elaborated on the basis of the models, that allows providing for automation of calculations of the characteristics of surface quality depending on the technological modes of treatment.Originality/value: It is pioneered receiving functional dependences in which is reflected moving shot-peened head or machine parts surfaces during treating. Created functional dependences takes into account the distribution of characteristics of working medium (mass and velocity all along the cross-sections of shot blast.

  16. A system framework of inter-enterprise machining quality control based on fractal theory

    Science.gov (United States)

    Zhao, Liping; Qin, Yongtao; Yao, Yiyong; Yan, Peng

    2014-03-01

    In order to meet the quality control requirement of dynamic and complicated product machining processes among enterprises, a system framework of inter-enterprise machining quality control based on fractal was proposed. In this system framework, the fractal-specific characteristic of inter-enterprise machining quality control function was analysed, and the model of inter-enterprise machining quality control was constructed by the nature of fractal structures. Furthermore, the goal-driven strategy of inter-enterprise quality control and the dynamic organisation strategy of inter-enterprise quality improvement were constructed by the characteristic analysis on this model. In addition, the architecture of inter-enterprise machining quality control based on fractal was established by means of Web service. Finally, a case study for application was presented. The result showed that the proposed method was available, and could provide guidance for quality control and support for product reliability in inter-enterprise machining processes.

  17. Improved Quality Prediction Model for Multistage Machining Process Based on Geometric Constraint Equation

    Institute of Scientific and Technical Information of China (English)

    ZHU Limin; HE Gaiyun; SONG Zhanjie

    2016-01-01

    Product variation reduction is critical to improve process efficiency and product quality, especially for multistage machining process (MMP). However, due to the variation accumulation and propagation, it becomes quite difficult to predict and reduce product variation for MMP. While the method of statistical process control can be used to control product quality, it is used mainly to monitor the process change rather than to analyze the cause of product variation. In this paper, based on a differential description of the contact kinematics of locators and part surfaces, and the geometric constraints equation defined by the locating scheme, an improved analytical variation propagation model for MMP is presented. In which the influence of both locator position and machining error on part quality is considered while, in traditional model, it usually focuses on datum error and fixture error. Coordinate transformation theory is used to reflect the generation and transmission laws of error in the establishment of the model. The concept of deviation matrix is heavily applied to establish an explicit mapping between the geometric deviation of part and the process error sources. In each machining stage, the part deviation is formulized as three separated components corresponding to three different kinds of error sources, which can be further applied to fault identification and design optimization for complicated machining process. An example part for MMP is given out to validate the effectiveness of the methodology. The experiment results show that the model prediction and the actual measurement match well. This paper provides a method to predict part deviation under the influence of fixture error, datum error and machining error, and it enriches the way of quality prediction for MMP.

  18. Hierarchical planning for a surface mounting machine placement

    Institute of Scientific and Technical Information of China (English)

    曾又姣; 马登哲; 金烨; 严隽琪

    2004-01-01

    For a surface mounting machine (SMM) in printed circuit board (PCB) assembly line, there are four problems, e.g. CAD data conversion, nozzle selection, feeder assignment and placement sequence determination. A hierarchical planning for them to maximize the throughput rate of an SMM is presented here. To minimize set-up time, a CAD data conversion system was first applied that could automatically generate the data for machine placement from CAD design data files. Then an effective nozzle selection approach was implemented to minimize the time of nozzle changing. And then, to minimize picking time, an algorithm for feeder assignment was used to make picking multiple components simultaneously as much as possible. Finally, in order to shorten pick-and-place time, a heuristic algorithm was used to determine optimal component placement sequence according to the decided feeder positions. Experiments were conducted on a four head SMM. The experimental results were used to analyse the assembly line performance.

  19. Air quality monitoring using mobile microscopy and machine learning

    KAUST Repository

    Wu, Yi-Chen

    2017-09-08

    Rapid, accurate and high-throughput sizing and quantification of particulate matter (PM) in air is crucial for monitoring and improving air quality. In fact, particles in air with a diameter of ≤2.5 μm have been classified as carcinogenic by the World Health Organization. Here we present a field-portable cost-effective platform for high-throughput quantification of particulate matter using computational lens-free microscopy and machine-learning. This platform, termed c-Air, is also integrated with a smartphone application for device control and display of results. This mobile device rapidly screens 6.5 L of air in 30 s and generates microscopic images of the aerosols in air. It provides statistics of the particle size and density distribution with a sizing accuracy of ~93%. We tested this mobile platform by measuring the air quality at different indoor and outdoor environments and measurement times, and compared our results to those of an Environmental Protection Agency–approved device based on beta-attenuation monitoring, which showed strong correlation to c-Air measurements. Furthermore, we used c-Air to map the air quality around Los Angeles International Airport (LAX) over 24 h to confirm that the impact of LAX on increased PM concentration was present even at >7 km away from the airport, especially along the direction of landing flights. With its machine-learning-based computational microscopy interface, c-Air can be adaptively tailored to detect specific particles in air, for example, various types of pollen and mold and provide a cost-effective mobile solution for highly accurate and distributed sensing of air quality.

  20. Specific Features of Chip Making and Work-piece Surface Layer Formation in Machining Thermal Coatings

    Directory of Open Access Journals (Sweden)

    V. M. Yaroslavtsev

    2016-01-01

    Full Text Available A wide range of unique engineering structural and performance properties inherent in metallic composites characterizes wear- and erosion-resistant high-temperature coatings made by thermal spraying methods. This allows their use both in manufacturing processes to enhance the wear strength of products, which have to operate under the cyclic loading, high contact pressures, corrosion and high temperatures and in product renewal.Thermal coatings contribute to the qualitative improvement of the technical level of production and product restoration using the ceramic composite materials. However, the possibility to have a significantly increased product performance, reduce their factory labour hours and materials/output ratio in manufacturing and restoration is largely dependent on the degree of the surface layer quality of products at their finishing stage, which is usually provided by different kinds of machining.When machining the plasma-sprayed thermal coatings, a removing process of the cut-off layer material is determined by its distinctive features such as a layered structure, high internal stresses, low ductility material, high tendency to the surface layer strengthening and rehardening, porosity, high abrasive properties, etc. When coatings are machined these coating properties result in specific characteristics of chip formation and conditions for formation of the billet surface layer.The chip formation of plasma-sprayed coatings was studied at micro-velocities using an experimental tool-setting microscope-based setup, created in BMSTU. The setup allowed simultaneous recording both the individual stages (phases of the chip formation process and the operating force factors.It is found that formation of individual chip elements comes with the multiple micro-cracks that cause chipping-off the small particles of material. The emerging main crack in the cut-off layer of material leads to separation of the largest chip element. Then all the stages

  1. Study on Surface Engineering of Normalized Steels Subjected To Machine

    Institute of Scientific and Technical Information of China (English)

    Hardening

    2004-01-01

    Engineering the surfaces of components to improve the life and performance of parts used in automotive and aerospace engineering is the active area of research. Suitable Thermal/Mechanical/Thermo mechanical surface engineering treatments will produce extensive rearrangement of atoms in metals and alloys and corresponding marked variations in Physical, Chemical and Mechanical properties. Among the more important of these treatments are heat treatment processes such as hardening by Quenching, Induction hardening and Case Carburizing which rely on phase transformations to produce desired changes in mechanical properties. Other processes where phase transformation occur are casting, welding and machining etc. [1] Phase transformation may be homogeneous or heterogeneous. Homogeneous involves rearrangements in the structure of the material taking place simultaneously in all parts of the solid, while the heterogeneous transformation involves structural changes which are more localized. Alternatively they could be called as Isothermal and Nonisothermal transformation. But irrespective of the classification, these transformations alter the structure of the material giving rise to changes in the mechanical and physical properties of the processed material. It is of interest to review some consequences of surface modification in isothermal (Normalizing) and nonisothermal transformations (Machining) of low carbon steels.

  2. Adaptive compensation of sculptured surface machining errors by open architecture manufacturing system

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Presents the adaptive compensation of sculptured surfacemachining errors by using the open architecture intelligent manufacturing system to ensure real-time high-precision machining of sculptured surface, and the tool deflection model constructed for prediction of machining errors to be compensated and analysis of the effect of tool deflection on machining errors, and concludes from experimental results that the open architecture intelligent manufacturing system can effectively improve the machining precision and reduce the machining errors by 30%.

  3. Standard surface grinder for precision machining of thin-wall tubing

    Science.gov (United States)

    Jones, A.; Kotora, J., Jr.; Rein, J.; Smith, S. V.; Strack, D.; Stuckey, D.

    1967-01-01

    Standard surface grinder performs precision machining of thin-wall stainless steel tubing by electrical discharge grinding. A related adaptation, a traveling wire electrode fixture, is used for machining slots in thin-walled tubing.

  4. Machine Learning and Software Quality Prediction: As an Expert System

    Directory of Open Access Journals (Sweden)

    Ekbal A. Rashid

    2014-04-01

    Full Text Available To improve the software quality the number of errors from the software must be removed. The research paper presents a study towards machine learning and software quality prediction as an expert system. The purpose of this paper is to apply the machine learning approaches, such as case-based reasoning, to predict software quality. The main objective of this research is to minimize software costs. Predict the error in software module correctly and use the results in future estimation. The novel idea behind this system is that Knowledge base (KBS building is an important task in CBR and the knowledge base can be built based on world new problems along with world new solutions. Second, reducing the maintenance cost by removing the duplicate record set from the KBS. Third, error prediction with the help of similarity functions. In this research four similarity functions have been used and these are Euclidean, Manhattan, Canberra, and Exponential. We feel that case-based models are particularly useful when it is difficult to define actual rules about a problem domain. For this purpose we have developed a case-based reasoning model and have validated it upon student data. It was observed that, Euclidean and Exponential both are good for error calculation in comparison to Manhattan and Canberra after performing five experiments. In order to obtain a result we have used indigenous tool. For finding the mean and standard deviation, SPSS version 16 and for generating graphs MATLAB 7.10.0 version have been used as an analyzing tool.

  5. [Backscattering Characteristics of Machining Surfaces and Retrieval of Surface Multi-Parameters].

    Science.gov (United States)

    Tao, Hui-rong; Zhang, Fu-min; Qu, Xing-hua

    2015-07-01

    For no cooperation target laser ranging, the backscattering properties of the long-range and real machined surfaces are uncertain which seriously affect the ranging accuracy. It is an important bottleneck restricting the development of no cooperation ranging technology. In this paper, the backscattering characteristics of three typical machining surfaces (vertidal milling processing method, horizontal milling processing method and plain grinding processing method) under the infrared laser irradiation with 1550 nm were measured. The relation between the surface nachining texture, incident azimuth, roughness and the backscattering distribution were analyzed and the reasons for different processing methods specific backscattering field formed were explored. The experimental results show that the distribution of backscattering spectra is greatly affected by the machined processing methods. Incident angle and roughness have regularity effect on the actual rough surface of each mode. To be able to get enough backscattering, knowing the surface texture direction and the roughness of machined metal is essential for the optimization of the non-contact measurement program in industry. On this basis, a method based on an artificial neural network (ANN) and genetic algorithm (GA), is proposed to retrieve the surface multi-parameters of the machined metal. The generalized regression neural network (GRNN) was investigated and used in this application for the backscattering modeling. A genetic algorithm was used to retrieve the multi-parameters of incident azimuth angle, roughness and processing methods of machined metal sur face. Another processing method of sample (planer processing method) was used to validate data. The final results demonstrated that the method presented was efficient in parameters retrieval tasks. This model can accurately distinguish processing methods and the relative error of incident azimuth and roughness is 1.21% and 1.03%, respectively. The inversion

  6. The Wear of the Focusing Tube and the Cut-Surface Quality

    Directory of Open Access Journals (Sweden)

    B. Nedic

    2010-06-01

    Full Text Available The wear of the focusing tube is a very important feature of the abrasive water jet machining. Of all rejected focusing tubes, 85% are worn. Similarly, the age of focusing tube influences the cut geometry and quality of machined surface. With regard to the stated, wearing of the focusing tube is subject of this paper. Focusing tube outlet diameter was measured as well as its influence on the surface quality.

  7. Hierarchical planning for a surface mounting machine placement

    Institute of Scientific and Technical Information of China (English)

    曾又姣; 马登哲; 金烨; 严隽琪

    2004-01-01

    For a surface mounting machine(SMM)in printed circuit board(PCB)assembly line,there are four problems,e.g. CAD data conversion,nozzle selection,feeder assignment and placement sequence determination. A hierarchical planning for them to maximize the throughput rate of an SMM is presented here. To minimize set-up time,a CAD data conversion system was first applied that could automatically generate the data for machine placement from CAD design data files. Then an effective nozzle selection approach was implemented to minimize the time of nozzle changing. And then,to minimize picking time,an algorithm for feeder assignment was used to make picking multiple components simultaneously as much as possible. Finally,in order to shorten pick-and-place time,a heuristic algorithm was used to determine optimal component placement sequence according to the decided feeder positions. Experiments were conducted on a four head SMM.The experimental results were used to analyse the assembly line performance.

  8. Cutting force and machine kinematics constrained cutter location planning for five-axis flank milling of ruled surfaces

    Directory of Open Access Journals (Sweden)

    Ke Xu

    2017-07-01

    Full Text Available Five-axis flank milling has been commonly used in the manufacturing of complex workpieces because of its greater productivity than that of three-axis or five-axis end milling. The advantage of this milling operation largely depends on effective cutter location planning. The finished surface sometimes suffers from large geometrical errors induced by improper tool positioning, due to the non-developability of most ruled surfaces in industrial applications. In addition, a slender flank-milling cutter may be deflected when subjected to large cutting forces during the machining process, further degrading the surface quality or even breaking the cutter. This paper proposes a novel tool path planning scheme to address those problems. A simple but effective algorithm is developed to adaptively allocate a series of cutter locations over the design surface with each one being confined within an angular rotation range. The allocation result satisfies a given constraint of geometrical errors on the finished surface, which consists of the tool positioning errors at each cutter location and the sweeping errors between consecutive ones. In addition, a feed rate scheduling algorithm is proposed to maximize the machining efficiency subject to the cutting force constraint and the kinematical constraints of a specific machine configuration. Simulation and experimental tests are conducted to validate the effectiveness of the proposed algorithms. Both the machining efficiency and finish surface quality are greatly improved compared with conventional cutter locations.

  9. Analysing Quality of English-Hindi Machine Translation Engine outputs using Baysian Classification

    OpenAIRE

    Rashmi Gupta; Nisheeth Joshi; Iti Mathur

    2013-01-01

    This paper considers the problem for estimating the quality of machine translation outputs which are independent of human intervention and are generally addressed using machine learning techniques.There are various measures through which a machine learns translations quality. Automatic Evaluation metrics produce good co-relation at corpus level but cannot produce the same results at the same segment or sentence level. In this paper 16 features are extracted from the input sentence...

  10. Quality of the surface of Coffea arabica wood

    Directory of Open Access Journals (Sweden)

    Pedro Paulo de Carvalho Braga

    2014-03-01

    Full Text Available The wood of Coffea arabica L. is considered a a residue of the coffee industry and is widely used as a source of energy. Few studies have shown other destinations such as the manufacture of small objects and furniture with rustic design. The objective of this work was to find the best fit in cutting speed during machining planer trowel the wood of Coffea arabica, taking into consideration the quality of the machined surface. The wood from the Coffea arabica came from an 15 years planting, spacing 3 x 2 m, of the municipality of Machado / MG. The tree was pruned, unfolded and flattened, in order for getting cut-proof of 30 mm thick, with variables length and width. The machining tests were performed at the Laboratory of Wood Machining (DCF / UFLA, varying the cutting speed in plane trowel. The qualification of the machined surface was performed by the feed per tooth (fz, visual analysis (ASTM D 1666-87 and roughness Ra and Rz. It was used a completely randomized design with 30 repetitions. We conducted the analysis of variance test and the average of Scott-Knott, at 5% significance level. It was calculated the percentage of marks obtained for the feed per tooth. The results showed that the quality of machined surface with cutting speeds of 19 and 21 m∙s-1 and forward speed of 6 m∙min-1 were satisfactory with small surveys of fiber and low values of feed per tooth ( fz and roughness Ra and Rz.

  11. Enabling ultra high precision on hard steels using surface defect machining

    OpenAIRE

    2014-01-01

    This paper is an extension to an idea coined during the 13th EUSPEN Conference (P6.23) named "surface defect machining" (SDM). The objective of this work was to demonstrate how a conventional CNC turret lathe can be used to obtain ultra high precision machined surface finish on hard steels without recourse to a sophisticated ultra precision machine tool. An AISI 4340 hard steel (69 HRC) workpiece was machined using a CBN cutting tool with and without SDM. Post-machining measurements by a Form...

  12. Influence of Motion Errors of Feed Drive Systems on Machined Surface

    Science.gov (United States)

    Nishio, Kentaro; Sato, Ryuta; Shirase, Keiichi

    The purpose of this study is to clarify the relationship between the dynamic motion errors of feed drive systems and the machined surfaces. To achieve this purpose, a simulation method for a machined surface by peripheral milling is proposed. In the proposed method, the motion errors of a feed drive system and the machined surface are simulated based on tool diameter, number of flutes, spindle speed, and feed speed. In addition, to clarify the correctness of the proposed method, actual cutting tests are carried out. In the cutting tests, the control parameters of the machine tool are intentionally changed to obtain the motion errors. As the results of the cutting tests, it is confirmed that the influence of the motion errors of feed drive systems on machined surface can be predicted by the proposed simulation method. The relationship between the motion errors and machined surfaces is also examined based on the simulations.

  13. Tool steel quality and surface finishing of plastic molds

    Directory of Open Access Journals (Sweden)

    Rafael Agnelli Mesquita

    2010-01-01

    Full Text Available Plastic industry is today in a constant growth, demanding several products from other segments, which includes the plastic molds, mainly used in the injection molding process. Considering all the requirements of plastic molds, the surface finishing is of special interest, as the injected plastic part is able to reproduce any details (and also defects from the mold surface. Therefore, several aspects on mold finishing are important, mainly related to manufacturing conditions - machining, grinding, polishing and texturing, and also related to the tool steel quality, in relation to microstructure homogeneity and non-metallic inclusions (cleanliness. The present paper is then focused on this interrelationship between steel quality and manufacturing process, which are both related to the final quality of plastic mold surfaces. Examples are discussed in terms of surface finishing of plastic molds and the properties or the microstructure of mold steels.

  14. 提高数控加工质量的工艺措施%Improve the Quality of NC Machining Process Measures

    Institute of Scientific and Technical Information of China (English)

    窦金平

    2012-01-01

    在数控加工中,除了受机床、刀具、夹具的制造误差和安装误差的影响外,加工质量还与数控加工中所采取的工艺措施密切相关.从加工工艺角度出发,论述了提高数控加工精度和零件表面加工质量的若干措施,以利于高效地使用数控机床.%In NC machining, in addition to effected by manufacture errors and installation errors of machine tool, tool, fixture, machining quality is closely related to process measures taken in NC machining. From the process point of view, a number of measures for improving NC machining accuracy and surface quality of parts were discussed so as to use NC machine tools efficiently.

  15. Surface roughness analysis after machining of direct laser deposited tungsten carbide

    Science.gov (United States)

    Wojciechowski, S.; Twardowski, P.; Chwalczuk, T.

    2014-03-01

    In this paper, an experimental surface roughness analysis in machining of tungsten carbide is presented. The tungsten carbide was received using direct laser deposition technology (DLD). Experiments carried out included milling of tungsten carbide samples using monolithic torus cubic boron nitride (CBN) tool and grinding with the diamond cup wheel. The effect of machining method on the generated surface topography was analysed. The 3D surface topographies were measured using optical surface profiler. The research revealed, that surface roughness generated after the machining of tungsten carbide is affected by feed per tooth (fz) value related to kinematic-geometric projection only in a minor extent. The main factor affecting machined surface roughness is the occurrence of micro grooves and protuberances on the machined surface, as well as other phenomena connected, inter alia, with the mechanism for material removal.

  16. Influence of Paper Surface Compounds on Corrosion of Printing Machines

    Directory of Open Access Journals (Sweden)

    Kresimir Dragcevic

    2013-01-01

    Full Text Available This paper deals with investigation of corrosion processes on construction steel in contact with aqueous solutions of surface coatings of high gloss and standard uncoated papers for sheet-fed printing. During the period of four months, changes in the mass of steel specimens were measured (loss of material, as well as changes in pH values and conductivity of the examined solutions. Formation of corrosion products on the surface was identified by changes of spectrophotometric reemission in the visible portion of the steel spectrum and by FT-IR spectral recordings. In addition, the electrochemical potentiodynamic measurements were carried out with the direct current and the method of linear polarization and Tafel’s extrapolation, by which the corrosion parameters were determined: corrosion potential, corrosion current density, polarization resistance cathodic and anodic inclination of Tafel’s lines, as well as the corrosion rate. The results show that the dynamics of the corrosion in printing machines is directly influenced by the type of the paper used for printing. This investigation gave an insight into dynamics and mechanisms of corrosion under conditions close to those in printing production, thus facilitating better understanding of the entire process.

  17. Research on automatic inspection system for defects on precise optical surface based on machine vision

    Institute of Scientific and Technical Information of China (English)

    WANG Xue; XIE Zhi-jiang

    2006-01-01

    In manufacture of precise optical products, it is important to inspect and classify the potential defects existing on the products' surfaces after precise machining in order to obtain high quality in both functionality and aesthetics. The existing methods for detecting and classifying defects all are low accuracy or efficiency or high cost in inspection process. In this paper, a new inspection system based on machine vision has been introduced, which uses automatic focusing and image mosaic technologies to rapidly acquire distinct surface image, and employs Case-Based Reasoning(CBR)method in defects classification. A modificatory fuzzy similarity algorithm in CBR has been adopted for more quick and robust need of pattern recognition in practice inspection. Experiments show that the system can inspect surface diameter of 500mm in half an hour with resolving power of 0.8μm diameter according to digs or 0.5μm transverse width according to scratches. The proposed inspection principles and methods not only have meet manufacturing requirements of precise optical products, but also have great potential applications in other fields of precise surface inspection.

  18. A Machine Vision System for Quality Inspection of Pine Nuts

    Directory of Open Access Journals (Sweden)

    Ikramullah Khosa

    2016-09-01

    Full Text Available Computers and artificial intelligence have penetrated in the food industry since last decade, for intellectual automatic processing and packaging in general, and in assisting for quality inspection of the food itself in particular. The food quality assessment task becomes more challenging when it is about harmless internal examination of the ingredient, and even more when its size is also minute. In this article, a method for automatic detection, extraction and classification of raw food item is presented using x-ray image data of pine nuts. Image processing techniques are employed in developing an efficient method for automatic detection and then extraction of individual ingredient, from the source x-ray image which comprises bunch of nuts in a single frame. For data representation, statistical texture analysis is carried out and attributes are calculated from each of the sample image on the global level as features. In addition co-occurrence matrices are computed from images with four different offsets, and hence more features are extracted by using them. To find fewer meaningful characteristics, all the calculated features are organized in several combinations and then tested. Seventy percent of image data is used for training and 15% each for cross-validation and test purposes. Binary classification is performed using two state-of-the-art non-linear classifiers: Artificial Neural Network (ANN and Support Vector Machines (SVM. Performance is evaluated in terms of classification accuracy, specificity and sensitivity. ANN classifier showed 87.6% accuracy with correct recognition rate of healthy nuts and unhealthy nuts as 94% and 62% respectively. SVM classifier produced the similar accuracy achieving 86.3% specificity and 89.2% sensitivity rate. The results obtained are unique itself in terms of ingredient and promising relatively. It is also found that feature set size can be reduced up to 57% by compromising 3.5% accuracy, in combination with

  19. The characteristics of machined surface controlled by multi tip arrayed tool and high speed spindle.

    Science.gov (United States)

    Kim, Yong Woo; Choi, Soo Chang; Park, Jeong Woo; Lee, Deug Woo

    2010-07-01

    In this study, we propose one of the ultra-precision machining methods that can be adapted brittle material as well as soft material by using multi arrayed diamond tips and high speed spindle. Conventional machining method is too hard to control surface roughness and surface texture against brittle material because particles of grinding tools are irregular size and material can be fragile. Therefore we were able to design tool paths and machine controlled pattern on surface by multi arrayed diamond tips which has uniform size made in MEMS fabrication and high speed spindle of which maximum speed is about 300,000 rpm. We defined several parameters that can have effect on machining surface. Those are multi array of diamond tips (n * n), speed of the air spindle, and feeding rate. Surface roughness and surface texture can be controlled by those parameters for micro machining.

  20. Quality of silicon convex lenses fabricated by ultra-high precision diamond machining

    Directory of Open Access Journals (Sweden)

    Abou-El-Hossein, K.

    2013-05-01

    Full Text Available Infra-red optical components are made mainly from hard and brittle materials such as germanium and silicon. Silicon machining is characterised by some difficulties when ultra-high precision machined by mono-crystalline single-point diamond. Accelerated tool wear and machined-surface deterioration may take place if the machining parameters are not properly selected. In this study, we conducted a machining test on an ultra-high precision machine tool, using ductile regime cutting conditions when fabricating a convex surface on a silicon lens of aperture of 60 mm diameter, and using a mono-crystalline diamond. It was found that the cutting conditions for shaping a convex surface of 500 mm radius resulted in good form accuracy. However, more attention should be paid to optimising the holding force of the vacuum chuck employed.

  1. An investigation on surface roughness of granite machined by abrasive waterjet

    Indian Academy of Sciences (India)

    Gokhan Aydin; Izzet Karakurt; Kerim Aydiner

    2011-07-01

    Abrasive waterjet (AWJ) cutting is an emerging technology which enables the shaping of practically all engineering materials. However, AWJ cutting may cause roughness and waviness on the cut surface. This significantly affects the dimensional accuracy of the machined part and the quality of surface finish. In this study, the surface roughness of three granites is experimentally investigated for varying process parameters in abrasive waterjet. The philosophy of the Taguchi design is followed in the experimental study. Effects of the control (process) factors on the surface roughness are presented in terms of the mean of means responses. Additionally, the data obtained are evaluated statistically using the analysis of variance (ANOVA) to determine significant process parameters affecting the surface roughness. Furthermore, effects of the material properties on the surface roughness are assessed. It was statistically found that the water pressure and the abrasive flow rate are the most significant factors influencing the surface roughness of granites. Additionally, a consistent relationship between the material grain size and surface roughness of the granites was observed.

  2. An Evaluation of Output Quality of Machine Translation (Padideh Software vs. Google Translate

    Directory of Open Access Journals (Sweden)

    Haniyeh Sadeghi Azer

    2015-08-01

    Full Text Available This study aims to evaluate the translation quality of two machine translation systems in translating six different text-types, from English to Persian. The evaluation was based on criteria proposed by Van Slype (1979. The proposed model for evaluation is a black-box type, comparative and adequacy-oriented evaluation. To conduct the evaluation, a questionnaire was assigned to end-users to evaluate the outputs to examine and determine, if the machine-generated translations are intelligible and acceptable from their point of view and which one of the machine-generated translations produced by Padideh software and Google Translate is more acceptable and useful from the end-users point of view. The findings indicate that, the machine-generated translations are intelligible and acceptable in translating certain text-types, for end-users and Google Translate is more acceptable from end-users point of view. Keywords: Machine Translation, Machine Translation Evaluation, Translation Quality

  3. Improvement of machining quality of copper-plated roll mold by controlling temperature variation

    Institute of Scientific and Technical Information of China (English)

    Tae-Jin JE; Eun-Chae JEON; Sang-Cheon PARK; Doo-Sun CHOI; Kyung-Hyun WHANG; Myung-Chang KANG

    2011-01-01

    Micro prism film used in LCD industry can be manufactured by roll to roll method with copper-plated roll mold. As copper-plated roll mold is getting larger, pitch error is getting severer. The pitch error drops the quality of micro prism film. The main cause of the pitch error was investigated during machining large roll mold whose machined length was 1 200 mm. The temperature of machining system was elevated during machining roll mold, and this elevation induced thermal expansion of the system. The temperature variation around the roll mold also made thermal expansion of the roll mold. The amount of thermal expansion had strong relationship to the amount of pitch error. Therefore, the roll mold was machined after warming-up of machining system and precise temperature controller around copper-plated roll mold was installed, which minimized the temperature variation. Finally,precise micro prism patterns without pitch error were machined on the large roll mold.

  4. Effect of machining parameters on surface finish of Inconel 718 in end milling

    Directory of Open Access Journals (Sweden)

    Sarkar Bapi

    2017-01-01

    Full Text Available Surface finish is an important criteria in machining process and selection of proper machining parameters is important to obtain good surface finish. In the present work effects of the machining parameters in end milling of Inconel 718 were investigated. Central composite design was used to design the total number of experiments. A Mathematical model for surface roughness has been developed using response surface methodology. In this study, the influence of cutting parameters such as cutting speed, feed rate and depth of cut on surface roughness was analyzed. The study includes individual effect of cutting parameters on surface roughness as well as their interaction. The analysis of variance (ANOVA was employed to find the validity of the developed model. The results show that depth of cut mostly affected the surface roughness. It is also observed that surface roughness values are comparable in both dry and wet machining conditions.

  5. Forecasting of Machined Surface Waviness on the Basis of Self-oscillations Analysis

    Science.gov (United States)

    Belov, E. B.; Leonov, S. L.; Markov, A. M.; Sitnikov, A. A.; Khomenko, V. A.

    2017-01-01

    The paper states a problem of providing quality of geometrical characteristics of machined surfaces, which makes it necessary to forecast the occurrence and amount of oscillations appearing in the course of mechanical treatment. Objectives and tasks of the research are formulated. Sources of oscillation onset are defined: these are coordinate connections and nonlinear dependence of cutting force on the cutting velocity. A mathematical model of forecasting steady-state self-oscillations is investigated. The equation of the cutter tip motion is a system of two second-order nonlinear differential equations. The paper shows an algorithm describing a harmonic linearization method which allows for a significant reduction of the calculation time. In order to do that it is necessary to determine the amplitude of oscillations, frequency and a steady component of the first harmonic. Software which allows obtaining data on surface waviness parameters is described. The paper studies an example of the use of the developed model in semi-finished lathe machining of the shaft made from steel 40H which is a part of the BelAZ wheel electric actuator unit. Recommendations on eliminating self-oscillations in the process of shaft cutting and defect correction of the surface waviness are given.

  6. Burnishing of rotatory parts to improve surface quality

    Science.gov (United States)

    Celaya, A.; López de Lacalle, L. N.; Albizuri, J.; Alberdi, R.

    2009-11-01

    In this paper, the use of rolling burnishing process to improve the final quality of railway and automotive workpieces is studied. The results are focused on the improvement of the manufacturing processes of rotary workpieces used in railway and automotion industry, attending to generic target of achieving `maximum surface quality with minimal process time'. Burnishing is a finishing operation in which plastic deformation of surface irregularities occurs by applying pressure through a very hard element, a roller or a ceramic ball. This process gives additional advantages to the workpiece such as good surface roughness, increased hardness and high compressive residual stresses. The effect of the initial turning conditions on the final burnishing operation has also been studied. The results show that feeds used in the initial rough turning have little influence in the surface finish of the burnished workpieces. So, the process times of the combined turning and burnishing processes can be reduced, optimizing the shaft's machining process.

  7. Coastal water quality estimation from Geostationary Ocean Color Imager (GOCI) satellite data using machine learning approaches

    Science.gov (United States)

    Im, Jungho; Ha, Sunghyun; Kim, Yong Hoon; Ha, Hokyung; Choi, Jongkuk; Kim, Miae

    2014-05-01

    It is important to monitor coastal water quality using key parameters such as chlorophyll-a concentration and suspended sediment to better manage coastal areas as well as to better understand the nature of biophysical processes in coastal seawater. Remote sensing technology has been commonly used to monitor coastal water quality due to its ability of covering vast areas at high temporal resolution. While it is relatively straightforward to estimate water quality in open ocean (i.e., Case I water) using remote sensing, coastal water quality estimation is still challenging as many factors can influence water quality, including various materials coming from inland water systems and tidal circulation. There are continued efforts to accurately estimate water quality parameters in coastal seawater from remote sensing data in a timely manner. In this study, two major water quality indicators, chlorophyll-a concentration and the amount of suspended sediment, were estimated using Geostationary Ocean Color Imager (GOCI) satellite data. GOCI, launched in June 2010, is the first geostationary ocean color observation satellite in the world. GOCI collects data hourly for 8 hours a day at 6 visible and 2 near-infrared bands at a 500 m resolution with 2,500 x 2,500 km square around Korean peninsula. Along with conventional statistical methods (i.e., various linear and non-linear regression), three machine learning approaches such as random forest, Cubist, and support vector regression were evaluated for coastal water quality estimation. In situ measurements (63 samples; including location, two water quality parameters, and the spectra of surface water using a hand-held spectroradiometer) collected during four days between 2011 and 2012 were used as reference data. Due to the small sample size, leave-one-out cross validation was used to assess the performance of the water quality estimation models. Atmospherically corrected radiance data and selected band-ratioed images were used

  8. A novel approach to predict surface roughness in machining operations using fuzzy set theory

    Directory of Open Access Journals (Sweden)

    Tzu-Liang (Bill Tseng

    2016-01-01

    Full Text Available The increase of consumer needs for quality metal cutting related products with more precise tolerances and better product surface roughness has driven the metal cutting industry to continuously improve quality control of metal cutting processes. In this paper, two different approaches are discussed. First, design of experiments (DOE is used to determine the significant factors and then fuzzy logic approach is presented for the prediction of surface roughness. The data used for the training and checking the fuzzy logic performance is derived from the experiments conducted on a CNC milling machine. In order to obtain better surface roughness, the proper sets of cutting parameters are determined before the process takes place. The factors considered for DOE in the experiment were the depth of cut, feed rate per tooth, cutting speed, tool nose radius, the use of cutting fluid and the three components of the cutting force. Finally the significant factors were used as input factors for fuzzy logic mechanism and surface roughness is predicted with empirical formula developed. Test results show good agreement between the actual process output and the predicted surface roughness.

  9. Word Transition Entropy as an Indicator for Expected Machine Translation Quality

    DEFF Research Database (Denmark)

    Carl, Michael; Schaeffer, Moritz

    2014-01-01

    While most machine translation evaluation techniques (BLEU, NIST, TER, METEOR) assess translation quality based on a set of reference translations, we suggest to evaluate the literality of a set of (human or machine generated) translations to infer their potential quality. We provide evidence which...... suggests that more literal translations are produced more easily, by humans and machine, and are also less error prone. Literal translations may not be appropriate or even possible for all languages, types of texts, and translation purposes. However, in this paper we show that an assessment...... of the literality of translations allows us to (1) evaluate human and machine translations in a similar fashion and (2) may be instrumental to predict machine translation quality scores,...

  10. A real-time surface inspection system for precision steel balls based on machine vision

    Science.gov (United States)

    Chen, Yi-Ji; Tsai, Jhy-Cherng; Hsu, Ya-Chen

    2016-07-01

    Precision steel balls are one of the most fundament components for motion and power transmission parts and they are widely used in industrial machinery and the automotive industry. As precision balls are crucial for the quality of these products, there is an urgent need to develop a fast and robust system for inspecting defects of precision steel balls. In this paper, a real-time system for inspecting surface defects of precision steel balls is developed based on machine vision. The developed system integrates a dual-lighting system, an unfolding mechanism and inspection algorithms for real-time signal processing and defect detection. The developed system is tested under feeding speeds of 4 pcs s-1 with a detection rate of 99.94% and an error rate of 0.10%. The minimum detectable surface flaw area is 0.01 mm2, which meets the requirement for inspecting ISO grade 100 precision steel balls.

  11. Pre-use anesthesia machine check; certified anesthesia technician based quality improvement audit

    Science.gov (United States)

    Al Suhaibani, Mazen; Al Malki, Assaf; Al Dosary, Saad; Al Barmawi, Hanan; Pogoku, Mahdhav

    2014-01-01

    Context: Quality assurance of providing a work ready machine in multiple theatre operating rooms in a tertiary modern medical center in Riyadh. Aims: The aim of the following study is to keep high quality environment for workers and patients in surgical operating rooms. Settings and Design: Technicians based audit by using key performance indicators to assure inspection, passing test of machine worthiness for use daily and in between cases and in case of unexpected failure to provide quick replacement by ready to use another anesthetic machine. Materials and Methods: The anesthetic machines in all operating rooms are daily and continuously inspected and passed as ready by technicians and verified by anesthesiologist consultant or assistant consultant. The daily records of each machines were collected then inspected for data analysis by quality improvement committee department for descriptive analysis and report the degree of staff compliance to daily inspection as “met” items. Replaced machine during use and overall compliance. Statistical Analysis Used: Distractive statistic using Microsoft Excel 2003 tables and graphs of sums and percentages of item studied in this audit. Results: Audit obtained highest compliance percentage and low rate of replacement of machine which indicate unexpected machine state of use and quick machine switch. Conclusions: The authors are able to conclude that following regular inspection and running self-check recommended by the manufacturers can contribute to abort any possibility of hazard of anesthesia machine failure during operation. Furthermore in case of unexpected reason to replace the anesthesia machine in quick maneuver contributes to high assured operative utilization of man machine inter-phase in modern surgical operating rooms. PMID:25886335

  12. Research on the effect of coverage rate on the surface quality in laser direct writing process

    Science.gov (United States)

    Pan, Xuetao; Tu, Dawei

    2017-07-01

    Direct writing technique is usually used in femtosecond laser two-photon micromachining. The size of the scanning step is an important factor affecting the surface quality and machining efficiency of micro devices. According to the mechanism of two-photon polymerization, combining the distribution function of light intensity and the free radical concentration theory, we establish the mathematical model of coverage of solidification unit, then analyze the effect of coverage on the machining quality and efficiency. Using the principle of exposure equivalence, we also obtained the analytic expressions of the relationship among the surface quality characteristic parameters of microdevices and the scanning step, and carried out the numerical simulation and experiment. The results show that the scanning step has little influence on the surface quality of the line when it is much smaller than the size of the solidification unit. However, with increasing scanning step, the smoothness of line surface is reduced rapidly, and the surface quality becomes much worse.

  13. Pre-use anesthesia machine check; certified anesthesia technician based quality improvement audit

    OpenAIRE

    2014-01-01

    Context: Quality assurance of providing a work ready machine in multiple theatre operating rooms in a tertiary modern medical center in Riyadh. Aims: The aim of the following study is to keep high quality environment for workers and patients in surgical operating rooms. Settings and Design: Technicians based audit by using key performance indicators to assure inspection, passing test of machine worthiness for use daily and in between cases and in case of unexpected failure to provide quick re...

  14. Machining of bone: Analysis of cutting force and surface roughness by turning process.

    Science.gov (United States)

    Noordin, M Y; Jiawkok, N; Ndaruhadi, P Y M W; Kurniawan, D

    2015-11-01

    There are millions of orthopedic surgeries and dental implantation procedures performed every year globally. Most of them involve machining of bones and cartilage. However, theoretical and analytical study on bone machining is lagging behind its practice and implementation. This study views bone machining as a machining process with bovine bone as the workpiece material. Turning process which makes the basis of the actually used drilling process was experimented. The focus is on evaluating the effects of three machining parameters, that is, cutting speed, feed, and depth of cut, to machining responses, that is, cutting forces and surface roughness resulted by the turning process. Response surface methodology was used to quantify the relation between the machining parameters and the machining responses. The turning process was done at various cutting speeds (29-156 m/min), depths of cut (0.03 -0.37 mm), and feeds (0.023-0.11 mm/rev). Empirical models of the resulted cutting force and surface roughness as the functions of cutting speed, depth of cut, and feed were developed. Observation using the developed empirical models found that within the range of machining parameters evaluated, the most influential machining parameter to the cutting force is depth of cut, followed by feed and cutting speed. The lowest cutting force was obtained at the lowest cutting speed, lowest depth of cut, and highest feed setting. For surface roughness, feed is the most significant machining condition, followed by cutting speed, and with depth of cut showed no effect. The finest surface finish was obtained at the lowest cutting speed and feed setting.

  15. Influence of Surface Position along the Working Range of Conoscopic Holography Sensors on Dimensional Verification of AISI 316 Wire EDM Machined Surfaces

    Directory of Open Access Journals (Sweden)

    Pedro Fernández

    2014-03-01

    Full Text Available Conoscopic holography (CH is a non-contact interferometric technique used for surface digitization which presents several advantages over other optical techniques such as laser triangulation. Among others, the ability for the reconstruction of high-sloped surfaces stands out, and so does its lower dependence on surface optical properties. Nevertheless, similarly to other optical systems, adjustment of CH sensors requires an adequate selection of configuration parameters for ensuring a high quality surface digitizing. This should be done on a surface located as close as possible to the stand-off distance by tuning frequency (F and power (P until the quality indicators Signal-to-Noise Ratio (SNR and signal envelope (Total meet proper values. However, not all the points of an actual surface are located at the stand-off distance, but they could be located throughout the whole working range (WR. Thus, the quality of a digitized surface may not be uniform. The present work analyses how the quality of a reconstructed surface is affected by its relative position within the WR under different combinations of the parameters F and P. Experiments have been conducted on AISI 316 wire EDM machined flat surfaces. The number of high-quality points digitized as well as distance measurements between different surfaces throughout the WR allowed for comparing the metrological behaviour of the CH sensor with respect to a touch probe (TP on a CMM.

  16. Multi-Parameter Analysis of Surface Finish in Electro-Discharge Machining of Tool Steels

    Directory of Open Access Journals (Sweden)

    Cornelia Victoria Anghel

    2006-10-01

    Full Text Available The paper presents a multi- parameter analysis of surface finish imparted to tool-steel plates by electro-discharge machining (EDM is presented. The interrelationship between surface texture parameters and process parameters is emphasized. An increased number of parameters is studied including amplitude, spacing, hybrid and fractal parameters,, as well. The correlation of these parameters with the machining conditions is investigated. Observed characteristics become more pronounced, when intensifying machining conditions. Close correlation exists between certain surface finish parameters and EDM input variables and single and multiple statistical regression models are developed.

  17. Planning machine paths and row crop patterns on steep surfaces to minimize soil erosion

    NARCIS (Netherlands)

    Spekken, Mark; Bruin, De Sytze; Molin, José Paulo; Sparovek, Gerd

    2016-01-01

    Soil erosion in arable fields is intensified on irregular surfaces. Although machine and crop-row patterns following terrain contours reduce runoff and increase water infiltration, these contours are almost never parallel while machine operations always are. In this work, a method is presented to

  18. Machine vision method for online surface inspection of easy open can ends

    Science.gov (United States)

    Mariño, Perfecto; Pastoriza, Vicente; Santamaría, Miguel

    2006-10-01

    Easy open can end manufacturing process in the food canning sector currently makes use of a manual, non-destructive testing procedure to guarantee can end repair coating quality. This surface inspection is based on a visual inspection made by human inspectors. Due to the high production rate (100 to 500 ends per minute) only a small part of each lot is verified (statistical sampling), then an automatic, online, inspection system, based on machine vision, has been developed to improve this quality control. The inspection system uses a fuzzy model to make the acceptance/rejection decision for each can end from the information obtained by the vision sensor. In this work, the inspection method is presented. This surface inspection system checks the total production, classifies the ends in agreement with an expert human inspector, supplies interpretability to the operators in order to find out the failure causes and reduce mean time to repair during failures, and allows to modify the minimum can end repair coating quality.

  19. Optimization of Surface Finish in Turning Operation by Considering the Machine Tool Vibration using Taguchi Method

    Directory of Open Access Journals (Sweden)

    Muhammad Munawar

    2012-01-01

    Full Text Available Optimization of surface roughness has been one of the primary objectives in most of the machining operations. Poor control on the desired surface roughness generates non conforming parts and results into increase in cost and loss of productivity due to rework or scrap. Surface roughness value is a result of several process variables among which machine tool condition is one of the significant variables. In this study, experimentation was carried out to investigate the effect of machine tool condition on surface roughness. Variable used to represent machine tool\\'s condition was vibration amplitude. Input parameters used, besides vibration amplitude, were feed rate and insert nose radius. Cutting speed and depth of cut were kept constant. Based on Taguchi orthogonal array, a series of experimentation was designed and performed on AISI 1040 carbon steel bar at default and induced machine tool\\'s vibration amplitudes. ANOVA (Analysis of Variance, revealed that vibration amplitude and feed rate had moderate effect on the surface roughness and insert nose radius had the highest significant effect on the surface roughness. It was also found that a machine tool with low vibration amplitude produced better surface roughness. Insert with larger nose radius produced better surface roughness at low feed rate.

  20. Effects of cutting parameters and machining environments on surface roughness in hard turning using design of experiment

    Science.gov (United States)

    Mia, Mozammel; Bashir, Mahmood Al; Dhar, Nikhil Ranjan

    2016-07-01

    Hard turning is gradually replacing the time consuming conventional turning process, which is typically followed by grinding, by producing surface quality compatible to grinding. The hard turned surface roughness depends on the cutting parameters, machining environments and tool insert configurations. In this article the variation of the surface roughness of the produced surfaces with the changes in tool insert configuration, use of coolant and different cutting parameters (cutting speed, feed rate) has been investigated. This investigation was performed in machining AISI 1060 steel, hardened to 56 HRC by heat treatment, using coated carbide inserts under two different machining environments. The depth of cut, fluid pressure and material hardness were kept constant. The Design of Experiment (DOE) was performed to determine the number and combination sets of different cutting parameters. A full factorial analysis has been performed to examine the effect of main factors as well as interaction effect of factors on surface roughness. A statistical analysis of variance (ANOVA) was employed to determine the combined effect of cutting parameters, environment and tool configuration. The result of this analysis reveals that environment has the most significant impact on surface roughness followed by feed rate and tool configuration respectively.

  1. Redesigned Surface Based Machining Strategy and Method in Peripheral Milling of Thin-walled Parts

    Institute of Scientific and Technical Information of China (English)

    JIA Zhenyuan; GUO Qiang; SUN Yuwen; GUO Dongming

    2010-01-01

    Currently, simultaneously ensuring the machining accuracy and efficiency of thin-walled structures especially high performance parts still remains a challenge. Existing compensating methods are mainly focusing on 3-aixs machining, which sometimes only take one given point as the compensative point at each given cutter location. This paper presents a redesigned surface based machining strategy for peripheral milling of thin-walled parts. Based on an improved cutting force/heat model and finite element method(FEM) simulation environment, a deflection error prediction model, which takes sequence of cutter contact lines as compensation targets, is established. And an iterative algorithm is presented to determine feasible cutter axis positions. The final redesigned surface is subsequently generated by skinning all discrete cutter axis vectors after compensating by using the proposed algorithm. The proposed machining strategy incorporates the thermo-mechanical coupled effect in deflection prediction, and is also validated with flank milling experiment by using five-axis machine tool. At the same time, the deformation error is detected by using three-coordinate measuring machine. Error prediction values and experimental results indicate that they have a good consistency and the proposed approach is able to significantly reduce the dimension error under the same machining conditions compared with conventional methods. The proposed machining strategy has potential in high-efficiency precision machining of thin-walled parts.

  2. Artificial Molecular Machine Immobilized Surfaces: A New Platform To Construct Functional Materials.

    Science.gov (United States)

    Zhang, Qi; Qu, Da-Hui

    2016-06-17

    Artificial molecular machines have received significant attention from chemists because of their unique ability to mimic the behaviors of biological systems. Artificial molecular machines can be easily modified with functional groups to construct new types of functional molecular switches. However, practical applications of artificial molecular machines are still challenging, because the working platform of artificial molecular machines is mostly in solution. Artificial molecular machine immobilized surfaces (AMMISs) are considered a promising platform to construct functional materials. Herein, we provide a minireview of some recent advances of functional AMMISs. The functions of AMMISs are highlighted and strategies for their construction are also discussed. Furthermore, a brief perspective of the development of artificial molecular machines towards functional materials is given.

  3. Influence of Combined Hard and Fine Machining on the Surface Properties of Cemented Carbides

    Directory of Open Access Journals (Sweden)

    U. Engel

    2012-09-01

    Full Text Available As a result of recent developments in cold forging cemented carbides are increasingly used as tool materials. Due to their high hardness only electrical discharge machining (EDM and grinding are suitable for tool machining. The structure of tool surface has significant influence on dominating failure mechanisms wear and fatigue. For improvement of tribological conditions the surface is polished in a finale processing step. The result of hard and fine machining is a specific combination of coarse and fine structure which is determined by processing parameters. The different surface structures lead to a particular tool behavior in forming process. This paper aims to show the influence of combined hard and fine machining on the surface properties of cemented carbides.

  4. Prediction of the Functional Performance of Machined Components Based on Surface Topography: State of the Art

    Science.gov (United States)

    Grzesik, Wit

    2016-10-01

    This survey overviews the functional performance of manufactured components produced by typical finishing machining operations in terms of their topographical characteristics. Surface topographies were characterized using both profile (2D) and 3D (areal) surface roughness parameters. The prediction of typical functional properties such as fatigue, friction, wear, bonding and corrosion is discussed based on appropriate surface roughness parameters. Some examples of real 3D surface topographies produced with desired functional characteristics are provided. This survey highlights technological possibilities of producing surfaces with enhanced functional properties by machining processes.

  5. Surface Modification Process by Electrical Discharge Machining with Ti Powder Green Compact Electrode

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    This paper describes a new method of surface modification by Electrical Discharge Machining (EDM). By using ordinary EDM machine tool and kerosene fluid, a hard ceramic layer can be created on the workpiece surface with Ti or other compressed powder electrode in a certain condition. This new revolutionary method is called Electrical Discharge Coating (EDC). The process of EDC begins with electrode wear during EDM,then a kind of hard carbide is created through the thermal and chemical reaction between the wo...

  6. Shaping of steel mold surface of lens array by electrical discharge machining with single rod electrode.

    Science.gov (United States)

    Takino, Hideo; Hosaka, Takahiro

    2014-11-20

    We propose a method for fabricating a lens array mold by electrical discharge machining (EDM). In this method, the tips of rods are machined individually to form a specific surface, and then a number of the machined rods are arranged to construct an electrode for EDM. The repetition of the EDM process using the electrode enables a number of lens elements to be produced on the mold surface. The effectiveness of our proposed method is demonstrated by shaping a lens array mold made of stainless steel with 16 spherical elements, in which the EDM process with a single rod electrode is repeatedly conducted.

  7. A comparative study of surface EMG classification by fuzzy relevance vector machine and fuzzy support vector machine.

    Science.gov (United States)

    Xie, Hong-Bo; Huang, Hu; Wu, Jianhua; Liu, Lei

    2015-02-01

    We present a multiclass fuzzy relevance vector machine (FRVM) learning mechanism and evaluate its performance to classify multiple hand motions using surface electromyographic (sEMG) signals. The relevance vector machine (RVM) is a sparse Bayesian kernel method which avoids some limitations of the support vector machine (SVM). However, RVM still suffers the difficulty of possible unclassifiable regions in multiclass problems. We propose two fuzzy membership function-based FRVM algorithms to solve such problems, based on experiments conducted on seven healthy subjects and two amputees with six hand motions. Two feature sets, namely, AR model coefficients and room mean square value (AR-RMS), and wavelet transform (WT) features, are extracted from the recorded sEMG signals. Fuzzy support vector machine (FSVM) analysis was also conducted for wide comparison in terms of accuracy, sparsity, training and testing time, as well as the effect of training sample sizes. FRVM yielded comparable classification accuracy with dramatically fewer support vectors in comparison with FSVM. Furthermore, the processing delay of FRVM was much less than that of FSVM, whilst training time of FSVM much faster than FRVM. The results indicate that FRVM classifier trained using sufficient samples can achieve comparable generalization capability as FSVM with significant sparsity in multi-channel sEMG classification, which is more suitable for sEMG-based real-time control applications.

  8. Response surface and artificial neural network prediction model and optimization for surface roughness in machining

    Directory of Open Access Journals (Sweden)

    Ashok Kumar Sahoo

    2015-04-01

    Full Text Available The present paper deals with the development of prediction model using response surface methodology and artificial neural network and optimizes the process parameter using 3D surface plot. The experiment has been conducted using coated carbide insert in machining AISI 1040 steel under dry environment. The coefficient of determination value for RSM model is found to be high (R2 = 0.99 close to unity. It indicates the goodness of fit for the model and high significance of the model. The percentage of error for RSM model is found to be only from -2.63 to 2.47. The maximum error between ANN model and experimental lies between -1.27 and 0.02 %, which is significantly less than the RSM model. Hence, both the proposed RSM and ANN prediction model sufficiently predict the surface roughness, accurately. However, ANN prediction model seems to be better compared with RSM model. From the 3D surface plots, the optimal parametric combination for the lowest surface roughness is d1-f1-v3 i.e. depth of cut of 0.1 mm, feed of 0.04 mm/rev and cutting speed of 260 m/min respectively.

  9. Surface Finish and Residual Stresses Induced by Orthogonal Dry Machining of AA7075-T651.

    Science.gov (United States)

    Jomaa, Walid; Songmene, Victor; Bocher, Philippe

    2014-02-28

    The surface finish was extensively studied in usual machining processes (turning, milling, and drilling). For these processes, the surface finish is strongly influenced by the cutting feed and the tool nose radius. However, a basic understanding of tool/surface finish interaction and residual stress generation has been lacking. This paper aims to investigate the surface finish and residual stresses under the orthogonal cutting since it can provide this information by avoiding the effect of the tool nose radius. The orthogonal machining of AA7075-T651 alloy through a series of cutting experiments was performed under dry conditions. Surface finish was studied using height and amplitude distribution roughness parameters. SEM and EDS were used to analyze surface damage and built-up edge (BUE) formation. An analysis of the surface topography showed that the surface roughness was sensitive to changes in cutting parameters. It was found that the formation of BUE and the interaction between the tool edge and the iron-rich intermetallic particles play a determinant role in controlling the surface finish during dry orthogonal machining of the AA7075-T651 alloy. Hoop stress was predominantly compressive on the surface and tended to be tensile with increased cutting speed. The reverse occurred for the surface axial stress. The smaller the cutting feed, the greater is the effect of cutting speed on both axial and hoop stresses. By controlling the cutting speed and feed, it is possible to generate a benchmark residual stress state and good surface finish using dry machining.

  10. The evolution of machining-induced surface of single-crystal FCC copper via nanoindentation.

    Science.gov (United States)

    Zhang, Lin; Huang, Hu; Zhao, Hongwei; Ma, Zhichao; Yang, Yihan; Hu, Xiaoli

    2013-05-04

    The physical properties of the machining-induced new surface depend on the performance of the initial defect surface and deformed layer in the subsurface of the bulk material. In this paper, three-dimensional molecular dynamics simulations of nanoindentation are preformed on the single-point diamond turning surface of single-crystal copper comparing with that of pristine single-crystal face-centered cubic copper. The simulation results indicate that the nucleation of dislocations in the nanoindentation test on the machining-induced surface and pristine single-crystal copper is different. The dislocation embryos are gradually developed from the sites of homogeneous random nucleation around the indenter in the pristine single-crystal specimen, while the dislocation embryos derived from the vacancy-related defects are distributed in the damage layer of the subsurface beneath the machining-induced surface. The results show that the hardness of the machining-induced surface is softer than that of pristine single-crystal copper. Then, the nanocutting simulations are performed along different crystal orientations on the same crystal surface. It is shown that the crystal orientation directly influences the dislocation formation and distribution of the machining-induced surface. The crystal orientation of nanocutting is further verified to affect both residual defect generations and their propagation directions which are important in assessing the change of mechanical properties, such as hardness and Young's modulus, after nanocutting process.

  11. On Machine Capacitance Dimensional and Surface Profile Measurement System

    Science.gov (United States)

    Resnick, Ralph

    1993-01-01

    A program was awarded under the Air Force Machine Tool Sensor Improvements Program Research and Development Announcement to develop and demonstrate the use of a Capacitance Sensor System including Capacitive Non-Contact Analog Probe and a Capacitive Array Dimensional Measurement System to check the dimensions of complex shapes and contours on a machine tool or in an automated inspection cell. The manufacturing of complex shapes and contours and the subsequent verification of those manufactured shapes is fundamental and widespread throughout industry. The critical profile of a gear tooth; the overall shape of a graphite EDM electrode; the contour of a turbine blade in a jet engine; and countless other components in varied applications possess complex shapes that require detailed and complex inspection procedures. Current inspection methods for complex shapes and contours are expensive, time-consuming, and labor intensive.

  12. The impact of breaks during foundry work of the pressure casting machine on casting quality

    Directory of Open Access Journals (Sweden)

    S. Borkowski

    2010-10-01

    Full Text Available The result in the appearance of the technical object damage are its failures, which are considered as the most important causes of productivity loss in the technical objects. The article introduces main types of losses resulting from the downtimes of a casting machine. The time impact analysis of the font mould failure and the remaining time of the machine's failures on the castings quality was conducted. The failure time structure of the font mould and other failures of the machine was presented.

  13. High Quality Fixture Quenching Fixture Types, Levels of Automation and Machine Types

    Institute of Scientific and Technical Information of China (English)

    STRENG; Th.,HEESS,K.; MUELLER-LAESSIG, G.

    2004-01-01

    The paper shows, how the quality of workpieces to be heat treated can be improved by using the technology of fixture-quenching. Different fixture systems, like fixed mandrel, expanding mandrel and lamellar mandrel are described. In the next section there is a comparison between manual operation of hardening machines vs. automated lines. Since there are applications for each, manual and fully automated hardening systems, HEESS has not only focused to develop automated lines, but also refined manual operated hardening machines (SP-Series). These take advantage of the latest technology, like for example quick tool change and PLC-control with workpiece parameter database. An overview over different machine types is given.

  14. Method and apparatus for improving the quality and efficiency of ultrashort-pulse laser machining

    Science.gov (United States)

    Stuart, Brent C.; Nguyen, Hoang T.; Perry, Michael D.

    2001-01-01

    A method and apparatus for improving the quality and efficiency of machining of materials with laser pulse durations shorter than 100 picoseconds by orienting and maintaining the polarization of the laser light such that the electric field vector is perpendicular relative to the edges of the material being processed. Its use is any machining operation requiring remote delivery and/or high precision with minimal collateral dames.

  15. Prediction of material removal rate and surface roughness for wire electrical discharge machining of nickel using response surface methodology

    Directory of Open Access Journals (Sweden)

    Thangam Chinnadurai

    2016-12-01

    Full Text Available This study focuses on investigating the effects of process parameters, namely, Peak current (Ip, Pulse on time (Ton, Pulse off time (Toff, Water pressure (Wp, Wire feed rate (Wf, Wire tension (Wt, Servo voltage (Sv and Servo feed setting (Sfs, on the Material Removal Rate (MRR and Surface Roughness (SR for Wire electrical discharge machining (Wire-EDM of nickel using Taguchi method. Response Surface Methodology (RSM is adopted to evolve mathematical relationships between the wire cutting process parameters and the output variables of the weld joint to determine the welding input parameters that lead to the desired optimal wire cutting quality. Besides, using response surface plots, the interaction effects of process parameters on the responses are analyzed and discussed. The statistical software Mini-tab is used to establish the design and to obtain the regression equations. The developed mathematical models are tested by analysis-of-variance (ANOVA method to check their appropriateness and suitability. Finally, a comparison is made between measured and calculated results, which are in good agreement. This indicates that the developed models can predict the responses accurately and precisely within the limits of cutting parameter being used.

  16. Precise on-machine extraction of the surface normal vector using an eddy current sensor array

    Science.gov (United States)

    Wang, Yongqing; Lian, Meng; Liu, Haibo; Ying, Yangwei; Sheng, Xianjun

    2016-11-01

    To satisfy the requirements of on-machine measurement of the surface normal during complex surface manufacturing, a highly robust normal vector extraction method using an Eddy current (EC) displacement sensor array is developed, the output of which is almost unaffected by surface brightness, machining coolant and environmental noise. A precise normal vector extraction model based on a triangular-distributed EC sensor array is first established. Calibration of the effects of object surface inclination and coupling interference on measurement results, and the relative position of EC sensors, is involved. A novel apparatus employing three EC sensors and a force transducer was designed, which can be easily integrated into the computer numerical control (CNC) machine tool spindle and/or robot terminal execution. Finally, to test the validity and practicability of the proposed method, typical experiments were conducted with specified testing pieces using the developed approach and system, such as an inclined plane and cylindrical and spherical surfaces.

  17. Design and Application of a Solar Mobile Pond Aquaculture Water Quality-Regulation Machine Based in Bream Pond Aquaculture.

    Directory of Open Access Journals (Sweden)

    Xingguo Liu

    Full Text Available Bream pond aquaculture plays a very important role in China's aquaculture industry and is the main source of aquatic products. To regulate and control pond water quality and sediment, a movable solar pond aquaculture water quality regulation machine (SMWM was designed and used. This machine is solar-powered and moves on water, and its primary components are a solar power supply device, a sediment lifting device, a mechanism for walking on the water's surface and a control system. The solar power supply device provides power for the machine, and the water walking mechanism drives the machine's motion on the water. The sediment lifting device orbits the main section of the machine and affects a large area of the pond. Tests of the machine's mechanical properties revealed that the minimum illumination necessary for the SMWM to function is 13,000 Lx and that its stable speed on the water is 0.02-0.03 m/s. For an illumination of 13,000-52,500 Lx, the sediment lifting device runs at 0.13-0.35 m/s, and its water delivery capacity is 110-208 m(3/h. The sediment lifting device is able to fold away, and the angle of the suction chamber can be adjusted, making the machine work well in ponds at different water depths from 0.5 m to 2 m. The optimal distance from the sediment lifting device to the bottom of the pond is 10-15 cm. In addition, adjusting the length of the connecting rod and the direction of the traction rope allows the SMWM to work in a pond water area greater than 80%. The analysis of water quality in Wuchang bream (Parabramis pekinensis and silver carp (Hypophthalmichthys molitrix culture ponds using the SMWM resulted in decreased NH3(+-N and available phosphorus concentrations and increased TP concentrations. The TN content and the amount of available phosphorus in the sediment were reduced. In addition, the fish production showed that the SMWM enhanced the yields of Wuchang bream and silver carp by more than 30% and 24%, respectively. These

  18. Design and Application of a Solar Mobile Pond Aquaculture Water Quality-Regulation Machine Based in Bream Pond Aquaculture.

    Science.gov (United States)

    Liu, Xingguo; Xu, Hao; Ma, Zhuojun; Zhang, Yongjun; Tian, Changfeng; Cheng, Guofeng; Zou, Haisheng; Lu, Shimin; Liu, Shijing; Tang, Rong

    2016-01-01

    Bream pond aquaculture plays a very important role in China's aquaculture industry and is the main source of aquatic products. To regulate and control pond water quality and sediment, a movable solar pond aquaculture water quality regulation machine (SMWM) was designed and used. This machine is solar-powered and moves on water, and its primary components are a solar power supply device, a sediment lifting device, a mechanism for walking on the water's surface and a control system. The solar power supply device provides power for the machine, and the water walking mechanism drives the machine's motion on the water. The sediment lifting device orbits the main section of the machine and affects a large area of the pond. Tests of the machine's mechanical properties revealed that the minimum illumination necessary for the SMWM to function is 13,000 Lx and that its stable speed on the water is 0.02-0.03 m/s. For an illumination of 13,000-52,500 Lx, the sediment lifting device runs at 0.13-0.35 m/s, and its water delivery capacity is 110-208 m(3)/h. The sediment lifting device is able to fold away, and the angle of the suction chamber can be adjusted, making the machine work well in ponds at different water depths from 0.5 m to 2 m. The optimal distance from the sediment lifting device to the bottom of the pond is 10-15 cm. In addition, adjusting the length of the connecting rod and the direction of the traction rope allows the SMWM to work in a pond water area greater than 80%. The analysis of water quality in Wuchang bream (Parabramis pekinensis) and silver carp (Hypophthalmichthys molitrix) culture ponds using the SMWM resulted in decreased NH3(+)-N and available phosphorus concentrations and increased TP concentrations. The TN content and the amount of available phosphorus in the sediment were reduced. In addition, the fish production showed that the SMWM enhanced the yields of Wuchang bream and silver carp by more than 30% and 24%, respectively. These results

  19. A Method for Identification and Compensation of Machining Errors of Digital Gear Tooth Surfaces

    Institute of Scientific and Technical Information of China (English)

    WANG Fulin; YI Chuanyun; CHEN Jing; YANG Shuzi

    2006-01-01

    In order to generate the digital gear tooth surfaces (DGTS) with high efficiency and high precision, a method for identification and compensation of machining errors is demonstrated in this paper. Machining errors are analyzed directly from the real tooth surfaces. The topography data of the part are off-line measured in the post-process. A comparison is made between two models: CAD model of DGTS and virtual model of the physical measured surface. And a matching rule is given to determine these two surfaces in an appropriate fashion. The developed error estimation model creates a point-to-point map of the real surface to the theoretical surface in the normal direction. A "pre-calibration error compensation" strategy is presented. Through processing the results of the first trail cutting, the total compensation error is predicted and an imaginary digital tooth surface is reconstructed. The machining errors in the final manufactured surfaces are minimized by generating this imaginary surface. An example of machining 2-D DGTS verifies the developed method. The research is of important theoretical and practical value to manufacture the DGTS and other digital conjugate surfaces.

  20. Study on characteristic parameters influencing laser-induced damage threshold of KH(2)PO(4) crystal surface machined by single point diamond turning.

    Science.gov (United States)

    Chen, Mingjun; Li, Mingquan; Cheng, Jian; Jiang, Wei; Wang, Jian; Xu, Qiao

    2011-12-01

    It has fundamental meaning to find the elements influencing the laser-induced damage threshold (LIDT) of KH(2)PO(4) (KDP) crystal and to provide suitable characterization parameters for these factors in order to improve the LIDT of KDP. Using single-point diamond turning (SPDT) to process the KDP crystal, the machined surface quality has important effects on its LIDT. However, there are still not suitable characteristic parameters of surface quality of KDP to correspond with the LIDT nowadays. In this paper, guided by the Fourier model theory, we study deeply the relationship between the relevant characteristic parameters of surface topography of KDP crystal and the experimental LIDT. Research results indicate that the waviness rather than the roughness is the leading topography element on the KDP surface machined by the SPDT method when the LIDT is considered and the amplitude of micro-waviness has greater influence on the light intensity inside the KDP crystal within the scope of dangerous frequencies between (180 μm)(-1) and (90 μm)(-1); with suitable testing equipment, the characteristic parameters of waviness amplitude, such as the arithmetical mean deviation of three-dimensional profile S(a) or root mean square deviation of three-dimensional contour S(q), are able to be considered as suitable parameters to reflect the optical quality of the machined surface in order to judge approximately the LIDT of the KDP surface and guide the machining course.

  1. Hardening Effect on Machined Surface for Precise Hard Cutting Process with Consideration of Tool Wear

    Institute of Scientific and Technical Information of China (English)

    YANG Yongheng

    2014-01-01

    During hard cutting process there is severe thermodynamic coupling effect between cutting tool and workpiece, which causes quenching effect on finished surfaces under certain conditions. However, material phase transformation mechanism of heat treatment in cutting process is different from the one in traditional process, which leads to changes of the formation mechanism of damaged layer on machined workpiece surface. This paper researches on the generation mechanism of damaged layer on machined surface in the process of PCBN tool hard cutting hardened steel Cr12MoV. Rules of temperature change on machined surface and subsurface are got by means of finite element simulation. In phase transformation temperature experiments rapid transformation instrument is employed, and the effect of quenching under cutting conditions on generation of damaged layer is revealed. Based on that, the phase transformation points of temperature under cutting conditions are determined. By experiment, the effects of cutting speed and tool wear on white layer thickness in damaged layer are revealed. The temperature distribution law of third deformation zone is got by establishing the numerical prediction model, and thickness of white layer in damaged layer is predicted, taking the tool wear effect into consideration. The experimental results show that the model prediction is accurate, and the establishment of prediction model provides a reference for wise selection of parameters in precise hard cutting process. For the machining process with high demanding on surface integrity, the generation of damaged layer on machined surface can be controlled precisely by using the prediction model.

  2. Surface performance of workpieces processed by electrical discharge machining in gas

    Institute of Scientific and Technical Information of China (English)

    LI Li-qing; BAI Ji-cheng; GUO Yong-feng; WANG Zhen-long

    2009-01-01

    The surface performance of workpieces processed by electrical discharge machining in gas (dry EDM) was studied in this paper. Firstly, the composition, micro hardness and recast layer of electrical discharge machined (EDMed) surface of 45 carbon steels in air were investigated through different test analysis methods. The results show that the workpiece surface EDMed in air contains a certain quantity of oxide, and oxidation occurs on the workpiece surface. Compared with the surface of workpieces processed in kerosene, fewer cracks exist on the dry EDMed workpiece surface, and the surface recast layer is thinner than that obtained by conventional EDM. The micro hardness of workpieces machined by dry EDM method is lower than that machined in kerosene, and higher than that of the matrix. In addition, experiments were conducted on the surface wear resistance of workpieces processed in air and kerosene using copper electrode and titanium alloy electrode.The results indicate that the surface wear resistance of workpieces processed in air can be improved, and it is related with tool material and dielectric.

  3. THIRD-ORDER LOCAL CONTACT AND APPLICATION IN 5-AXIS MACHINING OF SCULPTURED SURFACES

    Institute of Scientific and Technical Information of China (English)

    LIU Guran

    2006-01-01

    In order to increase the efficiency in the machining of the sculptured surfaces, the contact principle of differential geometry is applied to the 5-axis NC machining; The best contact condition between tool and the surfaces is researched. Through analysis the contact degree of the intersection line of the cutter and the surfaces is known. In comparison to previous studies, the theory is more restricted and accurate by going beyond the second-order parameters into the third-order, suiting both the primary surfaces of analytical geometry and the computer-generated surfaces of the computation geometry. It has definite procedure of calculation, and the equations are easy to solve. The thought process is very clear: First, suppose that there is a surface of third-order, the coefficients of which are arbitrary; Then find out the best posture of the circle in order that the circle and the surface will most closely contact with each other at the origin position; Finally, develop the surface into a third-order surface at every point of machining and employ the results mentioned above to find the best cutter posture at every point of machining. As a result, the equations are easy to solve, and the concept is clear.

  4. Water Quality of Hills Water, Supply Water and RO Water Machine at Ulu Yam Selangor

    Science.gov (United States)

    Ngadiman, N.; ‘I Bahari, N.; Kaamin, M.; Hamid, N. B.; Mokhtar, M.; Sahat, S.

    2016-07-01

    The rapid development resulted in the deterioration of the quality of drinking water in Malaysia. Recognizing the importance of water quality, new alternatives for drinking water such as mineral water processing from reverse osmosis (RO) machine become more popular. Hence, the demand for mineral water, natural spring water or water from the hills or mountains rose lately. More consumers believed the quality of these spring water better than other source of drinking water. However, the quality of all the drinking water sources is to meet the required quality standard. Therefore, this paper aims to measure the quality of the waters from hills, from RO machine and the water supply in Ulu Yam, Selangor Batang Kali, Malaysia. The water quality was determined based on following parameters: ammoniacal nitrogen (NH3), iron (Fe), turbidity (NTU) and pH. The results show that the water from hills has better quality compared to water supply and water from RO machine. The value of NH3 ranged from 0.03 mg/L- 0.67 mg/L; Fe was from 0.03mg/L - 0.12 mg/L, turbidity at 0.42 NTU - 0.88 NTU and pH is at 6.60 - 0.71. Based on the studied parameters, all three types of water are fit for drinking and have met the required national drinking water quality standard.

  5. Trim cut machining and surface integrity analysis of Nimonic 80A alloy using wire cut EDM

    Directory of Open Access Journals (Sweden)

    Amitesh Goswami

    2017-02-01

    Full Text Available This present work deals with the features of trim cut wire EDM machining of Nimonic 80A in terms of machining parameters, to predict material removal rate (MRR, surface roughness (Ra, wire wear ratio (WWR and microstructure analysis. Trim cut is performed after rough cut to remove the rough layer deposited after machining due to melting and re-solidification of the eroded metal from workpiece as well as from wire electrode. Taguchi’s design of experiments methodology has been used for planning and designing the experiments. The relative significance of various factors has also been evaluated and analyzed using ANOVA. The results clearly indicate trim cut potential for high surface finish compared to rough cut machining.

  6. Surface quality prediction model of nano-composite ceramics in ultrasonic vibration-assisted ELID mirror grinding

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Bo; Chen, Fan; Jia, Xiao-feng; Zhao, Chong-yang; Wang, Xiao-bo [Henan Polytechnic University, Jiaozuo (China)

    2017-04-15

    Ultrasonic vibration-assisted Electrolytic in-process dressing (ELID) grinding is a highly efficient and highly precise machining method. The surface quality prediction model in ultrasonic vibration-assisted ELID mirror grinding was studied. First, the interaction between grits and workpiece surface was analyzed according to kinematic mechanics, and the surface roughness model was developed. The variations in surface roughness under different parameters was subsequently calculated and analyzed by MATLAB. Results indicate that compared with the ordinary ELID grinding, ultrasonic vibration-assisted ELID grinding is superior, because it has more stable and better surface quality and has an improved range of ductile machining.

  7. Robust non-wetting PTFE surfaces by femtosecond laser machining.

    Science.gov (United States)

    Liang, Fang; Lehr, Jorge; Danielczak, Lisa; Leask, Richard; Kietzig, Anne-Marie

    2014-08-08

    Nature shows many examples of surfaces with extraordinary wettability,which can often be associated with particular air-trapping surface patterns. Here,robust non-wetting surfaces have been created by femtosecond laser ablation of polytetrafluoroethylene (PTFE). The laser-created surface structure resembles a forest of entangled fibers, which support structural superhydrophobicity even when the surface chemistry is changed by gold coating. SEM analysis showed that the degree of entanglement of hairs and the depth of the forest pattern correlates positively with accumulated laser fluence and can thus be influenced by altering various laser process parameters. The resulting fibrous surfaces exhibit a tremendous decrease in wettability compared to smooth PTFE surfaces; droplets impacting the virgin or gold coated PTFE forest do not wet the surface but bounce off. Exploratory bioadhesion experiments showed that the surfaces are truly air-trapping and do not support cell adhesion. Therewith, the created surfaces successfully mimic biological surfaces such as insect wings with robust anti-wetting behavior and potential for antiadhesive applications. In addition, the fabrication can be carried out in one process step, and our results clearly show the insensitivity of the resulting non-wetting behavior to variations in the process parameters,both of which make it a strong candidate for industrial applications.

  8. Robust Non-Wetting PTFE Surfaces by Femtosecond Laser Machining

    Directory of Open Access Journals (Sweden)

    Fang Liang

    2014-08-01

    Full Text Available Nature shows many examples of surfaces with extraordinary wettability, which can often be associated with particular air-trapping surface patterns. Here, robust non-wetting surfaces have been created by femtosecond laser ablation of polytetrafluoroethylene (PTFE. The laser-created surface structure resembles a forest of entangled fibers, which support structural superhydrophobicity even when the surface chemistry is changed by gold coating. SEM analysis showed that the degree of entanglement of hairs and the depth of the forest pattern correlates positively with accumulated laser fluence and can thus be influenced by altering various laser process parameters. The resulting fibrous surfaces exhibit a tremendous decrease in wettability compared to smooth PTFE surfaces; droplets impacting the virgin or gold coated PTFE forest do not wet the surface but bounce off. Exploratory bioadhesion experiments showed that the surfaces are truly air-trapping and do not support cell adhesion. Therewith, the created surfaces successfully mimic biological surfaces such as insect wings with robust anti-wetting behavior and potential for antiadhesive applications. In addition, the fabrication can be carried out in one process step, and our results clearly show the insensitivity of the resulting non-wetting behavior to variations in the process parameters, both of which make it a strong candidate for industrial applications.

  9. Influence of Cutting Parameters and Tool Wear on the Surface Integrity of Cobalt-Based Stellite 6 Alloy When Machined Under a Dry Cutting Environment

    Science.gov (United States)

    Yingfei, Ge; de Escalona, Patricia Muñoz; Galloway, Alexander

    2016-11-01

    The efficiency of a machining process can be measured by evaluating the quality of the machined surface and the tool wear rate. The research reported herein is mainly focused on the effect of cutting parameters and tool wear on the machined surface defects, surface roughness, deformation layer and residual stresses when dry milling Stellite 6, deposited by overlay on a carbon steel surface. The results showed that under the selected cutting conditions, abrasion, diffusion, peeling, chipping and breakage were the main tool wear mechanisms presented. Also the feed rate was the primary factor affecting the tool wear with an influence of 83%. With regard to the influence of cutting parameters on the surface roughness, the primary factors were feed rate and cutting speed with 57 and 38%, respectively. In addition, in general, as tool wear increased, the surface roughness increased and the deformation layer was found to be influenced more by the cutting parameters rather than the tool wear. Compressive residual stresses were observed in the un-machined surface, and when machining longer than 5 min, residual stress changed 100% from compression to tension. Finally, results showed that micro-crack initiation was the main mechanism for chip formation.

  10. Investigating Effect of Machining Parameters of CNC Milling on Surface Finish by Taguchi Method

    Directory of Open Access Journals (Sweden)

    Amit Joshi

    2012-08-01

    Full Text Available CNC End milling is a unique adaption of the conventional milling process which uses an end mill tool for the machining process. CNC Vertical End Milling Machining is a widely accepted material removal process used to manufacture components with complicated shapes and profiles. During the End milling process, the material is removed by the end mill cutter. The effects of various parameters of end milling process like spindle speed, depth of cut, feed rate have been investigated to reveal their Impact on surface finish using Taguchi Methodology. Experimental plan is performed by a Standard Orthogonal Array. The results of analysis of variance (ANOVA indicate that the feed Rate is most influencing factor for modeling surface finish. The graph of S-N Ratio indicates the optimal setting of the machining parameter which gives the optimum value of surface finish. The optimal set of process parameters has also been predicted to maximize the surface finish.

  11. Investigating Effect of Machining Parameters of CNC Milling on Surface Finish by Taguchi Method

    Directory of Open Access Journals (Sweden)

    Amit Joshi

    2013-08-01

    Full Text Available CNC End milling is a unique adaption of the conventional milling process which uses an end mill tool for the machining process. CNC Vertical End Milling Machining is a widely accepted material removal process used to manufacture components with complicated shapes and profiles. During the End milling process, the material is removed by the end mill cutter. The effects of various parameters of end milling process like spindle speed, depth of cut, feed rate have been investigated to reveal their Impact on surface finish using Taguchi Methodology. Experimental plan is performed by a Standard Orthogonal Array. The results of analysis of variance (ANOVA indicate that the feed Rate is most influencing factor for modelling surface finish. The graph of S-N Ratio indicates the optimal setting of the machining parameter which gives the optimum value of surface finish. The optimal set of process parameters has also been predicted to maximize the surface finish.

  12. Phase-locked loop based on machine surface topography measurement using lensed fibers

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Jin-Ho; Lee, ChaBum; Joo, Jae-Young; Lee, Sun-Kyu

    2011-02-01

    We present the phase-locked loop (PLL)-based metrology concept using lensed fibers for on-machine surface topography measurement. The shape of a single-mode fiber at the endface was designed using an ABCD matrix method, and two designed lensed fibers--the ball type and the tapered type--were fabricated, and the performance was evaluated, respectively. As a result, the interferometric fringe was not found in the case of the ball lensed fiber, but the machined surface could be measured by utilization of autofocusing and intensity methods. On the other hand, a very clear Fizeau interferometric fringe was observed in the case of the tapered lensed fiber. Its performance was compared with the results of the capacitance sensor and a commercially available white-light interferometer. We confirmed that PLL-based surface profile measurement using the tapered and ball lensed fibers can be applied for on-machine surface topography measurement applications.

  13. PENETRATION QUALITY EVALUATION IN ROBOTIZED ARC WELDING BASED ON SUPPORT VECTOR MACHINE

    Institute of Scientific and Technical Information of China (English)

    Ye Feng; Song Yonglun; Li Di; Lai Yizong

    2003-01-01

    A quality monitoring method by means of support vector machines (SVM) for robotized gas metal arc welding (GMAW) is introduced. Through the feature extraction of the welding process signal,a SVM classifier is constructed to establish the relationship between the feature of process parameters and the quality of weld penetration. Under the samples obtained from auto parts welding production line, the learning machine with a radial basis function kernel shows good performance. And this method can be feasible to identify defect online in welding production.

  14. A multi-perspective dynamic feature concept in adaptive NC machining of complex freeform surfaces

    OpenAIRE

    Liu, Xu; Li, Yingguang; Gao, James

    2016-01-01

    This paper presents a new concept of feature for freeform surface machining that defines the changes in feature status during real manufacturing situations which have not been sufficiently addressed by current international standards and previous research in feature technology. These changes are multi-perspective, including (i) changes in depth-of-cut: the geometry of a feature in the depth-of-cut direction changes during different machining operations such as roughing, semi-finishing and fin...

  15. Effect of Machining Parameters on Surface Integrity in Machining Nimonic C-263 Super Alloy Using Whisker-Reinforced Ceramic Insert

    Science.gov (United States)

    Ezilarasan, C.; Senthil kumar, V. S.; Velayudham, A.

    2013-06-01

    Whisker-reinforced ceramic inserts were used to conduct turning trials on nimonic C-263 super alloy to study the effect of different combinations of cutting parameters on surface integrity (roughness, microhardness, and residual stress) by employing energy dispersive spectroscopy, scanning electron microscopy, x-ray diffraction, and Vicker's microhardness test. Abrasion, adhesion and diffusion were found to be the main tool wear mechanisms in turning nimonic C-263 alloy. Based on characterization of surface roughness, a combination of 190 m/min cutting speed and 0.102 mm/rev feed rate was found to be the critical condition for turning nimonic C-263 alloy. Microhardness varied between 550 and 690 HV at the feed rates of 0.102-0.143 mm/rev for a cutting speed of 250 m/min after 9 min of turning. A tensile residual stress of 725-850 MPa on the machined surface was recorded at the preceding combination of cutting parameters. Cutting speed and cutting time had a dominant effect on the magnitude of the residual stress. No evidence of thermal relaxation and reduction in the degree of work hardening was noted during machining at high cutting speed.

  16. Optical micro-metrology of structured surfaces micro-machined by jet-ECM

    DEFF Research Database (Denmark)

    Quagliotti, Danilo; Tosello, Guido; Islam, Aminul

    2015-01-01

    A procedure for statistical analysis and uncertainty evaluation is presented with regards to measurements of step height and surface texture. Measurements have been performed with a focus-variation microscope over jet electrochemical micro-machined surfaces. Traceability has been achieved using...

  17. Optical micro-metrology of structured surfaces micro-machined by jet-ECM

    DEFF Research Database (Denmark)

    Quagliotti, Danilo; Tosello, Guido; Islam, Aminul

    A procedure for statistical analysis and uncertainty evaluation is presented with regards to measurements of step height and surface texture. Measurements have been performed with a focus-variation microscope over jet electrochemical micro-machined surfaces. Traceability has been achieved using...

  18. Improved Extreme Learning Machine and Its Application in Image Quality Assessment

    Directory of Open Access Journals (Sweden)

    Li Mao

    2014-01-01

    Full Text Available Extreme learning machine (ELM is a new class of single-hidden layer feedforward neural network (SLFN, which is simple in theory and fast in implementation. Zong et al. propose a weighted extreme learning machine for learning data with imbalanced class distribution, which maintains the advantages from original ELM. However, the current reported ELM and its improved version are only based on the empirical risk minimization principle, which may suffer from overfitting. To solve the overfitting troubles, in this paper, we incorporate the structural risk minimization principle into the (weighted ELM, and propose a modified (weighted extreme learning machine (M-ELM and M-WELM. Experimental results show that our proposed M-WELM outperforms the current reported extreme learning machine algorithm in image quality assessment.

  19. Configuration design and accuracy analysis of a novel magneto rheological finishing machine tool for concave surfaces with small radius of curvature

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Henan; Chen, Mingjun [Harbin Institute of Technology, Harbin (China); Yu, Bo; Zhen, Fang [China Electronics Technology Group Corporation No.26 Research Institute, Chongqing (China)

    2016-07-15

    Magnetorheological finishing (MRF) is a computer-controlled deterministic polishing technique that is widely used in the production of high-quality optics. In order to overcome the defects of existing MRF processes that are unable to achieve concave surfaces with small radius of curvature, a configuration method of a novel structured MRF machine tool using small ball-end permanent-magnet polishing head is proposed in this paper. The preliminary design focuses on the structural configuration of the machine, which includes the machine body, motion units and accessory equipment, and so on. Structural deformation and fabrication accuracy of the machine are analyzed theoretically, in which the reasonable structure sizes, manufacturing errors and assembly errors of main structural components are given for configuration optimization. Based on the theoretical analysis, a four-axes linkage MRF machine tool is developed. Preliminary experiments of spot polishing are carried out and the results indicate that the proposed MRF process can achieve stable polishing area which meets requirement of deterministic polishing. A typical small-bore complex component is polished on the developed device and fine surface quality is obtained with sphericity of the finished spherical surfaces 1.3 μm and surface roughness Ra less than 0.018 μm.

  20. Determination of real machine-tool settings and minimization of real surface deviation by computerized inspection

    Science.gov (United States)

    Litvin, Faydor L.; Kuan, Chihping; Zhang, YI

    1991-01-01

    A numerical method is developed for the minimization of deviations of real tooth surfaces from the theoretical ones. The deviations are caused by errors of manufacturing, errors of installment of machine-tool settings and distortion of surfaces by heat-treatment. The deviations are determined by coordinate measurements of gear tooth surfaces. The minimization of deviations is based on the proper correction of initially applied machine-tool settings. The contents of accomplished research project cover the following topics: (1) Descriptions of the principle of coordinate measurements of gear tooth surfaces; (2) Deviation of theoretical tooth surfaces (with examples of surfaces of hypoid gears and references for spiral bevel gears); (3) Determination of the reference point and the grid; (4) Determination of the deviations of real tooth surfaces at the points of the grid; and (5) Determination of required corrections of machine-tool settings for minimization of deviations. The procedure for minimization of deviations is based on numerical solution of an overdetermined system of n linear equations in m unknowns (m much less than n ), where n is the number of points of measurements and m is the number of parameters of applied machine-tool settings to be corrected. The developed approach is illustrated with numerical examples.

  1. Surfaces. [characterization of surface properties for predicting bond quality

    Science.gov (United States)

    Buckley, D. H.

    1983-01-01

    Techniques for the characterization of surface cleanliness and roughness for predicting the quality of an adhesive bond are outlined. Generally, smooth surfaces are only available from cleavage of crystalline materials along a natural cleavage plane. Films must be deposited on metal surfaces to achieve the same smoothness. Once the surfaces are clean, however, reaction with the ambient atmosphere becomes likely through diffusive and absorption processes, producing asperities. Electron diffraction, Auger electron, and X ray emission spectroscopy are used to characterize surface condition. Once the surface is observed to be clean, the application of an adhesive will usually prohibit separation along the adhesive; separation is then confined to the weaker of the two materials. Finally, the use of polytetrafluorothylene adhesive to test the adhesion between polymers and metal surfaces is described.

  2. Metrological Aspects of Surface Topographies Produced by Different Machining Operations Regarding Their Potential Functionality

    Directory of Open Access Journals (Sweden)

    Żak Krzysztof

    2017-06-01

    Full Text Available This paper presents a comprehensive methodology for measuring and characterizing the surface topographies on machined steel parts produced by precision machining operations. The performed case studies concern a wide spectrum of topographic features of surfaces with different geometrical structures but the same values of the arithmetic mean height Sa. The tested machining operations included hard turning operations performed with CBN tools, grinding operations with Al2O3 ceramic and CBN wheels and superfinish using ceramic stones. As a result, several characteristic surface textures with the Sa roughness parameter value of about 0.2 μm were thoroughly characterized and compared regarding their potential functional capabilities. Apart from the standard 2D and 3D roughness parameters, the fractal, motif and frequency parameters were taken in the consideration.

  3. Research on postprocessing of seven-axis linkage parallel kinematics machine with complicated surfaces

    Institute of Scientific and Technical Information of China (English)

    WEI Yong-geng; SHI Yong; ZHAO Kun

    2007-01-01

    Because of restriction of workspace of parallel kinematics Machine (PKM), 6 DOF PKM can't finish machining of workpiece with complicated surfaces under only once locating. It is necessary to fit workpiece beyond twice and to lead to low machining precision. Therefore the seven-axis linkage PKM is implemented by fixing a turntable on the worktable of the six-axis linkage PKM. However, the turntable angle decomposing problem from the CL file should be well considered. If the traditional decomposing methods are adopted, the nutation angle usually goes beyond the workspace of the machine. Therefore, according to the relation of the machine coordinate system and the workpiece coordinate system, the turntable angle decomposition algorithmic of the consistent coordinate system and the turntable angle decomposition algorithmic of the non-consistent coordinate system are developed to resolve the problem mentioned above. The turntable angle decomposition of the non-consistent coordinate system processes the decomposition which is based on the consistent coordinate system again. It calculates the initial angle of the locating workpiece, and the decomposed angle of the turntable at the machine coordinate system results in the nutation angle not going beyond workspace of the machine, thereby the decomposition process can be simplified.

  4. Study on the nano machining process with a vibrating AFM tip on the polymer surface

    Energy Technology Data Exchange (ETDEWEB)

    Liu Weitao [State Key Laboratory of Robotics and Systems, Robotics Institute, Harbin Institute of Technology, Harbin 150080 (China); Center for Precision Engineering, Harbin Institute of Technology, Harbin, Heilongjiang 150001 (China); Yan Yongda, E-mail: yanyongda@yahoo.com.cn [State Key Laboratory of Robotics and Systems, Robotics Institute, Harbin Institute of Technology, Harbin 150080 (China); Center for Precision Engineering, Harbin Institute of Technology, Harbin, Heilongjiang 150001 (China); Hu Zhenjiang; Zhao Xuesen; Yan Jiucun; Dong Shen [Center for Precision Engineering, Harbin Institute of Technology, Harbin, Heilongjiang 150001 (China)

    2012-01-15

    The polymer has been proved to be nano machined by a vibrating tip in tapping mode of Atomic Force Microscope (AFM). The force between the tip and the surface is an important factor which determines success of the machining process. Controlling this force with high accuracy is the foundation of nanomachining in AFM tapping mode. To achieve a deeper understanding on this process, the tip is modeled as a driving oscillator with damping. Factors affecting the nano machining process are studied. The Hertz elastic contact theory is used to calculate the maximum contact pressure applied by the tip which is employed as a criterion to judge the deformation state of the sample. The simulation results show that: The driven amplitude can be used as a main parameter of controlling the machined depth. Sharper tips and harder cantilevers should be used for successful nanomachining with the vibrating tip. Under the same conditions, a larger tip radius will not only result in the machining error, but also lead to failure of the nanomachining process. The higher driving frequency will lead to a larger tapping force. However it cannot be used as a parameter to control the machined depth because of its narrow variation range. But it is a main error source for the nanomachining process in AFM tapping mode. Moreover, a larger Young's modulus polymer sample will induce a smaller machined depth, a larger maximum contact pressure and a bigger tapping force.

  5. Surface Flux Modeling for Air Quality Applications

    Directory of Open Access Journals (Sweden)

    Limei Ran

    2011-08-01

    Full Text Available For many gasses and aerosols, dry deposition is an important sink of atmospheric mass. Dry deposition fluxes are also important sources of pollutants to terrestrial and aquatic ecosystems. The surface fluxes of some gases, such as ammonia, mercury, and certain volatile organic compounds, can be upward into the air as well as downward to the surface and therefore should be modeled as bi-directional fluxes. Model parameterizations of dry deposition in air quality models have been represented by simple electrical resistance analogs for almost 30 years. Uncertainties in surface flux modeling in global to mesoscale models are being slowly reduced as more field measurements provide constraints on parameterizations. However, at the same time, more chemical species are being added to surface flux models as air quality models are expanded to include more complex chemistry and are being applied to a wider array of environmental issues. Since surface flux measurements of many of these chemicals are still lacking, resistances are usually parameterized using simple scaling by water or lipid solubility and reactivity. Advances in recent years have included bi-directional flux algorithms that require a shift from pre-computation of deposition velocities to fully integrated surface flux calculations within air quality models. Improved modeling of the stomatal component of chemical surface fluxes has resulted from improved evapotranspiration modeling in land surface models and closer integration between meteorology and air quality models. Satellite-derived land use characterization and vegetation products and indices are improving model representation of spatial and temporal variations in surface flux processes. This review describes the current state of chemical dry deposition modeling, recent progress in bi-directional flux modeling, synergistic model development research with field measurements, and coupling with meteorological land surface models.

  6. Quality Assessment of Adaptive Bitrate Videos using Image Metrics and Machine Learning

    DEFF Research Database (Denmark)

    Søgaard, Jacob; Forchhammer, Søren; Brunnström, Kjell

    2015-01-01

    Adaptive bitrate (ABR) streaming is widely used for distribution of videos over the internet. In this work, we investigate how well we can predict the quality of such videos using well-known image metrics, information about the bitrate levels, and a relatively simple machine learning method...

  7. An Evaluation of Output Quality of Machine Translation (Padideh Software vs. Google Translate)

    Science.gov (United States)

    Azer, Haniyeh Sadeghi; Aghayi, Mohammad Bagher

    2015-01-01

    This study aims to evaluate the translation quality of two machine translation systems in translating six different text-types, from English to Persian. The evaluation was based on criteria proposed by Van Slype (1979). The proposed model for evaluation is a black-box type, comparative and adequacy-oriented evaluation. To conduct the evaluation, a…

  8. Meat Quality Assessment by Electronic Nose (Machine Olfaction Technology

    Directory of Open Access Journals (Sweden)

    Sundar Balasubramanian

    2009-07-01

    Full Text Available Over the last twenty years, newly developed chemical sensor systems (so called “electronic noses” have made odor analyses possible. These systems involve various types of electronic chemical gas sensors with partial specificity, as well as suitable statistical methods enabling the recognition of complex odors. As commercial instruments have become available, a substantial increase in research into the application of electronic noses in the evaluation of volatile compounds in food, cosmetic and other items of everyday life is observed. At present, the commercial gas sensor technologies comprise metal oxide semiconductors, metal oxide semiconductor field effect transistors, organic conducting polymers, and piezoelectric crystal sensors. Further sensors based on fibreoptic, electrochemical and bi-metal principles are still in the developmental stage. Statistical analysis techniques range from simple graphical evaluation to multivariate analysis such as artificial neural network and radial basis function. The introduction of electronic noses into the area of food is envisaged for quality control, process monitoring, freshness evaluation, shelf-life investigation and authenticity assessment. Considerable work has already been carried out on meat, grains, coffee, mushrooms, cheese, sugar, fish, beer and other beverages, as well as on the odor quality evaluation of food packaging material. This paper describes the applications of these systems for meat quality assessment, where fast detection methods are essential for appropriate product management. The results suggest the possibility of using this new technology in meat handling.

  9. Surface Finish and Residual Stresses Induced by Orthogonal Dry Machining of AA7075-T651

    Directory of Open Access Journals (Sweden)

    Walid Jomaa

    2014-02-01

    Full Text Available The surface finish was extensively studied in usual machining processes (turning, milling, and drilling. For these processes, the surface finish is strongly influenced by the cutting feed and the tool nose radius. However, a basic understanding of tool/surface finish interaction and residual stress generation has been lacking. This paper aims to investigate the surface finish and residual stresses under the orthogonal cutting since it can provide this information by avoiding the effect of the tool nose radius. The orthogonal machining of AA7075-T651 alloy through a series of cutting experiments was performed under dry conditions. Surface finish was studied using height and amplitude distribution roughness parameters. SEM and EDS were used to analyze surface damage and built-up edge (BUE formation. An analysis of the surface topography showed that the surface roughness was sensitive to changes in cutting parameters. It was found that the formation of BUE and the interaction between the tool edge and the iron-rich intermetallic particles play a determinant role in controlling the surface finish during dry orthogonal machining of the AA7075-T651 alloy. Hoop stress was predominantly compressive on the surface and tended to be tensile with increased cutting speed. The reverse occurred for the surface axial stress. The smaller the cutting feed, the greater is the effect of cutting speed on both axial and hoop stresses. By controlling the cutting speed and feed, it is possible to generate a benchmark residual stress state and good surface finish using dry machining.

  10. Evaluation Of Electrochemical Machining Technology For Surface Improvements In Additive Manufactured Components

    Energy Technology Data Exchange (ETDEWEB)

    Dehoff, Ryan R [ORNL; List III, Frederick Alyious [ORNL; Carver, Keith [ORNL

    2015-09-23

    ORNL Manufacturing Demonstration Facility worked with ECM Technologies LLC to investigate the use of precision electro-chemical machining technology to polish the surface of parts created by Arcam electron beam melting. The goals for phase one of this project have been met. The project goal was to determine whether electro-chemical machining is a viable method to improve the surface finish of Inconel 718 parts fabricated using the Arcam EBM method. The project partner (ECM) demonstrated viability for parts of both simple and complex geometry. During the course of the project, detailed process knowledge was generated. This project has resulted in the expansion of United States operations for ECM Technologies.

  11. An experimental result of surface roughness machining performance in deep hole drilling

    Directory of Open Access Journals (Sweden)

    Mohamad Azizah

    2016-01-01

    Full Text Available This study presents an experimental result of a deep hole drilling process for Steel material at different machining parameters which are feed rate (f, spindle speed (s, the depth of the hole (d and MQL, number of drops (m on surface roughness, Ra. The experiment was designed using two level full factorial design of experiment (DoE with centre points to collect surface roughness, Ra values. The signal to noise (S/N ratio analysis was used to discover the optimum level for each machining parameters in the experiment.

  12. Technical note: Evaluation of three machine learning models for surface ocean CO2 mapping

    Science.gov (United States)

    Zeng, Jiye; Matsunaga, Tsuneo; Saigusa, Nobuko; Shirai, Tomoko; Nakaoka, Shin-ichiro; Tan, Zheng-Hong

    2017-04-01

    Reconstructing surface ocean CO2 from scarce measurements plays an important role in estimating oceanic CO2 uptake. There are varying degrees of differences among the 14 models included in the Surface Ocean CO2 Mapping (SOCOM) inter-comparison initiative, in which five models used neural networks. This investigation evaluates two neural networks used in SOCOM, self-organizing maps and feedforward neural networks, and introduces a machine learning model called a support vector machine for ocean CO2 mapping. The technique note provides a practical guide to selecting the models.

  13. Effect of Ceramic Surface Treatments After Machine Grinding on the Biaxial Flexural Strength of Different CAD/CAM Dental Ceramics.

    Science.gov (United States)

    Bagheri, Hossein; Hooshmand, Tabassom; Aghajani, Farzaneh

    2015-09-01

    This study aimed to evaluate the effect of different ceramic surface treatments after machining grinding on the biaxial flexural strength (BFS) of machinable dental ceramics with different crystalline phases. Disk-shape specimens (10mm in diameter and 1.3mm in thickness) of machinable ceramic cores (two silica-based and one zirconia-based ceramics) were prepared. Each type of the ceramic surfaces was then randomly treated (n=15) with different treatments as follows: 1) machined finish as control, 2) machined finish and sandblasting with alumina, and 3) machined finish and hydrofluoric acid etching for the leucite and lithium disilicate-based ceramics, and for the zirconia; 1) machined finish and post-sintered as control, 2) machined finish, post-sintered, and sandblasting, and 3) machined finish, post-sintered, and Nd;YAG laser irradiation. The BFS were measured in a universal testing machine. Data based were analyzed by ANOVA and Tukey's multiple comparisons post-hoc test (α=0.05). The mean BFS of machined finish only surfaces for leucite ceramic was significantly higher than that of sandblasted (P=0.001) and acid etched surfaces (P=0.005). A significantly lower BFS was found after sandblasting for lithium disilicate compared with that of other groups (Pceramics was affected by the type of ceramic material and surface treatment method. Sandblasting with alumina was detrimental to the strength of only silica-based ceramics. Nd:YAG laser irradiation may lead to substantial strength degradation of zirconia.

  14. A proposed model for assessing service quality in small machining and industrial maintenance companies

    Directory of Open Access Journals (Sweden)

    Morvam dos Santos Netto

    2014-11-01

    Full Text Available Machining and industrial maintenance services include repair (corrective maintenance of equipments, activities involving the assembly-disassembly of equipments, fault diagnosis, machining operations, forming operations, welding processes, assembly and test of equipments. This article proposes a model for assessing the quality of services provided by small machining and industrial maintenance companies, since there is a gap in the literature regarding this issue and because the importance of small service companies in socio-economic development of the country. The model is an adaptation of the SERVQUAL instrument and the criteria determining the quality of services are designed according to the service cycle of a typical small machining and industrial maintenance company. In this sense, the Moments of Truth have been considered in the preparation of two separate questionnaires. The first questionnaire contains 24 statements that reflect the expectations of customers, and the second one contains 24 statements that measure perceptions of service performance. An additional item was included in each questionnaire to assess, respectively, the overall expectation about the services and the overall company performance. Therefore, it is a model that considers the interfaces of the client/supplier relationship, the peculiarities of the machining and industrial maintenance service sector and the company size.

  15. An Axial Sliding Test for machine elements surfaces

    DEFF Research Database (Denmark)

    Godi, Alessandro; Grønbæk, J.; Mohaghegh, Kamran

    2012-01-01

    liners. To prove the efficacy of a particular textured surface, it is paramount to perform experimental tests under controlled laboratory conditions. In this paper a new test rig simulating pure sliding conditions is presented, dubbed Axial Sliding Test. It presents four major components: a rod, a sleeve......, a housing and a stripwound container. The rod and the sleeve are the two surfaces in relative sliding motion; the stripwound container maintains a constant, but adjustable normal pressure and the housing serves as interface between the sleeve and the container. For carrying out the test, two machineries...... turned rod against a mirror-polished sleeve. Qualitatively the multifunctional surfaces improve the friction conditions, but a more structured test campaign is required....

  16. Normal contour error measurement on-machine and compensation method for polishing complex surface by MRF

    Science.gov (United States)

    Chen, Hua; Chen, Jihong; Wang, Baorui; Zheng, Yongcheng

    2016-10-01

    The Magnetorheological finishing (MRF) process, based on the dwell time method with the constant normal spacing for flexible polishing, would bring out the normal contour error in the fine polishing complex surface such as aspheric surface. The normal contour error would change the ribbon's shape and removal characteristics of consistency for MRF. Based on continuously scanning the normal spacing between the workpiece and the finder by the laser range finder, the novel method was put forward to measure the normal contour errors while polishing complex surface on the machining track. The normal contour errors was measured dynamically, by which the workpiece's clamping precision, multi-axis machining NC program and the dynamic performance of the MRF machine were achieved for the verification and security check of the MRF process. The unit for measuring the normal contour errors of complex surface on-machine was designed. Based on the measurement unit's results as feedback to adjust the parameters of the feed forward control and the multi-axis machining, the optimized servo control method was presented to compensate the normal contour errors. The experiment for polishing 180mm × 180mm aspherical workpiece of fused silica by MRF was set up to validate the method. The results show that the normal contour error was controlled in less than 10um. And the PV value of the polished surface accuracy was improved from 0.95λ to 0.09λ under the conditions of the same process parameters. The technology in the paper has been being applied in the PKC600-Q1 MRF machine developed by the China Academe of Engineering Physics for engineering application since 2014. It is being used in the national huge optical engineering for processing the ultra-precision optical parts.

  17. Study of cutting forces in machining of magnesium composite by response surface methodology

    Directory of Open Access Journals (Sweden)

    M. Saravanakumar

    2015-01-01

    Full Text Available Metal Matrix composites (MMCs has many excellent engineering properties like good strength to weight ratio, stiffness and increased wear resistance etc., These properties are the main requirements in aerospace, automotive industries and hence the MMCs are extensively used in these industries. This paper presents the detailed experimental study on cutting forces and surface roughness aspects in turning of 5% Graphite reinforced AZ91D Magnesium alloy metal matrix composite (AZ91D Magnesium alloy matrix + 5 % Graphite reinforcement. The stir casting process under inert atmosphere is followed for synthesis of the composite. The turning process is followed using Tungsten carbide cutting tool, in a lathe. The effect of machining parameters viz., cutting speed, feed rate and depth of cut, on the cutting forces and surface roughness (Ra achieved during the machining are analysed and modelled through the response surface methodology (RSM. Study of effect of machining parameters and their interactions are carried out by using the surface, contour plots of RSM. The experimental result shows that the most significant machining parameter affecting surface roughness and cutting forces is cutting speed. The experimental results and predicted values are observed as in good agreement.

  18. Assessment of factors influencing surface roughness on the machining of Al/SiC particulate composites

    Energy Technology Data Exchange (ETDEWEB)

    Palanikumar, K. [Department of Mechanical and Production Engineering, Sathyabama Institute of Science and Technology, Deemed University, Chennai 600 119, Tamilnadu (India)]. E-mail: palanikumar_k@yahoo.com; Karthikeyan, R. [Department of Manufacturing Engineering, Annamalai University, Chidambaram 608001 (India)

    2007-07-01

    The utilization of Al/SiC particulate composite materials in many different engineering fields has undergone a tremendous increase. Accordingly, the need for accurate machining of composites has increased enormously. In the present study, an attempt has been made to assess the factors influencing surface roughness on the machining of Al/SiC particulate composites. Experimental design concept has been used for experimentation. The machining experiments were conducted on lathe using tungsten carbide tool inserts (K10) with two levels of factors. The factors considered were: % volume fraction of SiC, cutting speed, depth of cut and feed rate. A procedure has been developed to assess and optimize the chosen factors to attain minimum surface roughness by incorporating: (i) response table and response graph, (ii) normal probability plot (iii) interaction graphs and (iv) analysis of variance (ANOVA) technique.

  19. Auditory inspired machine learning techniques can improve speech intelligibility and quality for hearing-impaired listeners.

    Science.gov (United States)

    Monaghan, Jessica J M; Goehring, Tobias; Yang, Xin; Bolner, Federico; Wang, Shangqiguo; Wright, Matthew C M; Bleeck, Stefan

    2017-03-01

    Machine-learning based approaches to speech enhancement have recently shown great promise for improving speech intelligibility for hearing-impaired listeners. Here, the performance of three machine-learning algorithms and one classical algorithm, Wiener filtering, was compared. Two algorithms based on neural networks were examined, one using a previously reported feature set and one using a feature set derived from an auditory model. The third machine-learning approach was a dictionary-based sparse-coding algorithm. Speech intelligibility and quality scores were obtained for participants with mild-to-moderate hearing impairments listening to sentences in speech-shaped noise and multi-talker babble following processing with the algorithms. Intelligibility and quality scores were significantly improved by each of the three machine-learning approaches, but not by the classical approach. The largest improvements for both speech intelligibility and quality were found by implementing a neural network using the feature set based on auditory modeling. Furthermore, neural network based techniques appeared more promising than dictionary-based, sparse coding in terms of performance and ease of implementation.

  20. Single point diamond machining of optical and related mounting surfaces

    Science.gov (United States)

    Mladjan, Gary J.

    2002-09-01

    Over the past several years we have designed and fabricated several variations of a three mirror anistigmat Telescope for a Risk Reduction effort. In order to achieve passive athermalization, use of the same materials for both mirrors and structures is desirable. We fabricated 2 telescopes using investment cast aluminum alloy A356 in the first and investment cast Aluminum/Beryllium alloy 191 in the second, for all components. All optical surfaces and corresponding mounting surfaces are nickel plated and single point diamond tuned. The telescopes were assembled to meet the optical prescription tolerances with no alignment required other than focus. Components and performance levels are totally interchangeable between the telescopes, except for athermalization issues.

  1. Quality Monitoring for Laser Welding Based on High-Speed Photography and Support Vector Machine

    Directory of Open Access Journals (Sweden)

    Teng Wang

    2017-03-01

    Full Text Available In order to improve the prediction ability of welding quality during high-power disk laser welding, a new approach was proposed and applied in the classification of the dynamic features of metal vapor plume. Six features were extracted through the color image processing method. Three features, including the area of plume, number of spatters, and horizontal coordinate of plume centroid, were selected based on the classification accuracy rates and Pearson product-moment correlation coefficients. A support vector machine model was adopted to classify the welding quality status into two categories, good or poor. The results demonstrated that the support vector machine model established according to the selected features had satisfactory prediction and generalization ability. The classification accuracy rate was higher than 90%, and the model could be applied in the prediction of welding quality during high-power disk laser welding.

  2. Machining process influence on the chip form and surface roughness by neuro-fuzzy technique

    Science.gov (United States)

    Anicic, Obrad; Jović, Srđan; Aksić, Danilo; Skulić, Aleksandar; Nedić, Bogdan

    2017-04-01

    The main aim of the study was to analyze the influence of six machining parameters on the chip shape formation and surface roughness as well during turning of Steel 30CrNiMo8. Three components of cutting forces were used as inputs together with cutting speed, feed rate, and depth of cut. It is crucial for the engineers to use optimal machining parameters to get the best results or to high control of the machining process. Therefore, there is need to find the machining parameters for the optimal procedure of the machining process. Adaptive neuro-fuzzy inference system (ANFIS) was used to estimate the inputs influence on the chip shape formation and surface roughness. According to the results, the cutting force in direction of the depth of cut has the highest influence on the chip form. The testing error for the cutting force in direction of the depth of cut has testing error 0.2562. This cutting force determines the depth of cut. According to the results, the depth of cut has the highest influence on the surface roughness. Also the depth of cut has the highest influence on the surface roughness. The testing error for the cutting force in direction of the depth of cut has testing error 5.2753. Generally the depth of cut and the cutting force which provides the depth of cut are the most dominant factors for chip forms and surface roughness. Any small changes in depth of cut or in cutting force which provide the depth of cut could drastically affect the chip form or surface roughness of the working material.

  3. Surface topography characterization using an atomic force microscope mounted on a coordinate measuring machine

    DEFF Research Database (Denmark)

    De Chiffre, Leonardo; Hansen, H.N; Kofod, N

    1999-01-01

    The paper describes the construction, testing and use of an integrated system for topographic characterization of fine surfaces on parts having relatively big dimensions. An atomic force microscope (AFM) was mounted on a manual three-coordinate measuring machine (CMM) achieving free positioning...

  4. On-line welding quality inspection system for steel pipe based on machine vision

    Science.gov (United States)

    Yang, Yang

    2017-05-01

    In recent years, high frequency welding has been widely used in production because of its advantages of simplicity, reliability and high quality. In the production process, how to effectively control the weld penetration welding, ensure full penetration, weld uniform, so as to ensure the welding quality is to solve the problem of the present stage, it is an important research field in the field of welding technology. In this paper, based on the study of some methods of welding inspection, a set of on-line welding quality inspection system based on machine vision is designed.

  5. Prediction of Surface Roughness Based on Machining Condition and Tool Condition in Boring EN31 Steel

    Directory of Open Access Journals (Sweden)

    P. Mohanaraman

    2016-04-01

    Full Text Available Prediction of Surface roughness plays a vital role in manufacturing process. In manufacturing industries, productions of metallic materials require high surface finish in various components. In the present work, the effect of spindle speed, feed rate, depth of cut and flank wear of the tool on the surface roughness has been studied. Carbide tipped insert was used for boring operation. Experiments were conducted in CNC lathe. The experimental setup was prepared with sixteen levels of cutting parameters and was conducted with two tool tip conditions in dry machining. A piezoelectric accelerometer was used to measure the vibrational signals while machining. The data acquisition card which connected between accelerometer and lab-view software to record the signals. Simple linear and least median regression models were used for prediction of surface roughness. The models were developed by weka analysis software. The best suitable regression model is implemented based on maximum correlation coefficient and the minimum error values.

  6. Vibration reliability analysis for aeroengine compressor blade based on support vector machine response surface method

    Institute of Scientific and Technical Information of China (English)

    GAO Hai-feng; BAI Guang-chen

    2015-01-01

    To ameliorate reliability analysis efficiency for aeroengine components, such as compressor blade, support vector machine response surface method (SRSM) is proposed. SRSM integrates the advantages of support vector machine (SVM) and traditional response surface method (RSM), and utilizes experimental samples to construct a suitable response surface function (RSF) to replace the complicated and abstract finite element model. Moreover, the randomness of material parameters, structural dimension and operating condition are considered during extracting data so that the response surface function is more agreeable to the practical model. The results indicate that based on the same experimental data, SRSM has come closer than RSM reliability to approximating Monte Carlo method (MCM); while SRSM (17.296 s) needs far less running time than MCM (10958 s) and RSM (9840 s). Therefore, under the same simulation conditions, SRSM has the largest analysis efficiency, and can be considered a feasible and valid method to analyze structural reliability.

  7. Study of the Productivity and Surface Quality of Hybrid EDM

    Science.gov (United States)

    Wankhade, Sandeepkumar Haribhau; Sharma, Sunil Bansilal

    2016-01-01

    The development of new, advanced engineering materials and the need for precise prototypes and low-volume production have made the electric discharge machining (EDM), an important manufacturing process to meet such demands. It is capable of machining geometrically complex and hard material components, that are precise and difficult-to-machine such as heat treated tool steels, composites, super alloys, ceramics, carbides etc. Conversely the low MRR limits its productivity. Abrasive water jet machine (AJM) tools are quick to setup and offer quick turn-around on the machine and could make parts out of virtually any material. They do not heat the material hence no heat affected zone and can make any intricate shape easily. The main advantages are flexibility, low heat production and ability to machine hard and brittle materials. Main disadvantages comprise the process produces a tapered cut and health hazards due to dry abrasives. To overcome the limitations and exploit the best of each of above processes; an attempt has been made to hybridize the processes of AJM and EDM. The appropriate abrasives routed with compressed air through the hollow electrode to construct the hybrid process i.e., abrasive jet electric discharge machining (AJEDM), the high speed abrasives could impinge on the machined surface to remove the recast layer caused by EDM process. The main process parameters were varied to explore their effects and experimental results show that AJEDM enhances the machining efficiency with better surface finish hence can fit the requirements of modern manufacturing applications.

  8. Contributions to understanding the high speed machining effects on aeronautic part surface integrity

    Science.gov (United States)

    Jomaa, Walid

    To remain competitive, the aeronautic industry has increasing requirements for mechanical components and parts with high functional performance and longer in-service life. The improvement of the in-service life of components can be achieved by mastering and optimizing the surface integrity of the manufactured parts. Thus, the present study attempted to investigate, experimentally and theoretically, the tool/work material interactions on part surface integrity during the machining of aluminium alloys and hardened materials (low alloy steels) using orthogonal machining tests data. The studied materials are two aluminum alloys (6061-T6 and 7075-T651) and AISI 4340 steel. The AISI 4340 steel was machined after been induction heat treated to 58-60 HRC. These materials were selected in an attempt to provide a comprehensive study for the machining of metals with different behaviours (ductile and hard material). The proposed approach is built on three steps. First, we proposed a design of experiment (DOE) to analyse, experimentally, the chip formation and the resulting surface integrity during the high speed machining under dry condition. The orthogonal cutting mode, adopted in these experiments, allowed to explore, theoretically, the effects of technological (cutting speed and feed) and physical (cutting forces, temperature, shear angle, friction angle, and length Contact tool/chip) parameters on the chip formation mechanisms and the machined surface characteristics (residual stress, plastic deformation, phase transformation, etc.). The cutting conditions were chosen while maintaining a central composite design (CCD) with two factors (cutting speed and feed per revolution). For the aluminum 7075-T651, the results showed that the formation of BUE and the interaction between the tool edge and the iron-rich intermetallic particles are the main causes of the machined surface damage. The BUE formation increases with the cutting feed while the increase of the cutting speed

  9. Influence of roughness of machined surface on adhesion of anticorrosion system

    Directory of Open Access Journals (Sweden)

    Jiří Votava

    2013-01-01

    Full Text Available The goal of this experiment is to analyse dependence of roughness of machined surface on adhesion performance of various anticorrosion systems. In order to prepare samples for the experiment, samples were milled on a knee and column type of a horizontal milling machine. Depending on cutting conditions and machining tool, there were set intervals of roughness of machined surface which are commonly achievable on this type of machine. It is a roughness in the interval of 0.4–1.6 µm (finishing, 1.6–6.3 µm (standard milling a 6.3–12.5 µm (roughening. Removable cutting tips were used as a machining tool and for roughening, a shell end milling cutter NAREX 63x40 HSS 90 was used. Three types of anticorrosion systems were used in order to analyse the adhesion, that is a water-thinnable system Eternal, synthetic single layer coating Hostagrund and a duplex system, whose first layer is formed by dipped zinc and a top layer by a single-layer acrylate system Zinorex. Testing of the influence of surface roughness (anchoring system on adhesion of the individual anticorrosion systems were processed in compliance with the norm ČSN EN ISO 4624, a tearing test. The main criterion of adhesion of anticorrosion system is defined as a power which needed for tear-off testing object stuck to a tested sample. This analysis was processed also during the corrosion test in the salt spray environment according to the norm ČSN EN ISO 9227. In order to better identify the adhesion of the individual anticorrosion systems, the analysis of undercorrosion according to the norm ISO 4628-8 was processed.

  10. SVD-based quality metric for image and video using machine learning.

    Science.gov (United States)

    Narwaria, Manish; Lin, Weisi

    2012-04-01

    We study the use of machine learning for visual quality evaluation with comprehensive singular value decomposition (SVD)-based visual features. In this paper, the two-stage process and the relevant work in the existing visual quality metrics are first introduced followed by an in-depth analysis of SVD for visual quality assessment. Singular values and vectors form the selected features for visual quality assessment. Machine learning is then used for the feature pooling process and demonstrated to be effective. This is to address the limitations of the existing pooling techniques, like simple summation, averaging, Minkowski summation, etc., which tend to be ad hoc. We advocate machine learning for feature pooling because it is more systematic and data driven. The experiments show that the proposed method outperforms the eight existing relevant schemes. Extensive analysis and cross validation are performed with ten publicly available databases (eight for images with a total of 4042 test images and two for video with a total of 228 videos). We use all publicly accessible software and databases in this study, as well as making our own software public, to facilitate comparison in future research.

  11. Figure of merit for macrouniformity based on image quality ruler evaluation and machine learning framework

    Science.gov (United States)

    Wang, Weibao; Overall, Gary; Riggs, Travis; Silveston-Keith, Rebecca; Whitney, Julie; Chiu, George; Allebach, Jan P.

    2013-01-01

    Assessment of macro-uniformity is a capability that is important for the development and manufacture of printer products. Our goal is to develop a metric that will predict macro-uniformity, as judged by human subjects, by scanning and analyzing printed pages. We consider two different machine learning frameworks for the metric: linear regression and the support vector machine. We have implemented the image quality ruler, based on the recommendations of the INCITS W1.1 macro-uniformity team. Using 12 subjects at Purdue University and 20 subjects at Lexmark, evenly balanced with respect to gender, we conducted subjective evaluations with a set of 35 uniform b/w prints from seven different printers with five levels of tint coverage. Our results suggest that the image quality ruler method provides a reliable means to assess macro-uniformity. We then defined and implemented separate features to measure graininess, mottle, large area variation, jitter, and large-scale non-uniformity. The algorithms that we used are largely based on ISO image quality standards. Finally, we used these features computed for a set of test pages and the subjects' image quality ruler assessments of these pages to train the two different predictors - one based on linear regression and the other based on the support vector machine (SVM). Using five-fold cross-validation, we confirmed the efficacy of our predictor.

  12. Relation between Cutting Surface Quality and Alloying Element Contents when Using a CO2 Laser

    Directory of Open Access Journals (Sweden)

    J. Litecká

    2011-01-01

    Full Text Available This paper deals with the influence of material content on changes in the quality parameters of the cutting surface when cutting with a laser. The study focuses on experiments to find the effect of material structure and cutting parameters on surface roughness, Vickers microhardness and precision of laser cutting. The experimental results are shown in graphs which illustrate the suitability of materials for achieving required cutting surface quality parameters. These results can be used for optimizing production in practical applications using a laser cutting machine.

  13. Automated Quality Assessment of Structural Magnetic Resonance Brain Images Based on a Supervised Machine Learning Algorithm

    Directory of Open Access Journals (Sweden)

    Ricardo Andres Pizarro

    2016-12-01

    Full Text Available High-resolution three-dimensional magnetic resonance imaging (3D-MRI is being increasingly used to delineate morphological changes underlying neuropsychiatric disorders. Unfortunately, artifacts frequently compromise the utility of 3D-MRI yielding irreproducible results, from both type I and type II errors. It is therefore critical to screen 3D-MRIs for artifacts before use. Currently, quality assessment involves slice-wise visual inspection of 3D-MRI volumes, a procedure that is both subjective and time consuming. Automating the quality rating of 3D-MRI could improve the efficiency and reproducibility of the procedure. The present study is one of the first efforts to apply a support vector machine (SVM algorithm in the quality assessment of structural brain images, using global and region of interest (ROI automated image quality features developed in-house. SVM is a supervised machine-learning algorithm that can predict the category of test datasets based on the knowledge acquired from a learning dataset. The performance (accuracy of the automated SVM approach was assessed, by comparing the SVM-predicted quality labels to investigator-determined quality labels. The accuracy for classifying 1457 3D-MRI volumes from our database using the SVM approach is around 80%. These results are promising and illustrate the possibility of using SVM as an automated quality assessment tool for 3D-MRI.

  14. Quality indexing by machine vision during fermentation in black tea manufacturing

    Science.gov (United States)

    Borah, S.; Bhuyan, M.

    2003-04-01

    Although the organoleptic method of tea testing has been traditionally used for quality monitoring, an alternative way by machine vision may be advantageous. Although, the three main quality descriptors estimate the overall quality of made-tea, viz., strength, briskness and brightness of tea liquor, the exact colour detection in fermenting process leads to a good quality-monitoring tool. The use of digital image processing technique for this purpose is reported to play an effective role towards the production of good quality tea though it is not the only quality determining parameter. In this paper, it has been tried to compare the contribution of the chemical constituents towards the final product with the visual appearance in the processing stage by imaging. The use of machine intelligence supports the process somewhat invariantly in comparison to the human decision and colorimetric approach. The captured images are processed for colour matching with a standard image database using HSI colour model. The application of colour dissimilarity and perceptron learning for the standard images and the test images is ensured. Moreover, the performance of the system is being tried to correlate with the decision made by the organoleptic panel assigned for the tea testing and chemical test results on the final product. However, it should be noted that the optimized result could be achieved only when the other quality parameters such as withering, flavour (aroma) detection, drying status etc. are properly maintained.

  15. Analytical modelling of modular and unequal tooth width surface-mounted permanent magnet machines

    OpenAIRE

    Li, G. J.; Zhu, Z-Q.

    2015-01-01

    This paper presents simple analytical modelling for 2 types of 3-phase surface-mounted permanent magnet (SPM) machines such as modular and unequal tooth width (UNET) machines with different slot/pole number combinations. It is based on the slotless open-circuit air-gap flux density and the slotted air-gap relative permeance calculations. This model allows calculating the open-circuit air-gap flux density, phase flux linkage and back electromotive force (EMF), average torque of both the modula...

  16. Rotary ultrasonic elliptical machining for side milling of CFRP: tool performance and surface integrity.

    Science.gov (United States)

    Geng, Daxi; Zhang, Deyuan; Xu, Yonggang; He, Fengtao; Liu, Dapeng; Duan, Zuoheng

    2015-05-01

    The rotary ultrasonic elliptical machining (RUEM) has been recognized as a new effective process to machining circular holes on CFRP materials. In CFRP face machining, the application of grinding tools is restricted for the tool clogging and the machined surface integrity. In this paper, we proposed a novel approach to extend the RUEM process to side milling of CFRP for the first time, which kept the effect of elliptical vibration in RUEM. The experiment apparatus was developed, and the preliminary experiments were designed and conducted, with comparison to conventional grinding (CG). The experimental results showed that when the elliptical vibration was applied in RUEM, a superior cutting process can be obtained compared with that in CG, including providing reduced cutting forces (2-43% decrement), an extended tool life (1.98 times), and improved surface integrity due to the intermittent material removal mechanism and the excellent chip removal conditions achieved in RUEM. It was concluded that the RUEM process is suitable to mill flat surface on CFRP composites.

  17. Machining Performance Study on Metal Matrix Composites-A Response Surface Methodology Approach

    Directory of Open Access Journals (Sweden)

    A. Srinivasan

    2012-01-01

    Full Text Available Problem statement: Metal Matrix Composites (MMC have become a leading material among composite materials and in particular, particle reinforced aluminum MMCs have received considerable attention due to their excellent engineering properties. These materials are known as the difficult-to-machine materials because of the hardness and abrasive nature of reinforcement element-like Alumina (Al2O3. Approach: In this study, an attempt has been made to model the machinability evaluation through the response surface methodology in machining of homogenized 10% micron Al2O3 LM25 Al MMC manufactured through stir casting method. Results: The combined effects of three machining parameters including cutting speed (s, feed rate (f and depth of cut (d on the basis of three performance characteristics of tool wear (VB, surface Roughness (Ra and cutting Force (Fz were investigated. The contour plots were generated to study the effect of process parameters as well as their interactions. Conclusion: The process parameters are optimized using desirability-based approach response surface methodology.

  18. A Method to Optimize Geometric Errors of Machine Tool based on SNR Quality Loss Function and Correlation Analysis

    Directory of Open Access Journals (Sweden)

    Cai Ligang

    2017-01-01

    Full Text Available Instead improving the accuracy of machine tool by increasing the precision of key components level blindly in the production process, the method of combination of SNR quality loss function and machine tool geometric error correlation analysis to optimize five-axis machine tool geometric errors will be adopted. Firstly, the homogeneous transformation matrix method will be used to build five-axis machine tool geometric error modeling. Secondly, the SNR quality loss function will be used for cost modeling. And then, machine tool accuracy optimal objective function will be established based on the correlation analysis. Finally, ISIGHT combined with MATLAB will be applied to optimize each error. The results show that this method is reasonable and appropriate to relax the range of tolerance values, so as to reduce the manufacturing cost of machine tools.

  19. Proceedings of the first workshop on Peripheral Machine Interfaces: Going beyond traditional surface electromyography

    Directory of Open Access Journals (Sweden)

    Claudio eCastellini

    2014-08-01

    Full Text Available One of the hottest topics in rehabilitation robotics is that of proper control of prosthetic devices. Despite decades of research, the state of the art is dramatically behind the expectations. To shed light on this issue, in June, 2013 the first international workshop on Present and future of non-invasive PNS-Machine Interfaces was convened, hosted by the International Conference on Rehabilitation Robotics. The keyword PNS-Machine Interface (PMI has been selected to denote human-machine interfaces targeted at the limb-deficient, mainly upper-limb amputees, dealing with signals gathered from the peripheral nervous system (PNS in a non-invasive way, that is, from the surface of the residuum. The workshop was intended to provide an overview of the state of the art and future perspectives of such interfaces; this paper represents is a collection of opinions expressed by each and every researcher/group involved in it.

  20. Improvement of Quality of a Modern Commercial Silk Mill through effective Process and Machine Control Parameters

    Directory of Open Access Journals (Sweden)

    Dr. Swapan Kumar Ghosh

    2016-08-01

    Full Text Available This paper deals with international and national scenario of commercial production and market share of silk fabrics with particular reference to process along with machine control parameters followed by adoption of good practices in the preparatory stages during production of the silk fabric in a commercial Silk Mill. An observatory report has been presented here for starting from yarn to the fabric stage, which indicates the major technical reasons for deterioration in the quality of the silk products affecting the cost factor and environment to some extent. This paper delineates an effective monitoring and controlling process variables along with machine parameters at every step of production of silk fabric from its filament yarn stage, particularly during the modern high speed silk twisting process, enhancing the quality of the finished product on one hand and minimizing wastage along with the cost of production and adverse environmental impact on the other

  1. Machine integrated optical measurement of honed surfaces in presence of cooling lubricant

    Science.gov (United States)

    Schmitt, R.; König, N.; Zheng, H.

    2011-08-01

    The measurement of honed surfaces is one of the most important tasks in tribology. Although many established techniques exist for texture characterization, such as SEM, tactile stylus or white-light interferometry, none of them is suited for a machine integrated measurement. Harsh conditions such as the presence of cooling lubricant or vibrations prohibit the use of commercial sensors inside a honing machine. Instead, machined engine blocks need time-consuming cleaning and preparation while taken out of the production line for inspection. A full inspection of all produced parts is hardly possible this way. Within this paper, an approach for a machine-integrated measurement is presented, which makes use of optical sensors for texture profiling. The cooling lubricant here serves as immersion medium. The results of test measurements with a chromatic-confocal sensor and a fiber-optical low-coherence interferometer show the potential of both measuring principles for our approach. Cooling lubricant temperature and flow, scanning speed and measurement frequency have been varied in the tests. The sensor with best performance will later be chosen for machine integration.

  2. Machine integrated optical measurement of honed surfaces in presence of cooling lubricant

    Energy Technology Data Exchange (ETDEWEB)

    Schmitt, R; Koenig, N; Zheng, H, E-mail: n.koenig@wzl.rwth-aachen.de [Laboratory for Machine Tools and Production Engineering of RWTH Aachen University, Steinbachstr. 19, 52074 Aachen (Germany)

    2011-08-19

    The measurement of honed surfaces is one of the most important tasks in tribology. Although many established techniques exist for texture characterization, such as SEM, tactile stylus or white-light interferometry, none of them is suited for a machine integrated measurement. Harsh conditions such as the presence of cooling lubricant or vibrations prohibit the use of commercial sensors inside a honing machine. Instead, machined engine blocks need time-consuming cleaning and preparation while taken out of the production line for inspection. A full inspection of all produced parts is hardly possible this way. Within this paper, an approach for a machine-integrated measurement is presented, which makes use of optical sensors for texture profiling. The cooling lubricant here serves as immersion medium. The results of test measurements with a chromatic-confocal sensor and a fiber-optical low-coherence interferometer show the potential of both measuring principles for our approach. Cooling lubricant temperature and flow, scanning speed and measurement frequency have been varied in the tests. The sensor with best performance will later be chosen for machine integration.

  3. SURFACE WATER QUALITY IN THE RIVER PRUT

    Directory of Open Access Journals (Sweden)

    MIHAELA DUMITRAN

    2011-03-01

    Full Text Available Water is an increasingly important and why it is important to surfacewater quality, which is given by the analysis of physical - chemical, biological andobserving the investigation of water, biota, environments investigation. Analysis ofthe Prut river in terms of biological and physical elements - chemical. Evaluationof ecological and chemical status of water was done according to order of approvalof the standard classification nr.161/2006 surface water to determine the ecologicalstatus of water bodies

  4. Drinking Water Quality of Water Vending Machines in Parit Raja, Batu Pahat, Johor

    Science.gov (United States)

    Hashim, N. H.; Yusop, H. M.

    2016-07-01

    An increased in demand from the consumer due to their perceptions on tap water quality is identified as one of the major factor on why they are mentally prepared to pay for the price of the better quality drinking water. The thought that filtered water quality including that are commercially available in the market such as mineral and bottled drinking water and from the drinking water vending machine makes they highly confident on the level of hygiene, safety and the mineral content of this type of drinking water. This study was investigated the vended water quality from the drinking water vending machine in eight locations in Parit Raja are in terms of pH, total dissolve solids (TDS), turbidity, mineral content (chromium, arsenic, cadmium, lead and nickel), total organic carbon (TOC), pH, total colony-forming units (CFU) and total coliform. All experiments were conducted in one month duration in triplicate samples for each sampling event. The results indicated the TDS and all heavy metals in eight vended water machines in Parit Raja area were found to be below the Food Act 1983, Regulation 360C (Standard for Packaged Drinking Water and Vended water, 2012) and Malaysian Drinking Water Quality, Ministry of Health 1983. No coliform was presence in any of the vended water samples. pH was found to be slightly excess the limit provided while turbidity was found to be 45 to 95 times more higher than 0.1 NTU as required by the Malaysian Food Act Regulation. The data obtained in this study would suggest the important of routine maintenance and inspection of vended water provider in order to maintain a good quality, hygienic and safety level of vended water.

  5. Effect of Ceramic Surface Treatments After Machine Grinding on the Biaxial Flexural Strength of Different CAD/CAM Dental Ceramics

    Science.gov (United States)

    Bagheri, Hossein; Aghajani, Farzaneh

    2015-01-01

    Objectives: This study aimed to evaluate the effect of different ceramic surface treatments after machining grinding on the biaxial flexural strength (BFS) of machinable dental ceramics with different crystalline phases. Materials and Methods: Disk-shape specimens (10mm in diameter and 1.3mm in thickness) of machinable ceramic cores (two silica-based and one zirconia-based ceramics) were prepared. Each type of the ceramic surfaces was then randomly treated (n=15) with different treatments as follows: 1) machined finish as control, 2) machined finish and sandblasting with alumina, and 3) machined finish and hydrofluoric acid etching for the leucite and lithium disilicate-based ceramics, and for the zirconia; 1) machined finish and post-sintered as control, 2) machined finish, post-sintered, and sandblasting, and 3) machined finish, post-sintered, and Nd;YAG laser irradiation. The BFS were measured in a universal testing machine. Data based were analyzed by ANOVA and Tukey’s multiple comparisons post-hoc test (α=0.05). Results: The mean BFS of machined finish only surfaces for leucite ceramic was significantly higher than that of sandblasted (P=0.001) and acid etched surfaces (P=0.005). A significantly lower BFS was found after sandblasting for lithium disilicate compared with that of other groups (P<0.05). Sandblasting significantly increased the BFS for the zirconia (P<0.05), but the BFS was significantly decreased after laser irradiation (P<0.05). Conclusions: The BFS of the machinable ceramics was affected by the type of ceramic material and surface treatment method. Sandblasting with alumina was detrimental to the strength of only silica-based ceramics. Nd:YAG laser irradiation may lead to substantial strength degradation of zirconia. PMID:27148372

  6. Potential application of machine vision technology to saffron (Crocus sativus L.) quality characterization.

    Science.gov (United States)

    Kiani, Sajad; Minaei, Saeid

    2016-12-01

    Saffron quality characterization is an important issue in the food industry and of interest to the consumers. This paper proposes an expert system based on the application of machine vision technology for characterization of saffron and shows how it can be employed in practical usage. There is a correlation between saffron color and its geographic location of production and some chemical attributes which could be properly used for characterization of saffron quality and freshness. This may be accomplished by employing image processing techniques coupled with multivariate data analysis for quantification of saffron properties. Expert algorithms can be made available for prediction of saffron characteristics such as color as well as for product classification.

  7. Shape correction of optical surfaces using plasma chemical vaporization machining with a hemispherical tip electrode.

    Science.gov (United States)

    Takino, Hideo; Yamamura, Kazuya; Sano, Yasuhisa; Mori, Yuzo

    2012-01-20

    We propose a plasma chemical vaporization machining device with a hemispherical tip electrode for optical fabrication. Radio-frequency plasma is generated close to the electrode under atmospheric conditions, and a workpiece is scanned relative to the stationary electrode under three-axis motion control to remove target areas on a workpiece surface. Experimental results demonstrate that surface removal progresses although process gas is not forcibly supplied to the plasma. The correction of shape errors on conventionally polished spheres is performed. As a result, highly accurate smooth surfaces with the desired rms shape accuracy of 3 nm are successfully obtained, which confirms that the device is effective for the fabrication of optics.

  8. Surface Characteristics of Machined NiTi Shape Memory Alloy: The Effects of Cryogenic Cooling and Preheating Conditions

    Science.gov (United States)

    Kaynak, Y.; Huang, B.; Karaca, H. E.; Jawahir, I. S.

    2017-07-01

    This experimental study focuses on the phase state and phase transformation response of the surface and subsurface of machined NiTi alloys. X-ray diffraction (XRD) analysis and differential scanning calorimeter techniques were utilized to measure the phase state and the transformation response of machined specimens, respectively. Specimens were machined under dry machining at ambient temperature, preheated conditions, and cryogenic cooling conditions at various cutting speeds. The findings from this research demonstrate that cryogenic machining substantially alters austenite finish temperature of martensitic NiTi alloy. Austenite finish ( A f) temperature shows more than 25 percent increase resulting from cryogenic machining compared with austenite finish temperature of as-received NiTi. Dry and preheated conditions do not substantially alter austenite finish temperature. XRD analysis shows that distinctive transformation from martensite to austenite occurs during machining process in all three conditions. Complete transformation from martensite to austenite is observed in dry cutting at all selected cutting speeds.

  9. Polymer micromolds with near optical quality surface finishes

    Science.gov (United States)

    Shiu, Pun-Pang; Knopf, George K.; Nikumb, Suwas

    2012-03-01

    Disposable microfluidic systems are used to avoid sample contamination in a variety of medical and environmental monitoring applications. A contactless hot intrusion (HI) process for fabricating reusable polymer micromolds with near "optical quality" surface finishes is described in this paper. A metallic hot intrusion mask with the desired microchannels and related passive components is first machined using a tightly focused beam from a diode-pumped solid-state (DPSS) laser. The polymer mold master is then created by pressing the 2D metallic mask onto a polymethylmethacrylate (PMMA) substrate. Since it is a contactless fabrication process the resultant 3D micro-reliefs have near optical quality surface finishes. Unfortunately, the desired micro-relief dimensions (height and width) are not easily related to the hot intrusion process parameters of pressure, temperature, and time exposure profile. A finite element model is introduced to assist the manufacturing engineer in predicting the behavior of the PMMA substrate material as it deforms under heat and pressure during micromold manufacture. The FEM model assumes that thermo-plastics like PMMA become "rubber like" when heated to a temperature slightly above the glass transition temperature. By controlling the material temperature and maintaining its malleable state, it is possible to use the stress-strain relationship to predict the profile dimensions of the imprinted microfeature. Examples of curved microchannels fabricated using PMMA mold masters are presented to illustrate the proposed methodology and verify the finite element model. In addition, the non-contact formation of the micro-reliefs simplifies the demolding process and helps to preserve the high quality surface finishes.

  10. Processing and Characterization of Novel Biomimetic Nanoporous Bioceramic Surface on β-Ti Implant by Powder Mixed Electric Discharge Machining

    Science.gov (United States)

    Prakash, Chander; Kansal, H. K.; Pabla, B. S.; Puri, Sanjeev

    2015-09-01

    Herein, a β-Ti-based implant was subjected to powder mixed electric discharge machining (PMEDM) for surface modification to produce a novel biomimetic nanoporous bioceramic surface. The microstructure, surface topography, and phase composition of the non-machined and machined (PMEDMed) surfaces were investigated using field-emission scanning electron microscopy, energy-dispersive x-ray spectroscopy, and x-ray diffraction. The microhardness of the surfaces was measured on a Vickers hardness tester. The corrosion resistance of the surfaces was evaluated via potentiodynamic polarization measurements in simulated body fluid. The application of PMEDM not only altered the surface chemistry, but also imparted the surface with a nanoporous topography or a natural bone-like surface structure. The characterization results confirmed that the alloyed layer mainly comprised bioceramic oxides and carbide phases (TiO2, Nb2O5, ZrO2, SiO2, TiC, NbC, SiC). The microhardness of PMEDMed surface was twofold higher than that of the base material (β-Ti alloy), primarily because of the formation of the hard carbide phases on the machined layer. Electrochemical analysis revealed that PMEDMed surface featured insulative and protective properties and thus displayed higher corrosion resistance ability when compared with the non-machined surface. This result was attributed to the formation of the bioceramic oxides on the machined surface. Additionally, the in vitro biocompatibility of the surfaces was evaluated using human osteoblastic cell line MG-63. PMEDMed surface with a micro-, sub-micro-, and nano-structured topography exhibited bioactivity and improved biocompatibility relative to β-Ti surface. Furthermore, PMEDMed surface enabled better adhesion and growth of MG-63 when compared with the non-machined substrate.

  11. A planning quality evaluation tool for prostate adaptive IMRT based on machine learning

    Energy Technology Data Exchange (ETDEWEB)

    Zhu Xiaofeng; Ge Yaorong; Li Taoran; Thongphiew, Danthai; Yin Fangfang; Wu, Q Jackie [Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina 27708 (United States); Department of Biomedical Engineering, Wake Forest University Health Sciences, Medical Center Boulevard, Winston-Salem, North Carolina 27106 (United States); Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina 27708 (United States); Department of Radiation Oncology, Brody School of Medicine, East Carolina University, Greenville, North Carolina 27834 (United States); Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina 27708 (United States)

    2011-02-15

    Purpose: To ensure plan quality for adaptive IMRT of the prostate, we developed a quantitative evaluation tool using a machine learning approach. This tool generates dose volume histograms (DVHs) of organs-at-risk (OARs) based on prior plans as a reference, to be compared with the adaptive plan derived from fluence map deformation. Methods: Under the same configuration using seven-field 15 MV photon beams, DVHs of OARs (bladder and rectum) were estimated based on anatomical information of the patient and a model learned from a database of high quality prior plans. In this study, the anatomical information was characterized by the organ volumes and distance-to-target histogram (DTH). The database consists of 198 high quality prostate plans and was validated with 14 cases outside the training pool. Principal component analysis (PCA) was applied to DVHs and DTHs to quantify their salient features. Then, support vector regression (SVR) was implemented to establish the correlation between the features of the DVH and the anatomical information. Results: DVH/DTH curves could be characterized sufficiently just using only two or three truncated principal components, thus, patient anatomical information was quantified with reduced numbers of variables. The evaluation of the model using the test data set demonstrated its accuracy {approx}80% in prediction and effectiveness in improving ART planning quality. Conclusions: An adaptive IMRT plan quality evaluation tool based on machine learning has been developed, which estimates OAR sparing and provides reference in evaluating ART.

  12. Electrochemical machining process for forming surface roughness elements on a gas turbine shroud

    Science.gov (United States)

    Lee, Ching-Pang; Johnson, Robert Alan; Wei, Bin; Wang, Hsin-Pang

    2002-01-01

    The back side recessed cooling surface of a shroud defining in part the hot gas path of a turbine is electrochemically machined to provide surface roughness elements and spaces therebetween to increase the heat transfer coefficient. To accomplish this, an electrode with insulating dielectric portions and non-insulating portions is disposed in opposition to the cooling surface. By passing an electrolyte between the cooling surface and electrode and applying an electrical current between the electrode and a shroud, roughness elements and spaces therebetween are formed in the cooling surface in opposition to the insulating and non-insulating portions of the electrode, hence increasing the surface area and heat transfer coefficient of the shroud.

  13. Microstructural Analysis of Machined Surface Integrity in Drilling a Titanium Alloy

    Science.gov (United States)

    Varote, Nilesh; Joshi, Suhas S.

    2017-08-01

    Severe mechanical deformation coupled with high heat generation prevails during drilling. Establishing correlations between microstructure and surface integrity has always been a challenge, which is the main focus of this work. High-speed drilling experiments were performed by varying speed, feed rate and machining environments (dry and wet). The changes in microhardness, residual stresses and microstructure on the drilled surfaces were analyzed. A dominant mechanical deformation is found to lower grain size and increase grain boundary misorientation angle, whereas under a dominant thermal deformation higher grain size and lower grain boundary misorientation angle was evident. In dry drilling, a combined effect of temperature and mechanical deformation, the deformed and then recrystallized grains are observed to have < {0001} \\rangle orientation. The drilling parameters that increase strain rate aggravate machining-affected zone, whereas heat accumulation increases heat-affected zone, only in dry drilling. An empirical model for predicting grain size has been developed.

  14. Microstructure & performance of laser cladding on pick surface of coal mining machine

    Institute of Scientific and Technical Information of China (English)

    SUN Hui-lai; ZHAO Fang-fang; ZHANG Shou-xin; QI Xiang-yang

    2006-01-01

    Laser cladding of 316 L steel powders on pick substrate of coal mining machine was conducted, and microstructure of laser cladding coating was analyzed. The micro-hardness of laser cladding coating was examined. The results show that microstructure of laser cladding zone is exiguous dentrite, and there are hard spots dispersible distribution in the laser cladding zone. Performances of erode-resistant, surface micro-hardness and wear-resistant are improved obviously.

  15. Impact of machines on plan quality: volumetric modulated arc therapy and intensity modulated radiation therapy.

    Science.gov (United States)

    Clemente, S; Cozzolino, M; Oliviero, C; Fiorentino, A; Chiumento, C; Fusco, V

    2014-02-01

    To evaluate the impact of different machines on plan quality using both intensity modulated radiation therapy (IMRT) and volumetric-modulated arc therapy (VMAT) techniques. Eight patients with squamous cell carcinoma of the oropharynx were selected at random. Plans were computed for IMRT and VMAT Smart Arc, using Pinnacle TPS for an Elekta (IMRT-E, VMAT-E) and Varian linac (IMRT-V, VMAT-V). A three-dose level prescription was used to deliver 70, 63 and 58.1 Gy to regions of macroscopic, microscopic high- and low-risk disease, respectively. All doses were given in 35 fractions. Comparisons were performed on dose-volume histogram data, monitor units (MU), and delivery time. VMAT-E plans resulted slightly MU efficient (-24 % p delivery time (-19 % p < 0.05) compared to IMRT-E. All the delivery techniques resulted in equivalent target coverage in terms of D(98) % and D(2) %. For VMAT technique, a significant improvement of 7 % in homogeneity index (HI) for PTV58.1 was observed for Varian machine. A slight improvement in OARs sparing was observed with Elekta machine both for IMRT and VMAT techniques. Similar plan quality was observed for Elekta and Varian linacs, significant differences were observed in delivery efficiency, as MU number and delivery times, in favor of Elekta and Varian, respectively.

  16. Artificial immune algorithm implementation for optimized multi-axis sculptured surface CNC machining

    Science.gov (United States)

    Fountas, N. A.; Kechagias, J. D.; Vaxevanidis, N. M.

    2016-11-01

    This paper presents the results obtained by the implementation of an artificial immune algorithm to optimize standard multi-axis tool-paths applied to machine free-form surfaces. The investigation for its applicability was based on a full factorial experimental design addressing the two additional axes for tool inclination as independent variables whilst a multi-objective response was formulated by taking into consideration surface deviation and tool path time; objectives assessed directly from computer-aided manufacturing environment A standard sculptured part was developed by scratch considering its benchmark specifications and a cutting-edge surface machining tool-path was applied to study the effects of the pattern formulated when dynamically inclining a toroidal end-mill and guiding it towards the feed direction under fixed lead and tilt inclination angles. The results obtained form the series of the experiments were used for the fitness function creation the algorithm was about to sequentially evaluate. It was found that the artificial immune algorithm employed has the ability of attaining optimal values for inclination angles facilitating thus the complexity of such manufacturing process and ensuring full potentials in multi-axis machining modelling operations for producing enhanced CNC manufacturing programs. Results suggested that the proposed algorithm implementation may reduce the mean experimental objective value to 51.5%

  17. Generalization Evaluation of Machine Learning Numerical Observers for Image Quality Assessment.

    Science.gov (United States)

    Kalayeh, Mahdi M; Marin, Thibault; Brankov, Jovan G

    2013-06-01

    In this paper, we present two new numerical observers (NO) based on machine learning for image quality assessment. The proposed NOs aim to predict human observer performance in a cardiac perfusion-defect detection task for single-photon emission computed tomography (SPECT) images. Human observer (HumO) studies are now considered to be the gold standard for task-based evaluation of medical images. However such studies are impractical for use in early stages of development for imaging devices and algorithms, because they require extensive involvement of trained human observers who must evaluate a large number of images. To address this problem, numerical observers (also called model observers) have been developed as a surrogate for human observers. The channelized Hotelling observer (CHO), with or without internal noise model, is currently the most widely used NO of this kind. In our previous work we argued that development of a NO model to predict human observers' performance can be viewed as a machine learning (or system identification) problem. This consideration led us to develop a channelized support vector machine (CSVM) observer, a kernel-based regression model that greatly outperformed the popular and widely used CHO. This was especially evident when the numerical observers were evaluated in terms of generalization performance. To evaluate generalization we used a typical situation for the practical use of a numerical observer: after optimizing the NO (which for a CHO might consist of adjusting the internal noise model) based upon a broad set of reconstructed images, we tested it on a broad (but different) set of images obtained by a different reconstruction method. In this manuscript we aim to evaluate two new regression models that achieve accuracy higher than the CHO and comparable to our earlier CSVM method, while dramatically reducing model complexity and computation time. The new models are defined in a Bayesian machine-learning framework: a channelized

  18. An e-quality control model for multistage machining processes of workpieces

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    To track and control the changes of process quality attributes in multistage machining processes(MMPs),an e-quality control(e-QC) model is proposed.The e-QC model is defined as a quality information service node with e-formalizing technology,whose input/output and intermediate process(that is IPO) are known to other nodes,and its implemention in MMPs is provided.In order to establish the e-QC model,a measuring network is constructed to acquire the original quality data,and the changes of process quality attributes are monitored and diagnosed by the integrated quality analysis tools attached to the e-QC,which can be tracked by information template network in real time.Furthermore,a hierarchical control method is adopted to coordinate e-QCs,in which the quality loss and adjusting cost are used to quantify the opportunities for e-QCs to improve process quality.At last,a prototype is developed to verify the proposed methods.

  19. An e-quality control model for multistage machining processes of workpieces

    Institute of Scientific and Technical Information of China (English)

    LIU DaoYu; JIANG PingYu; ZHANG YingFeng

    2008-01-01

    To track and control the changes of process quality attributes in multistage ma-chining processes (MMPs), an e-quality control (e-QC) model is proposed. The e-QC model is defined as a quality information service node with e-formalizing technology, whose input/output and intermediate process (that is IPO) are known to other nodes, and its implemention in MMPs is provided. In order to establish the e-QC model, a measuring network is constructed to acquire the original quality data, and the changes of process quality attributes are monitored and diagnosed by the integrated quality analysis tools attached to the e-QC, which can be tracked by in-formation template network in real time. Furthermore, a hierarchical control method is adopted to coordinate e-QCs, in which the quality loss and adjusting cost are used to quantify the opportunities for e-QCs to improve process quality. At last, a prototype is developed to verify the proposed methods.

  20. DIAGNOSTICS OF WORKPIECE SURFACE CONDITION BASED ON CUTTING TOOL VIBRATIONS DURING MACHINING

    Directory of Open Access Journals (Sweden)

    Jerzy Józwik

    2015-05-01

    Full Text Available The paper presents functional relationships between surface geometry parameters, feed and vibrations level in the radial direction of the workpiece. Time characteristics of the acceleration of cutting tool vibration registered during C45 steel and stainless steel machining for separate axes (X, Y, Z were presented as a function of feedrate f. During the tests surface geometric accuracy assessment was performed and 3D surface roughness parameters were determined. The Sz parameter was selected for the analysis, which was then collated with RMS vibration acceleration and feedrate f. The Sz parameter indirectly provides information on peak to valley height and is characterised by high generalising potential i.e. it is highly correlated to other surface and volume parameters of surface roughness. Test results presented in this paper may constitute a valuable source of information considering the influence of vibrations on geometric accuracy of elements for engineers designing technological processes.

  1. Inner surface roughness of complete cast crowns made by centrifugal casting machines.

    Science.gov (United States)

    Ogura, H; Raptis, C N; Asgar, K

    1981-05-01

    Six variables that could affect the surface roughness of a casting were investigated. The variables were (1) type of alloy, (2) mold temperature, (3) metal casting temperature, (4) casting machine, (5) sandblasting, and (6) location of each section. It was determined that the training portion of a complete cast crown had rougher surfaces than the leading portion. Higher mold and casting temperatures produced rougher castings, and this effect was more pronounced in the case of the base metal alloy. Sandblasting reduced the roughness, but produced scratched surfaces. Sandblasting had a more pronounced affect on the surface roughness of the base metal alloy cast either at a higher mold temperature or metal casting temperature. The morphology and the roughness profile of the original cast surface differed considerably with the type of alloy used.

  2. Fabrication quality analysis of a fiber optic refractive index sensor created by CO2 laser machining.

    Science.gov (United States)

    Chen, Chien-Hsing; Yeh, Bo-Kuan; Tang, Jaw-Luen; Wu, Wei-Te

    2013-03-26

    This study investigates the CO2 laser-stripped partial cladding of silica-based optic fibers with a core diameter of 400 μm, which enables them to sense the refractive index of the surrounding environment. However, inappropriate treatments during the machining process can generate a number of defects in the optic fiber sensors. Therefore, the quality of optic fiber sensors fabricated using CO2 laser machining must be analyzed. The results show that analysis of the fiber core size after machining can provide preliminary defect detection, and qualitative analysis of the optical transmission defects can be used to identify imperfections that are difficult to observe through size analysis. To more precisely and quantitatively detect fabrication defects, we included a tensile test and numerical aperture measurements in this study. After a series of quality inspections, we proposed improvements to the existing CO2 laser machining parameters, namely, a vertical scanning pathway, 4 W of power, and a feed rate of 9.45 cm/s. Using these improved parameters, we created optical fiber sensors with a core diameter of approximately 400 μm, no obvious optical transmission defects, a numerical aperture of 0.52 ± 0.019, a 0.886 Weibull modulus, and a 1.186 Weibull-shaped parameter. Finally, we used the optical fiber sensor fabricated using the improved parameters to measure the refractive indices of various solutions. The results show that a refractive-index resolution of 1.8 × 10(-4) RIU (linear fitting R2 = 0.954) was achieved for sucrose solutions with refractive indices ranging between 1.333 and 1.383. We also adopted the particle plasmon resonance sensing scheme using the fabricated optical fibers. The results provided additional information, specifically, a superior sensor resolution of 5.73 × 10(-5) RIU, and greater linearity at R2 = 0.999.

  3. Response surface modelling of tool electrode wear rate and material removal rate in micro electrical discharge machining of Inconel 718

    DEFF Research Database (Denmark)

    Puthumana, Govindan

    2017-01-01

    conductivity and high strength causing it extremely difficult tomachine. Micro-Electrical Discharge Machining (Micro-EDM) is a non-conventional method that has a potential toovercome these restrictions for machining of Inconel 718. Response Surface Method (RSM) was used for modelling thetool Electrode Wear...

  4. Effect of machining conditions on MRR and surface roughness during CNC Turning of different Materials Using TiN Coated Cutting Tools – A Taguchi approach

    Directory of Open Access Journals (Sweden)

    H. K. Raval

    2012-10-01

    Full Text Available This paper presents on experimental investigation of the machining characteristics of different grades of EN materials in CNC turning process using TiN coated cutting tools. In machining operation, the quality of surface finish is an important requirement for many turned work pieces. Thus, the choice of optimized cutting parameters is very important for controlling the required surface quality. The purpose of this research paper is focused on the analysis of optimum cutting conditions to get the lowest surface roughness and maximum material removal rate in CNC turning of different grades of EN materials by Taguchi method. Optimal cutting parameters for each performance measure were obtained employing Taguchi techniques. The orthogonal array, signal to noise ratio and analysis of variance were employed to study the performance characteristics in dry turning operation. ANOVA has shown that the depth of cut has significant role to play in producing higher MRR and insert has significant role to play for producing lower surface roughness. Thus, it is possible to increase machine utilization and decrease production cost in an automated manufacturing environment.

  5. Controlling the Adhesion of Superhydrophobic Surfaces Using Electrolyte Jet Machining Techniques

    Science.gov (United States)

    Yang, Xiaolong; Liu, Xin; Lu, Yao; Zhou, Shining; Gao, Mingqian; Song, Jinlong; Xu, Wenji

    2016-04-01

    Patterns with controllable adhesion on superhydrophobic areas have various biomedical and chemical applications. Electrolyte jet machining technique (EJM), an electrochemical machining method, was firstly exploited in constructing dimples with various profiles on the superhydrophobic Al alloy surface using different processing parameters. Sliding angles of water droplets on those dimples firstly increased and then stabilized at a certain value with the increase of the processing time or the applied voltages of the EJM, indicating that surfaces with different adhesion force could be obtained by regulating the processing parameters. The contact angle hysteresis and the adhesion force that restricts the droplet from sliding off were investigated through experiments. The results show that the adhesion force could be well described using the classical Furmidge equation. On account of this controllable adhesion force, water droplets could either be firmly pinned to the surface, forming various patterns or slide off at designed tilting angles at specified positions on a superhydrophobic surface. Such dimples on superhydrophopbic surfaces can be applied in water harvesting, biochemical analysis and lab-on-chip devices.

  6. Uniform surface polished method of complex holes in abrasive flow machining

    Institute of Scientific and Technical Information of China (English)

    A-Cheng WANG; Lung TSAI; Kuo-Zoo LIANG; Chun-Ho LIU; Shi-Hong WENG

    2009-01-01

    Abrasive flow machining(AFM) is an effective method that can remove the recasting layer produced by wire electrical discharge machining(WEDM). However, the surface roughness will not be easily uniform when a complex hole is polished by this method. CFD numerical method is aided to design good passageways to find the smooth roughness on the complex hole in AFM. Through the present method, it reveals that the shear forces in the polishing process and the flow properties of the medium in AFM play the roles in controlling the roughness on the entire surface. A power law model was firstly set up by utilizing the effect of shear rates on the medium viscosities, and the coefficients of the power law would be found by solving the algebraic equation from the relations between the shear rates and viscosities. Then the velocities, strain rates and shear forces of the medium acting on the surface would be obtained in the constant pressure by CFD software. Finally, the optimal mold core put into the complex hole could be designed after these simulations. The results show that the shear forces and strain rates change sharply on the entire surface if no mold core is inserted into the complex hole, whereas they hardly make any difference when the core shape is similar to the complex hole. Three experimental types of mold core were used. The results demonstrate that the similar shape of the mold core inserted into the hole could find the uniform roughness on the surface.

  7. Controlling the Adhesion of Superhydrophobic Surfaces Using Electrolyte Jet Machining Techniques.

    Science.gov (United States)

    Yang, Xiaolong; Liu, Xin; Lu, Yao; Zhou, Shining; Gao, Mingqian; Song, Jinlong; Xu, Wenji

    2016-04-05

    Patterns with controllable adhesion on superhydrophobic areas have various biomedical and chemical applications. Electrolyte jet machining technique (EJM), an electrochemical machining method, was firstly exploited in constructing dimples with various profiles on the superhydrophobic Al alloy surface using different processing parameters. Sliding angles of water droplets on those dimples firstly increased and then stabilized at a certain value with the increase of the processing time or the applied voltages of the EJM, indicating that surfaces with different adhesion force could be obtained by regulating the processing parameters. The contact angle hysteresis and the adhesion force that restricts the droplet from sliding off were investigated through experiments. The results show that the adhesion force could be well described using the classical Furmidge equation. On account of this controllable adhesion force, water droplets could either be firmly pinned to the surface, forming various patterns or slide off at designed tilting angles at specified positions on a superhydrophobic surface. Such dimples on superhydrophopbic surfaces can be applied in water harvesting, biochemical analysis and lab-on-chip devices.

  8. Surface Roughness Prediction Model in Machining of Carbon Steel by PVD Coated Cutting Tools

    Directory of Open Access Journals (Sweden)

    Yusuf Sahin

    2004-01-01

    Full Text Available The surface roughness model in the turning of AISI 1040 carbon steel was developed in terms of cutting speed, feed rate and depth of cut using response surface methodology. Machining tests were carried out using PVD-coated tools under different cutting conditions. The surface roughness equations of cutting tools when machining the carbon steels were achieved by using the experimental data. The results are presented in terms of mean values and confidence levels. The established equation shows that the feed rate was found to be a main influencing factor on the surface roughness. It increased with increasing the feed rate, but decreased with increasing the cutting speed and the depth of cut, respectively. The variance analysis for the second-order model shows that the interaction terms and the square terms were statically insignificant. However, it could be seen that the first-order effect of feed rate was significant while cutting speed and depth of cut was insignificant. The predicted surface roughness of the samples was found to lie close to that of the experimentally observed ones with 95% confident intervals.

  9. Application Research on Powder Mixed EDM in Rough Machining

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Powder Mixed Electric Discharge Machining (PMEDM) has different mechanism from conventional EDM, which can improve the surface roughness and surface quality distinctly and to obtain nearly mirror surface effects. It is a useful finish machining method and is researched and applied by many countries. However there are little research on rough machining of PMEDM. Experiments show that PMEDM machining makes discharge breakdown easier, enlarges the discharge gaps and widens discharge passage, and at last form...

  10. Optimizing the Machining Parameters for Minimum Surface Roughness in Turning of GFRP Composites Using Design of Experiments

    Institute of Scientific and Technical Information of China (English)

    K. Palanikumar; L.Karunamoorthy; R.Karthikeyan

    2004-01-01

    In recent years, glass fiber reinforced plastics (GFRP) are being extensively used in variety of engineering applications in many different fields such as aerospace, oil, gas and process industries. However, the users of FRP are facing difficulties to machine it, because of fiber delamination, fiber pull out, short tool life, matrix debonding, burning and formation of powder like chips. The present investigation focuses on the optimization of machining parameters for surface roughness of glass fiber reinforced plastics (GFRP) using design of experiments (DoE). The machining parameters considered were speed, feed, depth of cut and workpiece (fiber orientation). An attempt was made to analyse the influence of factors and their interactions during machining. The results of the present study gives the optimal combination of machining parameters and this will help to improve the machining requirements of GFRP composites.

  11. DECREASING HEAT TREATMENT COST OF SURFACE HARDENED MACHINE PARTS BY CASE CARBURIZATION

    Directory of Open Access Journals (Sweden)

    Ahmet Çetin CAN

    1997-03-01

    Full Text Available Machine parts are surface hardened to increase fatigue strength and wear resistance. Carburization is the most common surface hardening process in practice. In order to have optimum properties, a machine part must have certain hardness depth. To obtain required hardness depth, the parts must be kept in a carburizing medium at certain temperature for certain time. As the time and temperature is increased hardness depth increases. In practice, carburization temperature is about 930 °C. Machine parts are kept at this temperature for required time depending on required hardness depth. The increase of temperature reduces treatment time, considerably. But, heat treaters do not tend to use high temperatures due to the concern of distortion of parts, and deterioration of mechanical properties. In this study, the increase of temperature for reducing carburization time in salt bath, and consequently change of mechanical properties have been investigated using DIN C20 case carburization steel. As a result of experiments, it was found that mechanical properties were not effected negatively.

  12. Development of an automatic weld surface appearance inspection system using machine vision

    Institute of Scientific and Technical Information of China (English)

    Lin Sanbao; Fu Xibin; Fan Chenglei; Yang Chunli; Luo Lu

    2009-01-01

    In this paper, an automatic inspection system for weld surface appearance using machine vision has been developed to recognize weld surface defects such as porosities, cracks, etc. It can replace conventional manual visual inspection method, which is tedious, time-consuming, subjective, experience-depended, and sometimes biased. The system consists of a CCD camera, a self-designed annular light source, a sensor controller, a frame grabbing card, a computer and so on. After acquiring weld surface appearance images using CCD, the images are preprocessed using median filtering and a series of image enhancement algorithms. Then a dynamic threshold and morphology algorithms are applied to segment defect object. Finally, defect features information is obtained by eight neighborhoods boundary chain code algorithm. Experimental results show that the developed system is capable of inspecting most surface defects such as porosities, cracks with high reliability and accuracy.

  13. Proceedings of the first workshop on Peripheral Machine Interfaces: going beyond traditional surface electromyography.

    Science.gov (United States)

    Castellini, Claudio; Artemiadis, Panagiotis; Wininger, Michael; Ajoudani, Arash; Alimusaj, Merkur; Bicchi, Antonio; Caputo, Barbara; Craelius, William; Dosen, Strahinja; Englehart, Kevin; Farina, Dario; Gijsberts, Arjan; Godfrey, Sasha B; Hargrove, Levi; Ison, Mark; Kuiken, Todd; Marković, Marko; Pilarski, Patrick M; Rupp, Rüdiger; Scheme, Erik

    2014-01-01

    One of the hottest topics in rehabilitation robotics is that of proper control of prosthetic devices. Despite decades of research, the state of the art is dramatically behind the expectations. To shed light on this issue, in June, 2013 the first international workshop on Present and future of non-invasive peripheral nervous system (PNS)-Machine Interfaces (MI; PMI) was convened, hosted by the International Conference on Rehabilitation Robotics. The keyword PMI has been selected to denote human-machine interfaces targeted at the limb-deficient, mainly upper-limb amputees, dealing with signals gathered from the PNS in a non-invasive way, that is, from the surface of the residuum. The workshop was intended to provide an overview of the state of the art and future perspectives of such interfaces; this paper represents is a collection of opinions expressed by each and every researcher/group involved in it.

  14. Proceedings of the first workshop on Peripheral Machine Interfaces: going beyond traditional surface electromyography

    Science.gov (United States)

    Castellini, Claudio; Artemiadis, Panagiotis; Wininger, Michael; Ajoudani, Arash; Alimusaj, Merkur; Bicchi, Antonio; Caputo, Barbara; Craelius, William; Dosen, Strahinja; Englehart, Kevin; Farina, Dario; Gijsberts, Arjan; Godfrey, Sasha B.; Hargrove, Levi; Ison, Mark; Kuiken, Todd; Marković, Marko; Pilarski, Patrick M.; Rupp, Rüdiger; Scheme, Erik

    2014-01-01

    One of the hottest topics in rehabilitation robotics is that of proper control of prosthetic devices. Despite decades of research, the state of the art is dramatically behind the expectations. To shed light on this issue, in June, 2013 the first international workshop on Present and future of non-invasive peripheral nervous system (PNS)–Machine Interfaces (MI; PMI) was convened, hosted by the International Conference on Rehabilitation Robotics. The keyword PMI has been selected to denote human–machine interfaces targeted at the limb-deficient, mainly upper-limb amputees, dealing with signals gathered from the PNS in a non-invasive way, that is, from the surface of the residuum. The workshop was intended to provide an overview of the state of the art and future perspectives of such interfaces; this paper represents is a collection of opinions expressed by each and every researcher/group involved in it. PMID:25177292

  15. 采用CATIA V5的曲面文字数控雕刻%CNC machining carving processing of surface text based on CATIA V5

    Institute of Scientific and Technical Information of China (English)

    顾丽敏

    2012-01-01

    探讨了采用CATIA V5软件在FANUC四轴数控加工中心上进行曲面刻字的方法,包括曲面文字的CAD建模及CAM雕刻,并将软件生成的刀具轨迹G代码传输至FANUC数控加工中心,实现了曲面文字的雕刻.该方法提高了曲面文字雕刻的精度,同时扩展了数控加工中心的产品加工范围,实现了数控加工中心的“一机多用”.%A four-axis CNC machining carving method in the hemisphere surface parts by CATIA V5 is recommended,including CAD modeling & CAM carving machining in the hemisphere surface. The reasonable CNC program was transmitted to the FANUC CNC machine,and realized the actual engraving processing of the surface. The method both enhanced the quality of the parts also expanded the product range of the CNC machine.

  16. The Effects of Different Electrode Types for Obtaining Surface Machining Shape on Shape Memory Alloy Using Electrochemical Machining

    Science.gov (United States)

    Choi, S. G.; Kim, S. H.; Choi, W. K.; Moon, G. C.; Lee, E. S.

    2017-06-01

    Shape memory alloy (SMA) is important material used for the medicine and aerospace industry due to its characteristics called the shape memory effect, which involves the recovery of deformed alloy to its original state through the application of temperature or stress. Consumers in modern society demand stability in parts. Electrochemical machining is one of the methods for obtained these stabilities in parts requirements. These parts of shape memory alloy require fine patterns in some applications. In order to machine a fine pattern, the electrochemical machining method is suitable. For precision electrochemical machining using different shape electrodes, the current density should be controlled precisely. And electrode shape is required for precise electrochemical machining. It is possible to obtain precise square holes on the SMA if the insulation layer controlled the unnecessary current between electrode and workpiece. If it is adjusting the unnecessary current to obtain the desired shape, it will be a great contribution to the medical industry and the aerospace industry. It is possible to process a desired shape to the shape memory alloy by micro controlling the unnecessary current. In case of the square electrode without insulation layer, it derives inexact square holes due to the unnecessary current. The results using the insulated electrode in only side show precise square holes. The removal rate improved in case of insulated electrode than others because insulation layer concentrate the applied current to the machining zone.

  17. The influence of cooling techniques on cutting forces and surface roughness during cryogenic machining of titanium alloys

    Science.gov (United States)

    Wstawska, Iwona; Ślimak, Krzysztof

    2016-12-01

    Titanium alloys are one of the materials extensively used in the aerospace industry due to its excellent properties of high specific strength and corrosion resistance. On the other hand, they also present problems wherein titanium alloys are extremely difficult materials to machine. In addition, the cost associated with titanium machining is also high due to lower cutting velocities and shorter tool life. The main objective of this work is a comparison of different cooling techniques during cryogenic machining of titanium alloys. The analysis revealed that applied cooling technique has a significant influence on cutting force and surface roughness (Ra parameter) values. Furthermore, in all cases observed a positive influence of cryogenic machining on selected aspects after turning and milling of titanium alloys. This work can be also the starting point to the further research, related to the analysis of cutting forces and surface roughness during cryogenic machining of titanium alloys.

  18. Error Analysis and Its Offset on the NC Lathe Machine in Cutting a Semi-Sphere Surface

    Institute of Scientific and Technical Information of China (English)

    ZHENG Yu-cai; LI Cheng-zhi; LIU Chang-rong; LIU Tao; GUO Xiu-hua

    2007-01-01

    This paper analyzed the errors that occurred by leaving the shape of the cutting edge out of consideration on a NC lathe machine in cutting a semi-sphere surface and brought forward a method to offset these errors and the correct calculated formula for some parameters on the basis of experiments. It has increased the manufacturing accuracy of the semi-sphere surface on the NC lathe machine.

  19. CONTROL OF METAL SURFACES MACHINED IN ACCORDANCE WITH THE DIAMOND NANOMACHINING TECHNOLOGY BASED ON THE ELECTRON WORK FUNCTION

    Directory of Open Access Journals (Sweden)

    G. V. Sharonov

    2015-01-01

    Full Text Available Dimensional machining technology is based on the use of integrated geometric parameters of machined surfaces. Technological impact of a pick results in oxidation processes and changes in physic-chemical parameters of surface. Control of only geometric parameters is insufficient to describe characteristics of machining and formation of ultra-smooth surfaces. The electron work function is therefore used. The aim of the work was to study electrophysical states of optic surfaces of non-ferrous metals and alloys in relation to geometric and physic-chemical parameters according to the distribution of the electron work function over the surface. We conducted the study on experimental metal samples made of copper and aluminum alloy, machined in accordance with the diamond nanomachining technology. The diamond nanomachining technology would be capable of ensuring the roughness of non-ferrous metals and alloys machined at the level of Ra ≤ 0,005 µm. Modernized Kelvin probe was used as the registration technique of the changes of the electron work function over the surface. Dependence between the electron work function value, as well as its alteration and the physicchemical and geometric parameters of a surface has been determined. It has been shown that the diamond nanomachining technology makes it possible to obtain electro-physically uniform optical surfaces on copper and aluminum alloy with the minimal range of the distribution of the electric potential over the surface

  20. Raw milk from vending machines: Effects of boiling, microwave treatment, and refrigeration on microbiological quality.

    Science.gov (United States)

    Tremonte, Patrizio; Tipaldi, Luca; Succi, Mariantonietta; Pannella, Gianfranco; Falasca, Luisa; Capilongo, Valeria; Coppola, Raffaele; Sorrentino, Elena

    2014-01-01

    In Italy, the sale of raw milk from vending machines has been allowed since 2004. Boiling treatment before its use is mandatory for the consumer, because the raw milk could be an important source of foodborne pathogens. This study fits into this context with the aim to evaluate the microbiological quality of 30 raw milk samples periodically collected (March 2013 to July 2013) from 3 vending machines located in Molise, a region of southern Italy. Milk samples were stored for 72 h at 4 °C and then subjected to different treatments, such as boiling and microwaving, to simulate domestic handling. The results show that all the raw milk samples examined immediately after their collection were affected by high microbial loads, with values very close to or even greater than those acceptable by Italian law. The microbial populations increased during refrigeration, reaching after 72 h values of about 8.0 log cfu/mL for Pseudomonas spp., 6.5 log cfu/mL for yeasts, and up to 4.0 log cfu/mL for Enterobacteriaceae. Boiling treatment, applied after 72 h to refrigerated milk samples, caused complete decontamination, but negatively affected the nutritional quality of the milk, as demonstrated by a drastic reduction of whey proteins. The microwave treatment at 900 W for 75 s produced microbiological decontamination similar to that of boiling, preserving the content in whey proteins of milk. The microbiological characteristics of raw milk observed in this study fully justify the obligation to boil the raw milk from vending machines before consumption. However, this study also showed that domestic boiling causes a drastic reduction in the nutritional value of milk. Microwave treatment could represent a good alternative to boiling, on the condition that the process variables are standardized for safe domestic application. Copyright © 2014 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  1. Control of deviations and prediction of surface roughness from micro machining of THz waveguides using acoustic emission signals

    Science.gov (United States)

    Griffin, James M.; Diaz, Fernanda; Geerling, Edgar; Clasing, Matias; Ponce, Vicente; Taylor, Chris; Turner, Sam; Michael, Ernest A.; Patricio Mena, F.; Bronfman, Leonardo

    2017-02-01

    By using acoustic emission (AE) it is possible to control deviations and surface quality during micro milling operations. The method of micro milling is used to manufacture a submillimetre waveguide where micro machining is employed to achieve the required superior finish and geometrical tolerances. Submillimetre waveguide technology is used in deep space signal retrieval where highest detection efficiencies are needed and therefore every possible signal loss in the receiver has to be avoided and stringent tolerances achieved. With a sub-standard surface finish the signals travelling along the waveguides dissipate away faster than with perfect surfaces where the residual roughness becomes comparable with the electromagnetic skin depth. Therefore, the higher the radio frequency the more critical this becomes. The method of time-frequency analysis (STFT) is used to transfer raw AE into more meaningful salient signal features (SF). This information was then correlated against the measured geometrical deviations and, the onset of catastrophic tool wear. Such deviations can be offset from different AE signals (different deviations from subsequent tests) and feedback for a final spring cut ensuring the geometrical accuracies are met. Geometrical differences can impact on the required transfer of AE signals (change in cut off frequencies and diminished SNR at the interface) and therefore errors have to be minimised to within 1 μm. Rules based on both Classification and Regression Trees (CART) and Neural Networks (NN) were used to implement a simulation displaying how such a control regime could be used as a real time controller, be it corrective measures (via spring cuts) over several initial machining passes or, with a micron cut introducing a level plain measure for allowing setup corrective measures (similar to a spirit level).

  2. Prediction of Machine Tool Condition Using Support Vector Machine

    Science.gov (United States)

    Wang, Peigong; Meng, Qingfeng; Zhao, Jian; Li, Junjie; Wang, Xiufeng

    2011-07-01

    Condition monitoring and predicting of CNC machine tools are investigated in this paper. Considering the CNC machine tools are often small numbers of samples, a condition predicting method for CNC machine tools based on support vector machines (SVMs) is proposed, then one-step and multi-step condition prediction models are constructed. The support vector machines prediction models are used to predict the trends of working condition of a certain type of CNC worm wheel and gear grinding machine by applying sequence data of vibration signal, which is collected during machine processing. And the relationship between different eigenvalue in CNC vibration signal and machining quality is discussed. The test result shows that the trend of vibration signal Peak-to-peak value in surface normal direction is most relevant to the trend of surface roughness value. In trends prediction of working condition, support vector machine has higher prediction accuracy both in the short term ('One-step') and long term (multi-step) prediction compared to autoregressive (AR) model and the RBF neural network. Experimental results show that it is feasible to apply support vector machine to CNC machine tool condition prediction.

  3. Surface topography characterization using an atomic force microscope mounted on a coordinate measuring machine

    DEFF Research Database (Denmark)

    De Chiffre, Leonardo; Hansen, H.N; Kofod, N

    1999-01-01

    The paper describes the construction, testing and use of an integrated system for topographic characterization of fine surfaces on parts having relatively big dimensions. An atomic force microscope (AFM) was mounted on a manual three-coordinate measuring machine (CMM) achieving free positioning o...... areas traced in single scans of 40 mu m x 40 mu m. The results show that surface mapping on industrial surfaces is possible using the Least Mean Square alignment provided by the AFM software....... values in the order of 1 nm. The positioning repeatability of the two horizontal axes of the CMM was determined to +/-1 mu m. Sets of four 20 mu m x 20 mu m areas were traced on fiat objects, combining the data into single 40 mu m x 40 mu m areas, and comparing the roughness values to those for the same...

  4. Statistical analysis of surface roughness of machined graphite by means of CNC milling

    Directory of Open Access Journals (Sweden)

    Orquídea Sánchez López

    2016-09-01

    Full Text Available The aim of this research is to analyze the influence of cutting speed, feed rate and cutting depth on the surface finish of grade GSP-70 graphite specimens for use in electrical discharge machining (EDM for material removal by means of Computer Numerical Control (CNC milling with low-speed machining (LSM. A two-level factorial design for each of the three established factors was used for the statistical analysis. The analysis of variance (ANOVA indicates that cutting speed and feed rate are the two most significant factors with regard to the roughness obtained with grade GSP-70 graphite by means of CNC milling. A second order regression analysis was also conducted to estimate the roughness average (Ra in terms of the cutting speed, feed rate and cutting depth. Finally, the comparison between predicted roughness by means of a second order regression model and the roughness obtained by machined specimens considering the combinations of low and high levels of roughness is also presented.

  5. The Use of Response Surface Methodology to Optimize Parameter Adjustments in CNC Machine Tools

    Directory of Open Access Journals (Sweden)

    Shao-Hsien Chen

    2014-01-01

    Full Text Available This paper mainly covers a research intended to improve the circular accuracy of CNC machine tools and the adjustment and analysis of the main controller parameters applied to improve accuracy. In this study, controller analysis software was used to detect the adjustment status of the servo parameters of the feed axis. According to the FANUC parameter manual, the parameter address, frequency, response measurements, and the one-fourth corner acceleration and deceleration measurements of the machine tools were adjusted. The experimental design (DOE was adopted in this study for taking circular measurements and engaging in the planning and selection of important parameter data. The Minitab R15 software was adopted to predict the experimental data analysis, while the seminormal probability map, Plato, and analysis of variance (ANOVA were adopted to determine the impacts of the significant parameter factors and the interactions among them. Additionally, based on the response surface map and contour plot, the optimal values were obtained. In addition, comparison and verification were conducted through the Taguchi method, regression analysis to improved machining accuracy and efficiency. The unadjusted error was 7.8 μm; through the regression analysis method, the error was 5.8 μm and through the Taguchi analysis method, the error was 6.4 μm.

  6. No-reference video quality measurement: added value of machine learning

    Science.gov (United States)

    Mocanu, Decebal Constantin; Pokhrel, Jeevan; Garella, Juan Pablo; Seppänen, Janne; Liotou, Eirini; Narwaria, Manish

    2015-11-01

    Video quality measurement is an important component in the end-to-end video delivery chain. Video quality is, however, subjective, and thus, there will always be interobserver differences in the subjective opinion about the visual quality of the same video. Despite this, most existing works on objective quality measurement typically focus only on predicting a single score and evaluate their prediction accuracies based on how close it is to the mean opinion scores (or similar average based ratings). Clearly, such an approach ignores the underlying diversities in the subjective scoring process and, as a result, does not allow further analysis on how reliable the objective prediction is in terms of subjective variability. Consequently, the aim of this paper is to analyze this issue and present a machine-learning based solution to address it. We demonstrate the utility of our ideas by considering the practical scenario of video broadcast transmissions with focus on digital terrestrial television (DTT) and proposing a no-reference objective video quality estimator for such application. We conducted meaningful verification studies on different video content (including video clips recorded from real DTT broadcast transmissions) in order to verify the performance of the proposed solution.

  7. Study on Surface Engineering of Normalized Steels Subjected To Machine Hardening

    Institute of Scientific and Technical Information of China (English)

    N.Alagurmurthi; K.Palaniradja; V.Soundararajan

    2004-01-01

    Engineering the surfaces of components to improve the life and performance of parts used in automotive and aerospace engineering is the active area of research. Suitable Thermal/Mechanical/Thermo mechanical surface engineerin gtreatments will produce extensive rearrangement of atoms in metals and alloys and corresponding marked variations in Physical, Chemical and Mechanical properties. Among the more important of these treatments are heat treatment processes such as hardening by Quenching, Induction hardening and Case Carburizing which rely on phase transformations to produce desired changes in mechanical properties. Other processes where phase transformation occur are casting, welding and machining etc. [1] Phase transformation may be homogeneous or heterogeneous. Homogeneous involvesrear rangements in the structure of the material taking place simultaneously in all parts of the solid, while the heterogeneous transformation involves structural changes which are more localized. Alternatively they could be called as Isothermal and Nonisothermal transformation. But irrespective of the classification, these transformations alter the structure of the material giving rise to changes in the mechanical and physical properties of the processed material. It is of interest to review some consequences of surface modification in isothermal (Normalizing) and nonisothermal transformations (Machining) of low carbon steels.

  8. Diagnostic measurements on the great machines conditions of lignite surface mines

    Energy Technology Data Exchange (ETDEWEB)

    Helebrant, F.; Jurman, J.; Fries, J. [Technical University of Ostrava, Ostrava-Poruba (Czech Republic)

    2005-07-01

    An analysis of the diagnosis of loading and service dependability of a rail-mounted excavator used in surface lignite mining is described. Wheel power vibrations in electric motor bearings and electric motor input bearings to the gearbox were measured in situ, in horizontal, vertical, and axial directions. The data were analyzed using a mathematical relationship. The results are presented in a loading diagram that shows the deterioration and the acceptable lower bound of machine conditions over time. Work is continuing. 5 refs., 1 fig.

  9. MOUNTABILITY PARTS OF MACHINE WITH ROTATING SURFACE, FITTED WITH POSITIVE CLEARANCE

    Directory of Open Access Journals (Sweden)

    Zbigniew BUDNIAK

    2014-06-01

    Full Text Available In this paper demonstrates the conditions of automatic assembly the parts of machines with rotating surfaces, fitted with positive clearance. Determination of the general condition of asseblability allowed for designation of the acceptable relative displacement and torsion axle, combined parts on the mounting position. The designation of depending allowed for assess the technological capacity of the installation equipment. On the basis of this mathematical model was developed a computer program that allows to determine the effect of geometric, strength and dynamic parameters of the assembly process. The examples of results of numerical calculations are shown in the graphs

  10. Mask synthesis and verification based on geometric model for surface micro-machined MEMS

    Institute of Scientific and Technical Information of China (English)

    LI Jian-hua; LIU Yu-sheng; GAO Shu-ming

    2005-01-01

    Traditional MEMS (microelectromechanical system) design methodology is not a structured method and has become an obstacle for MEMS creative design. In this paper, a novel method of mask synthesis and verification for surface micro-machined MEMS is proposed, which is based on the geometric model of a MEMS device. The emphasis is focused on synthesizing the masks at the basis of the layer model generated from the geometric model of the MEMS device. The method is comprised of several steps: the correction of the layer model, the generation of initial masks and final masks including multi-layer etch masks, and mask simulation. Finally some test results are given.

  11. TECHNOLOGICAL PROVISION OF ACCURACY AND QUALITY PARAMETERS OF INTRICATE PROFILE PARTS AT HIGH-SPEED MULTI-COORDINATE MACHINING

    Directory of Open Access Journals (Sweden)

    V. K. Sheleg

    2009-01-01

    Full Text Available The paper considers requirements to CAM-systems for provision of high-speed multi-coordinate milling, principles of generation and recommendations on trajectory programming for high-speed machining, influence of vibration and balancing of the technological system on parameters of  the machining accuracy, characteristics of a cutting tool, types of tool coatings that is rather actual for improvement of accuracy and quality of intricate profile parts.

  12. Tool selection and collision-free in 5-axis numerical control machining of free-form surfaces

    Institute of Scientific and Technical Information of China (English)

    杨长祺; QIN; Datong; 等

    2002-01-01

    The methodology of 5-axis cutter selection to avert collision for free-form surface machining by flat-end cutters is presented.The combination of different cutters is adopt aiming at short machining time and high precision.The optimal small cutter is determined based on the geometric information of the points where a cutter most probably collide with the machined surface.Several larger cutters are slected to machine the surface in order to find the interference-free area.The difference of machining time for this area between the optimal small cutter and the large cutters is calculated.The functional relationship between the machining time and the radius of a cutter is established,by which the optimal number of cutters is obtained.The combination of cutters,which possesses the minimum overall machining time,is selected as the optimal cutter sizes.A case study has demonstrated the validity of the proposed methodology and algorithms.

  13. Enhancing structural integrity of adhesive bonds through pulsed laser surface micro-machining

    KAUST Repository

    Diaz, Edwin Hernandez

    2015-06-01

    Enhancing the effective peel resistance of plastically deforming adhesive joints through laser-based surface micro-machining Edwin Hernandez Diaz Inspired by adhesion examples commonly found in nature, we reached out to examine the effect of different kinds of heterogeneous surface properties that may replicate this behavior and the mechanisms at work. In order to do this, we used pulsed laser ablation on copper substrates (CuZn40) aiming to increase adhesion for bonding. A Yb-fiber laser was used for surface preparation of the substrates, which were probed with a Scanning Electron Microscope (SEM) and X-ray Photoelectron Spectroscopy (XPS). Heterogeneous surface properties were devised through the use of simplified laser micromachined patterns which may induce sequential events of crack arrest propagation, thereby having a leveraging effect on dissipation. The me- chanical performance of copper/epoxy joints with homogeneous and heterogeneous laser micromachined interfaces was then analyzed using the T-peel test. Fractured surfaces were analyzed using SEM to resolve the mechanism of failure and adhesive penetration within induced surface asperities from the treatment. Results confirm positive modifications of the surface morphology and chemistry from laser ablation that enable mechanical interlocking and cohesive failure within the adhesive layer. Remarkable improvements of apparent peel energy, bond toughness, and effective peel force were appreciated with respect to sanded substrates as control samples.

  14. Surface Free Energy and Dynamic Wettability of Differently Machined Poplar Woods

    Directory of Open Access Journals (Sweden)

    Zhiyong Qin

    2014-04-01

    Full Text Available The surface free energy and dynamic wettability of wood are important to the performance of its adhesive bonding strength. In this work, the surface free energy of poplar wood samples machined with different processes were calculated by the OWRK (geometric mean and vOCG (acid-base methods, and the dynamic wettability of adhesives on wood samples was studied using the S-D wetting model. The results indicate that the contact angles of reference liquids on rotary wood samples were greater than those on planed or sawn wood, and the rotary wood samples were more hydrophobic. The effect of surface roughness on contact angle was insignificant compared with surface structure morphology. The total surface free energy was almost the same for the planed and sawn wood, as calculated by the OWRK and vOCG methods, and the surface free energy of rotary wood samples was lower than that of planed or sawn wood samples. The initial and equilibrium contact angle increased as the viscosity of adhesive increased for all the wood samples, and the contact angles of rotary wood samples were greater than those of planed or sawn wood; however, the K-value was lower. The wettability of the loose side was higher than that of the tight side. Contact angles decreased when surface free energy increased, while the K-value increased.

  15. Application of Response Surface Methodology and Central Composite Inscribed Design for Modeling and Optimization of Marble Surface Quality

    Directory of Open Access Journals (Sweden)

    Sümeyra Cevheroğlu Çıra

    2016-01-01

    Full Text Available Factors affecting the final surface quality of polished marble are not yet fully understood. Clarifying these factors for optimization of multivariate polishing process by trial and error method is difficult, time-consuming, and costly task. In this study, the empirical practices were carried out using an experimental design, specifically, a central composite inscribed (CCI design. The factors considered in CCI design were belt speed, rotational speed, and pressure of the polishing head, and the responses were surface glossiness and roughness. Mathematical models describing responses were produced using experimental datasets, and analysis of variance (ANOVA was used to assess the fit of the models generated with the experimental data. For process optimization, desirability function analysis (DFA was used. This study has shown that the CCI could efficiently be applied for the modelling of polishing machine for surface quality of marble strips. Better surface quality generally resulted from lower belt speeds, which increased contact time between the abrasives and strips. Optimized surface quality for marble specimen was established.

  16. Tool-path planning for free-form surface high-speed high-resolution machining using torus cutter

    Institute of Scientific and Technical Information of China (English)

    WANG Yu-han; LI Ru-qiong; WU Zu-yu; CHEN Zhao-neng

    2006-01-01

    In CNC machining, two essential components decide the accuracy and machining time for a sculptured surface: one is the step-size interval, the other is the tool-path interval. Due to the limitation of the conventional method for calculating the tool-path interval, it cannot satisfy the machining requirement for highspeed and high-resolution machining. Accordingly, for high-speed and high-resolution machining, the current study proposes a new tool-path interval algorithm, plus a variable step-size algorithm for NURBS. Furthermore,a new type cutter, which can improve the cutting efficiency, is investigated in the paper. The transversal equation of the torus cutter onto the flat plan is given in this paper. The tool-path interval is calculated with the transversal equation and the proposed algorithm. The illustrated example shows that the redundant tool paths can be reduced because an accurate tool-path interval could be calculated.

  17. Mathematical modeling and analysis of WEDM machining parameters of nickel-based super alloy using response surface methodology

    Indian Academy of Sciences (India)

    M P GARG; ANISH KUMAR; C K SAHU

    2017-06-01

    Inconel 625 is one of the most versatile nickel-based super alloy used in the aerospace, automobile, chemical processing, oil refining, marine, waste treatment, pulp and paper, and power industries. Wire electrical discharge machining (WEDM) is the process considered in the present text for machining of Inconel 625 as it can provide an effective solution for machining ultra-hard, high-strength and temperature-resistant materials and alloys, overcoming the constraints of the conventional processes. The present work is mainly focused on the analysis and optimization of the WEDM process parameters of Inconel 625. The four machining parameters, that is, pulse on time, pulse off time, spark gap voltage and wire feed have been varied to investigate their effects onthree output responses, such as cutting speed, gap current, and surface roughness. Response surface methodology was used to develop the experimental models. The parametric analysis-based results revealed that pulse on time and pulse off time were significant, spark gap voltage is the least significant, and wire feed as a single factor is insignificant. Multi-objective optimization technique was employed using desirability approach to obtain theoptimal parameters setting. Furthermore, surface topography in terms of machining parameters revealed that pulse on time and pulse off time significantly deteriorate the surface of the machined samples, which produce thedeeper, wider overlapping craters and globules of debris.

  18. Statistical quality control for volumetric modulated arc therapy (VMAT) delivery by using the machine's log data

    Science.gov (United States)

    Cheong, Kwang-Ho; Lee, Me-Yeon; Kang, Sei-Kwon; Yoon, Jai-Woong; Park, Soah; Hwang, Taejin; Kim, Haeyoung; Kim, Kyoung Ju; Han, Tae Jin; Bae, Hoonsik

    2015-07-01

    The aim of this study is to set up statistical quality control for monitoring the volumetric modulated arc therapy (VMAT) delivery error by using the machine's log data. Eclipse and a Clinac iX linac with the RapidArc system (Varian Medical Systems, Palo Alto, USA) are used for delivery of the VMAT plan. During the delivery of the RapidArc fields, the machine determines the delivered monitor units (MUs) and the gantry angle's position accuracy and the standard deviations of the MU ( σMU: dosimetric error) and the gantry angle ( σGA: geometric error) are displayed on the console monitor after completion of the RapidArc delivery. In the present study, first, the log data were analyzed to confirm its validity and usability; then, statistical process control (SPC) was applied to monitor the σMU and the σGA in a timely manner for all RapidArc fields: a total of 195 arc fields for 99 patients. The MU and the GA were determined twice for all fields, that is, first during the patient-specific plan QA and then again during the first treatment. The sMU and the σGA time series were quite stable irrespective of the treatment site; however, the sGA strongly depended on the gantry's rotation speed. The σGA of the RapidArc delivery for stereotactic body radiation therapy (SBRT) was smaller than that for the typical VMAT. Therefore, SPC was applied for SBRT cases and general cases respectively. Moreover, the accuracy of the potential meter of the gantry rotation is important because the σGA can change dramatically due to its condition. By applying SPC to the σMU and σGA, we could monitor the delivery error efficiently. However, the upper and the lower limits of SPC need to be determined carefully with full knowledge of the machine and log data.

  19. Temperature and phase transformations fields during surfacing by welding of CCS machine roll

    Directory of Open Access Journals (Sweden)

    J. Winczek

    2008-08-01

    Full Text Available In work have been presented models of temperature fields and kinetics of phase transformations in continuous casting steel machine roll surfacing spiral welding sequence with swinging motion of welding head. The temperature field was determined by analytical solution for massive body heated by moving voluminal heat source. The progress of diffusional phase transformations was described basing on equation of kinetics JMA-K and Koistinen-Marburger’s for martensitic transfomation. Deliberations were illustrated by computational example of surfaced roll made from steel 13CrMo4. The temperature field and structural components fraction was calcualated in section of regenerated area of material decline (along the roll axis. Considering critical temperatures, heat-affected zones have been determined: A1 and A3 – austenitic transformation, and solidus - fusion line. Accepted technological parameters of rebuilding gave results that reproduce geometry of padding weld heat-affected zones confirmed experimentally.

  20. Shaping of steel mold surface of lens array by electrical discharge machining with spherical ball electrode.

    Science.gov (United States)

    Takino, Hideo; Hosaka, Takahiro

    2016-06-20

    We propose a method for fabricating a spherical lens array mold by electrical discharge machining (EDM) with a ball-type electrode. The electrode is constructed by arranging conductive spherical balls in an array. To fundamentally examine the applicability of the proposed EDM method to the fabrication of lens array molds, we use an electrode having a single ball to shape a lens array mold made of stainless steel with 16 spherical elements, each having a maximum depth of 0.5 mm. As a result, a mold surface is successfully shaped with a peak-to-valley shape accuracy of approximately 10 μm, and an average surface roughness of 0.85 μm.

  1. Effect of High-speed Milling tool path strategies on the surface roughness of Stavax ESR mold insert machining

    Science.gov (United States)

    Mebrahitom, A.; Rizuan, D.; Azmir, M.; Nassif, M.

    2016-02-01

    High speed milling is one of the recent technologies used to produce mould inserts due to the need for high surface finish. It is a faster machining process where it uses a small side step and a small down step combined with very high spindle speed and feed rate. In order to effectively use the HSM capabilities, optimizing the tool path strategies and machining parameters is an important issue. In this paper, six different tool path strategies have been investigated on the surface finish and machining time of a rectangular cavities of ESR Stavax material. CAD/CAM application of CATIA V5 machining module for pocket milling of the cavities was used for process planning.

  2. Quality characteristic association analysis of computer numerical control machine tool based on meta-action assembly unit

    Directory of Open Access Journals (Sweden)

    Yan Ran

    2016-01-01

    Full Text Available As everyone knows, assembly quality plays a very important role in final product quality. Since computer numerical control machine tool is a large system with complicated structure and function, and there are complex association relationships among quality characteristics in assembly process, then it is difficult and inaccurate to analyze the whole computer numerical control machine tool quality characteristic association at one time. In this article, meta-action assembly unit is proposed as the basic analysis unit, of which quality characteristic association is studied to guarantee the whole computer numerical control machine tool assembly quality. First, based on “Function-Motion-Action” decomposition structure, the definitions of meta-action and meta-action assembly unit are introduced. Second, manufacturing process association and meta-action assembly unit quality characteristic association are discussed. Third, after understanding the definitions of information entropy and relative entropy, the concrete meta-action assembly unit quality characteristic association analysis steps based on relative entropy are described in detail. And finally, the lifting piston translation assembly unit of automatic pallet changer is taken as an example, the association degree between internal leakage and the influence factors of part quality characteristics and mate-relationships among them are calculated to figure out the most influential factors, showing the correctness and feasibility of this method.

  3. Machine learning for automatic prediction of the quality of electrophysiological recordings.

    Directory of Open Access Journals (Sweden)

    Thomas Nowotny

    Full Text Available The quality of electrophysiological recordings varies a lot due to technical and biological variability and neuroscientists inevitably have to select "good" recordings for further analyses. This procedure is time-consuming and prone to selection biases. Here, we investigate replacing human decisions by a machine learning approach. We define 16 features, such as spike height and width, select the most informative ones using a wrapper method and train a classifier to reproduce the judgement of one of our expert electrophysiologists. Generalisation performance is then assessed on unseen data, classified by the same or by another expert. We observe that the learning machine can be equally, if not more, consistent in its judgements as individual experts amongst each other. Best performance is achieved for a limited number of informative features; the optimal feature set being different from one data set to another. With 80-90% of correct judgements, the performance of the system is very promising within the data sets of each expert but judgments are less reliable when it is used across sets of recordings from different experts. We conclude that the proposed approach is relevant to the selection of electrophysiological recordings, provided parameters are adjusted to different types of experiments and to individual experimenters.

  4. Statistical quality control for volumetric modulated arc therapy (VMAT) delivery using machine log data

    CERN Document Server

    Cheong, Kwang-Ho; Kang, Sei-Kwon; Yoon, Jai-Woong; Park, Soah; Hwang, Taejin; Kim, Haeyoung; Kim, Kyoung Ju; Han, Tae Jin; Bae, Hoonsik

    2015-01-01

    The aim of this study is to set up statistical quality control for monitoring of volumetric modulated arc therapy (VMAT) delivery error using machine log data. Eclipse and Clinac iX linac with the RapidArc system (Varian Medical Systems, Palo Alto, USA) is used for delivery of the VMAT plan. During the delivery of the RapidArc fields, the machine determines the delivered motor units (MUs) and gantry angle position accuracy and the standard deviations of MU (sigma_MU; dosimetric error) and gantry angle (sigma_GA; geometric error) are displayed on the console monitor after completion of the RapidArc delivery. In the present study, first, the log data was analyzed to confirm its validity and usability; then, statistical process control (SPC) was applied to monitor the sigma_MU and sigma_GA in a timely manner for all RapidArc fields: a total of 195 arc fields for 99 patients. The sigma_MU and sigma_GA were determined twice for all fields, that is, first during the patient-specific plan QA and then again during th...

  5. Evaluation of vehicle interior sound quality using a continuous restricted Boltzmann machine-based DBN

    Science.gov (United States)

    Huang, Hai B.; Li, Ren X.; Yang, Ming L.; Lim, Teik C.; Ding, Wei P.

    2017-02-01

    The perception of vehicle interior sound quality is important for passengers. In this paper, a feature fusion process for extracting the characteristics of vehicle interior noise is studied, and an improved deep belief network (DBN) that uses continuous restricted Boltzmann machines (CRBMs) to model continuous data is proposed. Six types of vehicles are used for recording interior noise under different working conditions, and a corresponding subjective evaluation is implemented. Psychoacoustic metrics and energy-based criteria using the wavelet transform (WT), wavelet packet transform (WPT), empirical mode decomposition (EMD), critical-band-based pass filter, and Mel-scale-based triangular filer approaches have been applied to extract interior noise features and then develop a fusing feature set combining psychoacoustic metrics and critical band energy based on comparisons. Using the obtained fusion feature set, a CRBM-based DBN (CRBM-DBN) model is developed through experiments. The newly developed model is verified by comparing its performance relative to multiple linear regression (MLR), backpropagation neural network (BPNN), and support vector machine (SVM) models. The results show that the proposed CRBM-DBN model has a lower prediction error and higher correlation coefficient with human perception compared to the other considered methods. In addition, CRBM-DBN outperforms BPNN and SVM in terms of stability and reliability. The presented approach may be regarded as a promising method for evaluating vehicle noise.

  6. A mathematical model for surface roughness of fluidic channels produced by grinding aided electrochemical discharge machining (G-ECDM

    Directory of Open Access Journals (Sweden)

    Ladeesh V. G.

    2017-01-01

    Full Text Available Grinding aided electrochemical discharge machining is a hybrid technique, which combines the grinding action of an abrasive tool and thermal effects of electrochemical discharges to remove material from the workpiece for producing complex contours. The present study focuses on developing fluidic channels on borosilicate glass using G-ECDM and attempts to develop a mathematical model for surface roughness of the machined channel. Preliminary experiments are conducted to study the effect of machining parameters on surface roughness. Voltage, duty factor, frequency and tool feed rate are identified as the significant factors for controlling surface roughness of the channels produced by G-ECDM. A mathematical model was developed for surface roughness by considering the grinding action and thermal effects of electrochemical discharges in material removal. Experiments are conducted to validate the model and the results obtained are in good agreement with that predicted by the model.

  7. A mathematical model for surface roughness of fluidic channels produced by grinding aided electrochemical discharge machining (G-ECDM)

    OpenAIRE

    Ladeesh V. G.; Manu R

    2017-01-01

    Grinding aided electrochemical discharge machining is a hybrid technique, which combines the grinding action of an abrasive tool and thermal effects of electrochemical discharges to remove material from the workpiece for producing complex contours. The present study focuses on developing fluidic channels on borosilicate glass using G-ECDM and attempts to develop a mathematical model for surface roughness of the machined channel. Preliminary experiments are conducted to study the effect of mac...

  8. One-step process for superhydrophobic metallic surfaces by wire electrical discharge machining.

    Science.gov (United States)

    Bae, Won Gyu; Song, Ki Young; Rahmawan, Yudi; Chu, Chong Nam; Kim, Dookon; Chung, Do Kwan; Suh, Kahp Y

    2012-07-25

    We present a direct one-step method to fabricate dual-scale superhydrophobic metallic surfaces using wire electrical discharge machining (WEDM). A dual-scale structure was spontaneously formed by the nature of exfoliation characteristic of Al 7075 alloy surface during WEDM process. A primary microscale sinusoidal pattern was formed via a programmed WEDM process, with the wavelength in the range of 200 to 500 μm. Notably, a secondary roughness in the form of microcraters (average roughness, Ra: 4.16 to 0.41 μm) was generated during the exfoliation process without additional chemical treatment. The low surface energy of Al 7075 alloy (γ = 30.65 mJ/m(2)) together with the presence of dual-scale structures appears to contribute to the observed superhydrophobicity with a static contact angle of 156° and a hysteresis less than 3°. To explain the wetting characteristics on dual-scale structures, we used a simple theoretical model. It was found that Cassie state is likely to present on the secondary roughness in all fabricated surfaces. On the other hand, either Wenzel or Cassie state can present on the primary roughness depending on the characteristic length of sinusoidal pattern. In an optimal condition of the serial cutting steps with applied powers of ∼30 and ∼8 kW, respectively, a stable, superhydrophobic metallic surface was created with a sinusoidal pattern of 500 μm wavelength.

  9. Wear Characterization of Cemented Carbides (WC–CoNi Processed by Laser Surface Texturing under Abrasive Machining Conditions

    Directory of Open Access Journals (Sweden)

    Shiqi Fang

    2017-06-01

    Full Text Available Cemented carbides are outstanding engineering materials widely used in quite demanding material removal applications. In this study, laser surface texturing is implemented for enhancing, at the surface level, the intrinsic bulk-like tribological performance of these materials. In this regard, hexagonal pyramids patterned on the cutting surface of a tungsten cemented carbide grade (WC–CoNi have been successfully introduced by means of laser surface texturing. It simulates the surface topography of conventional honing stones for abrasive application. The laser-produced structure has been tested under abrasive machining conditions with full lubrication. Wear of the structure has been characterized and compared, before and after the abrasive machining test, in terms of changes in geometry aspect and surface integrity. It is found that surface roughness of the machined workpiece was improved by the laser-produced structure. Wear characterization shows that laser treatment did not induce any significant damage to the cemented carbide. During the abrasive machining test, the structure exhibited a high wear resistance. Damage features were only discerned at the contacting surface, whereas geometrical shape of pyramids remained unchanged.

  10. Classification of power quality combined disturbances based on phase space reconstruction and support vector machines

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Power Quality (PQ) combined disturbances become common along with ubiquity of voltage flickers and harmonics. This paper presents a novel approach to classify the different patterns of PQ combined disturbances. The classification system consists of two parts, namely the feature extraction and the automatic recognition. In the feature extraction stage, Phase Space Reconstruction (PSR), a time series analysis tool, is utilized to construct disturbance signal trajectories. For these trajectories, several indices are proposed to form the feature vectors. Support Vector Machines (SVMs) are then implemented to recognize the different patterns and to evaluate the efficiencies. The types of disturbances discussed include a combination of short-term disturbances (voltage sags, swells) and long-term disturbances (flickers, harmonics), as well as their homologous single ones. The feasibilities of the proposed approach are verified by simulation with thousands of PQ events. Comparison studies based on Wavelet Transform (WT) and Artificial Neural Network (ANN) are also reported to show its advantages.

  11. Qualitative: Open Source Python Tool for Quality Estimation over Multiple Machine Translation Outputs

    Directory of Open Access Journals (Sweden)

    Eleftherios Avramidis

    2014-09-01

    Full Text Available “Qualitative” is a python toolkit for ranking and selection of sentence-level output by different MT systems using Quality Estimation. The toolkit implements a basic pipeline for annotating the given sentences with black-box features. Consequently, it applies a machine learning mechanism in order to rank data based on models pre-trained on human preferences. The preprocessing pipeline includes support for language models, PCFG parsing, language checking tools and various other pre-processors and feature generators. The code follows the principles of object-oriented programming to allow modularity and extensibility. The tool can operate by processing both batch-files and single sentences. An XML-RPC interface is provided for hooking up with web-services and a graphical animated web-based interface demonstrates its potential on-line use.

  12. Review of data mining applications for quality assessment in manufacturing industry: support vector machines

    Directory of Open Access Journals (Sweden)

    Rostami Hamidey

    2015-01-01

    Full Text Available In many modern manufacturing industries, data that characterize the manufacturing process are electronically collected and stored in databases. Due to advances in data collection systems and analysis tools, data mining (DM has widely been applied for quality assessment (QA in manufacturing industries. In DM, the choice of technique to be used in analyzing a dataset and assessing the quality depend on the understanding of the analyst. On the other hand, with the advent of improved and efficient prediction techniques, there is a need for an analyst to know which tool performs better for a particular type of dataset. Although a few review papers have recently been published to discuss DM applications in manufacturing for QA, this paper provides an extensive review to investigate the application of a special DM technique, namely support vector machine (SVM to deal with QA problems. This review provides a comprehensive analysis of the literature from various points of view as DM concepts, data preprocessing, DM applications for each quality task, SVM preliminaries, and application results. Summary tables and figures are also provided besides to the analyses. Finally, conclusions and future research directions are provided.

  13. Water quality of Danube Delta systems: ecological status and prediction using machine-learning algorithms.

    Science.gov (United States)

    Stoica, C; Camejo, J; Banciu, A; Nita-Lazar, M; Paun, I; Cristofor, S; Pacheco, O R; Guevara, M

    2016-01-01

    Environmental issues have a worldwide impact on water bodies, including the Danube Delta, the largest European wetland. The Water Framework Directive (2000/60/EC) implementation operates toward solving environmental issues from European and national level. As a consequence, the water quality and the biocenosis structure was altered, especially the composition of the macro invertebrate community which is closely related to habitat and substrate heterogeneity. This study aims to assess the ecological status of Southern Branch of the Danube Delta, Saint Gheorghe, using benthic fauna and a computational method as an alternative for monitoring the water quality in real time. The analysis of spatial and temporal variability of unicriterial and multicriterial indices were used to assess the current status of aquatic systems. In addition, chemical status was characterized. Coliform bacteria and several chemical parameters were used to feed machine-learning (ML) algorithms to simulate a real-time classification method. Overall, the assessment of the water bodies indicated a moderate ecological status based on the biological quality elements or a good ecological status based on chemical and ML algorithms criteria.

  14. Application of biomonitoring and support vector machine in water quality assessment

    Institute of Scientific and Technical Information of China (English)

    Yue LIAO; Jian-yu XU; Zhu-wei WANG

    2012-01-01

    The behavior of schools of zebraflsh (Danio rerio) was studied in acute toxicity environments.Behavioral features were extracted and a method for water quality assessment using support vector machine (SVM) was developed.The behavioral parameters of fish were recorded and analyzed during one hour in an environment of a 24-h half-lethal concentration (LC50) of a pollutant.The data were used to develop a method to evaluate water quality,so as to give an early indication of toxicity.Four kinds of metal ions (Cu2+,Hg2+,Cr6+,and Cd2+) were used for toxicity testing.To enhance the efficiency and accuracy of assessment,a method combining SVM and a genetic algorithm (GA) was used.The results showed that the average prediction accuracy of the method was over 80% and the time cost was acceptable.The method gave satisfactory results for a variety of metal pollutants,demonstrating that this is an effective approach to the classification of water quality.

  15. Identical Quality Assurance for Volumetric Modulated Arc Therapy in Elekta and Varian Machines.

    Science.gov (United States)

    Wang, Jiazhou; Hu, Weigang; Peng, Jiayuan; Lu, Saiquan; Zhao, Jun; Xiao, Ying; Zhang, Zhen

    2015-08-01

    Volumetric modulated arc therapy (VMAT) has been adopted by many clinics for its higher delivery efficiency compared to conventional intensity modulated radiotherapy techniques. Currently, the quality assurance (QA) has remained a challenge in that no identical tests are available for accelerators from different vendors. This study is the first attempt to design identical QA tests for the VMAT technique for Varian and Elekta machines. Identical procedures testing MLC positions and movements, dose rate variations, and gantry positions and movement were created for both machines. These included picket fence (PF), dose rate vs. gantry speed (DRGS) and MLC speed vs. dose rate (MLCDR) tests. Deliverable plans for these tests were made with in-house software that was deliverable for linacs from two vendors (Elekta Synergy and Varian Trilogy). The electronic portal imaging device (EPID) was used for these tests. An automated analysis method was established and software was created to quantitatively evaluate the result. The systematic gap position and width errors from PF tests were within 0.5 mm. We evaluated the detectability of this program for introduced errors down to 0.2 mm. Linear relationships existed between the introduced errors and measured errors. In the DRGS test, 99.8% and 100.0% of the intensity deviations from expected profiles were less than 3% for the Synergy and Trilogy, respectively. For the MLCDR, the intensity deviations from expected profiles less than 3% were 100.0% for Synergy and 98.1% for Trilogy. Identical test series were created and implemented for VMAT accelerators from two vendors. Test results were reported from both accelerators. Comparable results were obtained from both vendors, enabling uniform criteria to be established for VMAT quality assurance.

  16. Optimization of the WEDM Parameters on Machining Incoloy800 Super alloy with Multiple Quality Characteristics

    Directory of Open Access Journals (Sweden)

    Muthu Kumar V

    2010-06-01

    Full Text Available The present work demonstrates optimization of Wire Electrical Discharge Machining process parameters of Incoloy800 super alloy with multiple performance characteristics such as Material Removal Rate (MRR, surface roughness and Kerf based on the Grey–Taguchi Method. The process parameters considered in this research work are Gap Voltage, Pulse On-time, Pulse Off-time and Wire Feed. Taguchi’s L9 Orthogonal Array was used to conduct experiments. Optimal levels of process parameters were identified using Grey Relational Analysis and the relatively significant parameters were determined by Analysis of Variance. The variation of output responses with process parameters were mathematically modelled by using non-linear regression analysismethod and the models were checked for their adequacy. Result of confirmation experiments shows that the established mathematical models can predict the output responses with reasonable accuracy.

  17. 76 FR 54800 - International Business Machines (IBM), Software Group Business Unit, Quality Assurance Group, San...

    Science.gov (United States)

    2011-09-02

    ... Employment and Training Administration International Business Machines (IBM), Software Group Business Unit... Application for Reconsideration for the workers and former workers of International Business Machines (IBM), Software Group Business Unit, Optim Data Studio Tools QA, San Jose, California (subject firm)....

  18. Comparison of peri-implant bone formation around injection-molded and machined surface zirconia implants in rabbit tibiae.

    Science.gov (United States)

    Kim, Hong-Kyun; Woo, Kyung Mi; Shon, Won-Jun; Ahn, Jin-Soo; Cha, Seunghee; Park, Young-Seok

    2015-01-01

    The aim of this study was to compare osseointegration and surface characteristics of zirconia implants made by the powder injection molding (PIM) technique against those made by the conventional milling procedure in rabbit tibiae. Surface characteristics of 2 types of implants were evaluated. Sixteen rabbits received 2 types of external hex implants with similar geometry, either machined zirconia implants or PIM zirconia implants, in the tibiae. Removal torque tests and histomorphometric analyses were performed. The roughness of the PIM zirconia implants was higher than that of machined zirconia implants. The PIM zirconia implants exhibited significantly higher bone-implant contact and removal torque values than the machined zirconia implants (pmold etching technique, can produce substantially rougher surfaces on zirconia implants.

  19. Ultrasonic image restoration based on support vector machine for surfacing interface testing

    Institute of Scientific and Technical Information of China (English)

    Gao Shuangsheng; Gang Tie; Chi Dazhao

    2007-01-01

    In order to restore the degraded ultrasonic C-scan image for testing surfacing interface, a method based on support vector regression (SVR) network is proposed. By using the image of a simulating defect, the network is trained and a mapping relationship between the degraded and restored image is founded. The degraded C-scan image of Cu-Steel surfacing interface is processed by the trained network and improved image is obtained. The result shows that the method can effectively suppress the noise and deblur the defect edge in the image, and provide technique support for quality and reliability evaluation of the surfacing weld.

  20. Precision Measurement of Cylinder Surface Profile on an Ultra-Precision Machine Tool

    Science.gov (United States)

    Lee, J. C.; Noh, Y. J.; Arai, Y.; Gao, W.; Park, C. H.

    2009-01-01

    This paper describes the measurement of the surface straightness profile of a cylinder workpiece on an ultra-precision machine tool which has a T-base design with a spindle, an X-slide and a Z-slide. The movement range of the X-slide is 220 mm and that of the Z-slide is 150 mm, which have roller bearings in common. Two capacitive sensors are employed to scan a cylinder workpiece mounted on the spindle along the Z-axis. The straightness error motion of the Z-slide is measured to be approximately 100 nm by the reversal method. The straightness profile of the cylinder workpiece is evaluated to be approximately 400 nm by separation of the motion error, simultaneously.

  1. Surface topography of machined fibre reinforced plastics obtained by stylus instruments and optical profilometers

    DEFF Research Database (Denmark)

    Eriksen, Else; Hansen, Hans Nørgaard

    1998-01-01

    introduced. They use another working principle to obtain the same parameters, but the settings of most of the measuring variables are not standardized. The present study has investigated aspects that have to be taken into account when the roughness of short fibre reinforced thermoplastics is measured...... identical values, whereas significantly higher roughnesses were measured with one of the two optical instruments. The optical instruments were identical but with different settings of the control parameters, which resulted in large deviations between the values measured. Some of the differences between...... by stylus instruments and by optical profilometers. The measurements were performed on machined surfaces with three distinct different roughness levels. The materials were two thermoplastics, polyoxymethylene and polypropylene, reinforced with short glass fibres. The two stylus instruments gave almost...

  2. Machining of the Flat Surfaces with Abrasive-metallic Lapping Tools

    Institute of Scientific and Technical Information of China (English)

    Adam Barylski

    2004-01-01

    The constructional principle of abrasion metal disc is that abrasive insertions are spread uniformly on the working surface of a metal base. During lapping by means of such tools only the machining fluid is dosed and that by drop.Abrasive elements of circular shape pellets are produced by mixing boron carbide BC400 micrograins with electrographite components, the pellets were pressed with a load of about 12 kN. Next they were heated in furnace at about 520K for hours,then cooled together with the furnace. Tests were carried out on the making of circular abrasive insertions of which the main components were born carbide and micrograins of electric copper mixed the epoxide resins.

  3. Machining of the Flat Surfaces with Abrasive-metallic Lapping Tools

    Institute of Scientific and Technical Information of China (English)

    AdamBarylski

    2004-01-01

    The constructional principle of abrasion metal disc is that abrasive insertions are spread uniformly on the working surface of a metal base. During lapping by means of such tools only the machining fluid is dosed and that by drop. Abrasive elements of circular shape pellets are produced by mixing boron carbide BC400 micrograins with electrographite components, the pellets were pressed with a load of about 12 kN. Next they were heated in furnace at about 520K for hours, then cooled together with the furnace. Tests were carried out on the making of circular abrasive insertions of which the main components were born carbide and micrograins of electric copper mixed the epoxide resins.

  4. Finger milling-cutter CNC generating hypoid pinion tooth surfaces based on modified-roll method and machining simulation

    Science.gov (United States)

    Li, Genggeng; Deng, Xiaozhong; Wei, Bingyang; Lei, Baozhen

    2011-05-01

    The two coordinate systems of cradle-type hypoid generator and free-form CNC machine tool by application disc milling-cutter to generate hypoid pinion tooth surfaces based on the modified-roll method were set up, respectively, and transformation principle and method for machine-tool settings between the two coordinate systems was studied. It was presented that finger milling-cutter was mounted on imagined disc milling-cutter and its motion was controlled directly by CNC shafts to replace disc milling-cutter blades effective cutting motion. Finger milling-cutter generation accomplished by ordered circular interpolation was determined, and interpolation center, starting and ending were worked out. Finally, a hypoid pinion was virtually machined by using CNC machining simulation software VERICUT.

  5. Study on Surface Integrity of AISI 1045 Carbon Steel when machined by Carbide Cutting Tool under wet conditions

    Directory of Open Access Journals (Sweden)

    Tamin N. Fauzi

    2017-01-01

    Full Text Available This paper presents the evaluation of surface roughness and roughness profiles when machining carbon steel under wet conditions with low and high cutting speeds. The workpiece materials and cutting tools selected in this research were AISI 1045 carbon steel and canela carbide inserts graded PM25, respectively. The cutting tools undergo machining tests by CNC turning operations and their performances were evaluated by their surface roughness value and observation of the surface roughness profile. The machining tests were held at varied cutting speeds of 35 to 53 m/min, feed rate of 0.15 to 0.50 mm/rev and a constant depth of cut of 1 mm. From the analysis, it was found that surface roughness increased as the feed rate increased. Varian of surface roughness was suspected due to interaction between cutting speeds and feed rates as well as nose radius conditions; whether from tool wear or the formation of a built-up edge. This study helps us understand the effect of cutting speed and feed rate on surface integrity, when machining AISI 1045 carbon steel using carbide cutting tools, under wet cutting conditions.

  6. Influence of Surface Carburization of Machinable Ceramics on Its Pulsed Flashover Characteristics in Vacuum%Influence of Surface Carburization of Machinable Ceramics on Its Pulsed Flashover Characteristics in Vacuum

    Institute of Scientific and Technical Information of China (English)

    郑楠; 黄学增; 穆海宝; 张冠军

    2011-01-01

    For pulsed power devices, surface flashover phenomena across solid insulators greatly restrict their overall performance. In recent decades, much attention has been paid on enhancing the surface electric withstanding strength of insulators, and it is found that surface treatment of material is useful to improve the surface flashover voltage. The carburization treatment is employed to modify the surface components of newly-developed machinable ceramics (MC) materials. A series of MC samples with different glucose solution concentration (0%, 10%, 20%, 30% and 40%) are prepared by chemical reactions for surface carburization modification, and their surface fiashover characteristics are investigated under pulsed voltage in vacuum. It is found that the surface carburization treatment greatly modifies the surface resistivity of MCs and hence the flashover behaviors. Based on the reduction of surface resistivity and the secondary electron emission avalanche (SEEA) theory, the adjustment of flashover withstanding ability can be reasonably explained.

  7. Surface water quality assessment by environmetric methods.

    Science.gov (United States)

    Boyacioglu, Hülya; Boyacioglu, Hayal

    2007-08-01

    This environmetric study deals with the interpretation of river water monitoring data from the basin of the Buyuk Menderes River and its tributaries in Turkey. Eleven variables were measured to estimate water quality at 17 sampling sites. Factor analysis was applied to explain the correlations between the observations in terms of underlying factors. Results revealed that, water quality was strongly affected from agricultural uses. Cluster analysis was used to classify stations with similar properties and results distinguished three groups of stations. Water quality at downstream of the river was quite different from the other part. It is recommended to involve the environmetric data treatment as a substantial procedure in assessment of water quality data.

  8. Advanced Electrochemical Machining (ECM) for tungsten surface micro-structuring in blanket applications

    Energy Technology Data Exchange (ETDEWEB)

    Holstein, Nils, E-mail: nils.holstein@kit.edu [Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, D-76344 Eggenstein-Leopoldshafen, Baden-Württemberg (Germany); Krauss, Wolfgang; Konys, Jürgen [Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, D-76344 Eggenstein-Leopoldshafen, Baden-Württemberg (Germany); Heuer, Simon; Weber, Thomas [Research Center Jülich, Institute of Energy- and Climate Research – Plasma Physics (IEK-4), D-52425 Jülich (Germany)

    2016-11-01

    Highlights: • Electrochemical Machining is an appropriate tool for tungsten shaping. • Progress in shaping achieved by combination of ECM with advanced micro-lithography. • Application in First Wall for connection of plasma facing material to breeder blanket. • Successful development of adhesion promotors by ECM for plasma spraying interlayers. • Microstructure electrochemical manufacturing of tungsten in sizes of 100 μm achieved. - Abstract: Plasma facing components for fusion applications must have to exhibit long-term stability under extreme physical conditions, and therefore any material imperfections caused by mechanical and/or thermal stresses in the shaping processes cannot be tolerated due to a high risk of possible technical failures under fusion conditions. To avoid such defects, the method of Electrochemical Machining (ECM) enables a complete defect-free processing of removal of tungsten material during the desired shaping, also for high penetration depths. Furthermore, supported by lithographic mask pretreatment, three-dimensional distinct geometric structures can be positive-imaged via the directional galvanic dissolution applying M-ECM process into the tungsten bulk material. New required applications for tungsten components, e.g. as adhesion promotors in W-surfaces to enable sure grip and bonding of thick plasma-spraying layers for blanket components, will define the way of further miniaturization of well-established millimeter dimensioned M-ECM shaping processes to dimensions of 100 μm and furthermore down to 50 μm. Besides current M-ECM limits the article describes inevitable needs of further developments for mask resists, mask materials and the resulting ECM parameters, to reach the needed accuracy in tungsten microstructure. The achieved progress and observed correlations of processing parameters will be manifested by produced demonstrators made by the new “μM”-ECM process.

  9. Downscaling of Aircraft-, Landsat-, and MODIS-based Land Surface Temperature Images with Support Vector Machines

    Science.gov (United States)

    Ha, W.; Gowda, P. H.; Oommen, T.; Howell, T. A.; Hernandez, J. E.

    2010-12-01

    High spatial resolution Land Surface Temperature (LST) images are required to estimate evapotranspiration (ET) at a field scale for irrigation scheduling purposes. Satellite sensors such as Landsat 5 Thematic Mapper (TM) and Moderate Resolution Imaging Spectroradiometer (MODIS) can offer images at several spectral bandwidths including visible, near-infrared (NIR), shortwave-infrared, and thermal-infrared (TIR). The TIR images usually have coarser spatial resolutions than those from non-thermal infrared bands. Due to this technical constraint of the satellite sensors on these platforms, image downscaling has been proposed in the field of ET remote sensing. This paper explores the potential of the Support Vector Machines (SVM) to perform downscaling of LST images derived from aircraft (4 m spatial resolution), TM (120 m), and MODIS (1000 m) using normalized difference vegetation index images derived from simultaneously acquired high resolution visible and NIR data (1 m for aircraft, 30 m for TM, and 250 m for MODIS). The SVM is a new generation machine learning algorithm that has found a wide application in the field of pattern recognition and time series analysis. The SVM would be ideally suited for downscaling problems due to its generalization ability in capturing non-linear regression relationship between the predictand and the multiple predictors. Remote sensing data acquired over the Texas High Plains during the 2008 summer growing season will be used in this study. Accuracy assessment of the downscaled 1, 30, and 250 m LST images will be made by comparing them with LST data measured with infrared thermometers at a small spatial scale, upscaled 30 m aircraft-based LST images, and upscaled 250 m TM-based LST images, respectively.

  10. A noninvasive technique for real-time detection of bruises in apple surface based on machine vision

    Science.gov (United States)

    Zhao, Juan; Peng, Yankun; Dhakal, Sagar; Zhang, Leilei; Sasao, Akira

    2013-05-01

    Apple is one of the highly consumed fruit item in daily life. However, due to its high damage potential and massive influence on taste and export, the quality of apple has to be detected before it reaches the consumer's hand. This study was aimed to develop a hardware and software unit for real-time detection of apple bruises based on machine vision technology. The hardware unit consisted of a light shield installed two monochrome cameras at different angles, LED light source to illuminate the sample, and sensors at the entrance of box to signal the positioning of sample. Graphical Users Interface (GUI) was developed in VS2010 platform to control the overall hardware and display the image processing result. The hardware-software system was developed to acquire the images of 3 samples from each camera and display the image processing result in real time basis. An image processing algorithm was developed in Opencv and C++ platform. The software is able to control the hardware system to classify the apple into two grades based on presence/absence of surface bruises with the size of 5mm. The experimental result is promising and the system with further modification can be applicable for industrial production in near future.

  11. Surface texturing of Si3N4–SiC ceramic tool components by pulsed laser machining

    CSIR Research Space (South Africa)

    Tshabalala, LC

    2016-03-01

    Full Text Available Traditional abrasive techniques such as grinding and lapping have long been used in the surface conditioning of engineering materials. However, in the processing of hard and brittle materials like silicon nitride (Si(sub3)N(sub4)), machining...

  12. INVESTIGATION OF SURFACE PROPERTIES IN MANGANESE POWDER MIXED ELECTRICAL DISCHARGE MACHINING OF OHNS AND D2 DIE STEELS

    Directory of Open Access Journals (Sweden)

    S. Kumar

    2010-12-01

    Full Text Available The electrical discharge machining (EDM process is used for generating accurate internal profiles in hardened materials. An powder additive in the hydrocarbon dielectric affects the energy distribution and sparking efficiency, and consequently the surface finish and micro-hardness. In this paper the Taguchi approach has been used to optimize and compare the surface properties in manganese powder-mixed EDM of oil-hardening non-shrinkable (OHNS and high-carbon high-chromium (D2 die steels. The results of the study show an improvement of 73% and 71.6% in the micro-hardness of OHNS and D2 die steels, respectively. The machining parameters for the best value of micro-hardness are found to be the same for both work materials. A scanning electron microscopy and X-ray diffraction analysis of the machined surfaces show a transfer of manganese and carbon from the plasma channel in the form of manganese carbide. The chemical composition of the machined surface has been further checked on an optical emission spectrometer to verify and quantify the results.

  13. Determination of High-Frequency d- and q-axis Inductances for Surface-Mounted Permanent-Magnet Synchronous Machines

    DEFF Research Database (Denmark)

    Lu, Kaiyuan; Vetuschi, M.; Rasmussen, Peter Omand;

    2010-01-01

    This paper presents a reliable method for the experimental determination of high-frequency d- and q -axis inductances for surface-mounted permanent-magnet synchronous machines (SMPMSMs). Knowledge of the high-frequency d- and q-axis inductances plays an important role in the efficient design...

  14. Infrared machine vision system for the automatic detection of olive fruit quality.

    Science.gov (United States)

    Guzmán, Elena; Baeten, Vincent; Pierna, Juan Antonio Fernández; García-Mesa, José A

    2013-11-15

    External quality is an important factor in the extraction of olive oil and the marketing of olive fruits. The appearance and presence of external damage are factors that influence the quality of the oil extracted and the perception of consumers, determining the level of acceptance prior to purchase in the case of table olives. The aim of this paper is to report on artificial vision techniques developed for the online estimation of olive quality and to assess the effectiveness of these techniques in evaluating quality based on detecting external defects. This method of classifying olives according to the presence of defects is based on an infrared (IR) vision system. Images of defects were acquired using a digital monochrome camera with band-pass filters on near-infrared (NIR). The original images were processed using segmentation algorithms, edge detection and pixel value intensity to classify the whole fruit. The detection of the defect involved a pixel classification procedure based on nonparametric models of the healthy and defective areas of olives. Classification tests were performed on olives to assess the effectiveness of the proposed method. This research showed that the IR vision system is a useful technology for the automatic assessment of olives that has the potential for use in offline inspection and for online sorting for defects and the presence of surface damage, easily distinguishing those that do not meet minimum quality requirements. Crown Copyright © 2013 Published by Elsevier B.V. All rights reserved.

  15. Preliminary study of online machine translation use of nursing literature: quality evaluation and perceived usability

    Directory of Open Access Journals (Sweden)

    Anazawa Ryoko

    2012-11-01

    Full Text Available Abstract Background Japanese nurses are increasingly required to read published international research in clinical, educational, and research settings. Language barriers are a significant obstacle, and online machine translation (MT is a tool that can be used to address this issue. We examined the quality of Google Translate® (English to Japanese and Korean to Japanese, which is a representative online MT, using a previously verified evaluation method. We also examined the perceived usability and current use of online MT among Japanese nurses. Findings Randomly selected nursing abstracts were translated and then evaluated for intelligibility and usability by 28 participants, including assistants and research associates from nursing universities throughout Japan. They answered a questionnaire about their online MT use. From simple comparison of mean scores between two language pairs, translation quality was significantly better, with respect to both intelligibility and usability, for Korean-Japanese than for English-Japanese. Most respondents perceived a language barrier. Online MT had been used by 61% of the respondents and was perceived as not useful enough. Conclusion Nursing articles translated from Korean into Japanese by an online MT system could be read at an acceptable level of comprehension, but the same could not be said for English-Japanese translations. Respondents with experience using online MT used it largely to grasp the overall meanings of the original text. Enrichment in technical terms appeared to be the key to better usability. Users will be better able to use MT outputs if they improve their foreign language proficiency as much as possible. Further research is being conducted with a larger sample size and detailed analysis.

  16. Effect of machining fluid on the process performance of wire electrical discharge machining of nanocomposite ceramic

    Directory of Open Access Journals (Sweden)

    Zhang Chengmao

    2015-01-01

    Full Text Available Wire electric discharge machining (WEDM promise to be effective and economical techniques for the production of tools and parts from conducting ceramic blanks. However, the manufacturing of nanocomposite ceramics blanks with these processes is a long and costly process. This paper presents a new process of machining nanocomposite ceramics using WEDM. WEDM uses water based emulsion, polyvinyl alcohol and distilled water as the machining fluid. Machining fluid is a primary factor that affects the material removal rate and surface quality of WEDM. The effects of emulsion concentration, polyvinyl alcohol concentration and distilled water of the machining fluid on the process performance have been investigated.

  17. A Review of Additive Mixed-Electric Discharge Machining: Current Status and Future Perspectives for Surface Modification of Biomedical Implants

    Directory of Open Access Journals (Sweden)

    Abdul’Azeez Abdu Aliyu

    2017-01-01

    Full Text Available Surface treatment remained a key solution to numerous problems of synthetic hard tissues. The basic methods of implant surface modification include various physical and chemical deposition techniques. However, most of these techniques have several drawbacks such as excessive cost and surface cracks and require very high sintering temperature. Additive mixed-electric discharge machining (AM-EDM is an emerging technology which simultaneously acts as a machining and surface modification technique. Aside from the mere molds, dies, and tool fabrication, AM-EDM is materializing to finishing of automobiles and aerospace, nuclear, and biomedical components, through the concept of material migrations. The mechanism of material transfer by AM-EDM resembles electrophoretic deposition, whereby the additives in the AM-EDM dielectric fluids are melted and migrate to the machined surface, forming a mirror-like finishing characterized by extremely hard, nanostructured, and nanoporous layers. These layers promote the bone in-growth and strengthen the cell adhesion. Implant shaping and surface treatment through AM-EDM are becoming a key research focus in recent years. This paper reports and summarizes the current advancement of AM-EDM as a potential tool for orthopedic and dental implant fabrication. Towards the end of this paper, the current challenges and future research trends are highlighted.

  18. Integrating multisensor satellite data merging and image reconstruction in support of machine learning for better water quality management.

    Science.gov (United States)

    Chang, Ni-Bin; Bai, Kaixu; Chen, Chi-Farn

    2017-10-01

    Monitoring water quality changes in lakes, reservoirs, estuaries, and coastal waters is critical in response to the needs for sustainable development. This study develops a remote sensing-based multiscale modeling system by integrating multi-sensor satellite data merging and image reconstruction algorithms in support of feature extraction with machine learning leading to automate continuous water quality monitoring in environmentally sensitive regions. This new Earth observation platform, termed "cross-mission data merging and image reconstruction with machine learning" (CDMIM), is capable of merging multiple satellite imageries to provide daily water quality monitoring through a series of image processing, enhancement, reconstruction, and data mining/machine learning techniques. Two existing key algorithms, including Spectral Information Adaptation and Synthesis Scheme (SIASS) and SMart Information Reconstruction (SMIR), are highlighted to support feature extraction and content-based mapping. Whereas SIASS can support various data merging efforts to merge images collected from cross-mission satellite sensors, SMIR can overcome data gaps by reconstructing the information of value-missing pixels due to impacts such as cloud obstruction. Practical implementation of CDMIM was assessed by predicting the water quality over seasons in terms of the concentrations of nutrients and chlorophyll-a, as well as water clarity in Lake Nicaragua, providing synergistic efforts to better monitor the aquatic environment and offer insightful lake watershed management strategies. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. INFLUENCE OF FEEDING ELECTRIC ENERGY QUALITY ON HEATING OF THE AUXILIARY MA-CHINES OF AC ELECTRIC ROLLING STOCK

    Directory of Open Access Journals (Sweden)

    O. YU. Baliichuk

    2014-04-01

    Full Text Available Purpose. The article aims to study the problem of increase the reliability of auxiliary machines for AC electric trains during operation in real conditions. Methodology. The peculiarity of system construction of auxiliary machines for AC electric rolling stock is the use of asynchronous motors for general industrial purpose. An engineering method of influence determination on the feeding voltage asymmetry and its deviation from the nominal value on heating of auxiliary machines insulation was proposed. Findings. It is found out that in case when the auxiliary machines of AC electric trains work under asymmetry factor of the voltage 10% or more and feeding voltage deviation from the nominal order 0.6 relative unit then it is possible the overheat of their isolation, even if it has class H. Originality. For the first time the issue of the total insulation heating under such boundary parameters combinations of energy quality, when each of them contributes to the heating insulation increase as compared to the nominal regime of the "rotating phase splitter−auxiliary machinery" system was illuminated. Practical value. Conducted research allow us to establish the boundary parameter values of feeding energy quality (asymmetry factor, feeding voltage deviations from the nominal value, at which additional isolation overheating of this class under the effect of specified factors will not exceed the agreed value.

  20. Characterization of electric discharge machining, subsequent etching and shot-peening as a surface treatment for orthopedic implants

    Science.gov (United States)

    Stráský, Josef; Havlíková, Jana; Bačáková, Lucie; Harcuba, Petr; Mhaede, Mansour; Janeček, Miloš

    2013-09-01

    Presented work aims at multi-method characterization of combined surface treatment of Ti-6Al-4V alloy for biomedical use. Surface treatment consists of consequent use of electric discharge machining (EDM), acid etching and shot peening. Surface layers are analyzed employing scanning electron microscopy and energy dispersive X-ray spectroscopy. Acid etching by strong Kroll's reagent is capable of removing surface layer of transformed material created by EDM. Acid etching also creates partly nanostructured surface and significantly contributes to the enhanced proliferation of the bone cells. The cell growth could be positively affected by the superimposed bone-inspired structure of the surface with the morphological features in macro-, micro- and nano-range. Shot peening significantly improves poor fatigue performance after EDM. Final fatigue performance is comparable to benchmark electropolished material without any adverse surface effect. The proposed three-step surface treatment is a low-cost process capable of producing material that is applicable in orthopedics.

  1. Effects of finishing on the surface quality of precision castings

    Directory of Open Access Journals (Sweden)

    Patejuk A.

    2007-01-01

    Full Text Available The paper presents some manufacturing problems concerning leaded brass casting using the precision casting method. It shows that the quality of the alloy depends on the intermetalic phase compounds known as hard inclusions that are formed in the alloy. The intrusions, composed mainly of iron, have also negative influence on obtaining good quality i.e. smooth surfaces of products. One of the methods to improve surface smoothness proposed by authors is to apply additional copper plating and fine polishing.

  2. Destruction of oral biofilms formed in situ on machined titanium (Ti) surfaces by cold atmospheric plasma.

    Science.gov (United States)

    Idlibi, Ahmad Nour; Al-Marrawi, Fuad; Hannig, Matthias; Lehmann, Antje; Rueppell, Andre; Schindler, Axel; Jentsch, Holger; Rupf, Stefan

    2013-01-01

    The decontamination of implant surfaces represents the basic procedure in the management of peri-implant diseases, but it is still a challenge. The study aimed to evaluate the degradation of oral biofilms grown in situ on machined titanium (Ti) discs by cold atmospheric plasma (CAP). ~200 Ti discs were exposed to the oral cavities of five healthy human volunteers for 72 h. The resulting biofilms were divided randomly between the following treatments: CAP (which varied in mean power, treatment duration, and/or the gas mixture), and untreated and treated controls (diode laser, air-abrasion, chlorhexidine). The viability, quantity, and morphology of the biofilms were determined by live/dead staining, inoculation onto blood agar, quantification of the total protein content, and scanning electron microscopy. Exposure to CAP significantly reduced the viability and quantity of biofilms compared with the positive control treatments. The efficacy of treatment with CAP correlated with the treatment duration and plasma power. No single method achieved complete biofilm removal; however, CAP may provide an effective support to established decontamination techniques for treatment of peri-implant diseases.

  3. Comparative study for surface topography of bone drilling using conventional drilling and loose abrasive machining.

    Science.gov (United States)

    Singh, Gurmeet; Jain, Vivek; Gupta, Dheeraj

    2015-03-01

    Drilling through the bone is a complicated process in orthopaedic surgery. It involves human as a part of the work so it needs better perfection and quality which leads to the sustainability. Different studies were carried out on this curious topic and some interesting results were obtained, which help the orthopaedic surgeon on the operation table. Major problems faced during bone drilling were crack initiation, thermal necrosis and burr formation. The surface topography of the bone is an indirect indication for the sustainability of bone joint. In this study, a comparison is made between conventional and a loose abrasive unconventional drilling technique for the surface characterization of the bone. The attempt has been made to show the feasibility of bone drilling with non-conventional technique and its aftereffect on the bone structure. The burr formation during conventional bone drilling was found to be more which leads to problems such as crack initiation and thermal necrosis. Scanning electrode microscope and surface roughness tester were used to characterize the surface of the fine drilled bone specimen and the results testified quite better surface finish and least crack formation while drilling with loose abrasive unconventional technique.

  4. Positioning method of a cylindrical cutter for ruled surface machining based on minimizing one-sided Hausdorff distance

    Institute of Scientific and Technical Information of China (English)

    Cao Lixin; Dong Lei

    2015-01-01

    Motivated by the definition of the machining errors induced by tool path planning methods, a mapping curve of the tool axis of a cylindrical cutter is constructed on the tool surface. The mapping curve is a typical one that can be used to express the closeness between the tool surface and the surface to be machined. A novel tool path planning method is proposed for flank or plunge milling ruled surfaces based on the minimization of the one-sided Hausdorff distance (HD) from the mapping curve to the surface to be machined. It is a nonlinear optimization problem in best uniform approximation (BUA) or Chebyshev sense. A mathematical programming model for computing the minimum one-sided HD is proposed. The linearization method of the programming model is provided and the final optimal solutions are obtained by simplex method. The effectiveness of the proposed BUA method is verified by two numerical examples and compared with the least squares (LS) and double point offset (DPO) methods. The variation in tool orientation induced by the optimization of the tool positions is also evaluated.

  5. The effect of welding parameters on surface quality of AA6351 aluminium alloy

    Science.gov (United States)

    Yacob, S.; MAli, M. A.; Ahsan, Q.; Ariffin, N.; Ali, R.; Arshad, A.; Wahab, M. I. A.; Ismail, S. A.; Roji, NS M.; Din, W. B. W.; Zakaria, M. H.; Abdullah, A.; Yusof, M. I.; Kamarulzaman, K. Z.; Mahyuddin, A.; Hamzah, M. N.; Roslan, R.

    2015-12-01

    In the present work, the effects of gas metal arc welding-cold metal transfer (GMAW-CMT) parameters on surface roughness are experimentally assessed. The purpose of this study is to develop a better understanding of the effects of welding speed, material thickness and contact tip to work distance on the surface roughness. Experiments are conducted using single pass gas metal arc welding-cold metal transfer (GMAW-CMT) welding technique to join the material. The material used in this experiment was AA6351 aluminum alloy with the thickness of 5mm and 6mm. A Mahr Marsuft XR 20 machine was used to measure the average roughness (Ra) of AA6351 joints. The main and interaction effect analysis was carried out to identify process parameters that affect the surface roughness. The results show that all the input process parameters affect the surface roughness of AA6351 joints. Additionally, the average roughness (Ra) results also show a decreasing trend with increased of welding speed. It is proven that gas metal arc welding-cold metal transfer (GMAW-CMT)welding process has been successful in term of providing weld joint of good surface quality for AA6351 based on the low value surface roughness condition obtained in this setup. The outcome of this experimental shall be valuable for future fabrication process in order to obtained high good quality weld.

  6. Influence of particle size on Cutting Forces and Surface Roughness in Machining of B4Cp - 6061 Aluminium Matrix Composites

    Science.gov (United States)

    Hiremath, Vijaykumar; Badiger, Pradeep; Auradi, V.; Dundur, S. T.; Kori, S. A.

    2016-02-01

    Amongst advanced materials, metal matrix composites (MMC) are gaining importance as materials for structural applications in particular, particulate reinforced aluminium MMCs have received considerable attention due to their superior properties such as high strength to weight ratio, excellent low-temperature performance, high wear resistance, high thermal conductivity. The present study aims at studying and comparing the machinability aspects of B4Cp reinforced 6061Al alloy metal matrix composites reinforced with 37μm and 88μm particulates produced by stir casting method. The micro structural characterization of the prepared composites is done using Scanning Electron Microscopy equipped with EDX analysis (Hitachi Su-1500 model) to identify morphology and distribution of B4C particles in the 6061Al matrix. The specimens are turned on a conventional lathe machine using a Polly crystalline Diamond (PCD) tool to study the effect of particle size on the cutting forces and the surface roughness under varying machinability parameters viz., Cutting speed (29-45 m/min.), Feed rate (0.11-0.33 mm/rev.) and depth of cut (0.5-1mm). Results of micro structural characterization revealed fairly uniform distribution of B4C particles (in both cases i.e., 37μm and 88μm) in 6061Al matrix. The surface roughness of the composite is influenced by cutting speed. The feed rate and depth of cut have a negative influence on surface roughness. The cutting forces decreased with increase in cutting speed whereas cutting forces increased with increase in feed and depth of cut. Higher cutting forces are noticed while machining Al6061 base alloy compared to reinforced composites. Surface finish is high during turning of the 6061Al base alloy and surface roughness is high with 88μm size particle reinforced composites. As the particle size increases Surface roughness also increases.

  7. Engineering of surface microstructure transformations using high rate severe plastic deformation in machining

    Science.gov (United States)

    Abolghasem, Sepideh

    research effort, where Large Strain Machining (LSM) is presented as a controlled test of microstructure response. Sample conditions are created using LSM in Face Centered Cubic (FCC) metals, while characterizing the deformation using Digital Image Correlation(DIC) and Infrared(IR) thermography. Microstructural consequences such as grain size, subgrain size and grain boundary responses resulting from the characterized thermomechanical conditions are examined using Electron Back-Scattered Diffraction (EBSD). Once empirical data is generated across the broad thermomechanical conditions, reliable microstructure maps are populated. This characterization can help understand surface microstructures resulting from shear-based manufacturing processes such as turning, milling, shaping, etc. that are created under analogous thermomechanical conditions. Keywords: microstructure characterization, ultrafine grain microstructure, severe plastic deformation, high speed deformation.

  8. Factors influencing the surface quality of polished tool steels

    Science.gov (United States)

    Rebeggiani, S.; Rosén, B.-G.

    2014-09-01

    Today’s demands on surface quality of moulds for injection moulding of plastic components involve no/low defect contents and roughness levels in the nm-range for high gloss applications. Material properties as well as operating conditions influence the mould finish, and thus the final surface of moulded products. This paper focuses on how particle content and different polishing strategies influence final surface qualities of moulds. Visual estimations of polished tool steel samples were combined with non-contact 3D-surface texture analysis in order to correlate traditional assessments to more quantitative methods, and to be able to analyse the surfaces at nanometre-level. It was found that steels with a lower proportion of particles, like carbides and oxides, gave rise to smoother polished surfaces. In a comparative study of polishers from different polishing shops, it was found that while different surface preparation strategies can lead to similar final roughness, similar preparation techniques can produce high-quality surfaces from different steel grades. However, the non-contact 3D-surface texture analysis showed that not all smooth polished surfaces have desirable functional topographies for injection moulding of glossy plastic components.

  9. Experimental Investigation of Machining Parameters For Surface Roughness In High Speed CNC Turning of EN-24 Alloy Steel Using Response Surface Methodology

    Directory of Open Access Journals (Sweden)

    Puneet Saini

    2014-05-01

    Full Text Available Alloy Steel EN-24 (Medium Carbon Steel used in manufacturing of Automotive & aircraft components, Axles & Axles components, Shafts, Heavy duty Gears, Spindles, Studs, Pins, collets, bolts, couplings, sprockets, pinions & pinion arbors. Turning is the most common process used in manufacturing sector to produce smooth finish on cylindrical surfaces. Surface roughness is the important performance characteristics to be considered in the turning process is affected by several factors such as cutting tool material, spindle speed, feed rate, depth of cut and material properties. In this research Response surface methodology (RSM was applied to determine the optimum machining parameters leading to minimum surface roughness in turning process. The main purpose of this research is to study the effect of carbide inserts on EN-24 Alloy Steel surface by using three parameters (spindle speed, feed rate and depth of cut. This research was conducted by using 100 HS Stallion CNC Lathe machine. Seventeen sets of experiments were performed. In this work empirical models were developed for surface roughness by considering spindle speed, feed rate and depth of cut as main controlling factors using response surface methodology. The optimum value of the surface roughness (Ra comes out to be 0.48 µm. It is also concluded that feed rate is the most significant factor affecting surface roughness followed by depth of cut. As Cutting speed is the less significant factor affecting surface roughness. Optimum results are finally verified with the help of confirmation experiments. Keywords:

  10. Stormwater Priority Pollutants Versus Surface Water Quality Criteria

    DEFF Research Database (Denmark)

    Eriksson, Eva; Ledin, Anna; Baun, Anders

    2011-01-01

    Stormwater in urban areas comprises of a substantial part of the urban water cycle, dominating the flow in many small urban streams, and the pollution levels are sizeable. No stormwater quality criteria were found here and no European or national emission limit values exist. Stormwater pollutants...... however are present in levels exceeding most of the regulated surface water quality criteria and environmental quality standards. Therefore catchment characterisation is needed to chose suitable treatment prior to discharge into receiving surface waters, as the mixing may be insufficient in small streams....

  11. A new reactive atom plasma technology (RAPT) for precision machining: the etching of ULE optical surfaces

    Science.gov (United States)

    Fanara, Carlo; Shore, Paul; Nicholls, John R.; Lyford, Nicholas; Sommer, Phil; Fiske, Peter

    2006-06-01

    The next generation of 30-100 metre diameter extremely large telescopes (ELTs) requires large numbers of hexagonal primary mirror segments. As part of the Basic Technology programme run jointly by UCL and Cranfield University, a reactive atomic plasma technology (RAP(tm)) emerged from the US Lawrence Livermore National Laboratory (LLNL), is employed for the finishing of these surfaces. Results are presented on this novel etching technology. The Inductively Coupled Plasma (ICP) operated at atmospheric pressure using argon, activates the chemical species injected through its centre and promotes the fluorine-based chemical reactions at the surface. Process assessment trials on Ultra Low Expansion (ULE(tm)) plates, previously ground at high material removal rates, have been conducted. The quality of the surfaces produced on these samples using the RAP process are discussed. Substantial volumetric material removal rates of up to 0.446(21) mm 3/s at the highest process speed (1,200 mm/min) were found to be possible without pre-heating the substrate. The influences of power transfer, process speed and gas concentration on the removal rates have been determined. The suitability of the RAP process for revealing and removing sub-surface damage induced by high removal rate grinding is discussed. The results on SiC samples are reported elsewhere in this conference.

  12. An autonomous multisensor in situ metrology system for enabling high dynamic range measurement of 3D surfaces on precision machine tools

    Science.gov (United States)

    Liu, Samuel M. Y.; Cheung, Benny C. F.; Whitehouse, David; Cheng, Ching-Hsiang

    2016-11-01

    An in situ measurement is of prime importance when trying to maintain the position of the workpiece for further compensation processes in order to improve the accuracy and efficiency of the precision machining of three dimensional (3D) surfaces. However, the coordinates of most of the machine tools with closed machine interfaces and control system are not accessible for users, which make it difficult to use the motion axes of the machine tool for in situ measurements. This paper presents an autonomous multisensor in situ metrology system for enabling high dynamic range measurement of 3D surfaces on precision machine tools. It makes use of a designed tool path and an additional motion sensor to assist the registration of time-space data for the position estimation of a 2D laser scanner which measures the surface with a high lateral resolution and large area without the need to interface with the machine tool system. A prototype system was built and integrated into an ultra-precision polishing machine. Experimental results show that it measures the 3D surfaces with high resolution, high repeatability, and large measurement range. The system not only improves the efficiency and accuracy of the precision machining process but also extends the capability of machine tools.

  13. Dynamic Evaluation Model and Application Methods for Engineering Machine Maintenance Quality

    Institute of Scientific and Technical Information of China (English)

    WANG Jian; WANG Yan-feng; DAI Ling; WANG Xi

    2012-01-01

    It is an important content of equipment management to keep the engineering machine well. Based on the theory of component technology and grey related algorithm arithmetic, the requirements and procedures of engineering machine maintenance predicting process are analyzed, and a support object evaluation system is provided. The qualitative and quantitative indexes of evaluating process are fully taken into consideration to provide scientific methods and ways for proper evaluation and decision.

  14. Magnetic Electrochemical Finishing Machining

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    How to improve the finishing efficiency and surface roughness have been all along the objective of research in electrochemical polishing. However, the research activity, i.e. during electrochemical polishing, directly introduce the magnetic field to study how the magnetic field influences on the finishing efficiency, quality and the electrochemical process in the field of finishing machining technology, is insufficient. When introducing additional magnetic field in the traditional electrochemical pol...

  15. Swept Mechanism of Micro-Milling Tool Geometry Effect on Machined Oxygen Free High Conductivity Copper (OFHC) Surface Roughness.

    Science.gov (United States)

    Shi, Zhenyu; Liu, Zhanqiang; Li, Yuchao; Qiao, Yang

    2017-01-28

    Cutting tool geometry should be very much considered in micro-cutting because it has a significant effect on the topography and accuracy of the machined surface, particularly considering the uncut chip thickness is comparable to the cutting edge radius. The objective of this paper was to clarify the influence of the mechanism of the cutting tool geometry on the surface topography in the micro-milling process. Four different cutting tools including two two-fluted end milling tools with different helix angles of 15° and 30° cutting tools, as well as two three-fluted end milling tools with different helix angles of 15° and 30° were investigated by combining theoretical modeling analysis with experimental research. The tool geometry was mathematically modeled through coordinate translation and transformation to make all three cutting edges at the cutting tool tip into the same coordinate system. Swept mechanisms, minimum uncut chip thickness, and cutting tool run-out were considered on modeling surface roughness parameters (the height of surface roughness Rz and average surface roughness Ra) based on the established mathematical model. A set of cutting experiments was carried out using four different shaped cutting tools. It was found that the sweeping volume of the cutting tool increases with the decrease of both the cutting tool helix angle and the flute number. Great coarse machined surface roughness and more non-uniform surface topography are generated when the sweeping volume increases. The outcome of this research should bring about new methodologies for micro-end milling tool design and manufacturing. The machined surface roughness can be improved by appropriately selecting the tool geometrical parameters.

  16. THE METHOD OF ROLL SURFACE QUALITY MEASUREMENT FOR CONTINUOUS HOT DIP ZINC COATED STEEL SHEET PRODUCTION LINE

    Directory of Open Access Journals (Sweden)

    Ki Yong Choi

    2015-01-01

    Full Text Available The present paper describes a developed analyzing system of roll surface during the process of continuous hot dip zinc coated steel sheet production line, in particular, adhering problem by transferred inclusions from roll to steel sheet surface during annealing process so called the pickup. The simulated test machine for coated roll surface in processing line has been designed and performed. The system makes it possible to analyze roll surface condition according to pickup phenomena from various roll coatings concerning operating conditions of hearth rolls in annealing furnace. The algorithm of fast pickup detection on surface is developed on the base of processing of several optical images of surface. The parameters for quality estimation of surface with pickups were developed. The optical system for images registration and image processing electronics may be used in real time and embed in processing line.

  17. Chatter and machine tools

    CERN Document Server

    Stone, Brian

    2014-01-01

    Focussing on occurrences of unstable vibrations, or Chatter, in machine tools, this book gives important insights into how to eliminate chatter with associated improvements in product quality, surface finish and tool wear. Covering a wide range of machining processes, including turning, drilling, milling and grinding, the author uses his research expertise and practical knowledge of vibration problems to provide solutions supported by experimental evidence of their effectiveness. In addition, this book contains links to supplementary animation programs that help readers to visualise the ideas detailed in the text. Advancing knowledge in chatter avoidance and suggesting areas for new innovations, Chatter and Machine Tools serves as a handbook for those desiring to achieve significant reductions in noise, longer tool and grinding wheel life and improved product finish.

  18. ENVELOPING THEORY BASED METHOD FOR THE DETERMINATION OF PATH INTERVAL AND TOOL PATH OPTIMIZATION FOR SURFACE MACHINING

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    An enveloping theory based method for the determination of path interval in three-axis NC machining of free form surface is presented, and a practical algorithm and the measures for improving the calculating efficiency of the algorithm are given. Not only the given algorithm can be used for ball end cutter, flat end cutter, torus cutter and drum cutter, but also the proposed method can be extended to arbitrary milling cutters. Thus, the problem how to strictly calculate path interval in the occasion of three-axis NC machining of free form surfaces with non-ball end cutters has been resolved effectively. On this basis, the factors that affect path interval are analyzed, and the methods for optimizing tool path are explored.

  19. Prediction of water surface elevation of Great Salt Lake using Support Vector Machine

    Science.gov (United States)

    Shrestha, N. K.; Urroz, G.

    2009-12-01

    Record breaking rises of Great Salt Lake (GSL) water levels that were observed in the period 1982-1987 resulted in severe economic impact to the State of Utah. Rising lake levels caused flooding that damaged highways, railways, recreation facilities and industries located in exposed lake bed. Prediction of GSL water levels necessitates the development of a model for accurate predictions of such levels in order to reduce or prevent economic loss due to flooding as happened in the past. A data-driven model, whose intent is to determine the relationship between inputs and outputs without knowing underlying physical process, was used in this project. A data-driven model can bridge the gap between classical regression-based and physically-based hydrological models. A Support Vector Machines (SVM) was used to predict water surface elevation of the GSL. The SVM-based reconstruction was used to develop time series forecast for multiple lead times. The model is able to extract the dynamics of the system by using only a few observed data points for training. The reliability of the algorithm in learning and forecasting the dynamics of the system was tested by changing two parameters: the integer time lag and the dimension (d) of the system. Parameter tau models the delay in which the dynamics unfolds by creating vectors of dimension d out of single measurements. For a given set of parameters tau and d, the discrepancy between observation and prediction is reduced by changing the cost parameter and a parameter called epsilon that controls the width of the SVM insensitive zone. All the data points within the epsilon insensitive zone are neglected in the SVM analysis. The analysis was performed for two time periods. The period of 1982 to 1987 was used to test the model performance in predicting the corresponding dramatic rise of GSL elevation. The period of 1987 to 2008 was used to test the performance of model for the normal water level rise and fall of the GSL. This analysis

  20. The surface quality of AWJ cut parts as a function of abrasive material reusing rate

    Science.gov (United States)

    Schnakovszky, C.; Herghelegiu, E.; Radu, M. C.; Tampu, N. C.

    2015-11-01

    Abrasive water jet cutting (AWJ) has been extensively used during the last years to process a large variety of materials since it offers important advantages as a good quality of the processed surface, without heat affected zones, low environmental impact (no emission of dust or other compounds that endanger the health of the user), small induced mechanical stresses etc. The main disadvantage is the high cost of processing (cost of equipment and consumables). In view of this, the effects of reusing the abrasive material on the quality of processed surface are investigated in this paper. Two steel materials were used: OL 37 (S 235) with large applicability in machine building industry and 2P armor steel used in the arms industry. The reusing rate of the garnet abrasive material was: 0%, 20%, 40%, 60%, 80% and 100%. The quality of processed surface was quantified by the following parameters: width at the jet inlet (Li), width at the jet outlet (Lo), inclination angle (α), deviation from perpendicularity (u) and roughness (Ra).

  1. Third-order point contact approach for five-axis sculptured surface machining using non-ball-end tools(II): Tool positioning strategy

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Based on the mathematical model describing the third-order approximation of the cutter envelope surface according to one given cutter location(CL),a tool positioning strategy is proposed for efficiently machining free-form surfaces with non-ball-end cutters.The optimal CL is obtained by adjusting the inclination and tilt angles of the cutter until its envelope surface and the design surface have the third-order contact at the cutter contact(CC)point,which results in a wide machining strip.The strategy can handle the constraints of machine joint angle limits,global collision avoidance and tool path smoothness in a nature way,and can be applied to general rotary cutters and complex surfaces.Numerical examples demonstrate that the third-order point contact approach can improve the machining strip width greatly as compared with the recently reported second-order one.

  2. Extreme learning machines: a new approach for modeling dissolved oxygen (DO) concentration with and without water quality variables as predictors.

    Science.gov (United States)

    Heddam, Salim; Kisi, Ozgur

    2017-07-01

    In this paper, several extreme learning machine (ELM) models, including standard extreme learning machine with sigmoid activation function (S-ELM), extreme learning machine with radial basis activation function (R-ELM), online sequential extreme learning machine (OS-ELM), and optimally pruned extreme learning machine (OP-ELM), are newly applied for predicting dissolved oxygen concentration with and without water quality variables as predictors. Firstly, using data from eight United States Geological Survey (USGS) stations located in different rivers basins, USA, the S-ELM, R-ELM, OS-ELM, and OP-ELM were compared against the measured dissolved oxygen (DO) using four water quality variables, water temperature, specific conductance, turbidity, and pH, as predictors. For each station, we used data measured at an hourly time step for a period of 4 years. The dataset was divided into a training set (70%) and a validation set (30%). We selected several combinations of the water quality variables as inputs for each ELM model and six different scenarios were compared. Secondly, an attempt was made to predict DO concentration without water quality variables. To achieve this goal, we used the year numbers, 2008, 2009, etc., month numbers from (1) to (12), day numbers from (1) to (31) and hour numbers from (00:00) to (24:00) as predictors. Thirdly, the best ELM models were trained using validation dataset and tested with the training dataset. The performances of the four ELM models were evaluated using four statistical indices: the coefficient of correlation (R), the Nash-Sutcliffe efficiency (NSE), the root mean squared error (RMSE), and the mean absolute error (MAE). Results obtained from the eight stations indicated that: (i) the best results were obtained by the S-ELM, R-ELM, OS-ELM, and OP-ELM models having four water quality variables as predictors; (ii) out of eight stations, the OP-ELM performed better than the other three ELM models at seven stations while the R

  3. Surface texturing of Si3N4–SiC ceramic tool components by pulsed laser machining

    CSIR Research Space (South Africa)

    Tshabalala, LC

    2016-03-01

    Full Text Available is often accompanied by numerous shortcomings which either lead to poor surface quality or residual surface damage of the workpiece. In this sense, this work focuses on the application of a pulsed mode, nanosecond Nd:YAG laser system for the surface...

  4. Study on Influensive Factors on Surface Quality and Edges of Through- Holes Bored in Particleboard and MDF

    Directory of Open Access Journals (Sweden)

    Abolghasem Khazaian

    2012-06-01

    Full Text Available In this research, effects of different factors in the CNC machine through- Hole boring of MDF and particleboard were investigated. Variables in boring were selected bit diameter in 3 levels 5,10 and 15 mm, feed speed in 2 levels 0.3 m/min and 0.6 m/min and rotary speed of machine axis in 3 levels 300,1500 and 3000 rmp. The goal of this study was to measure effects of mentioned factors on edge- quality of through- holes made in particle- board and MDF. Results have shown that with all bit diameters used, increasing rotary speed of bit improves smoothness of holes in both sides and boring dusts turned to finer sizes. Increasing feed speed did show positive effect on edge surface quality and lowered burr formation.

  5. Compare and Selection of Surface Rough Machining Methods Based on MasterCAM%基于MasterCAM的曲面粗加工方法的比较与选择

    Institute of Scientific and Technical Information of China (English)

    佛新岗

    2012-01-01

    以动物头投影曲面为研究对象,通过MasterCAM和NCSENTRY软件进行多种曲面粗加工方法的比较研究,为MasterCAM使用者提供了在保障零件加工质量和效率的前提下如何选择曲面粗加工方式的方法.%Taking the projection surface of an animal head as research object, the various surface rough machining methods were compared by using MasterCAM and NCSENTRY. By the research results, how to choose the surface rough machining methods is known on the premise of assuring quality and efficiency of processing.

  6. A Gradient-Simulated Annealing Algorithm of Pre-location-Based Best Fitting of Blank to Complex Surfaces Machining

    Institute of Scientific and Technical Information of China (English)

    MALi-ming; JIANGHong; WANGXiao-chun

    2004-01-01

    The algorithm is divided into two steps. The first step pre-locates the blank by aligning its centre of gravity and approximate normal vector with those of destination surfaces, with largest overlap of projections of two objects on a plane perpendicular to the normal vector. The second step is optimizing an objective function by means of gradient-simulated annealing algorithm to get the best matching of a set of distributed points on the blank and destination surfaces. An example for machining hydroelectric turbine blades is given to verify the effectiveness of algorithm.

  7. Grow Large High-Quality Diamonds with Different Seed Surfaces

    Institute of Scientific and Technical Information of China (English)

    ZANG Chuan-Yi; JIA Xiao-Peng; MA Hong-An; LI Shang-Sheng; TIAN Yu; XIAO Hong-Yu

    2006-01-01

    Large high-quality type Ib diamond crystals have been grown with different seed surfaces by temperature gradient method at 5.5GPa, 1500-1600K, with NiMnCo alloy as the metal solvent. Compared with {100} as the growth surface, the growth region of large high-quality diamond crystals with {111} as the growth surface at a higher growth rate shifts markedly from lower temperatures (suitable for {100}-facet growth) to higher temperatures (suitable for {lll}-facet growth). However, regardless of different growth surfaces, {100} or {111}, the grown crystals of sheet-shaped shape are most difficult for metal inclusions to be trapped into, and whether or not matched growth between the seed surfaces and the growth temperatures determines the crystal shapes. In view of the growth rates, large high-quality diamond crystals of sheet-shaped shapes can be grown at a growth rate of above 2.5mg/h, while the growth rate of large high-quality diamond crystals should not be beyond 1.5mg/h for tower-shaped crystals.

  8. Improving the quality of automated DVD subtitles via example-based machine translation

    DEFF Research Database (Denmark)

    Armstrong, Stephen; Caffrey, Colm; Flanagan, Marian

    Denoual (2005) discovered that, contrary to popular belief, an Example-Based Machine Translation system trained on heterogeneous data produced significantly better results than a system trained on homogeneous data. Using similar evaluation metrics and a few additional ones, in this paper we show ...

  9. The effect of TWD estimation error on the geometry of machined surfaces in micro-EDM milling

    DEFF Research Database (Denmark)

    Puthumana, Govindan; Bissacco, Giuliano; Hansen, Hans Nørgaard

    In micro EDM (electrical discharge machining) milling, tool electrode wear must be effectively compensated in order to achieve high accuracy of machined features [1]. Tool wear compensation in micro-EDM milling can be based on off-line techniques with limited accuracy such as estimation....... The error propagation effect is demonstrated through a software simulation tool developed by the authors for determination of the correct TWD for subsequent use in compensation of electrode wear in EDM milling. The implemented model uses an initial arbitrary estimation of TWD and a single experiment...... and statistical characterization of the discharge population [3]. The TWD based approach permits the direct control of the position of the tool electrode front surface. However, TWD estimation errors will generate a self-amplifying error on the tool electrode axial depth during micro-EDM milling. Therefore...

  10. Finish machining of hardened gears wheels using cubic boron nitride (CBN inserts

    Directory of Open Access Journals (Sweden)

    R. Talar

    2012-04-01

    Full Text Available The paper presents some results of investigation of finish machining of hardened bearing surfaces of cylindrical gear wheels. Finish machining has been performed with wedges of defined geometry made of CBN. The presented investigation results are related mainly to the wear processes of the cutting wedges. Additional results of quality examination of finish machined gear wheels have been presented, too.

  11. A uniform, quality controlled Surface Ocean CO2 Atlas (SOCAT

    Directory of Open Access Journals (Sweden)

    T. Takahashi

    2012-08-01

    Full Text Available A well documented, publicly available, global data set of surface ocean carbon dioxide (CO2 parameters has been called for by international groups for nearly two decades. The Surface Ocean CO2 Atlas (SOCAT project was initiated by the international marine carbon science community in 2007 with the aim of providing a comprehensive, publicly available, regularly updated, global data set of marine surface CO2, which had been subject to quality control (QC. Many additional CO2 data, not yet made public via the Carbon Dioxide Information Analysis Center (CDIAC, were retrieved from data originators, public websites and other data centres. All data were put in a uniform format following a strict protocol. Quality control was carried out according to clearly defined criteria. Regional specialists performed the quality control, using state-of-the-art web-based tools, specially developed for accomplishing this global team effort. SOCAT version 1.5 was made public in September 2011 and holds 6.3 million quality controlled surface CO2 data points from the global oceans and coastal seas, spanning four decades (1968–2007. Three types of data products are available: individual cruise files, a merged complete data set and gridded products. With the rapid expansion of marine CO2 data collection and the importance of quantifying net global oceanic CO2 uptake and its changes, sustained data synthesis and data access are priorities.

  12. A uniform, quality controlled Surface Ocean CO2 Atlas (SOCAT

    Directory of Open Access Journals (Sweden)

    B. Pfeil

    2013-04-01

    Full Text Available A well-documented, publicly available, global data set of surface ocean carbon dioxide (CO2 parameters has been called for by international groups for nearly two decades. The Surface Ocean CO2 Atlas (SOCAT project was initiated by the international marine carbon science community in 2007 with the aim of providing a comprehensive, publicly available, regularly updated, global data set of marine surface CO2, which had been subject to quality control (QC. Many additional CO2 data, not yet made public via the Carbon Dioxide Information Analysis Center (CDIAC, were retrieved from data originators, public websites and other data centres. All data were put in a uniform format following a strict protocol. Quality control was carried out according to clearly defined criteria. Regional specialists performed the quality control, using state-of-the-art web-based tools, specially developed for accomplishing this global team effort. SOCAT version 1.5 was made public in September 2011 and holds 6.3 million quality controlled surface CO2 data points from the global oceans and coastal seas, spanning four decades (1968–2007. Three types of data products are available: individual cruise files, a merged complete data set and gridded products. With the rapid expansion of marine CO2 data collection and the importance of quantifying net global oceanic CO2 uptake and its changes, sustained data synthesis and data access are priorities.

  13. Are different generations of CAD/CAM milling machines capable to produce restorations with similar quality?

    Science.gov (United States)

    Roperto, Renato; Assaf, Hussein; Soares-Porto, Thiago; Lang, Lisa; Teich, Sorin

    2016-01-01

    Background Different CAD/CAM machines’ generation may impact the restoration overall quality. The present study evaluated the marginal fit of CAD/CAM restorations manufactured with different generations of CEREC milling unit systems. Material and Methods Sixteen typodont teeth were divided into two groups (n=8) according to the machine’s generation assigned. These are control group (G1): Cerec AC with Bluecam/Cerec 3 milling unit and (G2): Cerec AC with Bluecam/MC XL Premium Package milling unit. Scanning of the preparation were performed and crowns were milled using the Vita Mark II blocks. Blocks were cemented using epoxy glue on the pulpal floor only and finger pressure applied for 1 min. Upon completion of the cementation step, misfits between the restoration and abutment were measured by microphotography and the silicone replica technique using light body silicon material on Mesial (M) and Distal (D) surfaces. Results Mean and SDs of marginal gaps in micrometers were: G1/M: 94.90 (±38.52), G1/D: 88.53 (±44.87), G2/M: 85.65 (±29.89), G2/D: 95.28 (±28.13). Two-way ANOVA indicated no significant differences among different groups (P>0.05); surface area (P>0.05) and the interaction (P>0.05). Overall, G2 had greater margin gaps than G1, however, without statistical difference (P>0.05). Conclusions Difference in milling unit generation did not significantly affect the marginal fit. Marginal gap means were in the range of the clinical acceptance levels for both generations of Cerec milling units, regardless the teeth site area. Key words:CAD/CAM, margin, ceramics. PMID:27703611

  14. Surface treatment by electric discharge machining of Ti-6Al-4V alloy for potential application in orthopaedics.

    Science.gov (United States)

    Harcuba, Petr; Bačáková, Lucie; Stráský, Josef; Bačáková, Markéta; Novotná, Katarína; Janeček, Miloš

    2012-03-01

    This study investigated the properties of Ti-6Al-4V alloy after surface treatment by the electric discharge machining (EDM) process. The EDM process with high peak currents proved to induce surface macro-roughness and to cause chemical changes to the surface. Evaluations were made of the mechanical properties by means of tensile tests, and of surface roughness for different peak currents of the EDM process. The EDM process with peak current of 29 A was found to induce sufficient surface roughness, and to have a low adverse effect on tensile properties. The chemical changes were studied by scanning electron microscopy equipped with an energy dispersive X-ray analyser (EDX). The surface of the benchmark samples was obtained by plasma-spraying a titanium dioxide coating. An investigation of the biocompatibility of the surface-treated Ti-6Al-4V samples in cultures of human osteoblast-like MG 63 cells revealed that the samples modified by EDM provided better substrates for the adhesion, growth and viability of MG 63 cells than the TiO2 coated surface. Thus, EDM treatment can be considered as a promising surface modification to orthopaedic implants, in which good integration with the surrounding bone tissue is required.

  15. Quality-productivity decision making when turning of Inconel 718 aerospace alloy: A response surface methodology approach

    Directory of Open Access Journals (Sweden)

    Hamid Tebassi

    2017-06-01

    Full Text Available Inconel 718 is among difficult to machine materials because of its abrasiveness and high strength even at high temperature. This alloy is mainly used in aircraft and aerospace industries. Therefore, it is very important to reveal and evaluate cutting tools behavior during machining of this kind of alloy. The experimental study presented in this research work has been carried out in order to elucidate surface roughness and productivity mathematical models during turning of Inconel 718 superalloy (35 HRC with SiC Whisker ceramic tool at various cutting parameters (depth of cut, feed rate, cutting speed and radius nose. A small central composite design (SCCD including 16 basics runs replicated three times (48 runs, was adopted and graphically evaluated using Fraction of design space (FDS graph, completed by a statistical analysis of variance (ANOVA. Mathematical models for surface roughness and productivity were developed and normality was improved using the Box-Cox transformation. Results show that surface roughness criterion Ra was mainly influenced by cutting speed, radius nose and feed rate, and that the depth of cut had major effect on productivity. Finally, ranges of optimized cutting conditions were proposed for serial industrial production. Industrial benefit was illustrated in terms of high surface quality accompanied with high productivity. Indeed, results show that the use of optimal cutting condition had an industrial benefit to 46.9 % as an improvement in surface quality Ra and 160.54 % in productivity MRR.

  16. Laser machining of explosives

    Science.gov (United States)

    Perry, Michael D.; Stuart, Brent C.; Banks, Paul S.; Myers, Booth R.; Sefcik, Joseph A.

    2000-01-01

    The invention consists of a method for machining (cutting, drilling, sculpting) of explosives (e.g., TNT, TATB, PETN, RDX, etc.). By using pulses of a duration in the range of 5 femtoseconds to 50 picoseconds, extremely precise and rapid machining can be achieved with essentially no heat or shock affected zone. In this method, material is removed by a nonthermal mechanism. A combination of multiphoton and collisional ionization creates a critical density plasma in a time scale much shorter than electron kinetic energy is transferred to the lattice. The resulting plasma is far from thermal equilibrium. The material is in essence converted from its initial solid-state directly into a fully ionized plasma on a time scale too short for thermal equilibrium to be established with the lattice. As a result, there is negligible heat conduction beyond the region removed resulting in negligible thermal stress or shock to the material beyond a few microns from the laser machined surface. Hydrodynamic expansion of the plasma eliminates the need for any ancillary techniques to remove material and produces extremely high quality machined surfaces. There is no detonation or deflagration of the explosive in the process and the material which is removed is rendered inert.

  17. Characterization of electric discharge machining, subsequent etching and shot-peening as a surface treatment for orthopedic implants

    Energy Technology Data Exchange (ETDEWEB)

    Stráský, Josef, E-mail: josef.strasky@gmail.com [Charles University, Department of Physics of Materials (Czech Republic); Havlíková, Jana; Bačáková, Lucie [Institute of Physiology, Academy of Sciences of the Czech Republic (Czech Republic); Harcuba, Petr [Charles University, Department of Physics of Materials (Czech Republic); Mhaede, Mansour [Clausthal University of Technology, Institute of Materials Science and Engineering (Germany); Faculty of Engineering, Zagazig University (Egypt); Janeček, Miloš [Charles University, Department of Physics of Materials (Czech Republic)

    2013-09-15

    Presented work aims at multi-method characterization of combined surface treatment of Ti–6Al–4V alloy for biomedical use. Surface treatment consists of consequent use of electric discharge machining (EDM), acid etching and shot peening. Surface layers are analyzed employing scanning electron microscopy and energy dispersive X-ray spectroscopy. Acid etching by strong Kroll's reagent is capable of removing surface layer of transformed material created by EDM. Acid etching also creates partly nanostructured surface and significantly contributes to the enhanced proliferation of the bone cells. The cell growth could be positively affected by the superimposed bone-inspired structure of the surface with the morphological features in macro-, micro- and nano-range. Shot peening significantly improves poor fatigue performance after EDM. Final fatigue performance is comparable to benchmark electropolished material without any adverse surface effect. The proposed three-step surface treatment is a low-cost process capable of producing material that is applicable in orthopedics.

  18. Wheel wear and surface/subsurface qualities when precision grinding optical materials

    Science.gov (United States)

    Tonnellier, X.; Shore, P.; Luo, X.; Morantz, P.; Baldwin, A.; Evans, R.; Walker, D.

    2006-06-01

    An ultra precision large optics grinder, which will provide a rapid and economic solution for grinding large off-axis aspherical and free-form optical components, has been developed at Cranfield University. This paper presents representative grinding experiments performed on another machine - a 5 axes Edgetek - in order to verify the proposed BoX(r) grinding cycle. The optical materials assessed included; Zerodur(r), SIC and ULE(r), all three being materials are candidates for extreme large telescope (ELT) mirror segments. Investigated removal rates ranged from 2mm 3/s to 200mm 3/s. The higher removal rate ensures that a 1 metre size optic could be ground in less than 10 hours. These experiments point out the effect of diamond grit size on the surface quality and wheel wear. The power and forces for each material type at differing removal rates are presented, together with subsurface damage.

  19. MM99.50 - Surface Topography Characterization Using an Atomic Force Microscope Mounted on a Coordinate Measuring Machine

    DEFF Research Database (Denmark)

    Chiffre, Leonardo De; Hansen, Hans Nørgaard; Kofod, Niels

    1999-01-01

    The paper describes the construction, testing and use of an integrated system for topographic characterization of fine surfaces on parts having relatively big dimensions. An atomic force microscope (AFM) was mounted on a manual three-coordinate measuring machine (CMM) achieving free positioning o...... areas traced in single scans of 40 mu m x 40 mu m. The results show that surface mapping on industrial surfaces is possible using the Least Mean Square alignment provided by the AFM software....... values in the order of 1 nm. The positioning repeatability of the two horizontal axes of the CMM was determined to +/-1 mu m. Sets of four 20 mu m x 20 mu m areas were traced on fiat objects, combining the data into single 40 mu m x 40 mu m areas, and comparing the roughness values to those for the same...

  20. Applications of high power lasers. [using reflection holograms for machining and surface treatment

    Science.gov (United States)

    Angus, J. C.

    1979-01-01

    The use of computer generated, reflection holograms in conjunction with high power lasers for precision machining of metals and ceramics was investigated. The Reflection holograms which were developed and made to work at both optical wavelength (He-Ne, 6328 A) and infrared (CO2, 10.6) meet the primary practical requirement of ruggedness and are relatively economical and simple to fabricate. The technology is sufficiently advanced now so that reflection holography could indeed be used as a practical manufacturing device in certain applications requiring low power densities. However, the present holograms are energy inefficient and much of the laser power is lost in the zero order spot and higher diffraction orders. Improvements of laser machining over conventional methods are discussed and addition applications are listed. Possible uses in the electronics industry include drilling holes in printed circuit boards making soldered connections, and resistor trimming.

  1. Online tomato sorting based on shape, maturity, size, and surface defects using machine vision

    OpenAIRE

    ARJENAKI, Omid Omidi; MOGHADDAM, Parviz Ahmadi; MOTLAGH, Asad Moddares

    2013-01-01

    Online sorting of tomatoes according to their features is an important postharvest procedure. The purpose of this research was to develop an efficient machine vision-based experimental sorting system for tomatoes. Relevant sorting parameters included shape (oblong and circular), size (small and large), maturity (color), and defects. The variables defining shape, maturity, and size of the tomatoes were eccentricity, average of color components, and 2-D pixel area, respectively. Tomato defects ...

  2. Physico-chemical surface characterization of a bacterial population isolated from a milking machine

    OpenAIRE

    Teixeira, P.; Lopes, Zulmira; Azeredo, Joana; Oliveira, Rosário; Vieira, M. J.

    2005-01-01

    The hydrophobicity of 26 species of bacteria representative of the main genera isolated from a rubber short milk tube, which is a constituent of a cluster from a milking machine, was determined. The materials forming the cluster namely rubber, stainless steel (SS) 316, stainless steel (SS) 304, glass and polymethylmethacrylate (PMMA) were also assayed in terms of hydrophobicity. In relation with the hydrophobicity of bacteria, all the strains of Lactobacillus lactis lactis as well as...

  3. Estimation of Surface Soil Moisture in Irrigated Lands by Assimilation of Landsat Vegetation Indices, Surface Energy Balance Products, and Relevance Vector Machines

    Directory of Open Access Journals (Sweden)

    Alfonso F. Torres-Rua

    2016-04-01

    Full Text Available Spatial surface soil moisture can be an important indicator of crop conditions on farmland, but its continuous estimation remains challenging due to coarse spatial and temporal resolution of existing remotely-sensed products. Furthermore, while preceding research on soil moisture using remote sensing (surface energy balance, weather parameters, and vegetation indices has demonstrated a relationship between these factors and soil moisture, practical continuous spatial quantification of the latter is still unavailable for use in water and agricultural management. In this study, a methodology is presented to estimate volumetric surface soil moisture by statistical selection from potential predictors that include vegetation indices and energy balance products derived from satellite (Landsat imagery and weather data as identified in scientific literature. This methodology employs a statistical learning machine called a Relevance Vector Machine (RVM to identify and relate the potential predictors to soil moisture by means of stratified cross-validation and forward variable selection. Surface soil moisture measurements from irrigated agricultural fields in Central Utah in the 2012 irrigation season were used, along with weather data, Landsat vegetation indices, and energy balance products. The methodology, data collection, processing, and estimation accuracy are presented and discussed.

  4. A new geometrical construction using rounded surfaces proposed for the transverse flux machine for direct drive wind turbine

    DEFF Research Database (Denmark)

    Argeseanu, Alin; Nica, Florin Valentin Traian; Ritchie, Ewen;

    2014-01-01

    This paper proposes a new construction for transverse flux machines (TFM) using a rounded surfaces core geometry. The new concept has been developed for TFM with U core geometry. In this case a new analytic design procedure was proposed. The analytic design of the new TFM construction is further...... improved by FEM modelling and analysis. Using the new concept, a significant reduction of the active materials is obtained. The innovative geometry also provides a uniform magnetic field in the core structure. According to the comparison of both the TFM with prismatic and rounded core geometries the new...

  5. RESEARCH ON MODELING AND CHARACTERISTICS OF THE SPINDLE DYNAMIC COUPLING ABSORBERING SYSTEM OF A SUPER-PRECISION SURFACE GRINDING MACHINE

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The bearing is described by constrain matrix, and the spindle system of a NC surface grinding machine is simplified as elastic-coupling beam, then modal synthesis method is used to establish the dynamic model of beam.Moreover, the response of the end of rotor is analyzed, and the natural frequency, principle mode and other dynamic characteristics of the coupling system are studied, the law of bearing stiffness to coupling frequency and amplitude of rotor is also found.Finally, according to the actual condition, a dynamic absorber is designed.The simulation and experimental results show that the amplitude of spindle can be declined effectively when the dynamic absorber is attached.

  6. KWARTA (Quality Assurance in the Radiotherapy centres of the Antwerp province): Quality control of the contract therapy machine and treatment planning system

    Energy Technology Data Exchange (ETDEWEB)

    De Ost, B.; Schaeken, B.; Vanregemorter, J. [Algemeen Ziekenhuis Middelheim, Antwerp (Belgium); Bellekens, L. [Sint-Vincentius Ziekenhuis, Antwerp (Belgium); Cardoen, R.; Pieters, D. [Medisch Instituut Sint Augustinus, Wilrijk (Belgium); Goossens, H. [Sint-Elisabeth Ziekenhuis, Turnhout (Belgium); Haest, K.; Mertens, N. [Sint Norbertus Ziekenhuis, Duffel (Belgium)

    1995-12-01

    During the first year of the provincial QA project, joint procedures were set up for the routine quality control of linear accelerators, Cobalt treatment machines and simulators. A set of standard forms was produced for use in all centres, respecting the differences in each individual machine. Since forms are now in use in all centres, the second year of the project mainly focused on the QA/QC of the contract therapy machine and treatment planning system. QC measurements for the contract therapy machines were performed in air or in a phantom. Since the output was checked with the same ionisation chamber (0.33 cc flat chamber calibrated for 50 kV) and the same type of electrometer in all centres, the results could be compared mutually and with the reference values. The major parameter groups, tested for the treatment planning system were: isodose distribution (visual control of all square fields in the database of the system), PDD data (analysing of 10 x 10 cm{sup 2}, 20 x 20 cm{sup 2}, 30 x 30 cm{sup 2} and 40 x 40 cm{sup 2} open or wedged fields), output factors, wedge and tray factors, inverse square law, geometrical testing of the digitizer - screen - printer and geometrical and densitometrical testing of the CT images - screen - printer. Between 496 and 1243 parameters were investigated in the different centres (depending on the presence of the electron data). Irregularities (0 % to 4 % of the total investigated parameters) were reported to the respective physicist.

  7. Study on the effect of thermal property of metals in ultrasonic-assisted laser machining

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hu Seung; Kim, Gun Woo; Park, Jong Eun [Dept. of Mechanical Engineering, Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of); Cho, Sung Hak; Yang, Min Yang; Park, Jong Kweon [Korea Institute of Machinery and Materials, Deajeon (Korea, Republic of)

    2015-08-15

    The laser machining process has been proposed as an advanced process for the selective fabrication of electrodes without a mask. In this study, we adapt laser machining to metals that have different thermal properties. Based on the results, the metals exhibit a different surface morphology, heat-affected zone (HAZ), and a recast layer around the machined surface according to their thermal conductivity, boiling point, and thermal diffusivity. Then, we apply ultrasonic-assisted laser machining to remove the recast layer. The ultrasonic-assisted laser machining exhibits a better surface quality in metals with higher diffusivity than those having lower diffusivity.

  8. Electrochemical Machining – Special Equipment and Applications in Aircraft Industry

    Directory of Open Access Journals (Sweden)

    Ruszaj Adam

    2016-06-01

    Full Text Available Electrochemical machining is an unique method of shaping in which, for optimal parameters tool has no wear, surface layer properties after machining are similar to the core material and surface quality and accuracy increase together with material removal rate increase. Such advantages of electrochemical machining, besides of some ecological problems, create industry interest in the range of manufacturing elements made of materials with special properties (i.e. turbine blades of flow aircrafts engines. In the paper the nowadays possibilities and recent practical application of electrochemical machining in aircraft have been presented.

  9. Scanning compound surfaces with no existing CAD model by using laser probe of a coordinate measuring machine

    Science.gov (United States)

    Che, Chenggang

    1992-09-01

    In recent years, the manufacturing of parts with compound surfaces relies more and more on computer integrated manufacturing (CIM) because of the ever increasing complexity of surface features. For a standard CIM cycle, it starts from a computer aided design (CAD) model which was designed previously be experienced mechanical drafters. The CAD model is then interpreted as numerical controlled (NC) machining codes according to which the part is finally manufactured, this is usually referred to as the normal manufacturing process in Figure 1. However, in many cases, a CAD model of a part is not always readily available to begin the CIM cycle. For instance, in automobile industry, the development of new car models takes a long time from concept to model because of the tedious manual digitization process. Also, in some other cases, the mechanical design of a product may need frequent modification, such as ship hulls, aeroplane fuselages, wings and turbine blades, etc. This was traditionally done by copymilling of a master model. In a computer aided manufacturing (CAM) environment, a mathematical model or representation of a part is required to begin a CIM cycle. The automation of the whole manufacturing system requires a rapid part modeling tool. Fortunately, this becomes possible with the advent of recent development in optical sensing devices and many non-contact sensing techniques. Before a part model is established, surface digitization should first be implemented so that enough measurement points can be fitted later, and this is the most important step of the reverse engineering process as in Figure 1. And also, it is obvious that the efficiency and accuracy of the surface modeling relies heavily on the efficiency and accuracy of the surface digitization. The present paper aims at achieving surface digitization accurately and rapidly with a coordinate measurement machine (CMM) and an inexpensive laser range-finding probe. By making full use of the control system of

  10. [NIR spectroscopy based on least square support vector machines for quality prediction of tomato juice].

    Science.gov (United States)

    Huang, Kang; Wang, Hui-jun; Xu, Hui-rong; Wang, Jian-ping; Ying, Yi-bin

    2009-04-01

    The application of least square support vector machines (LS-SVM) regression method based on statistics study theory to the analysis with near infrared (NIR) spectra of tomato juice was introduced in the present paper. In this method, LS-SVM was used for establishing model of spectral analysis, and was applied to predict the sugar contents (SC) and available acid (VA) in tomato juice samples. NIR transmission spectra of tomato juice were measured in the spectral range of 800-2,500 nm using InGaAs detector. The radial basis function (RBF) was adopted as a kernel function of LS-SVM. Sixty seven tomato juice samples were used as calibration set, and thirty three samples were used as validation set. The results of the method for sugar contents (SC) and available acid (VA) prediction were: a high correlation coefficient of 0.9903 and 0.9675, and a low root mean square error of prediction (RMSEP) of 0.0056 degree Brix and 0.0245, respectively. And compared to PLS and PCR methods, the performance of the LSSVM method was better. The results indicated that it was possible to built statistic models to quantify some common components in tomato juice using near-infrared (NIR) spectroscopy and least square support vector machines (LS-SVM) regression method as a nonlinear multivariate calibration procedure, and LS-SVM could be a rapid and accurate method for juice components determination based on NIR spectra.

  11. Experimental investigation on the effects of cooling system on surface quality in high speed milling of an aluminium alloy

    Science.gov (United States)

    Chirita, B.; Tampu, N. C.; Brabie, G.; Radu, M. C.

    2016-08-01

    Surface quality is often an important feature of industrial products, not only from the impact it has on the aesthetic aspect but also for the functional role of the parts. High quality surface increases corrosion resistance, assures a longer life cycle for the product and lowers the wear. For a machined part, surface quality is influenced by a series of factors such as the material of the part, the process type, tool geometry, cutting parameters or the cooling system. The choice of the cooling system is especially important, taking into account that the proper conditions will not only assure a superior surface quality, but will also lower the costs and reduce the environmental impact and health risks. The present study aims to investigate the performance of the cooling system and the effect of the cutting parameters on the characteristics of the surfaces resulted from high speed face milling of some parts made of Al 7050-T7451 aluminium alloy. Dry cutting conditions and minimum quantity lubrication (MQL) where used. The results were analysed using analysis of variance (ANOVA).

  12. A finite state machine read-out chip for integrated surface acoustic wave sensors

    Science.gov (United States)

    Rakshit, Sambarta; Iliadis, Agis A.

    2015-01-01

    A finite state machine based integrated sensor circuit suitable for the read-out module of a monolithically integrated SAW sensor on Si is reported. The primary sensor closed loop consists of a voltage controlled oscillator (VCO), a peak detecting comparator, a finite state machine (FSM), and a monolithically integrated SAW sensor device. The output of the system oscillates within a narrow voltage range that correlates with the SAW pass-band response. The period of oscillation is of the order of the SAW phase delay. We use timing information from the FSM to convert SAW phase delay to an on-chip 10 bit digital output operating on the principle of time to digital conversion (TDC). The control inputs of this digital conversion block are generated by a second finite state machine operating under a divided system clock. The average output varies with changes in SAW center frequency, thus tracking mass sensing events in real time. Based on measured VCO gain of 16 MHz/V our system will convert a 10 kHz SAW frequency shift to a corresponding mean voltage shift of 0.7 mV. A corresponding shift in phase delay is converted to a one or two bit shift in the TDC output code. The system can handle alternate SAW center frequencies and group delays simply by adjusting the VCO control and TDC delay control inputs. Because of frequency to voltage and phase to digital conversion, this topology does not require external frequency counter setups and is uniquely suitable for full monolithic integration of autonomous sensor systems and tags.

  13. The study on force, surface integrity, tool life and chip on laser assisted machining of inconel 718 using Nd:YAG laser source.

    Science.gov (United States)

    Venkatesan, K

    2017-07-01

    Inconel 718, a high-temperature alloy, is a promising material for high-performance aerospace gas turbine engines components. However, the machining of the alloy is difficult owing to immense shear strength, rapid work hardening rate during turning, and less thermal conductivity. Hence, like ceramics and composites, the machining of this alloy is considered as difficult-to-turn materials. Laser assisted turning method has become a promising solution in recent years to lessen cutting stress when materials that are considered difficult-to-turn, such as Inconel 718 is employed. This study investigated the influence of input variables of laser assisted machining on the machinability aspect of the Inconel 718. The comparison of machining characteristics has been carried out to analyze the process benefits with the variation of laser machining variables. The laser assisted machining variables are cutting speeds of 60-150 m/min, feed rates of 0.05-0.125 mm/rev with a laser power between 1200 W and 1300 W. The various output characteristics such as force, roughness, tool life and geometrical characteristic of chip are investigated and compared with conventional machining without application of laser power. From experimental results, at a laser power of 1200 W, laser assisted turning outperforms conventional machining by 2.10 times lessening in cutting force, 46% reduction in surface roughness as well as 66% improvement in tool life when compared that of conventional machining. Compared to conventional machining, with the application of laser, the cutting speed of carbide tool has increased to a cutting condition of 150 m/min, 0.125 mm/rev. Microstructural analysis shows that no damage of the subsurface of the workpiece.

  14. The study on force, surface integrity, tool life and chip on laser assisted machining of inconel 718 using Nd:YAG laser source

    Directory of Open Access Journals (Sweden)

    K. Venkatesan

    2017-07-01

    Full Text Available Inconel 718, a high-temperature alloy, is a promising material for high-performance aerospace gas turbine engines components. However, the machining of the alloy is difficult owing to immense shear strength, rapid work hardening rate during turning, and less thermal conductivity. Hence, like ceramics and composites, the machining of this alloy is considered as difficult-to-turn materials. Laser assisted turning method has become a promising solution in recent years to lessen cutting stress when materials that are considered difficult-to-turn, such as Inconel 718 is employed. This study investigated the influence of input variables of laser assisted machining on the machinability aspect of the Inconel 718. The comparison of machining characteristics has been carried out to analyze the process benefits with the variation of laser machining variables. The laser assisted machining variables are cutting speeds of 60–150 m/min, feed rates of 0.05–0.125 mm/rev with a laser power between 1200 W and 1300 W. The various output characteristics such as force, roughness, tool life and geometrical characteristic of chip are investigated and compared with conventional machining without application of laser power. From experimental results, at a laser power of 1200 W, laser assisted turning outperforms conventional machining by 2.10 times lessening in cutting force, 46% reduction in surface roughness as well as 66% improvement in tool life when compared that of conventional machining. Compared to conventional machining, with the application of laser, the cutting speed of carbide tool has increased to a cutting condition of 150 m/min, 0.125 mm/rev. Microstructural analysis shows that no damage of the subsurface of the workpiece.

  15. Study of surface integrity AISI 4140 as result of hard, dry and high speed machining using CBN

    Science.gov (United States)

    Ginting, B.; Sembiring, R. W.; Manurung, N.

    2017-09-01

    The concept of hard, dry and high speed machining can be combined, to produce high productivity, with lower production costs in manufacturing industry. Hard lathe process can be a solution to reduce production time. In lathe hard alloy steels reported problems relating to the integrity of such surface roughness, residual stress, the white layer and the surface integrity. AISI 4140 material is used for high reliable hydraulic system components. This material includes in cold work tool steel. Consideration election is because this material is able to be hardened up to 55 HRC. In this research, the experimental design using CCD model fit with three factors, each factor is composed of two levels, and six central point, experiments were conducted with 1 replications. The experimental design research using CCD model fit.

  16. QUALITY INFLUENCE OF SURFACE ON AIRCRAFT TAKE-OFF

    Directory of Open Access Journals (Sweden)

    2016-01-01

    Full Text Available The article considers quality impact influence of surface on aircraft take-off. It considers the IL-114 takeoff with all the operating engines. The goal of this research is to conduct calculating experiment to determine quality influence of surface on alteration of IL-114 takeoff characteristics during operation. Researches were carried out using the system of mathematical modeling of a flight dynamics. The main part of the system is a unit for calculating increments of aerodynam- ic coefficients caused with changing of technical condition of the surface of the airframe (roughness, waviness, available protruding elements on the airframe surface, etc. and residual deformation of the wing, fuselage, vertical and horizontal tail, as well as the difference between the rods symmetrically operating engines. In order to compute loss of rod and an increase in engine fuel consumption due to engine operation time during operation, an integral factor of thrust loss and increase in fuel consumption coefficient were introduced. Research proved that the individual characteristics of the aircraft, due to loss of engine power and increase in drag do not affect the assigned level of flight safety. The plane has a considera- ble reserve as for unsafe takeoff speed and the full gradient of climb, that ensures safety of operation.

  17. The Influence of the Relative Sliding on the Surface Quality

    Directory of Open Access Journals (Sweden)

    N. Diaconu

    2011-09-01

    Full Text Available This paper presents a study on the surface quality pointing out the influence of relative sliding on the topography parameters. Traditional roughness parameters as Ra and Rq, deal only with relative high of the asperities to the mean line and they give no information on shape, slope and asperities magnitude, on their appearance frequency on the profile length. The authors analysed a set of 3D parameters including the amplitude ones (Sa, Sku, Ssk and St and functional parameters as Svk, Sk and Spk as calculated with a dedicated soft from the bearing area. Tests were done on roller-roller tribotester lubricated with the grease grade UM185Li2EP (general purpose grease for rolling bearings, the temperature of the environment being kept at 80°C. There was studied the influence of relative sliding speed on the skewness and the kurtosis of the surface topography, but also on common parameters as Sa and St. Such a study may be used for selecting a suitable surface quality and to evaluate the surface topography degradation in time, after tests under severe conditions, very close to the actual ones.

  18. Ultra fast laser machined hydrophobic stainless ateel surface for drag reduction in laminar flows

    NARCIS (Netherlands)

    Jagdheesh, R.; Pathiraj, B.; Martin, A.G.; Del Cerro, D.A.; Lammertink, R.G.H.; Lohse, D.; Huis in 't Veld, A.J.; Römer, G.R.B.E.

    2010-01-01

    Hydrophobic surfaces have attracted much attention due to their potential in microfluidics, lab on chip devices and as functional surfaces for the automotive and aerospace industry. The combination of a dual scale roughness with an inherent low-surface-energy coating material is the pre-requisite fa

  19. Quality Assessment of Landsat Surface Reflectance Products Using MODIS Data

    Science.gov (United States)

    Feng, Min; Huang, Chengquan; Channan, Saurabh; Vermote, Eric; Masek, Jeffrey G.; Townshend, John R.

    2012-01-01

    Surface reflectance adjusted for atmospheric effects is a primary input for land cover change detection and for developing many higher level surface geophysical parameters. With the development of automated atmospheric correction algorithms, it is now feasible to produce large quantities of surface reflectance products using Landsat images. Validation of these products requires in situ measurements, which either do not exist or are difficult to obtain for most Landsat images. The surface reflectance products derived using data acquired by the Moderate Resolution Imaging Spectroradiometer (MODIS), however, have been validated more comprehensively. Because the MODIS on the Terra platform and the Landsat 7 are only half an hour apart following the same orbit, and each of the 6 Landsat spectral bands overlaps with a MODIS band, good agreements between MODIS and Landsat surface reflectance values can be considered indicators of the reliability of the Landsat products, while disagreements may suggest potential quality problems that need to be further investigated. Here we develop a system called Landsat-MODIS Consistency Checking System (LMCCS). This system automatically matches Landsat data with MODIS observations acquired on the same date over the same locations and uses them to calculate a set of agreement metrics. To maximize its portability, Java and open-source libraries were used in developing this system, and object-oriented programming (OOP) principles were followed to make it more flexible for future expansion. As a highly automated system designed to run as a stand-alone package or as a component of other Landsat data processing systems, this system can be used to assess the quality of essentially every Landsat surface reflectance image where spatially and temporally matching MODIS data are available. The effectiveness of this system was demonstrated using it to assess preliminary surface reflectance products derived using the Global Land Survey (GLS) Landsat

  20. Quality Control system for a hot-rolled metal surface

    Directory of Open Access Journals (Sweden)

    I. Mazur

    2016-07-01

    Full Text Available The modern ideas about of quality of products are based on the principle of the absolute satisfaction of requirements of recommendations of the buyer. A presence of surface defects of steel-smelting and rolling origin is peculiar to the production of hot-rolling mill. The automatic surface inspection system (ASIS includes two digital line video cameras for the filming of the upper and lower surfaces of the flat bar, block of illumination of the upper and lower surfaces of the flat bar, computer equipment. A system that secures 100 % control of the surface of rolled metal (of the upper and lower side detects automatically and classifies the sheet defects in the real time mode was mounted in the domestic practice in the first time in 2003 on hot rolling mill 2000 JSC «Novolipetsk Iron & Steel Corporation» (NISC. The whole assortment of the mill 2000 was divided for the five groups by the outward appearance of the surface. The works on the identification of defects of hot-rolled metal and widening of data base of knowledge of ASIS were continued after the carrying out of guarantee tests. More than 10 thousand images of defects were added to the data base during the year.

  1. Minimization of energy and surface roughness of the products machined by milling

    Science.gov (United States)

    Belloufi, A.; Abdelkrim, M.; Bouakba, M.; Rezgui, I.

    2017-08-01

    Metal cutting represents a large portion in the manufacturing industries, which makes this process the largest consumer of energy. Energy consumption is an indirect source of carbon footprint, we know that CO2 emissions come from the production of energy. Therefore high energy consumption requires a large production, which leads to high cost and a large amount of CO2 emissions. At this day, a lot of researches done on the Metal cutting, but the environmental problems of the processes are rarely discussed. The right selection of cutting parameters is an effective method to reduce energy consumption because of the direct relationship between energy consumption and cutting parameters in machining processes. Therefore, one of the objectives of this research is to propose an optimization strategy suitable for machining processes (milling) to achieve the optimum cutting conditions based on the criterion of the energy consumed during the milling. In this paper the problem of energy consumed in milling is solved by an optimization method chosen. The optimization is done according to the different requirements in the process of roughing and finishing under various technological constraints.

  2. Predictive Models for Different Roughness Parameters During Machining Process of Peek Composites Using Response Surface Methodology

    Directory of Open Access Journals (Sweden)

    Mata-Cabrera Francisco

    2013-10-01

    Full Text Available Polyetheretherketone (PEEK composite belongs to a group of high performance thermoplastic polymers and is widely used in structural components. To improve the mechanical and tribological properties, short fibers are added as reinforcement to the material. Due to its functional properties and potential applications, it’s impor- tant to investigate the machinability of non-reinforced PEEK (PEEK, PEEK rein- forced with 30% of carbon fibers (PEEK CF30, and reinforced PEEK with 30% glass fibers (PEEK GF30 to determine the optimal conditions for the manufacture of the parts. The present study establishes the relationship between the cutting con- ditions (cutting speed and feed rate and the roughness (Ra , Rt , Rq , Rp , by develop- ing second order mathematical models. The experiments were planned as per full factorial design of experiments and an analysis of variance has been performed to check the adequacy of the models. These state the adequacy of the derived models to obtain predictions for roughness parameters within ranges of parameters that have been investigated during the experiments. The experimental results show that the most influence of the cutting parameters is the feed rate, furthermore, proved that glass fiber reinforcements produce a worse machinability.

  3. The effects of different surface treatments on the shear bond strength of composite resin to machined titanium

    Science.gov (United States)

    Aljadi, Mohammad

    Purpose: The purpose of this study was to evaluate the shear bond strength between machined titanium and composite resin using different surface treatments. Materials and Methods: Titanium (Ti-6Al-4V) specimens were ground with 600 grit SiC paper and randomly divided into 6 groups (n=20/group). Group #1 (Control): samples were sandblasted with 110 microm Al2 O3 for 10 sec. Group #2 (Rocatec): samples were treated with the Rocatec system following the manufacturer's directions but the silanization step was eliminated. Group #3 (Silano Pen): samples were treated with the Silano Pen system. Group #4 (H2SO4 etched): samples were sandblasted with 110 microm Al2O3 for 10 sec and etched with 48% H2SO4 for 60 minutes at 60 oC. Group#5 (acid etching + Rocatec): samples received both treatments as described in Groups 4 and 2, respectively. Group #6 (acid etching + Silano Pen): samples received both treatments as described in Groups 4 and 3, respectively. Composite was bonded to the treated titanium surface, half of the specimens from each group (n=10/group) were subjected to thermocycling, and the samples were tested for shear bond strength in a universal testing machine. Representative samples from each group were evaluated with SEM. Results: Two-way ANOVA revealed that there were significant differences (p silanization step in the Rocatec system is a critical step and eliminating it may dramatically alter its effectiveness. 3) Combining two surface treatments may not always result in an additive effect. 4) Thermocycling significantly decreased the bond strength regardless of the surface treatment used.

  4. Surface roughness and cutting forces modeling for optimization of machining condition in finish hard turning of AISI 52100 steel

    Energy Technology Data Exchange (ETDEWEB)

    Azizi, Mohamed Walid; Belhadi, Salim; Yallese, Mohamed Athmane [Univ. of Guelma, Guelma (Algeria); Mabrouki, Tarek; Rigal, Jean Francois [Univ. of Lyon, Lyon (France)

    2012-12-15

    An experimental investigation was conducted to analyze the effect of cutting parameters (cutting speed, feed rate and depth of cut) and workpiece hardness on surface roughness and cutting force components. The finish hard turning of AISI 52100 steel with coated Al2O3 + TiC mixed ceramic cutting tools was studied. The planning of experiment were based on Taguchi's L27 orthogonal array. The response table and analysis of variance (ANOVA) have allowed to check the validity of linear regression model and to determine the significant parameters affecting the surface roughness and cutting forces. The statistical analysis reveals that the feed rate, workpiece hardness and cutting speed have significant effects in reducing the surface roughness; whereas the depth of cut, workpiece hardness and feed rate are observed to have a statistically significant impact on the cutting force components than the cutting speed. Consequently, empirical models were developed to correlate the cutting parameters and workpiece hardness with surface roughness and cutting forces. The optimum machining conditions to produce the lowest surface roughness with minimal cutting force components under these experimental conditions were searched using desirability function approach for multiple response factors optimization. Finally, confirmation experiments were performed to verify the pertinence of the developed empirical models.

  5. Machine-Learning Based Channel Quality and Stability Estimation for Stream-Based Multichannel Wireless Sensor Networks

    Science.gov (United States)

    Rehan, Waqas; Fischer, Stefan; Rehan, Maaz

    2016-01-01

    Wireless sensor networks (WSNs) have become more and more diversified and are today able to also support high data rate applications, such as multimedia. In this case, per-packet channel handshaking/switching may result in inducing additional overheads, such as energy consumption, delays and, therefore, data loss. One of the solutions is to perform stream-based channel allocation where channel handshaking is performed once before transmitting the whole data stream. Deciding stream-based channel allocation is more critical in case of multichannel WSNs where channels of different quality/stability are available and the wish for high performance requires sensor nodes to switch to the best among the available channels. In this work, we will focus on devising mechanisms that perform channel quality/stability estimation in order to improve the accommodation of stream-based communication in multichannel wireless sensor networks. For performing channel quality assessment, we have formulated a composite metric, which we call channel rank measurement (CRM), that can demarcate channels into good, intermediate and bad quality on the basis of the standard deviation of the received signal strength indicator (RSSI) and the average of the link quality indicator (LQI) of the received packets. CRM is then used to generate a data set for training a supervised machine learning-based algorithm (which we call Normal Equation based Channel quality prediction (NEC) algorithm) in such a way that it may perform instantaneous channel rank estimation of any channel. Subsequently, two robust extensions of the NEC algorithm are proposed (which we call Normal Equation based Weighted Moving Average Channel quality prediction (NEWMAC) algorithm and Normal Equation based Aggregate Maturity Criteria with Beta Tracking based Channel weight prediction (NEAMCBTC) algorithm), that can perform channel quality estimation on the basis of both current and past values of channel rank estimation. In the end

  6. Machine-Learning Based Channel Quality and Stability Estimation for Stream-Based Multichannel Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Waqas Rehan

    2016-09-01

    Full Text Available Wireless sensor networks (WSNs have become more and more diversified and are today able to also support high data rate applications, such as multimedia. In this case, per-packet channel handshaking/switching may result in inducing additional overheads, such as energy consumption, delays and, therefore, data loss. One of the solutions is to perform stream-based channel allocation where channel handshaking is performed once before transmitting the whole data stream. Deciding stream-based channel allocation is more critical in case of multichannel WSNs where channels of different quality/stability are available and the wish for high performance requires sensor nodes to switch to the best among the available channels. In this work, we will focus on devising mechanisms that perform channel quality/stability estimation in order to improve the accommodation of stream-based communication in multichannel wireless sensor networks. For performing channel quality assessment, we have formulated a composite metric, which we call channel rank measurement (CRM, that can demarcate channels into good, intermediate and bad quality on the basis of the standard deviation of the received signal strength indicator (RSSI and the average of the link quality indicator (LQI of the received packets. CRM is then used to generate a data set for training a supervised machine learning-based algorithm (which we call Normal Equation based Channel quality prediction (NEC algorithm in such a way that it may perform instantaneous channel rank estimation of any channel. Subsequently, two robust extensions of the NEC algorithm are proposed (which we call Normal Equation based Weighted Moving Average Channel quality prediction (NEWMAC algorithm and Normal Equation based Aggregate Maturity Criteria with Beta Tracking based Channel weight prediction (NEAMCBTC algorithm, that can perform channel quality estimation on the basis of both current and past values of channel rank estimation

  7. Machine-Learning Based Channel Quality and Stability Estimation for Stream-Based Multichannel Wireless Sensor Networks.

    Science.gov (United States)

    Rehan, Waqas; Fischer, Stefan; Rehan, Maaz

    2016-09-12

    Wireless sensor networks (WSNs) have become more and more diversified and are today able to also support high data rate applications, such as multimedia. In this case, per-packet channel handshaking/switching may result in inducing additional overheads, such as energy consumption, delays and, therefore, data loss. One of the solutions is to perform stream-based channel allocation where channel handshaking is performed once before transmitting the whole data stream. Deciding stream-based channel allocation is more critical in case of multichannel WSNs where channels of different quality/stability are available and the wish for high performance requires sensor nodes to switch to the best among the available channels. In this work, we will focus on devising mechanisms that perform channel quality/stability estimation in order to improve the accommodation of stream-based communication in multichannel wireless sensor networks. For performing channel quality assessment, we have formulated a composite metric, which we call channel rank measurement (CRM), that can demarcate channels into good, intermediate and bad quality on the basis of the standard deviation of the received signal strength indicator (RSSI) and the average of the link quality indicator (LQI) of the received packets. CRM is then used to generate a data set for training a supervised machine learning-based algorithm (which we call Normal Equation based Channel quality prediction (NEC) algorithm) in such a way that it may perform instantaneous channel rank estimation of any channel. Subsequently, two robust extensions of the NEC algorithm are proposed (which we call Normal Equation based Weighted Moving Average Channel quality prediction (NEWMAC) algorithm and Normal Equation based Aggregate Maturity Criteria with Beta Tracking based Channel weight prediction (NEAMCBTC) algorithm), that can perform channel quality estimation on the basis of both current and past values of channel rank estimation. In the end

  8. The Evaluation Methods of Decorative Concrete Horizontal Surfaces Quality

    Directory of Open Access Journals (Sweden)

    Albertas KLOVAS

    2013-09-01

    Full Text Available The main aim of this article was to determine blemishes of concrete surfaces and divide those surfaces according to following methods provided by two documents and by authors proposed image scanning method - “ImageJ”. The first method was CIB Report No. 24 “Tolerances on blemishes of concrete”. This method enables to evaluate concrete surfaces according to their visual appearance by using certain reference cards. The second method was GOST 13015.0-83. This method enables to evaluate the concrete surfaces according to their biggest dimension of the blemishes. The third, authors proposed, method was “ImageJ”. Latter method is based on the free source computer program. It helps to establish the quantity and the dimensions of the blemishes in the desired scale. Authors suggested to imply a ration between blemishes area and the all specimen’s area as a factor for evaluation of concrete surface quality. Three different concrete compositions were made: BA1, BA7 and BA8. Also, five different formworks were used: wood impregnated with polymeric oil [WPO], wood covered with rubber [WCR], sawn timber [ST], metal [M] and plastic [P] formworks. Following parameters of the obtained results were calculated: mean value, dispersion, standard deviation and the coefficient of variation. Also maximum and minimum values of experimental results are given. Intervals of the experimental results are provided for each specimen with the biggest possibility. DOI: http://dx.doi.org/10.5755/j01.ms.19.3.2006

  9. Structure-based sampling and self-correcting machine learning for accurate calculations of potential energy surfaces and vibrational levels

    Science.gov (United States)

    Dral, Pavlo O.; Owens, Alec; Yurchenko, Sergei N.; Thiel, Walter

    2017-06-01

    We present an efficient approach for generating highly accurate molecular potential energy surfaces (PESs) using self-correcting, kernel ridge regression (KRR) based machine learning (ML). We introduce structure-based sampling to automatically assign nuclear configurations from a pre-defined grid to the training and prediction sets, respectively. Accurate high-level ab initio energies are required only for the points in the training set, while the energies for the remaining points are provided by the ML model with negligible computational cost. The proposed sampling procedure is shown to be superior to random sampling and also eliminates the need for training several ML models. Self-correcting machine learning has been implemented such that each additional layer corrects errors from the previous layer. The performance of our approach is demonstrated in a case study on a published high-level ab initio PES of methyl chloride with 44 819 points. The ML model is trained on sets of different sizes and then used to predict the energies for tens of thousands of nuclear configurations within seconds. The resulting datasets are utilized in variational calculations of the vibrational energy levels of CH3Cl. By using both structure-based sampling and self-correction, the size of the training set can be kept small (e.g., 10% of the points) without any significant loss of accuracy. In ab initio rovibrational spectroscopy, it is thus possible to reduce the number of computationally costly electronic structure calculations through structure-based sampling and self-correcting KRR-based machine learning by up to 90%.

  10. ASSESSMENT OF SURFACE WATER QUALITY IN AN ARSENIC CONTAMINATED VILLAGE

    Directory of Open Access Journals (Sweden)

    Kumud C. Saikia

    2012-01-01

    Full Text Available Arsenic contamination of ground water has occurred in various parts of the world, becoming a menace in the Ganga-Meghna-Brahmaputra basin (West Bengal and Assam in India and Bangladesh. Recently arsenic has been detected in Cachar and Karimganj districts of barak valley, Assam, bordering Bangladesh. In this area coli form contamination comprises the major constraint towards utilization of its otherwise ample surface water resources. The local water management exploited ground water sources using a centralized piped water delivery scheme without taking into account the geologically arsenic-prone nature of the sediments and aquifers in this area. Thus surface water was the suggestive alternative for drinking water in this area. The present study investigated surface water quality and availability in a village of Karimganj district, Assam, India contaminated with arsenic for identifying the potential problems of surface water quality maintenance so that with effective management safe drinking water could be provided. The study revealed that the area was rich in freshwater ecosystems which had all physico-chemical variables such as water temperature, pH, DO, total alkalinity, free CO2, heavy metals like lead, chromium and cadmium within WHO standards. In contrast, coli form bacteria count was found far beyond permissible limit in all the sources. Around 60% people of the village preferred ground water for drinking and only 6% were aware of arsenic related problems. The problem of bacterial contamination could be controlled by implementing some ameliorative measures so that people can safely use surface water. Inhabitants of the two districts should be given proper education regarding arsenic contamination and associated health risk. Effluents should be treated to acceptable levels and standards before discharging them into natural streams.

  11. Modification of three dimensional topography of the machined KDP crystal surface using wavelet analysis method

    Science.gov (United States)

    Wang, H. X.; Zong, W. J.; Sun, T.; Liu, Q.

    2010-06-01

    The wavelet analysis method has been extensively employed to analyze the surface structures and evaluate the surface roughness. In this work, however, the wavelet analysis method was introduced to decompose and reconstruct the sampled surface profile signals in the cutting direction that achieved by SPDT (single point diamond turning) operation, and the surface profile signals in tool feeding direction were reconstructed with the approximate harmonic functions directly. And moreover, the orthogonal design method, i.e. the combination design of general rotary method, was resorted to model the variations of the independent frequency and amplitude of different simulated harmonic signals in the cutting and tool feeding directions. As expected resultantly, a novel 3D surface topography modeling solution was established, which aims to predict and modify the finished KDP (potassium dihydrogen phosphate or KH 2PO 4) crystal surfaces. The validation tests were carried out finally under different cutting conditions, and the collected average surface roughness in any case was compared with the corresponding value as predicted. The results indicated the experimental data were well consistent with the predictions, and only an average relative error of 11.4% occurred in predicting the average surface roughness.

  12. Accelerating the search for global minima on potential energy surfaces using machine learning

    Science.gov (United States)

    Carr, S. F.; Garnett, R.; Lo, C. S.

    2016-10-01

    Controlling molecule-surface interactions is key for chemical applications ranging from catalysis to gas sensing. We present a framework for accelerating the search for the global minimum on potential surfaces, corresponding to stable adsorbate-surface structures. We present a technique using Bayesian inference that enables us to predict converged density functional theory potential energies with fewer self-consistent field iterations. We then discuss how this technique fits in with the Bayesian Active Site Calculator, which applies Bayesian optimization to the problem. We demonstrate the performance of our framework using a hematite (Fe2O3) surface and present the adsorption sites found by our global optimization method for various simple hydrocarbons on the rutile TiO2 (110) surface.

  13. Compare and Selection of Sloped Surfaces Machining Methods in MasterCAM9.0%MasterCAM9.0中斜面加工方案的比较与选择

    Institute of Scientific and Technical Information of China (English)

    何伟

    2014-01-01

    Taking sloped surfaces feature in actual processing as research object,all kinds machining methods were compared and studied by using MasterCAM9.0, by the research results, how to choose the proper machining methods is known on the premise of assuring quality and efficiency of processing.%本文以实际生产加工过程中的斜面特征为研究对象,通过MasterCAM9.0中各种斜面加工方法的比较研究,论述了在保证加工质量和效率的前提下,如何选择适合的加工方法。

  14. 用反圆环面刀加工变曲率过渡曲面原理%Principle of machining variant with counter curvature blending surfaces torus cutter

    Institute of Scientific and Technical Information of China (English)

    黄魏; 陈志同; 陈五一; 贺英

    2012-01-01

    基于宽行加工理论和广域曲率吻合原则,提出一种利用圆环面内侧作为刀具工作面的反圆环面刀具宽行加工叶片进排气边的新方法.该方法通过优化刀具摆角使具有定母圆半径刀具工作面的包络面充分逼近叶片进排气边曲面,从而使刀具能在给定的精度范围内以最大行宽和最少刀轨行数加工出进排气边.最后,以某型号发动机叶片的进气边为例进行了加工实验.结果表明该方法能够大幅提高进排气边的加工质量,且反圆环面刀的加工行宽比球头刀提高了5倍.%Based on the stripe-width-maximization machining theory and the principle of global curvature fitting, a novel counter torus cutter, which uses the inner surface of torus as the cutting edge, was proposed to machine the leading and trailing edge of a turbine blade. Through optimizing the raw angle of the counter torus cutter with a circular generatrix of given radius, the envelope surface of the tool can closely approximate the leading and trailing edge surface of the turbine blade with variant curvature, which can be machined by maxi- mizing the machining strip width and minimizing the number of tool paths under a given tolerance. An experi- ment to machine the leading and trailing edge of an aero-engine turbine blade was carried out. Results illus- trate that the proposed method could greatly improve the machining quality of the leading and trailing edge, and the machining strip-width using a counter torus cutter is 5 times larger than that using a ball nose cutter.

  15. Managing Quality, Identity and Adversaries in Public Discourse with Machine Learning

    Science.gov (United States)

    Brennan, Michael

    2012-01-01

    Automation can mitigate issues when scaling and managing quality and identity in public discourse on the web. Discourse needs to be curated and filtered. Anonymous speech has to be supported while handling adversaries. Reliance on human curators or analysts does not scale and content can be missed. These scaling and management issues include the…

  16. Wastewater quality monitoring system using sensor fusion and machine learning techniques.

    Science.gov (United States)

    Qin, Xusong; Gao, Furong; Chen, Guohua

    2012-03-15

    A multi-sensor water quality monitoring system incorporating an UV/Vis spectrometer and a turbidimeter was used to monitor the Chemical Oxygen Demand (COD), Total Suspended Solids (TSS) and Oil & Grease (O&G) concentrations of the effluents from the Chinese restaurant on campus and an electrocoagulation-electroflotation (EC-EF) pilot plant. In order to handle the noise and information unbalance in the fused UV/Vis spectra and turbidity measurements during the calibration model building, an improved boosting method, Boosting-Iterative Predictor Weighting-Partial Least Squares (Boosting-IPW-PLS), was developed in the present study. The Boosting-IPW-PLS method incorporates IPW into boosting scheme to suppress the quality-irrelevant variables by assigning small weights, and builds up the models for the wastewater quality predictions based on the weighted variables. The monitoring system was tested in the field with satisfactory results, underlying the potential of this technique for the online monitoring of water quality. Copyright © 2011 Elsevier Ltd. All rights reserved.

  17. Managing Quality, Identity and Adversaries in Public Discourse with Machine Learning

    Science.gov (United States)

    Brennan, Michael

    2012-01-01

    Automation can mitigate issues when scaling and managing quality and identity in public discourse on the web. Discourse needs to be curated and filtered. Anonymous speech has to be supported while handling adversaries. Reliance on human curators or analysts does not scale and content can be missed. These scaling and management issues include the…

  18. Recent Advances on Permanent Magnet Machines

    Institute of Scientific and Technical Information of China (English)

    诸自强

    2012-01-01

    This paper overviews advances on permanent magnet(PM) brushless machines over last 30 years,with particular reference to new and novel machine topologies.These include current states and trends for surface-mounted and interior PM machines,electrically and mechanically adjusted variable flux PM machines including memory machine,hybrid PM machines which uniquely integrate PM technology into induction machines,switched and synchronous reluctance machines and wound field machines,Halbach PM machines,dual-rotor PM machines,and magnetically geared PM machines,etc.The paper highlights their features and applications to various market sectors.

  19. Multi-objective parametric optimization of powder mixed electro-discharge machining using response surface methodology and non-dominated sorting genetic algorithm

    Indian Academy of Sciences (India)

    Soumyakant Padhee; Niharranjan Nayak; S K Panda; P R Dhal; S S Mahapatra

    2012-04-01

    Powder mixed electro-discharge machining (EDM) is being widely used in modern metal working industry for producing complex cavities in dies and moulds which are otherwise difficult to create by conventional machining route. It has been experimentally demonstrated that the presence of suspended particle in dielectric fluid significantly increases the surface finish and machining efficiency of EDM process. Concentration of powder (silicon) in the dielectric fluid, pulse on time, duty cycle, and peak current are taken as independent variables on which the machining performance was analysed in terms of material removal rate (MRR) and surface roughness (SR). Experiments have been conducted on an EZNC fuzzy logic Die Sinking EDM machine manufactured by Electronica Machine Tools Ltd. India. A copper electrode having diameter of 25 mm is used to cut EN 31 steel for one hour in each trial. Response surface methodology (RSM) is adopted to study the effect of independent variables on responses and develop predictive models. It is desired to obtain optimal parameter setting that aims at decreasing surface roughness along with larger material removal rate. Since the responses are conflicting in nature, it is difficult to obtain a single combination of cutting parameters satisfying both the objectives in any one solution. Therefore, it is essential to explore the optimization landscape to generate the set of dominant solutions. Non-sorted genetic algorithm (NSGA) has been adopted to optimize the responses such that a set of mutually dominant solutions are found over a wide range of machining parameters.

  20. A Web Tool for Generating High Quality Machine-readable Biological Pathways.

    Science.gov (United States)

    Ramirez-Gaona, Miguel; Marcu, Ana; Pon, Allison; Grant, Jason; Wu, Anthony; Wishart, David S

    2017-02-08

    PathWhiz is a web server built to facilitate the creation of colorful, interactive, visually pleasing pathway diagrams that are rich in biological information. The pathways generated by this online application are machine-readable and fully compatible with essentially all web-browsers and computer operating systems. It uses a specially developed, web-enabled pathway drawing interface that permits the selection and placement of different combinations of pre-drawn biological or biochemical entities to depict reactions, interactions, transport processes and binding events. This palette of entities consists of chemical compounds, proteins, nucleic acids, cellular membranes, subcellular structures, tissues, and organs. All of the visual elements in it can be interactively adjusted and customized. Furthermore, because this tool is a web server, all pathways and pathway elements are publicly accessible. This kind of pathway "crowd sourcing" means that PathWhiz already contains a large and rapidly growing collection of previously drawn pathways and pathway elements. Here we describe a protocol for the quick and easy creation of new pathways and the alteration of existing pathways. To further facilitate pathway editing and creation, the tool contains replication and propagation functions. The replication function allows existing pathways to be used as templates to create or edit new pathways. The propagation function allows one to take an existing pathway and automatically propagate it across different species. Pathways created with this tool can be "re-styled" into different formats (KEGG-like or text-book like), colored with different backgrounds, exported to BioPAX, SBGN-ML, SBML, or PWML data exchange formats, and downloaded as PNG or SVG images. The pathways can easily be incorporated into online databases, integrated into presentations, posters or publications, or used exclusively for online visualization and exploration. This protocol has been successfully applied to

  1. Use of near-infrared spectroscopy and least-squares support vector machine to determine quality change of tomato juice

    Institute of Scientific and Technical Information of China (English)

    Li-juan XIE; Yi-bin YING

    2009-01-01

    Near-infrared (NIR) transmittance spectroscopy combined with least-squares support vector machine (LS-SVM) was investigated to study the quality change of tomato juice during the storage. A total of 100 tomato juice samples were used. The spectrum of each tomato juice was collected twice: the first measurement was taken when the tomato juice was fresh and had not undergone any changes, and the second measurement was taken after a month. Principal component analysis (PCA) was used to examine a potential capability of separating juice before and after the storage. The soluble solid content (SSC) and pH of the juice samples were determined. The results show that changes in certain compounds between tomato juice before and after the storage period were obvious. An excellent precision was achieved by LS-SVM model compared with discriminant partial least-squares (DPLS), soft independent modeling of class analogy (SIMCA), and discriminant analysis (DA) models, with 100% of a total accuracy. It can be found that N1R spectroscopy coupled with LS-SVM, DPLS, SIMCA, and DA can be used to control the quality change of tomato juice during the storage.

  2. 麻醉机质量控制检测与结果的分析%Analysis of quality control testing and results of the anesthesia machine

    Institute of Scientific and Technical Information of China (English)

    黄韬; 崔骊; 李向东; 云庆辉

    2013-01-01

    目的:通过对麻醉机的质量控制检测,分析造成麻醉机不合格的主要原因,并采取相应措施确保麻醉机的安全使用。方法:使用美国VT-PLUS-HF气流分析仪对医院麻醉机定期检测,并利用检测结果对麻醉机的质量状况进行统计分析,评估不合格因素。结果:通过对医院麻醉机定期检测和分析检测结果,采取相应的方法消除了多台麻醉机的安全隐患,保障其使用安全。结论:麻醉机的质量控制检测工作是医疗安全的重要组成部分,通过检测能够及时发现和消除麻醉机的安全隐患,确保患者的生命安全。%Objective:Though the result study of quality control testing of anesthesia machine by 4 yesrs, the factors to anesthesia machine failure is investigated, and the proposal of improving the quality of the equipment testing standards is given. Methods:Statistical analysis the quality of the anesthesia machines using the VT-PLUS-HF gas analyzers with U.S.FLUKE Corporation is used, the test results can be to assess the quality of the anesthesia machine fail factors. Results: Through regular detection, not only can anesthesia machine potential risk be eliminated but also quality safety of clinical use will be safeguarded. Conclusion: Quality control detection to anesthesia machine is an important component of medical safety. It concluded that detect the anesthesia machine security risks by quality controls, ensure the life safety of patients.

  3. Final Report on Control Algorithm to Improve the Partial-Load Efficiency of Surface PM Machines with Fractional-Slot Concentrated Windings

    Energy Technology Data Exchange (ETDEWEB)

    McKeever, John W [ORNL; Reddy, Patel [University of Wisconsin; Jahns, Thomas M [ORNL

    2007-05-01

    Surface permanent magnet (SPM) synchronous machines using fractional-slot concentrated windings are being investigated as candidates for high-performance traction machines for automotive electric propulsion systems. It has been shown analytically and experimentally that such designs can achieve very wide constant-power speed ratios (CPSR) [1,2]. This work has shown that machines of this type are capable of achieving very low cogging torque amplitudes as well as significantly increasing the machine power density [3-5] compared to SPM machines using conventional distributed windings. High efficiency can be achieved in this class of SPM machine by making special efforts to suppress the eddy-current losses in the magnets [6-8], accompanied by efforts to minimize the iron losses in the rotor and stator cores. Considerable attention has traditionally been devoted to maximizing the full-load efficiency of traction machines at their rated operating points and along their maximum-power vs. speed envelopes for higher speeds [9,10]. For example, on-line control approaches have been presented for maximizing the full-load efficiency of PM synchronous machines, including the use of negative d-axis stator current to reduce the core losses [11,12]. However, another important performance specification for electric traction applications is the machine's efficiency at partial loads. Partial-load efficiency is particularly important if the target traction application requires long periods of cruising operation at light loads that are significantly lower than the maximum drive capabilities. While the design of the machine itself is clearly important, investigation has shown that this is a case where the choice of the control algorithm plays a critical role in determining the maximum partial-load efficiency that the machine actually achieves in the traction drive system. There is no evidence that this important topic has been addressed for this type of SPM machine by any other

  4. Estimation of algal colonization growth on mortar surface using a hybridization of machine learning and metaheuristic optimization

    Indian Academy of Sciences (India)

    THU-HIEN TRAN; NHAT-DUC HOANG

    2017-06-01

    Estimation of the algal colonization growth on fac¸ade structure can provide useful information for the task of building maintenance. This research proposes a machine learning method based on the least squares support vector regression (LS-SVR) for modelling the growth time of the green alga Klebsormidium flaccidum on mortar surfaces. Furthermore, to identify an appropriate set of the LS-SVR hyper-parameters, the flower pollination algorithm (FPA) is employed as an optimization technique. The characteristics of the mortar samples, including surface roughness, porosity, surface pH, carbonated condition and type of cement, are employed as input factors for the analysing process. This study relies on a dataset that records 539 laboratory experiments to establish a hybrid model of the LS-SVR and the FPA. The cross-validation process reveals that the proposed method can successfully capture the functional relationship between the algal colonization growth and its influencing factors with a satisfactory outcome (the coefficient of determination R 2 = 0.94 and the root meansquare error RMSE = 4.55). These facts demonstrate that the hybrid model is a promising tool for assisting the decision-making process in building maintenance planning

  5. Landsat surface reflectance quality assurance extraction (version 1.7)

    Science.gov (United States)

    Jones, J.W.; Starbuck, M.J.; Jenkerson, C.B.

    2013-01-01

    The U.S. Geological Survey (USGS) Land Remote Sensing Program is developing an operational capability to produce Climate Data Records (CDRs) and Essential Climate Variables (ECVs) from the Landsat Archive to support a wide variety of science and resource management activities from regional to global scale. The USGS Earth Resources Observation and Science (EROS) Center is charged with prototyping systems and software to generate these high-level data products. Various USGS Geographic Science Centers are charged with particular ECV algorithm development and (or) selection as well as the evaluation and application demonstration of various USGS CDRs and ECVs. Because it is a foundation for many other ECVs, the first CDR in development is the Landsat Surface Reflectance Product (LSRP). The LSRP incorporates data quality information in a bit-packed structure that is not readily accessible without postprocessing services performed by the user. This document describes two general methods of LSRP quality-data extraction for use in image processing systems. Helpful hints for the installation and use of software originally developed for manipulation of Hierarchical Data Format (HDF) produced through the National Aeronautics and Space Administration (NASA) Earth Observing System are first provided for users who wish to extract quality data into separate HDF files. Next, steps follow to incorporate these extracted data into an image processing system. Finally, an alternative example is illustrated in which the data are extracted within a particular image processing system.

  6. 复杂曲面的数控加工误差分析%Error Analysis of the Complex Surface NC Machining

    Institute of Scientific and Technical Information of China (English)

    王振; 韩祥凤

    2011-01-01

    针对复杂曲面的多轴数控加工,应用数学知识建模,从理论上分析了平底铣刀刀具加工复杂曲面时的误差,得出了影响数控加工精度的主要因素并提出了误差补偿方法,为控制多轴数控加工的误兰提供了理论依据与补偿算法,对高精度复杂曲面的数控加工具有借鉴意义.%Complex surfaces are normally manufactured with multi-axis NC machining tools, This paper has applied the mathematical modeling and analyzed the occurring error when the flat milling cutter machining the complex surface in theory. The author found the main reasons affecting the accuracy of NC machining, proposed the method to compensate the error and provided a theoretical basis and the compensation algorithm for the control of multi-axis NC machining, which has the enlightenment to NC machining of the complex curve surface.

  7. PERFORMANCE OF COATED CUTTING TOOLS IN MACHINING HARDENED STEEL

    Directory of Open Access Journals (Sweden)

    K.Subramanyam,

    2010-10-01

    Full Text Available This paper deals with the study of the performance of coated tools in machining hardening steel under dry conditions. This paper involves of machining AISI 4340 hardened steel using coated carbide tools is studied using full factorial experiments. Many parameters influence the quality of the products in hard turning process. The objective of this study is on the effect of the cutting conditions such as cutting velocity, feed, and depth of cut on the surface finish in machining AISI 4340 hardened steel. Machining of hardened steels has become an important manufacturing process, particularly in the automotive and bearing industries.

  8. Near-Surface Crevasse Detection in Ice Sheets using Feature-Based Machine Learning

    Science.gov (United States)

    Ray, L.; Walker, B.; Lever, J.; Arcone, S. A.

    2015-12-01

    In 2014, a team of Dartmouth, CRREL, and University of Maine researchers conducted the first of three annual ground-penetrating radar surveys of the McMurdo Shear Zone using robot-towed instruments. This survey provides over 100 transects of a 5.7 km x 5.0 km grid spanning the width of the shear zone at spacing of approximately 50 m. Transect direction was orthogonal to ice flow. Additionally, a dense 200 m x 200 m grid was surveyed at 10 m spacing in both the N-S and W-E directions. Radar settings provided 20 traces/sec, which combined with an average robot speed of 1.52 m/s, provides a trace every 7.6 cm. The robot towed two antenna units at 400 MHz and 200 MHz center frequencies, with the former penetrating to approximately 19 m. We establish boundaries for the shear zone over the region surveyed using the 400 MHz antenna data, and we geo-locate crevasses using feature-based machine learning classification of GPR traces into one of three classes - 1) firn, 2) distinct crevasses, and 3) less distinct or deeper features originating within the 19 m penetration depth. Distinct crevasses feature wide, hyperbolic reflections with strike angles of 35-40° to transect direction and clear voids. Less distinct or deeper features range from broad diffraction patterns with no clear void to overlapping diffractions extending tens of meters in width with or without a clear void. The classification is derived from statistical features of unprocessed traces and thus provides a computationally efficient means for eventual real-time classification of GPR traces. Feature-based classification is shown to be insensitive to artifacts related to rolling or pitching motion of the instrument sled and also provides a means of assessing crevasse width and depth. In subsequent years, we will use feature-based classification to estimate ice flow and evolution of individual crevasses.

  9. Using Satellite Aerosol Retrievals to Monitor Surface Particulate Air Quality

    Science.gov (United States)

    Levy, Robert C.; Remer, Lorraine A.; Kahn, Ralph A.; Chu, D. Allen; Mattoo, Shana; Holben, Brent N.; Schafer, Joel S.

    2011-01-01

    The MODIS and MISR aerosol products were designed nearly two decades ago for the purpose of climate applications. Since launch of Terra in 1999, these two sensors have provided global, quantitative information about column-integrated aerosol properties, including aerosol optical depth (AOD) and relative aerosol type parameters (such as Angstrom exponent). Although primarily designed for climate, the air quality (AQ) community quickly recognized that passive satellite products could be used for particulate air quality monitoring and forecasting. However, AOD and particulate matter (PM) concentrations have different units, and represent aerosol conditions in different layers of the atmosphere. Also, due to low visible contrast over brighter surface conditions, satellite-derived aerosol retrievals tend to have larger uncertainty in urban or populated regions. Nonetheless, the AQ community has made significant progress in relating column-integrated AOD at ambient relative humidity (RH) to surface PM concentrations at dried RH. Knowledge of aerosol optical and microphysical properties, ambient meteorological conditions, and especially vertical profile, are critical for physically relating AOD and PM. To make urban-scale maps of PM, we also must account for spatial variability. Since surface PM may vary on a finer spatial scale than the resolution of standard MODIS (10 km) and MISR (17km) products, we test higher-resolution versions of MODIS (3km) and MISR (1km research mode) retrievals. The recent (July 2011) DISCOVER-AQ campaign in the mid-Atlantic offers a comprehensive network of sun photometers (DRAGON) and other data that we use for validating the higher resolution satellite data. In the future, we expect that the wealth of aircraft and ground-based measurements, collected during DISCOVER-AQ, will help us quantitatively link remote sensed and ground-based measurements in the urban region.

  10. Effect of tube-electrode inner diameter on electrochemical discharge machining of nickel-based superalloy

    Institute of Scientific and Technical Information of China (English)

    Zhang Yan; Xu Zhengyang; Xing Jun; Zhu Di

    2016-01-01

    Nickel-based superalloys are widely employed in modern aircraft engines because of their excellent material characteristics, particularly in the fabrication of film cooling holes. How-ever, the high machining requirement of a large number of film cooling holes can be extremely chal-lenging. The hybrid machining technique of tube electrode high-speed electrochemical discharge drilling (TEHECDD) has been considered as a promising method for the production of film cooling holes. Compared with any single machining process, this hybrid technique requires the removal of more complex machining by-products, including debris produced in the electrical discharge machin-ing process and hydroxide and bubbles generated in the electrochemical machining process. These by-products significantly affect the machining efficiency and surface quality of the machined prod-ucts. In this study, tube electrodes in different inner diameters are designed and fabricated, and the effects of inner diameter on the machining efficiency and surface quality of TEHECDD are inves-tigated. The results show that larger inner diameters could effectively improve the flushing condi-tion and facilitate the removal of machining by-products. Therefore, higher material removal efficiency, surface quality, and electrode wear rate could be achieved by increasing the inner diam-eter of the tube electrode.

  11. Investigations of influence of vibration smoothing conditions of geometrical structure on machined surfaces

    Science.gov (United States)

    Bańkowski, D.; Spadło, S.

    2017-02-01

    The paper presents influence of the type of abrasive media on the operating parameters of the surface of components made of composite ceramic-glass, coated with a layer of antiferromagnetic. The research presents the possibilities offered by the use of resin bonded media with different intensities abrasive, understood as different content of abrasive grains. There were used Rollwasch smoothing media PB series – resin plastic media. Media were cone-shaped, with different abrasive properties (10%, 50% and 85%). The process was carried out by using chemical compounds - liquid supportive ME series L100 A22 / NF. Attention has also been given to the relation between the properties of abrasive media and surfaces that can be obtained after polishing with porcelain media and deburring with resin bonded media. As the output surface used the disc of hard drive. Then, to analysis of the possibility various kinds of abrasive media in vibratory finishing the analysis of surface texture with an optical profilometer Talysurf CCI Lite - Taylor Hobson were done. As a result of the effects polishing and deburring using vibratory finishing were compared.

  12. Multiple-Objective Particle Swarm Optimization for Multi-Head Beam-Type Surface Mounting Machines

    NARCIS (Netherlands)

    Torabi, S.A.; Hamedi, M.; Ashayeri, J.

    2010-01-01

    The growing demand for electronic devices has made the manufacturing of printed circuit boards (PCBs) a promising industry over the last decades. As the demand for printed circuit boards increases, the industry becomes more dependent on highly automated assembly processes using Surface Mounting Devi

  13. Step-height measurements on sand surfaces: A comparison between optical scanner and coordinate measuring machine

    DEFF Research Database (Denmark)

    Mohaghegh, Kamran; Yazdanbakhsh, Seyed Alireza; Tiedje, Niels Skat

    2016-01-01

    the same routine to touch the different positions on the polygonised mesh. Each measurement was repeated 5 times. The results of step height measurements on sand surfaces showed a maximum error of ± 12 µm for CMM, while scanner shows only ± 4 µm. Generally speaking, optical step height values were measured...

  14. Statistical robustness of machine-learning estimates for characterizing a groundwater-surface water system, Southland, New Zealand

    Science.gov (United States)

    Friedel, M. J.; Daughney, C.

    2016-12-01

    The development of a successful surface-groundwater management strategy depends on the quality of data provided for analysis. This study evaluates the statistical robustness when using a modified self-organizing map (MSOM) technique to estimate missing values for three hypersurface models: synoptic groundwater-surface water hydrochemistry, time-series of groundwater-surface water hydrochemistry, and mixed-survey (combination of groundwater-surface water hydrochemistry and lithologies) hydrostratigraphic unit data. These models of increasing complexity are developed and validated based on observations from the Southland region of New Zealand. In each case, the estimation method is sufficiently robust to cope with groundwater-surface water hydrochemistry vagaries due to sample size and extreme data insufficiency, even when >80% of the data are missing. The estimation of surface water hydrochemistry time series values enabled the evaluation of seasonal variation, and the imputation of lithologies facilitated the evaluation of hydrostratigraphic controls on groundwater-surface water interaction. The robust statistical results for groundwater-surface water models of increasing data complexity provide justification to apply the MSOM technique in other regions of New Zealand and abroad.

  15. Machining Feature Recognition Based on Surface Clustering%基于表面聚类优化的加工特征识别方法

    Institute of Scientific and Technical Information of China (English)

    汤岑书; 褚学宁; 孙习武; 苏於梁

    2009-01-01

    To realize the effective integration of CAD and CAPP system, an approach of machining feature recognition was proposed based on the generation and clustering of surface machining methods. Three kinds of information models, such as manufacturing resource, machined surface and machining method were built. A concept of cutting mode was proposed and used for generating the machining methods of part surfaces. Aiming at minimizing the number of tool type and the number of setups used, an optimal model for surface clustering was established to select the best machining method for every surface. Surfaces which can be simultaneously machined by a common type of tool in the same setup were then recognized as a machining feature. Finally, an example part was used to test the validity and effectiveness of the approach proposed, and the final results illustrate that the approach can effectively solve some problems such as the recognition of intersecting features which are difficult to traditional feature recognition approaches.%为了实现计算机辅助设计与计算机辅助工艺设计系统的有效集成,提出了以表面加工方法生成和聚类优化为基础的加工特征识别新方法.基于加工资源、加工表面和加工方法3类信息模型,引出了切削模式概念和表面加工方法生成的原理.以刀具种类数和零件装夹次数最少为目标,建立了表面聚类优化模型,为加工表面选择最优加工方法,并把可用同类刀具、在同一装夹下连续加工的一组表面聚为一个加工特征.通过实例测试,验证了该方法的正确性和有效性.

  16. Design and calibration of a scanning tunneling microscope for large machined surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Grigg, D.A.; Russell, P.E.; Dow, T.A.

    1988-12-01

    During the last year the large sample STM has been designed, built and used for the observation of several different samples. Calibration of the scanner for prope dimensional interpretation of surface features has been a chief concern, as well as corrections for non-linear effects such as hysteresis during scans. Several procedures used in calibration and correction of piezoelectric scanners used in the laboratorys STMs are described.

  17. The classification of machines for vineyard defoliation in relation to production quality

    Directory of Open Access Journals (Sweden)

    Patrik Burg

    2008-01-01

    Full Text Available Defoliation fulfilment in correct terms, range and intensity effects highly on conditions of bunches and quantity of their contentual matters. Due care reduction of foliar surface together with sunshine allows better access of air to the proximity of bunches and their quicker drying up. The development of fungal diseases is not so quick. Notably hold under especially the peril of charging by cluster with Botrytis, whose harvest its possible take away to the later term. Better insolation at the same time abetment by soaking of clusters and degradation of apple acid.It is possible to make one–shot or gradual defoliation. By smaller growers can the defoliation make by hand, or near bigger with mechanization. In both cases constitute costs on implementation indispensable load sum.

  18. Testing the portal imager GLAaS algorithm for machine quality assurance

    Directory of Open Access Journals (Sweden)

    Fogliata A

    2008-05-01

    Full Text Available Abstract Background To report about enhancements introduced in the GLAaS calibration method to convert raw portal imaging images into absolute dose matrices and to report about application of GLAaS to routine radiation tests for linac quality assurance procedures programmes. Methods Two characteristic effects limiting the general applicability of portal imaging based dosimetry are the over-flattening of images (eliminating the "horns" and "holes" in the beam profiles induced by the presence of flattening filters and the excess of backscattered radiation originated by the detector robotic arm supports. These two effects were corrected for in the new version of GLAaS formalism and results are presented to prove the improvements for different beams, detectors and support arms. GLAaS was also tested for independence from dose rate (fundamental to measure dynamic wedges. With the new corrections, it is possible to use GLAaS to perform standard tasks of linac quality assurance. Data were acquired to analyse open and wedged fields (mechanical and dynamic in terms of output factors, MU/Gy, wedge factors, profile penumbrae, symmetry and homogeneity. In addition also 2D Gamma Evaluation was applied to measurement to expand the standard QA methods. GLAaS based data were compared against calculations on the treatment planning system (the Varian Eclipse and against ion chamber measurements as consolidated benchmark. Measurements were performed mostly on 6 MV beams from Varian linacs. Detectors were the PV-as500/IAS2 and the PV-as1000/IAS3 equipped with either the robotic R- or Exact- arms. Results Corrections for flattening filter and arm backscattering were successfully tested. Percentage difference between PV-GLAaS measurements and Eclipse calculations relative doses at the 80% of the field size, for square and rectangular fields larger than 5 × 5 cm2 showed a maximum range variation of -1.4%, + 1.7% with a mean variation of For Dynamic wedges, percentage

  19. Method of calculation and construction of arrangement sketchy of stone-working machine for the processing of geometrically-complex surfaces of wares of large gabarit

    OpenAIRE

    Чемоданов, Петро Арисович

    2016-01-01

    In the article the method of calculation of basic knots and arrangement sketchy of stone-working gantry milling mapping machine is offered with curvilinear working motion of light cart for the processing of geometrically-complex surfaces on the stoning purveyance of large gabarit.

  20. Numerical and Experimental Modelling of Gas Flow and Heat Transfer in the Air Gap of an Electric Machine. Part Ⅱ: Grooved Surfaces

    Institute of Scientific and Technical Information of China (English)

    Maunu KUOSA; Petri SALLINEN; Arttu REUNANEN; Jari BACKMAN; Jaakko LARJOLA; Lasse KOSKELAINEN

    2005-01-01

    The study deals with the cooling of a high-speed electric machine through an air gap with numerical and experimental methods. The rotation speed of the test machine is between 5000~40000 r/min and the machine is cooled by a forced gas flow through the air gap. In the previous part of the research the friction coefficient was measured for smooth and grooved stator cases with a smooth rotor. The heat transfer coefficient was recently calculated by a numerical method and measured for a smooth stator-rotor combination. In this report the cases with axial groove slots at the stator and/or rotor surfaces are studied. Numerical flow simulations and measurements have been done for the test machine dimensions at a large velocity range. At constant mass flow rate the heat transfer coefficients by the numerical method attain bigger values with groove slots on the stator or rotor surfaces. The results by the numerical method have been confirmed with measurements. The RdF-sensor was glued to the stator and rotor surfaces to measure the heat flux through the surface, as well as the temperature.

  1. Generation of helical gears with new surfaces topology by application of CNC machines

    Science.gov (United States)

    Litvin, F. L.; Chen, N. X.; Hsiao, C. L.; Handschuh, Robert F.

    1993-01-01

    Analysis of helical involute gears by tooth contact analysis shows that such gears are very sensitive to angular misalignment that leads to edge contact and the potential for high vibration. A new topology of tooth surfaces of helical gears that enables a favorable bearing contact and a reduced level of vibration is described. Methods for grinding of the helical gears with the new topology are proposed. A TCA (tooth contact analysis) program for simulation of meshing and contact of helical gears with the new topology has been developed. Numerical examples that illustrate the proposed ideas are discussed.

  2. Machine learning approach for automatic quality criteria detection of health web pages.

    Science.gov (United States)

    Gaudinat, Arnaud; Grabar, Natalia; Boyer, Célia

    2007-01-01

    The number of medical websites is constantly growing [1]. Owing to the open nature of the Web, the reliability of information available on the Web is uneven. Internet users are overwhelmed by the quantity of information available on the Web. The situation is even more critical in the medical area, as the content proposed by health websites can have a direct impact on the users' well being. One way to control the reliability of health websites is to assess their quality and to make this assessment available to users. The HON Foundation has defined a set of eight ethical principles. HON's experts are working in order to manually define whether a given website complies with s the required principles. As the number of medical websites is constantly growing, manual expertise becomes insufficient and automatic systems should be used in order to help medical experts. In this paper we present the design and the evaluation of an automatic system conceived for the categorisation of medical and health documents according to he HONcode ethical principles. A first evaluation shows promising results. Currently the system shows 0.78 micro precision and 0.73 F-measure, with 0.06 errors.

  3. Quality control methods for KOOS operational sea surface temperature products

    Institute of Scientific and Technical Information of China (English)

    YANG Chansu; KIM Sunhwa

    2016-01-01

    Sea surface temperature SST obtained from the initial version of the Korea Operational Oceanographic System (KOOS) SST satellite have low accuracy during summer and daytime. This is attributed to the diurnal warming effect. Error estimation of SST data must be carried out to use the real-time forecasting numerical model of the KOOS. This study suggests two quality control methods for the KOOS SST system. To minimize the diurnal warming effect, SSTs of areas where wind speed is higher than 5 m/s were used. Depending on the wind threshold value, KOOS SST data for August 2014 were reduced by 0.15°C. Errors in SST data are considered to be a combination of random, sampling, and bias errors. To estimate bias error, the standard deviation of bias between KOOS SSTs and climatology SSTs were used. KOOS SST data yielded an analysis error standard deviation value similar to OSTIA and NOAA NCDC (OISST) data. The KOOS SST shows lower random and sampling errors with increasing number of observations using six satellite datasets. In further studies, the proposed quality control methods for the KOOS SST system will be applied through more long-term case studies and comparisons with other SST systems.

  4. Chemical surface modification of glass beads for the treatment of paper machine process waters

    Energy Technology Data Exchange (ETDEWEB)

    Jradi, Khalil, E-mail: khalil.jradi@uqtr.c [Centre de Recherche en Pates et Papiers, Universite du Quebec a Trois Rivieres, 3351 boul. des forges, C.P. 500, Trois Rivieres, QC, G9A-5H7 (Canada); Daneault, Claude [Canada Research Chair in Value-Added Paper Manufacturing (Canada); Chabot, Bruno [Centre de Recherche en Pates et Papiers, Universite du Quebec a Trois Rivieres, 3351 boul. des forges, C.P. 500, Trois Rivieres, QC, G9A-5H7 (Canada)

    2011-04-29

    Adsorption of detrimental contaminants on a solid sorbent is proposed to remove these contaminants from process waters to increase water recycling and reduce effluent loads in the papermaking industry. A self-assembly process of attaching (covalent grafting) cationic aminosilane molecules to glass beads was investigated. The existence and the hydrolytic stability of self-assembled monolayers and multilayers were confirmed by X-Ray Photoelectron Spectroscopy and contact angle measurements. Effects of reaction time and curing on aminosilane layer structures are also discussed. The curing step after silanization seems to be crucial in the hydrophobization of the quaternary ammonium silane coated onto glass beads, and curing could affect the final chemical structure of the ammonium groups of grafted organosilane. Results indicated that modified glass beads have a strong hydrophobicity, which is attributed to the hydrophobic property of the longest carbon chain grafted onto the glass surface. Adsorption of a model contaminant (stearic acid) onto chemically modified glass beads was determined using colloidal titration. Hydrophobic interactions could be the main driving force involved between the long carbon chains of stearic acid and the carbon chains of the aminosilane layers on glass bead surfaces. Finally, self-assembly processes applied onto glass beads may have two promising applications for papermaking and self-cleaning systems.

  5. Spring and surface water quality of the Cyprus ophiolites

    Directory of Open Access Journals (Sweden)

    C. Neal

    2002-01-01

    Full Text Available A survey of surface, spring and borehole waters associated with the ophiolite rocks of Cyprus shows five broad water types (1 Mg-HCO3, (2 Na-SO4-Cl-HCO3, (3 Na-Ca-Cl-SO4-OH-CO3, (4 Na-Cl-SO4 and (5 Ca-SO4. The waters represent a progression in chemical reactivity from surface waters that evolve within a groundwater setting due to hydrolysis of the basic/ultrabasic rock as modified by CO2-weathering. An increase in salinity is also observed which is due to mixing with a saline end-member (modified sea-water and dissolution of gypsum/anhydrite. In some cases, the waters have pH values greater than 11. Such high values are associated with low temperature serpentinisation reactions. The system is a net sink for CO2. This feature is related not only to the hydrolysis of the primary minerals in the rock, but also to CaCO3 or Ca-Mg-CO3 solubility controls. Under hyperalkaline conditions, virtually all the carbon dioxide is lost from the water due to the sufficiently high calcium levels and carbonate buffering is then insignificant. Calcium sulphate solubility controls may also be operative when calcium and sulphate concentrations are particularly high. Keywords: Cyprus, Troodos, ophiolite, serpentinisation, spring, stream, water quality, bromide, iodine, boron, trace elements, hyperalkaline.

  6. Removal performance and water quality analysis of paper machine white water in a full-scale wastewater treatment plant.

    Science.gov (United States)

    Shi, Shuai; Wang, Can; Fang, Shuai; Jia, Minghao; Li, Xiaoguang

    2016-09-29

    Paper machine white water is generally characterized as a high concentration of suspended solids and organic matters. A combined physicochemical-biological and filtration process was used in the study for removing pollutants in the wastewater. The removal efficiency of the pollutant in physicochemical and biological process was evaluated, respectively. Furthermore, advanced technology was used to analyse the water quality before and after the process treatment. Experimental results showed that the removal efficiency of suspend solids (SS) of the system was above 99%, while the physicochemical treatment in the forepart of the system had achieved about 97%. The removal efficiency of chemical oxygen demand (COD) and colour had the similar trend after physicochemical treatment and were corresponding to the proportion of suspended and the near-colloidal organic matter in the wastewater. After biological treatment, the removal efficiency of COD and colour achieved were about 97% and 90%, respectively. Furthermore, molecular weight (MW) distribution analysis showed that after treatment low MW molecules (chromatography/mass spectrometry showed that the composition of organic matter in the wastewater was not complicated. Methylsiloxanes were the typical organic components in the raw wastewater and most of them were removed after treatment.

  7. Predicting the Ecological Quality Status of Marine Environments from eDNA Metabarcoding Data Using Supervised Machine Learning.

    Science.gov (United States)

    Cordier, Tristan; Esling, Philippe; Lejzerowicz, Franck; Visco, Joana; Ouadahi, Amine; Martins, Catarina; Cedhagen, Tomas; Pawlowski, Jan

    2017-08-15

    Monitoring biodiversity is essential to assess the impacts of increasing anthropogenic activities in marine environments. Traditionally, marine biomonitoring involves the sorting and morphological identification of benthic macro-invertebrates, which is time-consuming and taxonomic-expertise demanding. High-throughput amplicon sequencing of environmental DNA (eDNA metabarcoding) represents a promising alternative for benthic monitoring. However, an important fraction of eDNA sequences remains unassigned or belong to taxa of unknown ecology, which prevent their use for assessing the ecological quality status. Here, we show that supervised machine learning (SML) can be used to build robust predictive models for benthic monitoring, regardless of the taxonomic assignment of eDNA sequences. We tested three SML approaches to assess the environmental impact of marine aquaculture using benthic foraminifera eDNA, a group of unicellular eukaryotes known to be good bioindicators, as features to infer macro-invertebrates based biotic indices. We found similar ecological status as obtained from macro-invertebrates inventories. We argue that SML approaches could overcome and even bypass the cost and time-demanding morpho-taxonomic approaches in future biomonitoring.

  8. Grupos electrógenos y calidad de la energía; Reciprocating Machines and Power Quality

    Directory of Open Access Journals (Sweden)

    Marielys Francisco Fernández

    2011-02-01

    Full Text Available Entre las tecnologías de mayor difusión que hoy día se utilizan dentro de la generación distribuida (GDestán los grupos electrógenos (GE. La presencia de los GE en cualquiera de sus formas de explotación,exige un análisis de los problemas que puedan presentarse por su presencia; uno de estos problemas estárelacionado con la calidad de la energía eléctrica (CEL. El presente trabajo expone los primeros resultadosde un estudio que va dirigido a buscar respuestas sobre este tema ante diferentes tipos de perturbacionesque pueden presentarse en la red: Cortocircuito y variación de la tensión en los terminales del GE y ladesconexión súbita de la carga (rechazo de carga. Reciprocating machine (RM is one of the technology more used on distributed generation (DG. Thepresence of RM not manner its operation form need an analysis about differents problems: One of them isrelated with power quality (PQ. First results obained inside one study directed to obtain answers aboutdifferents perturbations for the RM presence like shortcircuit and voltage variation on RM termianls andrejected charge is presented in this paper. 

  9. ECG quality assessment based on a kernel support vector machine and genetic algorithm with a feature matrix

    Institute of Scientific and Technical Information of China (English)

    Ya-tao ZHANG; Cheng-yu LIU; Shou-shui WEI; Chang-zhi WEI; Fei-fei LIU

    2014-01-01

    We propose a systematic ECG quality classification method based on a kernel support vector machine (KSVM) and genetic algorithm (GA) to determine whether ECGs collected via mobile phone are acceptable or not. This method includes mainly three modules, i.e., lead-fall detection, feature extraction, and intelligent classification. First, lead-fall detection is executed to make the initial classification. Then the power spectrum, baseline drifts, amplitude difference, and other time-domain features for ECGs are analyzed and quantified to form the feature matrix. Finally, the feature matrix is assessed using KSVM and GA to determine the ECG quality classification results. A Gaussian radial basis function (GRBF) is employed as the kernel function of KSVM and its performance is compared with that of the Mexican hat wavelet function (MHWF). GA is used to determine the optimal parameters of the KSVM classifier and its performance is compared with that of the grid search (GS) method. The performance of the proposed method was tested on a database from PhysioNet/Computing in Cardiology Challenge 2011, which includes 1500 12-lead ECG recordings. True positive (TP), false positive (FP), and classification accuracy were used as the assessment indices. For training database set A (1000 recordings), the optimal results were obtained using the combination of lead-fall, GA, and GRBF methods, and the corresponding results were:TP 92.89%, FP 5.68%, and classification accuracy 94.00%. For test database set B (500 recordings), the optimal results were also obtained using the combination of lead-fall, GA, and GRBF methods, and the classification accuracy was 91.80%.

  10. To address surface reaction network complexity using scaling relations machine learning and DFT calculations

    Science.gov (United States)

    Ulissi, Zachary W.; Medford, Andrew J.; Bligaard, Thomas; Nørskov, Jens K.

    2017-01-01

    Surface reaction networks involving hydrocarbons exhibit enormous complexity with thousands of species and reactions for all but the very simplest of chemistries. We present a framework for optimization under uncertainty for heterogeneous catalysis reaction networks using surrogate models that are trained on the fly. The surrogate model is constructed by teaching a Gaussian process adsorption energies based on group additivity fingerprints, combined with transition-state scaling relations and a simple classifier for determining the rate-limiting step. The surrogate model is iteratively used to predict the most important reaction step to be calculated explicitly with computationally demanding electronic structure theory. Applying these methods to the reaction of syngas on rhodium(111), we identify the most likely reaction mechanism. Propagating uncertainty throughout this process yields the likelihood that the final mechanism is complete given measurements on only a subset of the entire network and uncertainty in the underlying density functional theory calculations. PMID:28262694

  11. Effects of industrial microcomputer use in control systems for machines and conveyors in surface mining

    Energy Technology Data Exchange (ETDEWEB)

    Borczyk, Z.; Rosseger, A. (Poltegor-Instytut, Wroclaw (Poland))

    1991-01-01

    Evaluates use of the ComPan Pzaz microcomputers manufactured in Poland for control of bucket wheel excavators without thrust action and for belt conveyors used in brown coal surface mines in Poland. The microcomputer consists of 14 standard microprocessor controller modules and 4 specialized modules. Structure of the control system, types of operations controlled by the system and effects of computerized control on safety and efficiency of operation of bucket wheel excavators are analyzed. Use of the ComPan Pzaz microcomputers for control of steep-angle conveyor systems (with a drive power from 1,000 kW to 4,000 kW) is evaluated. The system controls conveyor start-up and conveyor braking. Selected aspects of ComPan Pzaz reliability and service are also discussed. 2 refs.

  12. To address surface reaction network complexity using scaling relations machine learning and DFT calculations

    Science.gov (United States)

    Ulissi, Zachary W.; Medford, Andrew J.; Bligaard, Thomas; Nørskov, Jens K.

    2017-03-01

    Surface reaction networks involving hydrocarbons exhibit enormous complexity with thousands of species and reactions for all but the very simplest of chemistries. We present a framework for optimization under uncertainty for heterogeneous catalysis reaction networks using surrogate models that are trained on the fly. The surrogate model is constructed by teaching a Gaussian process adsorption energies based on group additivity fingerprints, combined with transition-state scaling relations and a simple classifier for determining the rate-limiting step. The surrogate model is iteratively used to predict the most important reaction step to be calculated explicitly with computationally demanding electronic structure theory. Applying these methods to the reaction of syngas on rhodium(111), we identify the most likely reaction mechanism. Propagating uncertainty throughout this process yields the likelihood that the final mechanism is complete given measurements on only a subset of the entire network and uncertainty in the underlying density functional theory calculations.

  13. 5-axis numerical control machining of space free-form surfaces%空间自由曲面五轴联动数控加工

    Institute of Scientific and Technical Information of China (English)

    钟建琳; 刘忠和; 杨庆东

    2011-01-01

    介绍了五轴数控机床的运动方式,阐述了空间自由曲面五轴联动数控加工中刀具路径规划的基本方法:参数线法、CC路径截面线法、CL路径截面线法、导动面法等.之后对五轴加工中刀具轴向规划进行了论述:垂直于表面方式、平行于表面方式、倾斜于表面方式.最后归纳总结了刀具干涉的检测与处理的方法,并分别说明了其优缺点和适应范围.%Mode of motion of the 5-axis numerical control machine tools is introduced.Then the basic methods of tool path planning in 5-axis numerical control machining of space free-form surfaces are ex-pounded ,which include parametric method,cutter contact point path and cross-section method,cutter loca-tion point path and cross-section method,guiding surface method.After that,the tool axial orientation is pro-posed,it can be normal to the machining surface,parallel to the machining surface,or inclined to the ma-chining surface. At the end,the cutter interference checking and avoiding methods are summarized,in which the advantages disadvantages and application limitation of each method are discussed.

  14. An investigation of penetrant techniques for detection of machining-induced surface-breaking cracks on monolithic ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Forster, G.A.; Ellingson, W.A.

    1996-02-01

    The purpose of this effort was to evaluate penetrant methods for their ability to detect surface-breaking cracks in monolithic ceramic materials with an emphasis on detection of cracks generated by machining. There are two basic penetrant types, visible and fluorescent. The visible penetrant method is usually augmented by powder developers and cracks detected can be seen in visible light. Cracks detected by fluorescent penetrant are visible only under ultraviolet light used with or without a developer. The developer is basically a powder that wicks up penetrant from a crack to make it more observable. Although fluorescent penetrants were recommended in the literature survey conducted early in this effort, visible penetrants and two non-standard techniques, a capillary gaseous diffusion method under development at the institute of Chemical Physics in Moscow, and the {open_quotes}statiflux{close_quotes} method which involves use of electrically charged particles, were also investigated. SiAlON ring specimens (1 in. diameter, 3/4 in. wide) which had been subjected to different thermal-shock cycles were used for these tests. The capillary gaseous diffusion method is based on ammonia; the detector is a specially impregnated paper much like litmus paper. As expected, visible dye penetrants offered no detection sensitivity for tight, surface-breaking cracks in ceramics. Although the non-standard statiflux method showed promise on high-crack-density specimens, it was ineffective on limited-crack-density specimens. The fluorescent penetrant method was superior for surface-breaking crack detection, but successful application of this procedure depends greatly on the skill of the user. Two presently available high-sensitivity fluorescent penetrants were then evaluated for detection of microcracks on Si{sub 3}N{sub 4} and SiC from different suppliers. Although 50X optical magnification may be sufficient for many applications, 200X magnification provides excellent delectability.

  15. A mathematical model for surface roughness of fluidic channels produced by grinding aided electrochemical discharge machining (G-ECDM)

    National Research Council Canada - National Science Library

    V G Ladeesh; R Manu

    2017-01-01

    Grinding aided electrochemical discharge machining is a hybrid technique, which combines the grinding action of an abrasive tool and thermal effects of electrochemical discharges to remove material...

  16. Two or three machined vs roughened surface dental implants loaded immediately supporting total fixed prostheses: 1-year results from a randomised controlled trial.

    Science.gov (United States)

    Cannizzaro, Gioacchino; Gastaldi, Giorgio; Gherlone, Enrico; Vinci, Raffaele; Loi, Ignazio; Trullenque-Eriksson, Anna; Esposito, Marco

    2017-01-01

    To compare implants with machined vs roughened surfaces placed flapless in totally edentulous jaws and immediately restored with metal-resin screw-retained cross-arch prostheses. Mandibles were rehabilitated with two implants (Fixed-on-2 or Fo2) and maxillae with three implants (Fixed-on-3 or Fo3). Forty edentulous or to be rendered edentulous patients (20 in the mandible and 20 in the maxilla) were randomised to the machined group (20 patients: 10 mandibles and 10 maxillae) and to the roughened group (20 patients: 10 mandibles and 10 maxillae) according to a parallel group design. To be immediately loaded implants had to be inserted with a minimum torque of 60 Ncm. Outcome measures were prosthesis and implant failures, complications and peri-implant marginal bone level changes evaluated up to 1 year post-loading. Flaps were raised in four patients from the machined group. Four prostheses on machined implants and three on roughened implants were delayed for loading because a sufficient insertion torque was not obtained. There were no dropouts 1 year after loading. Two maxillary machined implants were lost in two patients (difference in proportions = 0.10; 95% CI = -0.03 to 0.23; P (Fisher's exact test) = 0.487); one maxillary Fo3 prosthesis on machined implants and one mandibular Fo2 prosthesis on roughened implants had to be remade (difference in proportions = 0; 95% CI = -0.14 to 0.14; P (Fisher's exact test) = 1.000). Five patients with machined implants had six complications vs seven patients who had eight complications at roughened implants (difference in proportions = -0.10; 95% CI = -0.38 to 0.18; P (Fisher's exact test) = 0.731). There were no statistically significant differences for implant failures, prosthetic failures or complications between groups. There were no statistically significant differences for marginal peri-implant bone levels between the two groups (estimate of the difference = -0.06 mm; 95% CI = -0.23 to 0.10; P (ANCOVA) = 0.445), with

  17. When Machines Design Machines!

    DEFF Research Database (Denmark)

    2011-01-01

    Until recently we were the sole designers, alone in the driving seat making all the decisions. But, we have created a world of complexity way beyond human ability to understand, control, and govern. Machines now do more trades than humans on stock markets, they control our power, water, gas...... and food supplies, manage our elevators, microclimates, automobiles and transport systems, and manufacture almost everything. It should come as no surprise that machines are now designing machines. The chips that power our computers and mobile phones, the robots and commercial processing plants on which we...... depend, all are now largely designed by machines. So what of us - will be totally usurped, or are we looking at a new symbiosis with human and artificial intelligences combined to realise the best outcomes possible. In most respects we have no choice! Human abilities alone cannot solve any of the major...

  18. Pulse electrochemical machining on Invar alloy: Optical microscopic/SEM and non-contact 3D measurement study of surface analyses

    Energy Technology Data Exchange (ETDEWEB)

    Kim, S.H.; Choi, S.G.; Choi, W.K.; Yang, B.Y. [School of Mechanical Engineering, Inha University, Incheon 402-751 (Korea, Republic of); Lee, E.S., E-mail: leees@dreamwiz.com [Department of Mechanical Engineering, Inha University, Incheon 402-751 (Korea, Republic of)

    2014-09-30

    Highlights: • Invar alloy was electrochemically polished and then subjected to PECM (Pulse Electro Chemical Machining) in a mixture of NaCl, glycerin, and distilled water. • Optical microscopic/SEM and non-contact 3D measurement study of Invar surface analyses. • Analysis result shows that applied voltage and electrode shape are factors that affect the surface conditions. - Abstract: In this study, Invar alloy (Fe 63.5%, Ni 36.5%) was electrochemically polished by PECM (Pulse Electro Chemical Machining) in a mixture of NaCl, glycerin, and distilled water. A series of PECM experiments were carried out with different voltages and different electrode shapes, and then the surfaces of polished Invar alloy were investigated. The polished Invar alloy surfaces were investigated by optical microscope, scanning electron microscope (SEM), and non-contact 3D measurement (white light microscopes) and it was found that different applied voltages produced different surface characteristics on the Invar alloy surface because of the locally concentrated applied voltage on the Invar alloy surface. Moreover, we found that the shapes of electrode also have an effect on the surface characteristics on Invar alloy surface by influencing the applied voltage. These experimental findings provide fundamental knowledge for PECM of Invar alloy by surface analysis.

  19. A new optical flat surface measurement method based on machine vision and deflectometry

    Science.gov (United States)

    Kewei, E.; Li, Dahai; Yang, Lijie; Guo, Guangrao; Li, Mengyang; Wang, Xuemin; Zhang, Tao; Xiong, Zhao

    2016-10-01

    Phase Measuring Deflectometry(PMD) is a non-contact, high dynamic-range and full-field metrology which becomes a serious competitor to interferometry. However, the accuracy of deflectometry metrology is strongly influenced by the level of the calibrations. Our paper presents a calibration-based PMD method to test optical flat surface with a high accuracy. In our method, a pin-hole camera was set next to the LCD screen which is used to project sinusoidal fringes to the test flat. And the test flat was placed parallel to the direction of the LCD screen, which makes the geometry calibration process are simplified. The photogrammetric methods used in computer vision science was used to calibrate the pin-hole camera by using a checker pattern shown on another LCD display at six different orientations, the intrinsic parameters can be obtained by processing the obtained image of checker patterns. Further, by making the last orientation of checker pattern is aligned at the same position as the test optical flat, the algorithms used in this paper can obtain the mapping relationship between the CCD pixels and the subaperture coordinates on the test optical flat. We test a optical flat with a size of 50mm in diameter using our setup and algorithm. Our experimental results of optical flat figure from low to high order aberrations show a good agreement with that from the Fizeau interferometer.

  20. Use of barium-strontium carbonatite for flux welding and surfacing of mining machines

    Science.gov (United States)

    Kryukov, R. E.; Kozyrev, N. A.; Usoltsev, A. A.

    2017-09-01

    The results of application of barium-strontium carbonatite for modifying and refining iron-carbon alloys, used for welding and surfacing in ore mining and smelting industry, are generalized. The technology of manufacturing a flux additive containing 70 % of barium-strontium carbonatite and 30 % of liquid glass is proposed. Several compositions of welding fluxes based on silicomanganese slag were tested. The flux additive was introduced in an amount of 1, 3, 5 %. Technological features of welding with the application of the examined fluxes are determined. X-ray spectral analysis of the chemical composition of examined fluxes, slag crusts and weld metal was carried out, as well as metallographic investigations of welded joints. The principal possibility of applying barium-strontium carbonatite as a refining and gas-protective additive for welding fluxes is shown. The use of barium-strontium carbonatite reduces the contamination of the weld seam with nonmetallic inclusions: non-deforming silicates, spot oxides and brittle silicates, and increases the desulfurizing capacity of welding fluxes.

  1. Manufacturing Research of Surface Quality and Working Deep Hole Accuracy in the Camshaft

    Directory of Open Access Journals (Sweden)

    A. I. Solov'ev

    2015-01-01

    Full Text Available Study of surface quality and machining accuracy of a deep hole in the camshaft in manufacturing environment is conducted to make recommendations to eliminate emerging stress concentrators on the hole surface after machining and arising cracks while the engine is in operation.So it is important to conduct a comprehensive task-driven study to determine qualitative and quantitative values of arithmetical mean deviation of the surface roughness profile (parameter of height and available stress concentrators, as well as to define regularities of changing accuracy parameters for deep-hole length such as deviation size, radial run-out, and geometric tolerance in cross section. A guide diameter of the drill bushing and an outer diameter of the cutting part of one-sided cut have been determined too.A camshaft casting from ductile iron HF 65-48-1 was processed in the automatic line on the machine "Hȕller" by a drill with the cutting head from the hard alloy VK6 with simultaneously rotating workpiece and tool. The drill was guided through drill bushing from solid alloy VK 15.The measurement results showed that in 53% of samples there were tears and scratches up to 0.15 mm in depth, which could serve as stress concentrators and in the process of operation encourage growth of cracks in the bulk of the camshaft material.A significantly increasing value of the radial run-out size and all six studied harmonic components show that there is a deviation of the hole axis (run from the nominal (specified position and faceting available with their copied (increased values along the entire length of the hole. This is a qualitative confirmation that in processing the holes in parts made from grey cast iron, there is a mechanism of copying errors earlier available.It is found that the size of a clearance between guide diameter of drill bushing and diameter of tool gage ribbon makes 0. 150 mm and almost 3 times exceeds the recommended value.All this reduces resistance

  2. Experimental investigation of active machine tool vibration control

    Science.gov (United States)

    Rojas, J.; Liang, Chen; Geng, Zheng J.

    1996-05-01

    The successful vibration reduction of machine tools during machining process can improve productivity, increase quality, and reduce tool wear. This paper will present our initial investigation in the application of smart material technologies in machine tool vibration control using magnetostrictive actuators and electrorheological elastomer dampers on an industrial Sheldon horizontal lathe. The dynamics of the machining process are first studied, which reveals the complexity in the machine tool vibration response and the challenge to the active control techniques. The active control experiment shows encouraging results. The use of electrorheological elastomer damping device for active/passive vibration control provides significant vibration reduction in the high frequency range and great improvement in the workpiece surface finishing. The research presented in this paper demonstrates that the combination of active and active/passive vibration control techniques is very promising for successful machine tool vibration control.

  3. Effect of tube-electrode inner diameter on electrochemical discharge machining of nickel-based superalloy

    Directory of Open Access Journals (Sweden)

    Zhang Yan

    2016-08-01

    Full Text Available Nickel-based superalloys are widely employed in modern aircraft engines because of their excellent material characteristics, particularly in the fabrication of film cooling holes. However, the high machining requirement of a large number of film cooling holes can be extremely challenging. The hybrid machining technique of tube electrode high-speed electrochemical discharge drilling (TEHECDD has been considered as a promising method for the production of film cooling holes. Compared with any single machining process, this hybrid technique requires the removal of more complex machining by-products, including debris produced in the electrical discharge machining process and hydroxide and bubbles generated in the electrochemical machining process. These by-products significantly affect the machining efficiency and surface quality of the machined products. In this study, tube electrodes in different inner diameters are designed and fabricated, and the effects of inner diameter on the machining efficiency and surface quality of TEHECDD are investigated. The results show that larger inner diameters could effectively improve the flushing condition and facilitate the removal of machining by-products. Therefore, higher material removal efficiency, surface quality, and electrode wear rate could be achieved by increasing the inner diameter of the tube electrode.

  4. Novel in situ mechanical testers to enable integrated metal surface micro-machines.

    Energy Technology Data Exchange (ETDEWEB)

    Follstaedt, David Martin; de Boer, Maarten Pieter; Kotula, Paul Gabriel; Hearne, Sean Joseph; Foiles, Stephen Martin; Buchheit, Thomas Edward; Dyck, Christopher William

    2005-10-01

    The ability to integrate metal and semiconductor micro-systems to perform highly complex functions, such as RF-MEMS, will depend on developing freestanding metal structures that offer improved conductivity, reflectivity, and mechanical properties. Three issues have prevented the proliferation of these systems: (1) warpage of active components due to through-thickness stress gradients, (2) limited component lifetimes due to fatigue, and (3) low yield strength. To address these issues, we focus on developing and implementing techniques to enable the direct study of the stress and microstructural evolution during electrodeposition and mechanical loading. The study of stress during electrodeposition of metal thin films is being accomplished by integrating a multi-beam optical stress sensor into an electrodeposition chamber. By coupling the in-situ stress information with ex-situ microstructural analysis, a scientific understanding of the sources of stress during electrodeposition will be obtained. These results are providing a foundation upon which to develop a stress-gradient-free thin film directly applicable to the production of freestanding metal structures. The issues of fatigue and yield strength are being addressed by developing novel surface micromachined tensile and bend testers, by interferometry, and by TEM analysis. The MEMS tensile tester has a ''Bosch'' etched hole to allow for direct viewing of the microstructure in a TEM before, during, and after loading. This approach allows for the quantitative measurements of stress-strain relations while imaging dislocation motion, and determination of fracture nucleation in samples with well-known fatigue/strain histories. This technique facilitates the determination of the limits for classical deformation mechanisms and helps to formulate a new understanding of the mechanical response as the grain sizes are refined to a nanometer scale. Together, these studies will result in a science

  5. The PLC Control of Vision Detection Machine for Ceramic Sleeve Surface Defects%陶瓷套圈表面质量机器视觉检测系统

    Institute of Scientific and Technical Information of China (English)

    张磊; 陈红; 范维浩

    2011-01-01

    本文在分析陶瓷套圈表面质量机器视觉检测机的系统组成和自动检测工作流程基础上,设计出检测机的气动驱动系统和PLC集成电气控制系统,给出PLC控制程序流程.通过PLC集成机器视觉、气动驱动和步进电机驱动控制系统,实现陶瓷套圈外圆表面缺陷机器视觉检测自动化,自动检测节拍达到2秒/件.%This paper firstly analyzes the mechanical system principle and technological process of the vision detection machine for ceramic sleeve surface quality inspection, and then designs a pneumatic drive system and PLC control system for the machine finally programs a PLC control program to implement the integrating control of machine vision, pneumatic drive system and stepping motor. The automatic cycle time of vision detection implements is 2 sec / piece.

  6. Conductivity as an indicator of surface water quality in the proximity ...

    African Journals Online (AJOL)

    2015-10-05

    Oct 5, 2015 ... Conductivity as an indicator of surface water quality in the ... FeCr smelting did not significantly impact surface water quality, but that surface run-off and/or ..... farming-management/soil-water/salinity/measuring-the-salinity-.

  7. PLASTIC DEFORMATION ON THE MACHINED SURFACE OF STEEL Cr20Ni10MoTi AT DRILLING

    Directory of Open Access Journals (Sweden)

    Jozef Jurko

    2009-07-01

    Full Text Available Information about material machinability is very important for the machining technology. Precise and reliable information on the machinability of a material before it enters the machining process is a necessity, and this brings the verification of technological methods in practice. This article presents the conclusions of machinability tests on austenitic stainless steel according to EN-EU (ISO: steel Cr20Ni10MoTi. This article presents the conclusions of VEGA grant agency at the Ministry of Education SR for supporting research work and co-financing the projects: Grant work #01/3173/2006 with the title „Experimental investigation of cutting zones in drilled and milled stainless steels

  8. Research on CNC Turning System of Aspheric Machining Grinding Wheel

    Institute of Scientific and Technical Information of China (English)

    ZOU Qin; GUO Yin-biao

    2005-01-01

    The technology of machining aspheric surface with high precision is the premise for the application of aspheric surface. The grinding machining with error compensation is a commonly used method to machine aspheric surface, which will directly influence the quality of aspheric workpiece surface. Multifunctional CNC grinding wheel truing system is a four-axis CNC truing system which can be applied to grinding wheel truing. In this system,DSP-based multi-axes motion control card is adopted as the controller, and visual C++ is used as development tool.When the design of hardware and software is completed, the system can implement truing of various grinding wheel with high precision aspheric machining such as plane grinding wheel, arc grinding one, and sphere grinding one.

  9. Advancing of Land Surface Temperature Retrieval Using Extreme Learning Machine and Spatio-Temporal Adaptive Data Fusion Algorithm

    Directory of Open Access Journals (Sweden)

    Yang Bai

    2015-04-01

    Full Text Available As a critical variable to characterize the biophysical processes in ecological environment, and as a key indicator in the surface energy balance, evapotranspiration and urban heat islands, Land Surface Temperature (LST retrieved from Thermal Infra-Red (TIR images at both high temporal and spatial resolution is in urgent need. However, due to the limitations of the existing satellite sensors, there is no earth observation which can obtain TIR at detailed spatial- and temporal-resolution simultaneously. Thus, several attempts of image fusion by blending the TIR data from high temporal resolution sensor with data from high spatial resolution sensor have been studied. This paper presents a novel data fusion method by integrating image fusion and spatio-temporal fusion techniques, for deriving LST datasets at 30 m spatial resolution from daily MODIS image and Landsat ETM+ images. The Landsat ETM+ TIR data were firstly enhanced based on extreme learning machine (ELM algorithm using neural network regression model, from 60 m to 30 m resolution. Then, the MODIS LST and enhanced Landsat ETM+ TIR data were fused by Spatio-temporal Adaptive Data Fusion Algorithm for Temperature mapping (SADFAT in order to derive high resolution synthetic data. The synthetic images were evaluated for both testing and simulated satellite images. The average difference (AD and absolute average difference (AAD are smaller than 1.7 K, where the correlation coefficient (CC and root-mean-square error (RMSE are 0.755 and 1.824, respectively, showing that the proposed method enhances the spatial resolution of the predicted LST images and preserves the spectral information at the same time.

  10. Abdominal strengthening using the AbVice machine as measured by surface electromyographic activation levels.

    Science.gov (United States)

    Avedisian, Lori; Kowalsky, Don S; Albro, Richard C; Goldner, Daniel; Gill, Robert C

    2005-08-01

    Twenty-four college students served as subjects in a study that examined the effect of a prototypical abdominal muscle strengthening device (AbVice) compared with other devices currently on the market. The purpose of the present study was to investigate a prototypical device (AbVice) that incorporates contraction of the hamstring and gluteal musculature in conjunction with the abdominals, which may assist in decreasing activation of the hip flexors by allowing greater activity levels of the abdominal musculature via the theory of reflex inhibition, compared with other devices currently available on the market (AbRoller and AbRocker). The repeated-measures study included 17 women and 7 men who ranged in age from 20-23 years (mean +/- SD age, 21.3 +/- 1.5 years). Each subject underwent a single session of data collection during which they completed 10 repetitions of abdominal crunches per device. Subjects completed 4 different crunch sets (AbRocker, AbRoller, standard crunch, AbVice). Counterbalancing of the device was used to negate the effect of fatigue. Speed of repetitions was ensured via use of a metronome set at 40 b.min(-1) to permit similar contraction times and rest periods between repetitions. Rest between conditions was 3 minutes. Mean activation levels of surface electromyography (EMG) were recorded for each condition at the following locations on the right side of the body: rectus abdominis 2.5 cm superior to the umbilicus, rectus abdominis 2.5 cm inferior to the umbilicus, external oblique abdominis 1.0 cm medial to the anterior superior iliac spine, and external oblique abdominis less than 1.0 cm superior to the inguinal ligament. Mean (SD) activation was 1,165.21 mV (634.60 mV) with the AbVice, 242.92 mV (263.03 mV) with the AbRocker, 753.29 mV (514.80 mV) with the standard crunch, and 757.67 mV (542.85 mV) with the AbRoller. Broken down by sex, women had the following mean (SD) EMG values: 1,079.76 mV (705.02 mV) with the AbVice, 680.35 mV (535.35 m

  11. A method for the evaluation of image quality according to the recognition effectiveness of objects in the optical remote sensing image using machine learning algorithm.

    Directory of Open Access Journals (Sweden)

    Tao Yuan

    Full Text Available Objective and effective image quality assessment (IQA is directly related to the application of optical remote sensing images (ORSI. In this study, a new IQA method of standardizing the target object recognition rate (ORR is presented to reflect quality. First, several quality degradation treatments with high-resolution ORSIs are implemented to model the ORSIs obtained in different imaging conditions; then, a machine learning algorithm is adopted for recognition experiments on a chosen target object to obtain ORRs; finally, a comparison with commonly used IQA indicators was performed to reveal their applicability and limitations. The results showed that the ORR of the original ORSI was calculated to be up to 81.95%, whereas the ORR ratios of the quality-degraded images to the original images were 65.52%, 64.58%, 71.21%, and 73.11%. The results show that these data can more accurately reflect the advantages and disadvantages of different images in object identification and information extraction when compared with conventional digital image assessment indexes. By recognizing the difference in image quality from the application effect perspective, using a machine learning algorithm to extract regional gray scale features of typical objects in the image for analysis, and quantitatively assessing quality of ORSI according to the difference, this method provides a new approach for objective ORSI assessment.

  12. Machining parameter optimization of C/SiC composites using high power picosecond laser

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Ruoheng; Li, Weinan [State Key Laboratory of Transient Optics and Photonics, Xi’an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi’an, Shaanxi 10068 (China); Liu, Yongsheng, E-mail: yongshengliu@nwpu.edu.cn [Science and Technology on Thermostructure Composite Materials Laboratory, Northwestern Polytechnical University, Xi’an, Shaannxi 710072 (China); Wang, Chunhui; Wang, Jing [Science and Technology on Thermostructure Composite Materials Laboratory, Northwestern Polytechnical University, Xi’an, Shaannxi 710072 (China); Yang, Xiaojun [State Key Laboratory of Transient Optics and Photonics, Xi’an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi’an, Shaanxi 10068 (China); Cheng, Laifei, E-mail: liuys99067@163.com [Science and Technology on Thermostructure Composite Materials Laboratory, Northwestern Polytechnical University, Xi’an, Shaannxi 710072 (China)

    2015-03-01

    Highlights: • We found that the helical line width and the helical line spacing, machining time and the scanning speed on the surface morphology of machined holes had remarkable effects on the qualities of micro-holes such as shape and depth. • The debris consisted of C, Si and O was observed on the machined surface. The Si−C bonds of the SiC matrix transformed into Si−O bonds after machined. - Abstract: Picosecond laser is an important machining technology for high hardness materials. In this paper, high power picosecond laser was utilized to drill micro-holes in C/SiC composites, and the effects of different processing parameters including the helical line width and spacing, machining time and scanning speed were discussed. To characterize the qualities of machined holes, scanning electron microscope (SEM) was used to analyze the surface morphology, energy dispersive spectroscopy (EDS) and X-ray photoelectric spectroscopy (XPS) were employed to describe the element composition change between the untreated and laser-treated area. The experimental results indicated that all parameters mentioned above had remarkable effects on the qualities of micro-holes such as shape and depth. Additionally, the debris consisted of C, Si and O was observed on the machined surface. The Si−C bonds of the SiC matrix transformed into Si−O bonds after machined. Furthermore, the physical process responsible for the mechanism of debris formation was discussed as well.

  13. Machining strategy choice: performance VIEWER

    CERN Document Server

    Tapie, Laurent; Anselmetti, Bernard

    2009-01-01

    Nowadays high speed machining (HSM) machine tool combines productivity and part quality. So mould and die maker invested in HSM. Die and mould features are more and more complex shaped. Thus, it is difficult to choose the best machining strategy according to part shape. Geometrical analysis of machining features is not sufficient to make an optimal choice. Some research show that security, technical, functional and economical constrains must be taken into account to elaborate a machining strategy. During complex shape machining, production system limits induce feed rate decreases, thus loss of productivity, in some part areas. In this paper we propose to analyse these areas by estimating tool path quality. First we perform experiments on HSM machine tool to determine trajectory impact on machine tool behaviour. Then, we extract critical criteria and establish models of performance loss. Our work is focused on machine tool kinematical performance and numerical controller unit calculation capacity. We implement...

  14. Machinability of advanced materials

    CERN Document Server

    Davim, J Paulo

    2014-01-01

    Machinability of Advanced Materials addresses the level of difficulty involved in machining a material, or multiple materials, with the appropriate tooling and cutting parameters.  A variety of factors determine a material's machinability, including tool life rate, cutting forces and power consumption, surface integrity, limiting rate of metal removal, and chip shape. These topics, among others, and multiple examples comprise this research resource for engineering students, academics, and practitioners.

  15. MECHANISMS OF CUTTING BLADE WEAR AND THEIR INFLUENCE ON CUTTING ABILITY OF THE TOOL DURING MACHINING OF SPECIAL ALLOYS

    Directory of Open Access Journals (Sweden)

    Tomáš Zlámal

    2016-09-01

    Full Text Available With increased requirements for quality and shelf life of machined parts there is also a higher share of the use of material with specific properties that are identified by the term “superalloys”. These materials differ from common steels by mechanical and physical properties that cause their worse machinability. During machining of “superalloys” worse machinability has negative influence primarily on the amount of cutting edge wear, which shortens durability of the cutting tool. The goal of experimental activity shown in this contribution is to determine individual mechanisms of the cutting edge wear and their effects on the cutting ability during high speed machining of nickel superalloy. A specific exchangeable cutting insert made from cubic boric nitride was used for machining of the 625 material according to ASM 5666F. The criteria to evaluate cutting ability and durability of the cutting tool became selected parameters of surface integrity and quality of the machined surface.

  16. A level set methodology for predicting the effect of mask wear on surface evolution of features in abrasive jet micro-machining

    Science.gov (United States)

    Burzynski, T.; Papini, M.

    2012-07-01

    A previous implementation of narrow-band level set methodology developed by the authors was extended to allow for the modelling of mask erosive wear in abrasive jet micro-machining (AJM). The model permits the prediction of the surface evolution of both the mask and the target simultaneously, by representing them as a hybrid and continuous mask-target surface. The model also accounts for the change in abrasive mass flux incident to both the target surface and, for the first time, the eroding mask edge, that is brought about by the presence of the mask edge itself. The predictions of the channel surface and eroded mask profiles were compared with measurements on channels machined in both glass and poly-methyl-methacrylate (PMMA) targets at both normal and oblique incidence, using tempered steel and elastomeric masks. A much better agreement between the predicted and measured profiles was found when mask wear was taken into account. Mask wear generally resulted in wider and deeper glass target profiles and wider PMMA target profiles, respectively, when compared to cases where no mask wear was present. This work has important implications for the AJM of complex MEMS and microfluidic devices that require longer machining times.

  17. Post-machining thermal treatment after surface finishing of hardened steels: Kinetics of XRD line width reduction and improvement in rolling contact lifetime under mixed friction conditions

    Energy Technology Data Exchange (ETDEWEB)

    Gegner, Juergen [SKF GmbH, Department of Material Physics, Ernst-Sachs-Str. 5, D-97424 Schweinfurt (Germany)

    2008-07-01

    Hard surface finishing represents the final manufacturing step for functional areas of machine elements in state-of-the-art production. Raceways of rolling bearing rings are ground and honed to the required low roughness. Plastic deformation is restricted to a narrow edge zone of the hardened steel. Reheating of the machined components below the martensite tempering or bainite transformation temperature results in a marked decrease of the XRD line width on the surface. The investigated samples are made of through-hardened standard bearing steel 100Cr6 (international denotation: SAE 52100). On the basis of a material model that explains the effect as a complex diffusion process of dislocational carbon segregation, i.e. static strain aging, the measured kinetics of the XRD line width reduction is simulated by an Arrhenius-type equation, which describes the rate-controlling reaction step of temper carbide dissolution. The formation of a small white-etching surface layer of around 1 um thickness by post-machining thermal treatment (PMTT) strongly supports this assumption. First rig tests suggest a considerable increase of the lifetime of Hertzian loaded elements that operate under heavy surface loading. PMTT performed in air leads to a beneficial nanoscaled oxide layer.

  18. Experimental Investigation of Effect of Process Parameters on Mrr and Surface Roughness In Turning Operation on Conventional Lathe Machine For Aluminum 6082 Grade Material Using Taguchi Method

    Directory of Open Access Journals (Sweden)

    Mihir T. Patel

    2014-01-01

    Full Text Available In this study, the effect of the machining parameters like spindle speed, feed, depth of cut and nose radius on material removal rate and surface roughness are investigated, also optimum process parameters are studied. An L8 orthogonal array (mixed level design, analysis of variance (ANOVA and the signal –to-noise (S/N ratio are used in this study. Mixed levels of machining parameters are used and experiments are done on conventional lathe machine. Aluminum Alloy - Al 6082 grade material is used in high stress applications, Trusses, Bridges, Cranes, Transport applications, Ore skips, Beer barrels, Milk churns etc. The most significant parameters for material removal rate are speed, depth of cut and least significant factor for MRR is nose radius For surface roughness speed, nose radius are the most significant parameters and least significant factor for surface roughness is depth of cut. The mathematical model obtained as a result of regression analysis can be reliable to predict MRR and surface roughness Ra.

  19. Quantify work load and muscle functional activation patterns in neck-shoulder muscles of female sewing machine operators using surface electromyogram.

    Science.gov (United States)

    Zhang, Fei-Ruo; He, Li-Hua; Wu, Shan-Shan; Li, Jing-Yun; Ye, Kang-Pin; Wang, Sheng

    2011-11-01

    Work-related musculoskeletal disorders (WMSDs) have high prevalence in sewing machine operators employed in the garment industry. Long work duration, sustained low level work and precise hand work are the main risk factors of neck-shoulder disorders for sewing machine operators. Surface electromyogram (sEMG) offers a valuable tool to determine muscle activity (internal exposure) and quantify muscular load (external exposure). During sustained and/or repetitive muscle contractions, typical changes of muscle fatigue in sEMG, as an increase in amplitude or a decrease as a shift in spectrum towards lower frequencies, can be observed. In this paper, we measured and quantified the muscle load and muscular activity patterns of neck-shoulder muscles in female sewing machine operators during sustained sewing machine operating tasks using sEMG. A total of 18 healthy women sewing machine operators volunteered to participate in this study. Before their daily sewing machine operating task, we measured the maximal voluntary contractions (MVC) and 20%MVC of bilateral cervical erector spinae (CES) and upper trapezius (UT) respectively, then the sEMG signals of bilateral UT and CES were monitored and recorded continuously during 200 minutes of sustained sewing machine operating simultaneously which equals to 20 time windows with 10 minutes as one time window. After 200 minutes' work, we retest 20%MVC of four neck-shoulder muscles and recorded the sEMG signals. Linear analysis, including amplitude probability distribution frequency (APDF), amplitude analysis parameters such as roof mean square (RMS) and spectrum analysis parameter as median frequency (MF), were used to calculate and indicate muscle load and muscular activity of bilateral CES and UT. During 200 minutes of sewing machine operating, the median load for the left cervical erector spinae (LCES), right cervical erector spinae (RCES), left upper trapezius (LUT) and right upper trapezius (RUT) were 6.78%MVE, 6.94%MVE, 6

  20. Very high precision survey equipment for great distances Surface surveys used to map out the surface network and the tunnelling machines then gyroscopically steered underground.

    CERN Multimedia

    1983-01-01

    At the beginning of the 1980s, CERN embarked on the enormous Large Electron-Positron Collider construction project. The excavation of the 27-kilometre LEP tunnel was a huge technical challenge. The tunnel-boring machines excavated the tunnel in 3.3 km octants and had to be operated with extraordinary precision to ensure that they reached their destination - the bottom of the next vertical shaft - precisely on target. The tunnel was excavated before high-performance instruments were developed for the construction of the Channel Tunnel. As no firms were willing to perform the surveying work, CERN's own surveyors, with experience from the SPS behind them, took up the challenge. At the surface, the surveyors established the world's most accurate geodetic network, performing measurements to an accuracy of 10-7, or 1mm per 10 km, using the Terrameter (see photo). The excavation of the tunnel was completed in 1988 and the finished tunnel's trajectory was found to diverge from the theoretical value specified by the p...

  1. Surface quality of cold rolling aluminum strips under lubrication condition

    Institute of Scientific and Technical Information of China (English)

    Jianlin Sun; Wang Lu; Yanli Ma; Qingbing Shi; Aihua Zhang; Jian Li

    2008-01-01

    The effects of oil fill on the rolled surface, including surface roughness and topography, were investigated during cold rolling of aluminum strips. Various mineral oils with viscosities from 0.10 to 1.6 Pa.s were used to obtain different oil film thick-nesses. Results from experiment and calculation show that the thicker oil film protects the initial roughening surface so that it leads to an increase in roughness of the rolled surface, in particular when the surface roughness has the character of direction. The rolled surface roughness was determined by λ, which is the ratio of oil film thickness to the combined surface roughness. When λ > 3, the rolled surface roughness increases rapidly with the increase in oil viscosity, whereas the surface roughening has already occurred when λ < 3, but the increase of the rolled surface roughness with increasing viscosity is not distinct.

  2. Sea Surface Height, Absolute, Aviso, 0.25 degrees, Global, Science Quality

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Aviso Absolute Sea Surface Height is the Sea Surface Height Deviation plus the long term mean dynamic height. This is Science Quality data.

  3. Tribology in secondary wood machining

    Energy Technology Data Exchange (ETDEWEB)

    Ko, P.L.; Hawthorne, H.M.; Andiappan, J.

    1998-07-01

    Secondary wood manufacturing covers a wide range of products from furniture, cabinets, doors and windows, to musical instruments. Many of these are now mass produced in sophisticated, high speed numerical controlled machines. The performance and the reliability of the tools are key to an efficient and economical manufacturing process as well as to the quality of the finished products. A program concerned with three aspects of tribology of wood machining, namely, tool wear, tool-wood friction characteristics and wood surface quality characterization, was set up in the Integrated Manufacturing Technologies Institute (IMTI) of the National Research Council of Canada. The studies include friction and wear mechanism identification and modeling, wear performance of surface-engineered tool materials, friction-induced vibration and cutting efficiency, and the influence of wear and friction on finished products. This research program underlines the importance of tribology in secondary wood manufacturing and at the same time adds new challenges to tribology research since wood is a complex, heterogeneous, material and its behavior during machining is highly sensitive to the surrounding environments and to the moisture content in the work piece.

  4. Quality Control and Application of Hemodialysis Machines%血液透析机的主要参数设定和检测方法

    Institute of Scientific and Technical Information of China (English)

    唐立源; 朱兴喜

    2011-01-01

    Objective Ensure safety of patients during treatment and normal operations by study applications, parameters, and the basic methods of quality control of hemodialysis machine. Methods Study treatment effect of hemodialysis machines in different parameters and refer "Quality Inspection of hemodialysis equipment technical specifications". Results For three different types of hemodialysis machines for testing and comparison, parameters are all qualified. Conclusion To ensure the safety of hemodialysis treatment, it is important to understand theory of hemodialysis machine, establishment of periodic quality control is important.%目的 研究血液透析机的应用、各种参数、及质控的基本方法,从而确保血液透析机在为患者治疗过程中的安全及正常运转.方法 研究血液透析机在不同参数下工作对人体的影响,并根据《血液透析、血液透析滤过和血液滤过设备的安全专用要求》GB 9706.2-2003,对血液透析机进行质量检测.结果 对3种型号的血液透析机进行检测,并进行对比,参数皆为合格.结论 作为确保血液透析安全的重要方法和手段,进一步了解血液透析,并建立周期性的质量控制具有重要意义.

  5. Investigation on surface morphology model of Si3N4 ceramics for rotary ultrasonic grinding machining based on the neural network

    Science.gov (United States)

    Jing, Juntao; Feng, Pingfa; Wei, Shiliang; Zhao, Hong

    2017-02-01

    Si3N4 ceramics parts surface morphology is related with surface friction and wear properties directly. Poor surface morphology will result in friction coefficient increases, strength decreases, and even lead to component failures. In order to improve Si3N4 surface morphology, it is necessary to investigate on the relationship model between the surface morphology and process parameters. In the paper, rotary ultrasonic grinding machining (RUGM) was taken as object to establish the model based on back propagation (BP) neural network. However, the nonlinear relationship of the model is complex, and the traditional algorithm cannot realize satisfying results. So an improved BP neural network algorithm based on Powell method has been proposed. The paper gives the theory and calculation flow of the algorithm. It is found the algorithm can accelerate the iteration speed and improve iteration accuracy. The investigation results provide the support for surface morphology optimization.

  6. Machinability study on discontinuously reinforced aluminium composites (DRACs using response surface methodology and Taguchi’s design of experiments under dry cutting condition

    Directory of Open Access Journals (Sweden)

    Raviraj Shetty1

    2008-03-01

    Full Text Available The development of metal matrix composites with discontinuous reinforcement represents a well-established method for improving the strength and stiffness of a material. This paper discusses the use of Taguchi’s design of experiments and response surface methodology (RSM for minimising the surface roughness in turning of discontinuously reinforced aluminium composites (DRACs having aluminum alloy 6061 as the matrix and containing 15 vol. % of silicon carbide particles with a mean diameter of 25µm under dry cutting condition. The measured results are then collected and analysed with the help of a commercial software package MINITAB15. The experiments are conducted using Taguchi’s experimental design technique. The matrices of test conditions include cutting speed, feed rates and depth of cut. The effect of cutting parameters on surface roughness is evaluated and the optimum cutting condition for minimising the surface roughness is determined. A second-order model is established between the cutting parameters and the surface roughness using RSM. The experimental results reveal that the most significant machining parameter for surface roughness is feed, followed by cutting speed. The predicted values and measured values are fairly close, which indicates that the developed model can be effectively used to predict the surface roughness in the machining of DRACs.

  7. Machining of Metal Matrix Composites

    CERN Document Server

    2012-01-01

    Machining of Metal Matrix Composites provides the fundamentals and recent advances in the study of machining of metal matrix composites (MMCs). Each chapter is written by an international expert in this important field of research. Machining of Metal Matrix Composites gives the reader information on machining of MMCs with a special emphasis on aluminium matrix composites. Chapter 1 provides the mechanics and modelling of chip formation for traditional machining processes. Chapter 2 is dedicated to surface integrity when machining MMCs. Chapter 3 describes the machinability aspects of MMCs. Chapter 4 contains information on traditional machining processes and Chapter 5 is dedicated to the grinding of MMCs. Chapter 6 describes the dry cutting of MMCs with SiC particulate reinforcement. Finally, Chapter 7 is dedicated to computational methods and optimization in the machining of MMCs. Machining of Metal Matrix Composites can serve as a useful reference for academics, manufacturing and materials researchers, manu...

  8. Retrieval of aerosol optical depth from surface solar radiation measurements using machine learning algorithms, non-linear regression and a radiative transfer-based look-up table

    Science.gov (United States)

    Huttunen, Jani; Kokkola, Harri; Mielonen, Tero; Esa Juhani Mononen, Mika; Lipponen, Antti; Reunanen, Juha; Vilhelm Lindfors, Anders; Mikkonen, Santtu; Erkki Juhani Lehtinen, Kari; Kouremeti, Natalia; Bais, Alkiviadis; Niska, Harri; Arola, Antti

    2016-07-01

    In order to have a good estimate of the current forcing by anthropogenic aerosols, knowledge on past aerosol levels is needed. Aerosol optical depth (AOD) is a good measure for aerosol loading. However, dedicated measurements of AOD are only available from the 1990s onward. One option to lengthen the AOD time series beyond the 1990s is to retrieve AOD from surface solar radiation (SSR) measurements taken with pyranometers. In this work, we have evaluated several inversion methods designed for this task. We compared a look-up table method based on radiative transfer modelling, a non-linear regression method and four machine learning methods (Gaussian process, neural network, random forest and support vector machine) with AOD observations carried out with a sun photometer at an Aerosol Robotic Network (AERONET) site in Thessaloniki, Greece. Our results show that most of the machine learning methods produce AOD estimates comparable to the look-up table and non-linear regression methods. All of the applied methods produced AOD values that corresponded well to the AERONET observations with the lowest correlation coefficient value being 0.87 for the random forest method. While many of the methods tended to slightly overestimate low AODs and underestimate high AODs, neural network and support vector machine showed overall better correspondence for the whole AOD range. The differences in producing both ends of the AOD range seem to be caused by differences in the aerosol composition. High AODs were in most cases those with high water vapour content which might affect the aerosol single scattering albedo (SSA) through uptake of water into aerosols. Our study indicates that machine learning methods benefit from the fact that they do not constrain the aerosol SSA in the retrieval, whereas the LUT method assumes a constant value for it. This would also mean that machine learning methods could have potential in reproducing AOD from SSR even though SSA would have changed during

  9. Experimental Investigation into the Effect of Ball End Milling Parameters on Surface Integrity of Inconel 718

    Science.gov (United States)

    Bhopale, Nandkumar N.; Joshi, Suhas S.; Pawade, Raju S.

    2015-02-01

    In machining of Inconel 718, various difficulties such as increased tool wear and poor machined surface quality are frequently encountered due to its high temperature strength and poor thermal properties. This work considers the effect of number of passes and the machining environment on the machined surface quality in ball end milling of Inconel 718, which hitherto has not been adequately understood. To this effect, extensive experimentation has been carried out to analyze machined surface quality and integrity in terms of surface roughness, surface damage, and microhardness variation in the machined surfaces. The machined surfaces show formation of distinct bands as a function of instantaneous machining parameters along the periphery of cutting tool edge. A distinct variation is also observed in the measured values of surface roughness and microhardness in these regions. The minimum surface roughness is obtained in the stable cutting zone and it increases toward the periphery of the cutter on band #2 and band #3. Microhardness of depth beneath the machined surface shows that the machining affected zone varies from 60 to 100 µm in ball end milling under various machining conditions.

  10. Error Analysis and Compensation of Digital Polishing Machine for Electric Kettle Surface%电水壶曲面数字化抛光机床的误差分析及补偿

    Institute of Scientific and Technical Information of China (English)

    吴昌林; 李强; 王韦; 翟金良

    2012-01-01

    A Digital polishing machine used to polish electric kettle surface is introduced in order to resolve the problems of serious pollution, low efficiency and unstable quality with the manual polishing of the kettle surface. The paper describes the error's reason and the influence caused by the stepping motor lost time of the machine and then proposes the method that the acceleration and deceleration are controlled by the stepping motor base on 51SCM to eliminate the error. In the same time, the feasibility of these methods is confirmed through experiments.%为了解决电水壶手工抛磨污染大、效率低、抛磨效果不稳定等问题,介绍了一种电水壶曲面数字化抛光机床,阐述了该机床由步进电动机失步造成的误差的原因及对各方面的影响,提出一种基于51系列单片机的步进电动机加减速控制方法来消除该误差,同时通过实验证实了该方法的可行性.

  11. High-Quality Alkyl Monolayers on Silicon Surfaces

    NARCIS (Netherlands)

    Sieval, A.B.; Linke, R.; Zuilhof, H.; Sudh"lter, E.J.R.

    2000-01-01

    Covalent attachment of functionalized monolayers onto silicon surfaces (see Figure for examples) is presented here as a strategy for surface modification. The preparation and structure of both unfunctionalized and functionalized alkyl-based monolayers are described, as are potential applications,

  12. Micro hole machining of borosilicate glass through electrochemical discharge machining (ECDM)

    Energy Technology Data Exchange (ETDEWEB)

    Yang, C.T.; Ho, S.S.; Yan, B.H. [National Central Univ. (Taiwan). Dept. of Mechanical Engineering

    2001-07-01

    The borosilicate glass serves as the substrates of the micro sensors owing to their excellent anodic bonding properties. To build up the electrical through channel and connect the internal system with the environment, micro holes should be drilled on the substrates. This investigation describes a novel process that combines micro electrical discharge machining (micro EDM) and electrochemical discharge machining (ECDM) to drill micro holes on the borosilicate glass plate. Experimental investigation of the novel process includes fabrication of micro tools via micro EDM and machining characteristics of the borosilicate glass by ECDM. This study also analyzes the basic material removal mechanism in the ECDM process. Four stages are identified in the ECDM process via rapid photography. Etching reaction is important in the machining mechanism of ECDM through SEM and EDX analysis. Unlike conventional EDM, the key reason for improving material removal rate and surface roughness is the etching reaction in the ECDM process. Also discussed herein are the effects of machining parameters, such as applied voltage, electrolytes, concentration of electrolytes, and temperature of electrolytes in ECDM. Furthermore, machining time, hole expansion and the surface roughness of inner holes are measured to assess hole quality. This novel process can improve material removal rate and surface roughness to 1.5 mm/min and 0.08 {mu}m, Ra. Experimental results demonstrate that this process is excellent for fabricating micro holes on the borosilicate glass for MEMS. (orig.)

  13. Surface quality of a 1m Zerodur part using an effective grinding mode

    Science.gov (United States)

    Tonnellier, X.; Shore, P.; Morantz, P.; Orton, D.

    2008-09-01

    A new ultra precision large optics grinding machine, BoX (R) , has been developed at Cranfield University. This machine is located at the UK's Ultra Precision Surfaces laboratory at the OpTIC Technium, North Wales. This machine offers a rapid and economic solution for grinding large off-axis aspherical and free-form optical components. This paper presents an analysis of surface and subsurface damage assessments of Zerodur(R) ground using diamond resin bonded grinding wheels. Zerodur(R) was tested as it is one of the materials currently under study for making extremely large telescope (ELT) segmented mirrors such as in the E-ELT project. The grinding experiments have been conducted on the BoX(R) grinding machine using wheels with grit sizes of 76 μm, 46 µm and 25 μm. The highest material removal rate (187.5 mm3/s) used ensures that a 1 metre diameter optic can be ground in less than 10 hours. The surface roughness and surface profile were measured using a Form Talysurf. The subsurface damage was revealed using a sub aperture polishing process in combination with an etching technique on small parts. These results are compared with the targeted form accuracy of 1 μm p-v over a 1 metre part, surface roughness of 50-150 nm RMS and subsurface damage in the range of 2-5 μm. This process stage was validated on a 1 metre hexagonal Zerodur(R) part.

  14. Preparation of anti-adhesion surfaces on aluminium substrates of rubber plastic moulds using a coupling method of liquid plasma and electrochemical machining

    Directory of Open Access Journals (Sweden)

    Jianbing Meng

    2014-02-01

    Full Text Available Hard anti-adhesion surfaces, with low roughness and wear resistance, on aluminium substrates of rubber plastic moulds were fabricated via a new coupling method of liquid plasma and electrochemical machining. With the aid of liquid plasma thermal polishing and electrochemical anodic dissolution, micro/nano-scale binary structures were prepared as the base of the anti-adhesion surfaces. The anti-adhesion behaviours of the resulting aluminium surfaces were analysed by a surface roughness measuring instrument, a scanning electron microscope (SEM, a Fourier-transform infrared spectrophotometer (FTIR, an X-ray diffractometer (XRD, an optical contact angle meter, a digital Vickers micro-hardness (Hv tester, and electronic universal testing. The results show that, after the liquid plasma and electrochemical machining, micro/nano-scale binary structures composed of micro-scale pits and nano-scale elongated boss structures were present on the sample surfaces. As a result, the anti-adhesion surfaces fabricated by the above coupling method have good anti-adhesion properties, better wear resistance and lower roughness.

  15. Research on the influence of machining introduced sub-surface defects and residue stress upon the mechanical properties of single crystal copper

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Large scale molecular dynamics simulations of nanomachining and stretching of single crystal copper are performed to analyze the machining process’ influence on the material’s mechanical properties. The simulation results show that the machining process will introduce interfacial defects inside the specimen and enhance the compressive stress beneath the surface. Gener- ally speaking, interfacial defects lead to the decrease of the strength limit, while residue compressive stress can enhance the elastic limit and even the strength limit. Various machining parameters are adopted to investigate their influence on the me- chanical behavior of machined specimen. Lower cutting speed and smaller cutting depth lead to less defects and greater residue compressive stress, which brings about better mechanical properties. The elastic limit increases by 36.8% under the cutting depth of 0.73 nm and decreases by 21.1% under the cutting depth of 1.46 nm. The strength limit increases by 7.7% under the cutting speed of 100 m/s and decreases by 28.2% under the cutting speed of 300 m/s.

  16. Transient, three-dimensional heat transfer model for the laser assisted machining of silicon nitride: 1. Comparison of predictions with measured surface temperature histories

    Energy Technology Data Exchange (ETDEWEB)

    Rozzi, J.C.; Pfefferkorn, F.E.; Shin, Y.C. [Purdue University, (United States). Laser Assisted Materials Processing Laboratory, School of Mechanical Engineering; Incropera, F.P. [University of Notre Dame, (United States). Aerospace and Mechanical Engineering Department

    2000-04-01

    Laser assisted machining (LAM), in which the material is locally heated by an intense laser source prior to material removal, provides an alternative machining process with the potential to yield higher material removal rates, as well as improved control of workpiece properties and geometry, for difficult-to-machine materials such as structural ceramics. To assess the feasibility of the LAM process and to obtain an improved understanding of governing physical phenomena, experiments have been performed to determine the thermal response of a rotating silicon nitride workpiece undergoing heating by a translating CO{sub 2} laser and material removal by a cutting tool. Using a focused laser pyrometer, surface temperature histories were measured to determine the effect of the rotational and translational speeds, the depth of cut, the laser-tool lead distance, and the laser beam diameter and power on thermal conditions. The measurements are in excellent agreement with predictions based on a transient, three-dimensional numerical solution of the heating and material removal processes. The temperature distribution within the unmachined workpiece is most strongly influenced by the laser power and laser-tool lead distance, as well as by the laser/tool translational velocity. A minimum allowable operating temperature in the material removal region corresponds to the YSiAlON glass transition temperature, below which tool fracture may occur. In a companion paper, the numerical model is used to further elucidate thermal conditions associated with laser assisted machining. (author)

  17. Application of response surface methodology on investigating flank wear in machining hardened steel using PVD TiN coated mixed ceramic insert

    Directory of Open Access Journals (Sweden)

    Ashok Kumar Sahoo

    2013-10-01

    Full Text Available The paper presents the development of flank wear model in turning hardened EN 24 steel with PVD TiN coated mixed ceramic insert under dry environment. The paper also investigates the effect of process parameter on flank wear (VBc. The experiments have been conducted using three level full factorial design techniques. The machinability model has been developed in terms of cutting speed (v, feed (f and machining time (t as input variable using response surface methodology. The adequacy of model has been checked using correlation coefficients. As the determination coefficient, R2 (98% is higher for the model developed; the better is the response model fits the actual data. In addition, residuals of the normal probability plot lie reasonably close to a straight line showing that the terms mentioned in the model are statistically significant. The predicted flank wear has been found to lie close to the experimental value. This indicates that the developed model can be effectively used to predict the flank wear in the hard turning. Abrasion and diffusion has been found to be the dominant wear mechanism in machining hardened steel from SEM micrographs at highest parametric range. Machining time has been found to be the most significant parameter on flank wear followed by cutting speed and feed as observed from main effect plot and ANOVA study.

  18. Quality factor due to roughness scattering of shear horizontal surface acoustic waves in nanoresonators

    NARCIS (Netherlands)

    Palasantzas, G.

    2008-01-01

    In this work we study the quality factor associated with dissipation due to scattering of shear horizontal surface acoustic waves by random self-affine roughness. It is shown that the quality factor is strongly influenced by both the surface roughness exponent H and the roughness amplitude w to late

  19. High quality crystalline silicon surface passivation by combined intrinsic and n-type hydrogenated amorphous silicon

    NARCIS (Netherlands)

    Schuttauf, J.A.; van der Werf, C.H.M.; Kielen, I.M.; van Sark, W.G.J.H.M.; Rath, J.K.

    2011-01-01

    We investigate the influence of thermal annealing on the passivation quality of crystalline silicon (c-Si) surfaces by intrinsic and n-type hydrogenated amorphous silicon (a-Si:H) films. For temperatures up to 255 C, we find an increase in surface passivation quality, corresponding to a decreased da

  20. To the question of formation the quality management system of activity on the example of machine-building enterprises of the Vinnytsia region

    Directory of Open Access Journals (Sweden)

    M.V. Balzan

    2016-04-01

    Full Text Available On the example of machine-building enterprises of Vinnytsia region the character and features of their activities are analyzed, as well as conclusions regarding instability and inefficiency of the work effectiveness. Analysis and grouping of enterprises on selected attributes made possible to clarify the nature of the major economic and business indicators in each group, which facilitated the study of relations between the general management systems and content of quality management systems of activity at enterprises and confirmed the direct interdependence between the content and efficiency of these management systems, the efficiency of the quality management and the state of enterprises. The list of indicators of the quality management system of activity is proposed. For each of them number of quality indicators, which are affected by the form (way quality management of activity, is formed. The relationship of indicators of quality management system with the classification features that allows to create a profile of the quality management system is realized in a table. It is concluded about the possibility of using the proposed classification system as an intellectual component of the program decision making support in the formation of the profile of the quality management system of activity.

  1. High quality broadband spatial reflections of slow Rayleigh surface acoustic waves modulated by a graded grooved surface

    KAUST Repository

    Xu, Yanlong

    2015-01-21

    We report high quality broadband spatial reflections of Rayleigh surface acoustic waves (SAWs) through a graded grooved surface. High quality means that no wave is allowed to transmit and the incident wave is nearly all reflected to the input side. The graded grooved surface is structured by drilling one dimensional array of graded grooves with increased depths on a flat surface. We investigate SAW dispersion relations, wave field distribution at several typical SAW wavelengths, and time evolution of a Gaussian pulse through the graded grooved surface. Results show that the input broadband Rayleigh SAWs can be slowed, spatially enhanced and stopped, and finally reflected to the input side. The study suggests that engraving the flat surface can be used as an efficient and economical way to manipulate Rayleigh SAWs, which has potential application in novel SAW devices such as filters, reflectors, sensors, energy harvesters, and diodes.

  2. 高质量绿色环保的精车切削优化%Optimization of finish turning for high quality in modern green manufacturing machining

    Institute of Scientific and Technical Information of China (English)

    胡成龙

    2014-01-01

    The cutting parameters optimization of green manufacturing machining is very important for machining quality ,machi-ning economics and profit .Subject to various practical cutting constraints ,a dual-objective optimization model for finish turning cutting,based on the minimum cutting energy and the minimum machining precision ,is proposed.The Non-dominated Sorting Genetic Algorithm-II(NSGA-II) and Multi-Objective Particle Swarm Optimization (MOPSO) are applied to the dual-objective nonlinear constrained optimization finish turning cutting model .Simulation results indicate that the Pareto-optimal solutions set by using NSGA-II algorithm are obtained more complete than the Pareto-optimal solutions set by applying the MOPSO algorithm .Un-der certain depth of cut ,the Pareto-optimal front for the cutting energy and machining precision can be fitted by the cubic polyno -mials equation and the fitting relevant index is equal to 0.9999.Under the Pareto-optimal front,the machining precision and feed rates can be also fitted by the quadratic polynomials equation and the fitting relevant index is equal to 0.99999,which provides practical guides for optimization of machining parameters .%绿色制造中的切削参数优化对于提高加工质量、加工成本、产品利润和节能环保具有非常重要的意义。考虑实际加工约束条件,建立了加工精度与切削能量的双目标精车切削优化模型。通过实例运用NSGA-II算法与MOPSO算法对精车优化切削模型进行仿真,结果表明,NSGA-II算法获得了更优的Pareto最优解集。在给定加工余量条件下,加工精度与切削能量的Pareto最优前沿可由三次曲线方程拟合,且拟合相关指数为0.9999。在加工精度与切削能量的Pareto最优解集下,加工精度和进给量的关系可由二次曲线方程拟合,且拟合相关指数为0.99999,为精车切削参数优化选择提供了实践指导。

  3. The Impact of Impervious Surface on Water Quality and Its Threshold in Korea

    Directory of Open Access Journals (Sweden)

    Hakkwan Kim

    2016-03-01

    Full Text Available The change in the impervious-pervious balance has significantly altered the stream water quality, and thus the threshold of the impervious surface area in the watershed has been an active research topic for many years. The objective of this study is to verify the correlation between impervious surfaces and water quality and to determine the threshold of the percentage of the impervious surface area (PISA for diagnosing the severity of future stream water quality problems in the watershed as well as regulating the PISA in Korea. Statistical results indicated that the PISA is a suitable indicator of water quality at the watershed scale and can illustrate the water quality problems caused by the impervious surface. In addition, the results from this study suggest that controlling the PISA within about 10% in watersheds is a fundamental strategy to mitigate the degradation of water quality.

  4. A Real-time NURBS Surface Interpolator for 5-axis Surface Machining%一个面向5轴曲面加工的实时NURBS曲面插补器

    Institute of Scientific and Technical Information of China (English)

    王永章; 陈良骥

    2005-01-01

    提出了一个实时非均匀有理B样条(NURBS)曲面插补器,论述了5轴平头刀加工方法.运用Taylor展开和坐标变换方法分别推导并实现了NURBS插补、刀具有效加工半径、刀具补偿以及逆运动变换等算法.与传统自由曲面加工不同的是,所提出的插补器能根据刀触点进给率而非刀位点进给率实时生成计算机数控(CNC)机床运动指令.对实例零件曲面进行演示与仿真分析,结果表明该曲面插补器可以应用于5轴曲面加工中.%A real-time non-uniform rational B-spline (NURBS) surface interpolator is proposed and 5-axis machining method with a flat-end cutter is discussed. With the Taylor expansion and the coordinate transformation, the algorithms of NURBS interpolation, cutter effective machining radius, cutter offsetting and inverse kinematics are deduced and implemented, respectively. Different from the conventional free-form surface machining, the proposed interpolator can real-time generate the motion commands of computer numerical control (CNC) machines with CC feedrate, rather than that of CL. An example part surface is demonstrated and the results of simulation show that the proposed method can be applied in actual 5-axis surface machining.

  5. Micro-machining.

    Science.gov (United States)

    Brinksmeier, Ekkard; Preuss, Werner

    2012-08-28

    Manipulating bulk material at the atomic level is considered to be the domain of physics, chemistry and nanotechnology. However, precision engineering, especially micro-machining, has become a powerful tool for controlling the surface properties and sub-surface integrity of the optical, electronic and mechanical functional parts in a regime where continuum mechanics is left behind and the quantum nature of matter comes into play. The surprising subtlety of micro-machining results from the extraordinary precision of tools, machines and controls expanding into the nanometre range-a hundred times more precise than the wavelength of light. In this paper, we will outline the development of precision engineering, highlight modern achievements of ultra-precision machining and discuss the necessity of a deeper physical understanding of micro-machining.

  6. THE QUALITY OF THE SURFACE AT THE BEECH WOODTURNING

    Directory of Open Access Journals (Sweden)

    Mirela CHERCIU

    2015-05-01

    Full Text Available There have been experiments made with outside cylindrical beech woodturning with low cutting speed, and feed successively changed. We study, qualitative rather than quantitative, the roughnesss of the surface achieved. It interprets the appearance of each surface based on the theory of cutting considerations. Resulted surface images are given, photographed with a camera and microscope. It appears that here are no propellers generated by the cutting tool nose on the cylindrical part, excepting the situation of using high feeds.

  7. A Study of the Surface Quality of High Purity Copper after Heat Treatment

    CERN Document Server

    Aicheler, M; Atieh, S; Calatroni, S; Riddone, G; Lebet, S; Samoshkin, A

    2011-01-01

    Themanufacturing flow of accelerating structures for the compact linear collider, based on diamond-machined high purity copper components, include several thermal cycles (diffusion bonding, brazing of cooling circuits, baking in vacuum, etc.). The high temperature cycles may be carried out following different schedules and environments (vacuum, reducing hydrogen atmosphere, argon, etc.) and develop peculiar surface topographies which have been the object of extended observations. This study presents and discusses the results of scanning electron microscopy (SEM) and optical microscopy investigations.

  8. Prebond Inspection Techniques to Improve the Quality of Adhesive Bonding Surface Treatments

    Science.gov (United States)

    2006-09-01

    when the measurement height was greater than 0.3 mm. Measurements of the surface cleanliness of the aluminium surface after abrasion, grit- blasting...Measurements to assess the homogeneity of the surface cleanliness were performed with a specially designed X-Y scanning unit and associated control...tape removed + + A. B. C. D. Grit-blasted plate DSTO-TR-1919 6 2.2 Surface Quality Measurements The surface cleanliness of the

  9. Surface topography analysis for dimensional quality control of replication at the micrometre scale

    DEFF Research Database (Denmark)

    Balcon, M.; Marinello, F.; Tosello, Guido;

    2011-01-01

    Replication of geometrical features and surfaces are present at different production levels, from realization of moulds to final product. Geometrical features must be reproduced within specification limits, to ensure product functionality . In order to control the replication quality, mould...... and replica surfaces must be quantitatively analysed and compared. In the present work, reference simulated surfaces were considered and studied in order to evaluate the effectiveness and traceability of different analysis tools for replication quality control. Topographies were analysed simulating different...

  10. Floating Vegetated Mats For Improving Surface Water Quality

    Science.gov (United States)

    Contamination of surface and ground waters is an environmental concern. Pollution from both point and nonpoint sources can render water unsuitable for use. Surface waters of concern include streams, rivers, ponds, lakes, canals, and wastewater lagoons. Lagooned wastewater from confined animal feedi...

  11. Assessing the quality of proton PBS treatment delivery using machine log files: comprehensive analysis of clinical treatments delivered at PSI Gantry 2.

    Science.gov (United States)

    Scandurra, D; Albertini, F; van der Meer, R; Meier, G; Weber, D C; Bolsi, A; Lomax, A

    2016-02-01

    Pencil beam scanning (PBS) proton therapy requires the delivery of many thousand proton beams, each modulated for position, energy and monitor units, to provide a highly conformal patient treatment. The quality of the treatment is dependent on the delivery accuracy of each beam and at each fraction. In this work we describe the use of treatment log files, which are a record of the machine parameters for a given field delivery on a given fraction, to investigate the integrity of treatment delivery compared to the nominal planned dose. The dosimetry-relevant log file parameters are used to reconstruct the 3D dose distribution on the patient anatomy, using a TPS-independent dose calculation system. The analysis was performed for patients treated at Paul Scherrer Institute on Gantry 2, both for individual fields and per series (or plan), and delivery quality was assessed by determining the percentage of voxels in the log file dose distribution within  +/-  1% of the nominal dose. It was seen that, for all series delivered, the mean pass rate is 96.4%. Furthermore, this work establishes a correlation between the delivery quality of a field and the beam position accuracy. This correlation is evident for all delivered fields regardless of individual patient or plan characteristics. We have also detailed further usefulness of log file analysis within our clinical workflow. In summary, we have highlighted that the integrity of PBS treatment delivery is dependent on daily machine performance and is specifically highly correlated with the accuracy of beam position. We believe this information will be useful for driving machine performance improvements in the PBS field.

  12. Assessing the quality of proton PBS treatment delivery using machine log files: comprehensive analysis of clinical treatments delivered at PSI Gantry 2

    Science.gov (United States)

    Scandurra, D.; Albertini, F.; van der Meer, R.; Meier, G.; Weber, D. C.; Bolsi, A.; Lomax, A.

    2016-02-01

    Pencil beam scanning (PBS) proton therapy requires the delivery of many thousand proton beams, each modulated for position, energy and monitor units, to provide a highly conformal patient treatment. The quality of the treatment is dependent on the delivery accuracy of each beam and at each fraction. In this work we describe the use of treatment log files, which are a record of the machine parameters for a given field delivery on a given fraction, to investigate the integrity of treatment delivery compared to the nominal planned dose. The dosimetry-relevant log file parameters are used to reconstruct the 3D dose distribution on the patient anatomy, using a TPS-independent dose calculation system. The analysis was performed for patients treated at Paul Scherrer Institute on Gantry 2, both for individual fields and per series (or plan), and delivery quality was assessed by determining the percentage of voxels in the log file dose distribution within  +/-  1% of the nominal dose. It was seen that, for all series delivered, the mean pass rate is 96.4%. Furthermore, this work establishes a correlation between the delivery quality of a field and the beam position accuracy. This correlation is evident for all delivered fields regardless of individual patient or plan characteristics. We have also detailed further usefulness of log file analysis within our clinical workflow. In summary, we have highlighted that the integrity of PBS treatment delivery is dependent on daily machine performance and is specifically highly correlated with the accuracy of beam position. We believe this information will be useful for driving machine performance improvements in the PBS field.

  13. Loss Prediction and Thermal Analysis of Surface-Mounted Brushless AC PM Machines for Electric Vehicle Application Considering Driving Duty Cycle

    Directory of Open Access Journals (Sweden)

    Tianxun Chen

    2016-01-01

    Full Text Available This paper presents a computationally efficient loss prediction procedure and thermal analysis of surface-mounted brushless AC permanent magnet (PM machine considering the UDDS driving duty cycle by using a lumped parameters’ thermal model. The accurate prediction of loss and its variation with load are essential for thermal analysis. Employing finite element analysis (FEA to determine loss at every load point would be computationally intensive. Here, the finite element analysis and/or experiment based computationally efficient winding copper and iron loss and permanent magnet (PM power loss models are employed to calculate the electromagnetic loss at every operation point, respectively. Then, the lumped parameter thermal method is used to analyse the thermal behaviour of the driving PM machine. Experiments have been carried out to measure the temperature distribution in a motor prototype. The calculation and experiment results are compared and discussed.

  14. Evaluation of the Technical-Economic Potential of Particle- Reinforced Aluminum Matrix Composites and Electrochemical Machining

    Science.gov (United States)

    Schubert, A.; Götze, U.; Hackert-Oschätzchen, M.; Lehnert, N.; Herold, F.; Meichsner, G.; Schmidt, A.

    2016-03-01

    Compared to conventional cutting, the processing of materials by electrochemical machining offers some technical advantages like high surface quality, no thermal or mechanical impact on the work piece and preservation of the microstructure of the work piece material. From the economic point of view, the possibility of process parallelization and the absence of any process-related tool wear are mentionable advantages of electrochemical machining. In this study, based on experimental results, it will be evaluated to what extent the electrochemical machining is technically and economically suitable for the finish-machining of particle- reinforced aluminum matrix composites (AMCs). Initial studies showed that electrochemical machining - in contrast to other machining processes - has the potential to fulfil demanding requirements regarding precision and surface quality of products or components especially when applied to AMCs. In addition, the investigations show that processing of AMCs by electrochemical machining requires less energy than the electrochemical machining of stainless steel. Therefore, an evaluation of electrochemically machined AMCs - compared to stainless steel - from a technical and an economic perspective will be presented in this paper. The results show the potential of electro-chemically machined AMCs and contribute to the enhancement of instruments for technical-economic evaluations as well as a comprehensive innovation control.

  15. Research on the thermal load of CNC milling machine

    Science.gov (United States)

    Nie, Xue-Jun; Wu, Ping-Dong

    2011-05-01

    Machine tool accuracy is the assurance of top-quality products in machining processes. In the all kinds of errors related to machine tools, thermal errors of machine tools' parts play an important role in machining accuracy and directly influence both the surface finish and the geometric shape of the finished workpiece. Therefore the objective of this work was to analyze the temperature field and thermal deformation in some parts of CNC machine tools. In this paper, the thermal boundary condition of main spindle and driving ball screw in CNC milling machine are discussed, some parameters in heat transfer process are calculated. Based on steady heat transfer process, the thermal analysis about spindle and ball screw is carried out under ANSYS environment, and their temperature fields are obtained when milling machine is working. Then the deformations of main spindle and ball screw are acquired by applying the thermal structure coupling element. Furthermore, in order to decrease main parts' deformations and improve the accuracy of CNC milling machine, some suggests are proposed.

  16. Development of a Parching Machine Using Super-Heated Vapor or Super-Heated High-Moisture Atmosphere

    Science.gov (United States)

    Sato, Shoichi; Shinsho, Seiji; Iriki, Hiroyuki; Asai, Junya; Suganuma, Hirofumi; Shibata, Tsutomu

    We developed a new parching machine with super-heated vapor or super-heated highmoisture atmosphere as a heat medium, and investigated the influence exerted on the characteristics of manufactured tea and crude tea quality. (1)We developed machine specifications that improved throughput and allowed us to control stable quality compared with the conventional kamairicha parching machine. (2)The new parching machine could not only manufacture like kamairicha but also achieve various degrees of steaming of products like green tea or heavily steamed sencha. (3)The new parching machine could not only deactivate enzymes but dry leaves. (4)The influence of throughput was great with respect to the grade of pan-parched flavour, which meant that there was a contact opportunity for tea leaves and the surface of machine's wall. (5)Unpleasant smells such as that produced in a summer crop of tea were reduced by the new parching machine.

  17. Machinability evaluation of machinable ceramics with fuzzy theory

    Institute of Scientific and Technical Information of China (English)

    YU Ai-bing; ZHONG Li-jun; TAN Ye-fa

    2005-01-01

    The property parameters and machining output parameters were selected for machinability evaluation of machinable ceramics. Based on fuzzy evaluation theory, two-stage fuzzy evaluation approach was applied to consider these parameters. Two-stage fuzzy comprehensive evaluation model was proposed to evaluate machinability of machinable ceramic materials. Ce-ZrO2/CePO4 composites were fabricated and machined for evaluation of machinable ceramics. Material removal rates and specific normal grinding forces were measured. The parameters concerned with machinability were selected as alternative set. Five grades were chosen for the machinability evaluation of machnable ceramics. Machinability grades of machinable ceramics were determined through fuzzy operation. Ductile marks are observed on Ce-ZrO2/CePO4 machined surface. Five prepared Ce-ZrO2/CePO4 composites are classified as three machinability grades according to the fuzzy comprehensive evaluation results. The machinability grades of Ce-ZrO2/CePO4 composites are concerned with CePO4 content.

  18. Analysis of thin-walled parts CNC machining process quality improvement%薄壁零件数控加工工艺质量改进分析

    Institute of Scientific and Technical Information of China (English)

    李盼

    2013-01-01

    计算机技术和仿真技术的迅猛发展推动着薄壁零件数控加工工艺由不成熟的工艺发展蜕变为工程科学。在此过程中,薄壁零件数控加工技术研究由传统的经验研究转变为科学的“定量分析”。薄壁零件存在的问题是刚性差、结构较复杂,在数控加工中易变形且难以控制,加工质量得不到切实保障。对目前的加工系统而言,数据加工过程可以分为三大步:一是加工前的工艺设计和离线零件编程,二是在加工过程中的在线加工和监控,三是加工后的检验处理。只有将三大步骤紧密结合协调统一好,才能确保工艺加工质量。但是,在线加工工艺系统会受到诸多因素的干扰,比如刀具变形、受热变形等,这些外在因素会严重影响质量。薄壁零件数控加工工艺在工业中的应用越来越广泛,保障加工工艺质量是当前急需关注和强调的问题。本文通过分析加工工艺的影响因素,提出改进装夹方案、修改切削参数、修正刀具路径、局部调整进给量等几种策略,来对加工路径和方式进行分析和优化,达到改进加工工艺质量的目的。%The rapid development of computer technology and simulation technology are pushing the thin-walled parts CNC machining process by the process of transformation of immature development of Engineering science. In this process, the processing technology of the thin wall parts CNC experience traditional research into scientific quantitative analysis "". Thin wall parts there is the problem of poor rigidity, structure is complex, in NC machining deformation and difficult to control, the processing quality can not be guaranteed. The processing system at present, the data processing process can be divided into three steps: one is the processing of process design and the offline part programming, two is the online processing and monitoring in machining process, three is

  19. Simulation of the «COSMONAUT-ROBOT» System Interaction on the Lunar Surface Based on Methods of Machine Vision and Computer Graphics

    Science.gov (United States)

    Kryuchkov, B. I.; Usov, V. M.; Chertopolokhov, V. A.; Ronzhin, A. L.; Karpov, A. A.

    2017-05-01

    Extravehicular activity (EVA) on the lunar surface, necessary for the future exploration of the Moon, involves extensive use of robots. One of the factors of safe EVA is a proper interaction between cosmonauts and robots in extreme environments. This requires a simple and natural man-machine interface, e.g. multimodal contactless interface based on recognition of gestures and cosmonaut's poses. When travelling in the "Follow Me" mode (master/slave), a robot uses onboard tools for tracking cosmonaut's position and movements, and on the basis of these data builds its itinerary. The interaction in the system "cosmonaut-robot" on the lunar surface is significantly different from that on the Earth surface. For example, a man, dressed in a space suit, has limited fine motor skills. In addition, EVA is quite tiring for the cosmonauts, and a tired human being less accurately performs movements and often makes mistakes. All this leads to new requirements for the convenient use of the man-machine interface designed for EVA. To improve the reliability and stability of human-robot communication it is necessary to provide options for duplicating commands at the task stages and gesture recognition. New tools and techniques for space missions must be examined at the first stage of works in laboratory conditions, and then in field tests (proof tests at the site of application). The article analyzes the methods of detection and tracking of movements and gesture recognition of the cosmonaut during EVA, which can be used for the design of human-machine interface. A scenario for testing these methods by constructing a virtual environment simulating EVA on the lunar surface is proposed. Simulation involves environment visualization and modeling of the use of the "vision" of the robot to track a moving cosmonaut dressed in a spacesuit.

  20. Machinability studies on INCONEL 718

    Science.gov (United States)

    Xavior, M. Anthony; Patil, Mahesh; Maiti, Abheek; Raj, Mrinal; Lohia, Nitesh

    2016-09-01

    The main objective of proposed work is to determine the influence of controllable parameters on machining characteristics of Inconel-718 and to achieve the optimum parameters for sustainable and efficient turning. Understanding the consequences of advanced tool materials together with higher cutting speeds on the formation of residual stresses and therefore the underlying mechanisms of small structural alteration within the subterranean layer thereby becomes terribly crucial for predicting product quality and more optimizing the machining conditions. Controllable cutting parameters such as cutting velocity, feed rate and depth of cut were selected at different level for experimentations in accordance with the Taguchi L9 array method using Minimum Quantity Lubrication (MQL) cutting condition and three different tools namely PVD TiAlN carbide, Cubic boron nitride and ceramic. Extensive study is done on the resulting surface roughness, surface subsurface hardness, tool wear and chip morphology. The results obtained from each of the tool were thoroughly analyzed and finally the optimized parameters are obtained for efficient machining of Inconel 718.

  1. Identification of machining defects by Small Displacement Torsor and form parameterization method

    CERN Document Server

    Sergent, Alain; Favreliere, Hugues; Duret, Daniel; Samper, Serge; Villeneuve, François

    2011-01-01

    In the context of product quality, the methods that can be used to estimate machining defects and predict causes of these defects are one of the important factors of a manufacturing process. The two approaches that are presented in this article are used to determine the machining defects. The first approach uses the Small Displacement Torsor (SDT) concept [BM] to determine displacement dispersions (translations and rotations) of machined surfaces. The second one, which takes into account form errors of machined surface (i.e. twist, comber, undulation), uses a geometrical model based on the modal shape's properties, namely the form parameterization method [FS1]. A case study is then carried out to analyze the machining defects of a batch of machined parts.

  2. Study on Effect of Ultrasonic Vibration on Grinding Force and Surface Quality in Ultrasonic Assisted Micro End Grinding of Silica Glass

    Directory of Open Access Journals (Sweden)

    Zhang Jianhua

    2014-01-01

    Full Text Available Ultrasonic vibration assisted micro end grinding (UAMEG is a promising processing method for micro parts made of hard and brittle materials. First, the influence of ultrasonic assistance on the mechanism of this processing technology is theoretically analyzed. Then, in order to reveal the effects of ultrasonic vibration and grinding parameters on grinding forces and surface quality, contrast grinding tests of silica glass with and without ultrasonic assistance using micro radial electroplated diamond wheel are conducted. The grinding forces are measured using a three-component dynamometer. The surface characteristics are detected using the scanning electron microscope. The experiment results demonstrate that grinding forces are significantly reduced by introducing ultrasonic vibration into conventional micro end grinding (CMEG of silica glass; ultrasonic assistance causes inhibiting effect on variation percentages of tangential grinding force with grinding parameters; ductile machining is easier to be achieved and surface quality is obviously improved due to ultrasonic assistance in UAMEG. Therefore, larger grinding depth and feed rate adopted in UAMEG can lead to the improvement of removal rate and machining efficiency compared with CMEG.

  3. An evaluation of the machinability of nitinol shape memory alloy by electrochemical polishing

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Eun Sang; Shin, Tae Hee [Inha University, Incheon (Korea, Republic of)

    2011-04-15

    Nitinol, a shape memory alloy (SMA), is manufactured from titanium and nickel, and is employed in various fields for use in devices such as micro sensors, ultra-precision devices and satellite wings. It is also highly recommended as a material in medical stents for insertion into the human body because it has excellent organic compatibility. However, because they are intended to be inserted into the human body, products such as medical stents require a high-quality surface. Because nitinol has more of the characteristics of titanium than of nickel, one of its drawbacks is that heat generated in nitinol during machining is not discharged smoothly and inner stress occurs when traditional machining methods are used. To overcome this difficulty, various non-traditional machining methods, including non-contact machining, have been investigated for use with nitinol. To further explore non-traditional machining methods that may be appropriate for use with nitinol, this study investigates the application of electrochemical polishing to the machining of nitinol. Characteristics of the electrochemical polishing (EP), a representative non-traditional machining, for nitinol SMA are studied. Nitinol SMA of the EP machining parameters such as electrolyte composition, applied current, machining time and inter electrode gap (IEG) are researched and the machined surface state is analyzed according to each parameters parameter. So, the most suitable EP machining conditions for nitinol SMA are derived.

  4. Some Key Technologies of a New-type CNC Curve Grinding Machine

    Institute of Scientific and Technical Information of China (English)

    WU Qi; HU De-jin

    2007-01-01

    This paper presented a new-type CNC curve grinding machine, in order to conquer the disadvantages of conventional NC curve grinding machine and improve surface quality, dimensional accuracy and machining efficiency. The new-type grinder adopts some high and new technologies:①the normal tracing device could make grinding wheel coincide with the normal direction of the machining points in work piece, and improve surface quality and dimensional accuracy;②the digital image on-line recognition system could monitor machining process and compensate wheel wear in real time;③linear motor drive mechanism could realize the exact adjustment of the grinding head digitally and increase the machining efficiency. The math models of normal tracing and circular tolerance zone were presented. The experimental results show that the new-type CNC curve grinding machine equipped with the three devices mentioned above is easy to realize the precision grinding of any complex curve, and improve surface quality, dimensional accuracy and machining efficiency.

  5. Scaled multisensor inspection of extended surfaces for industrial quality control

    Science.gov (United States)

    Kayser, Daniel; Bothe, Thorsten; Osten, Wolfgang

    2002-06-01

    Reliable real-time surface inspection of extended surfaces with high resolution is needed in several industrial applications. With respect to an efficient application to extended technical components such as aircraft or automotive parts, the inspection system has to perform a robust measurement with a ratio of less then 10-6 between depth resolution and lateral extension. This ratio is at least one order beyond the solutions that are offered by existing technologies. The concept of scaled topometry consists of arranging different optical measurement techniques with overlapping ranges of resolution systematically in order to receive characteristic surface information with the required accuracy. In such a surface inspection system, an active algorithm combines measurements on several scales of resolution and distinguishes between local fault indicating structures with different extensions and global geometric properties. The first part of this active algorithm finds indications of critical surface areas in the data of every measurement and separates them into different categories. The second part analyses the detected structures in the data with respect to their resolution and decides whether a further local measurement with a higher resolution has to be performed. The third part positions the sensors and starts the refined measurements. The fourth part finally integrates the measured local data set into the overall data mesh. We have constructed a laboratory setup capable of measuring surfaces with extensions up to 1500mm x 1000mm x 500mm (in x-, y- and z-direction respectively). Using this measurement system we will be able to separate the fault indicating structures on the surface from the global shape and to classify the detected structures according to their extensions and characteristic shapes simultaneously. The level of fault detection probability will be applicable by input parameter control.

  6. Quality of surface water in Missouri, water year 2012

    Science.gov (United States)

    Barr, Miya N.

    2014-01-01

    The U.S. Geological Survey, in cooperation with the Missouri Department of Natural Resources, designed and operates a series of monitoring stations on streams and springs throughout Missouri known as the Ambient Water-Quality Monitoring Network. During the 2012 water year (October 1, 2011, through September 30, 2012), data were collected at 81 stations—73 Ambient Water-Quality Monitoring Network stations, 6 alternate Ambient Water-Quality Monitoring Network stations, and 2 U.S. Geological Survey National Stream Quality Accounting Network stations. Dissolved oxygen, specific conductance, water temperature, suspended solids, suspended sediment, fecal coliform bacteria, Escherichia coli bacteria, dissolved nitrate plus nitrite as nitrogen, total phosphorus, dissolved and total recoverable lead and zinc, and select pesticide compound summaries are presented for 78 of these stations. The stations primarily have been classified into groups corresponding to the physiography of the State, primary land use, or unique station types. In addition, a summary of hydrologic conditions in the State including peak discharges, monthly mean discharges, and 7-day low flow is presented.

  7. Quality of surface water in Missouri, water year 2013

    Science.gov (United States)

    Barr, Miya N.; Schneider, Rachel E.

    2014-01-01

    The U.S. Geological Survey, in cooperation with the Missouri Department of Natural Resources, designed and operates a series of monitoring stations on streams and springs throughout Missouri known as the Ambient Water-Quality Monitoring Network. During the 2013 water year (October 1, 2012, through September 30, 2013), data were collected at 79 stations—73 Ambient Water-Quality Monitoring Network stations, 4 alternate Ambient Water-Quality Monitoring Network stations, and 2 U.S. Geological Survey National Stream Quality Accounting Network stations. Dissolved oxygen, specific conductance, water temperature, suspended solids, suspended sediment, Escherichia coli bacteria, fecal coliform bacteria, dissolved nitrate plus nitrite as nitrogen, total phosphorus, dissolved and total recoverable lead and zinc, and select pesticide compound summaries are presented for 76 of these stations. The stations primarily have been classified into groups corresponding to the physiography of the State, primary land use, or unique station types. In addition, a summary of hydrologic conditions in the State including peak discharges, monthly mean discharges, and 7-day low flow is presented.

  8. Machine Translation

    Institute of Scientific and Technical Information of China (English)

    张严心

    2015-01-01

    As a kind of ancillary translation tool, Machine Translation has been paid increasing attention to and received different kinds of study by a great deal of researchers and scholars for a long time. To know the definition of Machine Translation and to analyse its benefits and problems are significant for translators in order to make good use of Machine Translation, and helpful to develop and consummate Machine Translation Systems in the future.

  9. Improvement of Machinability of Mild Steel during Turning Operation by Magnetic Cutting

    Directory of Open Access Journals (Sweden)

    Anayet U. Patwari

    2012-01-01

    Full Text Available This paper presents the details of improvement of machinability of mild steel using magnetic cutting during turning operation. Improvement of machinability was evaluated in terms of tool life, surface roughness and chip morphology. Machine tool chatter is a type of intensive self-excited vibrations of individual components of Machine-Tool-Fixture-Work (MTFW system. Chatter causes unwanted excessive vibratory motion in between the tool and the work-piece causing adverse effects on the product quality and machine-tool and tool life. In addition to the damage of the work-piece surface due to chatter marks, the occurrence of severe chatter results in many adverse effects, which include poor dimensional accuracy of the work-piece, reduction of tool life, and damage to the machine. Chatter is formed as resonance phenomena during machining because of the instability of the closed-loop system formed by machine tool structure and metal-cutting process. In this study, magnets were used to avoid the chatter formation zone and its effect on machinability was investigated. Improvements in tool life and surface finish were observed during magnetic cutting of the mild steel. An obvious change in the chip behaviour was also present. These observations further enhance the possibility of using this magnetic cutting to eliminate the chatter formation zones and hence eliminate the adverse effect of chatter on machinability.

  10. Effects of laser ablation on cemented tungsten carbide surface quality

    Energy Technology Data Exchange (ETDEWEB)

    Tan, J.L.; Butler, D.L.; Sim, L.M.; Jarfors, A.E.W. [Singapore Institute of Manufacturing Technology, Singapore (Singapore)

    2010-11-15

    Although laser micromachining has been touted as being the most promising way to fabricate micro tools, there has been no proper evaluation of the effects of laser ablation on bulk material properties. The current work demonstrates the effects of laser ablation on the properties of a cemented tungsten carbide surface. Of particular interest is the resultant increase in compressive residual stresses in the ablated surface. From this study it is seen that there are no adverse effects from laser ablation of cemented tungsten carbide that would preclude its use for the fabrication of micro-tools but a finishing process may not be avoidable. (orig.)

  11. Effects of laser ablation on cemented tungsten carbide surface quality

    Science.gov (United States)

    Tan, J. L.; Butler, D. L.; Sim, L. M.; Jarfors, A. E. W.

    2010-11-01

    Although laser micromachining has been touted as being the most promising way to fabricate micro tools, there has been no proper evaluation of the effects of laser ablation on bulk material properties. The current work demonstrates the effects of laser ablation on the properties of a cemented tungsten carbide surface. Of particular interest is the resultant increase in compressive residual stresses in the ablated surface. From this study it is seen that there are no adverse effects from laser ablation of cemented tungsten carbide that would preclude its use for the fabrication of micro-tools but a finishing process may not be avoidable.

  12. Sustainable machining

    CERN Document Server

    2017-01-01

    This book provides an overview on current sustainable machining. Its chapters cover the concept in economic, social and environmental dimensions. It provides the reader with proper ways to handle several pollutants produced during the machining process. The book is useful on both undergraduate and postgraduate levels and it is of interest to all those working with manufacturing and machining technology.

  13. QUALITY ANALYSIS OF 3D SURFACE RECONSTRUCTION USING MULTI-PLATFORM PHOTOGRAMMETRIC SYSTEMS

    Directory of Open Access Journals (Sweden)

    Z. Lari

    2016-06-01

    Full Text Available In recent years, the necessity of accurate 3D surface reconstruction has been more pronounced for a wide range of mapping, modelling, and monitoring applications. The 3D data for satisfying the needs of these applications can be collected using different digital imaging systems. Among them, photogrammetric systems have recently received considerable attention due to significant improvements in digital imaging sensors, emergence of new mapping platforms, and development of innovative data processing techniques. To date, a variety of techniques haven been proposed for 3D surface reconstruction using imagery collected by multi-platform photogrammetric systems. However, these approaches suffer from the lack of a well-established quality control procedure which evaluates the quality of reconstructed 3D surfaces independent of the utilized reconstruction technique. Hence, this paper aims to introduce a new quality assessment platform for the evaluation of the 3D surface reconstruction using photogrammetric data. This quality control procedure is performed while considering the quality of input data, processing procedures, and photo-realistic 3D surface modelling. The feasibility of the proposed quality control procedure is finally verified by quality assessment of the 3D surface reconstruction using images from different photogrammetric systems.

  14. Fundamentals of machine design

    CERN Document Server

    Karaszewski, Waldemar

    2011-01-01

    A forum of researchers, educators and engineers involved in various aspects of Machine Design provided the inspiration for this collection of peer-reviewed papers. The resultant dissemination of the latest research results, and the exchange of views concerning the future research directions to be taken in this field will make the work of immense value to all those having an interest in the topics covered. The book reflects the cooperative efforts made in seeking out the best strategies for effecting improvements in the quality and the reliability of machines and machine parts and for extending

  15. Assessment of Water Quality of Runoff from Sealed Asphalt Surfaces

    Science.gov (United States)

    This report discusses the results of runoff tests from recently-sealed asphalt surfaces conducted at EPA's Urban Watershed Research Facility (UWRF) in Edison, New Jersey. Both bench-scale panels and full-scale test plots were evaluated. Full-scale tests were performed on an asp...

  16. Quality of surface water in Missouri, water year 2014

    Science.gov (United States)

    Barr, Miya N.

    2015-12-18

    The U.S. Geological Survey, in cooperation with the Missouri Department of Natural Resources, designed and operates a series of monitoring stations on streams and springs throughout Missouri known as the Ambient Water-Quality Monitoring Network. During the 2014 water year (October 1, 2013, through September 30, 2014), data were collected at 74 stations—72 Ambient Water-Quality Monitoring Network stations and 2 U.S. Geological Survey National Stream Quality Assessment Network stations. Dissolved oxygen, specific conductance, water temperature, suspended solids, suspended sediment, Escherichia coli bacteria, fecal coliform bacteria, dissolved nitrate plus nitrite as nitrogen, total phosphorus, dissolved and total recoverable lead and zinc, and select pesticide compound summaries are presented for 71 of these stations. The stations primarily have been classified into groups corresponding to the physiography of the State, primary land use, or unique station types. In addition, a summary of hydrologic conditions in the State including peak discharges, monthly mean discharges, and 7-day low flow is presented.

  17. Quality of surface water in Missouri, water year 2010

    Science.gov (United States)

    Barr, Miya N.

    2011-01-01

    The U.S. Geological Survey, in cooperation with the Missouri Department of Natural Resources, designs and operates a series of monitoring stations on streams throughout Missouri known as the Ambient Water-Quality Monitoring Network. During the 2010 water year (October 1, 2009 through September 30, 2010), data were collected at 75 stations-72 Ambient Water-Quality Monitoring Network stations, 2 U.S. Geological Survey National Stream Quality Accounting Network stations, and 1 spring sampled in cooperation with the U.S. Forest Service. Dissolved oxygen, specific conductance, water temperature, suspended solids, suspended sediment, fecal coliform bacteria, Escherichia coli bacteria, dissolved nitrate plus nitrite, total phosphorus, dissolved and total recoverable lead and zinc, and select pesticide compound summaries are presented for 72 of these stations. The stations primarily have been classified into groups corresponding to the physiography of the State, primary land use, or unique station types. In addition, a summary of hydrologic conditions in the State including peak discharges, monthly mean discharges, and 7-day low flow is presented.

  18. Quality of surface water in Missouri, water year 2009

    Science.gov (United States)

    Barr, Miya N.

    2010-01-01

    The U.S. Geological Survey, in cooperation with the Missouri Department of Natural Resources, designs and operates a series of monitoring stations on streams throughout Missouri known as the Ambient Water-Quality Monitoring Network. During the 2009 water year (October 1, 2008, through September 30, 2009), data were collected at 75 stations-69 Ambient Water-Quality Monitoring Network stations, 2 U.S. Geological Survey National Stream Quality Accounting Network stations, 1 spring sampled in cooperation with the U.S. Forest Service, and 3 stations sampled in cooperation with the Elk River Watershed Improvement Association. Dissolved oxygen, specific conductance, water temperature, suspended solids, suspended sediment, fecal coliform bacteria, Escherichia coli bacteria, dissolved nitrate plus nitrite, total phosphorus, dissolved and total recoverable lead and zinc, and select pesticide compound summaries are presented for 72 of these stations. The stations primarily have been classified into groups corresponding to the physiography of the State, primary land use, or unique station types. In addition, a summary of hydrologic conditions in the State including peak discharges, monthly mean discharges, and seven-day low flow is presented.

  19. Quality of surface water in Missouri, water year 2011

    Science.gov (United States)

    Barr, Miya N.

    2012-01-01

    The U.S. Geological Survey, in cooperation with the Missouri Department of Natural Resources, designed and operates a series of monitoring stations on streams throughout Missouri known as the Ambient Water-