WorldWideScience

Sample records for efficiency deep grinding

  1. Critical study of high efficiency deep grinding

    OpenAIRE

    Johnstone, lain

    2002-01-01

    The recent years, the aerospace industry in particular has embraced and actively pursued the development of stronger high performance materials, namely nickel based superalloys and hardwearing steels. This has resulted in a need for a more efficient method of machining, and this need was answered with the advent of High Efficiency Deep Grinding (HEDG). This relatively new process using Cubic Boron Nitride (CBN) electroplated grinding wheels has been investigated through experim...

  2. A critical study of high efficiency deep grinding

    International Nuclear Information System (INIS)

    Johnstone, Iain

    2002-01-01

    The recent years, the aerospace industry in particular has embraced and actively pursued the development of stronger high performance materials, namely nickel based superalloys and hardwearing steels. This has resulted in a need for a more efficient method of machining, and this need was answered with the advent of High Efficiency Deep Grinding (HEDG). This relatively new process using Cubic Boron Nitride (CBN) electroplated grinding wheels has been investigated through experimental and theoretical means applied to two widely used materials, M50 bearing steel and IN718 nickel based superalloy. It has been shown that this grinding method using a stiff grinding centre such as the Edgetek 5-axis machine is a viable process. Using a number of experimental designs, produced results which were analysed using a variety of methods including visual assessment, sub-surface microscopy and surface analysis using a Scanning Electron Microscope (SEM), residual stress measurement using X-Ray Diffraction (XRD) techniques, Barkhausen Noise Amplitude (BNA) measurements, surface roughness and Vickers micro-hardness appraisal. It has been shown that the fundamentals of the HEDG process have been understood through experimental as well as theoretical means and that through the various thermal models used, grinding temperatures can be predicted to give more control over this dynamic process. The main contributions to knowledge are made up of a number of elements within the grinding environment, the most important being the demonstration of the HEDG effect, explanation of the phenomenon and the ability to model the process. It has also been shown that grinding is a dynamic process and factors such as wheel wear will result in a continuous change in the optimum grinding conditions for a given material and wheel combination. With the significance of these factors recognised, they can be accounted for within an industrial adaptive control scenario with the process engineer confident of a

  3. Development of a Laser-Guided Deep-Hole Internal-Grinding Tool (Series 1) : Grinding Forces

    OpenAIRE

    Katsuki, Akio; Onikura, Hiromichi; Sajima, Takao; Park, Hyunkoo

    2005-01-01

    The laser-guided deep-hole internal grinding tool is developed to bore accurate and straight deep-holes with high surface quality. The tool consists of a grinding head, the front and rear actuators mounted on an actuator holder and a laser diode set in the back end of the holder. The grinding head consists of a diamond or CBN wheel, an air motor, and the piezoelectric actuators for the compensation of tool diameter. The grinding wheel is located eccentrically at the grinding head. The grindin...

  4. Eco-efficiency of grinding processes and systems

    CERN Document Server

    Winter, Marius

    2016-01-01

    This research monograph aims at presenting an integrated assessment approach to describe, model, evaluate and improve the eco-efficiency of existing and new grinding processes and systems. Various combinations of grinding process parameters and system configurations can be evaluated based on the eco-efficiency. The book presents the novel concept of empirical and physical modeling of technological, economic and environmental impact indicators. This includes the integrated evaluation of different grinding process and system scenarios. The book is a valuable read for research experts and practitioners in the field of eco-efficiency of manufacturing processes but the book may also be beneficial for graduate students.

  5. High Performance Grinding and Advanced Cutting Tools

    CERN Document Server

    Jackson, Mark J

    2013-01-01

    High Performance Grinding and Advanced Cutting Tools discusses the fundamentals and advances in high performance grinding processes, and provides a complete overview of newly-developing areas in the field. Topics covered are grinding tool formulation and structure, grinding wheel design and conditioning and applications using high performance grinding wheels. Also included are heat treatment strategies for grinding tools, using grinding tools for high speed applications, laser-based and diamond dressing techniques, high-efficiency deep grinding, VIPER grinding, and new grinding wheels.

  6. Grinding efficiency improvement of hydraulic cylinders parts for mining equipment

    Directory of Open Access Journals (Sweden)

    Korotkov Aleksandr

    2017-01-01

    Full Text Available The aim of the article is to find out ways to improve parts treatment and components of mining equipment on the example of hydraulic cylinders parts, used as pillars for mine roof supports, and other actuator mechanisms. In the course of the research work methods of machine retaining devices design were used, the scientific approaches for the selection of progressive grinding schemes were applied; theoretical and practical experience in the design and production of new constructions of grinding tools was used. As a result of this work it became possible to create a progressive construction of a machine retaining device for grinding of large parts of hydraulic cylinders, to apply an effective scheme of rotary abrasive treatment, to create and implement new design of grinding tools by means of grains with controllable shape and orientation. Implementation of the results obtained in practice will improve the quality and performance of repairing and manufacturing of mining equipment.

  7. Improving the plunge grinding technology efficiency through a rigid scheme use

    Directory of Open Access Journals (Sweden)

    І. О. Рябенков

    2016-07-01

    Full Text Available Theoretical bases of grinding technology researches results form the basis of this work. It has been shown that grinding efficiency increase can be achieved through the use of new kinematic grinding schemes and progressive designs of abrasive tools. However, not enough attention is paid to the calculation of the main technological machining parameters with due regard to separate processes of cutting and friction at grinding, thus restricting the effective application of these kinematic grinding schemes and scientifically grounded selection of optimal processing conditions. In this paper a mathematical model has been developed for determining the material removal rate and cutting force at plunge grinding, what made it possible to substantiate reducing the power strength at grinding and to increase productivity. Calculations revealed that the cutting force at plunge grinding is conditioned by the disk bond friction against the material being processed, the intensity of which in the course of processing time increases proportionally due to an increase of elastic movements in the technological system. Proceeding from these results the optimum grinding conditions based on the use of the abrasive disk that works under self-sharpening conditions, thus eliminating the disk bond friction against the material being processed, have been grounded. In this case, the abrasive disk provides complete removal of the processed material supplied to the cutting zone at the nominal speed of a workpiece movement. Also the ability to reduce cutting forces through the increase of the disk speed and the workpiece speed ratio has been shown

  8. Research of grinding process of gears with involute profile to increase its efficiency

    Science.gov (United States)

    Ivanova, T. N.; Korshunov, A. I.; Sannikov, I. N.; Tyukpiekov, V. N.

    2018-03-01

    Grinding as final processing exerts great influence on quality and accuracy of a surface layer of gears. Gear grinding is the most productive method of abrasive processing providing gears of 3 - 8 degrees of accuracy. However violation of the temperature condition of grinding leads to emergence of burns on the surfaces of gears. Therefore the research of the reasons generating defects and finding the ways of their elimination are relevant. The work presents the research of involute tooth profile grinding by wheels of different types with different ways to form a surface. For every way the movements of a tool and a workpiece in order to receive a contour of the tooth socket are simulated. The advantages and the shortcomings of the tooth grinding using form wheels in a grinding method and using dish, worm wheels in generating the grinding method are revealed. The experience of gear production shows that availability of burns in the certain part of a tooth profile is caused by features of the gear grinding process. Theoretical and experimental researches of the thermal phenomena of gear grinding with different configurations of spots in a contact zone and a trajectory of their movement are conducted. There are recommendations how to choose grinding modes, characteristics of abrasive tools taking into account a non-burnt condition of a working surface of a gear. The right choice of lubricating fluid and the way of its supply greatly affect the efficiency of the gear grinding process. It is established that lubricating fluid with special additives gives the best results to obtain desired roughness of a processed surface. The recommendations of effective fluids and their foreign analogs are made.

  9. Efficient Fuel Pretreatment: Simultaneous Torrefaction and Grinding of Biomass

    DEFF Research Database (Denmark)

    Saleh, Suriyati Binti; Hansen, Brian Brun; Jensen, Peter Arendt

    2013-01-01

    Combining torrefaction and grinding of biomass in one reactor may be an attractive fuel pretreatment process. A combined laboratory torrefaction and ball mill reactor has been constructed for studies of the influence of temperature and residence time on the product yields and particle size...... reductions of Danish wheat straw, spruce chips, and pine chips. On the basis of initial experiments, which evaluated the influence of reactor mass loading, gas flow, and grinding ball size and material, a standard experimental procedure was developed. The particle size reduction capability......, and ash composition, where straw has a higher alkali content. This and other studies indicate that the large difference in the alkali contents of the biomasses is the main cause for the observed difference in torrefaction characteristics. Experiments with separate particle heating and grinding showed...

  10. Grinding efficiency of abutment tooth with both dentin and core composite resin on axial plane.

    Science.gov (United States)

    Miho, Otoaki; Sato, Toru; Matsukubo, Takashi

    2015-01-01

    The purpose of this study was to evaluate grinding efficiency in abutment teeth comprising both dentin and core composite resin in the axial plane. Grinding was performed over 5 runs at two loads (0.5 or 0.25 N) and two feed rates (1 or 2 mm/sec). The grinding surface was observed with a 3-D laser microscope. Tomographic images of the grinding surfaces captured perpendicular to the feed direction were also analyzed. Using a non-ground surface as a reference, areas comprising only dentin, both dentin and core composite resin, or only core composite resin were analyzed to determine the angle of the grinding surface. Composite resins were subjected to the Vickers hardness test and scanning electron microscopy. Data were statistically analyzed using a one-way analysis of variance and multiple comparison tests. Multiple regression analysis was performed for load, feed rate, and Vickers hardness of the build-up material depending on number of runs. When grinding was performed at a constant load and feed rate, a greater grinding angle was observed in areas comprising both dentin and composite resin or only composite resin than in areas consisting of dentin alone. A correlation was found between machinability and load or feed rate in areas comprising both dentin and composite resin or composite resin alone, with a particularly high correlation being observed between machinability and load. These results suggest that great caution should be exercised in a clinical setting when the boundary between the dentin and composite resin is to be ground, as the angle of the grinding surface changes when the rotating diamond point begins grinding the composite resin.

  11. Cylindrical plunge grinding of difficult to grind materials

    International Nuclear Information System (INIS)

    Nakajima, Toshikatsu; Uno, Yoshiyuki; Kayahara, Masayuki.

    1983-01-01

    Cylindrical plunge grinding processes of titanium alloy and nickel-base superalloys with various kinds of conventional grinding wheels, which are known as difficult to grind materials, are experimentally investigated, analyzing size generation process, grinding force, surface roughness, wheel wear, grinding ratio and so on. For grinding titanium alloy Ti-6Al-4V, GC grinding wheel yields most superior grinding results which leads to lower grinding force, smaller residual stock, less wheel wear and higher grinding ratio up to about 3 with GC 80 L 9 V wheel. Then, for grinding nickelbase superalloys Waspaloy and Rene 41, WA 150 L 9 V wheel yields better grinding results in surface roughness, wheel wear, grinding ratio without chatter vibration though grinding force is higher, and the grinding ratio about 3 is obtained. Furthermore, higher plunge speed and speed ratio result in higher grinding efficiency though grinding force, surface roughness, wheel wear increase for grinding titanium alloy and nickel-base superalloys. (author)

  12. The Effect of the Wear of Rotor Pins on Grinding Efficiency in a High-speed Disintegrator

    OpenAIRE

    Karel DVOŘÁK; Dušan DOLÁK; David PALOUŠEK; Ladislav ČELKO; David JECH

    2018-01-01

    One of the directions intensively investigated in the field of milling is high-energy milling (HEM). One type of HEM is high-speed grinding in high-speed disintegrators. This type of mill is particularly suitable for the grinding and activation of fine powder materials. It has several advantages, such as a very intensive and continual refining process. One disadvantage is that its grinding pins are prone to abrasion, which may result in a decrease of the efficiency of grinding. This effect wa...

  13. THEORETICAL AND EXPERIMENTAL STUDIES OF ENERGY-EFFICIENT GRINDING PROCESS OF CEMENT CLINKER IN A BALL MILL

    Directory of Open Access Journals (Sweden)

    Kuznetsova M.M.

    2014-08-01

    Full Text Available The article presents results of theoretical and experimental research of grinding process of bulk materials in a ball mill. The new method of determination of energy efficiently mode of operation of ball mills in a process of a cement clinker grinding is proposed and experimentally tested.

  14. Effects of High Pressure ORE Grinding on the Efficiency of Flotation Operations

    Science.gov (United States)

    Saramak, Daniel; Krawczykowska, Aldona; Młynarczykowska, Anna

    2014-10-01

    This article discusses issues related to the impact of the high pressure comminution process on the efficiency of the copper ore flotation operations. HPGR technology improves the efficiency of mineral resource enrichment through a better liberation of useful components from waste rock as well as more efficient comminution of the material. Research programme included the run of a laboratory flotation process for HPGR crushing products at different levels of operating pressures and moisture content. The test results showed that products of the high-pressure grinding rolls achieved better recoveries in flotation processes and showed a higher grade of useful components in the flotation concentrate, in comparison to the ball mill products. Upgrading curves have also been marked in the following arrangement: the content of useful component in concentrate the floatation recovery. All upgrading curves for HPGR products had a more favourable course in comparison to the curves of conventionally grinded ore. The results also indicate that various values of flotation recoveries have been obtained depending on the machine operating parameters (i.e. the operating pressure), and selected feed properties (moisture).

  15. Effect of deep cryogenic treatment on the microstructure and wear performance of Cr-Mn-Cu white cast iron grinding media

    Science.gov (United States)

    Vidyarthi, M. K.; Ghose, A. K.; Chakrabarty, I.

    2013-12-01

    The phase transformation and grinding wear behavior of Cr-Mn-Cu white cast irons subjected to destabilization treatment followed by air cooling or deep cryogenic treatment were studied as a part of the development program of substitute alloys for existing costly wear resistant alloys. The microstructural evolution during heat treatment and the consequent improvement in grinding wear performance were evaluated with optical and scanning electron microscopy, X-ray diffraction analysis, bulk hardness, impact toughness and corrosion rate measurements, laboratory ball mill grinding wear test etc. The deep cryogenic treatment has a significant effect in minimizing the retained austenite content and converts it to martensite embedded with fine M7C3 alloy carbides. The cumulative wear losses in cryotreated alloys are lesser than those with conventionally destabilized alloys followed by air cooling both in wet and dry grinding conditions. The cryotreated Cr-Mn-Cu irons exhibit comparable wear performance to high chromium irons.

  16. Electrolytic In-process Dressing (ELID) for high-efficiency, precision grinding of ceramic parts: An experiment study

    Energy Technology Data Exchange (ETDEWEB)

    Bandyopadhyay, B.P.

    1995-08-01

    This report describes Electrolytic In-process Dressing (ELID) as applied to the efficient, high-precision grinding of structural ceramics, and describes work performed jointly by Dr. B.P. Bandyopadhyay, University of North Dakota, and Dr. R. Ohmori, of the Institute of Physical and Chemical Research (RINEN), Tokyo, Japan, from June through August, 1994. Dr. Ohmori pioneered the novel ELID grinding technology which incorporates electrolytically enhanced, in-process dressing of metal bonded superabrasive wheels. The principle of ELID grinding technology is discussed in the report as will its application for rough grinding and precision grinding. Two types of silicon nitride based ceramics (Kyocerals Si{sub 3}N{sub 4}, and Eaton`s SRBSN) were ground under various conditions with ELID methods. Mirror surface finishes were obtained with {number_sign} 4000 mesh size wheel (average grain size = 4 {mu}m). Results of these investigations are presented in this report. These include the effects of wheel bond type, type of power supply, abrasive grit friability, and cooling fluid composition. The effects of various parameters are discussed in terms of the mechanisms of ELID grinding, and in particular, the manner of boundary layer formation on the wheels and abrasive grit protrusion.

  17. The Effect of the Wear of Rotor Pins on Grinding Efficiency in a High-speed Disintegrator

    Directory of Open Access Journals (Sweden)

    Karel DVOŘÁK

    2018-02-01

    Full Text Available One of the directions intensively investigated in the field of milling is high-energy milling (HEM. One type of HEM is high-speed grinding in high-speed disintegrators. This type of mill is particularly suitable for the grinding and activation of fine powder materials. It has several advantages, such as a very intensive and continual refining process. One disadvantage is that its grinding pins are prone to abrasion, which may result in a decrease of the efficiency of grinding. This effect was investigated in this paper. Laboratory high speed disintegrator DESI 11 with steel pins was used. Portland clinker was chosen for the experiment, because of its average hardness. After each kilogram of the milled material, a sample was taken and the weight loss of the rotors was measured. The wear of the rotors was also measured using the 3D optical scanner ATOS Triple Scan. Results show that wear of rotors has a significant impact on the grinding efficiency.DOI: http://dx.doi.org/10.5755/j01.ms.24.1.17737

  18. An efficient, robust, and inexpensive grinding device for herbal samples like Cinchona bark

    DEFF Research Database (Denmark)

    Hansen, Steen Honoré; Holmfred, Else Skovgaard; Cornett, Claus

    2015-01-01

    An effective, robust, and inexpensive grinding device for the grinding of herb samples like bark and roots was developed by rebuilding a commercially available coffee grinder. The grinder was constructed to be able to provide various particle sizes, to be easy to clean, and to have a minimum...... of dead volume. The recovery of the sample when grinding as little as 50 mg of crude Cinchona bark was about 60%. Grinding is performed in seconds with no rise in temperature, and the grinder is easily disassembled to be cleaned. The influence of the particle size of the obtained powders on the recovery...

  19. An Efficient, Robust, and Inexpensive Grinding Device for Herbal Samples like Cinchona Bark.

    Science.gov (United States)

    Hansen, Steen Honoré; Holmfred, Else; Cornett, Claus; Maldonado, Carla; Rønsted, Nina

    2015-01-01

    An effective, robust, and inexpensive grinding device for the grinding of herb samples like bark and roots was developed by rebuilding a commercially available coffee grinder. The grinder was constructed to be able to provide various particle sizes, to be easy to clean, and to have a minimum of dead volume. The recovery of the sample when grinding as little as 50 mg of crude Cinchona bark was about 60%. Grinding is performed in seconds with no rise in temperature, and the grinder is easily disassembled to be cleaned. The influence of the particle size of the obtained powders on the recovery of analytes in extracts of Cinchona bark was investigated using HPLC.

  20. Efficient Havinga–Kondepudi resolution of conglomerate amino acid derivatives by slow cooling and abrasive grinding

    NARCIS (Netherlands)

    Leeman, Michel; Noorduin, Wim L.; Millemaggi, Alessia; Vlieg, Elias; Meekes, Hugo; Enckevort, Willem J.P. van; Kaptein, Bernard; Kellogg, Richard M.

    2010-01-01

    The complete resolution of the conglomerate racemates of two amino acid derivatives susceptible to racemization in solution was achieved by slow crystallization from a supersaturated solution accompanied by cooling and abrasive grinding.

  1. The Study on Grinding Ratio in Form Grinding with White Fused Alumina (WA) Grinding Wheels

    Science.gov (United States)

    Junming, Wang; Jiong, Wang; Deyuan, Lou

    2018-03-01

    The study is carried out based on an experiment of form grinding spur rack with white fused alumina (WA) grinding wheels. In the experiment, SOV-3020A type tri-axial image mapper is utilized to measure the profile of the tooth space in the rack, and the curve equations between the sectional area of the tooth space and the tooth sequence under different grinding depths are established by nonlinear curve regress using software of origin8.0. Then, it deduces the prediction equations for current grinding ratio and cumulative grinding ratio under different grinding depths. The result shows that the grinding ratio is exponential decline relationship with the increase of the number of the tooth to be ground under the same grinding depth, and the decline speed is fast in the initial stage. With the increase of grinding depth, the grinding ratio increases gradually. The cumulative grinding ratio is about twice as high as the current grinding ratio. Thus, large grinding depth is generally used in rough grinding to improve grinding efficiency.

  2. Crush Grinding

    International Nuclear Information System (INIS)

    Nguyen, T.Q.

    2005-01-01

    Crush Grinding is a special process used at the Kansas City Plant to finish stem sections of reservoir products. In this process, a precise profile of the desired product is formed on a tungsten carbide roll. This roll slowly transfers a mirror image of the profile onto the grinding surface of a wheel. The transfer rate of the profile is between 0.001 and 0.010 inches per minute. Crush grinding is desirable since it provides consistent surface finishes and thin walls at a high production rate. In addition, it generates very sharp fillet radii. However, crush grinding is a complex process since many variables affect the final product. Therefore, the process requires more attention and knowledge beyond basic metal removal practices. While the Kansas City Plant began using these machines in 1995, a formal study regarding crush grinding has not been conducted there. In addition, very little literature is available in the grinding industry regarding this process. As a result, new engineers at the Kansas City Plant must learn the process through trial and error. The purpose of this document is to address this literature deficit while specifically promoting a better understanding of the stem crush grinding process at the Kansas City Plant.

  3. Evaluating energy efficient strategies and product quality for distillers' dried grains with solubles (DDGS) in dry-grind ethanol plants

    Science.gov (United States)

    Lan, Tian

    The drying of distillers dried grains with solubles (DDGS), a coproduct of dry-grind corn processing to ethanol utilizes about 30% of the total energy required for the production of a liter of fuel ethanol. Therefore, improving DDGS drying energy efficiency could have significant impact on the economics of the dry-grind corn-to-ethanol process. Drying process improvements must take account into the effects of various drying strategies on the final quality of DDGS which is primarily utilized as a feed ingredient. Previous studies in the literature have shown that physical and chemical properties of DDGS vary according to the ratio of the two primarily feed streams, wet distillers grains (WDG) and condensed distillers solubles (CDS) which make up DDGS. Extensive research using plant-scale and bench-scale experiments have been conducted on the effect of process variables (ratios of WDG, CDS and DDGS add-back) during drying on the physical and chemical properties of DDGS. However, these investigations did not correlate the product characteristics data to drying efficiency. Additionally, it cannot be clearly determined from the literature on DDGS drying that processes used in the industry are optimized for both product quality and energy efficiency. A bench-scale rotary drum dryer heated by an electrically powered heat gun was used to investigate the effects of WDG, CDS and add-back ratios on both energy efficiency, drying performance and DDGS physical and chemical properties. A two stage drying process with the bench-scale rotary dryer was used to simulate the drying of DDGS using ICM (ICM, Inc., Colwich, KS) dry-grind process technology for DDGS drying which uses two rotary drum dryers in series. Effects of drying process variables, CDS content (0, 10, 20 and 40% by mass) and percent DDGS add-back (0, 20, 40 and 60% by mass) on energy performance and product quality were determined. Sixteen different drying strategies based on drying process variable ratios were

  4. Grinding Wheel Profile

    Science.gov (United States)

    2004-01-01

    curvature of the arced pathway in which the grinding tool spins.By overlaying appropriately scaled representations of the rock abrasion tool schematics, the evidence reveals a strong indication that the scrapes on the blueberry were induced by the tool, rather than caused by some natural geologic process.The two rectangular boxes in the lower left and upper middle parts of this image are 'drop outs,' where the data packets inadvertently did not make it back to Earth during the initial communications relay via the Deep Space Network antennas. The missing data packets should be resent to Earth within the next few days. Just above each of the black 'drop out' rectangles is another rectangular area filled with a cluster of smaller rectangles in different shades of gray, which are image compression artifacts.The rock abrasion tools on both Mars Exploration Rovers were supplied by Honeybee Robotics, New York, N.Y.

  5. A study of grinding characteristic of ferrule

    International Nuclear Information System (INIS)

    Lee, S. W.; Choi, H. Z.; Choi, Y. J.; Ahn, G. J.

    2003-01-01

    As recently optical communication industry is developed, request of optical communication part is increased. Ferrule is very important part which determines transmission efficiency and quality of information in the optical communication part. Most of ferrule processes are grinding which request high processing precision. Particularly, concentricity and cylindricity of inner and outer diameter is very important. The co-axle grinding process of ferrule is to make its concentricity all of uniform before centerless grinding. Surface integrity of ferrule is affected by kind of grinding wheels, grinding conditions, and characteristic of workpiece and equipment. In this study, surface integrity of workpiece according to change of grinding wheel speed, feed rate, regulating wheel speed and grinding force is investigate to improve the concentricity and roundness of ferrule from many experiments

  6. The grinding of uranium dioxide from fluidized beds

    International Nuclear Information System (INIS)

    Alonso Folgueras, J. A.

    1974-01-01

    This work deals with the UO 2 vibratory grinding, the UO 2 obtained from fluidized beds. In this study the grinding time has been correlated with surface area, stoichiometry, granulometry and grinded product contamination. The efficiency losses in the grinding of moisten UO 2 are outlined. Finally it is made a brief study of the granulate obtained from the grinded UO 2 as well as the green pellets resulting from it, taking into consideration the dispersion of its density and height. (Author)

  7. Effect of Deep Drying and Torrefaction Temperature on Proximate, Ultimate Composition, and Heating Value of 2-mm Lodgepole Pine (Pinus contorta) Grind

    Energy Technology Data Exchange (ETDEWEB)

    Tumuluru, Jaya

    2016-06-01

    Deep drying and torrefaction is a thermal pretreatment method, where biomass is heated in the temperature range of 150–300°C in an inert or reduced environment. The process parameters like temperature and residence time has a significant impact on proximate, ultimate, and energy properties of the biomass. In the present study, torrrefaction experiments were conducted on 2 mm lodgepole pine grind using a thermogravimetric analyzer. Both deep drying and torrefaction temperature (160–270°C) and time (15–120 min) were selected. Torrefied samples were analyzed for proximate, ultimate and energy properties. Results indicated that moisture content decreased with increases in torrefaction temperature and time, where at 270°C and 120 min, the moisture content was found to be 1.15% (w.b.). Volatile content in the biomass decreased from about 80% to about 45%, and ash content increased from 0.77 to about 1.91% at 270°C and 120 min. The hydrogen, oxygen and sulfur content decreased to 3%, 28.24%, and 0.01 whereas carbon content and higher heating value increased to 68.86% and 23.67 MJ/kg at 270°C and 120 min. H/C and O/C ratio calculated at 270°C and 120 min residence time were about 0.56 and 0.47. This study indicated that higher torrefaction temperatures >230°C and residence time >15 min influenced the proximate, ultimate, and energy properties.

  8. Tool grinding machine

    Science.gov (United States)

    Dial, Sr., Charles E.

    1980-01-01

    The present invention relates to an improved tool grinding mechanism for grinding single point diamond cutting tools to precise roundness and radius specifications. The present invention utilizes a tool holder which is longitudinally displaced with respect to the remainder of the grinding system due to contact of the tool with the grinding surface with this displacement being monitored so that any variation in the grinding of the cutting surface such as caused by crystal orientation or tool thickness may be compensated for during the grinding operation to assure the attainment of the desired cutting tool face specifications.

  9. Improved tool grinding machine

    Science.gov (United States)

    Dial, C.E. Sr.

    The present invention relates to an improved tool grinding mechanism for grinding single point diamond cutting tools to precise roundness and radius specifications. The present invention utilizes a tool holder which is longitudinally displaced with respect to the remainder of the grinding system due to contact of the tool with the grinding surface with this displacement being monitored so that any variation in the grinding of the cutting surface such as caused by crystal orientation or tool thicknesses may be compensated for during the grinding operation to assure the attainment of the desired cutting tool face specifications.

  10. Conduit grinding apparatus

    Science.gov (United States)

    Nachbar, Henry D.; Korytkowski, Alfred S.

    1991-01-01

    A grinding apparatus for grinding the interior portion of a valve stem receiving area of a valve. The apparatus comprises a faceplate, a plurality of cams mounted to an interior face of the faceplate, a locking bolt to lock the faceplate at a predetermined position on the valve, a movable grinder and a guide tube for positioning an optical viewer proximate the area to be grinded. The apparatus can either be rotated about the valve for grinding an area of the inner diameter of a valve stem receiving area or locked at a predetermined position to grind a specific point in the receiving area.

  11. Low specific-grinding energy machining of ceramics by a laser dressed diamond grinding stone

    International Nuclear Information System (INIS)

    Jodan, K.; Matsumaru, K.; Ishizaki, K.

    2003-01-01

    A laser dressing is an effective dressing method to accomplish efficient ceramic grinding. Since laser dressing achieves protrusion heights of abrasive-grains without grain dislodgment, the number of abrasive-grains in a laser dressed grinding stone (LGS) is higher than that in a mechanically dressed grinding stone (MGS), remaining the initial grain distribution. Thus, the LGS contains higher number of effective cutting edges, and forms higher number of ground grooves on a ground surface than the MGS. Consequently, the LGS can achieve lower specific grinding energy than the MGS. Copyright (2003) AD-TECH - International Foundation for the Advancement of Technology Ltd

  12. modeling grinding modeling grinding processes as micro processes

    African Journals Online (AJOL)

    eobe

    industrial precision grinding processes are cylindrical, center less and ... Several model shave been proposed and used to study grinding ..... grinding force for the two cases were 9.07237N/mm ..... International Journal of Machine Tools &.

  13. Combustion stability and thermal efficiency in a porous media burner for LPG cooking in the food industry using Al_2O_3 particles coming from grinding wastes

    International Nuclear Information System (INIS)

    Herrera, Bernardo; Cacua, Karen; Olmos-Villalba, Luis

    2015-01-01

    Cooking is one of the most thermal-energy consuming processes in the food industry and development of devices that contribute to decrease the consumption of fossil fuel is a matter of great importance. This decreasing in consumption can both enlarge competitiveness in the enterprises of this sector and reduce emissions of greenhouse gases and other toxic combustion by products such as, carbon monoxide and nitrogen oxides. A porous burner made of a bed of Al_2O_3 particles coming from grinding residues and combined with ceramic foam of SiSiC has been evaluated respect to Liquefied Petroleum Gas combustion stability and thermal efficiency for cooking in food industry. The results showed that for specific heat input rate lower than 154 kW/m"2, the upper and lower equivalence ratio on the stability limit follow approximately a linear trend, as well as the wide of the range of stability remains constant. But this trend is broken when higher heat input rate is applied. Also, every equivalence ratio for stable combustion was in the lean ratio and stoichiometric combustion values were not feasible because flashback occurred. Emissions of CO were in acceptable values lower than 25 ppm for specific heat input rate lower than 154 kW/m"2 but an important rising in the CO emissions could be seen when the burner worked at higher heat input rate due to a moderate lift-off and quenching on the surface of the burner. Thermal efficiency was calculated in two different working ways: the “radiation–convection” and “conduction”. Thermal efficiency in the “radiation–convection” was between 15.7% and 23.6%, which are lower than the average thermal efficiency of the conventional free-flame burner. But the “conduction” mode showed a significant advantage respect to free flame conventional burners, since it could improve the thermal efficiency between 7% and 14%. The improvement in efficiency and the possibility of interrupting the flow of fuel in a cyclical operation

  14. Towards High Productivity in Precision Grinding

    Directory of Open Access Journals (Sweden)

    W. Brian Rowe

    2018-04-01

    Full Text Available Over the last century, substantial advances have been made, based on improved understanding of the requirements of grinding processes, machines, control systems, materials, abrasives, wheel preparation, coolants, lubricants, and coolant delivery. This paper reviews a selection of areas in which the application of scientific principles and engineering ingenuity has led to the development of new grinding processes, abrasives, tools, machines, and systems. Topics feature a selection of areas where relationships between scientific principles and new techniques are yielding improved productivity and better quality. These examples point towards further advances that can fruitfully be pursued. Applications in modern grinding technology range from high-precision kinematics for grinding very large lenses and reflectors through to medium size grinding machine processes and further down to grinding very small components used in micro electro-mechanical systems (MEMS devices. The importance of material issues is emphasized for the range of conventional engineering steels, through to aerospace materials, ceramics, and composites. It is suggested that future advances in productivity will include the wider application of artificial intelligence and robotics to improve precision, process efficiency, and features required to integrate grinding processes into wider manufacturing systems.

  15. Grinding Away Microfissures

    Science.gov (United States)

    Booth, Gary N.; Malinzak, R. Michael

    1990-01-01

    Treatment similar to dental polishing used to remove microfissures from metal parts without reworking adjacent surfaces. Any variety of abrasive tips attached to small motor used to grind spot treated. Configuration of grinding head must be compatible with configurations of motor and workpiece. Devised to eliminate spurious marks on welded parts.

  16. Grinding Wheel System

    Science.gov (United States)

    Malkin, Stephen; Gao, Robert; Guo, Changsheng; Varghese, Biju; Pathare, Sumukh

    2003-08-05

    A grinding wheel system includes a grinding wheel with at least one embedded sensor. The system also includes an adapter disk containing electronics that process signals produced by each embedded sensor and that transmits sensor information to a data processing platform for further processing of the transmitted information.

  17. Multifunctional centrifugal grinding unit

    Science.gov (United States)

    Sevostyanov, V. S.; Uralskij, V. I.; Uralskij, A. V.; Sinitsa, E. V.

    2018-03-01

    The article presents scientific and engineering developments of multifunctional centrifugal grinding unit in which the selective effect of grinding bodies on the crushing material is realized, depending on its physical and mechanical characteristics and various schemes for organizing the technological process

  18. Efficient collective swimming by harnessing vortices through deep reinforcement learning.

    Science.gov (United States)

    Verma, Siddhartha; Novati, Guido; Koumoutsakos, Petros

    2018-06-05

    Fish in schooling formations navigate complex flow fields replete with mechanical energy in the vortex wakes of their companions. Their schooling behavior has been associated with evolutionary advantages including energy savings, yet the underlying physical mechanisms remain unknown. We show that fish can improve their sustained propulsive efficiency by placing themselves in appropriate locations in the wake of other swimmers and intercepting judiciously their shed vortices. This swimming strategy leads to collective energy savings and is revealed through a combination of high-fidelity flow simulations with a deep reinforcement learning (RL) algorithm. The RL algorithm relies on a policy defined by deep, recurrent neural nets, with long-short-term memory cells, that are essential for capturing the unsteadiness of the two-way interactions between the fish and the vortical flow field. Surprisingly, we find that swimming in-line with a leader is not associated with energetic benefits for the follower. Instead, "smart swimmer(s)" place themselves at off-center positions, with respect to the axis of the leader(s) and deform their body to synchronize with the momentum of the oncoming vortices, thus enhancing their swimming efficiency at no cost to the leader(s). The results confirm that fish may harvest energy deposited in vortices and support the conjecture that swimming in formation is energetically advantageous. Moreover, this study demonstrates that deep RL can produce navigation algorithms for complex unsteady and vortical flow fields, with promising implications for energy savings in autonomous robotic swarms.

  19. Comparison of Grinding Characteristics of Converter Steel Slag with and without Pretreatment and Grinding Aids

    Directory of Open Access Journals (Sweden)

    Jihui Zhao

    2016-10-01

    Full Text Available The converter steel slag cannot be widely used in building materials for its poor grindability. In this paper, the grinding characteristics of untreated and pretreated (i.e., magnetic separation steel slag were compared. Additionally, the grinding property of pretreated steel slag was also studied after adding grinding aids. The results show that the residues (i.e., oversize substance that passed a 0.9 mm square-hole screen can be considered as the hardly grinding phases (HGP and its proportion is about 1.5%. After the initial 20 min grinding, the RO phase (RO phase is a continuous solid solution which is composed of some divalent metal oxides, such as FeO, MgO, MnO, CaO, etc., calcium ferrite, and metallic iron phase made up most of the proportion of the HGP, while the metallic iron made up the most component after 70 min grinding. The D50 of untreated steel slag could only reach 32.89 μm after 50 min grinding, but that of pretreated steel slag could reach 18.16 μm after the same grinding time. The grinding efficiency of steel slag was obviously increased and the particle characteristics were improved after using grinding aids (GA, especially the particle proportions of 3–32 μm were obviously increased by 7.24%, 7.22%, and 10.63% after 40 min, 50 min, and 60 min grinding, respectively. This is mainly because of the reduction of agglomeration and this effect of GA was evidenced by SEM (scanning electron microscope images.

  20. Narrowing the uncertainty for deep-ocean injection efficiency

    Energy Technology Data Exchange (ETDEWEB)

    Orr, J.C.; Aumont, O. [Laboratoire des Sciences du Climat et de l' Environnement, CEA-CNRS, Gif-sur-Yvette (France); Yool, A. [Southampton Oceanography Centre, Southampton (United Kingdom); Plattner, G.K.; Joos, F. [Bern Univ., Bern (Switzerland). Physics Inst.; Maier-Reimer, E. [Max Planck Inst. fuer Meteorologie, Hamburg (Germany); Weirig, M.F.; Schlitzer, R. [Alfred Wegener Inst. for Polar and Marine Research, Bremerhaven (Germany); Caldeira, K.; Wickett, M.E. [Lawrence Livermore National Laboratory, CA (United States); Matear, R.J. [Australian Commonwealth Scientific and Research Organization, Hobart (Australia); Mignone, B.K.; Sarmiento, J.L. [Princeton Univ., Princeton, NJ (United States). AOS Program

    2005-07-01

    Ten ocean general circulation models (OCGMs) were compared as part of an international study investigating the ocean's ability to efficiently sequester carbon dioxide (CO{sub 2}). The models were selected for their ability to simulate radiocarbon and CFC-11. All of the model simulations neglected the influence of marine biota, and the simulations used only dissolved inorganic carbon (DIC) as a tracer in order to conserve computing resources. The models were integrated using standard ocean carbon-cycle model intercomparison project (OCMIP) formulations for gas exchange boundary conditions to obtain pre-industrial conditions. All models used the same predefined atmospheric CO{sub 2} records compiled from 1765 to 2000, as well as future scenarios in which atmospheric CO{sub 2} was stabilized at 650 ppm. Injections occurred over a period of 100 years. Results of the study showed that global budgets for CFC-11 and radiocarbon were correlated with global efficiencies for a 3000 m injection simulation. The 3000 m injection efficiency was then correlated with the global mean for deep natural radiocarbon. Results showed that simultaneously accounting for constraints from both CFC-11 and natural radiocarbon narrowed the range for a 3000 m injection efficiency in the year 2500 by a factor of 4. The study showed that models must be able to simulate global inventories for CFC-11 as well as global means for radiocarbon in deep ocean scenarios in order to be credible. It was concluded that models using both constraints will more accurately simulate global injection efficiencies.

  1. Bearing restoration by grinding

    Science.gov (United States)

    Hanau, H.; Parker, R. J.; Zaretsky, E. V.; Chen, S. M.; Bull, H. L.

    1976-01-01

    A joint program was undertaken by the NASA Lewis Research Center and the Army Aviation Systems Command to restore by grinding those rolling-element bearings which are currently being discarded at aircraft engine and transmission overhaul. Three bearing types were selected from the UH-1 helicopter engine (T-53) and transmission for the pilot program. No bearing failures occurred related to the restoration by grinding process. The risk and cost of a bearing restoration by grinding programs was analyzed. A microeconomic impact analysis was performed.

  2. AN EFFICIENT METHOD FOR DEEP WEB CRAWLER BASED ON ACCURACY -A REVIEW

    OpenAIRE

    Pranali Zade1, Dr.S.W.Mohod2

    2018-01-01

    As deep web grows at a very fast pace, there has been increased interest in techniques that help efficiently locate deep-web interfaces. However, due to the large volume of web resources and the dynamic nature of deep web, achieving wide coverage and high efficiency is a challenging issue. We propose a three-stage framework, for efficient harvesting deep web interfaces. Project experimental results on a set of representative domains show the agility and accuracy of our proposed crawler framew...

  3. Synthesis of high efficient Cu/TiO2 photocatalysts by grinding and their size-dependent photocatalytic hydrogen production

    Science.gov (United States)

    Ni, Dawei; Shen, Haiyan; Li, Huiqiao; Ma, Ying; Zhai, Tianyou

    2017-07-01

    Recently, copper species have been extensively investigated to replace Pt as efficient co-catalysts for the evolution of H2 due to their low cost and relatively high activity. Cu nanoparticles less than 5 nm are successfully decorated on TiO2 surface in this work by an easy and mild milling process. These Cu nanoparticles are highly dispersed on TiO2 when the loading amount of Cu is no more than 10 wt%. The sizes of Cu nanoparticles can be controlled by changing the milling environment and decrease in the order of Cu-ethanol > Cu-water > Cu nanoparticles obtained through drying milling. The highest and stable hydrogen generation can be realized on Cu/TiO2 with 2.0 wt% Cu and sizes of Cu nanoparticles ranging from 2 to 4 nm, in which high and stable photocurrent confirms promoted photogenerated charge separation. Smaller Cu clusters are demonstrated to be detrimental to hydrogen evolution at same Cu content. High loading of Cu nanoparticles of 2-4 nm will benefit photogenerated electron-hole recombination and thus decrease the activity of Cu/TiO2. The results here demonstrate the key roles of Cu cluster size in addition to Cu coverage on photocatalytic activity of Cu/TiO2 composite photocatalysts.

  4. Synthesis of high efficient Cu/TiO2 photocatalysts by grinding and their size-dependent photocatalytic hydrogen production

    International Nuclear Information System (INIS)

    Ni, Dawei; Shen, Haiyan; Li, Huiqiao; Ma, Ying; Zhai, Tianyou

    2017-01-01

    Highlights: • Cu nanodots were decorated on TiO 2 surface through ball milling method. • Its size distribution was investigated in water and ethanolic medium. • Photocurrent response and hydrogen evolution was improved. • Performance was found to be dependent on size of Cu nanodots. - Abstract: Recently, copper species have been extensively investigated to replace Pt as efficient co-catalysts for the evolution of H 2 due to their low cost and relatively high activity. Cu nanoparticles less than 5 nm are successfully decorated on TiO 2 surface in this work by an easy and mild milling process. These Cu nanoparticles are highly dispersed on TiO 2 when the loading amount of Cu is no more than 10 wt%. The sizes of Cu nanoparticles can be controlled by changing the milling environment and decrease in the order of Cu-ethanol > Cu-water > Cu nanoparticles obtained through drying milling. The highest and stable hydrogen generation can be realized on Cu/TiO 2 with 2.0 wt% Cu and sizes of Cu nanoparticles ranging from 2 to 4 nm, in which high and stable photocurrent confirms promoted photogenerated charge separation. Smaller Cu clusters are demonstrated to be detrimental to hydrogen evolution at same Cu content. High loading of Cu nanoparticles of 2–4 nm will benefit photogenerated electron-hole recombination and thus decrease the activity of Cu/TiO 2 . The results here demonstrate the key roles of Cu cluster size in addition to Cu coverage on photocatalytic activity of Cu/TiO 2 composite photocatalysts.

  5. Development of Composite Grinding Wheels for Hard and Soft Metals

    OpenAIRE

    Pruti, Faruk

    2012-01-01

    This research investigates the performance of grinding wheel in terms of its internal granular particles and their effect on the surface finish for both soft and hard metals subjected to both dry and wet conditions of use. The study considers the properties of materials of construction including hardness of the granular particles and their size and distributions that affects the grinding wheel efficiency in abrading of soft and hard metal surfaces. Furthermore, in order to improve grinding pe...

  6. Grinding temperature and energy ratio coe cient in MQL grinding of high-temperature nickel-base alloy by using di erent vegetable oils as base oil

    Institute of Scientific and Technical Information of China (English)

    Li Benkai; Li Changhe; Zhang Yanbin; Wang Yaogang; Jia Dongzhou; Yang Min

    2016-01-01

    Vegetable oil can be used as a base oil in minimal quantity of lubrication (MQL). This study compared the performances of MQL grinding by using castor oil, soybean oil, rapeseed oil, corn oil, sunflower oil, peanut oil, and palm oil as base oils. A K-P36 numerical-control precision surface grinder was used to perform plain grinding on a workpiece material with a high-temperature nickel base alloy. A YDM–III 99 three-dimensional dynamometer was used to measure grinding force, and a clip-type thermocouple was used to determine grinding temperature. The grinding force, grind-ing temperature, and energy ratio coefficient of MQL grinding were compared among the seven veg-etable oil types. Results revealed that (1) castor oil-based MQL grinding yields the lowest grinding force but exhibits the highest grinding temperature and energy ratio coefficient;(2) palm oil-based MQL grinding generates the second lowest grinding force but shows the lowest grinding temperature and energy ratio coefficient;(3) MQL grinding based on the five other vegetable oils produces similar grinding forces, grinding temperatures, and energy ratio coefficients, with values ranging between those of castor oil and palm oil;(4) viscosity significantly influences grinding force and grinding tem-perature to a greater extent than fatty acid varieties and contents in vegetable oils;(5) although more viscous vegetable oil exhibits greater lubrication and significantly lower grinding force than less vis-cous vegetable oil, high viscosity reduces the heat exchange capability of vegetable oil and thus yields a high grinding temperature;(6) saturated fatty acid is a more efficient lubricant than unsaturated fatty acid;and (7) a short carbon chain transfers heat more effectively than a long carbon chain. Palm oil is the optimum base oil of MQL grinding, and this base oil yields 26.98 N tangential grinding force, 87.10 N normal grinding force, 119.6 °C grinding temperature, and 42.7%energy ratio coefficient

  7. Analysis on the grinding quality of palm oil fibers by using combined grinding equipment

    Science.gov (United States)

    Gan, H. L.; Gan, L. M.; Law, H. C.

    2015-12-01

    As known, Malaysia is the second largest palm oil producer worldwide after Indonesia, therefore indicating the abundance of its wastes within the country. The plantation would be seen to increase to at least 5.2 million ha by 2020, and the waste generation would be 50-70 times the plantation. However, the efficiency of bulk density is reduced. This is one of the main reasons of the initiation of this size reduction/ grinding research. With appropriate parameters, grinding will be seen to be helping in enhancing the inter-particle bindings, subsequently increasing the quality of final products. This paper focuses on the grinding quality involving palm oil wastes by using the Scanning Electron Microscope (SEM). The samples would first be ground to powder at varying grinding speed and finally got the randomly chosen particles measured to obtain the size range. The grinding speed was manipulated from 15 Hz to 40 Hz. From the data obtained, it was found the particles fineness increased with increasing grinding speed. In general, the size ranged from 45 μm to about 600 μm, where the finest was recorded at the speed of 40 Hz. It was also found that the binding was not so encouraging at very low speeds. Therefore, the optimum grinding speed for oil palm residues lied in the range of 25 Hz to 30 Hz. However, there were still limitations to be overcome if the accuracy of the image clarity is to be enhanced.

  8. Energy-effective Grinding of Inorganic Solids Using Organic Additives.

    Science.gov (United States)

    Mishra, Ratan K; Weibel, Martin; Müller, Thomas; Heinz, Hendrik; Flatt, Robert J

    2017-08-09

    We present our research findings related to new formulations of the organic additives (grinding aids) needed for the efficient grinding of inorganic solids. Even though the size reduction phenomena of the inorganic solid particles in a ball mill is purely a physical process, the addition of grinding aids in milling media introduces a complex physicochemical process. In addition to further gain in productivity, the organic additive helps to reduce the energy needed for grinding, which in the case of cement clinker has major environmental implications worldwide. This is primarily due to the tremendous amounts of cement produced and almost 30% of the associated electrical energy is consumed for grinding. In this paper, we examine the question of how to optimize these grinding aids linking molecular insight into their working mechanisms, and also how to design chemical additives of improved performance for industrial comminution.

  9. Performance assessment of river sand versus ceramic grinding media on the Fimiston Ultra-fine Grinding application

    International Nuclear Information System (INIS)

    Blake, Guillaume; Clermont, Benoit; Gianatti, Christopher

    2012-01-01

    Ultra-fine grinding increases the amenability of the refractory concentrate to direct cyanide leaching. Low cost media such as silica river sand gives very fine product grind sizes, however the sand media is quite angular and is often supplied with a broad size distribution. It is generally accepted that the use of a ceramic grinding media will result in a finer product size or allow an increase in the mill throughput. The capacity of a mill is known to increase with decreasing grinding media diameter, the mill wear can be decreased and efficiency of grinding increased. Magotteaux Keramax-MTX Ceramic grinding media was purchased for a plant trial, to assess its' performance.

  10. Grinding temperature and energy ratio coefficient in MQL grinding of high-temperature nickel-base alloy by using different vegetable oils as base oil

    Directory of Open Access Journals (Sweden)

    Li Benkai

    2016-08-01

    Full Text Available Vegetable oil can be used as a base oil in minimal quantity of lubrication (MQL. This study compared the performances of MQL grinding by using castor oil, soybean oil, rapeseed oil, corn oil, sunflower oil, peanut oil, and palm oil as base oils. A K-P36 numerical-control precision surface grinder was used to perform plain grinding on a workpiece material with a high-temperature nickel base alloy. A YDM–III 99 three-dimensional dynamometer was used to measure grinding force, and a clip-type thermocouple was used to determine grinding temperature. The grinding force, grinding temperature, and energy ratio coefficient of MQL grinding were compared among the seven vegetable oil types. Results revealed that (1 castor oil-based MQL grinding yields the lowest grinding force but exhibits the highest grinding temperature and energy ratio coefficient; (2 palm oil-based MQL grinding generates the second lowest grinding force but shows the lowest grinding temperature and energy ratio coefficient; (3 MQL grinding based on the five other vegetable oils produces similar grinding forces, grinding temperatures, and energy ratio coefficients, with values ranging between those of castor oil and palm oil; (4 viscosity significantly influences grinding force and grinding temperature to a greater extent than fatty acid varieties and contents in vegetable oils; (5 although more viscous vegetable oil exhibits greater lubrication and significantly lower grinding force than less viscous vegetable oil, high viscosity reduces the heat exchange capability of vegetable oil and thus yields a high grinding temperature; (6 saturated fatty acid is a more efficient lubricant than unsaturated fatty acid; and (7 a short carbon chain transfers heat more effectively than a long carbon chain. Palm oil is the optimum base oil of MQL grinding, and this base oil yields 26.98 N tangential grinding force, 87.10 N normal grinding force, 119.6 °C grinding temperature, and 42.7% energy

  11. Efficient generation of image chips for training deep learning algorithms

    Science.gov (United States)

    Han, Sanghui; Fafard, Alex; Kerekes, John; Gartley, Michael; Ientilucci, Emmett; Savakis, Andreas; Law, Charles; Parhan, Jason; Turek, Matt; Fieldhouse, Keith; Rovito, Todd

    2017-05-01

    Training deep convolutional networks for satellite or aerial image analysis often requires a large amount of training data. For a more robust algorithm, training data need to have variations not only in the background and target, but also radiometric variations in the image such as shadowing, illumination changes, atmospheric conditions, and imaging platforms with different collection geometry. Data augmentation is a commonly used approach to generating additional training data. However, this approach is often insufficient in accounting for real world changes in lighting, location or viewpoint outside of the collection geometry. Alternatively, image simulation can be an efficient way to augment training data that incorporates all these variations, such as changing backgrounds, that may be encountered in real data. The Digital Imaging and Remote Sensing Image Image Generation (DIRSIG) model is a tool that produces synthetic imagery using a suite of physics-based radiation propagation modules. DIRSIG can simulate images taken from different sensors with variation in collection geometry, spectral response, solar elevation and angle, atmospheric models, target, and background. Simulation of Urban Mobility (SUMO) is a multi-modal traffic simulation tool that explicitly models vehicles that move through a given road network. The output of the SUMO model was incorporated into DIRSIG to generate scenes with moving vehicles. The same approach was used when using helicopters as targets, but with slight modifications. Using the combination of DIRSIG and SUMO, we quickly generated many small images, with the target at the center with different backgrounds. The simulations generated images with vehicles and helicopters as targets, and corresponding images without targets. Using parallel computing, 120,000 training images were generated in about an hour. Some preliminary results show an improvement in the deep learning algorithm when real image training data are augmented with

  12. Nitramine Drying & Fine Grinding Facility

    Data.gov (United States)

    Federal Laboratory Consortium — The Nitramine Drying and Fine Grinding Facility provides TACOM-ARDEC with a state-of-the-art facility capable of drying and grinding high explosives (e.g., RDX and...

  13. Design and experimental study of a micro-groove grinding wheel with spray cooling effect

    Directory of Open Access Journals (Sweden)

    Shi Chaofeng

    2014-04-01

    Full Text Available The effectiveness of grinding fluid supply has a crucial impact on grinding quality and efficiency in high speed grinding. In order to improve the cooling and lubrication, through in-depth research of self-inhaling internal cooling method and intermittent grinding mechanism, a new spray cooling method used in high speed grinding is proposed. By referring to the structure of bowl-shaped dispersion disk, the grinding wheel matrix with atomization ability is designed; through studying heat transfer of droplet collision and the influence of micro-groove on the boiling heat transfer, grinding segment with micro-groove is designed to enhance the heat flux of coolant and achieve maximum heat transfer between droplets and grinding contact zone. High-speed grinding experiments on GH4169 with the developed grinding wheel are carried out. The results show that with the micro-groove grinding wheel just 5.4% of pump outlet flow rate and 0.5% of spindle energy is needed to reduce the grinding temperature to 200 °C, which means the developed grinding wheel makes cooling high efficient and low energy consuming.

  14. Grinding kinetics and equilibrium states

    Science.gov (United States)

    Opoczky, L.; Farnady, F.

    1984-01-01

    The temporary and permanent equilibrium occurring during the initial stage of cement grinding does not indicate the end of comminution, but rather an increased energy consumption during grinding. The constant dynamic equilibrium occurs after a long grinding period indicating the end of comminution for a given particle size. Grinding equilibrium curves can be constructed to show the stages of comminution and agglomeration for certain particle sizes.

  15. Development of ELID mirror surface grinding by cast iron bond grinding wheel. Ohkochi memorial technology prize; Chutetsu bond toishi ni yoru denkai inpurosesu doresshingu (ELID) kyomen kensakuho no kaihatsu. Okochi kinen gijutsusho jusho ni yosete

    Energy Technology Data Exchange (ETDEWEB)

    Omori, H.; Takahashi, I. [Institute of Physical and Chemical Research, Tokyo (Japan); Nakagawa, T. [The University of Tokyo, Tokyo (Japan). Institute of Industrial Science; Hagiuda, Y.; Karikome, K. [Tokyo Metropolitan College of Aeronautical Engineering, Tokyo (Japan)

    1997-08-01

    Development was accomplished on the electrolytic in-process dressing (ELID) mirror surface grinding process using a cast iron bonded grinding wheel. This paper describes the history of the development, which may be summarized as follows: a study was begun on powder forging of cutting chips in 1970; a research was started on powder forging of decarburized cast iron powder; developments were made on powder metallurgy of cast irons and cast iron bonded lapping tools in 1980, and cast iron bonded diamond grinding wheels were put on the market; a high-efficiency grinding process using MC and cast iron fiber-bonded grinding wheels were developed in 1985 and the grinding wheels made therefrom were put on the market; and a study was begun on the ELID grinding in 1987, and marketing was started on power supply, grinding liquid and tools for the ELID grinding process in 1990. Discussions on converting raw materials for the powder forging into cutting chips have triggered developing the cast iron bonded grinding wheel. The cast iron bonded diamond grinding wheel improves dressability and sharpness of conventional grinding wheels. The grinding wheel is fabricated by mixing carbonyl iron powder, diamond grinding grains and cast iron powder, pressing the mixture in a die, sintering it at 1140 degC, and assembling and dressing the sinter. The grinding stone can grind high-tech materials. 4 figs.

  16. Electro-chemical grinding

    Science.gov (United States)

    Feagans, P. L.

    1972-01-01

    Electro-chemical grinding technique has rotation speed control, constant feed rates, and contour control. Hypersonic engine parts of nickel alloys can be almost 100% machined, keeping tool pressure at virtual zero. Technique eliminates galling and permits constant surface finish and burr-free interrupted cutting.

  17. Ultrasonic grinding of optical materials

    Science.gov (United States)

    Cahill, Michael; Bechtold, Michael; Fess, Edward; Stephan, Thomas; Bechtold, Rob

    2017-10-01

    Hard ceramic optical materials such as sapphire, ALON, Spinel, PCA, or Silicon Carbide can present a significant challenge in manufacturing precision optical components due to their tough mechanical properties. These are also the same mechanical properties that make them desirable materials when used in harsh environments. Slow processing speeds, premature tool wear, and poor surface quality are common results of the tough mechanical properties of these materials. Often, as a preparatory stage for polishing, the finish of the ground surface greatly influences the polishing process and the resulting finished product. To overcome these challenges, OptiPro Systems has developed an ultrasonic assisted grinding technology, OptiSonic, which has been designed for the precision optics and ceramics industry. OptiSonic utilizes a custom tool holder designed to produce oscillations, in microns of amplitude, in line with the rotating spindle. A software package, IntelliSonic, is integral to the function of this platform. IntelliSonic can automatically characterize tooling during setup to identify and select the ideal resonant peak which to operate at. Then, while grinding, IntelliSonic continuously adjusts the output frequency for optimal grinding efficiency while in contact with the part. This helps maintain a highly consistent process under changing load conditions for a more precise surface. Utilizing a variety of instruments, tests have proven to show a reduction in force between tool and part by up to 50%, while increasing the surface quality and reducing tool wear. This paper will present the challenges associated with these materials and solutions created to overcome them.

  18. Adhesive wear mechanism under combined electric diamond grinding

    Directory of Open Access Journals (Sweden)

    Popov Vyacheslav

    2017-01-01

    Full Text Available The article provides a scientific substantiation of loading of metal-bond diamond grinding wheels and describes the mechanism of contact interaction (interlocking of wheels with tool steel as well as its general properties having an influence on combined electric diamond grinding efficiency. The study concluded that a loaded layer can be formed in a few stages different by nature. It is known, that one of the causes of grinding degradation is a continuous loading of active grits (abrasive grinding tool by workpiece chips. It all affects the diamond grinding wheels efficiency and grinding ability with a result in increase of tool pressure, contact temperature and wheels specific removal rate. Science has partially identified some various methods to minimize grinding wheel loading, however, as to loading of metal-bond diamond grinding wheels the search is still in progress. Therefore, research people have to state, that in spite of the fact that the wheels made of cubic boron nitride are of little use as applied to ceramic, ultrahard, hard-alloyed hard-to-machine and nano-materials of the time, but manufactures have to apply cubic boron nitride wheels wherein diamond ones preferable.

  19. Efficient fluorescent deep-blue and hybrid white emitting devices based on carbazole/benzimidazole compound

    KAUST Repository

    Yang, Xiaohui; Zheng, Shijun; Bottger, Rebecca; Chae, HyunSik; Tanaka, Takeshi; Li, Sheng; Mochizuki, Amane; Jabbour, Ghassan E.

    2011-01-01

    We report the synthesis, photophysics, and electrochemical characterization of carbazole/benzimidazole-based compound (Cz-2pbb) and efficient fluorescent deep-blue light emitting devices based on Cz-2pbb with the peak external quantum efficiency

  20. The influence of grinding oil viscosity on grinding heat and burn damage in creep-feed grinding{copyright}

    Energy Technology Data Exchange (ETDEWEB)

    Zhen-Change Liu [Shandong Univ. of Technology, Jinan (China); Abe, Satoshi; Noda, Masahiro [Yushiro Chemical Industry Co. Ltd., Kanagawa (Japan)

    1995-08-01

    Grinding oils are widely used in precision grinding, such as tool grinding, thread grinding and gear grinding, during which processes grinding burn is the most prevalent damage affecting the integrity of ground surface. This paper discusses the influence of oil viscosity on grinding heat and burn damage in creep-feed-grinding. Experimental results indicated that, under lighter grinding conditions, the effects of oil viscosity was not observed, but under heavy grinding conditions grinding burn occurred when using low viscosity oil. When the viscosity of the oil was increased, grinding heat and burn damage tended to be reduced. As the viscosity was increased to a certain level, grinding burn reduction, by further increasing the viscosity, became less while other problems such as much higher oil pump noise and reduced oil flow occurred. It is clear that a viscosity limit exists for given grinding conditions. 5 refs., 4 figs., 3 tabs.

  1. Effect of Deep Drying and Torrefaction Temperature on Proximate, Ultimate Composition, and Heating Value of 2-mm Lodgepole Pine (Pinus contorta) Grind.

    Science.gov (United States)

    Tumuluru, Jaya Shankar

    2016-06-22

    Deep drying and torrefaction compose a thermal pretreatment method where biomass is heated in the temperature range of 150-300 °C in an inert or reduced environment. The process parameters, like torrefaction temperature and residence time, have a significant impact on the proximate, ultimate, and energy properties. In this study, torrefaction experiments were conducted on 2-mm ground lodgepole pine ( Pinus contorta ) using a thermogravimetric analyzer. Both deep drying and torrefaction temperature (160-270 °C) and time (15-120 min) were selected. Torrefied samples were analyzed for the proximate, ultimate, and higher heating value. The results indicate that moisture content decreases with increases in torrefaction temperature and time, where at 270 °C and 120 min, the moisture content is found to be 1.15% (w.b.). Volatile content in the lodgepole pine decreased from about 80% to about 45%, and ash content increased from 0.77% to about 1.91% at 270 °C and 120 min. The hydrogen, oxygen, and sulfur content decreased to 3%, 28.24%, and 0.01%, whereas the carbon content and higher heating value increased to 68.86% and 23.67 MJ/kg at 270 °C and 120 min. Elemental ratio of hydrogen to carbon and oxygen to carbon (H/C and O/C) calculated at 270 °C and a 120-min residence time were about 0.56 and 0.47. Based on this study, it can be concluded that higher torrefaction temperatures ≥230 °C and residence time ≥15 min influence the proximate, ultimate, and energy properties of ground lodgepole pine.

  2. Effect of Deep Drying and Torrefaction Temperature on Proximate, Ultimate Composition, and Heating Value of 2-mm Lodgepole Pine (Pinus contorta Grind

    Directory of Open Access Journals (Sweden)

    Jaya Shankar Tumuluru

    2016-06-01

    Full Text Available Deep drying and torrefaction compose a thermal pretreatment method where biomass is heated in the temperature range of 150–300 °C in an inert or reduced environment. The process parameters, like torrefaction temperature and residence time, have a significant impact on the proximate, ultimate, and energy properties. In this study, torrefaction experiments were conducted on 2-mm ground lodgepole pine (Pinus contorta using a thermogravimetric analyzer. Both deep drying and torrefaction temperature (160–270 °C and time (15–120 min were selected. Torrefied samples were analyzed for the proximate, ultimate, and higher heating value. The results indicate that moisture content decreases with increases in torrefaction temperature and time, where at 270 °C and 120 min, the moisture content is found to be 1.15% (w.b.. Volatile content in the lodgepole pine decreased from about 80% to about 45%, and ash content increased from 0.77% to about 1.91% at 270 °C and 120 min. The hydrogen, oxygen, and sulfur content decreased to 3%, 28.24%, and 0.01%, whereas the carbon content and higher heating value increased to 68.86% and 23.67 MJ/kg at 270 °C and 120 min. Elemental ratio of hydrogen to carbon and oxygen to carbon (H/C and O/C calculated at 270 °C and a 120-min residence time were about 0.56 and 0.47. Based on this study, it can be concluded that higher torrefaction temperatures ≥230 °C and residence time ≥15 min influence the proximate, ultimate, and energy properties of ground lodgepole pine.

  3. Grind hardening process

    CERN Document Server

    Salonitis, Konstantinos

    2015-01-01

    This book presents the grind-hardening process and the main studies published since it was introduced in 1990s.  The modelling of the various aspects of the process, such as the process forces, temperature profile developed, hardness profiles, residual stresses etc. are described in detail. The book is of interest to the research community working with mathematical modeling and optimization of manufacturing processes.

  4. Efficiency of deep core muscles training on patients with low back pain

    OpenAIRE

    Povilauskaitė, Ieva

    2017-01-01

    Efficiency of Deep Core Muscles Training on Patients with Low Back Pain Vilnius University Faculty of Medicine Department of Rehabilitation, Physical and Sports Medicine Bachelor Degree of Physiotherapy Efficiency of Deep Core Muscles Strengthening Exercises on Patients with Low Back Pain Physiotherapy Bachelor's Thesis The Author: Ieva Povilauskaitė Academic advisor: Lecturer dr. Ieva Eglė Jamontaitė The aim of research work: measure the efficiency of come muscles strengthening exercises in ...

  5. First Grinding of a Rock on Mars

    Science.gov (United States)

    2004-01-01

    The round, shallow depression in this image resulted from history's first grinding of a rock on Mars. The rock abrasion tool on NASA's Spirit rover ground off the surface of a patch 45.5 millimeters (1.8 inches) in diameter on a rock called Adirondack during Spirit's 34th sol on Mars, Feb. 6, 2004. The hole is 2.65 millimeters (0.1 inch) deep, exposing fresh interior material of the rock for close inspection with the rover's microscopic imager and two spectrometers on the robotic arm. This image was taken by Spirit's panoramic camera, providing a quick visual check of the success of the grinding. The rock abrasion tools on both Mars Exploration Rovers were supplied by Honeybee Robotics, New York, N.Y.

  6. Grinding Inside A Toroidal Cavity

    Science.gov (United States)

    Mayer, Walter; Adams, James F.; Burley, Richard K.

    1987-01-01

    Weld lines ground smooth within about 0.001 in. Grinding tool for smoothing longitudinal weld lines inside toroidal cavity includes curved tunnel jig to guide grinding "mouse" along weld line. Curvature of tunnel jig matched to shape of toroid so grinding ball in mouse follows circular arc of correct radius as mouse is pushed along tunnel. Tool enables precise control of grindout shape, yet easy to use.

  7. Highly efficient deep-blue organic light emitting diode with a carbazole based fluorescent emitter

    Science.gov (United States)

    Sahoo, Snehasis; Dubey, Deepak Kumar; Singh, Meenu; Joseph, Vellaichamy; Thomas, K. R. Justin; Jou, Jwo-Huei

    2018-04-01

    High efficiency deep-blue emission is essential to realize energy-saving, high-quality display and lighting applications. We demonstrate here a deep-blue organic light emitting diode using a novel carbazole based fluorescent emitter 7-[4-(diphenylamino)phenyl]-9-(2-ethylhexyl)-9H-carbazole-2-carbonitrile (JV234). The solution processed resultant device shows a maximum luminance above 1,750 cd m-2 and CIE coordinates (0.15,0.06) with a 1.3 lm W-1 power efficiency, 2.0 cd A-1 current efficiency, and 4.1% external quantum efficiency at 100 cd m-2. The resulting deep-blue emission enables a greater than 100% color saturation. The high efficiency may be attributed to the effective host-to-guest energy transfer, suitable device architecture facilitating balanced carrier injection and low doping concentration preventing efficiency roll-off caused by concentration quenching.

  8. Research on operation mode of abrasive grain during grinding

    Science.gov (United States)

    Ivanova, T. N.; Dement’ev, V. B.; Nikitina, O. V.

    2018-03-01

    The processing of materials by cutting with an abrasive tool is carried out by means of thousands of grains bonded together as a single whole. The quality of the abrasive tool is defined by cutting properties of abrasive grains and depends on features of spreading the temperature field in time and in the abrasive grain volume. Grains are exposed to heating and cooling during work. It leads to undesired effects such as a decrease of durability of grain retention in the binder, hardness, intensification of diffusion and oxidation processes between the binder and the grain, the occurrence of considerable temperature stresses in the grain itself. The obtained equation which allows calculation of temperature field of grain for one rotation of grinding wheel shows that the temperature of the wheel depends on grinding modes and thermophysical properties of abrasive material. Thus, as the time of contact of grain with processed material increases, the temperature in the cutting area rises. As thermophysical properties increase, the temperature in cutting area decreases. Thermal working conditions are determined to be different from each other depending on contact time of the grain and the material. For example, in case of creep-feed grinding, the peak value of temperature is higher than during multistep grinding; the depth of expansion is greater. While the speed of the thermal process in creep-feed grinding is 2-3 times lower than in multistep grinding, the gradient reduces 3-4 times. The analysis of machining methods shows that creep-feed grinding ensures greater depth of grain heating, a smaller heating rate and a reduced velocity gradient. It causes a decrease of probable allotropic modifications and prevents from occurring of heat strokes - cracking of grains due to high temperature falls. Consequently, it is necessary to employ creep-feed grinding to increase the efficiency of abrasive tool employing. Three operation modes of grinding wheel including blunting, full

  9. Grinding media of Zr O2-Y2 O3

    International Nuclear Information System (INIS)

    Ussui, V.; Leitao, F.; Paschoal, J.O.A.

    1994-01-01

    This paper describes an experiment carried out to test Yttria 3 mol% stabilized zirconia as a grinding media. The Powders were produced in experimental operations of a wet chemical coprecipitation process at the Zirconium Pilot Plant in IPEN. The stabilised zirconia powders obtained were cold pressed in to cylindrical shapes and sintered at 1500 0 C for hour. The ceramics produced presented good wear resistance and were found to be efficient as zirconia powders grinding media. (author)

  10. Grinding mechanism of zirconia toughened alumina

    International Nuclear Information System (INIS)

    Tsukuda, A.; Kondo, Y.; Yokota, K.

    1998-01-01

    In the grinding process, physical properties of ceramics affect both grinding mechanism and quality of ground surface. In this study we focused on fracture toughness of ceramics and the effect on grinding. A grinding test was carried out by single point grinding for ten different zirconia toughened alumina ceramics with different monoclinic zirconia contents. Effects of zirconia contents on the grinding mechanism and crack initiation were discussed. Copyright (1998) AD-TECH - International Foundation for the Advancement of Technology Ltd

  11. The Influence of Wet Dressing of Grinding Wheel on the Grinding Performance

    OpenAIRE

    重松, 日出見; 冨田, 進

    1989-01-01

    Experiments on the relation between the form of working plane of grinding wheel which was formed by dressing, and the grinding performance of working plane of grinding wheel in the early stage of grinding, were carried out supplying the same grinding fluid in dressing time and grinding time. As a result, it was found that the difference of the action or the effect of grinding fluids on the working plane of grinding fluid were related to the grinding performance in the early stage of grinding....

  12. 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.

  13. DANoC: An Efficient Algorithm and Hardware Codesign of Deep Neural Networks on Chip.

    Science.gov (United States)

    Zhou, Xichuan; Li, Shengli; Tang, Fang; Hu, Shengdong; Lin, Zhi; Zhang, Lei

    2017-07-18

    Deep neural networks (NNs) are the state-of-the-art models for understanding the content of images and videos. However, implementing deep NNs in embedded systems is a challenging task, e.g., a typical deep belief network could exhaust gigabytes of memory and result in bandwidth and computational bottlenecks. To address this challenge, this paper presents an algorithm and hardware codesign for efficient deep neural computation. A hardware-oriented deep learning algorithm, named the deep adaptive network, is proposed to explore the sparsity of neural connections. By adaptively removing the majority of neural connections and robustly representing the reserved connections using binary integers, the proposed algorithm could save up to 99.9% memory utility and computational resources without undermining classification accuracy. An efficient sparse-mapping-memory-based hardware architecture is proposed to fully take advantage of the algorithmic optimization. Different from traditional Von Neumann architecture, the deep-adaptive network on chip (DANoC) brings communication and computation in close proximity to avoid power-hungry parameter transfers between on-board memory and on-chip computational units. Experiments over different image classification benchmarks show that the DANoC system achieves competitively high accuracy and efficiency comparing with the state-of-the-art approaches.

  14. Experimental Setup for Diamond Grinding Using Electrochemical InProcess Controlled Dressing (ECD of Grinding Wheel

    Directory of Open Access Journals (Sweden)

    M. A. Shavva

    2014-01-01

    Full Text Available The most effective method for finish machining of hard-metals and alloys is to use the diamond grinding wheels for grinding. An application of diamond wheels significantly increases the employee output, reduces costs, and raises manufacturing efficiency with achieving the high performance properties of treated surfaces.During grinding a working surface of diamond wheel wears out. It adversely affects the cutting capability of the diamond grains, and depending on the grinding conditions can occur through different mechanisms. Wear of diamond wheel causes distortion of its shape and reduces cutting properties. However, dressing of diamond wheels is a complicated and time-consuming operation in terms of manufacturing technique.Methods to make dressing of diamond grinding wheel have different types of classification. Classification of dressing methods by the type of energy used is as follows: mechanical, chemical, electrophysical, electromechanical, and electrochemical. All these methods have their advantages and disadvantages.Electrochemical method of dressing is the most productive and efficient. Electrochemical method comprises anode-mechanical dressing and electrochemical (electrolytic one. The paper presents the electrochemical in-process dressing (ECD and the electrolytic in-process dressing (ELID.The source of energy, grinding a wheel with metal bond, and an electrode are necessary for providing ELID. The ELID consists of several stages. The first stage is preliminary electrolytic dressing of diamond wheel. The electrolyte is placed into the gap between the wheel and electrode. The bond of the wheel is oxidized. An insulating layer is formed. It reduces an electrical conductivity of the wheel and controls consumption of diamond grains, as well as polishes the surface of the work piece. Further, the insulating layer is destroyed. The cycle of dressing begins anew.The ECD proceeds in the same way as ELID. However during the ECD-process there

  15. Surface topography of parallel grinding process for nonaxisymmetric aspheric lens

    International Nuclear Information System (INIS)

    Zhang Ningning; Wang Zhenzhong; Pan Ri; Wang Chunjin; Guo Yinbiao

    2012-01-01

    Workpiece surface profile, texture and roughness can be predicted by modeling the topography of wheel surface and modeling kinematics of grinding process, which compose an important part of precision grinding process theory. Parallel grinding technology is an important method for nonaxisymmetric aspheric lens machining, but there is few report on relevant simulation. In this paper, a simulation method based on parallel grinding for precision machining of aspheric lens is proposed. The method combines modeling the random surface of wheel and modeling the single grain track based on arc wheel contact points. Then, a mathematical algorithm for surface topography is proposed and applied in conditions of different machining parameters. The consistence between the results of simulation and test proves that the algorithm is correct and efficient. (authors)

  16. Dimethylurea/citric acid as a highly efficient deep eutectic solvent

    Indian Academy of Sciences (India)

    Dimethylurea/citric acid deep eutectic solvent was used as a dual catalyst and a green reaction medium for the efficient synthesis of bis(indolyl)methanes, quinolines and aryl-4, 5-diphenyl-1H-imidazoles. Ease of recovery and reusability of DES with high activity makes this method efficient and eco-friendly.

  17. Effects of hardness of abrasive grains on surface roughness of work piece in PVA bonded grinding wheel

    International Nuclear Information System (INIS)

    Nitta, S.; Takata, A.; Ishizaki, K.

    2000-01-01

    The purpose of this study is to clarify relation between hardness of abrasive grains and surface roughness of work piece in the case of PVA (Polyvinyl alcohol) bonded grinding wheels. Two PVA bonded grinding wheels; with diamond or silicon carbide as abrasive grains and grinding of glass and aluminum alloy was performed. The PVA bonded grinding wheels The PVA bonded grinding wheel with silicon carbide could not grind the glass. Because insufficiency in hardness, the PVA bonded grinding wheel with the diamond abrasive grains caused deep scratch on the aluminum alloy. It was found that the final surface roughness of the work piece was not proportional to the hardness of abrasive grains. The suitable hardness of abrasive grains will be obtained by the hardness of work piece. Copyright (2000) AD-TECH - International Foundation for the Advancement of Technology Ltd

  18. Grinding Si3N4 Powder In Si3N4 Equipment

    Science.gov (United States)

    Herbell, Thomas P.; Freedman, Marc R.; Kiser, James D.

    1989-01-01

    Three methods of grinding compared. Report based on study of grinding silicon nitride powder in preparation for sintering into solid ceramic material. Attrition, vibratory, and ball mills lined with reaction-bonded silicon nitride tested. Rates of reduction of particle sizes and changes in chemical compositions of powders measured so grinding efficiences and increases in impurity contents from wear of mills and media evaluated for each technique.

  19. Deep-blue efficient OLED based on NPB with little efficiency roll-off under high current density

    Science.gov (United States)

    Liu, Jian

    2017-03-01

    NPB usually is used as a hole-transport layer in OLED. In fact, it is a standard pure blue-emission material. However, its light-emitting efficiency in OLED is low due to emissive nature of organic material. Herein, a deep-blue OLDE based on NPB was fabricated. The light-emitting efficiency of the device demonstrates a moderate value, and efficiency roll-off is little under high current density. The device demonstrates that the electroplex's emission decreases with increasing electric field intensity.

  20. AUTOMATION OF IN FEED CENTERLESS GRINDING MACHINE

    OpenAIRE

    Piyusha P. Jadhav*, Sachin V. Lomte, Sudhir Surve

    2017-01-01

    In-feed centerless grinding technique offers a major contribution to the industries. This is the alternative in-feed centerless grinding technique using regulating wheel. Mainly centerless grinding is divided in three types, and those are End feed, in-feed and through feed Centerless grinding. This paper mainly deals with low cost automation on in-feed Centerless grinding machine using regulating wheel suitable for multiple in-feed type jobs. It deals with the development of a Centerless grin...

  1. Efficient fluorescent deep-blue and hybrid white emitting devices based on carbazole/benzimidazole compound

    KAUST Repository

    Yang, Xiaohui

    2011-07-28

    We report the synthesis, photophysics, and electrochemical characterization of carbazole/benzimidazole-based compound (Cz-2pbb) and efficient fluorescent deep-blue light emitting devices based on Cz-2pbb with the peak external quantum efficiency of 4.1% and Commission Internationale dÉnclairage coordinates of (0.16, 0.05). Efficient deep-blue emission as well as high triplet state energy of Cz-2pbb enables fabrication of hybrid white organic light emitting diodes with a single emissive layer. Hybrid white emitting devices based on Cz-2pbb show the peak external quantum efficiency exceeding 10% and power efficiency of 14.8 lm/W at a luminance of 500 cd/m2. © 2011 American Chemical Society.

  2. Grinding in lead-zinc concentrator Sasa – choice between different grinding media

    OpenAIRE

    Krstev, Boris

    2004-01-01

    In this paper will be present result obtained from investigation in the grinding circuit of the lead-zinc concentrator Sasa,using differen grindng media: • Litzkhun-Niederwipper Forged Steel grinding balls; • GSI LUCCHINI Moly-Cop Forged Steel grinding balls; • Cast steel grinding balls from Ukraina and Bulgaria; In the same time will be shown comparation between obtained parameters using different grinding balls specially: • Capacity of the grinding mill; • Particle size; ...

  3. Efficient using of automobile transport for the deep open-pit mines

    OpenAIRE

    Dastan MAHAMBETOV; Bayan RAKISHEV; Galymzhan SAMENOV; Aleksander SŁADKOWSKI

    2013-01-01

    In the paper the method is proposed of substantiation of the major parameters for zones of effective use of automobile transport of different load-carrying capacity by open cast development of the deep deposits. An efficient ratio is determined between the mining and transport equipment by zone-to -zone use.

  4. Control of grinding polygonal surfaces

    Directory of Open Access Journals (Sweden)

    Юрій Володимирович Петраков

    2017-12-01

    Full Text Available Grinding of non-round surfaces, in particular polygonal surfaces of dies, is characterized by substantial non stationary. At different sections of the profile, the change in the main characteristic (Material Removal Rate – MRR process reaches tens of times. To stabilize the grinding process, it is recommended to control the spindle speed of the workpiece CNC grinding machine. Created software that allows to design the control program on the basis of mathematical model of the system. The determination of MRR is realized automatically in the simulation of the grinding process which uses the algorithm developed for solving problems in geometric interaction of the workpiece and the wheel. In forming the control program is possible takes into account the limitations on the maximum circumferential force of cutting, and the maximum allowable acceleration of the machine spindle. Practice has shown that full stabilization is not obtained, even though the performance is increased more than 2 times, while ensuring the quality of the surface. The developed block diagram of the grinding process can serve as a basis for further improvement in the solution of dynamic problems.

  5. Grinding Parts For Automatic Welding

    Science.gov (United States)

    Burley, Richard K.; Hoult, William S.

    1989-01-01

    Rollers guide grinding tool along prospective welding path. Skatelike fixture holds rotary grinder or file for machining large-diameter rings or ring segments in preparation for welding. Operator grasps handles to push rolling fixture along part. Rollers maintain precise dimensional relationship so grinding wheel cuts precise depth. Fixture-mounted grinder machines surface to quality sufficient for automatic welding; manual welding with attendant variations and distortion not necessary. Developed to enable automatic welding of parts, manual welding of which resulted in weld bead permeated with microscopic fissures.

  6. An experimental assessment on the performance of different lubrication techniques in grinding of Inconel 751.

    Science.gov (United States)

    Balan, A S S; Vijayaraghavan, L; Krishnamurthy, R; Kuppan, P; Oyyaravelu, R

    2016-09-01

    The application of emulsion for combined heat extraction and lubrication requires continuous monitoring of the quality of emulsion to sustain a desired grinding environment; this is applicable to other grinding fluids as well. Thus to sustain a controlled grinding environment, it is necessary to adopt an effectively lubricated wheel-work interface. The current study was undertaken to assess experimentally the ​ effects of different grinding environments such as dry, minimum quantity lubrication (MQL) and Cryo-MQL on performance, such as grinding force, temperature, surface roughness and chip morphology on Inconel 751, a higher heat resistance material posing thermal problems and wheel loading. The results show that grinding with the combination of both liquid nitrogen (LN2) and MQL lowers temperature, cutting forces, and surface roughness as compared with MQL and dry grinding. Specific cutting energy is widely used as an inverse measure of process efficiency in machining. It is found from the results that specific cutting energy of Cryo-MQL assisted grinding is 50-65% lower than conventional dry grinding. The grindability of Inconel 751 superalloy can be enhanced with Cryo-MQL condition.

  7. An experimental assessment on the performance of different lubrication techniques in grinding of Inconel 751

    Directory of Open Access Journals (Sweden)

    A.S.S. Balan

    2016-09-01

    Full Text Available The application of emulsion for combined heat extraction and lubrication requires continuous monitoring of the quality of emulsion to sustain a desired grinding environment; this is applicable to other grinding fluids as well. Thus to sustain a controlled grinding environment, it is necessary to adopt an effectively lubricated wheel-work interface. The current study was undertaken to assess experimentally the ​ effects of different grinding environments such as dry, minimum quantity lubrication (MQL and Cryo-MQL on performance, such as grinding force, temperature, surface roughness and chip morphology on Inconel 751, a higher heat resistance material posing thermal problems and wheel loading. The results show that grinding with the combination of both liquid nitrogen (LN2 and MQL lowers temperature, cutting forces, and surface roughness as compared with MQL and dry grinding. Specific cutting energy is widely used as an inverse measure of process efficiency in machining. It is found from the results that specific cutting energy of Cryo-MQL assisted grinding is 50–65% lower than conventional dry grinding. The grindability of Inconel 751 superalloy can be enhanced with Cryo-MQL condition.

  8. Characterisation and management of concrete grinding residuals.

    Science.gov (United States)

    Kluge, Matt; Gupta, Nautasha; Watts, Ben; Chadik, Paul A; Ferraro, Christopher; Townsend, Timothy G

    2018-02-01

    Concrete grinding residue is the waste product resulting from the grinding, cutting, and resurfacing of concrete pavement. Potential beneficial applications for concrete grinding residue include use as a soil amendment and as a construction material, including as an additive to Portland cement concrete. Concrete grinding residue exhibits a high pH, and though not hazardous, it is sufficiently elevated that precautions need to be taken around aquatic ecosystems. Best management practices and state regulations focus on reducing the impact on such aquatic environment. Heavy metals are present in concrete grinding residue, but concentrations are of the same magnitude as typically recycled concrete residuals. The chemical composition of concrete grinding residue makes it a useful product for some soil amendment purposes at appropriate land application rates. The presence of unreacted concrete in concrete grinding residue was examined for potential use as partial replacement of cement in new concrete. Testing of Florida concrete grinding residue revealed no dramatic reactivity or improvement in mortar strength.

  9. Bruxism (Teeth Grinding or Clenching) (For Parents)

    Science.gov (United States)

    ... Staying Safe Videos for Educators Search English Español Bruxism (Teeth Grinding or Clenching) KidsHealth / For Parents / Bruxism ( ... called bruxism , which is common in kids. About Bruxism Bruxism is the medical term for the grinding ...

  10. Steel grinding media in production use

    International Nuclear Information System (INIS)

    Nass, D.E.

    1975-01-01

    This paper reviews the types of steel being used for grinding rods and balls by the mining industry in U. S. and Canada. Results of a Dec. 1973 grinding media survey of U. S. and Canadian mills are summarized. Common alloying elements (C, Mn, Cr, Mo, Cu, etc.) are discussed. Grinding balls and rods are discussed separately; wear tests using irradiated balls are described. Finally, defects in grinding media are discussed

  11. Operating results of Kosmos Cement's O-SEPA separator for raw grinding

    Energy Technology Data Exchange (ETDEWEB)

    Ireland, T C [Consultec Ltd., Toronto (CA); Schultz, G K [Southdown Incorporated, Houston, TX (US)

    1991-01-01

    High efficiency separators were first introduced in the cement industry to improve the energy efficiency of finish grinding circuits. Lately, however, a great deal of interest has been focused on improving the energy efficiency of raw grinding circuits. High efficiency separators have successfully been installed in roller mills as well as in ball mill raw grinding circuits. This paper describes the operating experience of the first installation in North America using a high efficiency separator in a raw grinding circuit. This installation, commissioned in 1988 at the Louisville, Kentucky plant of Kosmos Cement, uses a conventional 4500 HP ball mill and a high efficiency dynamic separator to produce raw meal for a preheater kiln as well as high fineness limestone for sulphur scrubbing in a nearby power plant. The system uses kiln exhaust gases for drying both in the mill and in the separator. (author).

  12. Ceramic-bonded abrasive grinding tools

    Science.gov (United States)

    Holcombe, Jr., Cressie E.; Gorin, Andrew H.; Seals, Roland D.

    1994-01-01

    Abrasive grains such as boron carbide, silicon carbide, alumina, diamond, cubic boron nitride, and mullite are combined with a cement primarily comprised of zinc oxide and a reactive liquid setting agent and solidified into abrasive grinding tools. Such grinding tools are particularly suitable for grinding and polishing stone, such as marble and granite.

  13. Ceramic-bonded abrasive grinding tools

    Science.gov (United States)

    Holcombe, C.E. Jr.; Gorin, A.H.; Seals, R.D.

    1994-11-22

    Abrasive grains such as boron carbide, silicon carbide, alumina, diamond, cubic boron nitride, and mullite are combined with a cement primarily comprised of zinc oxide and a reactive liquid setting agent and solidified into abrasive grinding tools. Such grinding tools are particularly suitable for grinding and polishing stone, such as marble and granite.

  14. Investigation of glycerol polymerization in the clinker grinding process

    NARCIS (Netherlands)

    Parvulescu, A.N.; Rossi, M.; Della Pina, C.; Ciriminna, R.; Pagliaro, M.

    2011-01-01

    Concrete production is a large scale process that involves high energy consumption. In order to increase the sustainability of this process, the reduction of energy input is necessary. Bio-glycerol was demonstrated to be a highly efficient renewable-based additive in the grinding process for

  15. Evaluation of minimum quantity lubrication grinding with nano-particles and recent related patents.

    Science.gov (United States)

    Li, Changhe; Wang, Sheng; Zhang, Qiang; Jia, Dongzhou

    2013-06-01

    In recent years, a large number of patents have been devoted to developing minimum quantity lubrication (MQL) grinding techniques that can significantly improve both environmentally conscious and energy saving and costeffective sustainable grinding fluid alternatives. Among them, one patent is about a supply system for the grinding fluid in nano-particle jet MQL, which produced MQL lubricant by adding solid nano-particles in degradable grinding fluid. The MQL supply device turns the lubricant to the pulse drops with fixed pressure, unchanged pulse frequency and the same drop diameter. The drops will be produced and injected in the grinding zone in the form of jet flow under high pressure gas and air seal. As people become increasingly demanding on our environment, minimum quantity lubrication has been widely used in the grinding and processing. Yet, it presents the defect of insufficient cooling performance, which confines its development. To improve the heat transfer efficiency of MQL, nano-particles of a certain mass fraction can be added in the minimum quantity of lubricant oil, which concomitantly will improve the lubrication effects in the processing. In this study, the grinding experiment corroborated the effect of nano-particles in surface grinding. In addition, compared with other forms of lubrication, the results presented that the grinding force, the friction coefficient and specific grinding energy of MQL grinding have been significantly weakened, while G ratio greatly rose. These are attributed to the friction oil-film with excellent anti-friction and anti-wear performance, which is generated nano-particles at the wheel/workpiece interface. In this research, the cooling performance of nano-particle jet MQL was analyzed. Based on tests and experiments, the surface temperature was assayed from different methods, including flood lubricating oil, dry grinding, MQL grinding and nano-particle jet MQL grinding. Because of the outstanding heat transfer

  16. Research on Grinding and Polishing Force Control of Compliant Flange

    Directory of Open Access Journals (Sweden)

    Li Chuang

    2015-01-01

    Full Text Available The automation of the grinding and polishing process is important to improve the production efficiency of the part surfaces. In this paper, a new compliant flange mounted on the end of the industrial robots for the robotic grinding and polishing force control is developed. With regard to the non-linear and time-varying problem of the contact force, the mathematical model of the new force control system was presented and the fuzzy PID control strategy was used to drive the proposed system. Especially, the air spring and electric proportional valve is studied to establish the model. The simulation results show that the selected control strategy has quick response and good robustness, which satisfies the real-time requirements of the grinding and polishing force control in processing.

  17. "Grinding" cavities in polyurethane foam

    Science.gov (United States)

    Brower, J. R.; Davey, R. E.; Dixon, W. F.; Robb, P. H.; Zebus, P. P.

    1980-01-01

    Grinding tool installed on conventional milling machine cuts precise cavities in foam blocks. Method is well suited for prototype or midsize production runs and can be adapted to computer control for mass production. Method saves time and materials compared to bonding or hot wire techniques.

  18. Synthesis of high efficient Cu/TiO{sub 2} photocatalysts by grinding and their size-dependent photocatalytic hydrogen production

    Energy Technology Data Exchange (ETDEWEB)

    Ni, Dawei; Shen, Haiyan; Li, Huiqiao; Ma, Ying; Zhai, Tianyou, E-mail: yingma@hust.edu.cn

    2017-07-01

    Highlights: • Cu nanodots were decorated on TiO{sub 2} surface through ball milling method. • Its size distribution was investigated in water and ethanolic medium. • Photocurrent response and hydrogen evolution was improved. • Performance was found to be dependent on size of Cu nanodots. - Abstract: Recently, copper species have been extensively investigated to replace Pt as efficient co-catalysts for the evolution of H{sub 2} due to their low cost and relatively high activity. Cu nanoparticles less than 5 nm are successfully decorated on TiO{sub 2} surface in this work by an easy and mild milling process. These Cu nanoparticles are highly dispersed on TiO{sub 2} when the loading amount of Cu is no more than 10 wt%. The sizes of Cu nanoparticles can be controlled by changing the milling environment and decrease in the order of Cu-ethanol > Cu-water > Cu nanoparticles obtained through drying milling. The highest and stable hydrogen generation can be realized on Cu/TiO{sub 2} with 2.0 wt% Cu and sizes of Cu nanoparticles ranging from 2 to 4 nm, in which high and stable photocurrent confirms promoted photogenerated charge separation. Smaller Cu clusters are demonstrated to be detrimental to hydrogen evolution at same Cu content. High loading of Cu nanoparticles of 2–4 nm will benefit photogenerated electron-hole recombination and thus decrease the activity of Cu/TiO{sub 2}. The results here demonstrate the key roles of Cu cluster size in addition to Cu coverage on photocatalytic activity of Cu/TiO{sub 2} composite photocatalysts.

  19. The efficient future of deep-space travel - electric rockets; Das Zeitalter der Elektrischen Raketen

    Energy Technology Data Exchange (ETDEWEB)

    Choueiri, Edgar Y. [Princeton Univ., NJ (United States). Electric Propulsion and Plasma Dynamics Lab.

    2010-01-15

    Conventional rockets generate thrust by burning chemical fuel. Electric rockets propel space vehicles by applying electric or electromagnetic fields to clouds of charged particles, or plasmas, to accelerate them. Although electric rockets offer much lower thrust levels than their chemical cousins, they can eventually enable spacecraft to reach greater speeds for the same amount of propellant. Electric rockets' high-speed capabilities and their efficient use of propellant make them valuable for deep-space missions. (orig.)

  20. DLTAP: A Network-efficient Scheduling Method for Distributed Deep Learning Workload in Containerized Cluster Environment

    OpenAIRE

    Qiao Wei; Li Ying; Wu Zhong-Hai

    2017-01-01

    Deep neural networks (DNNs) have recently yielded strong results on a range of applications. Training these DNNs using a cluster of commodity machines is a promising approach since training is time consuming and compute-intensive. Furthermore, putting DNN tasks into containers of clusters would enable broader and easier deployment of DNN-based algorithms. Toward this end, this paper addresses the problem of scheduling DNN tasks in the containerized cluster environment. Efficiently scheduling ...

  1. Novel CNC Grinding Process Control for Nanometric Surface Roughness for Aspheric Space Optical Surfaces

    Directory of Open Access Journals (Sweden)

    Jeong-Yeol Han

    2004-06-01

    Full Text Available Optics fabrication process for precision space optical parts includes bound abrasive grinding, loose abrasive lapping and polishing. The traditional bound abrasive grinding with bronze bond cupped diamond wheel leaves the machine marks of about 20 μm rms in height and the subsurface damage of about 1 μm rms in height to be removed by subsequent loose abrasive lapping. We explored an efficient quantitative control of precision CNC grinding. The machining parameters such as grain size, work-piece rotation speed and feed rate were altered while grinding the work-piece surfaces of 20-100 mm in diameter. The input grinding variables and the resulting surface quality data were used to build grinding prediction models using empirical and multi-variable regression analysis. The effectiveness of such grinding prediction models was then examined by running a series of precision CNC grinding operation with a set of controlled input variables and predicted output surface quality indicators. The experiment achieved the predictability down to ±20 nm in height and the surface roughness down to 36 nm in height. This study contributed to improvement of the process efficiency reaching directly the polishing and figuring process without the need for the loose abrasive lapping stage.

  2. Surface grinding of intermetallic titanium aluminides

    CERN Document Server

    Gröning, Holger Andreas

    2014-01-01

    A deductive kinematic model of creep-feed and speed-stroke grinding processes is developed to identify possibilities to reduce the energy introduced into the workpiece. By computer tomography analysis and tactile measurements of the grinding wheel the pore volume and the static cutting edge number are determined and included in the model. Based on the kinematic model and the grinding wheel characteristics an analytical evaluation of the specific grinding energy for speed-stroke and creep-feed grinding is carried out. The deducted process design is evaluated in experimental investigations. The

  3. Force characteristics in continuous path controlled crankpin grinding

    Science.gov (United States)

    Zhang, Manchao; Yao, Zhenqiang

    2015-03-01

    Recent research on the grinding force involved in cylindrical plunge grinding has focused mainly on steady-state conditions. Unlike in conventional external cylindrical plunge grinding, the conditions between the grinding wheel and the crankpin change periodically in path controlled grinding because of the eccentricity of the crankpin and the constant rotational speed of the crankshaft. The objective of this study is to investigate the effects of various grinding conditions on the characteristics of the grinding force during continuous path controlled grinding. Path controlled plunge grinding is conducted at a constant rotational speed using a cubic boron nitride (CBN) wheel. The grinding force is determined by measuring the torque. The experimental results show that the force and torque vary sinusoidally during dry grinding and load grinding. The variations in the results reveal that the resultant grinding force and torque decrease with higher grinding speeds and increase with higher peripheral speeds of the pin and higher grinding depths. In path controlled grinding, unlike in conventional external cylindrical plunge grinding, the axial grinding force cannot be disregarded. The speeds and speed ratios of the workpiece and wheel are also analyzed, and the analysis results show that up-grinding and down-grinding occur during the grinding process. This paper proposes a method for describing the force behavior under varied process conditions during continuous path controlled grinding, which provides a beneficial reference for describing the material removal mechanism and for optimizing continuous controlled crankpin grinding.

  4. Staged Inference using Conditional Deep Learning for energy efficient real-time smart diagnosis.

    Science.gov (United States)

    Parsa, Maryam; Panda, Priyadarshini; Sen, Shreyas; Roy, Kaushik

    2017-07-01

    Recent progress in biosensor technology and wearable devices has created a formidable opportunity for remote healthcare monitoring systems as well as real-time diagnosis and disease prevention. The use of data mining techniques is indispensable for analysis of the large pool of data generated by the wearable devices. Deep learning is among the promising methods for analyzing such data for healthcare applications and disease diagnosis. However, the conventional deep neural networks are computationally intensive and it is impractical to use them in real-time diagnosis with low-powered on-body devices. We propose Staged Inference using Conditional Deep Learning (SICDL), as an energy efficient approach for creating healthcare monitoring systems. For smart diagnostics, we observe that all diagnoses are not equally challenging. The proposed approach thus decomposes the diagnoses into preliminary analysis (such as healthy vs unhealthy) and detailed analysis (such as identifying the specific type of cardio disease). The preliminary diagnosis is conducted real-time with a low complexity neural network realized on the resource-constrained on-body device. The detailed diagnosis requires a larger network that is implemented remotely in cloud and is conditionally activated only for detailed diagnosis (unhealthy individuals). We evaluated the proposed approach using available physiological sensor data from Physionet databases, and achieved 38% energy reduction in comparison to the conventional deep learning approach.

  5. Deep features for efficient multi-biometric recognition with face and ear images

    Science.gov (United States)

    Omara, Ibrahim; Xiao, Gang; Amrani, Moussa; Yan, Zifei; Zuo, Wangmeng

    2017-07-01

    Recently, multimodal biometric systems have received considerable research interest in many applications especially in the fields of security. Multimodal systems can increase the resistance to spoof attacks, provide more details and flexibility, and lead to better performance and lower error rate. In this paper, we present a multimodal biometric system based on face and ear, and propose how to exploit the extracted deep features from Convolutional Neural Networks (CNNs) on the face and ear images to introduce more powerful discriminative features and robust representation ability for them. First, the deep features for face and ear images are extracted based on VGG-M Net. Second, the extracted deep features are fused by using a traditional concatenation and a Discriminant Correlation Analysis (DCA) algorithm. Third, multiclass support vector machine is adopted for matching and classification. The experimental results show that the proposed multimodal system based on deep features is efficient and achieves a promising recognition rate up to 100 % by using face and ear. In addition, the results indicate that the fusion based on DCA is superior to traditional fusion.

  6. Efficient, deep-blue TADF-emitters for OLED display applications (Conference Presentation)

    Science.gov (United States)

    Volz, Daniel; Baumann, Thomas

    2016-09-01

    Currently, the mobile display market is strongly shifting towards AMOLED technology, in order to enable curved and flexible displays. This leads to a growing demand for highly efficient OLED emitters to reduce the power consumption and increase display resolution at the same time. While highly efficient green and red OLEDs already found their place in commercial OLED-displays, the lack of efficient blue emitters is still an issue. Consequently, the active area for blue is considerably larger than for green and red pixels, to make up for the lower efficiency. We intend to close this efficiency-gap with novel emitters based on thermally activated delayed fluorescence (TADF) technology. Compared to state-of-the-art fluorescent dopants, the efficiency of TADF-emitters is up to four times higher. At the same time, it is possible to design them in a way to maintain deep blue emission, i.e. CIE y < 0.2. These aspects are relevant to produce efficient high resolution AMOLED displays. Apart from these direct customer benefits, our TADF technology does not contain any rare elements, which allows for the fabrication of sustainable OLED technology. In this work, we highlight one of our recently developed blue TADF materials. Basic material properties as well as first device results are discussed. In a bottom-emitting device, a CIEx/CIEy coordinate of (0.16/0.17) was achieved with efficiency values close to 20% EQE.

  7. Work Index and Grinding Energy Assessment of Dilband Iron Ore, Pakistan

    Directory of Open Access Journals (Sweden)

    Muhammad Ishaque Abro

    2011-01-01

    Full Text Available Importance of comminution in mineral processing sector is highly acknowledged from energy perspective. In present study an attempt was made to understand the comminuting behavior of Dilband iron ore and to compute the grinding energy requirement for production of ultrafine particles up to mesh of liberation. In this regard standard grindability tests developed by the Chair of Mineral Processing Leoben Austria was used for calculating work index of Dilband iron ore. The grinding tests were conducted in rod and ball mills. The work index value of two feed size fractions with 80% passing at 3800?m and 5200?m was noted to be 11.85 kwh/t and 9.3 kwh/ton respectively. Ball mill grinding test indicates that dry grinding in open circuit is not efficient and consumes more energy of 88.48kwh/t of ore for grinding 1000/40?m to 80% <40?m size.

  8. Surface grinding characteristics of ferrous metals under high-speed and speed-stroke grinding conditions

    International Nuclear Information System (INIS)

    Ghani, A.K.; Choudhury, I.A.; Ahim, M.B.

    1999-01-01

    Some ferrous metals have been ground under different conditions with high-speed and speed-stroke in surface grinding operation. The paper describes experimental investigation of grinding forces in grinding some ferrous metals with the application of cutting fluids. Grinding tests have been carried out on mild steel, assab steel and stainless steel with different combinations of down feed and cross feed. The wheel speed was 27 m/sec while the table speed was maintained at the maximum possible 25 m/min. The grindability has been evaluated by measuring the grinding forces, grinding ratio, and surface finish. Grinding forces have been plotted against down feed of the grinding wheel and cross feed of the table. It has been observed that the radial and tangential grinding forces in stainless steel were higher than those in assab steel and mild steel

  9. Grinding assembly, grinding apparatus, weld joint defect repair system, and methods

    Science.gov (United States)

    Larsen, Eric D.; Watkins, Arthur D.; Bitsoi, Rodney J.; Pace, David P.

    2005-09-27

    A grinding assembly for grinding a weld joint of a workpiece includes a grinder apparatus, a grinder apparatus includes a grinding wheel configured to grind the weld joint, a member configured to receive the grinding wheel, the member being configured to be removably attached to the grinder apparatus, and a sensor assembly configured to detect a contact between the grinding wheel and the workpiece. The grinding assembly also includes a processing circuitry in communication with the grinder apparatus and configured to control operations of the grinder apparatus, the processing circuitry configured to receive weld defect information of the weld joint from an inspection assembly to create a contour grinding profile to grind the weld joint in a predetermined shape based on the received weld defect information, and a manipulator having an end configured to carry the grinder apparatus, the manipulator further configured to operate in multiple dimensions.

  10. Experiment research on grind-hardening of AISI5140 steel based on thermal copensation

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Xiang Ming; Ren, Ying Hui; Zheng, Bo; Zhou, Zhixiong [College of Mechanical and Vehicle Engineering, Hunan University, Changsha, Hunan (China); Deng, Zhao Hui [Key Laboratory for High Efficiency and Precision Machining of Difficult-to-Cut Material of Hunan Province, Hunan (China)

    2016-08-15

    The grind-hardening process utilizes the heat generated to induce martensitic phase transformation. However, the maximum achievable harden layer depth is limited due to high grinding forces, and the tensile residual stress appears on the ground surface in the grind-hardening process. This paper proposes a new grind-hardening technology using thermal compensation. The workpiece of AISI5140 steel is preheated by electric resistance heating, and ground under the condition of the workpiece temperature 25°C, 120°C, 180°C and 240°C. The grinding force, harden layer depth and surface quality including residual stress on ground surface, surface roughness and micro-hardness are investigated. The experimental results show that a deep harden layer with a fine grain martensite can be obtained with the thermal compensation. The ground workpiece surface produces a certain compressive residual stress, and the residual compressive stress value increases with preheating temperature. As the preheating temperature increases, grinding force slightly decreases, while there is slightly increment of surface roughness. Compared with the conventional grind-hardening process, both the harden layer depth and residual stress distribution are significantly improved.

  11. Representation learning with deep extreme learning machines for efficient image set classification

    KAUST Repository

    Uzair, Muhammad

    2016-12-09

    Efficient and accurate representation of a collection of images, that belong to the same class, is a major research challenge for practical image set classification. Existing methods either make prior assumptions about the data structure, or perform heavy computations to learn structure from the data itself. In this paper, we propose an efficient image set representation that does not make any prior assumptions about the structure of the underlying data. We learn the nonlinear structure of image sets with deep extreme learning machines that are very efficient and generalize well even on a limited number of training samples. Extensive experiments on a broad range of public datasets for image set classification show that the proposed algorithm consistently outperforms state-of-the-art image set classification methods both in terms of speed and accuracy.

  12. Representation learning with deep extreme learning machines for efficient image set classification

    KAUST Repository

    Uzair, Muhammad; Shafait, Faisal; Ghanem, Bernard; Mian, Ajmal

    2016-01-01

    Efficient and accurate representation of a collection of images, that belong to the same class, is a major research challenge for practical image set classification. Existing methods either make prior assumptions about the data structure, or perform heavy computations to learn structure from the data itself. In this paper, we propose an efficient image set representation that does not make any prior assumptions about the structure of the underlying data. We learn the nonlinear structure of image sets with deep extreme learning machines that are very efficient and generalize well even on a limited number of training samples. Extensive experiments on a broad range of public datasets for image set classification show that the proposed algorithm consistently outperforms state-of-the-art image set classification methods both in terms of speed and accuracy.

  13. The Effects of Wear upon the Axial Profile of a Grinding Wheel in the Construction of Innovative Grinding Wheels for Internal Cylindrical Grinding

    OpenAIRE

    Nadolny, K.; Słowiński, B.

    2011-01-01

    The article describes the effects of wear upon the axial profile of a grinding wheel in the axial cylindrical grinding processes. This mechanism was used to develop a grinding wheel with zone diversified structure made of microcrystalline sintered corundum abrasive grains and vitrifies bond. Such a grinding wheel is characterized by the conical rough grinding zone that is made by grains of a relatively large size, and a cylindrical finish grinding zone with grains of a smaller size and can be...

  14. Prime costs and economic efficiency of deep drilling in Chechen-Ingush ASSR

    Energy Technology Data Exchange (ETDEWEB)

    Umanskii, L.M.

    1982-04-01

    The possibilities of reducing the prime costs of deep well drilling and improving the efficiency of drilling are considered. The dynamics of performance over the last two five-year plan (FYP) periods is analyzed and it is shown that the performance in the 10th FYP did not improve as compared to the 9th FYP. This is due to geological conditions and shortcomings in the technology and organization of drilling. It is shown that the speed and depth of drilling are decisive factors influencing costs.

  15. 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.

  16. Grinding arrangement for ball nose milling cutters

    Science.gov (United States)

    Burch, C. F. (Inventor)

    1974-01-01

    A grinding arrangement for spiral fluted ball nose end mills and like tools includes a tool holder for positioning the tool relative to a grinding wheel. The tool is mounted in a spindle within the tool holder for rotation about its centerline and the tool holder is pivotably mounted for angular movement about an axis which intersects that centerline. A follower arm of a cam follower secured to the spindle cooperates with a specially shaped cam to provide rotation of the tool during the angular movement of the tool holder during the grinding cycle, by an amount determined by the cam profile. In this way the surface of the cutting edge in contact with the grinding wheel is maintained at the same height on the grinding wheel throughout the angular movement of the tool holder during the grinding cycle.

  17. The grinding of uranium dioxide from fluidized beds; Estudio del m icronizado del UO{sub 2} procedente de lechos Fluidizados

    Energy Technology Data Exchange (ETDEWEB)

    Alonso Folgueras, J A

    1974-07-01

    This work deals with the UO{sub 2} vibratory grinding, the UO{sub 2} obtained from fluidized beds. In this study the grinding time has been correlated with surface area, stoichiometry, granulometry and grinded product contamination. The efficiency losses in the grinding of moisten UO{sub 2} are outlined. Finally it is made a brief study of the granulate obtained from the grinded UO{sub 2} as well as the green pellets resulting from it, taking into consideration the dispersion of its density and height. (Author)

  18. Grinding Parameter Optimization of Ultrasound-Aided Electrolytic in Process Dressing for Finishing Nanocomposite Ceramics

    Directory of Open Access Journals (Sweden)

    Fan Chen

    2016-01-01

    Full Text Available In order to achieve the precision and efficient processing of nanocomposite ceramics, the ultrasound-aided electrolytic in process dressing method was proposed. But how to realize grinding parameter optimization, that is, the maximum processing efficiency, on the premise of the assurance of best workpiece quality is a problem that needs to be solved urgently. Firstly, this research investigated the influence of grinding parameters on material removal rate and critical ductile depth, and their mathematic models based on the existing models were developed to simulate the material removal process. Then, on the basis of parameter sensitivity analysis based on partial derivative, the sensitivity models of material removal rates on grinding parameter were established and computed quantitatively by MATLAB, and the key grinding parameter for optimal grinding process was found. Finally, the theoretical analyses were verified by experiments: the material removal rate increases with the increase of grinding parameters, including grinding depth (ap, axial feeding speed (fa, workpiece speed (Vw, and wheel speed (Vs; the parameter sensitivity of material removal rate was in a descending order as ap>fa>Vw>Vs; the most sensitive parameter (ap was optimized and it was found that the better machining result has been obtained when ap was about 3.73 μm.

  19. Specific grinding energy and surface roughness of nanoparticle jet minimum quantity lubrication in grinding

    Directory of Open Access Journals (Sweden)

    Zhang Dongkun

    2015-04-01

    Full Text Available Nanoparticles with the anti-wear and friction reducing features were applied as cooling lubricant in the grinding fluid. Dry grinding, flood grinding, minimal quantity of lubrication (MQL, and nanoparticle jet MQL were used in the grinding experiments. The specific grinding energy of dry grinding, flood grinding and MQL were 84, 29.8, 45.5 J/mm3, respectively. The specific grinding energy significantly decreased to 32.7 J/mm3 in nanoparticle MQL. Compared with dry grinding, the surface roughness values of flood grinding, MQL, and nanoparticle jet MQL were significantly reduced with the surface topography profile values reduced by 11%, 2.5%, and 10%, respectively, and the ten point height of microcosmic unflatness values reduced by 1.5%, 0.5%, and 1.3%, respectively. These results verified the satisfactory lubrication effects of nanoparticle MQL. MoS2, carbon nanotube (CNT, and ZrO2 nanoparticles were also added in the grinding fluid of nanoparticle jet MQL to analyze their grinding surface lubrication effects. The specific grinding energy of MoS2 nanoparticle was only 32.7 J/mm3, which was 8.22% and 10.39% lower than those of the other two nanoparticles. Moreover, the surface roughness of workpiece was also smaller with MoS2 nanoparticle, which indicated its remarkable lubrication effects. Furthermore, the role of MoS2 particles in the grinding surface lubrication at different nanoparticle volume concentrations was analyzed. MoS2 volume concentrations of 1%, 2%, and 3% were used. Experimental results revealed that the specific grinding energy and the workpiece surface roughness initially increased and then decreased as MoS2 nanoparticle volume concentration increased. Satisfactory grinding surface lubrication effects were obtained with 2% MoS2 nanoparticle volume concentration.

  20. Conversion of Continuous-Valued Deep Networks to Efficient Event-Driven Networks for Image Classification.

    Science.gov (United States)

    Rueckauer, Bodo; Lungu, Iulia-Alexandra; Hu, Yuhuang; Pfeiffer, Michael; Liu, Shih-Chii

    2017-01-01

    Spiking neural networks (SNNs) can potentially offer an efficient way of doing inference because the neurons in the networks are sparsely activated and computations are event-driven. Previous work showed that simple continuous-valued deep Convolutional Neural Networks (CNNs) can be converted into accurate spiking equivalents. These networks did not include certain common operations such as max-pooling, softmax, batch-normalization and Inception-modules. This paper presents spiking equivalents of these operations therefore allowing conversion of nearly arbitrary CNN architectures. We show conversion of popular CNN architectures, including VGG-16 and Inception-v3, into SNNs that produce the best results reported to date on MNIST, CIFAR-10 and the challenging ImageNet dataset. SNNs can trade off classification error rate against the number of available operations whereas deep continuous-valued neural networks require a fixed number of operations to achieve their classification error rate. From the examples of LeNet for MNIST and BinaryNet for CIFAR-10, we show that with an increase in error rate of a few percentage points, the SNNs can achieve more than 2x reductions in operations compared to the original CNNs. This highlights the potential of SNNs in particular when deployed on power-efficient neuromorphic spiking neuron chips, for use in embedded applications.

  1. Conversion of Continuous-Valued Deep Networks to Efficient Event-Driven Networks for Image Classification

    Directory of Open Access Journals (Sweden)

    Bodo Rueckauer

    2017-12-01

    Full Text Available Spiking neural networks (SNNs can potentially offer an efficient way of doing inference because the neurons in the networks are sparsely activated and computations are event-driven. Previous work showed that simple continuous-valued deep Convolutional Neural Networks (CNNs can be converted into accurate spiking equivalents. These networks did not include certain common operations such as max-pooling, softmax, batch-normalization and Inception-modules. This paper presents spiking equivalents of these operations therefore allowing conversion of nearly arbitrary CNN architectures. We show conversion of popular CNN architectures, including VGG-16 and Inception-v3, into SNNs that produce the best results reported to date on MNIST, CIFAR-10 and the challenging ImageNet dataset. SNNs can trade off classification error rate against the number of available operations whereas deep continuous-valued neural networks require a fixed number of operations to achieve their classification error rate. From the examples of LeNet for MNIST and BinaryNet for CIFAR-10, we show that with an increase in error rate of a few percentage points, the SNNs can achieve more than 2x reductions in operations compared to the original CNNs. This highlights the potential of SNNs in particular when deployed on power-efficient neuromorphic spiking neuron chips, for use in embedded applications.

  2. Spatial walk-off compensated beta-barium borate stack for efficient deep-UV generation

    Science.gov (United States)

    Li, Da; Lee, Huai-Chuan; Meissner, Stephanie K.; Meissner, Helmuth E.

    2018-02-01

    Beta-Barium Borate (β-BBO) crystal is commonly used in nonlinear frequency conversion from visible to deep ultraviolet (DUV). However, in a single crystal BBO, its large spatial walk-off effect will reduce spatial overlap of ordinary and extraordinary beam, and thus degrade the conversion efficiency. To overcome the restrictions in current DUV conversion systems, Onyx applies adhesive-free bonding technique to replace the single crystal BBO with a spatial Walk-off Compensated (WOC) BBO stack, which is capable of correcting the spatial walk-off while retaining a constant nonlinear coefficient in the adjacent bonding layers. As a result, the β-BBO stack will provide good beam quality, high conversion efficiency, and broader acceptance angle and spectral linewidth, when compared with a single crystal of BBO. In this work, we report on performance of a spatial walk-off compensated β-BBO stack with adhesive-free bonding technique, for efficiently converting from the visible to DUV range. The physics behind the WOC BBO stack are demonstrated, followed by simulation of DUV conversion efficiency in an external resonance cavity. We also demonstrate experimentally the beam quality improvement in a 4-layer WOC BBO stack over a single BBO crystal.

  3. Advances and patents about grinding equipments with nano-particle jet minimum quantity lubrication.

    Science.gov (United States)

    Jia, Dongzhou; Li, Changhe; Wang, Sheng; Zhang, Qiang; Hou, Yali

    2014-01-01

    In recent years, a large number of patents have been devoted to developing minimum quantity lubrication (MQL) grinding techniques that can significantly improve both environmentally conscious and energy saving and costeffective sustainable grinding fluid alternatives. Among them, one patent is about a controllable nano-fluids jet MQL grinding system based on electrostatic atomization. Using the principle of electrostatics, it can achieve the control of droplet transfer by charging the sprayed droplets. This system can improve the uniformity of the droplet spectrum, liquid deposition efficiency and effective utilization of liquid. It can also effectively control the movement patterns of the droplets, thereby reducing the pollution of the environment and providing better health protection for workers. Although researchers accomplished profound and systematic studies on MQL, especially on nano-particles jet MQL. It can solve the shortage of MQL in cooling performance, greatly improve the working environment, save energy and reduce costs to achieve a low-carbon manufacturing. The unique lubricating performance and tribological property of solid nano-particles form nano-particle shearing films at the grinding wheel/workpiece interface, which can enhance the lubricating performance of MQL grinding. Existing studies on MQL grinding equipments, however, cannot meet the needs of the technological development. Therefore, our research provided a general introduction of the latest patients and research progress of nanoparticles jet MQL grinding equipments presented by the research team from Qingdao Technological University.

  4. Grinding Characteristics Of Directionally Aligned SiC Whisker Wheel-Comparison With Al2O3 Fiber Wheel

    Institute of Scientific and Technical Information of China (English)

    魏源迁; 山口胜美; 菊泽贤二; 洞口严; 中根正喜

    2003-01-01

    A unique SiC whisker wheel was invented,in which the whiskers were aligned normally to the grinding wheel surface.In this paper,grindabilities of the SiC whisker wheel are investigated and compared with those of other wheels of SiC grains,Al2O3 grains,as well as Al2O3 long and short fibres which were also aligned normally to the grinding wheel surface,respectively.The main research contents concern grinding characteristics of a directionally aligned SiC whisker wheel such as material-removal volume,wheel-wear rates,integrity of the ground surfaces,grinding ratios and grinding efficiency.Furthermore,grinding wheels of whiskers and fibres have a common disadvantage:they tend to load easily.The authors have proposed a simple method of loading-free grinding to overcome this propensity and investigate some related grinding characteristics under loading-free grinding conditions.

  5. Developing a trend prediction model of subsurface damage for fixed-abrasive grinding of optics by cup wheels.

    Science.gov (United States)

    Dong, Zhichao; Cheng, Haobo

    2016-11-10

    Fixed-abrasive grinding by cup wheels plays an important role in the production of precision optics. During cup wheel grinding, we strive for a large removal rate while maintaining fine integrity on the surface and subsurface layers (academically recognized as surface roughness and subsurface damage, respectively). This study develops a theoretical model used to predict the trend of subsurface damage of optics (with respect to various grinding parameters) in fixed-abrasive grinding by cup wheels. It is derived from the maximum undeformed chip thickness model, and it successfully correlates the pivotal parameters of cup wheel grinding with the subsurface damage depth. The efficiency of this model is then demonstrated by a set of experiments performed on a cup wheel grinding machine. In these experiments, the characteristics of subsurface damage are inspected by a wedge-polishing plus microscopic inspection method, revealing that the subsurface damage induced in cup wheel grinding is composed of craterlike morphologies and slender cracks, with depth ranging from ∼6.2 to ∼13.2  μm under the specified grinding parameters. With the help of the proposed model, an optimized grinding strategy is suggested for realizing fine subsurface integrity as well as high removal rate, which can alleviate the workload of subsequent lapping and polishing.

  6. Lathe converted for grinding aspheric surfaces

    Science.gov (United States)

    Larmer, J. W.; Levinsohn, M.; Mc Craw, D.; Pessagno, E. H.; Taub, F. J.

    1964-01-01

    A standard overarm tracing lathe converted by the addition of an independently driven diamond grinding wheel is used for grinding aspheric surfaces. The motion of the wheel is controlled by the lathe air tracer following the template which produces the desired aspheric profile.

  7. Manufacturing processes 2 grinding, honing, lapping

    CERN Document Server

    Klocke, Fritz

    2009-01-01

    Presents a view of the most common machining and non-machining manufacturing processes. This volume describes the characteristics of abrasive tools, their design and manufacturing, followed by the fundamentals of grinding fluids. It also discusses grinding of different materials (steel, cast iron, hard and brittle materials, nickel and titanium).

  8. Deep sequencing analysis of HBV genotype shift and correlation with antiviral efficiency during adefovir dipivoxil therapy.

    Directory of Open Access Journals (Sweden)

    Yuwei Wang

    Full Text Available Viral genotype shift in chronic hepatitis B (CHB patients during antiviral therapy has been reported, but the underlying mechanism remains elusive.38 CHB patients treated with ADV for one year were selected for studying genotype shift by both deep sequencing and Sanger sequencing method.Sanger sequencing method found that 7.9% patients showed mixed genotype before ADV therapy. In contrast, all 38 patients showed mixed genotype before ADV treatment by deep sequencing. 95.5% mixed genotype rate was also obtained from additional 200 treatment-naïve CHB patients. Of the 13 patients with genotype shift, the fraction of the minor genotype in 5 patients (38% increased gradually during the course of ADV treatment. Furthermore, responses to ADV and HBeAg seroconversion were associated with the high rate of genotype shift, suggesting drug and immune pressure may be key factors to induce genotype shift. Interestingly, patients with genotype C had a significantly higher rate of genotype shift than genotype B. In genotype shift group, ADV treatment induced a marked enhancement of genotype B ratio accompanied by a reduction of genotype C ratio, suggesting genotype C may be more sensitive to ADV than genotype B. Moreover, patients with dominant genotype C may have a better therapeutic effect. Finally, genotype shifts was correlated with clinical improvement in terms of ALT.Our findings provided a rational explanation for genotype shift among ADV-treated CHB patients. The genotype and genotype shift might be associated with antiviral efficiency.

  9. DLTAP: A Network-efficient Scheduling Method for Distributed Deep Learning Workload in Containerized Cluster Environment

    Directory of Open Access Journals (Sweden)

    Qiao Wei

    2017-01-01

    Full Text Available Deep neural networks (DNNs have recently yielded strong results on a range of applications. Training these DNNs using a cluster of commodity machines is a promising approach since training is time consuming and compute-intensive. Furthermore, putting DNN tasks into containers of clusters would enable broader and easier deployment of DNN-based algorithms. Toward this end, this paper addresses the problem of scheduling DNN tasks in the containerized cluster environment. Efficiently scheduling data-parallel computation jobs like DNN over containerized clusters is critical for job performance, system throughput, and resource utilization. It becomes even more challenging with the complex workloads. We propose a scheduling method called Deep Learning Task Allocation Priority (DLTAP which performs scheduling decisions in a distributed manner, and each of scheduling decisions takes aggregation degree of parameter sever task and worker task into account, in particularly, to reduce cross-node network transmission traffic and, correspondingly, decrease the DNN training time. We evaluate the DLTAP scheduling method using a state-of-the-art distributed DNN training framework on 3 benchmarks. The results show that the proposed method can averagely reduce 12% cross-node network traffic, and decrease the DNN training time even with the cluster of low-end servers.

  10. Precision diamond grinding of ceramics and glass

    Energy Technology Data Exchange (ETDEWEB)

    Smith, S.; Paul, H.; Scattergood, R.O.

    1988-12-01

    A new research initiative will be undertaken to investigate the effect of machine parameters and material properties on precision diamond grinding of ceramics and glass. The critical grinding depth to initiate the plastic flow-to-brittle fracture regime will be directly measured using plunge-grind tests. This information will be correlated with machine parameters such as wheel bonding and diamond grain size. Multiaxis grinding tests will then be made to provide data more closely coupled with production technology. One important aspect of the material property studies involves measuring fracture toughness at the very short crack sizes commensurate with grinding damage. Short crack toughness value`s can be much less than the long-crack toughness values measured in conventional fracture tests.

  11. Electrolytic in process dressing (ELID) applied to double side grinding of ceramic materials

    Science.gov (United States)

    Spanu, Cristian E.

    The objective of the present work is to design, optimize, and validate an electrolytic in-process dressing (ELID)-assisted double side grinding process for finishing advanced ceramic components. To attain this objective, an original ELID double side grinding system was designed, fabricated, and operated at Precision Micro-Machining Center at The University of Toledo, Ohio. The ELID technique was selected from among other options to assure the in-situ dressing of the metal-bonded superabrasive grinding wheel and to maintain its cutting ability throughout the operation, which is, otherwise, a challenging enterprise. Optimizing the ELID double side grinding process parameters is an important goal of the present study. To achieve this goal, a complex integrated model was developed and validated through extensive experimental testing. Four analytical computerized models were developed and integrated: (1) an improved kinematic model of double side grinding accounting for workpiece rotation, which is used to simulate the grinding trajectories; (2) a microscopic model of the interaction between a single diamond grit and the work surface, which is used to predict the volume of material removed; (3) a stochastic model for the topographical characterization of the superabrasive wheel, which leads to a new prediction method of depth of indentation; and (4) an electrolytic oxidation model, which explains the dynamics of the oxide layer. In order to validate the models and to confirm the optimized process, experimental tests were conducted under different conditions: with vitrified and metallic bond grinding wheels, with various average grain sizes of diamond grits, with different superabrasive concentrations, with different grinding fluids, with and without ELID assistance. Our findings show that an optimized ceramic double side grinding process using fine diamond grit is more efficient than lapping in producing very fine surfaces. The experiments confirmed the superiority of

  12. Design and in vivo evaluation of more efficient and selective deep brain stimulation electrodes

    Science.gov (United States)

    Howell, Bryan; Huynh, Brian; Grill, Warren M.

    2015-08-01

    Objective. Deep brain stimulation (DBS) is an effective treatment for movement disorders and a promising therapy for treating epilepsy and psychiatric disorders. Despite its clinical success, the efficiency and selectivity of DBS can be improved. Our objective was to design electrode geometries that increased the efficiency and selectivity of DBS. Approach. We coupled computational models of electrodes in brain tissue with cable models of axons of passage (AOPs), terminating axons (TAs), and local neurons (LNs); we used engineering optimization to design electrodes for stimulating these neural elements; and the model predictions were tested in vivo. Main results. Compared with the standard electrode used in the Medtronic Model 3387 and 3389 arrays, model-optimized electrodes consumed 45-84% less power. Similar gains in selectivity were evident with the optimized electrodes: 50% of parallel AOPs could be activated while reducing activation of perpendicular AOPs from 44 to 48% with the standard electrode to 0-14% with bipolar designs; 50% of perpendicular AOPs could be activated while reducing activation of parallel AOPs from 53 to 55% with the standard electrode to 1-5% with an array of cathodes; and, 50% of TAs could be activated while reducing activation of AOPs from 43 to 100% with the standard electrode to 2-15% with a distal anode. In vivo, both the geometry and polarity of the electrode had a profound impact on the efficiency and selectivity of stimulation. Significance. Model-based design is a powerful tool that can be used to improve the efficiency and selectivity of DBS electrodes.

  13. The study of grinding patterns and factors influencing the grinding areas during sleep bruxism.

    Science.gov (United States)

    Tao, Jianxiang; Liu, Weicai; Wu, Junhua; Zhang, Xuying; Zhang, Yongting

    2015-10-01

    The purpose of this study is to investigate the grinding patterns and discuss the factors influencing the position relationship between intercuspal position (ICP) and grinding area during sleep bruxism. Lateral condylar inclination, inclination of lateral incisal path and freedom in long centric of thirty subjects were measured. The grinding patterns during sleep bruxism were recorded with a bruxism recording device, BruxChecker. The position relationship between ICP and the grinding area was examined. Spearman's rank correlation coefficient was used for correlation analysis between grinding area and free factors (grinding patterns, freedom in long centric and discrepancy between lateral condylar inclination and inclination of lateral incisal path). All 12 subjects with 0mm-freedom in long centric exhibited that ICP of both sides located within the grinding areas. 4 subjects showed that ICP of both sides located outside the grinding areas. There is a significant correlation between 0mm-freedom in long centric and ICP within the grinding areas (p grinding area. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Tapering-induced enhancement of light extraction efficiency of nanowire deep ultraviolet LED by theoretical simulations

    KAUST Repository

    Lin, Ronghui; Galan, Sergio Valdes; Sun, Haiding; Hu, Yangrui; Alias, Mohd Sharizal; Janjua, Bilal; Ng, Tien Khee; Ooi, Boon S.; Li, Xiaohang

    2018-01-01

    A nanowire (NW) structure provides an alternative scheme for deep ultraviolet light emitting diodes (DUV-LEDs) that promises high material quality and better light extraction efficiency (LEE). In this report, we investigate the influence of the tapering angle of closely packed AlGaN NWs, which is found to exist naturally in molecular beam epitaxy (MBE) grown NW structures, on the LEE of NW DUV-LEDs. It is observed that, by having a small tapering angle, the vertical extraction is greatly enhanced for both transverse magnetic (TM) and transverse electric (TE) polarizations. Most notably, the vertical extraction of TM emission increased from 4.8% to 24.3%, which makes the LEE reasonably large to achieve high-performance DUV-LEDs. This is because the breaking of symmetry in the vertical direction changes the propagation of the light significantly to allow more coupling into radiation modes. Finally, we introduce errors to the NW positions to show the advantages of the tapered NW structures can be projected to random closely packed NW arrays. The results obtained in this paper can provide guidelines for designing efficient NW DUV-LEDs.

  15. Towards a Switched-Capacitor Based Stimulator for Efficient Deep-Brain Stimulation

    Science.gov (United States)

    Vidal, Jose; Ghovanloo, Maysam

    2013-01-01

    We have developed a novel 4-channel prototype stimulation circuit for implantable neurological stimulators (INS). This Switched-Capacitor based Stimulator (SCS) aims to utilize charge storage and charge injection techniques to take advantage of both the efficiency of conventional voltage-controlled stimulators (VCS) and the safety and controllability of current-controlled stimulators (CCS). The discrete SCS prototype offers fine control over stimulation parameters such as voltage, current, pulse width, frequency, and active electrode channel via a LabVIEW graphical user interface (GUI) when connected to a PC through USB. Furthermore, the prototype utilizes a floating current sensor to provide charge-balanced biphasic stimulation and ensure safety. The stimulator was analyzed using an electrode-electrolyte interface (EEI) model as well as with a pair of pacing electrodes in saline. The primary motivation of this research is to test the feasibility and functionality of a safe, effective, and power-efficient switched-capacitor based stimulator for use in Deep Brain Stimulation. PMID:21095987

  16. Tapering-induced enhancement of light extraction efficiency of nanowire deep ultraviolet LED by theoretical simulations

    KAUST Repository

    Lin, Ronghui

    2018-04-21

    A nanowire (NW) structure provides an alternative scheme for deep ultraviolet light emitting diodes (DUV-LEDs) that promises high material quality and better light extraction efficiency (LEE). In this report, we investigate the influence of the tapering angle of closely packed AlGaN NWs, which is found to exist naturally in molecular beam epitaxy (MBE) grown NW structures, on the LEE of NW DUV-LEDs. It is observed that, by having a small tapering angle, the vertical extraction is greatly enhanced for both transverse magnetic (TM) and transverse electric (TE) polarizations. Most notably, the vertical extraction of TM emission increased from 4.8% to 24.3%, which makes the LEE reasonably large to achieve high-performance DUV-LEDs. This is because the breaking of symmetry in the vertical direction changes the propagation of the light significantly to allow more coupling into radiation modes. Finally, we introduce errors to the NW positions to show the advantages of the tapered NW structures can be projected to random closely packed NW arrays. The results obtained in this paper can provide guidelines for designing efficient NW DUV-LEDs.

  17. Progress in abrasive and grinding technology

    CERN Document Server

    Xu, Xipeng

    2009-01-01

    The grinding and abrasive processing of materials are machining techniques which use bonded or loose abrasives to remove material from workpieces. Due to the well-known advantages of grinding and abrasive processes, advances in abrasive and grinding technology are always of great import in enhancing both productivity and component quality. In order to highlight the recent progress made in this field, the editor invited 21 world-wide contributions with the aim of gathering together all of the achievements of leading researchers into a single publication. The authors of the 21 invited papers, of

  18. Zirconia changes after grinding and regeneration firing.

    Science.gov (United States)

    Hatanaka, Gabriel R; Polli, Gabriela S; Fais, Laiza M G; Reis, José Maurício Dos S N; Pinelli, Lígia A P

    2017-07-01

    Despite improvements in computer-aided design and computer-aided manufacturing (CAD-CAM) systems, grinding during either laboratory procedures or clinical adjustments is often needed to modify the shape of 3 mol(%) yttria-tetragonal zirconia polycrystal (3Y-TZP) restorations. However, the best way to achieve adjustment is unclear. The purpose of this in vitro study was to evaluate the microstructural and crystallographic phase changes, flexural strength, and Weibull modulus of a 3Y-TZP zirconia after grinding with or without water cooling and regeneration firing. Ninety-six bar-shaped specimens were obtained and divided as follows: as-sintered, control; as-sintered with regeneration firing; grinding without water cooling; grinding and regeneration firing with water cooling; and grinding and regeneration firing. Grinding (0.3 mm) was performed with a 150-μm diamond rotary instrument in a high-speed handpiece. For regeneration firing, the specimens were annealed at 1000°C for 30 minutes. The crystalline phases were evaluated by using x-ray powder diffraction. A 4-point bending test was conducted (10 kN; 0.5 mm/min). The Weibull modulus was used to analyze strength reliability. The microstructure was analyzed by scanning electron microscopy. Data from the flexural strength test were evaluated using the Kruskal-Wallis and Dunn tests (α=.05). Tetragonal-to-monoclinic phase transformation was identified in the ground specimens; R regeneration firing groups showed only the tetragonal phase. The median flexural strength of as-sintered specimens was 642.0; 699.3 MPa for as-sintered specimens with regeneration firing; 770.1 MPa for grinding and water-cooled specimens; 727.3 MPa for specimens produced using water-cooled grinding and regeneration firing; 859.9 MPa for those produced by grinding; and 764.6 for those produced by grinding and regeneration firing; with statistically higher values for the ground groups. The regenerative firing did not affect the flexural

  19. Metastable structure formation during high velocity grinding

    International Nuclear Information System (INIS)

    Samarin, A.N.; Klyuev, M.M.

    1984-01-01

    Metastable structures in surface layers of samples are; investigated during force high-velocity abrasive grinding. Samples of martensitic (40Kh13), austenitic (12Kh18N10T), ferritic (05Kh23Yu5) steels and some alloys, in particular KhN77TYuR (EhI437B), were grinded for one pass at treatment depth from 0.17 up to 2.6 mm. It is established that processes of homogenizing, recrystallization and coagulation are; developed during force high-velocity grinding along with polymorphic transformations in the zone of thermomechanical effect, that leads to changes of physical and mechanical properties of the surface

  20. Automatic grinding apparatus to control uniform specimen thicknesses

    Science.gov (United States)

    Bryner, Joseph S.

    1982-01-01

    This invention is directed to a new and improved grinding apparatus comprising (1) a movable grinding surface, (2) a specimen holder, (3) a displacing device for moving the holder and/or grinding surface toward one another, and (4) at least three devices for limiting displacement of the holder to the grinding surface.

  1. 30 CFR 75.1723 - Stationary grinding machines; protective devices.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Stationary grinding machines; protective....1723 Stationary grinding machines; protective devices. (a) Stationary grinding machines other than... the wheel. (3) Safety washers. (b) Grinding wheels shall be operated within the specifications of the...

  2. Mathematical simulation of bearing ring grinding process

    Science.gov (United States)

    Koltunov, I. I.; Gorbunova, T. N.; Tumanova, M. B.

    2018-03-01

    The paper suggests the method of forming a solid finite element model of the bearing ring. Implementation of the model allowed one to evaluate the influence of the inner cylindrical surface grinding scheme on the ring shape error.

  3. Accounting for Organic Carbon Change in Deep Soil Altered Carbon Sequestration Efficiency

    Science.gov (United States)

    Li, J.; Liang, F.; Xu, M.; Huang, S.

    2017-12-01

    Study on soil organic carbon (SOC) sequestration under fertilization practices in croplands lacks information of soil C change at depth lower than plow layer (i.e. 20 30-cm). By synthesizing long-term datasets of fertilization experiments in four typical Chinese croplands representing black soil at Gongzhuling(GZL), aquatic Chao soil at Zhengzhou(ZZ), red soil at Qiyang(QY) and purple soil at Chongqing(CQ) city, we calculated changes in SOC storage relative to initial condition (ΔSOC) in 0-20cm and 0-60cm, organic C inputs (OC) from the stubble, roots and manure amendment, and C sequestration efficiency (CSE: the ratio of ΔSOC over OC) in 0-20cm and 0-60cm. The fertilization treatments include cropping with no fertilization (CK), chemical nitrogen, phosphorus and potassium fertilizers (NPK) and combined chemical fertilizers and manure (NPKM). Results showed SOC storage generally decreased with soil depth (i.e. 0-20 > 20-40, 40-60 cm) and increased with fertilizations (i.e. initial fertilizations, soil at depth (>20cm) can act as important soil carbon sinks in intrinsically high fertility soils (i.e. black soil) but less likely at poor fertility soil (i.e. aquatic Chao soil). It thus informs the need to account for C change in deep soils for estimating soil C sequestration capacity particularly with indigenously fertile cropland soils.

  4. Matrix model of the grinding process of cement clinker in the ball mill

    Science.gov (United States)

    Sharapov, Rashid R.

    2018-02-01

    In the article attention is paid to improving the efficiency of production of fine powders, in particular Portland cement clinker. The questions of Portland cement clinker grinding in closed circuit ball mills. Noted that the main task of modeling the grinding process is predicting the granulometric composition of the finished product taking into account constructive and technological parameters used ball mill and separator. It is shown that the most complete and informative characterization of the grinding process in a ball mill is a grinding matrix taking into account the transformation of grain composition inside the mill drum. Shows how the relative mass fraction of the particles of crushed material, get to corresponding fraction. Noted, that the actual task of reconstruction of the matrix of grinding on the experimental data obtained in the real operating installations. On the basis of experimental data obtained on industrial installations, using matrix method to determine the kinetics of the grinding process in closed circuit ball mills. The calculation method of the conversion of the grain composition of the crushed material along the mill drum developed. Taking into account the proposed approach can be optimized processing methods to improve the manufacturing process of Portland cement clinker.

  5. Grinding performance evaluation of porous composite-bonded CBN wheels for Inconel 718

    Directory of Open Access Journals (Sweden)

    Chen Zhenzhen

    2014-08-01

    Full Text Available For high-efficiency grinding of difficult-to-cut materials such as titanium and nickel alloys, a high porosity is expected and also a sufficient mechanical strength to satisfy the function. However, the porosity increase is a disadvantage to the mechanical strength. As a promising pore forming agent, alumina bubbles are firstly induced into the abrasive layer to fabricate porous cubic boron nitride (CBN wheels. When the wheel porosity reaches 45%, the bending strength is still high up to 50 MPa with modified orderly pore distribution. A porous CBN wheel was fabricated with a total porosity around 30%. The grinding performance of the porous composite-bonded CBN wheel was evaluated in terms of specific force, specific grinding energy, and grinding temperature, which were better than those of the vitrified one under the same grinding conditions. Compared to the vitrified CBN wheel, clear straight cutting grooves and less chip adhesion are observed on the ground surface and there is also no extensive loading on the wheel surface after grinding.

  6. Techniques for chamfer and taper grinding of oxide fuel pellets (LWBR Development Program)

    International Nuclear Information System (INIS)

    Johnson, R.G.R.; Allison, J.W.

    1981-10-01

    Floor mounted centerless grinding machines were adapted for shaping the edges of cylindrical oxide fuel pellets for the Light Water Breeder Reactor (LWBR) by plunge grinding. Edge configurations consisted of chamfers, either 0.015 inch x 45 0 or 0.006 inch x 45 0 , or tapers 0.150 inch long x .0025 inch deep. Grinding was done by plunging the pellet against a shaped grinding wheel which ground both the diameter to the required size and shaped the edges of the pellet. Two plunges per pellet were required to complete the operation. Separate wheels were needed for grinding either a chamfer or a taper, the set up was adjustable to vary the size of the chamfer or taper as needed. The set up also had the flexibility to accommodate the multiple pellet lengths and diameters required by the LWBR design. Tight manufacturing tolerances in the chamfer and taper dimensions required the use of dimensional control charts and statistical sampling plans as process controls

  7. A Review of Literature on analysis of JIG Grinding Process

    DEFF Research Database (Denmark)

    Sudheesh, P. K.; Puthumana, Govindan

    2016-01-01

    Jig grinding is a process practically used by tool and die makers in the creation of jigs or mating holes and pegs on dies.The abrasives normally used in jig grinding are divided into Natural Abrasives and Artificial Abrasives. Artificial Abrasiveare preferred in manufacturing of grinding wheels...... in jig grinding, because of their uniformity and purity. In this paper, abrief review of the analysis of jig grinding process considering various research trends is presented. The areas highlighted are: optimization, selection of abrasives, selection of processing conditions and practical considerations....... The optimization of parameters in jig grinding process is important to maximize productivity and to improve quality. The abrasives of hard jig grinding wheels get blunt quickly so these are recommended to grind workpiece of low hardness and soft grinding wheels are recommended for hard material workpieces. The jig...

  8. Influence of Cooling Condition on the Performance of Grinding Hardened Layer in Grind-hardening

    Science.gov (United States)

    Wang, G. C.; Chen, J.; Xu, G. Y.; Li, X.

    2018-02-01

    45# steel was grinded and hardened on a surface grinding machine to study the effect of three different cooling media, including emulsion, dry air and liquid nitrogen, on the microstructure and properties of the hardened layer. The results show that the microstructure of material surface hardened with emulsion is pearlite and no hardened layer. The surface roughness is small and the residual stress is compressive stress. With cooling condition of liquid nitrogen and dry air, the specimen surface are hardened, the organization is martensite, the surface roughness is also not changed, but high hardness of hardened layer and surface compressive stress were obtained when grinding using liquid nitrogen. The deeper hardened layer grinded with dry air was obtained and surface residual stress is tensile stress. This study provides an experimental basis for choosing the appropriate cooling mode to effectively control the performance of grinding hardened layer.

  9. Subtask 2.17 - CO2 Storage Efficiency in Deep Saline Formations

    Energy Technology Data Exchange (ETDEWEB)

    Gorecki, Charles D. [Univ. of North Dakota, Grand Forks, ND (United States); Liu, Guoxiang [Univ. of North Dakota, Grand Forks, ND (United States); Braunberger, Jason R. [Univ. of North Dakota, Grand Forks, ND (United States); Klenner, Robert C. L. [Univ. of North Dakota, Grand Forks, ND (United States); Ayash, Scott C. [Univ. of North Dakota, Grand Forks, ND (United States); Dotzenrod, Neil W. [Univ. of North Dakota, Grand Forks, ND (United States); Steadman, Edward N. [Univ. of North Dakota, Grand Forks, ND (United States); Harju, John A. [Univ. of North Dakota, Grand Forks, ND (United States)

    2014-02-01

    As the field of carbon capture and storage (CCS) continues to advance, and large-scale implementation of geologic carbon dioxide (CO2) storage progresses, it will be important to understand the potential of geologic formations to store meaningful amounts of CO2. Geologic CO2 storage in deep saline formations (DSFs) has been suggested as one of the best potential methods for reducing anthropogenic CO2 emission to the atmosphere, and as such, updated storage resource estimation methods will continue to be an important component for the widespread deployment of CCS around the world. While there have been several methodologies suggested in the literature, most of these methods are based on a volumetric calculation of the pore volume of the DSF multiplied by a storage efficiency term and do not consider the effect of site-specific dynamic factors such as injection rate, injection pattern, timing of injection, pressure interference between injection locations, and overall formation pressure buildup. These volumetric methods may be excellent for comparing the potential between particular formations or basins, but they have not been validated through real-world experience or full-formation injection simulations. Several studies have also suggested that the dynamic components of geologic storage may play the most important role in storing CO2 in DSFs but until now have not directly compared CO2 storage resource estimates made with volumetric methodologies to estimates made using dynamic CO2 storage methodologies. In this study, two DSFs, in geographically separate areas with geologically diverse properties, were evaluated with both volumetric and dynamic CO2 storage resource estimation methodologies to compare the results and determine the applicability of both approaches. In the end, it was determined that the dynamic CO2 storage resource potential is timedependent and it

  10. Key Technology Research on the Efficient Exploitation and Comprehensive Utilization of Resources in the Deep Jinchuan Nickel Deposit

    Directory of Open Access Journals (Sweden)

    Zhiqiang Yang

    2017-08-01

    Full Text Available To understand the resource features and geology in the deep Jinchuan nickel deposit, difficult geological conditions were systematically analyzed, including high stress, fragmentized ore rock, prevalent deformation, difficult tunnel support, complicated rock mechanics, and low mining recovery. An integrated technology package was built for safe, efficient, and continuous mining in a deep, massive, and complex nickel and cobalt mine. This was done by the invention of a large-area continuous mining method with honeycomb drives; the establishment of ground control theory and a technology package for high-stress and fragmented ore rock; and the development of a new type of backfilling cement material, along with a deep backfilling technology that comprises the pipeline transport of high-density slurry with coarse aggregates. In this way, good solutions to existing problems were found to permit the efficient exploitation and comprehensive utilization of the resources in the deep Jinchuan nickel mine. In addition, a technological demonstration in an underground mine was performed using the cemented undercut-and-fill mining method for stressful, fragmented, and rheological rock.

  11. Workpiece Temperature Variations During Flat Peripheral Grinding

    Science.gov (United States)

    Smirnov, Vitalii A.; Repko, Aleksandr V.

    2018-06-01

    The paper presents the results of researches of temperature variations during flat peripheral grinding. It is shown that the temperature variations of the workpiece can reach 25...30% of the average values, which can lead to some thermal defects. A nonlinear two-dimensional thermophysical grinding model is suggested. It takes into account local changes in the cutting conditions: the fluctuation of the cut layer and the cutting force, the thermal impact of the cutting grains, and the presence of surface cavities in the intermittent wheel. For the numerical solution of the problem, the method of finite differences is adapted. Researches of the method stability and convergence are made, taking into account the specific nature of the problem. A high accuracy of the approximation of the boundary conditions and the nonlinear heat equation is provided. An experimental verification of the proposed thermophysical model was carried out with the use of installation for simultaneous measurement of the grinding force and temperature. It is shown that the discrepancy between the theoretical and experimental values of the grinding temperature does not exceed 5%. The proposed thermophysical model makes it possible to predict with high accuracy the temperature variations during grinding by the wheel periphery.

  12. A Review of Literature on analysis of JIG Grinding Process

    DEFF Research Database (Denmark)

    Sudheesh, P. K.; Puthumana, Govindan

    2016-01-01

    in jig grinding, because of their uniformity and purity. In this paper, abrief review of the analysis of jig grinding process considering various research trends is presented. The areas highlighted are: optimization, selection of abrasives, selection of processing conditions and practical considerations....... The optimization of parameters in jig grinding process is important to maximize productivity and to improve quality. The abrasives of hard jig grinding wheels get blunt quickly so these are recommended to grind workpiece of low hardness and soft grinding wheels are recommended for hard material workpieces. The jig...

  13. High-Efficiency, High-Power Laser Transmitter for Deep-Space Communication, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — There is demand for vastly improved deep space satellite communications links. As data rates dramatically increase due to new sensor technologies and the desire to...

  14. A novel method of freeform surface grinding with a soft wheel based on industrial robots

    Science.gov (United States)

    Sha, Sheng-chun; Guo, Xiao-ling

    2011-08-01

    In order to meet the growing demand for high-quality images, optical elements of freeform surface are more and more applied to imaging system. However the fabrication of freeform surface optical elements is much more difficult than that of traditional spherical ones. Recent research on freeform surface manufacture often deals with precision machine tools which have limitations on dimensions and are always expensive. Little has been researched on industrial robots. In this paper, a new method of freeform surface grinding based on industrial robots was found. This method could be applied to both whole surface grinding as well as partial surface grinding. The diameter of lenses to be ground would not be restricted to the machine tool's size. In this method a high-speed-rotating soft wheel was used. The relation between removing amount and grinding time which could be called removing function was established and measured. The machining precision was achieved by means of controlling the grinding time instead of the machine tool or industrial robot itself. There are two main factors affecting the removing function: i).rotating speed of the soft wheel; ii).pressure between the wheel and the work piece. In this paper, two groups of experiments have been conducted. One is the removing function tested at constant rotating speed while under different pressure. The other is that tested under a certain pressure with variable speed. Tables and curves which can show the effect of speed and pressure on the removing efficiency have been obtained. Cause for inaccuracy between experiment data and calculated result according to the theory and the non-linearity in the curves was analyzed. Through these analyses the removing function could be concluded under certain condition including rotating speed and pressure. Finally several experiments were performed to verify the appropriateness of the removing function. It could also be concluded that this method was more efficient in comparison

  15. Efficiency analyses of the CANDU spent fuel repository using modified disposal canisters for a deep geological disposal system design

    International Nuclear Information System (INIS)

    Lee, J.Y.; Cho, D.K.; Lee, M.S.; Kook, D.H.; Choi, H.J.; Choi, J.W.; Wang, L.M.

    2012-01-01

    Highlights: ► A reference disposal concept for spent nuclear fuels in Korea has been reviewed. ► To enhance the disposal efficiency, alternative disposal concepts were developed. ► Thermal analyses for alternative disposal concepts were performed. ► From the result of the analyses, the disposal efficiency of the concepts was reviewed. ► The most effective concept was suggested. - Abstract: Deep geological disposal concept is considered to be the most preferable for isolating high-level radioactive waste (HLW), including nuclear spent fuels, from the biosphere in a safe manner. The purpose of deep geological disposal of HLW is to isolate radioactive waste and to inhibit its release of for a long time, so that its toxicity does not affect the human beings and the biosphere. One of the most important requirements of HLW repository design for a deep geological disposal system is to keep the buffer temperature below 100 °C in order to maintain the integrity of the engineered barrier system. In this study, a reference disposal concept for spent nuclear fuels in Korea has been reviewed, and based on this concept, efficient alternative concepts that consider modified CANDU spent fuels disposal canister, were developed. To meet the thermal requirement of the disposal system, the spacing of the disposal tunnels and that of the disposal pits for each alternative concept, were drawn following heat transfer analyses. From the result of the thermal analyses, the disposal efficiency of the alternative concepts was reviewed and the most effective concept suggested. The results of these analyses can be used for a deep geological repository design and detailed analyses, based on exact site characteristics data, will reduce the uncertainty of the results.

  16. Microwave-assisted grinding of metallurgical coke

    International Nuclear Information System (INIS)

    Ruisanchez, E.; Juarez-Perez, E. J.; Arenillas, A.; Bermudez, J. M.; Menendez, J. A.

    2014-01-01

    Metallurgical cokes are composed of graphitic carbon (s2p2) and different inorganic compounds with very different capacities to absorb microwave radiation. Moreover, due to the electric conductivity shown by the metallurgical cokes, microwave radiation produces electric arcs or microplasmas, which gives rise to hot spots. Therefore, when these cokes are irradiated with microwaves some parts of the particle experiment a rapid heating, while some others do not heat at all. As a result of the different expansion and stress caused by thermal the shock, small cracks and micro-fissures are produced in the particle. The weakening of the coke particles, and therefore an improvement of its grind ability, is produced. This paper studies the microwave-assisted grinding of metallurgical coke and evaluates the grinding improvement and energy saving. (Author)

  17. Grinding Fluid Jet Characteristics and Their Effect on a Gear Profile Grinding Process

    Directory of Open Access Journals (Sweden)

    Philip Geilert

    2017-10-01

    Full Text Available Profile gear grinding is characterized by a high level of achievable process performance and workpiece quality. However, the wide contact length between the workpiece and the grinding wheel is disadvantageous for the fluid supply to the contact zone and leads to the risk of locally burning the workpiece surface. For the reduction of both the thermal load and the risk of thermo-mechanical damage, the usage of a grinding fluid needs to be investigated and optimized. For this purpose, different kinds of grinding fluid nozzles were tested, which provide different grinding fluid jet characteristics. Through a specific design of the nozzles, it is possible to control the fluid flow inside the nozzle. It was found that this internal fluid flow directly influences the breakup of the coolant fluid jet. There are three groups of jet breakup (“droplet”, “wave & droplet”, and “atomization”. The first experimental results show that the influence of the jet breakup on the process performance is significant. The “wave & droplet” jet breakup can achieve a high process performance, in contrast to the “atomization” jet breakup. It can therefore be assumed that the wetting of the grinding wheel by the grinding fluid jet is significantly influenced by the jet breakup.

  18. Twyman effect mechanics in grinding and microgrinding.

    Science.gov (United States)

    Lambropoulos, J C; Xu, S; Fang, T; Golini, D

    1996-10-01

    In the Twyman effect (1905), when one side of a thin plate with both sides polished is ground, the plate bends: The ground side becomes convex and is in a state of compressive residual stress, described in terms of force per unit length (Newtons per meter) induced by grinding, the stress (Newtons per square meter) induced by grinding, and the depth of the compressive layer (micrometers). We describe and correlate experiments on optical glasses from the literature in conditions of loose abrasive grinding (lapping at fixed nominal pressure, with abrasives 4-400 μm in size) and deterministic microgrinding experiments (at a fixed infeed rate) conducted at the Center for Optics Manufacturing with bound diamond abrasive tools (with a diamond size of 3-40 μm, embedded in metallic bond) and loose abrasive microgrinding (abrasives of less than 3 μm in size). In brittle grinding conditions, the grinding force and the depth of the compressive layer correlate well with glass mechanical properties describing the fracture process, such as indentation crack size. The maximum surface residual compressive stress decreases, and the depth of the compressive layer increases with increasing abrasive size. In lapping conditions the depth of the abrasive grain penetration into the glass surface scales with the surface roughness, and both are determined primarily by glass hardness and secondarily by Young's modulus for various abrasive sizes and coolants. In the limit of small abrasive size (ductile-mode grinding), the maximum surface compressive stress achieved is near the yield stress of the glass, in agreement with finite-element simulations of indentation in elastic-plastic solids.

  19. Area- and energy-efficient CORDIC accelerators in deep sub-micron CMOS technologies

    Science.gov (United States)

    Vishnoi, U.; Noll, T. G.

    2012-09-01

    The COordinate Rotate DIgital Computer (CORDIC) algorithm is a well known versatile approach and is widely applied in today's SoCs for especially but not restricted to digital communications. Dedicated CORDIC blocks can be implemented in deep sub-micron CMOS technologies at very low area and energy costs and are attractive to be used as hardware accelerators for Application Specific Instruction Processors (ASIPs). Thereby, overcoming the well known energy vs. flexibility conflict. Optimizing Global Navigation Satellite System (GNSS) receivers to reduce the hardware complexity is an important research topic at present. In such receivers CORDIC accelerators can be used for digital baseband processing (fixed-point) and in Position-Velocity-Time estimation (floating-point). A micro architecture well suited to such applications is presented. This architecture is parameterized according to the wordlengths as well as the number of iterations and can be easily extended for floating point data format. Moreover, area can be traded for throughput by partially or even fully unrolling the iterations, whereby the degree of pipelining is organized with one CORDIC iteration per cycle. From the architectural description, the macro layout can be generated fully automatically using an in-house datapath generator tool. Since the adders and shifters play an important role in optimizing the CORDIC block, they must be carefully optimized for high area and energy efficiency in the underlying technology. So, for this purpose carry-select adders and logarithmic shifters have been chosen. Device dimensioning was automatically optimized with respect to dynamic and static power, area and performance using the in-house tool. The fully sequential CORDIC block for fixed-point digital baseband processing features a wordlength of 16 bits, requires 5232 transistors, which is implemented in a 40-nm CMOS technology and occupies a silicon area of 1560 μm2 only. Maximum clock frequency from circuit

  20. 15N tracer technique for studying efficiency of deep placed fertilizer through nutriseed holder in direct seeded rice

    International Nuclear Information System (INIS)

    Asha, V.S.; Arulmozhiselvan, K.

    2006-01-01

    In order to estimate N use efficiency in deep placement of NPK straight fertilizers, two pot experiments were conducted in high clay soil with direct seeded rice. 15 N urea was used as a tracer. A newly designed 'Nutriseed Holder' was used for simultaneous deep placement of fertilizers and sowing of seeds. Each holder had two cavities, one on top for holding seed and another one at bottom for holding fertilizer material. By implanting a holder in puddled soil, a rice hill was established. The length (5 or 10 cm) and width (8 or 12 mm) of nutriseed holder was standardized while evaluating the effect of Azolla, neem and seed inoculants. Appreciably, deep placement of plain NPK fertilizer in 12 mm holder placed at 5 cm depth recorded the highest grain yield with a yield increase of 81.8 per cent during rabi 2002 (cv CO 43) and 84.8 per cent during summer 2003 (cv CO 47) over broadcast application. Further, it increased recovery of added JSN in grain + straw to the tune of 57.1 per cent in rabi and 54.7 per cent in summer as compared to broadcast application (26.1% in rabi, 34.2 in summer). Deep placement enhanced more retention in soil (up to 9.0% in rabi, 14.6% in summer) whereas broadcast application enhanced more retention in Azolla biomass that was grown in floodwater (up to 2.3 % in rabi, 4.3 % in summer). Use of 12 mm width nutriseed holder aiding deep placement at 5 cm depth was found suitable for deriving high yield and N use efficiency. (author)

  1. Energy requirement for fine grinding of torrefied wood

    Energy Technology Data Exchange (ETDEWEB)

    Repellin, Vincent; Govin, Alexandre; Guyonnet, Rene [Department of Powder and Multi-Components Materials (PMMC), SPIN Research Center, Ecole des Mines de Saint Etienne (EMSE), 158 Cours Fauriel, F-42023 Saint-Etienne (France); Rolland, Matthieu [Process Developments and Engineering Division, Chemical Engineering Department, Institut Francais du Petrole (IFP-Lyon), F-69390 Vernaison (France)

    2010-07-15

    The purpose of this study is to investigate the influence of torrefaction on wood grinding energy. Wood chips were torrefied at different temperatures and durations. The energy required to obtain fine powder was measured. Particle size analyses were carried out on each powder sample. It is showed that torrefaction decreases both grinding energy and particle size distribution. A criterion to compare grindability of natural and torrefied wood is proposed. It takes into account both grinding energy and particle size distribution. It accounts the energy required for grinding particles to sizes inferior to 200 {mu}m, for given grinding conditions. Torrefaction is characterised by the anhydrous weight loss (AWL) of wood. For AWL inferior to around 8%, grinding energy decreases fast. Over 8%, grinding energy decreases at a slow rate. Particle size distribution decreases linearly as the AWL increases. Both for spruce and beech, the grinding criterion is decreased of 93% when the AWL is around 28%. (author)

  2. Research on precision grinding technology of large scale and ultra thin optics

    Science.gov (United States)

    Zhou, Lian; Wei, Qiancai; Li, Jie; Chen, Xianhua; Zhang, Qinghua

    2018-03-01

    The flatness and parallelism error of large scale and ultra thin optics have an important influence on the subsequent polishing efficiency and accuracy. In order to realize the high precision grinding of those ductile elements, the low deformation vacuum chuck was designed first, which was used for clamping the optics with high supporting rigidity in the full aperture. Then the optics was planar grinded under vacuum adsorption. After machining, the vacuum system was turned off. The form error of optics was on-machine measured using displacement sensor after elastic restitution. The flatness would be convergenced with high accuracy by compensation machining, whose trajectories were integrated with the measurement result. For purpose of getting high parallelism, the optics was turned over and compensation grinded using the form error of vacuum chuck. Finally, the grinding experiment of large scale and ultra thin fused silica optics with aperture of 430mm×430mm×10mm was performed. The best P-V flatness of optics was below 3 μm, and parallelism was below 3 ″. This machining technique has applied in batch grinding of large scale and ultra thin optics.

  3. MICRO-ARC DIELECTRIC COATINGS ON ALUMINUM ALLOYS OF GRINDING WHEEL FRAMEWORKS

    Directory of Open Access Journals (Sweden)

    Yury GUTSALENKO

    2018-05-01

    Full Text Available It is presented the development of local electrically insulating coatings for tool of the technologies of high-efficient processing with the introduction the energy of electrical discharges into the cutting zone to maintain a working capacity of grinding wheels with diamond-metal composition of the working part. Development is an alternative to the electrical insulation upgrade of spindle units of universal grinding machines. The dielectric properties of micro-arc oxide coatings on deformable aluminum alloys formed on an alternating current in the regime of an arbitrarily falling power in alkali-silicate solutions have been studied. Information about the features of practical implementation of development is given.

  4. Hydrogen effects in anodic grinding of WC-Co sintered alloy

    International Nuclear Information System (INIS)

    Lunarska, E.; Zaborski, St.

    2001-01-01

    The effects of anodic polarization applied in grinding of sintered WC C o alloy on properties of surface layer, quality of ground surface and efficiency of the treatment were studied. The nonmonotonical change of the surface roughness, the energy consumption and the wear of tool was stated at increasing anodic polarization. The optimum values of above parameters were achieved at application of anodic polarization at which the Co selective dissolution and hydrogen ingress into the ground metal. affecting the internal friction spectra were stated. The assistance of hydrogen induced deterioration and Co selective dissolution in the surface layer in the anodic grinding of WC-Co alloy has been discussed. (author)

  5. 30 CFR 57.14115 - Stationary grinding machines.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Stationary grinding machines. 57.14115 Section... and Equipment Safety Devices and Maintenance Requirements § 57.14115 Stationary grinding machines. Stationary grinding machines, other than special bit grinders, shall be equipped with— (a) Peripheral hoods...

  6. 30 CFR 77.401 - Stationary grinding machines; protective devices.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Stationary grinding machines; protective... OF UNDERGROUND COAL MINES Safeguards for Mechanical Equipment § 77.401 Stationary grinding machines; protective devices. (a) Stationary grinding machines other than special bit grinders shall be equipped with...

  7. 30 CFR 56.14115 - Stationary grinding machines.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Stationary grinding machines. 56.14115 Section... Equipment Safety Devices and Maintenance Requirements § 56.14115 Stationary grinding machines. Stationary grinding machines, other than special bit grinders, shall be equipped with— (a) Peripheral hoods capable of...

  8. Deep eutectic solvents for highly efficient separations in oil and gas industries

    NARCIS (Netherlands)

    Warrag, S.E.E.; Peters, C.J.; Kroon, M.C.

    2017-01-01

    Deep eutectic solvents (DESs) have captured a great scientific attention as a new, ‘green’ and sustainable class of tailor-made solvents. DESs share many properties with ionic liquids (ILs) including low vapor pressure, wide liquid range, thermal stability, low flammability, and high solvation

  9. Efficient forward propagation of time-sequences in convolutional neural networks using Deep Shifting

    NARCIS (Netherlands)

    K.L. Groenland (Koen); S.M. Bohte (Sander)

    2016-01-01

    textabstractWhen a Convolutional Neural Network is used for on-the-fly evaluation of continuously updating time-sequences, many redundant convolution operations are performed. We propose the method of Deep Shifting, which remembers previously calculated results of convolution operations in order

  10. Broad Learning System: An Effective and Efficient Incremental Learning System Without the Need for Deep Architecture.

    Science.gov (United States)

    Chen, C L Philip; Liu, Zhulin

    2018-01-01

    Broad Learning System (BLS) that aims to offer an alternative way of learning in deep structure is proposed in this paper. Deep structure and learning suffer from a time-consuming training process because of a large number of connecting parameters in filters and layers. Moreover, it encounters a complete retraining process if the structure is not sufficient to model the system. The BLS is established in the form of a flat network, where the original inputs are transferred and placed as "mapped features" in feature nodes and the structure is expanded in wide sense in the "enhancement nodes." The incremental learning algorithms are developed for fast remodeling in broad expansion without a retraining process if the network deems to be expanded. Two incremental learning algorithms are given for both the increment of the feature nodes (or filters in deep structure) and the increment of the enhancement nodes. The designed model and algorithms are very versatile for selecting a model rapidly. In addition, another incremental learning is developed for a system that has been modeled encounters a new incoming input. Specifically, the system can be remodeled in an incremental way without the entire retraining from the beginning. Satisfactory result for model reduction using singular value decomposition is conducted to simplify the final structure. Compared with existing deep neural networks, experimental results on the Modified National Institute of Standards and Technology database and NYU NORB object recognition dataset benchmark data demonstrate the effectiveness of the proposed BLS.

  11. Grinding of WC–Co hardmetals

    NARCIS (Netherlands)

    Hegeman, J.B.J.W.; Hosson, J.Th.M. De; With, G. de

    2001-01-01

    This paper concentrates on the morphology of the ground surface of cobalt tungsten carbide (WC) composite materials that belong to the category of so-called hardmetals. A deformed and detached surface layer was found on top of the specimens after surface grinding with a diamond wheel. In order to

  12. Grinding Glass Disks On A Belt Sander

    Science.gov (United States)

    Lyons, James J., III

    1995-01-01

    Small machine attached to table-top belt sander makes possible to use belt sander to grind glass disk quickly to specified diameter within tolerance of about plus or minus 0.002 in. Intended to be used in place of production-shop glass grinder. Held on driveshaft by vacuum, glass disk rotated while periphery ground by continuous sanding belt.

  13. Carving up Word Meaning: Portioning and Grinding

    Science.gov (United States)

    Frisson, S.; Frazier, L.

    2005-01-01

    Two eye-tracking experiments investigated the processing of mass nouns used as count nouns and count nouns used as mass nouns. Following Copestake and Briscoe (1995), the basic or underived sense of a word was treated as the input to a derivational rule (''grinding'' or ''portioning'') which produced the derived sense as output. It was…

  14. Performance Evaluation of Abrasive Grinding Wheel Formulated ...

    African Journals Online (AJOL)

    This paper presents a study on the formulation and manufacture of abrasive grinding wheel using locally formulated silicon carbide abrasive grains. Six local raw material substitutes were identified through pilot study and with the initial mix of the identified materials, a systematic search for an optimal formulation of silicon ...

  15. Effects of grinding on certain crystalline structures

    International Nuclear Information System (INIS)

    Tekiz, Y.

    1965-06-01

    The effects of grinding on certain crystalline substances (ZnO, ZnS, Sb), have been studied using X-ray diffraction and electron microscopy. The treatments were carried out using a vibrating mill which involves a higher energy than more conventional equipment such as ball-mills. Various methods have been proposed for determining the width of the intrinsic profile (β). In the case of zinc oxide it has been shown possible to differentiate the respective contributions of the fragmentation effects and of lattice deformation effects to the overall effects of the grinding. For the two types of zinc sulfide (blend and Wurtzite) it has been shown that the blend-wurtzite) transition point is very much decreased, and that the rate of transformation of wurtzite into the stable form (blend) at room temperature is considerably increased by the grinding. In the case of antimony, the method of fragmentation shows the existence of an anisotropy which appears to be connected with easily cleavable planes. These observations show that in the case of grinding carried out with sufficient energy, the accumulation of this energy in the matter through the creation of lattice defects can accelerate the reaction rate or bring about physical transformations. (author) [fr

  16. FY 1998 annual report on the development of laser-aided, noncontacting, realtime, in-process dressing method using a grinding stone with ultrafine abrasive grains, and study on techniques for applying the method to grinding stone of superthin blades; 1998 nendo laser wo mochiita choteiryu toishi no hisesshoku real time inprocess dressing ho no kaihatsu oyobi gokuusuha toishi eno tekiyo gijutsu ni kansuru kenkyu chosa hokokusho

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-03-01

    A new noncontacting dressing method using a laser as a tool has been studied and developed, in order to develop environment-compatible, energy-saving type machining machines. In this study, a cup-shaped grinding stone is developed for grinding performance testing by micron-order diamond abrasive powder, used for producing a grinding stone of superthin blades, is mixed with a cast iron binder, molded and sintered. In the grinding performance test, zirconia as a work is ground at a constant pressure to the grinding stone working surface before and after the laser-aided dressing, to analyze grinding/removal efficiency and grinding resistance. The grinding stone working surface conditions are observed by a scanning electron microscope after the laser-aided dressing, to correlate the surface conditions with the grinding data. It is found that the laser-aided dressing method needs no lubricant, is clean, cutting grinding time when incorporated in the machining process, suitable for grinding stone of low stiffness and ultrathin blades by use of ultrafine abrasive grains, suffering no exfoliation of the diamond grains, and hence economical. (NEDO)

  17. Grinding into Soft, Powdery Rock

    Science.gov (United States)

    2004-01-01

    This hole in a rock dubbed 'Clovis' is the deepest hole drilled so far in any rock on Mars. NASA's Mars Exploration Rover Spirit captured this view with its microscopic imager on martian sol 217 (Aug. 12, 2004) after drilling 8.9 millimeters (0.35 inch) into the rock with its rock abrasion tool. The view is a mosaic of four frames taken by the microscopic imager. The hole is 4.5 centimeters (1.8 inches) in diameter. Clovis is key to a developing story about environmental change on Mars, not only because it is among the softest rocks encountered so far in Gusev Crater, but also because it contains mineral alterations that extend relatively deep beneath its surface. In fact, as evidenced by its fairly crumbly texture, it is possibly the most highly altered volcanic rock ever studied on Mars. Scientific analysis shows that the rock contains higher levels of the elements sulfur, chlorine, and bromine than are normally encountered in basaltic rocks, such as a rock dubbed 'Humphrey' that Spirit encountered two months after arriving on Mars. Humphrey showed elevated levels of sulfur, chlorine, and bromine only in the outermost 2 millimeters (less than 0.1 inch) of its surface. Clovis shows elevated levels of the same elements along with the associated softness of the rock within a borehole that is 4 times as deep. Scientists hope to compare Clovis to other, less-altered rocks in the vicinity to assess what sort of water-based processes altered the rock. Hypotheses include transport of sulfur, chlorine, and bromine in water vapor in volcanic gases; hydrothermal circulation (flow of volcanically heated water through rock); or saturation in a briny soup containing the same elements. In this image, very fine-grained material from the rock has clumped together by electrostatic attraction and fallen into the borehole. NASA/JPL/Cornell/USGS

  18. Criteria for calculating the efficiency of deep-pleated HEPA filters with aluminum separators during and after design basis accidents

    International Nuclear Information System (INIS)

    Bergman, W.; First, M.W.; Anderson, W.L.

    1995-01-01

    We have reviewed the literature on the performance of HEPA filters under normal and abnormal conditions to establish criteria for calculating the efficiency of HEPA filters in a DOE nonreactor nuclear facility during and after a Design Basis Accident (DBA). This study is only applicable to the standard deep-pleated HEPA filter with aluminum separators as specified in ASME N509[1]. Other HEPA filter designs such as the mini-pleat and separatorless filters are not included in this study. The literature review included the performance of new filters and parameters that may cause deterioration in the filter performance such as filter age, radiation, corrosive chemicals, seismic and rough handling, high temperature, moisture, particle clogging, high air flow and pressure pulses. The deterioration of the filter efficiency depends on the exposure parameters; in severe exposure conditions the filter will be damaged and have a residual efficiency of 0%. There are large gaps and limitations in the data that introduce significant error in the estimates of HEPA filter efficiencies under DBA conditions. Because of this limitation, conservative values of filter efficiency were chosen. The estimation of the efficiency of the HEPA filters under DBA conditions involves three steps: (1) The filter pressure drop and environmental parameters are determined during and after the DBA, (2) Comparing the filter pressure drop to a set of threshold values above which the filter is damaged. There is a different threshold value for each combination of environmental parameters, and (3) Determining the filter efficiency. If the filter pressure drop is greater than the threshold value, the filter is damaged and is assigned 0% efficiency. If the pressure drop is less, then the filter is not damaged and the efficiency is determined from literature values of the efficiency at the environmental conditions

  19. Criteria for calculating the efficiency of deep-pleated HEPA filters with aluminum separators during and after design basis accidents

    Energy Technology Data Exchange (ETDEWEB)

    Bergman, W.; First, M.W.; Anderson, W.L. [Lawrence Livermore National Laboratory, CA (United States)] [and others

    1995-02-01

    We have reviewed the literature on the performance of HEPA filters under normal and abnormal conditions to establish criteria for calculating the efficiency of HEPA filters in a DOE nonreactor nuclear facility during and after a Design Basis Accident (DBA). This study is only applicable to the standard deep-pleated HEPA filter with aluminum separators as specified in ASME N509[1]. Other HEPA filter designs such as the mini-pleat and separatorless filters are not included in this study. The literature review included the performance of new filters and parameters that may cause deterioration in the filter performance such as filter age, radiation, corrosive chemicals, seismic and rough handling, high temperature, moisture, particle clogging, high air flow and pressure pulses. The deterioration of the filter efficiency depends on the exposure parameters; in severe exposure conditions the filter will be damaged and have a residual efficiency of 0%. There are large gaps and limitations in the data that introduce significant error in the estimates of HEPA filter efficiencies under DBA conditions. Because of this limitation, conservative values of filter efficiency were chosen. The estimation of the efficiency of the HEPA filters under DBA conditions involves three steps: (1) The filter pressure drop and environmental parameters are determined during and after the DBA, (2) Comparing the filter pressure drop to a set of threshold values above which the filter is damaged. There is a different threshold value for each combination of environmental parameters, and (3) Determining the filter efficiency. If the filter pressure drop is greater than the threshold value, the filter is damaged and is assigned 0% efficiency. If the pressure drop is less, then the filter is not damaged and the efficiency is determined from literature values of the efficiency at the environmental conditions.

  20. vDNN: Virtualized Deep Neural Networks for Scalable, Memory-Efficient Neural Network Design

    OpenAIRE

    Rhu, Minsoo; Gimelshein, Natalia; Clemons, Jason; Zulfiqar, Arslan; Keckler, Stephen W.

    2016-01-01

    The most widely used machine learning frameworks require users to carefully tune their memory usage so that the deep neural network (DNN) fits into the DRAM capacity of a GPU. This restriction hampers a researcher's flexibility to study different machine learning algorithms, forcing them to either use a less desirable network architecture or parallelize the processing across multiple GPUs. We propose a runtime memory manager that virtualizes the memory usage of DNNs such that both GPU and CPU...

  1. The cost and performance of utility commercial lighting programs. A report from the Database on Energy Efficiency Programs (DEEP) project

    Energy Technology Data Exchange (ETDEWEB)

    Eto, J.; Vine, E.; Shown, L.; Sonnenblick, R.; Payne, C. [Lawrence Berkeley Lab., CA (United States). Energy and Environment Div.

    1994-05-01

    The objective of the Database on Energy Efficiency Programs (DEEP) is to document the measured cost and performance of utility-sponsored, energy-efficiency, demand-side management (DSM) programs. Consistent documentation of DSM programs is a challenging goal because of problems with data consistency, evaluation methodologies, and data reporting formats that continue to limit the usefulness and comparability of individual program results. This first DEEP report investigates the results of 20 recent commercial lighting DSM programs. The report, unlike previous reports of its kind, compares the DSM definitions and methodologies that each utility uses to compute costs and energy savings and then makes adjustments to standardize reported program results. All 20 programs were judged cost-effective when compared to avoided costs in their local areas. At an average cost of 3.9{cents}/kWh, however, utility-sponsored energy efficiency programs are not ``too cheap to meter.`` While it is generally agreed upon that utilities must take active measures to minimize the costs and rate impacts of DSM programs, the authors believe that these activities will be facilitated by industry adoption of standard definitions and reporting formats, so that the best program designs can be readily identified and adopted.

  2. Determination of high-strength materials diamond grinding rational modes

    Science.gov (United States)

    Arkhipov, P. V.; Lobanov, D. V.; Rychkov, D. A.; Yanyushkin, A. S.

    2018-03-01

    The analysis of methods of high-strength materials abrasive processing is carried out. This method made it possible to determine the necessary directions and prospects for the development of shaping combined methods. The need to use metal bonded diamond abrasive tools in combination with a different kind of energy is noted to improve the processing efficiency and reduce the complexity of operations. The complex of experimental research on revealing the importance of mechanical and electrical components of cutting regimes, on the cutting ability of diamond tools, as well as the need to reduce the specific consumption of an abrasive wheel as one of the important economic indicators of the processing process is performed. It is established that combined diamond grinding with simultaneous continuous correction of the abrasive wheel contributes to an increase in the cutting ability of metal bonded diamond abrasive tools when processing high-strength materials by an average of 30% compared to diamond grinding. Particular recommendations on the designation of technological factors are developed depending on specific production problems.

  3. A Simple and Efficient RNA Extraction Method from Deep-Sea Hydrothermal Vent Chimney Structures.

    Science.gov (United States)

    Muto, Hisashi; Takaki, Yoshihiro; Hirai, Miho; Mino, Sayaka; Sawayama, Shigeki; Takai, Ken; Nakagawa, Satoshi

    2017-12-27

    RNA-based microbiological analyses, e.g., transcriptome and reverse transcription-quantitative PCR, require a relatively large amount of high quality RNA. RNA-based analyses on microbial communities in deep-sea hydrothermal environments often encounter methodological difficulties with RNA extraction due to the presence of unique minerals in and the low biomass of samples. In the present study, we assessed RNA extraction methods for deep-sea vent chimneys that had complex mineral compositions. Mineral-RNA adsorption experiments were conducted using mock chimney minerals and Escherichia coli total RNA solution, and showed that detectable RNA significantly decreased possibly due to adsorption onto minerals. This decrease in RNA was prevented by the addition of sodium tripolyphosphate (STPP), deoxynucleotide triphosphates (dNTPs), salmon sperm DNA, and NaOH. The addition of STPP was also effective for RNA extraction from the mixture of E. coli cells and mock chimney minerals when TRIzol reagent and the RNeasy column were used, but not when the RNeasy PowerSoil total RNA kit was used. A combination of STPP, TRIzol reagent, the RNeasy column, and sonication resulted in the highest RNA yield from a natural chimney. This indirect extraction procedure is simple, rapid, inexpensive, and may be used for large-scale RNA extraction.

  4. An Efficient Implementation of Deep Convolutional Neural Networks for MRI Segmentation.

    Science.gov (United States)

    Hoseini, Farnaz; Shahbahrami, Asadollah; Bayat, Peyman

    2018-02-27

    Image segmentation is one of the most common steps in digital image processing, classifying a digital image into different segments. The main goal of this paper is to segment brain tumors in magnetic resonance images (MRI) using deep learning. Tumors having different shapes, sizes, brightness and textures can appear anywhere in the brain. These complexities are the reasons to choose a high-capacity Deep Convolutional Neural Network (DCNN) containing more than one layer. The proposed DCNN contains two parts: architecture and learning algorithms. The architecture and the learning algorithms are used to design a network model and to optimize parameters for the network training phase, respectively. The architecture contains five convolutional layers, all using 3 × 3 kernels, and one fully connected layer. Due to the advantage of using small kernels with fold, it allows making the effect of larger kernels with smaller number of parameters and fewer computations. Using the Dice Similarity Coefficient metric, we report accuracy results on the BRATS 2016, brain tumor segmentation challenge dataset, for the complete, core, and enhancing regions as 0.90, 0.85, and 0.84 respectively. The learning algorithm includes the task-level parallelism. All the pixels of an MR image are classified using a patch-based approach for segmentation. We attain a good performance and the experimental results show that the proposed DCNN increases the segmentation accuracy compared to previous techniques.

  5. Investigation on Surface Roughness in Cylindrical Grinding

    Science.gov (United States)

    Rudrapati, Ramesh; Bandyopadhyay, Asish; Pal, Pradip Kumar

    2011-01-01

    Cylindrical grinding is a complex machining process. And surface roughness is often a key factor in any machining process while considering the machine tool or machining performance. Further, surface roughness is one of the measures of the technological quality of the product and is a factor that greatly influences cost and quality. The present work is related to some aspects of surface finish in the context of traverse-cut cylindrical grinding. The parameters considered have been: infeed, longitudinal feed and work speed. Taguchi quality design is used to design the experiments and to identify the significantly import parameter(s) affecting the surface roughness. By utilization of Response Surface Methodology (RSM), second order differential equation has been developed and attempts have also been made for optimization of the process in the context of surface roughness by using C- programming.

  6. Ultra-Lightweight High Efficiency Nanostructured Materials and Coatings for Deep Space Mission Environments, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — NanoSonic has developed a nanostructured spray self-assembly manufacturing method that has resulted in ultra-lightweight ( 1000%), and multi-layer, high efficiency...

  7. Highly Efficient Closed-Loop CO2 Removal System for Deep-Space ECLSS, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — TDA Research Inc.(TDA) in collaboration with University of Puerto Rico ? Mayaguez (UPRM is proposing to develop a highly efficient CO2 removal system based on UPRM...

  8. INTRODUCTION TO THE ANALYSIS OF THE MECHANICS OF THE DIAMOND GRINDING PROCESS WITH THE ACCOUNT OF WEAR OF WHEEL GRAINS

    Directory of Open Access Journals (Sweden)

    Feodor NOVIKOV

    2017-12-01

    Full Text Available The work is devoted to the theoretical analysis of the mechanics of the diamond grinding process, taking into account the wear of the wheel grains for scientifically based choice of optimal processing conditions. A multiplicative probabilistic approach to the generalization of the cutting profile of a diamond grinding wheel in its consideration in a state of some steady wear during processing is considered. This is achieved by working the wheel in a mode of properly established self-sharpening or with the use of effective dressing methods. In this case, the linear wear of individual grains of diamond abrasive located on the working surface of the grinding wheel and opened to mechanical contact with the material being processed is assumed to proportionally to the depth of the introduction of grain into it. The analytical dependence of the maximum thickness of the cut is presented, and the relationship between the maximum grain wear and the accepted universal relative characteristic of the steady wear with the operational parameters of the tool and the grinding mode is shown. The obtained results can be used in the development of analytical models of processing productivity and microgeometric engineering of the treated surface, new approaches to increasing the efficiency of diamond grinding. The research is based on modern technical possibilities of controlling the state of the cutting relief of diamond-abrasive tools, especially in electro-physical-mechanical grinding technologies, for example, using the diamond-spark method developed at the Kharkov Polytechnic Institute.

  9. Processing equipment for grinding of building powders

    Science.gov (United States)

    Fediuk, R. S.; Ibragimov, R. A.; Lesovik, V. S.; Pak, A. A.; Krylov, V. V.; Poleschuk, M. M.; Stoyushko, N. Y.; Gladkova, N. A.

    2018-03-01

    In the article questions of mechanical grinding up to nanosize of building powder materials are considered. In the process of mechanoactivation of the composite binder, active molecules of cement minerals arise when molecular packets are destroyed in the areas of defects and loosening of the metastable phase during decompensation of intermolecular forces. The process is accompanied by a change in the kinetics of hardening Portland cement. Mechanical processes in the grinding of mineral materials cause, together with an increase in their surface energy, the growth of the isobaric potential of the powders and, accordingly, their chemical activity, which also contributes to high adhesion strength when they come into contact with binders. Thus, a set of measures for mechanical activation allows more fully use the mass of components of the filled cement systems and regulate their properties. At relatively low costs, it is possible to provide an impressive and, importantly, easily repeatable in production conditions result. It is revealed that the use of a vario-planetary mill allows to achieve the best results on grinding the powder building materials.

  10. System Analysis of Flat Grinding Process with Wheel Face

    Directory of Open Access Journals (Sweden)

    T. N. Ivanova

    2014-01-01

    Full Text Available The paper presents a conducted system analysis of the flat grinding wheel face, considers the state parameters, input and output variables of subsystems, namely: machine tool, workpiece, grinding wheel, cutting fluids, and the contact area. It reveals the factors influencing the temperature and power conditions for the grinding process.Aim: conducting the system analysis of the flat grinding process with wheel face expects to enable a development of the system of grinding process parameters as a technical system, which will make it possible to evaluate each parameter individually and implement optimization of the entire system.One of the most important criteria in defining the optimal process conditions is the grinding temperature, which, to avoid defects appearance of on the surface of component, should not exceed the critical temperature values to be experimentally determined. The temperature criterion can be useful for choosing the conditions for the maximum defect-free performance of the mechanical face grinding. To define the maximum performance of defect-free grinding can also use other criteria such as a critical power density, indirectly reflecting the allowable thermal stress grinding process; the structure of the ground surface, which reflects the presence or absence of a defect layer, which is determined after the large number of experiments; flow range of the diamond layer.Optimal conditions should not exceed those of defect-free grinding. It is found that a maximum performance depends on the characteristics of circles and grade of processed material, as well as on the contact area and grinding conditions. Optimal performance depends on the diamond value (cost and specific consumption of diamonds in a circle.Above criteria require formalization as a function of the variable parameters of the grinding process. There is an option for the compromise of inter-criteria optimality, thereby providing a set of acceptable solutions, from

  11. The study of sub-surface damage distributions during grinding process on different abrasion materials

    Science.gov (United States)

    Kuo, Ching-Hsiang; Huang, Chien-Yao; Yu, Zong-Ru; Shu, Shyu-Cheng; Chang, Keng-Shou; Hsu, Wei-Yao

    2017-10-01

    The grinding process is the primary technology for curvature generation (CG) on glass optics. The higher material removal rate (MRR) leads to deeper sub-surface damage (SSD) on lens surface. The SSD must be removed by following lapping and polishing processes to ensure the lens quality. However, these are not an easy and an efficient process to remove the SSD from ground surface directly for aspheric surfaces with tens or hundreds microns departure from bestfit- sphere (BFS). An efficient fabrication procedure for large aspheric departure on glass materials must be considered. We propose 3-step fabrication procedures for aspheric surface with larger departure. 1st step is to generate a specific aspheric surface with depth less than 10 μm of SSD residual. 2nd step is to remove SSD and keep the aspheric form by using Zeeko polisher with higher MRR pad. Final step is to figure and finish the aspheric surface by using QED MRF machine. In this study, we focus on the 1st step to investigate the residual depth of SSD after grinding process on different abrasion materials. The materials of tested part are fused silica, S-NPH2, and S-PHM52. The cross grinding would be configured and depth of SSD/surface roughness would be evaluated in this study. The characteristic of SSD could be observed after etching by confocal microscope. The experimental results show the depth of SSD below 31.1 μm with #400 grinding wheel. And the near 10 μm depth of SSD would be achieved with #1,000 grinding wheel. It means the aspherization polishing on large parts with large departure from best fit sphere would be replaced. The fabrication of large aspheric part would be efficient.

  12. DEEP-SaM - Energy-Efficient Provisioning Policies for Computing Environments

    Science.gov (United States)

    Bodenstein, Christian; Püschel, Tim; Hedwig, Markus; Neumann, Dirk

    The cost of electricity for datacenters is a substantial operational cost that can and should be managed, not only for saving energy, but also due to the ecologic commitment inherent to power consumption. Often, pursuing this goal results in chronic underutilization of resources, a luxury most resource providers do not have in light of their corporate commitments. This work proposes, formalizes and numerically evaluates DEEP-Sam, for clearing provisioning markets, based on the maximization of welfare, subject to utility-level dependant energy costs and customer satisfaction levels. We focus specifically on linear power models, and the implications of the inherent fixed costs related to energy consumption of modern datacenters and cloud environments. We rigorously test the model by running multiple simulation scenarios and evaluate the results critically. We conclude with positive results and implications for long-term sustainable management of modern datacenters.

  13. Flexible deep-ultraviolet light-emitting diodes for significant improvement of quantum efficiencies by external bending

    KAUST Repository

    Shervin, Shahab; Oh, Seung Kyu; Park, Hyun Jung; Lee, Keon Hwa; Asadirad, Mojtaba; Kim, Seung Hwan; Kim, Jeomoh; Pouladi, Sara; Lee, Sung-Nam; Li, Xiaohang; Kwak, Joon-Seop; Ryou, Jae-Hyun

    2018-01-01

    Deep ultraviolet (DUV) light at the wavelength range of 250‒280 nm (UVC spectrum) is essential for numerous applications such as sterilization, purification, sensing, and communication. III-nitride-based DUV light-emitting diodes (DUV LEDs), like other solid-state lighting sources, offer a great potential to replace the conventional gas-discharged lamps with short lifetimes and toxic-element-bearing nature. However, unlike visible LEDs, the DUV LEDs are still suffering from low quantum efficiencies (QEs) and low optical output powers. In this work, reported is a new route to improve QEs of AlGaN-based DUV LEDs using mechanical flexibility of recently developed bendable thin-film structures. Numerical studies show that electronic band structures of AlGaN heterostructures and resulting optical and electrical characteristics of the devices can be significantly modified by external bending through active control of piezoelectric polarization. Internal quantum efficiency (IQE) is enhanced higher than three times, when the DUV LEDs are moderately bent to induce in-plane compressive strain in the heterostructure. Furthermore, efficiency droop at high injection currents is mitigated and turn-on voltage of diodes decreases with the same bending condition. The concept of bendable DUV LEDs with a controlled external strain can provide a new path for high-output-power and high-efficiency devices.

  14. Flexible deep-ultraviolet light-emitting diodes for significant improvement of quantum efficiencies by external bending

    KAUST Repository

    Shervin, Shahab

    2018-01-26

    Deep ultraviolet (DUV) light at the wavelength range of 250‒280 nm (UVC spectrum) is essential for numerous applications such as sterilization, purification, sensing, and communication. III-nitride-based DUV light-emitting diodes (DUV LEDs), like other solid-state lighting sources, offer a great potential to replace the conventional gas-discharged lamps with short lifetimes and toxic-element-bearing nature. However, unlike visible LEDs, the DUV LEDs are still suffering from low quantum efficiencies (QEs) and low optical output powers. In this work, reported is a new route to improve QEs of AlGaN-based DUV LEDs using mechanical flexibility of recently developed bendable thin-film structures. Numerical studies show that electronic band structures of AlGaN heterostructures and resulting optical and electrical characteristics of the devices can be significantly modified by external bending through active control of piezoelectric polarization. Internal quantum efficiency (IQE) is enhanced higher than three times, when the DUV LEDs are moderately bent to induce in-plane compressive strain in the heterostructure. Furthermore, efficiency droop at high injection currents is mitigated and turn-on voltage of diodes decreases with the same bending condition. The concept of bendable DUV LEDs with a controlled external strain can provide a new path for high-output-power and high-efficiency devices.

  15. 2-(2-Hydroxyphenyl)imidazole-based four-coordinate organoboron compounds with efficient deep blue photoluminescence and electroluminescence.

    Science.gov (United States)

    Zhang, Zhenyu; Zhang, Zuolun; Zhang, Hongyu; Wang, Yue

    2017-12-19

    Two new four-coordinate organoboron compounds with 2-(2-hydroxyphenyl)imidazole derivatives as the chelating ligands have been synthesized. They possess high thermal stability and are able to form an amorphous glass state. Crystallographic analyses indicate that the differences in ligand structure cause the change of ππ stacking character. The CH 2 Cl 2 solutions and thin films of these compounds display bright blue emission, and these compounds have appropriate HOMO and LUMO energy levels for carrier injection in OLEDs. By utilizing the good thermal and luminescent properties, as well as the proper frontier orbital energy levels, bright non-doped OLEDs with a simple structure have been realized. Notably, these simple devices show deep blue electroluminescence with the Commission Internationale de l'Éclairage (CIE) coordinate of ca. (0.16, 0.08), which is close to the CIE coordinate of (0.14, 0.08) for standard blue defined by the National Television System Committee. In addition, one of the devices exhibits good performance, showing brightness, current efficiency, power efficiency and external quantum efficiency up to 2692 cd m -2 , 2.50 cd A -1 , 1.81 lm W -1 and 3.63%, respectively. This study not only provides good deep-blue emitting OLED materials that are rarely achieved by using four-coordinate organoboron compounds, but also allows a deeper understanding of the structure-property relationship of 2-(2-hydroxyphenyl)imidazole-based boron complexes, which benefits the further structural design of this type of material.

  16. Elucidating Grinding Mechanism by Theoretical and Experimental Investigations

    Directory of Open Access Journals (Sweden)

    AMM Sharif Ullah

    2018-02-01

    Full Text Available Grinding is one of the essential manufacturing processes for producing brittle or hard materials-based precision parts (e.g., optical lenses. In grinding, a grinding wheel removes the desired amount of material by passing the same area on the workpiece surface multiple times. How the topography of a workpiece surface evolves with these passes is thus an important research issue, which has not yet been addressed elaborately. The present paper tackles this issue from both the theoretical and the experimental points of view. In particular, this paper presents the results of experimental and theoretical investigations on the multi-pass surface grinding operations where the workpiece surface is made of glass and the grinding wheel consists of cBN abrasive grains. Both investigations confirm that a great deal of stochasticity is involved in the grinding mechanism, and the complexity of the workpiece surface gradually increases along with the number of passes.

  17. Elucidating Grinding Mechanism by Theoretical and Experimental Investigations.

    Science.gov (United States)

    Ullah, Amm Sharif; Caggiano, Alessandra; Kubo, Akihiko; Chowdhury, M A K

    2018-02-09

    Grinding is one of the essential manufacturing processes for producing brittle or hard materials-based precision parts (e.g., optical lenses). In grinding, a grinding wheel removes the desired amount of material by passing the same area on the workpiece surface multiple times. How the topography of a workpiece surface evolves with these passes is thus an important research issue, which has not yet been addressed elaborately. The present paper tackles this issue from both the theoretical and the experimental points of view. In particular, this paper presents the results of experimental and theoretical investigations on the multi-pass surface grinding operations where the workpiece surface is made of glass and the grinding wheel consists of cBN abrasive grains. Both investigations confirm that a great deal of stochasticity is involved in the grinding mechanism, and the complexity of the workpiece surface gradually increases along with the number of passes.

  18. Nitrogen Fertilizer Deep Placement for Increased Grain Yield and Nitrogen Recovery Efficiency in Rice Grown in Subtropical China

    Directory of Open Access Journals (Sweden)

    Meng Wu

    2017-07-01

    Full Text Available Field plot experiments were conducted over 3 years (from April 2014 to November 2016 in a double-rice (Oryza sativa L. cropping system in subtropical China to evaluate the effects of N fertilizer placement on grain yield and N recovery efficiency (NRE. Different N application methods included: no N application (CK; N broadcast application (NBP; N and NPK deep placement (NDP and NPKDP, respectively. Results showed that grain yield and apparent NRE significantly increased for NDP and NPKDP as compared to NBP. The main reason was that N deep placement (NDP increased the number of productive panicle per m-2. To further evaluate the increase, a pot experiment was conducted to understand the N supply in different soil layers in NDP during the whole rice growing stage and a 15N tracing technique was used in a field experiment to investigate the fate of urea-15N in the rice–soil system during rice growth and at maturity. The pot experiment indicated that NDP could maintain a higher N supply in deep soil layers than N broadcast for 52 days during rice growth. The 15N tracing study showed that NDP could maintain much higher fertilizer N in the 5–20 cm soil layer during rice growth and could induce plant to absorb more N from fertilizer and soil than NBP, which led to higher NRE. One important finding was that NDP and NPKDP significantly increased fertilizer NRE but did not lead to N declined in soil compared to NBP. Compared to NPK, NPKDP induced rice plants to absorb more fertilizer N rather than soil N.

  19. Harnessing wake vortices for efficient collective swimming via deep reinfrcement learning

    Science.gov (United States)

    Verma, Siddartha; Novati, Guido; Koumoutsakos, Petros; ChairComputing Science Team

    2017-11-01

    Collective motion may bestow evolutionary advantages to a number of animal species. Soaring flocks of birds, teeming swarms of insects, and swirling masses of schooling fish, all to some extent enjoy anti-predator benefits, increased foraging success, and enhanced problem-solving abilities. Coordinated activity may also provide energetic benefits, as in the case of large groups of fish where swimmers exploit unsteady flow-patterns generated in the wake. Both experimental and computational investigations of such scenarios are hampered by difficulties associated with studying multiple swimmers. Consequentially, the precise energy-saving mechanisms at play remain largely unknown. We combine high-fidelity numerical simulations of multiple, self propelled swimmers with novel deep reinforcement learning algorithms to discover optimal ways for swimmers to interact with unsteady wakes, in a fully unsupervised manner. We identify optimal flow-interaction strategies devised by the resulting autonomous swimmers, and use it to formulate an effective control-logic. We demonstrate, via 3D simulations of controlled groups that swimmers exploiting the learned strategy exhibit a significant reduction in energy-expenditure. ERC Advanced Investigator Award 341117.

  20. Deep Eutectic Solvent Aqueous Solutions as Efficient Media for the Solubilization of Hardwood Xylans.

    Science.gov (United States)

    Morais, Eduarda S; Mendonça, Patrícia V; Coelho, Jorge F J; Freire, Mara G; Freire, Carmen S R; Coutinho, João A P; Silvestre, Armando J D

    2018-02-22

    This work contributes to the development of integrated lignocellulosic-based biorefineries by the pioneering exploitation of hardwood xylans by solubilization and extraction in deep eutectic solvents (DES). DES formed by choline chloride and urea or acetic acid were initially evaluated as solvents for commercial xylan as a model compound. The effects of temperature, molar ratio, and concentration of the DES aqueous solutions were evaluated and optimized by using a response surface methodology. The results obtained demonstrated the potential of these solvents, with 328.23 g L -1 of xylan solubilization using 66.7 wt % DES in water at 80 °C. Furthermore, xylans could be recovered by precipitation from the DES aqueous media in yields above 90 %. The detailed characterization of the xylans recovered after solubilization in aqueous DES demonstrated that 4-O-methyl groups were eliminated from the 4-O-methylglucuronic acids moieties and uronic acids (15 %) were cleaved from the xylan backbone during this process. The similar M w values of both pristine and recovered xylans confirmed the success of the reported procedure. DES recovery in four additional extraction cycles was also demonstrated. Finally, the successful extraction of xylans from Eucalyptus globulus wood by using aqueous solutions of DES was demonstrated. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Fine grinding of brittle minerals and materials by jet mill

    OpenAIRE

    Lek Sikong; Kalayanee Kooptanond; Noparit Morasut; Thammasak Pongprasert

    2008-01-01

    Various variables affecting grinding, such as air pressure, minerals or materials hardness, feed size were investigated.The limitations of grinding of gypsum, barite, ilmenite, quartz and ferrosilicon were also elucidated by means of particlefineness size distribution and morphology of ground products. It was found that:1) The density of particles, which are in the grinding zone affects the product fineness, i.e. higher feed rate resultsin a larger product size. The appropriate feed rate is s...

  2. In-situ roundness measurement and correction for pin journals in oscillating grinding machines

    Science.gov (United States)

    Yu, Hongxiang; Xu, Mengchen; Zhao, Jie

    2015-01-01

    In the mass production of vehicle-engine crankshafts, pin chasing grinding using oscillating grinding machines is a widely accepted method to achieve flexible and efficient performance. However, the eccentric movement of pin journals makes it difficult to develop an in-process roundness measurement scheme for the improvement of contour precision. Here, a new in-situ roundness measurement strategy is proposed with high scanning speed. The measuring mechanism is composed of a V-block and an adaptive telescopic support. The swing pattern of the telescopic support and the V-block is analysed for an equal angle-interval signal sampling. Hence roundness error signal is extracted in frequency domain using a small-signal model of the V-block roundness measurement method and the Fast Fourier Transformation. To implement the roundness data in the CNC coordinate system of an oscillating grinding machine, a transformation function is derived according to the motion model of pin chasing grinding methodology. Computer simulation reveals the relationship between the rotational position of the crankshaft component and the scanning angle of the displacement probe on the V-block, as well as the influence introduced by the rotation centre drift. Prototype investigation indicates the validity of the theoretical analysis and the feasibility of the new strategy.

  3. Rubber lining design for grinding mills: influence on economy and capacity

    Energy Technology Data Exchange (ETDEWEB)

    Nillson, G

    1979-11-01

    There is a difference in design parameters between steel linings and rubber linings for grinding mills. The basic design parameters for rubber are described and a comparison is made between steel and rubber in different applications. If a rubber lining is correctly designed, it will give at least the same capacity as any other type of lining. A rubber lining can often be made thinner than other types of lining and, in such cases, the increased mill diameter will increase the capacity. What has been said above regarding capacity applies equally to grinding efficiency. The grind can sometimes be changed by altering the lifter height and lifter profile. Rubber linings of the correct quality and design will always give improved lining economy, except for large primary ball mills. We trust that new designs and rubber qualities will change the picture in the future. What is said about lining economy is especially true when taking reduced downtime and maintenance into consideration. The lining must be designed to reduce sliding over the shell, which leads to heavy wear. When used for dry grinding, the adverse effects of temperature must be observed.

  4. Challenges associated with the design of underground grinding plant at McArthur River project

    International Nuclear Information System (INIS)

    Jamrozek, J.S.

    2000-01-01

    McArthur River is an unique high grade uranium underground mine. Ore grinding and thickening are part of the underground operation. The grinding circuit is designed to operate in conditions different from conventional plant environments. Design of the grinding plant was a collective effort of a multi-disciplinary engineering team closely cooperating with project operating personnel. The equipment had to be selected to reflect widely varying ore properties. A user-friendly plant layout provides access to equipment inspections, services, and the delivery of necessary components. The size of the grinding chamber was limited in order to keep the rock stress levels within allowable values. All underground equipment brought to the construction site was restricted in size and weight. Plant construction faced limited storage space underground, tight erection sequencing, and schedule. Plant ventilation is a critical design feature. It efficiently removes radioactive dust from work areas, eliminates stagnant air pockets, and separates clean air from contaminated air areas. Radiation shielding on the equipment is designed to correspond with operational and maintenance functions. Plant operation is remotely controlled and requires little attendance. Video cameras are used on critical equipment and in controlled access areas. An extensive program of preventive and predictive maintenance allows highly reliable plant operation. (author)

  5. Algorithmic design of a noise-resistant and efficient closed-loop deep brain stimulation system: A computational approach.

    Directory of Open Access Journals (Sweden)

    Sofia D Karamintziou

    Full Text Available Advances in the field of closed-loop neuromodulation call for analysis and modeling approaches capable of confronting challenges related to the complex neuronal response to stimulation and the presence of strong internal and measurement noise in neural recordings. Here we elaborate on the algorithmic aspects of a noise-resistant closed-loop subthalamic nucleus deep brain stimulation system for advanced Parkinson's disease and treatment-refractory obsessive-compulsive disorder, ensuring remarkable performance in terms of both efficiency and selectivity of stimulation, as well as in terms of computational speed. First, we propose an efficient method drawn from dynamical systems theory, for the reliable assessment of significant nonlinear coupling between beta and high-frequency subthalamic neuronal activity, as a biomarker for feedback control. Further, we present a model-based strategy through which optimal parameters of stimulation for minimum energy desynchronizing control of neuronal activity are being identified. The strategy integrates stochastic modeling and derivative-free optimization of neural dynamics based on quadratic modeling. On the basis of numerical simulations, we demonstrate the potential of the presented modeling approach to identify, at a relatively low computational cost, stimulation settings potentially associated with a significantly higher degree of efficiency and selectivity compared with stimulation settings determined post-operatively. Our data reinforce the hypothesis that model-based control strategies are crucial for the design of novel stimulation protocols at the backstage of clinical applications.

  6. Algorithmic design of a noise-resistant and efficient closed-loop deep brain stimulation system: A computational approach.

    Science.gov (United States)

    Karamintziou, Sofia D; Custódio, Ana Luísa; Piallat, Brigitte; Polosan, Mircea; Chabardès, Stéphan; Stathis, Pantelis G; Tagaris, George A; Sakas, Damianos E; Polychronaki, Georgia E; Tsirogiannis, George L; David, Olivier; Nikita, Konstantina S

    2017-01-01

    Advances in the field of closed-loop neuromodulation call for analysis and modeling approaches capable of confronting challenges related to the complex neuronal response to stimulation and the presence of strong internal and measurement noise in neural recordings. Here we elaborate on the algorithmic aspects of a noise-resistant closed-loop subthalamic nucleus deep brain stimulation system for advanced Parkinson's disease and treatment-refractory obsessive-compulsive disorder, ensuring remarkable performance in terms of both efficiency and selectivity of stimulation, as well as in terms of computational speed. First, we propose an efficient method drawn from dynamical systems theory, for the reliable assessment of significant nonlinear coupling between beta and high-frequency subthalamic neuronal activity, as a biomarker for feedback control. Further, we present a model-based strategy through which optimal parameters of stimulation for minimum energy desynchronizing control of neuronal activity are being identified. The strategy integrates stochastic modeling and derivative-free optimization of neural dynamics based on quadratic modeling. On the basis of numerical simulations, we demonstrate the potential of the presented modeling approach to identify, at a relatively low computational cost, stimulation settings potentially associated with a significantly higher degree of efficiency and selectivity compared with stimulation settings determined post-operatively. Our data reinforce the hypothesis that model-based control strategies are crucial for the design of novel stimulation protocols at the backstage of clinical applications.

  7. Grinding tool for making hemispherical bores in hard materials

    Science.gov (United States)

    Duran, E.L.

    1985-04-03

    A grinding tool for forming hemispherical bores in hard materials such as boron carbide. The tool comprises a hemicircular grinding bit, formed of a metal bond diamond matrix, which is mounted transversely on one end of a tubular tool shaft. The bit includes a spherically curved outer edge surface which is the active grinding surface of the tool. Two coolant fluid ports on opposite sides of the bit enable introduction of coolant fluid through the bore of the tool shaft so as to be emitted adjacent the opposite sides of the grinding bit, thereby providing optimum cooling of both the workpiece and the bit.

  8. Dopantless Diodes for Efficient Mid/deep UV LEDs and Lasers - Topic 4.2 Optoelectronics

    Science.gov (United States)

    2017-09-12

    UVB/UVC solid state emitters is a rapidly growing market – UV curing of adhesives – Water disinfection – Chemical Agent detection • Replacement of...recombination • Electron leakage • Junction heating ~3.5× EL in TJ LEDS ~2× EL @ 180 A/cm2 DC measurements; 0.1mm×0.1mm 29 Increased wall plug efficiency 0...market – UV curing of adhesives – Water disinfection – Chemical Agent detection • Replacement of bulky, toxic Hg arc lamps • Applications require high

  9. Utility of an unitary-shredding method to evaluate the conditions and selection of constructional features during grinding

    Directory of Open Access Journals (Sweden)

    Macko Marek

    2018-01-01

    Full Text Available In order to evaluate and improve the efficiency of the process of grinding, various investigations are conducted, based on the relevant research methodology. One of them is the method in which the crushed sample is subjected to single stroke loads. On this basis, the influence of the geometric features of the chipper system and the dynamic process on the efficiency of the grinding is determined. Charpy hammers instrument were used to perform these modifications so that the momentary force of the resistance could be recorded with varying sample alignment, blade geometry changes and others. In addition, it was proposed to use a super fast camera (up to 1200 fps to record the deformation of the sample and its destruction, in order to interpretation the burdens there. Under such idealized conditions, a range of variables has been identified that significantly affect the reduction of energy demand during grinding.

  10. Efficient absorption of SO{sub 2} with low-partial pressures by environmentally benign functional deep eutectic solvents

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Kai; Ren, Shuhang [State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing, 100029 (China); Hou, Yucui [Department of Chemistry, Taiyuan Normal University, Taiyuan, 030031 (China); Wu, Weize, E-mail: wzwu@mail.buct.edu.cn [State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing, 100029 (China)

    2017-02-15

    Graphical abstract: Environmentally benign deep eutectic solvents (DESs) based on betaine or L-carnitine with ethylene glycol were designed with a function and used to efficiently capture SO{sub 2} with low partial pressures. - Highlights: • Deep eutectic solvents (DESs) were designed with a function to absorb low-conc. SO{sub 2}. • Betaine(Bet) and L-carnitine(L-car) with a functional group were used as H-bond acceptor. • Bet + ethylene glycol (EG) DES and L-car + EG DES are environmentally benign. • L-car + EG DES can absorb 0.644 mol SO{sub 2} per mole L-car (0.37% SO{sub 2}). • L-car + EG DES is a promising absorbent for SO{sub 2} capture. - Abstract: Sulfur dioxide (SO{sub 2}) emitted from the burning of fossil fuels is one of the main air contaminants. In this work, we found that environmentally benign solvents, deep eutectic solvents (DESs) could be designed with a function to absorb low-partial pressure SO{sub 2} from simulated flue gas. Two kinds of biodegradable functional DESs based on betaine (Bet) and L-carnitine (L-car) as hydrogen bond accepters (HBA) and ethylene glycol (EG) as a hydrogen bond donor (HBD) were prepared with mole ratios of HBA to HBD from 1:3 to 1:5, and they were investigated to absorb SO{sub 2} with different partial pressures at various temperatures. The results showed that the two DESs could absorb low-partial pressure SO{sub 2} efficiently. SO{sub 2} absorption capacities of the DESs with HBA/HBD mole ratio of 1:3 were 0.332 mol SO{sub 2}/mol HBA for Bet + EG DES and 0.820 mol SO{sub 2}/mol HBA for L-car + EG DES at 40 °C with a SO{sub 2} partial pressure of 0.02 atm. In addition, the regeneration experiments demonstrated that the absorption capacities of DESs did not change after five absorption and desorption cycles. Furthermore, the absorption mechanism of SO{sub 2} by DESs was studied by FT-IR, {sup 1}H NMR and {sup 13}C NMR spectra. It was found that there are strong acid–base interactions between SO{sub 2} and

  11. Efficient absorption of SO_2 with low-partial pressures by environmentally benign functional deep eutectic solvents

    International Nuclear Information System (INIS)

    Zhang, Kai; Ren, Shuhang; Hou, Yucui; Wu, Weize

    2017-01-01

    Graphical abstract: Environmentally benign deep eutectic solvents (DESs) based on betaine or L-carnitine with ethylene glycol were designed with a function and used to efficiently capture SO_2 with low partial pressures. - Highlights: • Deep eutectic solvents (DESs) were designed with a function to absorb low-conc. SO_2. • Betaine(Bet) and L-carnitine(L-car) with a functional group were used as H-bond acceptor. • Bet + ethylene glycol (EG) DES and L-car + EG DES are environmentally benign. • L-car + EG DES can absorb 0.644 mol SO_2 per mole L-car (0.37% SO_2). • L-car + EG DES is a promising absorbent for SO_2 capture. - Abstract: Sulfur dioxide (SO_2) emitted from the burning of fossil fuels is one of the main air contaminants. In this work, we found that environmentally benign solvents, deep eutectic solvents (DESs) could be designed with a function to absorb low-partial pressure SO_2 from simulated flue gas. Two kinds of biodegradable functional DESs based on betaine (Bet) and L-carnitine (L-car) as hydrogen bond accepters (HBA) and ethylene glycol (EG) as a hydrogen bond donor (HBD) were prepared with mole ratios of HBA to HBD from 1:3 to 1:5, and they were investigated to absorb SO_2 with different partial pressures at various temperatures. The results showed that the two DESs could absorb low-partial pressure SO_2 efficiently. SO_2 absorption capacities of the DESs with HBA/HBD mole ratio of 1:3 were 0.332 mol SO_2/mol HBA for Bet + EG DES and 0.820 mol SO_2/mol HBA for L-car + EG DES at 40 °C with a SO_2 partial pressure of 0.02 atm. In addition, the regeneration experiments demonstrated that the absorption capacities of DESs did not change after five absorption and desorption cycles. Furthermore, the absorption mechanism of SO_2 by DESs was studied by FT-IR, "1H NMR and "1"3C NMR spectra. It was found that there are strong acid–base interactions between SO_2 and −COO"− on HBA.

  12. Learning Activity Packets for Grinding Machines. Unit I--Grinding Machines.

    Science.gov (United States)

    Oklahoma State Board of Vocational and Technical Education, Stillwater. Curriculum and Instructional Materials Center.

    This learning activity packet (LAP) is one of three that accompany the curriculum guide on grinding machines. It outlines the study activities and performance tasks for the first unit of this curriculum guide. Its purpose is to aid the student in attaining a working knowledge of this area of training and in achieving a skilled or moderately…

  13. Learning Activity Packets for Grinding Machines. Unit II--Surface Grinding.

    Science.gov (United States)

    Oklahoma State Board of Vocational and Technical Education, Stillwater. Curriculum and Instructional Materials Center.

    This learning activity packet (LAP) is one of three that accompany the curriculum guide on grinding machines. It outlines the study activities and performance tasks for the second unit of this curriculum guide. Its purpose is to aid the student in attaining a working knowledge of this area of training and in achieving a skilled or moderately…

  14. Learning Activity Packets for Grinding Machines. Unit III--Cylindrical Grinding.

    Science.gov (United States)

    Oklahoma State Board of Vocational and Technical Education, Stillwater. Curriculum and Instructional Materials Center.

    This learning activity packet (LAP) is one of three that accompany the curriculum guide on grinding machines. It outlines the study activities and performance tasks for the third unit of this curriculum guide. Its purpose is to aid the student in attaining a working knowledge of this area of training and in achieving a skilled or moderately…

  15. Quenching simulation of steel grinding balls

    Energy Technology Data Exchange (ETDEWEB)

    Zapata-Hernandez, O.; Reyes, L. A.; Camurri, C.; Carrasco, C.; Garza-Monte-de-Oca, F.; Colas, R.

    2015-07-01

    The phase transformations of high carbon steel during quenching and equalizing were modelled using commercial computer packages based on the finite element method and the kinetic transformation of steel. The model was used to predict the temperature and microstructural changes taking place within balls of two different sizes that are used for grinding mineral ores. A good correlation between the temperatures measured by inserted thermocouples and those predicted by the model was obtained after modifying the thermal conductivity of the steel within the temperature domain at which mixed phases are present. The phase transformations predicted were confirmed by metallographic analyses. (Author)

  16. The Efficiency of an Active Generator in the Case of a Deep Foundation Location

    Directory of Open Access Journals (Sweden)

    Herbut Aneta

    2017-03-01

    Full Text Available This paper presents a concept for vibration-mitigation techniques with the potential to reduce ground vibration amplitudes by applying an additional vibration source. The idea of an additional generator is verified in the case of an impact load for the points located on the ground surface and below it. Equations of motion for the damped transversally isotropic ground model with the absorbing boundary conditions are presented and numerically integrated using FlexPDE software, based on the finite element method. The efficiency of the solution is analyzed in terms of reducing the vertical and horizontal components. Results are presented in the form of a dimensionless amplitude reduction factor. In each case being analyzed, a vibration mitigation effect in a three-story building was achieved.

  17. An Energy-Efficient and Scalable Deep Learning/Inference Processor With Tetra-Parallel MIMD Architecture for Big Data Applications.

    Science.gov (United States)

    Park, Seong-Wook; Park, Junyoung; Bong, Kyeongryeol; Shin, Dongjoo; Lee, Jinmook; Choi, Sungpill; Yoo, Hoi-Jun

    2015-12-01

    Deep Learning algorithm is widely used for various pattern recognition applications such as text recognition, object recognition and action recognition because of its best-in-class recognition accuracy compared to hand-crafted algorithm and shallow learning based algorithms. Long learning time caused by its complex structure, however, limits its usage only in high-cost servers or many-core GPU platforms so far. On the other hand, the demand on customized pattern recognition within personal devices will grow gradually as more deep learning applications will be developed. This paper presents a SoC implementation to enable deep learning applications to run with low cost platforms such as mobile or portable devices. Different from conventional works which have adopted massively-parallel architecture, this work adopts task-flexible architecture and exploits multiple parallelism to cover complex functions of convolutional deep belief network which is one of popular deep learning/inference algorithms. In this paper, we implement the most energy-efficient deep learning and inference processor for wearable system. The implemented 2.5 mm × 4.0 mm deep learning/inference processor is fabricated using 65 nm 8-metal CMOS technology for a battery-powered platform with real-time deep inference and deep learning operation. It consumes 185 mW average power, and 213.1 mW peak power at 200 MHz operating frequency and 1.2 V supply voltage. It achieves 411.3 GOPS peak performance and 1.93 TOPS/W energy efficiency, which is 2.07× higher than the state-of-the-art.

  18. Effect of grinding intensity and pelleting of the diet on indoor particulate matter concentrations and growth performance of weanling pigs.

    Science.gov (United States)

    Ulens, T; Demeyer, P; Ampe, B; Van Langenhove, H; Millet, S

    2015-02-01

    This study evaluated the effect of feed form and grinding intensity of the pig diet and the interaction between both on the particulate matter (PM) concentrations inside a pig nursery and the growth performances of weanling pigs. Four diets were compared: finely ground meal, coarsely ground meal, finely ground pellets, and coarsely ground pellets. Four weaning rounds with 144 pigs per weaning round, divided over 4 identical compartments, were monitored. Within each weaning round, each compartment was randomly assigned to 1 of 4 treatments. A hammer mill with a screen of 1.5 or 6 mm was used to grind the ingredients of the finely ground and coarsely ground feeds, respectively. Indoor concentrations of the following PM fractions were measured: PM that passes through a size-selective inlet with a 50 % efficiency cutoff at 10 (PM10) , 2.5 (PM2.5), or 1 (PM1) μm aerodynamic diameter, respectively (USEPA, 2004). Feeding pelleted diets instead of meal diets gave rise to higher PM10 (P Grinding intensity had an effect only on PM10 (P grinding intensity was found for any of the PM fractions. Interactions (P grinding intensity on ADFI and ADG were found. Grinding intensity had an effect only on the meal diets with higher ADFI for the coarsely ground meal. Pigs fed the finely ground meal had a lower (P grinding intensity. Pelleting the feed gave rise to a higher G:F. In conclusion, a contradiction between environmental concerns and performance results was found. Feeding pelleted diets to the piglets improved growth performance but also increased indoor PM concentrations.

  19. Adapting Wave-front Algorithms to Efficiently Utilize Systems with Deep Communication Hierarchies

    International Nuclear Information System (INIS)

    Kerbyson, Darren J.; Lang, Michael; Pakin, Scott

    2011-01-01

    Large-scale systems increasingly exhibit a differential between intra-chip and inter-chip communication performance especially in hybrid systems using accelerators. Processor cores on the same socket are able to communicate at lower latencies, and with higher bandwidths, than cores on different sockets either within the same node or between nodes. A key challenge is to efficiently use this communication hierarchy and hence optimize performance. We consider here the class of applications that contains wavefront processing. In these applications data can only be processed after their upstream neighbors have been processed. Similar dependencies result between processors in which communication is required to pass boundary data downstream and whose cost is typically impacted by the slowest communication channel in use. In this work we develop a novel hierarchical wave-front approach that reduces the use of slower communications in the hierarchy but at the cost of additional steps in the parallel computation and higher use of on-chip communications. This tradeoff is explored using a performance model. An implementation using the Reverse-acceleration programming model on the petascale Roadrunner system demonstrates a 27% performance improvement at full system-scale on a kernel application. The approach is generally applicable to large-scale multi-core and accelerated systems where a differential in system communication performance exists.

  20. New subsea X tree generation brings innovative features providing efficiency for ultra deep waters

    Energy Technology Data Exchange (ETDEWEB)

    Araujo, Gustavo Bellot de Almeida; Labes, Alan Zaragoza [FMC Technologies, Houston, TX (United States)

    2008-07-01

    The EVDT has been developed for global applications. Based upon the widely field proven 10 K Vertical Tree and 15 K HPHT Tree, the system has incorporated the latest technological advancements. The Tubing Hanger System and installation tooling are available up to a 7 inch bore for 10,000 psi applications and a 5 inch bore for 15,000 psi applications. The Tubing Hanger can be installed using a Tubing Head when flexibility for sequencing of events is required during offshore installations. Or it can simply land into the wellhead, eliminating the Tubing Head. This allows for a more efficient installation when completion and drilling operations are conducted without retrieving the Sub sea Blow Out Preventer (BOP) and Riser. The EVDT incorporates a retrievable Flow Module downstream of the wing valve that can be configured to project specific variances such as production, gas injection and water injection service. The Flow Module can also be configured to include Multi-Phase Flow Meters, sensors, and gauges. This allows an upgrade sub sea without having to pull and re-run the entire Tree system. These features allowed the system to hit the mark regarding what the industry needs today and also allowed to accommodate technologies that will arise in the years to come. (author)

  1. Strength and residual stress of Mg-PSZ after grinding

    NARCIS (Netherlands)

    van den Berg, P.H.J.; With, de G.

    1993-01-01

    The influence of grinding with two grinding wheels, differing mainly in diamond-grain size, on the properties of MgO-partially stabilized ZrO2 ceramics (Mg-PSZ) was examd. The residual stress, the amt. of monoclinic zirconia, and the strength of the material were detd. From these measurements, depth

  2. Occlusal Grinding Pattern during Sleep Bruxism and Temporomandibular Disorder

    Directory of Open Access Journals (Sweden)

    Yeni Wijaya

    2013-09-01

    Full Text Available Sleep Bruxism is a significant etiology of temporomandibular disorder (TMD and causes many dental or oral problems such as tooth wear or facet. There is no study analyzing the relationship between sleep bruxism and TMD. Objective: To investigate any relationship between occlusal grinding pattern during sleep bruxism and temporomandibular disorder. Methods: A cross-sectional study involving 30 sleep bruxism patients attended the Faculty Dentistry Universitas Indonesia Teaching Hospital (RSGMP FKG UI. Completion of 2 forms of ID-TMD index and questionnaire from American Academy of Sleep Medicine were done. BruxChecker was fabricated and used for two nights to record the occlusal grinding pattern. The occlusal grinding pattern was categorized into laterotrusive grinding (LG and mediotrusive side. Further divisons of LG were: incisor-canine (IC, incisor-caninepremolar (ICP and incisor-canine-premolar-molar (ICPM. Mediotrusive side was classified as mediotrusive contact (MC and mediotrusive grinding (MG. Results: It was found that occlusal grinding pattern in non-TMD subjects were IC+MC, in subjects with mild TMD were ICP+MG and in subjects with moderate TMD were ICP+MG and ICPM+MG. TMJ was more significantly affected by ICP and ICPM grinding pattern than that of IC. Conclusion: There was a significant relationship between occlusal grinding pattern during sleep bruxism and TMD.DOI: 10.14693/jdi.v20i2.149

  3. Ductile mode grinding of reaction-bonded silicon carbide mirrors.

    Science.gov (United States)

    Dong, Zhichao; Cheng, Haobo

    2017-09-10

    The demand for reaction-bonded silicon carbide (RB-SiC) mirrors has escalated recently with the rapid development of space optical remote sensors used in astronomy or Earth observation. However, RB-SiC is difficult to machine due to its high hardness. This study intends to perform ductile mode grinding to RB-SiC, which produces superior surface integrity and fewer subsurface damages, thus minimizing the workload of subsequent lapping and polishing. For this purpose, a modified theoretical model for grain depth of cut of grinding wheels is presented, which correlates various processing parameters and the material characteristics (i.e., elastic module) of a wheel's bonding matrix and workpiece. Ductile mode grinding can be achieved as the grain depth of cut of wheels decreases to be less than the critical cut depth of workpieces. The theoretical model gives a roadmap to optimize the grinding parameters for ductile mode grinding of RB-SiC and other ultra-hard brittle materials. Its feasibility was validated by experiments. With the optimized grinding parameters for RB-SiC, the ductile mode grinding produced highly specular surfaces (with roughness of ∼2.2-2.8  nm Ra), which means the material removal mechanism of RB-SiC is dominated by plastic deformation rather than brittle fracture. Contrast experiments were also conducted on fused silica, using the same grinding parameters; this produced only very rough surfaces, which further validated the feasibility of the proposed model.

  4. Assessment of Metallic Contaminants in Grinded Millet using ...

    African Journals Online (AJOL)

    OLUWASOGO

    Separate grinding discs were used for different millet forms, while the same quantity of millet ... have bad effects on human health (Normayo et al, 2010, Edem et al, 2012 .... grinding discs to have close contact due to the hardness of the millet.

  5. 7 CFR 58.726 - Cutting and grinding.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Cutting and grinding. 58.726 Section 58.726 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards... Procedures § 58.726 Cutting and grinding. The trimmed and cleaned cheese should be cut into sections of...

  6. Growth temperature dependence of Si doping efficiency and compensating deep level defect incorporation in Al0.7Ga0.3N

    International Nuclear Information System (INIS)

    Armstrong, Andrew M.; Moseley, Michael W.; Allerman, Andrew A.; Crawford, Mary H.; Wierer, Jonathan J.

    2015-01-01

    The growth temperature dependence of Si doping efficiency and deep level defect formation was investigated for n-type Al 0.7 Ga 0.3 N. It was observed that dopant compensation was greatly reduced with reduced growth temperature. Deep level optical spectroscopy and lighted capacitance-voltage were used to understand the role of acceptor-like deep level defects on doping efficiency. Deep level defects were observed at 2.34 eV, 3.56 eV, and 4.74 eV below the conduction band minimum. The latter two deep levels were identified as the major compensators because the reduction in their concentrations at reduced growth temperature correlated closely with the concomitant increase in free electron concentration. Possible mechanisms for the strong growth temperature dependence of deep level formation are considered, including thermodynamically driven compensating defect formation that can arise for a semiconductor with very large band gap energy, such as Al 0.7 Ga 0.3 N

  7. Heart-Rate Variability During Deep Sleep in World-Class Alpine Skiers: A Time-Efficient Alternative to Morning Supine Measurements.

    Science.gov (United States)

    Herzig, David; Testorelli, Moreno; Olstad, Daniela Schäfer; Erlacher, Daniel; Achermann, Peter; Eser, Prisca; Wilhelm, Matthias

    2017-05-01

    It is increasingly popular to use heart-rate variability (HRV) to tailor training for athletes. A time-efficient method is HRV assessment during deep sleep. To validate the selection of deep-sleep segments identified by RR intervals with simultaneous electroencephalography (EEG) recordings and to compare HRV parameters of these segments with those of standard morning supine measurements. In 11 world-class alpine skiers, RR intervals were monitored during 10 nights, and simultaneous EEGs were recorded during 2-4 nights. Deep sleep was determined from the HRV signal and verified by delta power from the EEG recordings. Four further segments were chosen for HRV determination, namely, a 4-h segment from midnight to 4 AM and three 5-min segments: 1 just before awakening, 1 after waking in supine position, and 1 in standing after orthostatic challenge. Training load was recorded every day. A total of 80 night and 68 morning measurements of 9 athletes were analyzed. Good correspondence between the phases selected by RR intervals vs those selected by EEG was found. Concerning root-mean-squared difference of successive RR intervals (RMSSD), a marker for parasympathetic activity, the best relationship with the morning supine measurement was found in deep sleep. HRV is a simple tool for approximating deep-sleep phases, and HRV measurement during deep sleep could provide a time-efficient alternative to HRV in supine position.

  8. Mandibular condylar morphology for bruxers with different grinding patterns.

    Science.gov (United States)

    Tao, Jianxiang; Wu, Junhua; Zhang, Xuying

    2016-07-01

    The purpose of this study was to investigate the mandibular condylar morphology for bruxers with different grinding patterns. Condylar sectional morphology and condylar position of 30 subjects were determined by two viewers using cone beam computed tomography (CBCT) image data sets. The grinding patterns during sleep bruxism (SB) were determined objectively using a Brux-checker device.Chi-square tests were used for statistical analysis for the condylar morphology type between different tooth grinding patterns. Spearman's rank correlation coefficient was used for correlation analysis between condylar position and the canine guidance area during SB. Theincidence of condylarmorphologicaldivergence from idealwas35%.There isa significant difference in distribution of condylar morphology type between the group grinding (GG) and GG combined with mediotrusive side grinding (MG) (p < 0.05). There was no significant correlation between condylar position and canine guidance area during bruxism. MG during SB is associated with condylar morphology that is considered not to be ideal.

  9. Performance of Metal Cutting on Endmills Manufactured by Cooling-Air and Minimum Quantity Lubrication Grinding

    Science.gov (United States)

    Inoue, Shigeru; Aoyama, Tojiro

    Grinding fluids have been commonly used during the grinding of tools for their cooling and lubricating effect since the hard, robust materials used for cutting tools are difficult to grind. Grinding fluids help prevent a drop in hardness due to burning of the cutting edge and keep chipping to an absolute minimum. However, there is a heightened awareness of the need to improve the work environment and protect the global environment. Thus, the present study is aimed at applying dry grinding, cooling-air grinding, cooling-air grinding with minimum quantity lubrication (MQL), and oil-based fluid grinding to manufacturing actual endmills (HSS-Co). Cutting tests were performed by a vertical machining center. The results indicated that the lowest surface inclination values and longest tool life were obtained by cooling-air grinding with MQL. Thus, cooling-air grinding with MQL has been demonstrated to be at least as effective as oil-based fluid grinding.

  10. Numerical Simulation of a Grinding Process for the Spatial Work-pieces: a Model of the Workpiece and Grinding Wheel

    Directory of Open Access Journals (Sweden)

    I. A. Kiselev

    2015-01-01

    Full Text Available The paper describes a spatial grinding dynamics mathematical model. This model includes a grinding wheel dynamics model, a work-piece dynamics model, and a numerical algorithm of geometric modeling as well. The geometric modeling algorithm is based on the Z-buffer method with author’s modifications. This algorithm allows us to simulate the formation of a new workpiece surface when removing material and as well as to determine the cutting layer thickness for each abrasive grain of the grinding wheel. The use of the surface cell bilinear approximation and the simultaneous use of multiple projection directions are the special features of the algorithm. These features improve modeling quality of machined surface. The grinding wheel model is represented as cutting micro-edges (grains set. Abrasive grains are randomly distributed on the wheel outer surface. Grains size, shape, wheel structure and graininess are taken into account. To determine the uncut chip thickness, which is cut off by each grain of the grinding wheel is used the algorithm, which finds intersection point of uncut work-piece surface with radial ray passing through the grain cutting edge. Grinding forces for each grain are defined based on the cutting layer thickness value using the phenomenological models described in the literature. Using transformations described in the article, grinding forces determined for each grain are reduced to the total grinding force, which acts on the tool and machined work-piece in the appropriate coordinate systems. Work-piece dynamics is modeled with the help of the finite element method using quadratic tetrahedral elements. The described model of spatial grinding dynamics makes it possible to evaluate the level of vibration and grinding forces, as well as the shape errors and surface quality of machined work-piece.

  11. Imaging-based enrichment criteria using deep learning algorithms for efficient clinical trials in mild cognitive impairment.

    Science.gov (United States)

    Ithapu, Vamsi K; Singh, Vikas; Okonkwo, Ozioma C; Chappell, Richard J; Dowling, N Maritza; Johnson, Sterling C

    2015-12-01

    The mild cognitive impairment (MCI) stage of Alzheimer's disease (AD) may be optimal for clinical trials to test potential treatments for preventing or delaying decline to dementia. However, MCI is heterogeneous in that not all cases progress to dementia within the time frame of a trial and some may not have underlying AD pathology. Identifying those MCIs who are most likely to decline during a trial and thus most likely to benefit from treatment will improve trial efficiency and power to detect treatment effects. To this end, using multimodal, imaging-derived, inclusion criteria may be especially beneficial. Here, we present a novel multimodal imaging marker that predicts future cognitive and neural decline from [F-18]fluorodeoxyglucose positron emission tomography (PET), amyloid florbetapir PET, and structural magnetic resonance imaging, based on a new deep learning algorithm (randomized denoising autoencoder marker, rDAm). Using ADNI2 MCI data, we show that using rDAm as a trial enrichment criterion reduces the required sample estimates by at least five times compared with the no-enrichment regime and leads to smaller trials with high statistical power, compared with existing methods. Copyright © 2015 The Alzheimer's Association. Published by Elsevier Inc. All rights reserved.

  12. Deep Eutectic Solvents as Efficient Media for the Extraction and Recovery of Cynaropicrin from Cynara cardunculus L. Leaves.

    Science.gov (United States)

    de Faria, Emanuelle L P; do Carmo, Rafael S; Cláudio, Ana Filipa M; Freire, Carmen S R; Freire, Mara G; Silvestre, Armando J D

    2017-10-30

    In recent years a high demand for natural ingredients with nutraceutical properties has been witnessed, for which the development of more environmentally-friendly and cost-efficient extraction solvents and methods play a primary role. In this perspective, in this work, the application of deep eutectic solvents (DES), composed of quaternary ammonium salts and organic acids, as alternative solvents for the extraction of cynaropicrin from Cynara cardunculus L. leaves was studied. After selecting the most promising DES, their aqueous solutions were investigated, allowing to obtain a maximum cynaropicrin extraction yield of 6.20 wt %, using 70 wt % of water. The sustainability of the extraction process was further optimized by carrying out several extraction cycles, reusing either the biomass or the aqueous solutions of DES. A maximum cynaropicrin extraction yield of 7.76 wt % by reusing the solvent, and of 8.96 wt % by reusing the biomass, have been obtained. Taking advantage of the cynaropicrin solubility limit in aqueous solutions, water was added as an anti-solvent, allowing to recover 73.6 wt % of the extracted cynaropicrin. This work demonstrates the potential of aqueous solutions of DES for the extraction of value-added compounds from biomass and the possible recovery of both the target compounds and solvents.

  13. Effect of grinding on photostimuable phosphors for x-ray screens

    International Nuclear Information System (INIS)

    Rao, R.B.

    1988-01-01

    Luminescence efficiency of a phosphor can be improved by minimizing the energy losses during excitation. The loss of excitation energy in the case of powdered samples is mainly due to scattering of incident radiation by the particles of phosphor. Thus, while considering the industrial applications of polycrystalline phosphors in lamps, screens, paints, etc., the effect of particle size on the light output has to be specially studied. It is very well established that the radiographic imaging with photostimuable (PS) phosphors has many advantages over conventional photographic film screens. In the new type of computer radiography, PS phosphors are to be used as memory materials for temporary storage of the x-ray image. Eu(2+) doped barium fluorohalide phosphors are most suitable for this purpose. The spatial resolution from the image plate can be improved to a certain extent with phosphors comprising fine particles. The fineness of the particles can be achieved by various means such as grinding, fast cooling after firing or incorporation of some flux materials during the firing processes. But the efficiency of the phosphor deteriorates with grinding. Fast cooling is a complicated process in the case of Eu(2+) doped phosphors. Incorporation of flux materials may change the characteristics of phosphor materials. In the present investigation, effect of grinding (ball milling) on particle size distribution, shape of the particles and luminescent properties of BaFCl phosphors have been studied

  14. Manipulating the Electronic Excited State Energies of Pyrimidine-Based Thermally Activated Delayed Fluorescence Emitters To Realize Efficient Deep-Blue Emission.

    Science.gov (United States)

    Komatsu, Ryutaro; Ohsawa, Tatsuya; Sasabe, Hisahiro; Nakao, Kohei; Hayasaka, Yuya; Kido, Junji

    2017-02-08

    The development of efficient and robust deep-blue emitters is one of the key issues in organic light-emitting devices (OLEDs) for environmentally friendly, large-area displays or general lighting. As a promising technology that realizes 100% conversion from electrons to photons, thermally activated delayed fluorescence (TADF) emitters have attracted considerable attention. However, only a handful of examples of deep-blue TADF emitters have been reported to date, and the emitters generally show large efficiency roll-off at practical luminance over several hundreds to thousands of cd m -2 , most likely because of the long delayed fluorescent lifetime (τ d ). To overcome this problem, we molecularly manipulated the electronic excited state energies of pyrimidine-based TADF emitters to realize deep-blue emission and reduced τ d . We then systematically investigated the relationships among the chemical structure, properties, and device performances. The resultant novel pyrimidine emitters, called Ac-XMHPMs (X = 1, 2, and 3), contain different numbers of bulky methyl substituents at acceptor moieties, increasing the excited singlet (E S ) and triplet state (E T ) energies. Among them, Ac-3MHPM, with a high E T of 2.95 eV, exhibited a high external quantum efficiency (η ext,max ) of 18% and an η ext of 10% at 100 cd m -2 with Commission Internationale de l'Eclairage chromaticity coordinates of (0.16, 0.15). These efficiencies are among the highest values to date for deep-blue TADF OLEDs. Our molecular design strategy provides fundamental guidance to design novel deep-blue TADF emitters.

  15. Fundamentals of grinding : surface conditions of ground WC-Co systems

    NARCIS (Netherlands)

    Hegeman, JBJW; De Hosson, JTM; Shulepov, SY; Lousberg, N; de With, G; Brebbia, CA; Kenny, JM

    1999-01-01

    This paper concentrates on the fundamentals of grinding of inorganic materials. A statistical grinding model was developed based on the topography of the grinding wheel. The results of the model are compared with the results of grinding experiments on WC-Co hardmetals. The calculated profiles and

  16. Highly efficient and simplified phosphorescence white organic light-emitting diodes based on synthesized deep-blue host and orange emitter

    Energy Technology Data Exchange (ETDEWEB)

    Koo, Ja Ryong; Lee, Seok Jae; Hyung, Gun Woo; Kim, Bo Young; Lee, Dong Hyung [Department of Information Display, Hongik University, Seoul 121-791 (Korea, Republic of); Kim, Woo Young [Department of Green Energy and Semiconductor Engineering, Hoseo University, Asan 336-795 (Korea, Republic of); Lee, Kum Hee [Department of Chemistry, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); Yoon, Seung Soo, E-mail: ssyoon@skku.edu [Department of Chemistry, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); Kim, Young Kwan, E-mail: kimyk@hongik.ac.kr [Department of Information Display, Hongik University, Seoul 121-791 (Korea, Republic of)

    2013-10-01

    The authors have demonstrated a highly efficient and stable phosphorescent white organic light-emitting diode (WOLED), which has been achieved by doping only one orange phosphorescent emitter, Bis(5-benzoyl-2-(4-fluorophenyl)pyridinato-C,N)iridium(III) acetylacetonate into an appropriate deep blue phosphorescent host, 4,4'-bis(4-(triphenylsilyl)phenyl)-1,1'-binaphthyl as an emitting layer (EML). The WOLED has been achieved by effective confinement of triplet excitons to emit a warm white color. The optimized WOLED, with a simple structure as a hole transporting layer-EML-electron transporting layer, showed a maximum luminous efficiency of 22.38 cd/A, a maximum power efficiency of 12.01 lm/W, a maximum external quantum efficiency of 7.32%, and CIEx,y coordinates of (0.38,0.42) at 500 cd/m{sup 2}, respectively. - Highlights: • Highly efficient phosphorescent white organic light-emitting diode (WOLED) • Single emitting layer consists of synthesized deep blue host and orange emitter • The WOLED with high EL efficiencies due to efficient triplet exciton confinement.

  17. Experimental Study of Tool Wear and Grinding Forces During BK-7 Glass Micro-grinding with Modified PCD Tool

    Science.gov (United States)

    Pratap, A.; Sahoo, P.; Patra, K.; Dyakonov, A. A.

    2017-09-01

    This study focuses on the improvement in grinding performance of BK-7 glass using polycrystalline diamond micro-tool. Micro-tools are modified using wire EDM and performance of modified tools is compared with that of as received tool. Tool wear of different types of tools are observed. To quantify the tool wear, a method based on weight loss of tool is introduced in this study. Modified tools significantly reduce tool wear in comparison to the normal tool. Grinding forces increase with machining time due to tool wear. However, modified tools produce lesser forces thus can improve life of the PCD micro-grinding tool.

  18. Technics study on high accuracy crush dressing and sharpening of diamond grinding wheel

    Science.gov (United States)

    Jia, Yunhai; Lu, Xuejun; Li, Jiangang; Zhu, Lixin; Song, Yingjie

    2011-05-01

    Mechanical grinding of artificial diamond grinding wheel was traditional wheel dressing process. The rotate speed and infeed depth of tool wheel were main technics parameters. The suitable technics parameters of metals-bonded diamond grinding wheel and resin-bonded diamond grinding wheel high accuracy crush dressing were obtained by a mount of experiment in super-hard material wheel dressing grind machine and by analysis of grinding force. In the same time, the effect of machine sharpening and sprinkle granule sharpening was contrasted. These analyses and lots of experiments had extent instruction significance to artificial diamond grinding wheel accuracy crush dressing.

  19. Innovative grinding wheel design for cost-effective machining of advanced ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Licht, R.H.; Kuo, P.; Liu, S.; Murphy, D.; Picone, J.W.; Ramanath, S.

    2000-05-01

    This Final Report covers the Phase II Innovative Grinding Wheel (IGW) program in which Norton Company successfully developed a novel grinding wheel for cost-effective cylindrical grinding of advanced ceramics. In 1995, Norton Company successfully completed the 16-month Phase I technical effort to define requirements, design, develop, and evaluate a next-generation grinding wheel for cost-effective cylindrical grinding of advanced ceramics using small prototype wheels. The Phase II program was initiated to scale-up the new superabrasive wheel specification to larger diameters, 305-mm to 406-mm, required for most production grinding of cylindrical ceramic parts, and to perform in-house and independent validation grinding tests.

  20. Grinding Method and Error Analysis of Eccentric Shaft Parts

    Science.gov (United States)

    Wang, Zhiming; Han, Qiushi; Li, Qiguang; Peng, Baoying; Li, Weihua

    2017-12-01

    RV reducer and various mechanical transmission parts are widely used in eccentric shaft parts, The demand of precision grinding technology for eccentric shaft parts now, In this paper, the model of X-C linkage relation of eccentric shaft grinding is studied; By inversion method, the contour curve of the wheel envelope is deduced, and the distance from the center of eccentric circle is constant. The simulation software of eccentric shaft grinding is developed, the correctness of the model is proved, the influence of the X-axis feed error, the C-axis feed error and the wheel radius error on the grinding process is analyzed, and the corresponding error calculation model is proposed. The simulation analysis is carried out to provide the basis for the contour error compensation.

  1. Grinding of Inconel 713 superalloy for gas turbines

    Czech Academy of Sciences Publication Activity Database

    Čapek, J.; Kyncl, J.; Kolařík, K.; Beránek, L.; Pitrmuc, Z.; Medřický, Jan; Pala, Z.

    2016-01-01

    Roč. 16, č. 1 (2016), s. 14-15 ISSN 1213-2489 Institutional support: RVO:61389021 Keywords : Casting defects * Gas turbine * Grinding * Nickel superalloy * Residual stresses Subject RIV: JJ - Other Materials

  2. Gemstone Grinding Process Improvement by using Impedance Force Control

    Directory of Open Access Journals (Sweden)

    Hamprommarat Chumpol

    2015-01-01

    Full Text Available Chula Automatic Faceting Machine has been developed by The Advance Manufacturing Research Lab, Chulalongkorn University to support Thailand Gems-Industry. The machine has high precision motion control by using position and force control. A contact stiffness model is used to estimate grinding force. Although polished gems from the Faceting Machine have uniform size and acceptable shape, the force of the grinding and polishing process cannot be maintain constant and has some fluctuation due to indirect force control. Therefor this research work propose a new controller for this process based on an impedance direct force control to improve the gemstone grinding performance during polishing process. The grinding force can be measured through motor current. The results show that the polished gems by using impedance direct force control can maintain uniform size as well as good shape and high quality surface.

  3. short communication simple grinding-induced reactions of 2

    African Journals Online (AJOL)

    Preferred Customer

    SIMPLE GRINDING-INDUCED REACTIONS OF 2-AMINOBENZYL ... As part of our broad interest in the chemistry of heterocyclic compounds [10, 11], the .... study grant) and the University of Botswana (THT study grant) for financial support, Dr.

  4. Comparison of Wet and Dry Grinding in Electromagnetic Mill

    Directory of Open Access Journals (Sweden)

    Szymon Ogonowski

    2018-03-01

    Full Text Available Comparison of dry and wet grinding process in an electromagnetic mill is presented in this paper. The research was conducted in a batch copper ore grinding. Batch mode allows for precise parametrization and constant repetitive conditions of the experiments. The following key aspects were tested: processing time, feed size, size of the grinding media, mass of the material and graining media, and density of the pulp. The particles size distribution of the product samples was analyzed in the laboratory after each experiment. The paper discusses the experimental results as well as the concept of dry and wet grinding and classification circuits for the electromagnetic mill. The main points of the discussion are the size reduction effectiveness and power consumption of the entire system.

  5. Grinding as a method of meat texture evaluation.

    Science.gov (United States)

    Kenmegne Kamdem, A T; Hardy, J

    1995-01-01

    An electric grinder equipped with a torque/speed sensor was used to evaluate maximum grinding torque (T(max)) and total energy (TE) necessary to grind 150 g of uncooked meat. Texture profile analysis (TPA), relaxation and cutting tests were carried out and sample compositions were also determined. The degree of dependence between grinding, TPA, relaxation, cutting parameters and sample composition was checked. Results showed that grinding parameters (T(max) and TE) correlated better with TPA, relaxation and cutting parameters than with composition. In particular correlation coefficient of -0·92, -0·92 and 0·97 were obtained, respectively, between T(max) and relaxation percentage (%R), T(max) and destructuring coefficient at 25% conmpression (De(25)) and between T(max) and maximum cutting force (F(c)).

  6. ANFIS Modeling of the Surface Roughness in Grinding Process

    OpenAIRE

    H. Baseri; G. Alinejad

    2011-01-01

    The objective of this study is to design an adaptive neuro-fuzzy inference system (ANFIS) for estimation of surface roughness in grinding process. The Used data have been generated from experimental observations when the wheel has been dressed using a rotary diamond disc dresser. The input parameters of model are dressing speed ratio, dressing depth and dresser cross-feed rate and output parameter is surface roughness. In the experimental procedure the grinding conditions...

  7. Effect of electromagnetic radiation on the kinetics of grinding a mineral

    International Nuclear Information System (INIS)

    Lopez M, A.; Delgadillo G, J. A.; Vega C, H. R.

    2015-10-01

    In this study the effect of kinetic grinding of a mineral was investigated when is pre treated with ionizing electromagnetic radiation. This radiation is with 15 MeV photons produced by a Linac for Radiotherapy. The results for the irradiated sample with respect to the non-irradiated indicate that there were changes in the structure of the minerals in the sample under study. Changes were observed through scanning electron microscopy and X-ray diffraction, combined with the refinement of the diffraction profiles by the Rietveld method using the software Maud Program. The grinding kinetics shows a constant distribution of slightly greater size through time used for the irradiated sample. A reduction of 11.2% of the Bond (Wi) work index was reached, going from 10.91 to 9.69 kw h/t for the irradiated sample. This parameter represents the fracture toughness of a mineral. The results indicate greater efficiency of energy applied to the grinding of the irradiated sample with respect to the non-irradiated. (Author)

  8. The New Grinding Process for Camshaft in Locomotive Engine%机车发动机用凸轮轴磨削新工艺

    Institute of Scientific and Technical Information of China (English)

    王歆令; 李静; 沈南燕; 何永义

    2013-01-01

    According to the geometric characteristics of camshaft in locomotive engine,this paper analyzed the difficulties and disadvantages of traditional grinding process that the concave arc of cam is machined by single type grinding wheel,thus a new grinding process that camshaft is machined by large size and small size grinding wheels was proposed.To avoid the concave arc when machining by large size grinding wheel and guarantee no vibration and impact,the reconstruction of concave arc and optimization of grinding carriage velocity were completed.The experimental results of grinding show that grinding accuracy and efficiency were improved by this new process,which demonstrates its feasibility.%针对机车发动机用凸轮轴几何特征,分析了传统磨削工艺中磨削全程使用一种型号的砂轮对凸轮轮廓的凹弧段进行加工的难点和弊端,提出了大小砂轮配合磨削凸轮轴的新工艺.实施过程中为了保证大砂轮避开凸轮轮廓的凹孤段且加工过程无振动冲击,完成了凸轮凹孤段轮廓重构以及砂轮架速度优化.磨削实验结果表明,采用该新工艺能提高凸轮轴磨削的精度和效率,具有很高的可行性.

  9. Precision Surface Grinding of Silicon Carbide

    Directory of Open Access Journals (Sweden)

    Mohamed Konneh

    2016-12-01

    Full Text Available Silicon carbide (SiC is well known for its excellent material properties, high durability, high wear resistance, light weight and extreme hardness. Among the engineering applications of this material, it is an excellent candidate for optic mirrors used in an Airbone Laser (ABL device. However, the low fracture toughness and extreme brittleness characteristics of SiC are predominant factors for its poor machinability. This paper presents surface grinding of SiC using diamond cup wheels to assess the performance of diamond grits with respect to the roughness produced on the machined surfaces and also the morphology of the ground work-piece. Resin bonded diamond cup wheels of grit sizes 46 µm, 76 µm and 107 µm; depth of cut of 10 µm, 20 µm and 30 µm; and feed rate of 2 mm/min, 12 mm/min and 22 mm/min were used during this machining investigation. It has been observed that the 76 grit performs better in terms of low surface roughness value and morphology.

  10. Exploration on Wire Discharge Machining Added Powder for Metal-Based Diamond Grinding Wheel on Wire EDM Dressing and Truing of Grinding Tungsten Carbide Material

    Science.gov (United States)

    Chow, H. M.; Yang, L. D.; Lin, Y. C.; Lin, C. L.

    2017-12-01

    In this paper, the effects of material removal rate and abrasive grain protrusion on the metal-based diamond grinding wheel were studied to find the optimal parameters for adding powder and wire discharge. In addition, this kind of electric discharge method to add powder on the metal-based diamond grinding wheel on line after dressing and truing will be applied on tungsten carbide to study the grinding material removal rate, grinding wheel wear, surface roughness, and surface micro-hardness.

  11. Highly Efficient Solution-Processed Deep-Red Organic Light-Emitting Diodes Based on an Exciplex Host Composed of a Hole Transporter and a Bipolar Host.

    Science.gov (United States)

    Huang, Manli; Jiang, Bei; Xie, Guohua; Yang, Chuluo

    2017-10-19

    With the aim to achieve highly efficient deep-red emission, we introduced an exciplex forming cohost, 4,4',4″-tris(3-methylphenylphenylamino)triphenylamine (m-MTDATA): 2,5-bis(2-(9H-carbazol-9-yl)phenyl)-1,3,4-oxadiazole (o-CzOXD) (1:1). Due to the efficient triplet up-conversion processes upon the exciplex forming cohost, excellent performances of the devices were achieved with deep-red emission. Using the heteroleptic iridium complexes as the guest dopants, the solution-processed deep-red phosphorescent organic light-emitting diodes (PhOLEDs) with the iridium(III) bis(6-(4-(tert-butyl)phenyl)phenanthridine)acetylacetonate [(TP-BQ) 2 Ir(acac)]-based phosphorescent emitter exhibited an electroluminescent peak at 656 nm and a maximum external quantum efficiency (EQE) of 11.9%, which is 6.6 times that of the device based on the guest emitter doped in the polymer-based cohost. The unique exciplex with a typical hole transporter and a bipolar material is ideal and universal for hosting the red PhOLEDs and tremendously improves the device performances.

  12. Quenching simulation of steel grinding balls

    Directory of Open Access Journals (Sweden)

    Zapata-Hernández, Oscar

    2015-09-01

    Full Text Available The phase transformations of high carbon steel during quenching and equalizing were modelled using commercial computer packages based on the finite element method and the kinetic transformation of steel. The model was used to predict the temperature and microstructural changes taking place within balls of two different sizes that are used for grinding mineral ores. A good correlation between the temperatures measured by inserted thermocouples and those predicted by the model was obtained after modifying the thermal conductivity of the steel within the temperature domain at which mixed phases are present. The phase transformations predicted were confirmed by metallographic analyses.Las transformaciones de fase en aceros de alto carbono durante su temple y un posterior periodo de estabilización fueron modelizadas por medio del uso de paquetes computacionales basados en el método del elemento finito y de la transformación cinética de los aceros. El modelo se usó para predecir los cambios de temperatura y microestructura que se presentan en bolas de dos diferentes tamaños empleadas en estaciones de molienda de minerales. Se encontró una buena correlación entre las temperaturas medidas mediante la inserción de termopares y aquellas predichas por el modelo una vez que se modificó la conductividad térmica del acero en el intervalo mixto de fases. La predicción de las transformaciones de fase se confirmó a través del análisis metalográfico.

  13. Determining the direction of tooth grinding: an in vitro study.

    Science.gov (United States)

    ten Berge, F; te Poel, J; Ranjitkar, S; Kaidonis, J A; Lobbezoo, F; Hughes, T E; Townsend, G C

    2012-08-01

    The analysis of microwear patterns, including scratch types and widths, has enabled reconstruction of the dietary habits and lifestyles of prehistoric and modern humans. The aim of this in vitro study was to determine whether an assessment of microwear features of experimental scratches placed on enamel, perpendicularly to the direction of grinding, could predict the grinding direction. Experimental scratches were placed using a scalpel blade on standardised wear facets that had been prepared by wearing opposing enamel surfaces in an electromechanical tooth wear machine. These control 'baseline' facets (with unworn experimental scratches) were subjected to 50 wear cycles, so that differential microwear could be observed on the leading and trailing edges of the 'final' facets. In Group 1 (n=28), the 'footprint' microwear patterns corresponding to the known grinding direction of specimens in the tooth wear machine were identified. Then, they were used to predict the direction of tooth grinding blindly in the same sample after a 2-week intermission period. To avoid overfitting the predictive model, its sensitivity was also cross-validated in a new sample (Group 2, n=14). A crescent-shaped characteristic observed in most experimental scratches matched the grinding direction on all occasions. The best predictor of the direction of grinding was a combined assessment of the leading edge microwear pattern and the crescent characteristic (82.1% in Group 1 and 92.9% in Group 2). In conclusion, a simple scratch test can determine the direction of tooth grinding with high reliability, although further improvement in sensitivity is desirable. © 2012 Blackwell Publishing Ltd.

  14. Fatigue Tests on Welded Joints Improved by Grinding

    DEFF Research Database (Denmark)

    Agerskov, Henning; Bjørnbak-Hansen, Jørgen; Olesen, John Forbes

    The present project is a part of an investigation on the fatigue life of the welded structure of large two-stroke diesel engines. Of special interest has been a study of the improvement in fatigue life, due to grinding of the weld toes. The test series carried through showed a significant increase...... without grinding to approx. 6.4 for the test series with grinding. In one of the test series (No. 7), the crack initiation in most tests moved from the weld toe to the non-ground surface between the ground areas at the weld toes, due to the grinding....... in fatigue life due to the grinding, ranging from a factor of approx. 2.8 to infinity, depending on the load level. With the limited number of tests carried out, S-N lines have not been determined. However, the results obtained indicate a change in slope of the S-N line from approx. 3.0 for the test series...

  15. Industrial versus Laboratory Clinker Processing Using Grinding Aids (Scale Effect

    Directory of Open Access Journals (Sweden)

    Joseph Jean Assaad

    2015-01-01

    Full Text Available The evaluation of grinding aid (GA effect on clinker processing in laboratory grinding mills is relatively simple. Yet, the results obtained cannot be directly transposed to industrial mills, given the fundamentally different operational modes and grinding parameters. This paper seeks to evaluate the scale effect by comparing the results obtained from a closed-circuit tube mill operating at 90 ton/hr to those determined using a 50-liter laboratory mill. Tests results have shown that the decrease in specific energy consumption (Ec due to glycol or amine-based GA can be evaluated under laboratory conditions. However, such tests underestimate the actual performance that could be achieved in real-scale mills; the Ec reduction due to GA is around twofold higher when grinding is performed in real-scale mill. Compared to industrial tests, the cement particle size distribution curves widened and shifted towards higher diameters when grinding was performed under laboratory conditions, particularly with GA additions. This led to remarkable changes in water demand, setting time, and 1- and 28-day compressive strengths.

  16. TRISO-coated spent fuel processing using a Grind-Leach head-end

    International Nuclear Information System (INIS)

    Spencer, Barry B.; Del Cul, Guillermo D.; Mattus, Catherine H.; Collins, Emory D.

    2005-01-01

    Processing of TRISO-coated HTGR fuels with the grind-leach process requires that the fuel be finely pulverized for efficient and effective acid dissolution of the fuel components. Mechanical size reduction of the fuel is being investigated with jet mill technology as the final milling step. Laboratory experiments were performed with surrogates of crushed fuel compacts that indicate that milling to very small particle sizes is feasible. The size distribution of the milled product is sensitive to the solids feed rate, and the distribution may be bimodal which could support an effective solid-solid separation. (author)

  17. Deep blue exciplex organic light-emitting diodes with enhanced efficiency; P-type or E-type triplet conversion to singlet excitons?

    Science.gov (United States)

    Jankus, Vygintas; Chiang, Chien-Jung; Dias, Fernando; Monkman, Andrew P

    2013-03-13

    Simple trilayer, deep blue, fluorescent exciplex organic light-emitting diodes (OLEDs) are reported. These OLEDs emit from an exciplex state formed between the highest occupied molecular orbital (HOMO) of N,N'-bis(1-naphthyl)N,N'-diphenyl-1,1'-biphenyl-4,4'-diamine (NPB) and lowest unoccupied molecular orbital (LUMO) of 1,3,5-tri(1-phenyl-1H-benzo[d]imidazol-2-yl)phenyl (TPBi) and the NPB singlet manifold, yielding 2.7% external quantum efficiency at 450 nm. It is shown that the majority of the delayed emission in electroluminescence arises from P-type triplet fusion at NPB sites not E-type reverse intersystem crossing because of the presence of the NPB triplet state acting as a deep trap. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Grinding, Machining Morphological Studies on C/SiC Composites

    Science.gov (United States)

    Xiao, Chun-fang; Han, Bing

    2018-05-01

    C/SiC composite is a typical material difficult to machine. It is hard and brittle. In machining, the cutting force is large, the material removal rate is low, the edge is prone to collapse, and the tool wear is serious. In this paper, the grinding of C/Si composites material along the direction of fiber distribution is studied respectively. The surface microstructure and mechanical properties of C/SiC composites processed by ultrasonic machining were evaluated. The change of surface quality with the change of processing parameters has also been studied. By comparing the performances of conventional grinding and ultrasonic grinding, the surface roughness and functional characteristics of the material can be improved by optimizing the processing parameters.

  19. Evaluation of ball and roller bearings restored by grinding

    Science.gov (United States)

    Parker, R. J.; Zaretsky, E. V.; Chen, S. M.

    1976-01-01

    A joint program was undertaken to restore by grinding those rolling-element bearings which are currently being discarded at aircraft engine and transmission overhaul. Three bearing types were selected from the UH-1 helicopter engine (T-53) and transmission for the pilot program. Groups of each of these bearings were visually and dimensionally inspected for suitability for restoration. A total of 250 bearings were restored by grinding. Of this number, 30 bearings from each type were endurance tested to a TBO of 1600 hours. No bearing failures occurred related to the restoration by grinding process. The two bearing failures which occurred were due to defective rolling elements and were typical of those which may occur in new bearings. The restorable component yield to the three groups was in excess of 90 percent.

  20. High-speed, low-damage grinding of advanced ceramics Phase 1. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Kovach, J.A. [Eaton Corp., Willoughby Hills, OH (United States). Mfg. Technologies Center; Malkin, S. [Univ. of Massachusetts (United States)

    1995-03-01

    In manufacture of structural ceramic components, grinding costs can comprise up to 80% of the entire manufacturing cost. Most of these costs arise from the conventional multi-step grinding process with numerous grinding wheels and additional capital equipment, perishable dressing tools, and labor. In an attempt to reduce structural ceramic grinding costs, a feasibility investigation was undertaken to develop a single step, roughing-finishing process suitable for producing high-quality silicon nitride ceramic parts at high material removal rates at lower cost than traditional, multi-stage grinding. This feasibility study employed combined use of laboratory grinding tests, mathematical grinding models, and characterization of resultant material surface condition. More specifically, this Phase 1 final report provides a technical overview of High-Speed, Low-Damage (HSLD) ceramic grinding and the conditions necessary to achieve the small grain depths of cut necessary for low damage grinding while operating at relatively high material removal rates. Particular issues addressed include determining effects of wheel speed and material removal rate on resulting mode of material removal (ductile or brittle fracture), limiting grinding forces, calculation of approximate grinding zone temperatures developed during HSLD grinding, and developing the experimental systems necessary for determining HSLD grinding energy partition relationships. In addition, practical considerations for production utilization of the HSLD process are also discussed.

  1. Diamond grinding wheels production study with the use of the finite element method.

    Science.gov (United States)

    Kundrák, J; Fedorovich, V; Markopoulos, A P; Pyzhov, I; Kryukova, N

    2016-11-01

    Research results on 3D modeling of the diamond grain and its bearing layer when sintering diamond grinding wheels are provided in this paper. The influence of the main characteristics of the wheel materials and the wheel production process, namely the quantity of metallic phase within diamond grain, coefficient of thermal expansion of the metallic phase, the modulus of elasticity of bond material and sintering temperature, on the internal stresses arising in grains is investigated. The results indicate that the stresses in the grains are higher in the areas around the metallic phase. Additionally, sintering temperature has the greatest impact on the stresses of the grain-metallic phase-bond system regardless of the type of the bond. Furthermore, by employing factorial design for the carried out finite element model, a mathematical model that reflects the impact of these factors on the deflected mode of the diamond grain-metallic phase-bond material system is obtained. The results of the analysis allow for the identification of optimal conditions for the efficient production of improved diamond grinding wheels. More specifically, the smallest stresses are observed when using the metal bond with modulus of elasticity 204 GPa, the quantity of metallic phase in diamond grain of not higher than 7% and coefficient of thermal expansion of 1.32 × 10 -5  1/K or lower. The results obtained from the proposed 3D model can lead to the increase in the diamond grains utilization and improve the overall efficiency of diamond grinding.

  2. Dry grinding of talc in a stirred ball mill

    Directory of Open Access Journals (Sweden)

    Cayirli Serkan

    2016-01-01

    Full Text Available The aim of this work was to investigate micro fine size dry grindability of talc in a stirred ball mill. The effects of various parameters such as grinding time, stirrer speed, powder filling ratio and ball filling ratio were investigated. Alumina balls were used as grinding media. Experiments were carried out using the 24 full factorial design. The main and interaction effects were evaluated using the Yates method. Test results were evaluated on the basis of product size and surface area.

  3. Analysis of cement superplasticizers and grinding aids a literature survey

    International Nuclear Information System (INIS)

    Ervanne, H.; Hakanen, M.

    2007-04-01

    This literature survey reviews the methods for analysis of cement plasticizers and organic grounding aids in cement solutions in preparation of grouts/concrete and methods for determination of plasticizers and grinding aids in groundwater conditions. The survey focuses on three different types of superplasticizers: sulphonated naphthalene condensates, sulphonated melamine condensates and polycarboxylates. There are various organic grinding aids, such as alkanolamines, glycols or phenolic compounds, used in the cement industry. This review is concerned with the following compounds: triethylenetetramine, tetraethylenepentamine, diethanolamine, triethanolamine, triisopropanolamine, ethyleneglycol, diethyleneglycol, aminoethylethanolamine, hydroxyethyl diethylenetriamine and phenol. (orig.)

  4. Modeling and simulation for fewer-axis grinding of complex surface

    Science.gov (United States)

    Li, Zhengjian; Peng, Xiaoqiang; Song, Ci

    2017-10-01

    As the basis of fewer-axis grinding of complex surface, the grinding mathematical model is of great importance. A mathematical model of the grinding wheel was established, and then coordinate and normal vector of the wheel profile could be calculated. Through normal vector matching at the cutter contact point and the coordinate system transformation, the grinding mathematical model was established to work out the coordinate of the cutter location point. Based on the model, interference analysis was simulated to find out the right position and posture of workpiece for grinding. Then positioning errors of the workpiece including the translation positioning error and the rotation positioning error were analyzed respectively, and the main locating datum was obtained. According to the analysis results, the grinding tool path was planned and generated to grind the complex surface, and good form accuracy was obtained. The grinding mathematical model is simple, feasible and can be widely applied.

  5. Effect of disintegration wave grinding on fractional protein and amino acid composition of chickpea

    Directory of Open Access Journals (Sweden)

    G. O. Magomedov

    2013-01-01

    Full Text Available The study of fractional changes and amino acid composition of proteins in the application of chickpea disintegration wave grinding. Comparative analysis of six varieties of chickpea before and after grinding.

  6. Effect of disintegration wave grinding on fractional protein and amino acid composition of chickpea

    OpenAIRE

    G. O. Magomedov; M. K. Sadigova; S. I. Lukina; V. Y. Kustov

    2013-01-01

    The study of fractional changes and amino acid composition of proteins in the application of chickpea disintegration wave grinding. Comparative analysis of six varieties of chickpea before and after grinding.

  7. High-efficiency, deep-junction, epitaxial InP solar cells on (100) and (111)B InP substrates

    Science.gov (United States)

    Venkatasubramanian, R.; Timmons, M. L.; Hutchby, J. A.; Walters, Robert J.; Summers, Geoffrey P.

    1994-01-01

    We report on the development and performance of deep-junction (approximately 0.25 micron), graded-emitter-doped, n(sup +)-p InP solar cells grown by metallorganic chemical vapor deposition (MOCVD). A novel, diffusion-transport process for obtaining lightly-doped p-type base regions of the solar cell is described. The I-V data and external quantum-efficiency response of these cells are presented. The best active-area AMO efficiency for these deep-junction cells on (100)-oriented InP substrates is 16.8 percent, with a J(sub SC) of 31.8 mA/sq cm, a V(sub OC) of 0.843 V, and a fill-factor of 0.85. By comparison, the best cell efficiency on the (111)B-oriented InP substrates was 15.0 percent. These efficiency values for deep-junction cells are encouraging and compare favorably with performance of thin-emitter (0.03 micron) epitaxial cells as well as that of deep-emitter diffused cells. The cell performance and breakdown voltage characteristics of a batch of 20 cells on each of the orientations are presented, indicating the superior breakdown voltage properties and other characteristics of InP cells on the (111)B orientation. Spectral response, dark I-V data, and photoluminescence (PL) measurements on the InP cells are presented with an analysis on the variation in J(sub SC) and V(sub OC) of the cells. It is observed, under open-circuit conditions, that lower-V(sub OC) cells exhibit higher band-edge PL intensity for both the (100) and (111)B orientations. This anomalous behavior suggests that radiative recombination in the heavily-doped n(sup +)-InP emitter may be detrimental to achieving higher V(sub OC) in n(sup +)-p InP solar cells.

  8. Grinding tool for use in a fuel assembly repair and reconstitution system

    International Nuclear Information System (INIS)

    Tolino, R.W.

    1988-01-01

    A remotely operable grinding apparatus particularly adapted for abrasively removing a portion of a structure underwater is described comprising a baseplate, a motor means having an output shaft, a grinding head operatively connected to the output shaft, a housing for isolating the motor means from ambient water, guide means slidably connecting the housing to the baseplate for guiding the grinding head to a selected portion of the structure, and means for selectively moving the grinding head against the portion of the structure

  9. Robustness of a cross contamination model describing transfer of pathogens during grinding of meat

    DEFF Research Database (Denmark)

    Møller, Cleide Oliveira de Almeida; Sant’Ana, A. S.; Hansen, Solvej Katrine Holm

    2016-01-01

    This study aimed to evaluate a cross contamination model for its capability of describing transfer of Salmonella spp. and L. monocytogenes during grinding of varying sizes and numbers of pieces of meats in two grinder systems. Data from 19 trials were collected. Three evaluation approaches were a...... that grinding was influenced by sharpness of grinder knife, specific grinder and grinding temperature....

  10. 30 CFR 56.15014 - Eye protection when operating grinding wheels.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Eye protection when operating grinding wheels... MINES Personal Protection § 56.15014 Eye protection when operating grinding wheels. Face shields or goggles in good condition shall be worn when operating a grinding wheel. [53 FR 32526, Aug. 25, 1988] ...

  11. 30 CFR 57.15014 - Eye protection when operating grinding wheels.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Eye protection when operating grinding wheels. 57.15014 Section 57.15014 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF... grinding wheels. Face shields or goggles in good condition shall be worn when operating a grinding wheel...

  12. Deep Echo State Network (DeepESN): A Brief Survey

    OpenAIRE

    Gallicchio, Claudio; Micheli, Alessio

    2017-01-01

    The study of deep recurrent neural networks (RNNs) and, in particular, of deep Reservoir Computing (RC) is gaining an increasing research attention in the neural networks community. The recently introduced deep Echo State Network (deepESN) model opened the way to an extremely efficient approach for designing deep neural networks for temporal data. At the same time, the study of deepESNs allowed to shed light on the intrinsic properties of state dynamics developed by hierarchical compositions ...

  13. The Graduate Grind: A Critical Look at Graduate Education

    Directory of Open Access Journals (Sweden)

    Michelle K. McGinn

    2010-05-01

    Full Text Available Abandonment, abuse, anxiety, betrayal, bitterness, breaking point, burnout, collapse, danger, death, desperation, discouragement, divorce, exhaustion, frustration, grind, hardships, hazing, hurdles, ignorance, impossible dream, isolation, killing the spirit, leaving, loneliness, murder, neglect, peril, ridicule, ritual, self-protection, sexual harassment, shock, snobbery, strain, strangulation, stress, suffering, suicide, survival of the fittest, trauma, and violence.

  14. Photoacoustic study of nanocrystalline silicon produced by mechanical grinding

    Energy Technology Data Exchange (ETDEWEB)

    Poffo, C.M. [Departamento de Engenharia Mecanica, Universidade Federal de Santa Catarina, Campus Universitario Trindade, C.P. 476, 88040-900 Florianopolis, Santa Catarina (Brazil); Lima, J.C. de, E-mail: fsc1jcd@fisica.ufsc.b [Departamento de Fisica, Universidade Federal de Santa Catarina, Campus Trindade, C.P. 476, 88040-900 Florianopolis, Santa Catarina (Brazil); Souza, S.M.; Triches, D.M. [Departamento de Engenharia Mecanica, Universidade Federal de Santa Catarina, Campus Universitario Trindade, C.P. 476, 88040-900 Florianopolis, Santa Catarina (Brazil); Grandi, T.A. [Departamento de Fisica, Universidade Federal de Santa Catarina, Campus Trindade, C.P. 476, 88040-900 Florianopolis, Santa Catarina (Brazil); Biasi, R.S. de [Secao de Engenharia Mecanica e de Materiais, Instituto Militar de Engenharia, 22290-270 Rio de Janeiro, RJ (Brazil)

    2011-04-01

    Mechanical grinding (MG) was used to produce nanocrystalline silicon and its thermal and transport properties were investigated by photoacoustic absorption spectroscopy (PAS). The experimental results suggest that in as-milled nanocrystalline silicon for 10 h the heat transfer through the crystalline and interfacial components is similar, and after annealed at 470 {sup o}C the heat transfer is controlled by crystalline component.

  15. Photoacoustic study of nanocrystalline silicon produced by mechanical grinding

    International Nuclear Information System (INIS)

    Poffo, C.M.; Lima, J.C. de; Souza, S.M.; Triches, D.M.; Grandi, T.A.; Biasi, R.S. de

    2011-01-01

    Mechanical grinding (MG) was used to produce nanocrystalline silicon and its thermal and transport properties were investigated by photoacoustic absorption spectroscopy (PAS). The experimental results suggest that in as-milled nanocrystalline silicon for 10 h the heat transfer through the crystalline and interfacial components is similar, and after annealed at 470 o C the heat transfer is controlled by crystalline component.

  16. Grinding of WC-Co hard-metals

    NARCIS (Netherlands)

    Hegeman, J.B.J.W.; Hosson, de J.Th.M.; With, de G.

    2001-01-01

    Morphol. of ground surface of WC-Co cermets with 10 and 20% Co was studied. A deformed and detached surface layer was found on top of the specimens after surface grinding with a diamond wheel. Etching the surface layer revealed WC grains in the subsurface of the machined specimens. Most of these

  17. Grinding induced martensite on the surface of rails

    DEFF Research Database (Denmark)

    Rasmussen, C.J.; Zhang, Xiaodan; Danielsen, Hilmar Kjartansson

    2014-01-01

    determined. Two different rail types R260 and R350HT that both had been ground by a grinding train were investigated. The rail sections, studied using optical and scanning electron microscopy, showed that the surface of both types of rails is covered with WELs. The hardness of the WEL is increased compared...

  18. Grinding machine: Friend or Foe | Adigun | West African Journal of ...

    African Journals Online (AJOL)

    Few cases of traumatic loses of the external genitalia have been reported in this part of the world. In a developing country like ours, grinding machines are commonly being used by the people for domestic purposes. Children in their mid fifteens are usually employed to man and operate the machine without proper training ...

  19. Contact and Non-contact Measurements of Grinding Pins

    Directory of Open Access Journals (Sweden)

    Magdziak Marek

    2015-01-01

    Full Text Available The paper presents the results of contact and non-contact measurements of external profiles of selected grinding pins. The measurements were conducted in order to choose the appropriate measuring technique in the case of the considered measurement task. In the case of contact measurements the coordinate measuring machine ACCURA II was applied. The used coordinate measuring machine was equipped with the contact scanning probe VAST XT and the Calypso inspection software. Contact coordinate measurements were performed by using of different measurement strategies. The applied strategies included different scanning velocities and distances between measured points. Non-contact measurements were conducted by means of the tool presetter produced by the Mahr company. On the basis of gained results the guidelines concerning measurements of grinding pins were formulated. The measurements of analyzed grinding pins performed by means of the non-contact measuring system are characterized by higher reproducibility than the contact measurements. The low reproducibility of contact measurements may be connected with the inaccuracy of the selected coordinate measuring machine and the measuring probe, the measurement parameters and environmental conditions in the laboratory where the coordinate measuring machine is located. Moreover, the paper presents the possible application of results of conducted investigations. The results of non-contact measurements can be used in the simulation studies of grinding processes. The simulations may reduce the costs of machining processes.

  20. development and evaluation of a drill re-grinding fixture

    African Journals Online (AJOL)

    user

    as work holding device for re-grinding drills bits with diameter of at least 4.5 mm and above without ... cause normal stress to exceed yield stress of the material. ..... Institute of Rese r h nd sy hology”, Vol , pp 7 ... America Patent 10052968.

  1. Automatic programming of grinding robot restoration of contours

    Directory of Open Access Journals (Sweden)

    Are Willersrud

    1995-07-01

    Full Text Available A new programming method has been developed for grinding robots. Instead of using the conventional jog-and-teach method, the workpiece contour is automatically tracked by the robot. During the tracking, the robot position is stored in the robot control system every 8th millisecond. After filtering and reducing this contour data, a robot program is automatically generated.

  2. Automatic programming of grinding robot restoration of contours

    OpenAIRE

    Are Willersrud; Fred Godtliebsen; Trygve Thomessen

    1995-01-01

    A new programming method has been developed for grinding robots. Instead of using the conventional jog-and-teach method, the workpiece contour is automatically tracked by the robot. During the tracking, the robot position is stored in the robot control system every 8th millisecond. After filtering and reducing this contour data, a robot program is automatically generated.

  3. Nanofluid as coolant for grinding process: An overview

    Science.gov (United States)

    Kananathan, J.; Samykano, M.; Sudhakar, K.; Subramaniam, S. R.; Selavamani, S. K.; Manoj Kumar, Nallapaneni; Keng, Ngui Wai; Kadirgama, K.; Hamzah, W. A. W.; Harun, W. S. W.

    2018-04-01

    This paper reviews the recent progress and applications of nanoparticles in lubricants as a coolant (cutting fluid) for grinding process. The role of grinding machining in manufacturing and the importance of lubrication fluids during material removal are discussed. In grinding process, coolants are used to improve the surface finish, wheel wear, flush the chips and to reduce the work-piece thermal deformation. The conventional cooling technique, i.e., flood cooling delivers a large amount of fluid and mist which hazardous to the environment and humans. Industries are actively looking for possible ways to reduce the volume of coolants used in metal removing operations due to the economical and ecological impacts. Thus as an alternative, an advanced cooling technique known as Minimum Quantity Lubrication (MQL) has been introduced to the enhance the surface finish, minimize the cost, to reduce the environmental impacts and to reduce the metal cutting fluid consumptions. Nanofluid is a new-fangled class of fluids engineered by dispersing nanometre-size solid particles into base fluids such as water, lubrication oils to further improve the properties of the lubricant or coolant. In addition to advanced cooling technique review, this paper also reviews the application of various nanoparticles and their performance in grinding operations. The performance of nanoparticles related to the cutting forces, surface finish, tool wear, and temperature at the cutting zone are briefly reviewed. The study reveals that the excellent properties of the nanofluid can be beneficial in cooling and lubricating application in the manufacturing process.

  4. Development of the pellet grinding and inspection system

    International Nuclear Information System (INIS)

    Yamaguchi, Toshihiro; Kawasaki, Takao; Inui, Toshihiko; Yamada, Hiroyuki.

    1996-01-01

    The pellet grinding and inspection system is the facility of producing the MOX fuel for FBRs, and it was delivered in March, 1996 to the No. 3 Development Office of the plutonium fuel shop in Tokai of Power Reactor and Nuclear Fuel Development Corporation. This facility realized the high speed processing using the compact facility by combining the grinding of pellets, the inspection of outer density and appearance, the rationalization of the facility and the high performance automation equipment. The production processes of MOX comprise the processes of powder, sinter, finish and inspection, fabrication and assembling. The requirement for developing these facilities is shown. The features of this pellet grinding and inspection system are the compact facility by the combination of functions, high speed processing, the reduction of holdup in processes and the improvement of maintenance. These features are explained. The main components are simple sorting equipment, grinder, grinding dust recovering equipment, outside diameter and density sorting equipment and appearance inspection equipment. The constitution and the main functions of the control facility are described. The operational process is explained. (K.I.)

  5. Controlled wear of vitrified abrasive materials for precision grinding ...

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    2Machining Research Group, Department of Engineering, University of ... ods are applied to analyse the cutting mechanism in grinding. .... (d) Chemical reaction between abrasive and workpiece material at elevated temperatures ... most common method used for measuring wear flat area employs an optical, or an electron.

  6. short communication simple grinding-induced reactions of 2 ...

    African Journals Online (AJOL)

    Preferred Customer

    benzoxazine moiety features in the natural product terresoxazine isolated from Tribulus terrestris [12] and many other bioactive molecules [13-15]. Although several methods for the preparation of 1,3-oxazine derivatives have previously been reported [16-21] few have been focused on the solid-solid or solid-liquid grinding ...

  7. Grinding damage assessment for CAD-CAM restorative materials.

    Science.gov (United States)

    Curran, Philippe; Cattani-Lorente, Maria; Anselm Wiskott, H W; Durual, Stéphane; Scherrer, Susanne S

    2017-03-01

    To assess surface/subsurface damage after grinding with diamond discs on five CAD-CAM restorative materials and to estimate potential losses in strength based on crack size measurements of the generated damage. The materials tested were: Lithium disilicate (LIT) glass-ceramic (e.max CAD), leucite glass-ceramic (LEU) (Empress CAD), feldspar ceramic (VM2) (Vita Mark II), feldspar ceramic-resin infiltrated (EN) (Enamic) and a composite reinforced with nano ceramics (LU) (Lava Ultimate). Specimens were cut from CAD-CAM blocs and pair-wise mirror polished for the bonded interface technique. Top surfaces were ground with diamond discs of respectively 75, 54 and 18μm. Chip damage was measured on the bonded interface using SEM. Fracture mechanics relationships were used to estimate fracture stresses based on average and maximum chip depths assuming these to represent strength limiting flaws subjected to tension and to calculate potential losses in strength compared to manufacturer's data. Grinding with a 75μm diamond disc induced on a bonded interface critical chips averaging 100μm with a potential strength loss estimated between 33% and 54% for all three glass-ceramics (LIT, LEU, VM2). The softer materials EN and LU were little damage susceptible with chips averaging respectively 26μm and 17μm with no loss in strength. Grinding with 18μm diamond discs was still quite detrimental for LIT with average chip sizes of 43μm and a potential strength loss of 42%. It is essential to understand that when grinding glass-ceramics or feldspar ceramics with diamond discs surface and subsurface damage are induced which have the potential of lowering the strength of the ceramic. Careful polishing steps should be carried out after grinding especially when dealing with glass-ceramics. Copyright © 2017 The Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  8. Subsurface damage mechanism of high speed grinding process in single crystal silicon revealed by atomistic simulations

    International Nuclear Information System (INIS)

    Li, Jia; Fang, Qihong; Zhang, Liangchi; Liu, Youwen

    2015-01-01

    Highlights: • Molecular dynamic model of nanoscale high speed grinding of silicon workpiece has been established. • The effect of grinding speed on subsurface damage and grinding surface integrity by analyzing the chip, dislocation movement, and phase transformation during high speed grinding process are thoroughly investigated. • Subsurface damage is studied by the evolution of surface area at first time for more obvious observation on transition from ductile to brittle. • The hydrostatic stress and von Mises stress by the established analytical model are studied subsurface damage mechanism during nanoscale grinding. - Abstract: Three-dimensional molecular dynamics (MD) simulations are performed to investigate the nanoscale grinding process of single crystal silicon using diamond tool. The effect of grinding speed on subsurface damage and grinding surface integrity by analyzing the chip, dislocation movement, and phase transformation are studied. We also establish an analytical model to calculate several important stress fields including hydrostatic stress and von Mises stress for studying subsurface damage mechanism, and obtain the dislocation density on the grinding subsurface. The results show that a higher grinding velocity in machining brittle material silicon causes a larger chip and a higher temperature, and reduces subsurface damage. However, when grinding velocity is above 180 m s −1 , subsurface damage thickness slightly increases because a higher grinding speed leads to the increase in grinding force and temperature, which accelerate dislocation nucleation and motion. Subsurface damage is studied by the evolution of surface area at first time for more obvious observation on transition from ductile to brittle, that provides valuable reference for machining nanometer devices. The von Mises stress and the hydrostatic stress play an important role in the grinding process, and explain the subsurface damage though dislocation mechanism under high

  9. Performing in-feed type centerless grinding process on a surface grinder

    International Nuclear Information System (INIS)

    Xu, W.; Wu, Y.; Sato, T.; Lin, W.

    2011-01-01

    In our previous study, a new centerless grinding method using surface grinder was proposed. In this method, centerless grinding operations are performed by installing a compact centerless grinding unit, consisting mainly of an ultrasonic elliptic-vibration shoe, a blade and their respective holders, on the worktable of a surface grinder. During grinding, the cylindrical workpiece is held on the ultrasonic shoe and the blade, and its rotational motion is controlled by the elliptic motion of the shoe end-face. An actual unit had been produced and its performance in tangential-feed type centerless grinding using a surface grinder had been confirmed in the previous workd. In this paper, the performance of the grinding unit in in-feed centerless grinding operation was confirmed, and the effects of the main process parameter, i.e., eccentric angle, on the workpiece roundness was investigated experimentally. The obtained results showed that: (1) the centerless grinding unit performed well in in-feed type centerless grinding; (2) the eccentric angle affects roundness significantly, and its optimal angle is 6 deg.; (3) the workpiece roundness can be further improved by varying the eccentric angle during grinding, and the final roundness reached 0.65 μm after grinding as the eccentric angle varied from 9 deg. to 6 deg. and to 3 deg.

  10. A 6-DOF parallel bone-grinding robot for cervical disc replacement surgery.

    Science.gov (United States)

    Tian, Heqiang; Wang, Chenchen; Dang, Xiaoqing; Sun, Lining

    2017-12-01

    Artificial cervical disc replacement surgery has become an effective and main treatment method for cervical disease, which has become a more common and serious problem for people with sedentary work. To improve cervical disc replacement surgery significantly, a 6-DOF parallel bone-grinding robot is developed for cervical bone-grinding by image navigation and surgical plan. The bone-grinding robot including mechanical design and low level control is designed. The bone-grinding robot navigation is realized by optical positioning with spatial registration coordinate system defined. And a parametric robot bone-grinding plan and high level control have been developed for plane grinding for cervical top endplate and tail endplate grinding by a cylindrical grinding drill and spherical grinding for two articular surfaces of bones by a ball grinding drill. Finally, the surgical flow for a robot-assisted cervical disc replacement surgery procedure is present. The final experiments results verified the key technologies and performance of the robot-assisted surgery system concept excellently, which points out a promising clinical application with higher operability. Finally, study innovations, study limitations, and future works of this present study are discussed, and conclusions of this paper are also summarized further. This bone-grinding robot is still in the initial stage, and there are many problems to be solved from a clinical point of view. Moreover, the technique is promising and can give a good support for surgeons in future clinical work.

  11. Flotation performances and surface properties of chalcopyrite with xanthate collector added before and after grinding

    Science.gov (United States)

    Peng, Huiqing; Wu, Di; Abdelmonem, Mohamed

    In this study, effects of the collector added before grinding and after grinding on the subsequent flotation and mineral surface properties were investigated. The pH was controlled at 10 during the grinding and flotation processes opened to the atmosphere. With enough amounts of sodium butyl xanthate addition, adding the collector before grinding recovered more chalcopyrite than adding it after grinding in single mineral flotation. The Eh of each ground pulp before and after conditioning were measured and it was found that adding collector before grinding obtained higher and relatively suitable pulp potential for chalcopyrite flotation. Particle size analyses of the flotation products indicate that the different flotation recoveries occurred due to the different flotation losses in fine particles (flotation feedings and found that more carbon and oxygen, and less iron were remained on mineral surfaces when the collector was added before grinding, due to the higher collector adsorption capacity, larger free oxygen adsorbance and less iron oxide/hydroxide species.

  12. Development of a grinding-specific performance test set-up

    DEFF Research Database (Denmark)

    Olesen, C. G.; Larsen, B. H.; Andresen, E. L.

    2015-01-01

    The aim of this study was to develop a performance test set-up for America's Cup grinders. The test set-up had to mimic the on-boat grinding activity and be capable of collecting data for analysis and evaluation of grinding performance. This study included a literature-based analysis of grinding...... demands and a test protocol developed to accommodate the necessary physiological loads. This study resulted in a test protocol consisting of 10 intervals of 20 revolutions each interspersed with active resting periods of 50 s. The 20 revolutions are a combination of both forward and backward grinding...... and an exponentially rising resistance. A custom-made grinding ergometer was developed with computer-controlled resistance and capable of collecting data during the test. The data collected can be used to find measures of grinding performance such as peak power, time to complete and the decline in repeated grinding...

  13. Development of a grinding-specific performance test set-up.

    Science.gov (United States)

    Olesen, C G; Larsen, B H; Andresen, E L; de Zee, M

    2015-01-01

    The aim of this study was to develop a performance test set-up for America's Cup grinders. The test set-up had to mimic the on-boat grinding activity and be capable of collecting data for analysis and evaluation of grinding performance. This study included a literature-based analysis of grinding demands and a test protocol developed to accommodate the necessary physiological loads. This study resulted in a test protocol consisting of 10 intervals of 20 revolutions each interspersed with active resting periods of 50 s. The 20 revolutions are a combination of both forward and backward grinding and an exponentially rising resistance. A custom-made grinding ergometer was developed with computer-controlled resistance and capable of collecting data during the test. The data collected can be used to find measures of grinding performance such as peak power, time to complete and the decline in repeated grinding performance.

  14. Fine grinding of brittle minerals and materials by jet mill

    Directory of Open Access Journals (Sweden)

    Lek Sikong

    2008-05-01

    Full Text Available Various variables affecting grinding, such as air pressure, minerals or materials hardness, feed size were investigated.The limitations of grinding of gypsum, barite, ilmenite, quartz and ferrosilicon were also elucidated by means of particlefineness size distribution and morphology of ground products. It was found that:1 The density of particles, which are in the grinding zone affects the product fineness, i.e. higher feed rate resultsin a larger product size. The appropriate feed rate is suggested to be 0.2~0.5 g/s. Moreover, the density and hardness ofminerals or materials tend to have an effect on the product fineness. Heavy minerals, such as barite or ilmenite, exhibit afiner product size than lighter minerals, like quartz. However, for quartz, the higher hardness also results in a larger d50.2 Air pressure is the most vital variable which affects the grinding by a jet mill. The d50 seems to relate to theapplied air pressure as a power law equation expressed as following:d50 = aP b ; as P 0The a-value and b-value have been found to correlate to the feed size. The higher the air pressure applied the finerthe product size attained. Moreover, air pressure has a greater effect on hard minerals than on softer ones.3 Feed size seems to have a small effect on ground the product fineness of soft materials, such as gypsum andbarite, but a significant effect on that of hard materials, such as ferrosilicon and quartz, in particularly by milling at low airpressures of 2~3 kg/cm2.4 For the breakage behavior and morphology of ground materials, it was also found that the minerals having cleavages,such as gypsum and barite, tend to be broken along their cleavage planes. Thus, the particle size distribution of theseproducts becomes narrower. While quartz, ilmenite, and ferrosilicon have shattering and chipping breakage mechanisms,grinding results in angular shapes of the ground products and a wider size distribution. Blocks or platelets and

  15. Experimental Investigation on the Performance of Grinding Assisted Electrochemical Discharge Drilling of Glass

    Directory of Open Access Journals (Sweden)

    Ladeesh V G

    2016-01-01

    Full Text Available Grinding assisted electrochemical discharge drilling (G-ECDD is a novel technique for producing micro and macro holes in brittle materials including advanced ceramics and glass, both efficiently and economically. G-ECDD involves the use of a rotating diamond core drill as the tool in a normal electrochemical discharge machine setup. The material removal happens by a combination of thermal melting due to electric discharges, followed by grinding action of diamond grits and chemical etching action. In this study, the effect of process parameters like voltage, duty cycle, cycle time and electrolyte concentration on material removed (MR was investigated systematically using response surface methodology. Analysis of variance was performed to identify the significant factors and their percentage contribution. The most significant factor was found to be duty cycle followed by voltage, cycle time and concentration. A quadratic mathematical model was developed to predict MR. Tool wear was found for different frequencies and voltages. Higher tool wear was observed for high frequency above 5kHz pulsed DC supply at high voltage of 110V. Tool wear at the end face of the tool was found to be a significant problem affecting the tool life.

  16. Establishment of cocrystal cocktail grinding method for rational screening of pharmaceutical cocrystals.

    Science.gov (United States)

    Yamamoto, Katsuhiko; Tsutsumi, Shunichirou; Ikeda, Yukihiro

    2012-11-01

    Cocrystals (CCs) used in the pharmaceutical industry are defined as complex crystals formed by reaction between an API and a cocrystal former (CCF); unlike salts, CCs do not show proton transfer. Recently, pharmaceutical CCs have been used to improve the drug-likeness of APIs, such as solubility and stability. Grinding is more effective for CC synthesis than crystallization from solution because in the former case, the API can predominantly interact with the CCF without being affected by solvents. However, this method is tedious because the API is ground with only one CCF at a time. We developed a cocktail cocrystal grinding (CCG) method, in which a mixture of CCFs having the same functional group was used. No false negatives/positives were observed in CCG when carbamazepine was used as the model compound. This method could be used to obtain CCs of piroxicam and spironolactone. False negatives were observed for only one compound from among three model compounds, indicating that CCG facilitates efficient CC detection and that it has higher throughput than does the conventional method. Further, CCG is fast and suitable for rational CC screening, and it helps identify the partial structure of CCFs that forms synthons with an API. Copyright © 2012 Elsevier B.V. All rights reserved.

  17. Fatigue limit of polycrystalline zirconium oxide ceramics: Effect of grinding and low-temperature aging.

    Science.gov (United States)

    Pereira, G K R; Silvestri, T; Amaral, M; Rippe, M P; Kleverlaan, C J; Valandro, L F

    2016-08-01

    The following study aimed to evaluate the effect of grinding and low-temperature aging on the fatigue limit of Y-TZP ceramics for frameworks and monolithic restorations. Disc specimens from each ceramic material, Lava Frame (3M ESPE) and Zirlux FC (Ivoclar Vivadent) were manufactured according to ISO:6872-2008 and assigned in accordance with two factors: (1) "surface treatment"-without treatment (as-sintered, Ctrl), grinding with coarse diamond bur (181µm; Grinding); and (2) "low-temperature aging (LTD)" - presence and absence. Grinding was performed using a contra-angle handpiece under constant water-cooling. LTD was simulated in an autoclave at 134°C under 2-bar pressure for 20h. Mean flexural fatigue limits (20,000 cycles) were determined under sinusoidal loading using stair case approach. For Lava ceramic, it was observed a statistical increase after grinding procedure and different behavior after LTD stimuli (Ctrl<Grinding; CtrlGrinding=Grinding Ltd); while for Zirlux, grinding and low-temperature aging promoted a statistical increase in the fatigue limit (Ctrl<Grinding; CtrlGrinding Ltd). An important increase was observed in m-phase content after both stimuli (grinding and LTD), although with different intensities. Additionally, fatigue test did not promote increase of m-phase content. Thus, tested grinding and low temperature aging did not damage the fatigue limit values significantly for both materials evaluated, even though those conditions promoted increase in m-phase. Copyright © 2016 Elsevier Ltd. All rights reserved.

  18. Experimental verification of nanoparticle jet minimum quantity lubrication effectiveness in grinding

    International Nuclear Information System (INIS)

    Jia, Dongzhou; Li, Changhe; Zhang, Dongkun; Zhang, Yanbin; Zhang, Xiaowei

    2014-01-01

    In our experiment, K-P36 precision numerical control surface grinder was used for dry grinding, minimum quantity lubrication (MQL) grinding, nanoparticle jet MQL grinding, and traditional flood grinding of hardened 45 steel. A three-dimensional dynamometer was used to measure grinding force in the experiment. In this research, experiments were conducted to measure and calculate specific tangential grinding force, frictional coefficient, and specific grinding energy, thus verifying the lubrication performance of nanoparticles in surface grinding. Findings present that compared with dry grinding, the specific tangential grinding force of MQL grinding, nanoparticle jet MQL grinding, and flood grinding decreased by 45.88, 62.34, and 69.33 %, respectively. Their frictional coefficient was reduced by 11.22, 29.21, and 32.18 %, and the specific grinding energy declined by 45.89, 62.34, and 69.45 %, respectively. Nanoparticle jet MQL presented ideal lubrication effectiveness, which was attributed to the friction oil film with strong antifriction and anti-wear features formed by nanoparticles on the grinding wheel/workpiece interface. Moreover, lubricating properties of nanoparticles of the same size (50 nm) but different types were verified through experimentation. In our experiment, ZrO 2 nanoparticles, polycrystal diamond (PCD) nanoparticles, and MoS 2 nanoparticles were used in the comparison of nanoparticle jet MQL grinding. The experimental results manifest that MoS 2 nanoparticles exhibited the optimal lubricating effectiveness, followed by PCD nanoparticles. Our research also integrated the properties of different nanoparticles to analyze the lubrication mechanisms of different nanoparticles. The experiment further verified the impact of nanoparticle concentration on the effectiveness of nanoparticle jet MQL in grinding. The experimental results demonstrate that when the nanoparticle mass fraction was 6 %, the minimum specific tangential grinding force

  19. Enhancing the color gamut of white displays using novel deep-blue organic fluorescent dyes to form color-changed thin films with improved efficiency

    Science.gov (United States)

    Liu, Wei-Ting; Huang, Wen-Yao

    2012-10-01

    This study used the novel fluorescence based deep-blue-emitting molecule BPVPDA in an organic fluorescent color thin film to exhibit deep blue color with CIE coordinates of (0.13, 0.16). The developed original organic RGB color thin film technology enables the optimization of the distinctive features of an organic light emitting diode (OLED) and thin-film-transistor (TFT) LCD display. The color filter structure maintains the same high resolution to obtain a higher level of brightness in comparison with conventional organic RGB color thin film. The image-processing engine is designed to achieve a sharp text image for a TFT LCD with organic color thin films. The organic color thin films structure uses an organic dye dopant in a limpid photoresist. With this technology, the following characteristics can be obtained: 1. high color reproduction of gamut ratio, and 2. improved luminous efficiency with organic color fluorescent thin film. This performance is among the best results ever reported for a color-filter used on TFT-LCD or OLED.

  20. Effect of Superfine Grinding on Physicochemical Properties of Apple Pomace

    International Nuclear Information System (INIS)

    Liang, X.; Sun, J.; Ma, H.

    2016-01-01

    The effect of superfine grinding on the physicochemical properties of apple pomace was investigated in this study. The optimal ultrafine powder could be obtained under the conditions of motor speed 450 rpm and fan speed 300 rpm, whose particle size, water-solubility index, angle of repose, total phenolic content and total sugar content were 10.23±0.42 micro m, 33.65±0.91 percent, 39.36±1.59 degree, 12.62±0.34 mg GAE/g and 136.14±3.1 mg/g, respectively. Compared with the traditional powder, the significant increase of water-solubility, total phenolic content and total sugar content could be found while the decrease of angle of repose could be observed. It could be concluded that the bioavailability of functional and nutritional ingredients of apple pomace could be significantly improved by superfine grinding. (author)

  1. Grinding damage assessment on four high-strength ceramics.

    Science.gov (United States)

    Canneto, Jean-Jacques; Cattani-Lorente, Maria; Durual, Stéphane; Wiskott, Anselm H W; Scherrer, Susanne S

    2016-02-01

    The purpose of this study was to assess surface and subsurface damage on 4 CAD-CAM high-strength ceramics after grinding with diamond disks of 75 μm, 54 μm and 18 μm and to estimate strength losses based on damage crack sizes. The materials tested were: 3Y-TZP (Lava), dense Al2O3 (In-Ceram AL), alumina glass-infiltrated (In-Ceram ALUMINA) and alumina-zirconia glass-infiltrated (In-Ceram ZIRCONIA). Rectangular specimens with 2 mirror polished orthogonal sides were bonded pairwise together prior to degrading the top polished surface with diamond disks of either 75 μm, 54 μm or 18 μm. The induced chip damage was evaluated on the bonded interface using SEM for chip depth measurements. Fracture mechanics were used to estimate fracture stresses based on average and maximum chip depths considering these as critical flaws subjected to tension and to calculate possible losses in strength compared to manufacturer's data. 3Y-TZP was hardly affected by grinding chip damage viewed on the bonded interface. Average chip depths were of 12.7±5.2 μm when grinding with 75 μm diamond inducing an estimated loss of 12% in strength compared to manufacturer's reported flexural strength values of 1100 MPa. Dense alumina showed elongated chip cracks and was suffering damage of an average chip depth of 48.2±16.3 μm after 75 μm grinding, representing an estimated loss in strength of 49%. Grinding with 54 μm was creating chips of 32.2±9.1 μm in average, representing a loss in strength of 23%. Alumina glass-infiltrated ceramic was exposed to chipping after 75 μm (mean chip size=62.4±19.3 μm) and 54 μm grinding (mean chip size=42.8±16.6 μm), with respectively 38% and 25% estimated loss in strength. Alumina-zirconia glass-infiltrated ceramic was mainly affected by 75 μm grinding damage with a chip average size of 56.8±15.1 μm, representing an estimated loss in strength of 34%. All four ceramics were not exposed to critical chipping at 18 μm diamond grinding. Reshaping a

  2. Chemical treatment of coal by grinding and aqueous caustic leaching

    Energy Technology Data Exchange (ETDEWEB)

    Balaz, P.; LaCount, R.B.; Kern, D.G.; Turcaniova, L. [Slovak Academy of Sciences, Kosice (Slovakia). Inst. of Geotechnics

    2001-04-01

    The aim of this work has been to point out the possibility of using GACL process for chemical cleaning of brown coal Nivaky (Slovakia) and Pittsburgh coal. Simultaneous grinding and aqueous chemical leaching, which is the principle of the process, reduces the inorganic and inorganic sulfur content in both coals. Dearsenificiation nearly up to 96% is detected in GACL-treated samples of Novaky coal. The possibility of enhancing the recovery of humic acid as a consequence of GACL treatment is demonstrated. The process under study works under atmospheric pressure, temperature of 90{degree}C and NaOH consumption, which is six times lower compared with the MCL process. Further research is needed to minimize the wear of grinding media and to improve the washing step. 24 refs., 7 figs., 3 tabs.

  3. Manufacturing and sustainability of bonding systems for grinding tools

    OpenAIRE

    Linke, B

    2016-01-01

    © 2016, German Academic Society for Production Engineering (WGP). Grinding and honing processes are quality-defining operations in the production of many modern products. Process performance and product quality are contingent on selecting the correct abrasive tool for a specific application. Thus, tools with different bonding systems are used, namely resin bonded tools, vitrified bonded tools, and metallic bonded tools. Tool manufacturers have great knowledge in the choice and intricate prod...

  4. Westinghouse modular grinding process - improvement for follow on processes

    International Nuclear Information System (INIS)

    Fehrmann, Henning

    2013-01-01

    In nuclear power plants (NPP) ion exchange (IX) resins are used in several systems for water treatment. The resins can be in bead or powdered form. For waste treatment of spent IX resins, two methods are basically used: Direct immobilization (e.g. with cement, bitumen, polymer or High Integrity Container (HIC)); Thermal treatment (e.g. drying, oxidation or pyrolysis). Bead resins have some properties (e.g. particle size and density) that can have negative impacts on following waste treatment processes. Negative impacts could be: Floatation of bead resins in cementation process; Sedimentation in pipeline during transportation; Poor compaction properties for Hot Resin Supercompaction (HRSC). Reducing the particle size of the bead resins can have beneficial effects enhancing further treatment processes and overcoming prior mentioned effects. Westinghouse Electric Company has developed a modular grinding process to crush/grind the bead resins. This modular process is designed for flexible use and enables a selective adjustment of particle size to tailor the grinding system to the customer needs. The system can be equipped with a crusher integrated in the process tank and if necessary a colloid mill. The crusher reduces the bead resins particle size and converts the bead resins to a pump able suspension with lower sedimentation properties. With the colloid mill the resins can be ground to a powder. Compared to existing grinding systems this equipment is designed to minimize radiation exposure of the worker during operation and maintenance. Using the crushed and/or ground bead resins has several beneficial effects like facilitating cementation process and recipe development, enhancing oxidation of resins, improving the Hot Resin Supercompaction volume reduction performance. (authors)

  5. Westinghouse modular grinding process - improvement for follow on processes

    Energy Technology Data Exchange (ETDEWEB)

    Fehrmann, Henning [Westinghouse Germany GmbH, Mannheim, State (Germany)

    2013-07-01

    In nuclear power plants (NPP) ion exchange (IX) resins are used in several systems for water treatment. The resins can be in bead or powdered form. For waste treatment of spent IX resins, two methods are basically used: Direct immobilization (e.g. with cement, bitumen, polymer or High Integrity Container (HIC)); Thermal treatment (e.g. drying, oxidation or pyrolysis). Bead resins have some properties (e.g. particle size and density) that can have negative impacts on following waste treatment processes. Negative impacts could be: Floatation of bead resins in cementation process; Sedimentation in pipeline during transportation; Poor compaction properties for Hot Resin Supercompaction (HRSC). Reducing the particle size of the bead resins can have beneficial effects enhancing further treatment processes and overcoming prior mentioned effects. Westinghouse Electric Company has developed a modular grinding process to crush/grind the bead resins. This modular process is designed for flexible use and enables a selective adjustment of particle size to tailor the grinding system to the customer needs. The system can be equipped with a crusher integrated in the process tank and if necessary a colloid mill. The crusher reduces the bead resins particle size and converts the bead resins to a pump able suspension with lower sedimentation properties. With the colloid mill the resins can be ground to a powder. Compared to existing grinding systems this equipment is designed to minimize radiation exposure of the worker during operation and maintenance. Using the crushed and/or ground bead resins has several beneficial effects like facilitating cementation process and recipe development, enhancing oxidation of resins, improving the Hot Resin Supercompaction volume reduction performance. (authors)

  6. Co-grinding Effect on Crystalline Zaltoprofen with β-cyclodextrin/Cucurbit[7]uril in Tablet Formulation

    Science.gov (United States)

    Li, Shanshan; Lin, Xiang; Xu, Kailin; He, Jiawei; Yang, Hongqin; Li, Hui

    2017-04-01

    This work aimed to investigate the co-grinding effects of β-cyclodextrin (β-CD) and cucurbit[7]uril (CB[7]) on crystalline zaltoprofen (ZPF) in tablet formulation. Crystalline ZPF was prepared through anti-solvent recrystallization and fully analyzed through single-crystal X-ray diffraction. Co-ground dispersions and mono-ground ZPF were prepared using a ball grinding process. Results revealed that mono-ground ZPF slightly affected the solid state, solubility, and dissolution of crystalline ZPF. Co-ground dispersions exhibited completely amorphous states and elicited a significant reinforcing effect on drug solubility. UV-vis spectroscopy, XRPD, FT-IR, DSC, ssNMR, and molecular docking demonstrated the interactions in the amorphous product. Hardness tests on blank tablets with different β-CD and CB[7] contents suggested the addition of β-CD or CB[7] could enhance the compressibility of the powder mixture. Disintegration tests showed that CB[7] could efficiently shorten the disintegrating time. Dissolution tests indicated that β-CD and CB[7] could accelerate the drug dissolution rate via different mechanisms. Specifically, CB[7] could accelerate the dissolution rate by improving disintegration and β-CD showed a distinct advantage in solubility enhancement. Based on the comparative study on β-CD and CB[7] for tablet formulation combined with co-grinding, we found that CB[7] could be considered a promising drug delivery, which acted as a disintegrant.

  7. Co-grinding Effect on Crystalline Zaltoprofen with β-cyclodextrin/Cucurbit[7]uril in Tablet Formulation

    Science.gov (United States)

    Li, Shanshan; Lin, Xiang; Xu, Kailin; He, Jiawei; Yang, Hongqin; Li, Hui

    2017-01-01

    This work aimed to investigate the co-grinding effects of β-cyclodextrin (β-CD) and cucurbit[7]uril (CB[7]) on crystalline zaltoprofen (ZPF) in tablet formulation. Crystalline ZPF was prepared through anti-solvent recrystallization and fully analyzed through single-crystal X-ray diffraction. Co-ground dispersions and mono-ground ZPF were prepared using a ball grinding process. Results revealed that mono-ground ZPF slightly affected the solid state, solubility, and dissolution of crystalline ZPF. Co-ground dispersions exhibited completely amorphous states and elicited a significant reinforcing effect on drug solubility. UV-vis spectroscopy, XRPD, FT-IR, DSC, ssNMR, and molecular docking demonstrated the interactions in the amorphous product. Hardness tests on blank tablets with different β-CD and CB[7] contents suggested the addition of β-CD or CB[7] could enhance the compressibility of the powder mixture. Disintegration tests showed that CB[7] could efficiently shorten the disintegrating time. Dissolution tests indicated that β-CD and CB[7] could accelerate the drug dissolution rate via different mechanisms. Specifically, CB[7] could accelerate the dissolution rate by improving disintegration and β-CD showed a distinct advantage in solubility enhancement. Based on the comparative study on β-CD and CB[7] for tablet formulation combined with co-grinding, we found that CB[7] could be considered a promising drug delivery, which acted as a disintegrant. PMID:28368030

  8. Quantifying the Contribution of Urban-Industrial Efficiency and Symbiosis to Deep Decarbonization: Impact of 637 Chinese Cities

    Science.gov (United States)

    Ramaswami, A.; Tong, K.; Fang, A.; Lal, R.; Nagpure, A.; Li, Y.; Yu, H.; Jiang, D.; Russell, A. G.; Shi, L.; Chertow, M.; Wang, Y.; Wang, S.

    2016-12-01

    Urban activities in China contribute significantly to global greenhouse gas (GHG) emissions and to local air pollution-related health risks. Co-location analysis can help inform the potential for energy- and material-exchanges across homes, businesses, infrastructure and industries co-located in cities. Such co-location dependent urban-industrial symbiosis strategies offer a new pathway toward urban energy efficiency and health that have not previously been quantified. Key examples includes the use of waste industrial heat in other co-located industries, and in residential-commercial district heating-cooling systems of cities. To quantify the impact of these strategies: (1) We develop a new data-set of 637 Chinese cities to assess the potential for efficiency and symbiosis across co-located homes, businesses, industries and the energy and construction sectors in the different cities. (2) A multi-scalar urban systems model quantifies trans-boundary CO2 impacts as well as local health benefits of these uniquely urban, co-location-dependent strategies. (3) CO2 impacts are aggregated across the 637 Chinese cities (home to 701 million people) to quantify national CO2 mitigation potential. (4) The local health benefits are modeled specific to each city and mapped geospatially to identify areas where co-benefits between GHG mitigation and health are maximized. Results: A first order conservative analysis of co-location dependent urban symbiosis indicates potential for reducing 6% of China's national total CO2 emissions in a relatively short time period, yielding a new pathway not previously considered in China's energy futures models. The magnitude of these reductions (6%) was similar in magnitude to sector specific industrial, power sector and buildings efficiency strategeies that together contributed 9% CO2 reduction aggregated across the nation. CO2 reductions mapped to the 637 cities ranged from 40,000 premature deaths (avoided) across all cities. These results

  9. Possibilities of Pelletizing and Briquetting of Dusts from Castings Grinding

    Directory of Open Access Journals (Sweden)

    A. Pribulová

    2010-04-01

    Full Text Available Foundry dust can be divided into three groups: metallic dust with Fe content over 70%, mixed dust with Fe or SiO2 content between 10 –70% and sand wastes with minimum content of SiO2 about 70%. Dust from castings grinding with high Fe content (87.9% is still landfillin Slovakia. The aim of experiments with dust from grinding has been to find the cheapest way of dust agglomeration with minimumamount of binder because of melting in the electric induction furnace. The dust was pelletized and briquetted and as binders bentonite, water glass and cement were used. Briquettes made from dust from grinding with addition of water glass got compression strength after three months on the air about 82 kPa. Briquettes with addition of water glass were melted together with cast iron in electric induction furnace. Yield of metal from briquettes was around 80% and slag quantity around 4% (without briquettes the slag quantity was 1.4%.

  10. Preparation and characterization of Dendrobium officinale powders through superfine grinding.

    Science.gov (United States)

    Meng, Qingran; Fan, Haoran; Chen, Feng; Xiao, Tiancun; Zhang, Lianfu

    2018-03-01

    Dendrobium officinale has been used in China for several thousand years as a health food and has become one of the most expensive tea materials worldwide as a result of extremely scarce resources in the wild and an increasing demand. Hence, it is very important to improve the depth and width of its application. In the present study, the physico-chemical, surface chemistry and thermal properties of micron range particles and coarse particles prepared by superfine grinding and shear pulverization were investigated. As the particle size decreased, the specific surface area of D. officinale powders increased significantly. Microscopy observations confirmed that superfine grinding effectively changed the original structure of D. officinale. The Fourier transform infrared spectroscopy spectra depicted the characteristic bands shifted in terms of absorbance and/or wave number as the powder particle size decreased. The crystallinity and intensity of the crystal peaks of D. officinale powders increased as the particle size decreased. Moisture sorption isotherms suggested that superfine powders were more unstable as a result of the increase in surface area, as well as the exposure of polar groups. The results of the present study suggest that superfine grinding may provide new methods of processing for D. officinale with respect to further enhancement of its application value. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  11. Rotary ultrasonic machining of CFRP: A comparison with grinding.

    Science.gov (United States)

    Ning, F D; Cong, W L; Pei, Z J; Treadwell, C

    2016-03-01

    Carbon fiber reinforced plastic (CFRP) composites have been intensively used in various industries due to their superior properties. In aircraft and aerospace industry, a large number of holes are required to be drilled into CFRP components at final stage for aircraft assembling. There are two major types of methods for hole making of CFRP composites in industry, twist drilling and its derived multi-points machining methods, and grinding and its related methods. The first type of methods are commonly used in hole making of CFRP composites. However, in recent years, rotary ultrasonic machining (RUM), a hybrid machining process combining ultrasonic machining and grinding, has also been successfully used in drilling of CFRP composites. It has been shown that RUM is superior to twist drilling in many aspects. However, there are no reported investigations on comparisons between RUM and grinding in drilling of CFRP. In this paper, these two drilling methods are compared in five aspects, including cutting force, torque, surface roughness, hole diameter, and material removal rate. Copyright © 2015 Elsevier B.V. All rights reserved.

  12. Measurement of drill grinding parameters using laser sensor

    Science.gov (United States)

    Yanping, Peng; Kumehara, Hiroyuki; Wei, Zhang; Nomura, Takashi

    2005-12-01

    To measure the grinding parameters and geometry parameters accurately for a drill point is essential to its design and reconditioning. In recent years, a number of non-contact coordinate measuring apparatuses, using CCD camera or laser sensors, are developed. But, a lot work is to be done for further improvement. This paper reports another kind of laser coordinate meter. As an example of its application, the method for geometry inspection of the drill flank surface is detailed. Measured data from laser scanning on the flank surface around some points with several 2-dimensional curves are analyzed with mathematical procedure. If one of these curves turns to be a straight line, it must be the generatrix of the grinding cone. Thus, the grinding parameters are determined by a set of three generatrices. Then, the measurement method and data processing procedure are proposed. Its validity is assessed by measuring a sample with given parameters. The point geometry measured agrees well with the known values. In comparison with other methods in the published literature, it is simpler in computation and more accurate in results.

  13. Technological support of tool wear resistant qualities and cost saving of process of planetary grinding of flat parts

    Science.gov (United States)

    Ivanova, T. N.; Lyupa, D. C.; Revenko, N. F.; Berkutova, T. A.; Silivanova, O. A.

    2018-03-01

    A lot of factors varied in time lead to instability of the grinding process. Besides, the method of grinding influences significantly the productivity and quality of processing. In this regard a creation of processes of intensive defect-free grinding on the basis of new constructive and technology solutions represents the scientific problem which is of great importance. One of such solutions is application of planetary face grinding which allows simultaneously changing the kinematics of movement, implementing discontinuous grinding. The distinctive features of such grinding are decreasing the heat release rate in a contact zone; ensuring intermittence of the process with a solid grinding wheel; reverse grinding; cutting by different edges of an abrasive grain; stabilization of working parameters of a grinding wheel; ensuring work of a grinding wheel in a self-sharpening mode. The design of the planetary grinding tool was developed for plane surface processing for implementation of the specified distinctive features of planetary grinding. The kinematics of shaping a surface by flat face diamond grinding has been investigated; manufacturing capabilities of planetary face grinding have been revealed, and ways of improvement of quality and productivity have been offered. The algorithm and the program to define the motion path of a grain depending on the given set of grinding factors were received. Optimization of the process of face diamond grinding using the planetary grinding device has been confirmed with the developed program and techniques to choose cutting conditions of planetary grinding and characteristics of grinding wheels for processing different materials. While studying the process of planetary grinding, special attention was paid to the research how processing conditions influence microgeometry of the processed surface made of steel 4X5M (Russian State Standard (GOST)). As a result of the executed research, it was established that surface roughness

  14. Y-TZP zirconia regeneration firing: Microstructural and crystallographic changes after grinding.

    Science.gov (United States)

    Ryan, Daniel Patrick Obelenis; Fais, Laiza Maria Grassi; Antonio, Selma Gutierrez; Hatanaka, Gabriel Rodrigues; Candido, Lucas Miguel; Pinelli, Ligia Antunes Pereira

    2017-07-26

    This study evaluated microstructural and crystallographic phase changes after grinding (G) and regeneration firing/anneling (R) of Y-TZP ceramics. Thirty five bars (Lava TM and Ice Zirkon) were divided: Y-TZP pre-sintered, control (C), regeneration firing (R), dry grinding (DG), dry grinding+regeneration firing (DGR), wet grinding (WG) and wet grinding+regeneration firing (WGR). Grinding was conducted using a diamond bur and annealing at 1,000°C. The microstructure was analyzed by SEM and the crystalline phases by X-ray diffraction (XRD). XRD showed that pre-sintered specimens contained tetragonal and monoclinic phases, while groups C and R showed tetragonal, cubic and monoclinic phases. After grinding, the cubic phase was eliminated in all groups. Annealing (DGR and WGR) resulted in only tetragonal phase. SEM showed semi-circular cracks after grinding and homogenization of particles after annealing. After grinding, surfaces show tetragonal and monoclinic phases and R can be assumed to be necessary prior to porcelain layering when grinding is performed.

  15. Grinding model and material removal mechanism of medical nanometer zirconia ceramics.

    Science.gov (United States)

    Zhang, Dongkun; Li, Changhe; Jia, Dongzhou; Wang, Sheng; Li, Runze; Qi, Xiaoxiao

    2014-01-01

    Many patents have been devoted to developing medical nanometer zirconia ceramic grinding techniques that can significantly improve both workpiece surface integrity and grinding quality. Among these patents is a process for preparing ceramic dental implants with a surface for improving osseo-integration by sand abrasive finishing under a jet pressure of 1.5 bar to 8.0 bar and with a grain size of 30 µm to 250 µm. Compared with other materials, nano-zirconia ceramics exhibit unmatched biomedical performance and excellent mechanical properties as medical bone tissue and dentures. The removal mechanism of nano-zirconia materials includes brittle fracture and plastic removal. Brittle fracture involves crack formation, extension, peeling, and chipping to completely remove debris. Plastic removal is similar to chip formation in metal grinding, including rubbing, ploughing, and the formation of grinding debris. The materials are removed in shearing and chipping. During brittle fracture, the grinding-led transverse and radial extension of cracks further generate local peeling of blocks of the material. In material peeling and removal, the mechanical strength and surface quality of the workpiece are also greatly reduced because of crack extension. When grinding occurs in the plastic region, plastic removal is performed, and surface grinding does not generate grinding fissures and surface fracture, producing clinically satisfactory grinding quality. With certain grinding conditions, medical nanometer zirconia ceramics can be removed through plastic flow in ductile regime. In this study, we analyzed the critical conditions for the transfer of brittle and plastic removal in nano-zirconia ceramic grinding as well as the high-quality surface grinding of medical nanometer zirconia ceramics by ELID grinding.

  16. A Zero-Dimensional Organic Seesaw-Shaped Tin Bromide with Highly Efficient Strongly Stokes-Shifted Deep-Red Emission

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Chenkun [College of Engineering, Tallahassee, FL (United States). Dept. of Chemical and Biomedical Engineering; Lin, Haoran [College of Engineering, Tallahassee, FL (United States). Dept. of Chemical and Biomedical Engineering; Shi, Hongliang [Beihang Univ., Beijing (China). Dept. of Physics; Tian, Yu [Materials Science and Engineering Program, Florida State University, Tallahassee FL 32306 USA; Pak, Chongin [Florida State Univ., Tallahassee, FL (United States). Dept. of Chemistry and Biochemistry; Shatruk, Michael [Florida State Univ., Tallahassee, FL (United States). Dept. of Chemistry and Biochemistry; Zhou, Yan [Florida State Univ., Tallahassee, FL (United States). Dept. of Chemistry and Biochemistry; Djurovich, Peter [Univ. of Southern California, Los Angeles, CA (United States). Dept. of Chemistry; Du, Mao-Hua [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Materials Science and Technology Division, Center for Radiation Detection Materials and Systems; Ma, Biwu [College of Engineering, Tallahassee, FL (United States). Dept. of Chemical and Biomedical Engineering; Beihang Univ., Beijing (China). Dept. of Physics; Florida State Univ., Tallahassee, FL (United States). Dept. of Chemistry and Biochemistry

    2017-12-21

    The synthesis and characterization is reported of (C9NH20)2SnBr4, a novel organic metal halide hybrid with a zero-dimensional (0D) structure, in which individual seesaw-shaped tin (II) bromide anions (SnBr42-) are co-crystallized with 1-butyl-1-methylpyrrolidinium cations (C9NH20+). Upon photoexcitation, the bulk crystals exhibit a highly efficient broadband deep-red emission peaked at 695 nm, with a large Stokes shift of 332 nm and a high quantum efficiency of around 46 %. Furthermore, the unique photophysical properties of this hybrid material are attributed to two major factors: 1) the 0D structure allowing the bulk crystals to exhibit the intrinsic properties of individual SnBr42- species, and 2) the seesaw structure then enables a pronounced excited state structural deformation as confirmed by density functional theory (DFT) calculations.

  17. Hydrophilic Conjugated Polymers with Large Bandgaps and Deep-Lying HOMO Levels as an Efficient Cathode Interlayer in Inverted Polymer Solar Cells.

    Science.gov (United States)

    Kan, Yuanyuan; Zhu, Yongxiang; Liu, Zhulin; Zhang, Lianjie; Chen, Junwu; Cao, Yong

    2015-08-01

    Two hydrophilic conjugated polymers, PmP-NOH and PmP36F-NOH, with polar diethanol-amine on the side chains and main chain structures of poly(meta-phenylene) and poly(meta-phenylene-alt-3,6-fluorene), respectively, are successfully synthesized. The films of PmP-NOH and PmP36F-NOH show absorption edges at 340 and 343 nm, respectively. The calculated optical bandgaps of the two polymers are 3.65 and 3.62 eV, respectively, the largest ones so far reported for hydrophilic conjugated polymers. PmP-NOH and PmP36F-NOH also possess deep-lying highest occupied molecular orbital levels of -6.19 and -6.15 eV, respectively. Inserting PmP-NOH and PmP36F-NOH as a cathode interlayer in inverted polymer solar cells with a PTB7/PC71 BM blend as the active layer, high power conversion efficiencies of 8.58% and 8.33%, respectively, are achieved, demonstrating that the two hydrophilic polymers are excellent interlayers for efficient inverted polymer solar cells. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Novel polyoxometalate silica nano-sized spheres: efficient catalysts for olefin oxidation and the deep desulfurization process.

    Science.gov (United States)

    Nogueira, Lucie S; Ribeiro, Susana; Granadeiro, Carlos M; Pereira, Eulália; Feio, Gabriel; Cunha-Silva, Luís; Balula, Salete S

    2014-07-07

    A novel method to prepare silica nano-sized particles incorporating polyoxometalates was developed leading to a new efficient heterogeneous oxidative catalyst. Zinc-substituted polyoxotungstate [PW11Zn(H2O)O39](5-) (PW11Zn) was encapsulated into silica nanoparticles using a cross-linked organic-inorganic core, performed through successive spontaneous reactions in water. The potassium salt of PW11Zn and the composite formed, PW11Zn-APTES@SiO2, were characterized by a myriad of solid-state methods such as FT-IR, FT-Raman, (31)P and (13)C CP/MAS solid-state NMR, elemental analysis and SEM-EDS, confirming the integrity of the PW11Zn structure immobilized in the silica nanoparticles. The new composite has shown to be a versatile catalyst for the oxidation of olefins and also to catalyze the desulfurization of a model oil using H2O2 as the oxidant and acetonitrile as the solvent. The novel composite material was capable of being recycled without significant loss of activity and maintaining its structural stability for consecutive desulfurization and olefin oxidative cycles.

  19. ASSESSMENT OF SELECTED PROPERTIES OF NORMAL CONCRETES WITH THE GRINDED RUBBER FROM WORN OUT VEHICLE TYRES

    Directory of Open Access Journals (Sweden)

    Ewa Ołdakowska

    2015-07-01

    Full Text Available Rubber from the worn tyres is associated with a useless material, strenuous for environment, whose most popular recovery method until recently was storage (currently forbidden by law. The adoption and dissemination of new ecological standards, created not only by the European and national legislation, but also developing as a result of expanding ecological consciousness, forces the necessity of seeking efficient methods of utilization of the vehicle tyres. The exemplary solution for the problem of tyres withdrawn from the operation, presented in the article, is using them in the grinded form as a substitute for the natural aggregate for the production of normal concrete. The article presents the results of the tests of selected properties of the modified normal concrete, upon the basis of which it has been found that the rubber causes decrease of compression strength, concrete weight, limits water absorbability, and does not influence significantly the physical and chemical phenomena accompanying the composite structure formation.

  20. A Review: The Effect of Grinded Coal Bottom Ash on Concrete

    Directory of Open Access Journals (Sweden)

    Basirun Nurul Fasihah

    2017-01-01

    Full Text Available This paper offers a review on the use of grinded coal bottom ash (CBA on the concrete properties as demonstrated by strength test and microstructure test. Amount of CBA from power plant station was disposed in landfill because of the particle shape had a rough particles. By finding an alternative way to gain its surface area by grinding and used as replacement material as cement replacement may give a good side feedback on the strength and morphology of concrete. Most of the prior works studied on the grinded fly ash and grinded rice husk ash. The study on the influence of grinded CBA on the properties of concrete still limited and need more attention Therefore, the review on the effect of grinded CBA on the strength and microstructure of concrete are discussed.

  1. A dynamic model of cylindrical plunge grinding process for chatter phenomena investigation

    Directory of Open Access Journals (Sweden)

    Lajmert Paweł

    2018-01-01

    Full Text Available In the paper, chatter vibrations in the cylindrical plunge grinding process are investigated. An improved model of the grinding process was developed which is able to simulate self-excited vibrations due to a regenerative effect on the workpiece and the grinding wheel surface. The model includes a finite-element model of the workpiece, two degrees of freedom model of the grinding wheel headstock and a model of wheel-workpiece geometrical interferences. The model allows to studying the influence of different factors, i.e. workpiece and machine parameters as well as grinding conditions on the stability limit and a chatter vibration growth rate. At the end, simulation results are shown and compared with exemplified real grinding results.

  2. Safety of stationary grinding machines - impact resistance of work zone enclosures.

    Science.gov (United States)

    Mewes, Detlef; Adler, Christian

    2017-09-01

    Guards on machine tools are intended to protect persons from being injured by parts ejected with high kinetic energy from the work zone of the machine. Stationary grinding machines are a typical example. Generally such machines are provided with abrasive product guards closely enveloping the grinding wheel. However, many machining tasks do not allow the use of abrasive product guards. In such cases, the work zone enclosure has to be dimensioned so that, in case of failure, grinding wheel fragments remain inside the machine's working zone. To obtain data for the dimensioning of work zone enclosures on stationary grinding machines, which must be operated without an abrasive product guard, burst tests were conducted with vitrified grinding wheels. The studies show that, contrary to widely held opinion, narrower grinding wheels can be more critical concerning the impact resistance than wider wheels although their fragment energy is smaller.

  3. Teeth grinding, oral motor performance and maximal bite force in cerebral palsy children.

    Science.gov (United States)

    Botti Rodrigues Santos, Maria Teresa; Duarte Ferreira, Maria Cristina; de Oliveira Guaré, Renata; Guimarães, Antonio Sergio; Lira Ortega, Adriana

    2015-01-01

    Identify whether the degree of oral motor performance is related to the presence of teeth grinding and maximal bite force values in children with spastic cerebral palsy. Ninety-five spastic cerebral palsy children with and without teeth grinding, according to caregivers' reports, were submitted to a comprehensive oral motor performance evaluation during the feeding process using the Oral Motor Assessment Scale. Maximal bite force was measured using an electronic gnathodynamometer. The teeth grinding group (n = 42) was younger, used anticonvulsant drugs, and was more frequently classified within the subfunctional oral motor performance category. Teeth grinding subfunctional spastic cerebral palsy children presented lower values of maximal bite force. The functional groups showing the presence or absence of teeth grinding presented higher values of maximal bite force compared with the subfunctional groups. In spastic cerebral palsy children, teeth grinding is associated with the worse oral motor performance. © 2015 Special Care Dentistry Association and Wiley Periodicals, Inc.

  4. Isoflavone profile in soymilk as affected by soybean variety, grinding, and heat-processing methods.

    Science.gov (United States)

    Zhang, Yan; Chang, Sam K C; Liu, Zhisheng

    2015-05-01

    Isoflavones impart health benefits and their overall content and profile in foods are greatly influenced at each step during processing. In this study, 2 soybean varieties (Prosoy and black soybean) were processed with 3 different grinding (ambient, cold, and hot grinding) and heating methods (traditional stove cooking, 1-phase UHT, and 2-phase UHT) for soymilk making. The results showed after cold, ambient, and hot grinding, the total isoflavones were 3917, 5013, and 5949 nmol/g for Prosoy; the total isoflavones were 4073, 3966, and 4284 nmol/g for black soybean. Grinding could significantly increase isoflavone extraction. The grinding process had a destructive effect on isoflavones and this effect varied with grinding temperature. Different heating methods had different effects on different isoflavone forms. Two soybean varieties showed distinct patterns with respect to the change of isoflavone profile during processing. © 2015 Institute of Food Technologists®

  5. Numerical and experimental hydrodynamic study of a coolant distributor for grinding applications

    Directory of Open Access Journals (Sweden)

    Tala Moussa

    2016-01-01

    Full Text Available In grinding, the high frictional energy is converted into heat, which may cause thermal damage and degradation of the wheel and the workpiece. Unwanted thermal effects must thus be reduced, often by external cooling using a curved-duct coolant distributor to match the wheel geometry. The performance of such a system depends strongly on the impinging jet flow properties to ensure efficient sprinkling of the hot spots. The fluid distributor, placed above the workpiece, is pierced with a certain number of identical nozzle fittings, providing multiple jets at the outlet of the nozzles. These jets sprinkle the solids over a given zone and remove the heat by convective transfer. The cooling is hence dependent on the flow structure, meaning the jet diameters, trajectories and velocities, determined up-flow by the distributor design. The present study is devoted to the hydrodynamics aspects of the fluid distributor, aiming to determine the flow-rate distribution at the different orifices and the flow-rate–pressure relationship, for a variety of nozzle diameters and feeding flow rates, under isothermal conditions. A simple hydraulic balance in the device was not able to predict with sufficient accuracy the actual measurements, even when the Venturi effect was accounted for. This discrepancy is due to the curvature of the distributor, inducing secondary flows in interaction with the nozzle outlets, which leads to a rather complex flow pattern. To overcome this issue, a computational fluid dynamics (CFD tool was used and compared with in situ experiments – global flow rate and pressure measurements were additionally taken with particle image velocimetry (PIV to gain insight into the local structure. Simulations were performed with a 3D turbulence model for Reynolds numbers up to 100,000. This model provides an efficient tool for coupling with the thermal study at a later step, allowing global sizing and energetic optimization of the grinding process.

  6. Comparison of different grinding procedures on the flexural strength of zirconia.

    Science.gov (United States)

    Işeri, Ufuk; Ozkurt, Zeynep; Yalnız, Ayşe; Kazazoğlu, Ender

    2012-05-01

    The surface of zirconia ceramic is damaged during grinding, which may affect the mechanical properties of the material. The purpose of this study was to compare the biaxial flexural strength of zirconia after different grinding procedures and to measure the temperature rise from grinding. Forty disk-shaped zirconia specimens (15 × 1.2 mm) with a smaller disk in the center of each disk (1 × 3 mm) were divided into 4 groups (n=10). The specimens were ground with a high-speed handpiece and micromotor with 2 different grinding protocols, continual grinding and periodic grinding (10 seconds grinding with 10 seconds duration), until the smaller disk was removed. Control specimens without the center disk (n=10) were analyzed without grinding. The biaxial flexural strengths of the disks were determined in a universal testing machine at a crosshead speed of 0.5 mm/min. The fracture strength (MPa) was recorded, and the results were analyzed using a 1-way ANOVA, Tukey HSD test, Student's t test, and Pearson correlation test (α=05). All grinding procedures significantly decreased flexural strength (Pmicromotor groups (718 MPa). The temperature values obtained from micromotor grinding (127°C) were significantly higher than those from high-speed handpiece grinding (63°C) (P<.01). Grinding zirconia decreased flexural strength. Zirconia material ground with a high-speed handpiece run continually caused the least reduction in flexural strength. Copyright © 2012 The Editorial Council of the Journal of Prosthetic Dentistry. Published by Mosby, Inc. All rights reserved.

  7. MODELING AND OPTIMIZATION OF CYLINDRICAL GRINDING PARAMETERS FOR MRR AND SURFACE ROUGHNESS

    OpenAIRE

    Kshitij R Patil1, Rupesh J Karande2, Dadaso D. Mohite3, Vishwas S Jadhav4

    2017-01-01

    Cylindrical grinding is one of the important metal cutting processes used extensively in the finishing operations. The grinding process plays an important role in every manufacturing activity. The surface properties can be altered by changing various grinding parameters in order to achieve best surface finish resulting in low surface roughness value and with possible maximum metal removal rate. Four parameters, namely spindle speed, feed rate, depth of cut and hardness of material were identi...

  8. Investigation of the Formation Process of Two Piracetam Cocrystals during Grinding

    OpenAIRE

    Rehder, Sönke; Klukkert, Marten; Löbmann, Korbinian A. M.; Strachan, Clare J.; Sakmann, Albrecht; Gordon, Keith; Rades, Thomas; Leopold, Claudia S.

    2011-01-01

    Cocrystal formation rates during dry grinding and liquid-assisted grinding were investigated by X-ray powder diffractometry and Raman spectroscopy. Two polymorphic forms of piracetam were used to prepare known piracetam cocrystals as model substances, i.e., piracetam-citric acid and piracetam-tartaric acid cocrystals. Raman spectroscopy in combination with principal component analysis was used to visualize the cocrystal formation pathways. During dry grinding, cocrystal formation appeared to ...

  9. Axisymmetric alternating direction explicit scheme for efficient coupled simulation of hydro-mechanical interaction in geotechnical engineering—Application to circular footing and deep tunnel in saturated ground

    Directory of Open Access Journals (Sweden)

    Simon Heru Prassetyo

    2018-04-01

    Full Text Available Explicit solution techniques have been widely used in geotechnical engineering for simulating the coupled hydro-mechanical (H-M interaction of fluid flow and deformation induced by structures built above and under saturated ground, i.e. circular footing and deep tunnel. However, the technique is only conditionally stable and requires small time steps, portending its inefficiency for simulating large-scale H-M problems. To improve its efficiency, the unconditionally stable alternating direction explicit (ADE scheme could be used to solve the flow problem. The standard ADE scheme, however, is only moderately accurate and is restricted to uniform grids and plane strain flow conditions. This paper aims to remove these drawbacks by developing a novel high-order ADE scheme capable of solving flow problems in non-uniform grids and under axisymmetric conditions. The new scheme is derived by performing a fourth-order finite difference (FD approximation to the spatial derivatives of the axisymmetric fluid–diffusion equation in a non-uniform grid configuration. The implicit Crank-Nicolson technique is then applied to the resulting approximation, and the subsequent equation is split into two alternating direction sweeps, giving rise to a new axisymmetric ADE scheme. The pore pressure solutions from the new scheme are then sequentially coupled with an existing geomechanical simulator in the computer code fast Lagrangian analysis of continua (FLAC. This coupling procedure is called the sequentially-explicit coupling technique based on the fourth-order axisymmetric ADE scheme or SEA-4-AXI. Application of SEA-4-AXI for solving axisymmetric consolidation of a circular footing and of advancing tunnel in deep saturated ground shows that SEA-4-AXI reduces computer runtime up to 42%–50% that of FLAC's basic scheme without numerical instability. In addition, it produces high numerical accuracy of the H-M solutions with average percentage difference of only 0.5%

  10. Interproximal grinding (disking) of caries in primary molars, attitudes and the extent utilized in a Swedish County.

    Science.gov (United States)

    Granath, Johanna; Asztély, Anna; Lundgren, Ted

    2018-04-30

    To assess the occurrence of interproximal grinding as a caries therapy in primary molars, to what degree grinding replaced conventional restorative caries therapy, to what extent anaesthesia was used while grinding and to assess open comments about attitudes about grinding. A questionnaire was sent to 108 public dental service clinics with questions concerning the use of grinding as a therapy and alternative to restorative treatment, the use of anaesthesia prior to conventional caries therapy and grinding, respectively. In addition, a content analysis of open comments about grinding was performed. Grinding had been performed in 96% of the clinics. Two-thirds of the dentists used grinding as an alternative to conventional restorative treatment at some point. Most dentists used anaesthesia prior to restorative therapy. Prior to grinding, the frequency of anaesthesia was lower (median 5.0) than for conventional restorative therapy (median 8.7) (p grinding. Grinding has been widely practiced in parts of Sweden, is presently a technique employed by a multitude of dentists, and that anaesthesia is used less frequently prior to grinding, in comparison to conventional restorative therapy. Dentist considered grinding as a treatment option in specific situations.

  11. TL sensitivity of CaSO4:Dy phosphor powder - effect of grinding

    International Nuclear Information System (INIS)

    Shastry, S.S.; Kher, R.K.

    1979-01-01

    Grinding of polycrystalline CaSO 4 :Dy phosphor to powder form induces lattice defects. Changes in thermoluminescence (TL) sensitivity due to variation in trap density in the bulk and on the surface of phosphor grains are studied using gamma and UV radiations. TL sensitivity to gamma increases with grinding time due to the contribution from the new bulk traps which are generated by grinding. The surface traps degrade with increase in grinding time resulting in a decrease in UV sensitivity. Results on regeneration of the TL sensitivity due to annealing at different temperatures are also included. (Auth.)

  12. Lab-scale roller table mill for investigating the grinding behaviour of coal

    Energy Technology Data Exchange (ETDEWEB)

    Werner, V.; Zelkowski, J.; Schoenert, K. [Inst. for Energy Process Engineering and Fuel Technology and Inst. of Mineral Processing, Univ. Clausthal, Clausthal-Zellerfeld (Germany)

    1999-11-01

    The test mill is equipped with one roller. The material bed can be discharged completely after overroling. Grinding force, torque and gap width are measured. Cycle tests with three coals have been performed for simulating a closed circuit process. The grinding behaviour is characterized by the following relations: compaction of the particle bed and specific power draft vs. specific grinding force, production of fine material (dust), circuit factor, specific surface of the dust and specific work-input of the grinding circuit vs. specific power draft. (orig.)

  13. Experimental and Numerical Investigations in Shallow Cut Grinding by Workpiece Integrated Infrared Thermopile Array.

    Science.gov (United States)

    Reimers, Marcel; Lang, Walter; Dumstorff, Gerrit

    2017-09-30

    The purpose of our study is to investigate the heat distribution and the occurring temperatures during grinding. Therefore, we did both experimental and numerical investigations. In the first part, we present the integration of an infrared thermopile array in a steel workpiece. Experiments are done by acquiring data from the thermopile array during grinding of a groove in a workpiece made of steel. In the second part, we present numerical investigations in the grinding process to further understand the thermal characteristic during grinding. Finally, we conclude our work. Increasing the feed speed leads to two things: higher heat flux densities in the workpiece and higher temperature gradients in the material.

  14. Association between anticonvulsant drugs and teeth-grinding in children and adolescents with cerebral palsy.

    Science.gov (United States)

    Ortega, A O L; Dos Santos, M T B R; Mendes, F M; Ciamponi, A L

    2014-09-01

    The relation between teeth-grinding and the use of drugs acting on the central nervous system of cerebral palsy (CP) patients has not yet been described. The aim of this research was to evaluate the presence or absence of teeth-grinding (sleep and/or awake periods) in normal and in CP children and adolescents, as well as the association of teeth-grinding and use of anticonvulsant drugs. The sample consisted of 207 children and adolescents, divided into three groups: G1, individuals with CP who did not take anticonvulsant drugs; G2, individuals with CP administered medications on a regular basis; and CG, normal individuals. Logistic regression analyses were performed to evaluate the association of teeth-grinding with some variables. No significant statistical differences were observed regarding the presence or absence of teeth-grinding when G1 and G2 were compared. However, compared with the CG, a statistically significant difference was determined, with the CG showing fewer children presenting teeth-grinding (P grinding. CP children and adolescents show a greater and significant presence of grinding of the teeth compared with normal individuals. Subjects taking barbiturate drugs showed greater presence of teeth-grinding, than those who were taking medications from the other groups of anticonvulsant drugs. © 2014 John Wiley & Sons Ltd.

  15. ANALYSIS OF THE SURFACE PROFILE AND ITS MATERIAL SHARE DURING THE GRINDING INCONEL 718 ALLOY

    Directory of Open Access Journals (Sweden)

    Martin Novák

    2015-05-01

    Full Text Available Grinding is still an important method for surface finishing. At FPTM JEPU research, which deals with this issue is conducted. Experiments are carried out with grinding various materials under different conditions and then selected components of the surface integrity are evaluated. They include roughness Ra, Rm and Rz, Material ratio curve (Abbott Firestone curve and also the obtained roundness. This article deals with grinding nickel Inconel 718 alloy, when selected cutting grinding conditions were used and subsequently the surface profile and the material ratio curve were measured and evaluated.

  16. Experimental and Numerical Investigations in Shallow Cut Grinding by Workpiece Integrated Infrared Thermopile Array

    Directory of Open Access Journals (Sweden)

    Marcel Reimers

    2017-09-01

    Full Text Available The purpose of our study is to investigate the heat distribution and the occurring temperatures during grinding. Therefore, we did both experimental and numerical investigations. In the first part, we present the integration of an infrared thermopile array in a steel workpiece. Experiments are done by acquiring data from the thermopile array during grinding of a groove in a workpiece made of steel. In the second part, we present numerical investigations in the grinding process to further understand the thermal characteristic during grinding. Finally, we conclude our work. Increasing the feed speed leads to two things: higher heat flux densities in the workpiece and higher temperature gradients in the material.

  17. Imaging subsurface damage of grinded fused silica optics by confocal fluorescence microscopy

    International Nuclear Information System (INIS)

    Neauport, J.; Cormont, P.; Destribats, J.; Legros, P.; Ambard, C.

    2009-01-01

    We report an experimental investigation of fluorescence confocal microscopy as a tool to measure subsurface damage on grinded fused silica optics. Confocal fluorescence microscopy was performed with an excitation at the wavelength of 405 nm on fixed abrasive diamond grinded fused silica samples. We detail the measured fluorescence spectrums and compare them to those of oil based coolants and grinding slurries. We evidence that oil based coolant used in diamond grinding induces a fluorescence that marks the subsurface damages and eases its observation. Such residual traces might also be involved in the laser damage process. (authors)

  18. Grinding and polishing of conformal windows and domes

    Science.gov (United States)

    Fess, Edward; Ross, James; Matthews, Greg

    2017-05-01

    Conformal optics require special manufacturing techniques to produce them to optical tolerances. In many cases the materials used are very hard optical ceramics that present additional manufacturing challenges due to their hardness and grain structure. OptiPro has developed grinding technologies such as OptiSonic grinding, as well as sub-aperture polishing technologies like UltraForm Finishing (UFF) to manufacture these challenging components. We have also developed a custom computer aided manufacturing (CAM) software package, ProSurf, to generate the complex tool paths for both grinding and polishing processes. One of the main advantages of ProSurf over traditional CAM software packages is that it uses metrology feedback for deterministic corrections. The metrology input can be obtained from OptiPro's 5-axis UltraSurf metrology system, which is capable of measuring these complex shapes to sub-micron accuracies. Through the development of these technologies much work has been performed in creating, measuring and analyzing the alignment fiducials or datum's used to qualify the location of the optical surfaces. Understanding the sensitivity of the optical surface to any datum misalignment is critical to knowing not only where the part is in space, but how good the optical surfaces are to each other. Working with the optical designer to properly tolerance surfaces to these datums is crucial. This paper will present the technologies developed by OptiPro to manufacture conformal windows as well as information related to the optical surfaces sensitivity to datums and how accurately those datums can be measured.

  19. Dissolution enhancement of atorvastatin calcium by co-grinding technique.

    Science.gov (United States)

    Prabhu, Priyanka; Patravale, Vandana

    2016-08-01

    Atorvastatin calcium (AC) is a BCS class II drug which shows poor bioavailability due to inadequate dissolution. Solid dispersions present a promising option to enhance the solubility of poorly soluble drugs. Co-grinding with hydrophilic excipients is an easy and economical technique to improve the solubility of poorly soluble drugs and is free from usage of organic solvents. The aim of the present study was to explore novel carrier VBP-1 (organosulphur compound) for formulating a solid dispersion by using a simple, commercially viable co-grinding technique to enhance the dissolution of AC and to develop an oral formulation of the same. Composition of the solid dispersion was optimized based on the release profile in pH 1.2 buffer. The optimized solid dispersion was further characterized for flow properties, DSC, FTIR spectroscopy, XRD, contact angle, SEM studies and release profile in phosphate buffer pH 6.8. The developed solid dispersion gave similar release profile as the innovator formulation (Lipitor® tablets) in both pH 1.2 buffer and phosphate buffer pH 6.8. The developed solid dispersion was formulated into hard gelatin capsules (size 3). The developed capsules were found to give similar release as the innovator formulation in both pH 1.2 buffer and phosphate buffer pH 6.8. The developed capsules were found to be stable for a period of 6 months. Anti-hyperlipidemic efficacy studies in rats showed higher reduction in cholesterol and triglyceride levels by the developed capsules in comparison to pure AC. In conclusion, novel carrier VBP-1 was successfully employed to enhance the dissolution of AC using co-grinding technique.

  20. Application of cryogenic grinding to achieve homogenization of transuranic wastes

    International Nuclear Information System (INIS)

    Atkins, W.H.; Hill, D.D.; Lucero, M.E.; Jaramillo, L.; Martinez, H.E.

    1996-08-01

    This paper describes work done at Los Alamos National Laboratory (LANL) in collaboration with the Department of Energy Rocky Flats Field Office (DOE/RFFO) and with the National Institute of Standards and Technology (NIST), Boulder, Colorado. Researchers on this project have developed a method for cryogenic grinding of mixed wastes to homogenize and, thereby, to acquire a representative sample of the materials. There are approximately 220,000 waste drums owned by the Rocky Flats Environmental Technology Site (RFETS)-50,000 at RFETS and 170,000 at the Idaho National Engineering Laboratory. The cost of sampling the heterogeneous distribution of waste in each drum is prohibitive. In an attempt to produce a homogeneous mixture of waste that would reduce greatly the cost of sampling, researchers at NIST and RFETS are developing a cryogenic grinder. The Los Alamos work herein described addresses the implementation issues of the task. The first issue was to ascertain whether samples of the open-quotes small particleclose quotes mixtures of materials present in the waste drums at RFETS were representative of actual drum contents. Second, it was necessary to determine at what temperature the grinding operation must be performed in order to minimize or to eliminate the release of volatile organic compounds present in the waste. Last, it was essential to evaluate any effect the liquid cryogen might have on the structural integrity and ventilation capacity of the glovebox system. Results of this study showed that representative samples could be and had been obtained, that some release of organics occurred below freezing because of sublimation, and that operation of the cryogenic grinding equipment inside the glovebox was feasible

  1. Grinding temperature and energy ratio coefficient in MQL grinding of high-temperature nickel-base alloy by using different vegetable oils as base oil

    OpenAIRE

    Li Benkai; Li Changhe; Zhang Yanbin; Wang Yaogang; Jia Dongzhou; Yang Min

    2016-01-01

    Vegetable oil can be used as a base oil in minimal quantity of lubrication (MQL). This study compared the performances of MQL grinding by using castor oil, soybean oil, rapeseed oil, corn oil, sunflower oil, peanut oil, and palm oil as base oils. A K-P36 numerical-control precision surface grinder was used to perform plain grinding on a workpiece material with a high-temperature nickel base alloy. A YDM–III 99 three-dimensional dynamometer was used to measure grinding force, and a clip-type t...

  2. Corrosion of Cast Iron Mill Plates in Wet Grinding

    Directory of Open Access Journals (Sweden)

    Anthony ANDREWS

    2010-12-01

    Full Text Available Corrosion studies were carried out on two different maize grinding plates. Maize was soaked in water for three days and the water decanted and used as electrolyte. Mass loss and pH measurements were carried out every 3 days for 15-day period. Results show that, for each plate, mass loss and pH increased with exposure time. Corrosion rates determined from mass loss data was found to be strongly dependent on pH. The observed behaviour may be explained in terms of the chemical composition and/or microstructures of the plates. Results are briefly discussed in terms of the contribution of corrosion to wear.

  3. Sealing efficiency of an argillite-bentonite plug subjected to gas pressure, in the context of deep underground nuclear waste storage

    International Nuclear Information System (INIS)

    Liu, Jiang-Feng

    2013-01-01

    In France, the deep underground nuclear waste repository consists of a natural barrier (in an argillaceous rock named argillite), associated to artificial barriers, including plugs of swelling clay (bentonite)-sand for tunnel sealing purposes. The main objective of this thesis is to assess the sealing efficiency of the bentonite-sand plug in contact with argillite, in presence of both water and gas pressures. To assess the sealing ability of partially water-saturated bentonite/sand plugs, their gas permeability is measured under varying confining pressure (up to 12 MPa). It is observed that tightness to gas is achieved under confinement greater than 9 MPa for saturation levels of at least 86-91%. We than assess the sealing efficiency of the bentonite-sand plug placed in a tube of argillite or of Plexiglas-aluminium (with a smooth or a rough interface). The presence of pressurized gas affects the effective swelling pressure at values P gas from 4 MPa. Continuous gas breakthrough of fully water-saturated bentonite-sand plugs is obtained for gas pressures on the order of full swelling pressure (7-8 MPa), whenever the plug is applied along a smooth interface. Whenever a rough interface is used in contact with the bentonite-sand plug, a gas pressure significantly greater than its swelling pressure is needed for gas to pass continuously. Gas breakthrough tests show that the interface between plug/argillite or the argillite itself are two preferential pathways for gas migration, when the assembly is fully saturated. (author)

  4. Microstructural and reliability in grinding of silicon nitride

    International Nuclear Information System (INIS)

    Liu, C.-C.

    2004-01-01

    A sintered Si 3 N 4 matrix has been characterized by TEM. The film thickness distribution of Si 3 N 4 was measured by high resolution transmission electron microscopy (HREM). Surface grinding is performed on two table speeds of 0.08 and 0.25 m s -1 with different depth of cut. The ground surfaces were observed with scanning electron microscopy (SEM). The surface texture was found to have greater dependence on depth of cut and table speed. The surface roughness is improved after smaller depth of cut. The flexural strength of ground specimens were measured by four-point flexure tests. The effect of depth of cut during grinding on the flexural strength and reliability of silicon nitride is investigated. The large depth of cut of 30 μm/pass resulted in a further decreased in strength of 540 MPa and a Weibull modulus of 7.5. When the depth of cut of 5 μm/pass were subjected to the ground specimens, the average strength was increased to 670 MPa and Weibull modulus to 9.1

  5. Diamond blade grinding as a means for removing surface contamination from concrete

    International Nuclear Information System (INIS)

    Lynch, T.W.

    1980-01-01

    The use of a highway grinding unit for the decontamination of a 5,000 square foot surface is described. The type of equipment presently in use is described. Performance characteristics, waste collection and water usage are commented on. Variables in blade design are discussed. Feasibility of the grinding technique for water soluble contaminants and vertical surfaces is referred to

  6. Controlled wear of vitrified abrasive materials for precision grinding ...

    Indian Academy of Sciences (India)

    The study of bonding hard materials such as aluminium oxide and cubic boron nitride (BN) and the nature of interfacial cohesion between these materials and glass is very important from the perspective of high precision grinding. Vitrified grinding wheels are typically used to remove large volumes of metal and to produce ...

  7. Recognition of diamond grains on surface of fine diamond grinding wheel

    Institute of Scientific and Technical Information of China (English)

    Fengwei HUO; Zhuji JIN; Renke KANG; Dongming GUO; Chun YANG

    2008-01-01

    The accurate evaluation of grinding wheel sur-face topography, which is necessary for the investigation of the grinding principle, optimism, modeling, and simu-lation of a grinding process, significantly depends on the accurate recognition of abrasive grains from the measured wheel surface. A detailed analysis of the grain size distri-bution characteristics and grain profile wavelength of the fine diamond grinding wheel used for ultra-precision grinding is presented. The requirements of the spatial sampling interval and sampling area for instruments to measure the surface topography of a diamond grinding wheel are discussed. To recognize diamond grains, digital filtering is used to eliminate the high frequency disturb-ance from the measured 3D digital surface of the grinding wheel, the geometric features of diamond grains are then extracted from the filtered 3D digital surface, and a method based on the grain profile frequency characteris-tics, diamond grain curvature, and distance between two adjacent diamond grains is proposed. A 3D surface pro-filer based on scanning white light interferometry is used to measure the 3D surface topography of a #3000 mesh resin bonded diamond grinding wheel, and the diamond grains are then recognized from the 3D digital surface. The experimental result shows that the proposed method is reasonable and effective.

  8. Complete Chiral Resolution Using Additive-Induced Crystal Size Bifurcation During Grinding

    NARCIS (Netherlands)

    Noorduin, Wim L.; Asdonk, Pim van der; Meekes, Hugo; Enckevort, Willem J.P. van; Kaptein, Bernard; Leeman, Michel; Kellogg, Richard M.; Vlieg, Elias

    2009-01-01

    Grinding them down: By using a tailor-made additive, even in the absence of racemization in solution, abrasive grinding can yield an enantiopure solid state. This novel chiral resolution technique is based on an asymmetric bifurcation in the crystal size distribution as a result of stereoselective

  9. Thermal model to investigate the temperature in bone grinding for skull base neurosurgery.

    Science.gov (United States)

    Zhang, Lihui; Tai, Bruce L; Wang, Guangjun; Zhang, Kuibang; Sullivan, Stephen; Shih, Albert J

    2013-10-01

    This study develops a thermal model utilizing the inverse heat transfer method (IHTM) to investigate the bone grinding temperature created by a spherical diamond tool used for skull base neurosurgery. Bone grinding is a critical procedure in the expanded endonasal approach to remove the cranial bone and access to the skull base tumor via nasal corridor. The heat is generated during grinding and could damage the nerve or coagulate the blood in the carotid artery adjacent to the bone. The finite element analysis is adopted to investigate the grinding-induced bone temperature rise. The heat source distribution is defined by the thermal model, and the temperature distribution is solved using the IHTM with experimental inputs. Grinding experiments were conducted on a bovine cortical bone with embedded thermocouples. Results show significant temperature rise in bone grinding. Using 50°C as the threshold, the thermal injury can propagate about 3mm in the traverse direction, and 3mm below the ground surface under the dry grinding condition. The presented methodology demonstrated the capability of being a thermal analysis tool for bone grinding study. Copyright © 2013 IPEM. Published by Elsevier Ltd. All rights reserved.

  10. The effect of grinding on magnetic properties of agglomereted MnFe2O4 nanoparticles

    International Nuclear Information System (INIS)

    Aslibeiki, B.; Kameli, P.; Salamati, H.

    2012-01-01

    The effects of grinding on interparticle magnetic interactions for an ensemble of agglomerated MnFe 2 O 4 nanoparticles have been studied. Structural analyses showed that by grinding the samples, a small variation in size of crystallites and lattice strain will occur. ac Magnetic susceptibility measurements under different conditions and spin dynamics analysis suggest that freezing temperature is frequency dependent and it is in good agreement with critical slowing down model. This is an indication that these nanoparticles have superspin glass behavior. The estimated zυ and τ 0 parameters using critical slowing down model show that by increasing the grinding time the interaction between nanoparticles decreases. ac Susceptibility measurements in cooling and heating process show a thermal hysteresis. The thermal hysteresis decreased by increasing the grinding time. Also, the thermal hysteresis is frequency dependent and it increased as frequency decreased. These results showed that interparticle interactions such as dipole-dipole and exchange interactions between nanoparticles become weaker by grinding. - Highlights: → We studied the effects of grinding on interparticle interactions of MnFe 2 O 4 nanoparticles. → Critical slowing model used to estimate the interparticle interaction strength. → The results showed interparticle interactions become weaker by grinding. → Ac Susceptibility shows the irreversibility of spins decreased by grinding.

  11. Effect of Grinding on the Solid-State Stability and Particle Dissolution of Acyclovir Polymorphs.

    Science.gov (United States)

    Magnoni, Federico; Gigliobianco, Maria Rosa; Vargas Peregrina, Dolores; Censi, Roberta; Di Martino, Piera

    2017-10-01

    The present work investigated the solid state change of 4 acyclovir polymorphs when ground at room temperature (Method A) and under cryo-grinding in the presence of liquid nitrogen (Method B). Modifications in particle size and shape (evaluated by scanning electron microscopy) and in the water content (evaluated by thermal analysis) were related to transitions at the solid state, as confirmed by X-ray powder diffractometry. Anhydrous Form I was stable under grinding by both Methods A and B. The anhydrous Form II was stable during grinding under Method A, whereas it was progressively converted to the hydrate Form V during grinding under Method B. The hydrate Form V was stable under Method A, whereas it was converted to the anhydrous Form I after 15 min and then to the hydrate Form VI after 45 min of grinding. The hydrate Form VI proved to be stable under grinding by both Methods A and B. Thus, Form I and VI were the only forms that yielded a sizeable decrease in particle size under grinding, with a consequent increase in particle dissolution rate, while maintaining solid state physicochemical stability. Form I treated under Method B grinding gave the best dissolution rate. Copyright © 2017 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

  12. Mechanism and experimental research on ultra-precision grinding of ferrite

    Science.gov (United States)

    Ban, Xinxing; Zhao, Huiying; Dong, Longchao; Zhu, Xueliang; Zhang, Chupeng; Gu, Yawen

    2017-02-01

    Ultra-precision grinding of ferrite is conducted to investigate the removal mechanism. Effect of the accuracy of machine tool key components on grinding surface quality is analyzed. The surface generation model of ferrite ultra-precision grinding machining is established. In order to reveal the surface formation mechanism of ferrite in the process of ultraprecision grinding, furthermore, the scientific and accurate of the calculation model are taken into account to verify the grinding surface roughness, which is proposed. Orthogonal experiment is designed using the high precision aerostatic turntable and aerostatic spindle for ferrite which is a typical hard brittle materials. Based on the experimental results, the influence factors and laws of ultra-precision grinding surface of ferrite are discussed through the analysis of the surface roughness. The results show that the quality of ferrite grinding surface is the optimal parameters, when the wheel speed of 20000r/mm, feed rate of 10mm/min, grinding depth of 0.005mm, and turntable rotary speed of 5r/min, the surface roughness Ra can up to 75nm.

  13. Nano finish grinding of brittle materials using electrolytic in-process ...

    Indian Academy of Sciences (India)

    2016-08-26

    Aug 26, 2016 ... Recent developments in grinding have opened up new avenues for finishing of hard and brittle materials with nano-surface finish, high tolerance and accuracy. Grinding with superabrasive wheels is an excellent way to produce ultraprecision surface finish. However, superabrasive diamond grits need ...

  14. Comminution efficiency attracts attention

    International Nuclear Information System (INIS)

    Daniel, M.J.; Lewis-Gray, E.

    2011-01-01

    The mining sector, both at a technical and board level is pursuing opportunities to achieve cost savings and reduce energy usage in their operations. Research and debate on step change efficiency benefits is particularly evident in the field of comminution (crushing and grinding) circuit design and operation. Published literature that quantifies mining related energy consumption in South Africa and Australia has been reviewed by the authors.

  15. Analysis of process parameters in surface grinding using single objective Taguchi and multi-objective grey relational grade

    Directory of Open Access Journals (Sweden)

    Prashant J. Patil

    2016-09-01

    Full Text Available Close tolerance and good surface finish are achieved by means of grinding process. This study was carried out for multi-objective optimization of MQL grinding process parameters. Water based Al2O3 and CuO nanofluids of various concentrations are used as lubricant for MQL system. Grinding experiments were carried out on instrumented surface grinding machine. For experimentation purpose Taguchi's method was used. Important process parameters that affect the G ratio and surface finish in MQL grinding are depth of cut, type of lubricant, feed rate, grinding wheel speed, coolant flow rate, and nanoparticle size. Grinding performance was calculated by the measurement G ratio and surface finish. For improvement of grinding process a multi-objective process parameter optimization is performed by use of Taguchi based grey relational analysis. To identify most significant factor of process analysis of variance (ANOVA has been used.

  16. Preparation of Grinding Aid Using Waste Acid Residue from Plasticizer Plant

    Science.gov (United States)

    Li, Lingxiao; Feng, Yanchao; Liu, Manchao; Zhao, Fengqing

    2017-09-01

    The grinding aid for granulated blast-furnace slag were prepared from waste acid residue from plasticizer plant through neutralization, de-methanol and granulation process. In this process, sulfuric acid was transformed into gypsum which has much contribution for grinding effect by combined use with the glycerol and poly glycerin in the waste. Fly ash was used for granulation for the composite grinding aid. Methanol can be recycled in the process. The result showed that the suitable addition of grinding aid is 0.03 % of granulated blast-furnace slag (mass). In this case, the specific surface area is 14% higher than that of the blank. Compared with the common grinding aids, it has excellent performance and low cost.

  17. Investigation of the formation process of two piracetam cocrystals during grinding

    DEFF Research Database (Denmark)

    Rehder, Sönke; Klukkert, Marten; Löbmann, Korbinian

    2011-01-01

    Cocrystal formation rates during dry grinding and liquid-assisted grinding were investigated by X-ray powder diffractometry and Raman spectroscopy. Two polymorphic forms of piracetam were used to prepare known piracetam cocrystals as model substances, i.e.,piracetam-citric acid and piracetam......-tartaric acid cocrystals. Raman spectroscopy in combination with principal component analysis was used to visualize the cocrystal formation pathways. During dry grinding, cocrystal formation appeared to progress via an amorphous intermediate stage, which was more evident for the piracetam-citric acid than...... for the piracetam-tartaric acid cocrystal. It was shown that liquid-assisted grinding led to faster cocrystal formation than dry grinding, which may be explained by the higher transformation rate due to the presence of liquid. The cocrystal formation rate did not depend on the applied polymorphic form...

  18. Surface crack formation on rails at grinding induced martensite white etching layers

    DEFF Research Database (Denmark)

    Rasmussen, Carsten Jørn; Fæster, Søren; Dhar, Somrita

    2017-01-01

    The connection between profile grinding of rails, martensite surface layers and crack initiation has been investigated using visual inspection, optical microscopy and 3D X-ray computerized tomography. Newly grinded rails were extracted and found to be covered by a continuous surface layer...... of martensite with varying thickness formed by the grinding process. Worn R350HT and R200 rails were extracted from the Danish rail network as they had transverse bands resembling grinding marks on the running surface. The transverse bands were shown to consist of martensite which had extensive crack formation...... at the martensite/pearlite interface. The cracks in R350HT propagated down into the rail while those in the soft R200 returned to the surface causing only very small shallow spallation. The transverse bands had the same shape, size, orientation, location and periodicity which would be expected from grinding marks...

  19. Grinding patterns in migraine patients with sleep bruxism: a case-controlled study.

    Science.gov (United States)

    Kato, Momoko; Saruta, Juri; Takeuchi, Mifumi; Sugimoto, Masahiro; Kamata, Yohei; Shimizu, Tomoko; To, Masahiro; Fuchida, Shinya; Igarashi, Hisaka; Kawata, Toshitsugu; Tsukinoki, Keiichi

    2016-11-01

    Details on grinding patterns and types of contact during sleep bruxism in association with migraine headache have not yet been elucidated. This study compared the characteristics of sleep bruxism between patients with migraine and controls. The study included 80 female patients who had been diagnosed with migraine and 52 women with no history of migraine. Grinding patterns were measured using the BruxChecker® (Scheu Dental, Iserlohn, Germany). There was a significant difference between the two groups in the distribution of grinding patterns at the laterotrusive side (p grinding area at all sites was significantly larger in the migraine group than in the control group (p grinding over a large area among migraine patients, particularly in the molar region.

  20. Investigation of the Formation Process of Two Piracetam Cocrystals during Grinding

    Science.gov (United States)

    Rehder, Sönke; Klukkert, Marten; Löbmann, Korbinian A. M.; Strachan, Clare J.; Sakmann, Albrecht; Gordon, Keith; Rades, Thomas; Leopold, Claudia S.

    2011-01-01

    Cocrystal formation rates during dry grinding and liquid-assisted grinding were investigated by X-ray powder diffractometry and Raman spectroscopy. Two polymorphic forms of piracetam were used to prepare known piracetam cocrystals as model substances, i.e., piracetam-citric acid and piracetam-tartaric acid cocrystals. Raman spectroscopy in combination with principal component analysis was used to visualize the cocrystal formation pathways. During dry grinding, cocrystal formation appeared to progress via an amorphous intermediate stage, which was more evident for the piracetam-citric acid than for the piracetam-tartaric acid cocrystal. It was shown that liquid-assisted grinding led to faster cocrystal formation than dry grinding, which may be explained by the higher transformation rate due to the presence of liquid. The cocrystal formation rate did not depend on the applied polymorphic form of the piracetam and no polymorphic cocrystals were obtained. PMID:24309304

  1. Investigation of the Formation Process of Two Piracetam Cocrystals during Grinding

    Directory of Open Access Journals (Sweden)

    Keith Gordon

    2011-10-01

    Full Text Available Cocrystal formation rates during dry grinding and liquid-assisted grinding were investigated by X-ray powder diffractometry and Raman spectroscopy. Two polymorphic forms of piracetam were used to prepare known piracetam cocrystals as model substances, i.e.,piracetam-citric acid and piracetam-tartaric acid cocrystals. Raman spectroscopy in combination with principal component analysis was used to visualize the cocrystal formation pathways. During dry grinding, cocrystal formation appeared to progress via an amorphous intermediate stage, which was more evident for the piracetam-citric acid than for the piracetam-tartaric acid cocrystal. It was shown that liquid-assisted grinding led to faster cocrystal formation than dry grinding, which may be explained by the higher transformation rate due to the presence of liquid. The cocrystal formation rate did not depend on the applied polymorphic form of the piracetam and no polymorphic cocrystals were obtained.

  2. Effect of simulated chairside grinding procedures using commercially available abrasive agents on the surface properties of zirconia

    OpenAIRE

    Sandhu, Ramandeep; Kheur, Mohit; Kheur, Supriya

    2017-01-01

    Aim: The aim of the present study was to assess the change in physical properties (surface roughness, surface hardness and phase transformation) after surface grinding of zirconia by using three commercially available abrasives. Materials and Methods: Thirty sintered zirconia specimens were prepared and divided into three groups namely Group M (grinded using Mani Dia diamond bur standard grit), Group T (grinded using Tri Hawk diamond bur coarse grit) and Group P (grinded using Predator car...

  3. Optimization of the dressing parameters in cylindrical grinding based on a generalized utility function

    Science.gov (United States)

    Aleksandrova, Irina

    2016-01-01

    The existing studies, concerning the dressing process, focus on the major influence of the dressing conditions on the grinding response variables. However, the choice of the dressing conditions is often made, based on the experience of the qualified staff or using data from reference books. The optimal dressing parameters, which are only valid for the particular methods and dressing and grinding conditions, are also used. The paper presents a methodology for optimization of the dressing parameters in cylindrical grinding. The generalized utility function has been chosen as an optimization parameter. It is a complex indicator determining the economic, dynamic and manufacturing characteristics of the grinding process. The developed methodology is implemented for the dressing of aluminium oxide grinding wheels by using experimental diamond roller dressers with different grit sizes made of medium- and high-strength synthetic diamonds type ??32 and ??80. To solve the optimization problem, a model of the generalized utility function is created which reflects the complex impact of dressing parameters. The model is built based on the results from the conducted complex study and modeling of the grinding wheel lifetime, cutting ability, production rate and cutting forces during grinding. They are closely related to the dressing conditions (dressing speed ratio, radial in-feed of the diamond roller dresser and dress-out time), the diamond roller dresser grit size/grinding wheel grit size ratio, the type of synthetic diamonds and the direction of dressing. Some dressing parameters are determined for which the generalized utility function has a maximum and which guarantee an optimum combination of the following: the lifetime and cutting ability of the abrasive wheels, the tangential cutting force magnitude and the production rate of the grinding process. The results obtained prove the possibility of control and optimization of grinding by selecting particular dressing

  4. Innovative grinding wheel design for cost-effective machining of advanced ceramics. Phase I, final report

    Energy Technology Data Exchange (ETDEWEB)

    Licht, R.H.; Ramanath, S.; Simpson, M.; Lilley, E.

    1996-02-01

    Norton Company successfully completed the 16-month Phase I technical effort to define requirements, design, develop, and evaluate a next-generation grinding wheel for cost-effective cylindrical grinding of advanced ceramics. This program was a cooperative effort involving three Norton groups representing a superabrasive grinding wheel manufacturer, a diamond film manufacturing division and a ceramic research center. The program was divided into two technical tasks, Task 1, Analysis of Required Grinding Wheel Characteristics, and Task 2, Design and Prototype Development. In Task 1 we performed a parallel path approach with Superabrasive metal-bond development and the higher technical risk, CVD diamond wheel development. For the Superabrasive approach, Task 1 included bond wear and strength tests to engineer bond-wear characteristics. This task culminated in a small-wheel screening test plunge grinding sialon disks. In Task 2, an improved Superabrasive metal-bond specification for low-cost machining of ceramics in external cylindrical grinding mode was identified. The experimental wheel successfully ground three types of advanced ceramics without the need for wheel dressing. The spindle power consumed by this wheel during test grinding of NC-520 sialon is as much as to 30% lower compared to a standard resin bonded wheel with 100 diamond concentration. The wheel wear with this improved metal bond was an order of magnitude lower than the resin-bonded wheel, which would significantly reduce ceramic grinding costs through fewer wheel changes for retruing and replacements. Evaluation of ceramic specimens from both Tasks 1 and 2 tests for all three ceramic materials did not show evidence of unusual grinding damage. The novel CVD-diamond-wheel approach was incorporated in this program as part of Task 1. The important factors affecting the grinding performance of diamond wheels made by CVD coating preforms were determined.

  5. A study of energy-size relationship and wear rate in a lab-scale high pressure grinding rolls unit

    Science.gov (United States)

    Rashidi Dashtbayaz, Samira

    This study is focused on two independent topics of energy-size relationship and wear-rate measurements on a lab-scale high pressure grinding rolls (HPGR). The first part of this study has been aimed to investigate the influence of the operating parameters and the feed characteristics on the particle-bed breakage using four different ore samples in a 200 mm x 100 mm lab-scale HPGR. Additionally, multistage grinding, scale-up from a lab-scale HPGR, and prediction of the particle size distributions have been studied in detail. The results obtained from energy-size relationship studies help with better understanding of the factors contributing to more energy-efficient grinding. It will be shown that the energy efficiency of the two configurations of locked-cycle and open multipass is completely dependent on the ore properties. A test procedure to produce the scale-up data is presented. The comparison of the scale-up factors between the data obtained on the University of Utah lab-scale HPGR and the industrial machine at the Newmont Boddington plant confirmed the applicability of lab-scale machines for trade-off studies. The population balance model for the simulation of product size distributions has shown to work well with the breakage function estimated through tests performed on the HPGR at high rotational speed. Selection function has been estimated by back calculation of population balance model with the help of the experimental data. This is considered to be a major step towards advancing current research on the simulation of particle size distribution by using the HPGR machine for determining the breakage function. Developing a technique/setup to measure the wear rate of the HPGR rolls' surface is the objective of the second topic of this dissertation. A mockup was initially designed to assess the application of the linear displacement sensors for measuring the rolls' weight loss. Upon the analysis of that technique and considering the corresponding sources of

  6. The effect of wheel eccentricity and run-out on grinding forces, waviness, wheel wear and chatter

    OpenAIRE

    O'DONNELL, GARRET; MURPHY, STUART

    2011-01-01

    PUBLISHED The effect of grinding-wheel eccentricity on grinding forces, wheel wear and final waviness height was studied. Eccentricity was evident in force oscillations and acceleration and audio measurements. A model was developed to predict final scallop-profile shape from grinding parameters and eccentricity. Recommendations are given on detecting eccentricity and determining when eccentricity is tolerable.

  7. Comparison of tungsten carbide and stainless steel ball bearings for grinding single maize kernels in a reciprocating grinder

    Science.gov (United States)

    Reciprocating grinders can grind single maize kernels by shaking the kernel in a vial with a ball bearing. This process results in a grind quality that is not satisfactory for many experiments. Tungesten carbide ball bearings are nearly twice as dense as steel, so we compared their grinding performa...

  8. Pyrolysis of a waste from the grinding of scrap tyres.

    Science.gov (United States)

    Fernández, A M; Barriocanal, C; Alvarez, R

    2012-02-15

    The fibres that are used to reinforce tyres can be recovered as a waste in the process of grinding of scrap tyres. In this paper beneficiation through pyrolysis is studied since the fibres are made up of polymers with a small amount of rubber because the latter is difficult to separate. The experiments were performed at three temperatures (400, 550 and 900°C) in a horizontal oven. The three products - gas, oil and char - obtained from the pyrolysis were investigated. The composition of the gas was analyzed by means of gas chromatography. The oil was studied by gas chromatography and infrared spectroscopy. The char porous structure was determined by N(2) adsorption. In addition, the topography of the chars was studied by means of scanning electron microscopy (SEM). The products resulting from the pyrolysis of the fibres were compared with those obtained from scrap rubber. Copyright © 2011 Elsevier B.V. All rights reserved.

  9. Intra-pulp temperature increase of equine cheek teeth during treatment with motorized grinding systems: influence of grinding head position and rotational speed.

    Science.gov (United States)

    Haeussler, Silvia; Luepke, Matthias; Seifert, Hermann; Staszyk, Carsten

    2014-02-21

    In equine practice, teeth corrections by means of motorized grinding systems are standard procedure. The heat resulting from that treatment may cause irreparable damage to the dental pulp. It has been shown that a 5.5°C temperature rise may cause severe destruction in pulp cells. Hence, the capability to continuously form secondary dentine is lost, and may lead, due to equine-typical occlusal tooth abrasion, to an opening of the pulp cavity.To obtain reliable data on the intra-pulp increase in temperature during corrective treatments, equine cheek teeth (CT) were modified in a way (occlusal surface smoothed, apical parts detached, pulp horns standardized) that had been qualified in own former published studies. All parameters influencing the grinding process were standardized (force applied, initial temperatures, dimensions of pulp horns, positioning of grinding disk, rotational speed). During grinding experiments, imitating real dental treatments, the time span for an intra-pulp temperature increase of 5.5°C was determined. The minimum time recorded for an intra-pulp temperature increase of 5.5°C was 38 s in mandibular CT (buccal grinding, 12,000 rpm) and 70 s in maxillary CT (flat occlusal grinding, 12,000 rpm). The data obtained showed that doubling the rotational speed of the disk results in halving the time span after which the critical intra-pulp temperature increase in maxillary CT is reached. For mandibular CT, the time span even drops by two thirds. The use of standardized hypsodont CT enabled comparative studies of intra-pulp heating during the grinding of occlusal tooth surfaces using different tools and techniques. The anatomical structure of the natural vital hypsodont tooth must be kept in mind, so that the findings of this study do not create a deceptive sense of security with regard to the time-dependent heating of the native pulp.

  10. Analysis of grinding of superalloys and ceramics for off-line process optimization

    Science.gov (United States)

    Sathyanarayanan, G.

    The present study has compared the performances of resinoid, vitrified, and electroplated CBN wheels in creep feed grinding of M42 and D2 tool steels. Responses such as a specific energy, normal and tangential forces, and surface roughness were used as measures of performance. It was found that creep feed grinding with resinoid, vitrified, and electroplated CBN wheels has its own advantages, but no single wheel could provide good finish, lower specific energy, and high material removal rates simultaneously. To optimize the CBN grinding with different bonded wheels, a Multiple Criteria Decision Making (MCDM) methodology was used. Creep feed grinding of superalloys, Ti-6Al-4V and Inconel 718, has been modeled by utilizing neural networks to optimize the grinding process. A parallel effort was directed at creep feed grinding of alumina ceramics with diamond wheels to investigate the influence of process variables on responses based on experimental results and statistical analysis. The conflicting influence of variables was observed. This led to the formulation of ceramic grinding process as a multi-objective nonlinear mixed integer problem.

  11. Effect of ceramic thickness, grinding, and aging on the mechanical behavior of a polycrystalline zirconia

    Directory of Open Access Journals (Sweden)

    Rodrigo Diniz PRADO

    2017-11-01

    Full Text Available Abstract Monolithic restorations of Y-TZP have been recommended as a restorative alternative on prosthetic dentistry as it allows a substantial reduction of ceramic thickness, which means a greater preservation of tooth structure. However, the influence of grinding and aging when using a thinner layer of the material is unclear. This investigation aimed to evaluate and compare the effects of ceramic thickness (0.5 mm and 1.0 mm, grinding and aging (low-temperature degradation on the mechanical behavior and surface characteristics of a full-contour Y-TZP ceramic. Y-TZP disc-shaped specimens (15 mm diameter were manufactured with both thicknesses and randomly assigned into 4 groups considering the factors ‘grinding with diamond bur’ and ‘aging in autoclave’. Surface topography (roughness, 3D profilometry and SEM, phase transformation, flexural strength and structural reliability (Weibull analyses were executed. Grinding affected the surface topography, while aging did not promote any effect. An increase in m-phase content was observed after grinding and aging, although different susceptibilities were observed. Regardless of zirconia’s thickness, no deleterious effect of grinding or aging on the mechanical properties was observed. Thus, in our testing assembly, reducing the thickness of the Y-TZP ceramic did not alter its response to grinding and low temperature degradation and did not impair its mechanical performance.

  12. Effect of ceramic thickness, grinding, and aging on the mechanical behavior of a polycrystalline zirconia.

    Science.gov (United States)

    Prado, Rodrigo Diniz; Pereira, Gabriel Kalil Rocha; Bottino, Marco Antonio; Melo, Renata Marques de; Valandro, Luiz Felipe

    2017-11-06

    Monolithic restorations of Y-TZP have been recommended as a restorative alternative on prosthetic dentistry as it allows a substantial reduction of ceramic thickness, which means a greater preservation of tooth structure. However, the influence of grinding and aging when using a thinner layer of the material is unclear. This investigation aimed to evaluate and compare the effects of ceramic thickness (0.5 mm and 1.0 mm), grinding and aging (low-temperature degradation) on the mechanical behavior and surface characteristics of a full-contour Y-TZP ceramic. Y-TZP disc-shaped specimens (15 mm diameter) were manufactured with both thicknesses and randomly assigned into 4 groups considering the factors 'grinding with diamond bur' and 'aging in autoclave'. Surface topography (roughness, 3D profilometry and SEM), phase transformation, flexural strength and structural reliability (Weibull) analyses were executed. Grinding affected the surface topography, while aging did not promote any effect. An increase in m-phase content was observed after grinding and aging, although different susceptibilities were observed. Regardless of zirconia's thickness, no deleterious effect of grinding or aging on the mechanical properties was observed. Thus, in our testing assembly, reducing the thickness of the Y-TZP ceramic did not alter its response to grinding and low temperature degradation and did not impair its mechanical performance.

  13. Effects of metal surface grinding at the porcelain try-in stage of fixed dental prostheses.

    Science.gov (United States)

    Kılınç, Halil İbrahim; Kesim, Bülent; Gümüş, Hasan Önder; Dinçel, Mehmet; Erkaya, Selçuk

    2014-08-01

    This study was to evaluate the effect of grinding of the inner metal surface during the porcelain try-in stage on metal-porcelain bonding considering the maximum temperature and the vibration of samples. Ninety-one square prism-shaped (1 × 1 × 1.5 mm) nickel-chrome cast frameworks 0.3 mm thick were prepared. Porcelain was applied on two opposite outer axial surfaces of the frameworks. The grinding was performed from the opposite axial sides of the inner metal surfaces with a low-speed handpiece with two types of burs (diamond, tungsten-carbide) under three grinding forces (3.5 N, 7 N, 14 N) and at two durations (5 seconds, 10 seconds). The shear bond strength (SBS) test was performed with universal testing machine. Statistical analyzes were performed at 5% significance level. The samples subjected to grinding under 3.5 N showed higher SBS values than those exposed to grinding under 7 N and 14 N (P.05). The types of bur (P=.965) and the duration (P=.679) did not affect the SBS values. On the other hand, type of bur, force applied, and duration of the grinding affected the maximum temperatures of the samples, whereas the maximum vibration was affected only by the type of bur (PGrinding the inner metal surface did not affect the metal-porcelain bond strength. Although the grinding affected the maximum temperature and the vibration values of the samples, these did not influence the bonding strength.

  14. The effect of seed moisture and temperature on grinding characteristics of quinoa (Chenopodium quinoa Willd.

    Directory of Open Access Journals (Sweden)

    Hassoon Waleed Hameed

    2018-01-01

    Full Text Available Quinoa (Chenopodium quinoa Willd is a native food plant of the Andean region of South America. Quinoa seeds have remarkable nutritional properties, not only from its high protein content, but also from its good amino acid balance. The aim of the study was evaluate the influence of quinoa seed moisture content (10, 12, 14, 16 and 18% and temperature (-20, 3, 20 and 40°C, with the initial grain moisture content of 10.5% on grinding process. Especially the particle size distributions and grinding energy indices were determined. The results showed that the increase of seed moisture content from 10 to 16% caused an increase the specific grinding energy from 6.9 to 8.3 kJ·kg-1, beside of this as the moisture increased the average particle also increased. The highest changes were observed in the fraction of coarse particles (above 1.0 mm. Interestingly, the mass fraction of fine particles (below 0.2 mm also increased. Other grinding indices also confirmed an increase the grinding energy requirements with the increase seed moisture content. The temperature of seed has little influence on quinoa grinding process. The highest grinding energy requirements were observed when the frozen seeds were ground.

  15. Determination of the boundary conditions of the grinding load in ball mills

    Science.gov (United States)

    Sharapov, Rashid R.

    2018-02-01

    The prospects of application in ball mills for grinding cement clinker with inclined partitions are shown. It is noted that ball mills with inclined partitions are more effective. An algorithm is proposed for calculating the power consumed by a ball mill with inclined inter-chamber partitions in which an axial movement of the ball load takes place. The boundary conditions in which the ball load is located are determined. The equations of bounding the grinding load are determined. The behavior of a grinding load is considered in view of the characteristic cross sections. The coordinates of the centers of gravity of the grinding load with a definite step and the shape of the cross sections are determined. It is theoretically shown that grinding load in some parts of the ball mill not only consumes, but also helps to rotate the ball mill. Methods for calculating complex analytical expressions for determining the coordinates of the centers of gravity of the grinding load under the conditions of its longitudinal motion have developed. The carried out researches allow to approach from the general positions to research of behavior of a grinding load in the ball mills equipped with various in-mill devices.

  16. Optimum condition determination of Rirang uranium ores grinding using ball mill

    International Nuclear Information System (INIS)

    Affandi, Kosim; Waluyo, Sugeng; Sarono, Budi; Sujono; Muhammad

    2002-01-01

    The grinding experiment on Rirang Uranium ore has been carried out with the aim is to find out the optimum condition of wet grinding using ball mill to produce particle size -325, -200 and -100 mesh. This will be used for decomposition feed the test was done by examine the parameters comparison of ore's weight against ball's weight and time of grinding. The test shown that the product of particle size -325 meshes was achieved optimum condition at the comparison ore's weight: ball = 1:3, grinding time 150 minutes, % solid 60, speed rotation of ball mill 60 rpm and recovery of grinding was 93.51 % of -325 mesh. The product of particle size -200 mesh was achieved optimum condition at comparison ore's weight: ball = 1:2, time of grinding 60 minutes, the fraction of + 200 mesh was regrind, the recovery of grinding 6.82% at particle size of (-200 + 250) mesh, 5.75 % at (-250 + 325)m mesh and, 47.93 % -325 mesh. The product of particle size -100 mesh was achieved the optimum condition at comparison ore's weight: ball = 1:2, time of grinding at 30 minutes particle size +100 mesh regrinding using mortar grinder, recovery of grinding 30.10% at particle size (-100 + 150) m, 12.28 % at (-150 + 200) mesh, 15.92 % at (-200 + 250) mesh, 12.44 % at (-250 + 325) mesh and 29.26 % -325 mesh. The determination of specific gravity of Rirang uranium ore was between 4.15 - 4.55 g/cm 3

  17. Neuromorphic Deep Learning Machines

    OpenAIRE

    Neftci, E; Augustine, C; Paul, S; Detorakis, G

    2017-01-01

    An ongoing challenge in neuromorphic computing is to devise general and computationally efficient models of inference and learning which are compatible with the spatial and temporal constraints of the brain. One increasingly popular and successful approach is to take inspiration from inference and learning algorithms used in deep neural networks. However, the workhorse of deep learning, the gradient descent Back Propagation (BP) rule, often relies on the immediate availability of network-wide...

  18. Modelling transfer of Salmonella Typhimurium DT104 during simulation of grinding of pork

    DEFF Research Database (Denmark)

    Møller, Cleide; Nauta, Maarten; Christensen, B. B.

    2012-01-01

    Aims: The aim of this study was to develop a model to predict cross‐contamination of Salmonella during grinding of pork. Methods and Results: Transfer rates of Salmonella were measured in three experiments, where between 10 and 20 kg meat was ground into 200‐g portions. In each experiment, five...... during a small‐scale grinding process. It was, therefore, hypothesized that transfer occurred from two environmental matrices inside the grinder and a model was developed. The developed model satisfactorily predicted the observed concentrations of Salmonella during its cross‐contamination in the grinding...

  19. The effect of structurally related impurities on crystallinity reduction of sulfamethazine by grinding.

    Science.gov (United States)

    Hamada, Yoshito; Ono, Makoto; Ohara, Motomu; Yonemochi, Etsuo

    2016-12-30

    In this study, the effect of structurally related impurities on crystallinity reduction of sulfamethazine by grinding was evaluated. The crystallinity of sulfamethazine was not decreased when it was ground alone. However, when structurally related impurities with sulfonamide derivatives were blended, the crystallinity of sulfamethazine was decreased by grinding. Other materials without a sulfonamide moiety showed no such effect. The Raman spectra of sulfamethazine demonstrated that there was a difference between its crystalline and amorphous states within its sulfonamide structure. It was suggested that the sulfonamide structure of the impurities was important in causing the inhibition of recrystallization of sulfamethazine during grinding. Copyright © 2016 Elsevier B.V. All rights reserved.

  20. Effect of liquid active media on grinding and scratching of solids

    International Nuclear Information System (INIS)

    Pertsov, N.V.; Danilova, F.B.; Babat, I.G.

    1975-01-01

    In the present paper the influence of various liquid active media on grinding of tungsten carbide, hard alloy T 15 K 6, oxide of aluminium A995 and other materials with diamond grinding wheels is investigated. A grinding device is described. The results of the investigations show that materials with metallic type of bonds are most effectively treated in the medium of liquid metals; for material with an ionic structure the active media are water and aqueous solutions of electrolytes. It is pointed out that liquid active media will diminish the specific work of dispergation by as much as one order of magnitude

  1. STUDY OF GRINDING PROCESS OF TITANIUM CARBIDE PRODUCED WITH SELF-PROPAGATING HIGH TEMPERATURE SYNTHESIS (SPHTS)

    International Nuclear Information System (INIS)

    Kovziridze, Z.; Tabatadze, G.; Donadze, G.; Lezhava, A.; Gventsadze, D.

    2006-01-01

    It is stated that the specific character of SPHTS-preparations of TiC_x consists in crystal lattice strength reflecting the condition of synthesis in ''burning wave''. The use of roentgenographic and other methods of analysis allows to estimate the effect of the conditions of synthesis, causing carbon sublattice defect on grinding intensity of TiC_x phases. Study of the kinetics of vibro-grinding of TiC_x-phases in ethanol and benzene medium allows to establish high grinding intensity of the phases close to stoichiometry and the possibility of high depresion powderds (S_s_p H'' 4.5-6 m"2/g). (author)

  2. Synthesis and characterization of grinding aid fly ash blended mortar effect on bond strength of masonry prisms

    Science.gov (United States)

    Krishnaraj, L.; Ravichandran, P. T.; Sagadevan, Suresh

    2018-04-01

    The aim of the present work is to study the effect of particle size reduction by applying top-down nanotechnology such as ball mill grinding process with the addition of amine-based grinding aids. The particle size reduction in synthesis process and its characterization were investigated for fly ash particles. The Rosin-Rammler-Bennet (RRB) distribution model using mathematical formulations were studied for fly ash ground particles. The hardened properties of grinding aid fly ash composite mortar were studied using compressive strength test. The optimum grinding time was 120 min identified through the particle size distribution analysis. The mean particle size decreased from 92.09 μm to 10.5 μm in which there is 89% reduction in particle size due to the grinding of fly ash particle with grinding aids. The compressive strength results show that substitutions of Ordinary Portland Cement (OPC) mortar by Amine-based Grinding aid Fly Ash (AGFA) 15% gives 12, 23% and at 30% gives 6, 8% of higher strength compare to the substitutions of raw fly ash. The addition of grinding aids in grinding process gives more advantages to reduce the particle size without changing chemical composition. The AGFA sample shows better performance in compressive strength and bond strength behavior of masonry prism. It may suggest that amine based grinding aids play a vital role and feasible to use in fly ash grinding process.

  3. The grinding behavior of ground copper powder for Cu/CNT nanocomposite fabrication by using the dry grinding process with a high-speed planetary ball mill

    Science.gov (United States)

    Choi, Heekyu; Bor, Amgalan; Sakuragi, Shiori; Lee, Jehyun; Lim, Hyung-Tae

    2016-01-01

    The behavior of ground copper powder for copper-carbon nanotube (copper-CNT) nanocomposite fabrication during high-speed planetary ball milling was investigated because the study of the behavior characteristics of copper powder has recently gained scientific interest. Also, studies of Cu/CNT composites have widely been done due to their useful applications to enhanced, advanced nano materials and components, which would significantly improve the properties of new mechatronics-integrated materials and components. This study varied experimental conditions such as the rotation speed and the grinding time with and without CNTs, and the particle size distribution, median diameter, crystal structure and size, and particle morphology were monitored for a given grinding time. We observed that pure copper powders agglomerated and that the morphology changed with changing rotation speed. The particle agglomerations were observed with maximum experiment conditions (700 rpm, 60 min) in this study of the grinding process for mechanical alloys in the case of pure copper powders because the grinding behavior of Cu/CNT agglomerations was affected by the addition of CNTs. Indeed, the powder morphology and the crystal size of the composite powder could be changed by increasing the grinding time and the rotation speed.

  4. A Wide Band Gap Polymer with a Deep Highest Occupied Molecular Orbital Level Enables 14.2% Efficiency in Polymer Solar Cells.

    Science.gov (United States)

    Li, Sunsun; Ye, Long; Zhao, Wenchao; Yan, Hongping; Yang, Bei; Liu, Delong; Li, Wanning; Ade, Harald; Hou, Jianhui

    2018-05-21

    To simultaneously achieve low photon energy loss ( E loss ) and broad spectral response, the molecular design of the wide band gap (WBG) donor polymer with a deep HOMO level is of critical importance in fullerene-free polymer solar cells (PSCs). Herein, we developed a new benzodithiophene unit, i.e., DTBDT-EF, and conducted systematic investigations on a WBG DTBDT-EF-based donor polymer, namely, PDTB-EF-T. Due to the synergistic electron-withdrawing effect of the fluorine atom and ester group, PDTB-EF-T exhibits a higher oxidation potential, i.e., a deeper HOMO level (ca. -5.5 eV) than most well-known donor polymers. Hence, a high open-circuit voltage of 0.90 V was obtained when paired with a fluorinated small molecule acceptor (IT-4F), corresponding to a low E loss of 0.62 eV. Furthermore, side-chain engineering demonstrated that subtle side-chain modulation of the ester greatly influences the aggregation effects and molecular packing of polymer PDTB-EF-T. With the benefits of the stronger interchain π-π interaction, the improved ordering structure, and thus the highest hole mobility, the most symmetric charge transport and reduced recombination are achieved for the linear decyl-substituted PDTB-EF-T (P2)-based PSCs, leading to the highest short-circuit current density and fill factor (FF). Due to the high Flory-Huggins interaction parameter (χ), surface-directed phase separation occurs in the P2:IT-4F blend, which is supported by X-ray photoemission spectroscopy results and cross-sectional transmission electron microscope images. By taking advantage of the vertical phase distribution of the P2:IT-4F blend, a high power conversion efficiency (PCE) of 14.2% with an outstanding FF of 0.76 was recorded for inverted devices. These results demonstrate the great potential of the DTBDT-EF unit for future organic photovoltaic applications.

  5. Fabrication of blue luminescent MoS{sub 2} quantum dots by wet grinding assisted co-solvent sonication

    Energy Technology Data Exchange (ETDEWEB)

    Ali, Junaid; Siddiqui, Ghayas Uddin [Department of Mechatronics Engineering, Jeju National University, Jeju (Korea, Republic of); Choi, Kyung Hyun, E-mail: amm@jejunu.ac.kr [Department of Mechatronics Engineering, Jeju National University, Jeju (Korea, Republic of); Jang, Yunseok [Department of Printed Electronics, Korea Institute of Machinery & Materials, Daejeon, Republic of Korea (Korea, Republic of); Lee, Kangtaek [Department of Chemical and Biomolecular Engineering, Yonsei University (Korea, Republic of)

    2016-01-15

    Molybdenum disulfide (MoS{sub 2}) belongs to transition-metal dichalcogenides (TMDs) family and has vital position among 2D materials. Here, an efficient strategy for the synthesis of zero-dimensional MoS{sub 2} quantum dots (QDs) has been represented. This strategy consists of wet grinding of pristine MoS{sub 2} in N-methyl-2-pyrrolidone (NMP) followed by sonication in NMP and 1,2-dichlorobenzene (o-DCB). The efficacy of this approach to synthesize MoS{sub 2} QDs has been reported by analyzing the as synthesized MoS{sub 2} QDs by different characterization techniques such as high resolution transmission electron microscopy, energy dispersive x-ray spectroscopy, Raman spectroscopy, photoluminescence spectroscopy, Fourier transform infrared spectroscopy and UV–vis spectroscopy. The concentration (yield) of as synthesized MoS{sub 2} QDs was found to be 7 mg mL{sup −1}. Most of the MoS{sub 2} QDs were measured around 2–5 nm in size. The as synthesized MoS{sub 2} QDs showed distinct blue luminescence upon UV excitation. - Highlights: • Synthesis of MoS{sub 2} quantum dots. • Wet grinding of MoS{sub 2} flakes for 6 h in NMP. • Ultrasonication of MoS{sub 2} in NMP and DCB. • Particle size 2–5 nm and concentration 7 mg/ml. • MoS{sub 2} QDs showed blue luminescence.

  6. A method of detection to the grinding wheel layer thickness based on computer vision

    Science.gov (United States)

    Ji, Yuchen; Fu, Luhua; Yang, Dujuan; Wang, Lei; Liu, Changjie; Wang, Zhong

    2018-01-01

    This paper proposed a method of detection to the grinding wheel layer thickness based on computer vision. A camera is used to capture images of grinding wheel layer on the whole circle. Forward lighting and back lighting are used to enables a clear image to be acquired. Image processing is then executed on the images captured, which consists of image preprocessing, binarization and subpixel subdivision. The aim of binarization is to help the location of a chord and the corresponding ring width. After subpixel subdivision, the thickness of the grinding layer can be calculated finally. Compared with methods usually used to detect grinding wheel wear, method in this paper can directly and quickly get the information of thickness. Also, the eccentric error and the error of pixel equivalent are discussed in this paper.

  7. Effect of electroerosion grinding parameters on surface quality of cylindrical pieces out of tungsten monocrystals

    International Nuclear Information System (INIS)

    Zolotykh, B.N.; Marchuk, A.I.; Nikiforov, S.V.; Serdobov, B.F.; Yakunkin, M.M.

    1978-01-01

    Experimental data are presented on the examination of the electroerosion grinding of cylindrical parts made up of tungsten single crystals. Special attention has been paid to a comparative analysis of the influence of the electroerosion cutting out and grinding on the quality characteristics of a surface. The surface quality was assessed according to a widening of the X-ray emission line (110) by means of round diffraction patterns and by the metallographic method. It is shown that the microdistortions after the electroerosion grinding are considerably greater than those resulting from the electroerosion cutting out; however, after the electroerosion grinding the number of microcracks is considerably smaller. The experimental results obtained underwent a theoretical analysis within the framework of the Mitchell-Rockswell-Hirsch dislocation theory of failure of space-centered single crystals

  8. New Integrals Arising in the Samara-Valencia Heat Transfer Model in Grinding

    Directory of Open Access Journals (Sweden)

    J. L. González-Santander

    2017-01-01

    Full Text Available The Samara-Valencia model for heat transfer in grinding has been recently used for calculating nontabulated integrals. Based on these results, new infinite integrals can be calculated, involving the Macdonald function and the modified Struve function.

  9. TECHNICAL NOTE: High-speed grinding using thin abrasive disks for microcomponents

    Science.gov (United States)

    Yeo, S. H.; Balon, S. A. P.

    2002-01-01

    This paper introduces the development of a high-speed grinding device for cylindrical grinding of microcomponents made of hard and brittle materials. The study made use of an ultraprecision diamond turning machine tool as a basic platform. The novelty of the device is based on the high-speed air bearing spindle with a thin grinding wheel, similar to the dicing technology for silicon wafer fabrication. The spindle attachment is inclined at an angle to the main spindle which holds the precision fixture mechanism via the vacuum chuck. Experiments have been conducted to verify the design and implementation of the grinding methodology. A feature size as small as 31 μm in diameter and average surface roughness of 98 nm were obtained in the experimental work. It is found that the work done is capable of manufacturing miniature components, such as microcylindrical stepped shafts.

  10. Precision grinding of microarray lens molding die with 4-axes controlled microwheel

    Directory of Open Access Journals (Sweden)

    Yuji Yamamoto, Hirofumi Suzuki, Takashi Onishi1, Tadashi Okino and Toshimichi Moriwaki

    2007-01-01

    Full Text Available This paper deals with precision grinding of microarray lens (fly eye molding die by using a resinoid bonded diamond wheel. An ultra-precision grinding system of microarray lens molding die and new truing method of resinoid bonded diamond wheel were developed. In this system, a grinding wheel was four-dimensionally controlled with 1 nm resolution by linear scale feedback system and scanned on the workpiece surface. New truing method by using a vanadium alloy tool was developed and its performance was obtained with high preciseness and low wheel wear. Finally, the microarray lens molding dies of fine grain tungsten carbide (WC was tested with the resinoid bonded diamond wheel to evaluate grinding performance.

  11. DETERMINATION AND OPTIMIZATION OF CYLINDRICAL GRINDING PROCESS PARAMETERS USING TAGUCHI METHOD AND REGRESSION ANALYSIS

    OpenAIRE

    M.Janardhan; Dr.A.Gopala Krishna

    2011-01-01

    Cylindrical grinding is one of the important metal cutting processes used extensively in the finishing operations. Metal removal rate and surface finish are the important out put responses in the production with respect to quantity and quality respectively. The Experiments are conducted on CNC cylindrical grinding machine with L9 Orthogonal array with input machining variables as work speed, feed rate and depth of cut. Empirical models are developed using design of experiments and response su...

  12. Surface roughness of zirconia for full-contour crowns after clinically simulated grinding and polishing.

    Science.gov (United States)

    Hmaidouch, Rim; Müller, Wolf-Dieter; Lauer, Hans-Christoph; Weigl, Paul

    2014-12-01

    The aim of this study was to evaluate the effect of controlled intraoral grinding and polishing on the roughness of full-contour zirconia compared to classical veneered zirconia. Thirty bar-shaped zirconia specimens were fabricated and divided into two groups (n=15). Fifteen specimens (group 1) were glazed and 15 specimens (group 2) were veneered with feldspathic ceramic and then glazed. Prior to grinding, maximum roughness depth (Rmax) values were measured using a profilometer, 5 times per specimen. Simulated clinical grinding and polishing were performed on the specimens under water coolant for 15 s and 2 N pressure. For grinding, NTI diamonds burs with grain sizes of 20 µm, 10 µm, and 7.5 µm were used sequentially. The ground surfaces were polished using NTI kits with coarse, medium and fine polishers. After each step, Rmax values were determined. Differences between groups were examined using one-way analysis of variance (ANOVA). The roughness of group 1 was significantly lower than that of group 2. The roughness increased significantly after coarse grinding in both groups. The results after glazing were similar to those obtained after fine grinding for non-veneered zirconia. However, fine-ground veneered zirconia had significantly higher roughness than venerred, glazed zirconia. No significant difference was found between fine-polished and glazed zirconia, but after the fine polishing of veneered zirconia, the roughness was significantly higher than after glazing. It can be concluded that for full-contour zirconia, fewer defects and lower roughness values resulted after grinding and polishing compared to veneered zirconia. After polishing zirconia, lower roughness values were achieved compared to glazing; more interesting was that the grinding of glazed zirconia using the NTI three-step system could deliver smooth surfaces comparable to untreated glazed zirconia surfaces.

  13. Temperature measurement of flat glass edge during grinding and effect of wheel and workpiece speeds

    International Nuclear Information System (INIS)

    Moussa, Tala; Garnier, Bertrand; Peerhossaini, Hassan

    2017-01-01

    Flat glass temperature at the vicinity of the grinding wheel during grinding can become very high and reach that of the glass transition (typically around 550–600 °C). In such cases, the mechanical strength of glass is greatly affected and the grinding process cannot be carried out properly. Hence, thermal phenomena must be managed by adjusting the machining parameters to avoid overheating. For this purpose, it is very important to be able to measure the glass temperature, especially at the grinding interface. However, measuring the interfacial glass temperature is difficult and none of the existing methods for metal grinding is adequate for glass grinding. This work shows a novel temperature method that uses constantan and copper strips on both sides of the glass plates; thermoelectric contact being provided by the metallic binder of diamond particles in the grinding wheel. This new technique allows the measurement of the glass edge temperature during the wheel displacement around the glass plate. The experimental results show an average glass edge temperature between 300 and 600 °C depending on the value of the machining parameters such as work speed, wheel speed, depth of cut and water coolant flow rate. As this new thermal instrumentation is rather intrusive, glass temperature biases were analysed using a 3D heat transfer model with a moving source. Model computations performed using finite elements show that the temperature biases are less than 70 °C, which is smaller than the standard deviation of the glass edge temperatures measured during grinding. (paper)

  14. Effect of ultrasound on dynamics characteristic of the cavitation bubble in grinding fluids during honing process.

    Science.gov (United States)

    Guo, Ce; Zhu, Xijing

    2018-03-01

    The effect of ultrasound on generating and controlling the cavitation bubble of the grinding fluid during ultrasonic vibration honing was investigated. The grinding fluid on the surface of the honing stone was measured by utilizing the digital microscope VHX-600ESO. Based on analyzing the cavitation mechanism of the grinding fluid, the bubble dynamics model under conventional honing (CH) and ultrasonic vibration honing (UVH) was established respectively. Difference of dynamic behaviors of the bubble between the cases in UVH and CH was compared respectively, and the effects of acoustic amplitude and ultrasonic frequency on the bubble dynamics were simulated numerically using the Runge-Kutta fourth order method with variable step size adaptive control. Finally, the cavitation intensity of grinding fluids under ultrasound was measured quantitatively using acoustimeter. The results showed that the grinding fluid subjected to ultrasound can generate many bubbles and further forms numerous groups of araneose cavitation bubbles on the surface of the honing stone. The oscillation of the bubble under UVH is more intense than the case under CH, and the maximum velocity of the bubble wall under UVH is higher two magnitudes than the case under CH. For lower acoustic amplitude, the dynamic behaviors of the bubble under UVH are similar to that case under CH. As increasing acoustic amplitude, the cavitation intensity of the bubble is growing increased. Honing pressure has an inhabitation effect on cavitation effect of the grinding fluid. The perfect performance of cavitation of the grinding fluid can be obtained when the device of UVH is in the resonance. However, the cavitation intensity of the grinding fluid can be growing weakened with increasing ultrasonic frequency, when the device of UVH is in the off-resonance. The experimental results agree with the theoretical and numerical analysis, which provides a method for exploring applications of the cavitation effect in

  15. Effect of different grinding burs on the physical properties of zirconia.

    Science.gov (United States)

    Lee, Kyung-Rok; Choe, Han-Cheol; Heo, Yu-Ri; Lee, Jang-Jae; Son, Mee-Kyoung

    2016-04-01

    Grinding with less stress on 3Y-TZP through proper selection of methods and instruments can lead to a long-term success of prosthesis. The purpose of this study was to compare the phase transformation and physical properties after zirconia surface grinding with 3 different grinding burs. Forty disc-shaped zirconia specimens were fabricated. Each Ten specimens were ground with AllCeramic SuperMax (NTI, Kahla, Germany), Dura-Green DIA (Shofu Inc., Kyoto, Japan), and Dura-Green (Shofu Inc., Kyoto, Japan). Ten specimens were not ground and used as a control group. After the specimen grinding, XRD analysis, surface roughness test, FE-SEM imaging, and biaxial flexural strength test were performed. After surface grinding, small amount of monoclinic phase in all experimental groups was observed. The phase change was higher in specimens, which were ground with Dura-Green DIA and AllCeramic SuperMax burs. The roughness of surfaces increased in specimens, which were ground with Dura-Green DIA and AllCeramic SuperMax burs than control groups and ground with Dura-Green. All experimental groups showed lower flexural strength than control group, but there was no statistically significant difference between control group and ground with Dura-Green DIA and AllCeramic SuperMax burs. The specimens, which were ground with Dura- Green showed the lowest strength. The use of dedicated zirconia-specific grinding burs such as Dura-Green DIA and AllCeramic SuperMax burs decreases the grinding time and did not significantly affect the flexural strength of zirconia, and therefore, they may be recommended. However, a fine polishing process should be accompanied to reduce the surface roughness after grinding.

  16. Effect of cryogenic grinding on volatile and fatty oil constituents of cumin (Cuminum cyminum L.) genotypes.

    Science.gov (United States)

    Sharma, L K; Agarwal, D; Rathore, S S; Malhotra, S K; Saxena, S N

    2016-06-01

    Effect of cryogenic grinding on recovery of volatile oil, fatty oil percentage and their constituents in two cumin (Cuminum cyminum L.) genotypes have been analyzed. Cryogenic grinding not only retains the volatiles but enhanced the recovery by 33.9 % in GC 4 and 43.5 % in RZ 209. A significant increase (29.9 %) over normal grinding in oil percentage was also observed in genotype RZ 209. This increase was, however, less (15.4 %) in genotype GC 4. Nineteen major compounds were identified in the essential oil of both genotypes. The two grinding techniques had significant effects on dependent variables, viz., volatile oil and monoterpenes. Cuminaldehyde was the main constituent in both genotypes, content of which increased from 48.2 to 56.1 % in GC 4 on cryo grinding. Content of terpines were found to decrease in cryo ground samples of GC 4 and either decrease or no change was found in RZ 209. Organoleptic test showed more pleasant aroma in cryo ground seeds of both the genotypes. Significant increase was also reported in fatty oil yield due to cryogenic grinding. Fatty acid methyl ester (FAME) analysis showed oleic acid as major FAME content of which increased from 88.1 to 94.9 % in RZ 209 and from 88.2 to 90.1 % in GC 4 on cryogenic grinding. Other prominent FAME were palmitic, palmitoleic and stearic acid. Results indicated commercial potential of cryogenic grinding technology for cumin in general and spices in particular for better retention of flavour and quality in spices.

  17. Co-grinding Effect on Crystalline Zaltoprofen with ?-cyclodextrin/Cucurbit[7]uril in Tablet Formulation

    OpenAIRE

    Li, Shanshan; Lin, Xiang; Xu, Kailin; He, Jiawei; Yang, Hongqin; Li, Hui

    2017-01-01

    This work aimed to investigate the co-grinding effects of ?-cyclodextrin (?-CD) and cucurbit[7]uril (CB[7]) on crystalline zaltoprofen (ZPF) in tablet formulation. Crystalline ZPF was prepared through anti-solvent recrystallization and fully analyzed through single-crystal X-ray diffraction. Co-ground dispersions and mono-ground ZPF were prepared using a ball grinding process. Results revealed that mono-ground ZPF slightly affected the solid state, solubility, and dissolution of crystalline Z...

  18. Next generation grinding spindle for cost-effective manufacture of advanced ceramic components

    Energy Technology Data Exchange (ETDEWEB)

    Kovach, J.A.; Laurich, M.A.

    2000-01-01

    Finish grinding of advanced structural ceramics has generally been considered an extremely slow and costly process. Recently, however, results from the High-Speed, Low-Damage (HSLD) program have clearly demonstrated that numerous finish-process performance benefits can be realized by grinding silicon nitride at high wheel speeds. A new, single-step, roughing-process capable of producing high-quality silicon nitride parts at high material removal rates while dramatically reducing finishing costs has been developed.

  19. Plastic deformation of particles of zirconium and titanium carbide subjected to vibration grinding

    Energy Technology Data Exchange (ETDEWEB)

    Kravchik, A.E.; Neshpor, V.S.; Savel' ev, G.A.; Ordan' yan, S.S.

    1976-12-01

    A study is made of the influence of stoichiometry on the characteristics of microplastic deformation in powders of zirconium and titanium carbide subjected to vibration grinding. The carbide powders were produced by direct synthesis from the pure materials: metallic titanium and zirconium and acetylene black. As to the nature of their elastic deformation, zirconium and titanium carbides can be considered elastic-isotropic materials. During vibration grinding, the primary fracture planes are the (110) planes. Carbides of nonstoichiometric composition are more brittle.

  20. Effect of electromagnetic radiation on the kinetics of grinding a mineral; Efecto de la radiacion electromagnetica en la cinetica de molienda de un mineral

    Energy Technology Data Exchange (ETDEWEB)

    Lopez M, A.; Delgadillo G, J. A. [Universidad Autonoma de San Luis Potosi, Instituto de Metalurgia, Av. Sierra Leona 550, 78210 San Luis Potosi (Mexico); Vega C, H. R., E-mail: alopezm6@yahoo.com.mx [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Cipres No. 10, Fracc. La Penuela, 98068 Zacatecas, Zac. (Mexico)

    2015-10-15

    In this study the effect of kinetic grinding of a mineral was investigated when is pre treated with ionizing electromagnetic radiation. This radiation is with 15 MeV photons produced by a Linac for Radiotherapy. The results for the irradiated sample with respect to the non-irradiated indicate that there were changes in the structure of the minerals in the sample under study. Changes were observed through scanning electron microscopy and X-ray diffraction, combined with the refinement of the diffraction profiles by the Rietveld method using the software Maud Program. The grinding kinetics shows a constant distribution of slightly greater size through time used for the irradiated sample. A reduction of 11.2% of the Bond (Wi) work index was reached, going from 10.91 to 9.69 kw h/t for the irradiated sample. This parameter represents the fracture toughness of a mineral. The results indicate greater efficiency of energy applied to the grinding of the irradiated sample with respect to the non-irradiated. (Author)

  1. Poly(ethylene glycol)s as grinding additives in the mechanochemical preparation of highly functionalized 3,5-disubstituted hydantoins.

    Science.gov (United States)

    Mascitti, Andrea; Lupacchini, Massimiliano; Guerra, Ruben; Taydakov, Ilya; Tonucci, Lucia; d'Alessandro, Nicola; Lamaty, Frederic; Martinez, Jean; Colacino, Evelina

    2017-01-01

    The mechanochemical preparation of highly functionalized 3,5-disubstituted hydantoins was investigated in the presence of various poly(ethylene) glycols (PEGs), as safe grinding assisting agents (liquid-assisted grinding, LAG). A comparative study under dry-grinding conditions was also performed. The results showed that the cyclization reaction was influenced by the amount of the PEG grinding agents. In general, cleaner reaction profiles were observed in the presence of PEGs, compared to dry-grinding procedures.

  2. Temperature prediction in high speed bone grinding using motor PWM signal.

    Science.gov (United States)

    Tai, Bruce L; Zhang, Lihui; Wang, Anthony C; Sullivan, Stephen; Wang, Guangjun; Shih, Albert J

    2013-10-01

    This research explores the feasibility of using motor electrical feedback to estimate temperature rise during a surgical bone grinding procedure. High-speed bone grinding is often used during skull base neurosurgery to remove cranial bone and approach skull base tumors through the nasal corridor. Grinding-induced heat could propagate and potentially injure surrounding nerves and arteries, and therefore, predicting the temperature in the grinding region would benefit neurosurgeons during the operation. High-speed electric motors are controlled by pulse-width-modulation (PWM) to alter the current input and thus maintain the rotational speed. Assuming full mechanical to thermal power conversion in the grinding process, PWM can be used as feedback for heat generation and temperature prediction. In this study, the conversion model was established from experiments under a variety of grinding conditions and an inverse heat transfer method to determine heat flux. Given a constant rotational speed, the heat conversion was represented by a linear function, and could predict temperature from the experimental data with less than 20% errors. Such results support the advance of this technology for practical application. Copyright © 2013 IPEM. Published by Elsevier Ltd. All rights reserved.

  3. Multiobjective Optimization of ELID Grinding Process Using Grey Relational Analysis Coupled with Principal Component Analysis

    Directory of Open Access Journals (Sweden)

    S. Prabhu

    2014-06-01

    Full Text Available Carbon nanotube (CNT mixed grinding wheel has been used in the electrolytic in-process dressing (ELID grinding process to analyze the surface characteristics of AISI D2 Tool steel material. CNT grinding wheel is having an excellent thermal conductivity and good mechanical property which is used to improve the surface finish of the work piece. The multiobjective optimization of grey relational analysis coupled with principal component analysis has been used to optimize the process parameters of ELID grinding process. Based on the Taguchi design of experiments, an L9 orthogonal array table was chosen for the experiments. The confirmation experiment verifies the proposed that grey-based Taguchi method has the ability to find out the optimal process parameters with multiple quality characteristics of surface roughness and metal removal rate. Analysis of variance (ANOVA has been used to verify and validate the model. Empirical model for the prediction of output parameters has been developed using regression analysis and the results were compared for with and without using CNT grinding wheel in ELID grinding process.

  4. Analysis and Compensation for Gear Accuracy with Setting Error in Form Grinding

    Directory of Open Access Journals (Sweden)

    Chenggang Fang

    2015-01-01

    Full Text Available In the process of form grinding, gear setting error was the main factor that influenced the form grinding accuracy; we proposed an effective method to improve form grinding accuracy that corrected the error by controlling the machine operations. Based on establishing the geometry model of form grinding and representing the gear setting errors as homogeneous coordinate, tooth mathematic model was obtained and simplified under the gear setting error. Then, according to the gear standard of ISO1328-1: 1997 and the ANSI/AGMA 2015-1-A01: 2002, the relationship was investigated by changing the gear setting errors with respect to tooth profile deviation, helix deviation, and cumulative pitch deviation, respectively, under the condition of gear eccentricity error, gear inclination error, and gear resultant error. An error compensation method was proposed based on solving sensitivity coefficient matrix of setting error in a five-axis CNC form grinding machine; simulation and experimental results demonstrated that the method can effectively correct the gear setting error, as well as further improving the forming grinding accuracy.

  5. Virtual sensors for on-line wheel wear and part roughness measurement in the grinding process.

    Science.gov (United States)

    Arriandiaga, Ander; Portillo, Eva; Sánchez, Jose A; Cabanes, Itziar; Pombo, Iñigo

    2014-05-19

    Grinding is an advanced machining process for the manufacturing of valuable complex and accurate parts for high added value sectors such as aerospace, wind generation, etc. Due to the extremely severe conditions inside grinding machines, critical process variables such as part surface finish or grinding wheel wear cannot be easily and cheaply measured on-line. In this paper a virtual sensor for on-line monitoring of those variables is presented. The sensor is based on the modelling ability of Artificial Neural Networks (ANNs) for stochastic and non-linear processes such as grinding; the selected architecture is the Layer-Recurrent neural network. The sensor makes use of the relation between the variables to be measured and power consumption in the wheel spindle, which can be easily measured. A sensor calibration methodology is presented, and the levels of error that can be expected are discussed. Validation of the new sensor is carried out by comparing the sensor's results with actual measurements carried out in an industrial grinding machine. Results show excellent estimation performance for both wheel wear and surface roughness. In the case of wheel wear, the absolute error is within the range of microns (average value 32 μm). In the case of surface finish, the absolute error is well below Ra 1 μm (average value 0.32 μm). The present approach can be easily generalized to other grinding operations.

  6. The effects of pf grind quality on coal burnout in a 1 MW combustion test facility

    Energy Technology Data Exchange (ETDEWEB)

    Richelieu Barranco; Michael Colechin; Michael Cloke; Will Gibb; Edward Lester [University of Nottingham, Nottingham (United Kingdom). School of Chemical, Environmental and Mining Engineering, Nottingham Fuel and Energy Centre

    2006-05-15

    A study was carried out to determine the effect of pf particle size distribution on coal burnout propensity in a 1 MW pulverised fuel burner. The specific aim of the work was to assess the improvement in combustion performance achievable by retrofitting commercially available high performance static or dynamic classifiers to existing plants. Two coals were used and were selected as representative of extremes in fuel characteristics experienced by coal importing utilities in Europe. Each coal was fired in the unit at a range of grind sizes to determine the overall impact of a variable performance from a mill. The levels of unburnt carbon in the resultant flyashes for the two coals showed significantly different behaviour. For the higher volatile coal, the unburnt carbon was found to be insensitive to grind quality. However, the coarser grinds of the other coal produced significantly lower unburnt carbon than expected when compared with the finest grinds. Generally the results indicate that the installation of improved classification technology, leading to a finer product, will help to lower unburnt carbon levels. Nevertheless, further work will be necessary to establish the levels of diminishing returns for grind size, burnout performance and grind costs. 21 refs., 4 figs., 4 tabs.

  7. Numerical Simulation of a Grinding Process Model for the Spatial Work-pieces: Development of Modeling Techniques

    Directory of Open Access Journals (Sweden)

    S. A. Voronov

    2015-01-01

    Full Text Available The article presents a literature review in simulation of grinding processes. It takes into consideration the statistical, energy based, and imitation approaches to simulation of grinding forces. Main stages of interaction between abrasive grains and machined surface are shown. The article describes main approaches to the geometry modeling of forming new surfaces when grinding. The review of approaches to the chip and pile up effect numerical modeling is shown. Advantages and disadvantages of grain-to-surface interaction by means of finite element method and molecular dynamics method are considered. The article points out that it is necessary to take into consideration the system dynamics and its effect on the finished surface. Structure of the complex imitation model of grinding process dynamics for flexible work-pieces with spatial surface geometry is proposed from the literature review. The proposed model of spatial grinding includes the model of work-piece dynamics, model of grinding wheel dynamics, phenomenological model of grinding forces based on 3D geometry modeling algorithm. Model gives the following results for spatial grinding process: vibration of machining part and grinding wheel, machined surface geometry, static deflection of the surface and grinding forces under various cutting conditions.

  8. Dry-grind processing using amylase corn and superior yeast to reduce the exogenous enzyme requirements in bioethanol production.

    Science.gov (United States)

    Kumar, Deepak; Singh, Vijay

    2016-01-01

    Conventional corn dry-grind ethanol production process requires exogenous alpha and glucoamylases enzymes to breakdown starch into glucose, which is fermented to ethanol by yeast. This study evaluates the potential use of new genetically engineered corn and yeast, which can eliminate or minimize the use of these external enzymes, improve the economics and process efficiencies, and simplify the process. An approach of in situ ethanol removal during fermentation was also investigated for its potential to improve the efficiency of high-solid fermentation, which can significantly reduce the downstream ethanol and co-product recovery cost. The fermentation of amylase corn (producing endogenous α-amylase) using conventional yeast and no addition of exogenous α-amylase resulted in ethanol concentration of 4.1 % higher compared to control treatment (conventional corn using exogenous α-amylase). Conventional corn processed with exogenous α-amylase and superior yeast (producing glucoamylase or GA) with no exogenous glucoamylase addition resulted in ethanol concentration similar to control treatment (conventional yeast with exogenous glucoamylase addition). Combination of amylase corn and superior yeast required only 25 % of recommended glucoamylase dose to complete fermentation and achieve ethanol concentration and yield similar to control treatment (conventional corn with exogenous α-amylase, conventional yeast with exogenous glucoamylase). Use of superior yeast with 50 % GA addition resulted in similar increases in yield for conventional or amylase corn of approximately 7 % compared to that of control treatment. Combination of amylase corn, superior yeast, and in situ ethanol removal resulted in a process that allowed complete fermentation of 40 % slurry solids with only 50 % of exogenous GA enzyme requirements and 64.6 % higher ethanol yield compared to that of conventional process. Use of amylase corn and superior yeast in the dry-grind processing industry

  9. Analysing a Relationship Between Wheel Wear and Cutting Forces During Diamond Grinding

    Directory of Open Access Journals (Sweden)

    M. A. Shavva

    2014-01-01

    Full Text Available In diamond grinding cutting forces affect the quality of the machined surface. We can estimate a wear rate of the diamond wheel by the magnitude of the forces and promptly resort to the restoration of its cutting properties. To solve this problem it is necessary to define a relationship between grinding wheel wear and cutting forces. There was no this dependence found in the sources of literature.The forces acting on a single worn diamond grain are considered to find the relationship between wheel wear and cutting forces. The main forces acting on the diamond grain are such as a reaction force of machining material, a frictional force over a worn place of the grain, and a total pressure on the contact surface of the grain and machining material. According to calculation results, in grinding the cutting forces are proportional to the hardness of machining material, and depend on the grain wear, as well as on the process operation conditions.The paper presents a technique for calculating the number of cutting (active grains per unit surface of diamond wheel to determine a total cutting force in grinding. The number of cutting grains depends on the properties of diamond wheel and on the operation conditions of grinding process.During grinding a total cutting force is calculated through the single grain cutting force, the number of cutting grains per unit surface of the grinding wheel and the contact area between the wheel and the work piece. Theoretical calculation of the forces is based on the condition that protrusions of all cutting grains are identical and all grains have a maximum wear, i.e. maximum worn place of grain.Calculations based on proposed theoretical formulas are compared with the calculations from the empirical formulas given in the literature. Varying the operation conditions of grinding makes the comparison. Convergence of results in the range of 5-20% is regarded as acceptable.On the BMSTU base flat diamond grinding of tungsten

  10. The Effect of Wood Alignment on Wood Grinding – Part 1: Properties of Pulp and Fines Revealed in the Grinding Mechanism

    Directory of Open Access Journals (Sweden)

    Erkki Tapani Saharinen

    2016-03-01

    Full Text Available In industrial wood grinding, logs are pressed against a rotating stone, with the logs and fiber axis parallel to the axis of the stone. The objective of this study is to clarify how the wood alignment affects the process and pulp properties. In this research, wood blocks were fed into a laboratory grinder with various alignments in relation to the surface of the grinding stone. The effects of the alignment on the properties of the pulp and the amount and quality of fines were measured. A grinding mechanism was proposed. The results show that the pulp quality is very sensitive to the angle between the stone surface and the log. In gentle refining, the fiber structure is loosened by fatigue before it is bent on the surface; pressure pulses produce fibrillar material, and fibers develop toward having good bonding ability. In forced grinding, the process is “violent”, and the fiber wears and becomes crushed immediately on the surface into small particles with low bonding ability.

  11. Determination of rational parameters for process of grinding materials pre-crushed by pressure in ball mill

    Science.gov (United States)

    Romanovich, A. A.; Romanovich, L. G.; Chekhovskoy, E. I.

    2018-03-01

    The article presents the results of experimental studies on the grinding process of a clinker preliminarily ground in press roller mills in a ball mill equipped with energy exchange devices. The authors studied the influence of the coefficients of loading for grinding bodies of the first and second mill chambers, their lengths, angles of inclination, and the mutual location of energy exchange devices (the ellipse segment and the double-acting blade) on the output parameters of the grinding process (productivity, drive power consumption and specific energy consumption). It is clarified that the best results of the disaggregation and grinding process, judging by the minimum specific energy consumption in the grinding of clinker with an anisotropic texture after force deformation between the rolls of a press roller shredder, are achieved at a certain angle of ellipse segment inclination; the length of the first chamber and the coefficients of loading the chambers with grinding bodies.

  12. Deep frying

    NARCIS (Netherlands)

    Koerten, van K.N.

    2016-01-01

    Deep frying is one of the most used methods in the food processing industry. Though practically any food can be fried, French fries are probably the most well-known deep fried products. The popularity of French fries stems from their unique taste and texture, a crispy outside with a mealy soft

  13. Deep learning

    CERN Document Server

    Goodfellow, Ian; Courville, Aaron

    2016-01-01

    Deep learning is a form of machine learning that enables computers to learn from experience and understand the world in terms of a hierarchy of concepts. Because the computer gathers knowledge from experience, there is no need for a human computer operator to formally specify all the knowledge that the computer needs. The hierarchy of concepts allows the computer to learn complicated concepts by building them out of simpler ones; a graph of these hierarchies would be many layers deep. This book introduces a broad range of topics in deep learning. The text offers mathematical and conceptual background, covering relevant concepts in linear algebra, probability theory and information theory, numerical computation, and machine learning. It describes deep learning techniques used by practitioners in industry, including deep feedforward networks, regularization, optimization algorithms, convolutional networks, sequence modeling, and practical methodology; and it surveys such applications as natural language proces...

  14. The project and technical study on the track of vertical axis linkage abrasive belt grinding of turbine blade

    International Nuclear Information System (INIS)

    Ma Yujian; Tang Xiaoqi; Chen Jihong; Yang Jianzhong

    2010-01-01

    A method of CNC turbine blade profile abrasive belt grinding is introduced based on optimum grinding effect, where the direction of the axis of trolley wheel is consistent with that of minimum principal curvature on the contact point of turbine blade. And the cutter location path is determined, and then the NC code is derived from post-processing. A virtual machine model is built in VERICUT software to simulate actual grinding process and applied in practice, which yielded satisfactory results. (authors)

  15. Effect of simulated chairside grinding procedures using commercially available abrasive agents on the surface properties of zirconia.

    Science.gov (United States)

    Sandhu, Ramandeep; Kheur, Mohit; Kheur, Supriya

    2017-01-01

    The aim of the present study was to assess the change in physical properties (surface roughness, surface hardness and phase transformation) after surface grinding of zirconia by using three commercially available abrasives. Thirty sintered zirconia specimens were prepared and divided into three groups namely Group M (grinded using Mani Dia diamond bur standard grit), Group T (grinded using Tri Hawk diamond bur coarse grit) and Group P (grinded using Predator carbide bur). A customised assembly was used to follow a standardised protocol for surface grinding. The surface roughness, surface hardness and phase transformation was recorded before and after the grinding procedure. ANOVA and Bonferroni post hoc test were used to assess the values obtained after the testing the surface roughness and surface hardness. The results of the present study revealed the average values of change in surface roughness as Group M (0.44 μ m) and Group T (1.235 μ m) and Group P (-0.88 μ m). The average values of change in surface hardness were Group T (19.578 HV), Group M (46.722 HV) and Group P (36.429 HV). The change in surface hardness was not statistically significant. There was no phase transformation seen after the grinding procedure. Carbide burs along with copious water irrigation when used to grind zirconia intra-orally produces has a polishing effect, minimal change in hardness & no phase transformation. The present study advocates the use of carbides for chair-side grinding of zirconia.

  16. The Effect of Wood Alignment on Wood Grinding – Part 2: Fines Character and Microscopic Observations

    Directory of Open Access Journals (Sweden)

    Sabine Heinemann

    2016-01-01

    Full Text Available During industrial wood grinding, logs are pressed against a rotating stone, with the logs and fibre axes parallel to the axis of the stone. For this study, wood blocks were fed into a laboratory grinder with various alignments in relation to the surface of the grinding stone. The effects of the alignment on the properties of the pulp, the amount, and the quality of the fines were measured, and a grinding mechanism is proposed. In this paper, the obtained results showed that the pulp quality was highly sensitive to the angle between the stone surface and the log, and different for fatigue-based and force-based grinding. The tests were observed using microscopic techniques and discussed in terms of fines amount and fines quality. In gentle refining, the fibre structure is loosened by fatigue before it is bent on the surface, pressure pulses produce fibrillar material, and fibres develop good bonding ability. In forced grinding, the process is “violent” and the fibre wears and is crushed immediately on the surface into small particles with low bonding ability.

  17. Modification of surface texture by grinding and polishing lead zirconate titanate ceramics

    International Nuclear Information System (INIS)

    Cheng, S.; Lloyd, I.K.

    1992-01-01

    This paper reports that grinding and polishing affected the orientation of 90 degrees domains at the surface of lead zirconate titanate (PZT) ceramics. This was quantified by using changes in the intensity ratio of the (002) and (200) X-ray reflections. Grinding unpoled PZT with 600-grit SiC paper gave X-ray intensity ratios similar to those of poled material. This implies that 90 degrees domain realignments had occurred in the near surface region probed by the X-rays. Grinding poled samples with 600-grit SiC further increased the X-ray intensity ratio beyond that caused by poling, indicating that additional surface reorientation of 90 degrees domains had occurred. The effects of diamond polishing depended on the size of the diamond particles. The use of 6-μm diamond had no effect on the (002)/(200) intensity ratio of either poled or unpoled samples, while polishing with 15- or 45-μm diamond significantly enhanced the 90 degrees domain rotation. In unpoled samples, the increase in the X-ray intensity ratio then approached that induced by poling or grinding with 600-grit SiC paper. While the observed increase in X-ray intensity ratio upon grinding is attributed to the rotation of 90 degrees domains, the simultaneous formation of 180 degrees domains appears to minimize or reduce the increase in electrical polarization

  18. Effect of Grinding on Chrysotile, Amosite and Crocidolite and Implications for Thermal Treatment

    Directory of Open Access Journals (Sweden)

    Andrea Bloise

    2018-03-01

    Full Text Available Nowadays, due to the adverse health effects associated with exposure to asbestos, its inertization is one of the most important issues of waste risk management. Based on the research line of mechano-chemical and thermal treatment of asbestos containing materials, the aim of this study was to examine the effects of dry grinding on the structure, temperature stability and fibre size of chrysotile from Balangero (Italy, as well as standard UICC (Union for International Cancer Control amosite and standard UICC (Union for International Cancer Control crocidolite. Dry grinding was accomplished in an eccentric vibration mill by varying the grinding time (30 s, 5 and 10 min. Results show a decrease in crystallinity, the formation of lattice defects and size reduction with progressive formation of agglomerates in the samples after the mechanical treatment. Transmission electron microscopy (TEM results show that the final product obtained after 10 min of grinding is composed of non-crystalline particles and a minor residue of crystalline fibres that are not regulated because they do not meet the size criteria for a regulated fibre. Grinding results in a decrease of temperature and enthalpy of dehydroxylation (ΔHdehy of chrysotile, amosite and crocidolite. This permits us to completely destroy these fibres in thermal inertization processes using a lower net thermal energy than that used for the raw samples.

  19. Westinghouse Modular Grinding Process - Enhancement of Volume Reduction for Hot Resin Supercompaction - 13491

    Energy Technology Data Exchange (ETDEWEB)

    Fehrmann, Henning [Westinghouse Electric Germany GmbH, Dudenstr. 44, D-68167 Mannheim (Germany); Aign, Joerg [Westinghouse Electric Germany GmbH, Global D and D and Waste Management, Tarpenring 6, D-22419 Hamburg (Germany)

    2013-07-01

    In nuclear power plants (NPP) ion exchange (IX) resins are used in several systems for water treatment. Spent resins can contain a significant amount of contaminates which makes treatment for disposal of spent resins mandatory. Several treatment processes are available such as direct immobilization with technologies like cementation, bitumisation, polymer solidification or usage of a high integrity container (HIC). These technologies usually come with a significant increase in final waste volume. The Hot Resin Supercompaction (HRSC) is a thermal treatment process which reduces the resin waste volume significantly. For a mixture of powdered and bead resins the HRSC process has demonstrated a volume reduction of up to 75 % [1]. For bead resins only the HRSC process is challenging because the bead resins compaction properties are unfavorable. The bead resin material does not form a solid block after compaction and shows a high spring back effect. The volume reduction of bead resins is not as good as for the mixture described in [1]. The compaction properties of bead resin waste can be significantly improved by grinding the beads to powder. The grinding also eliminates the need for a powder additive.Westinghouse has developed a modular grinding process to grind the bead resin to powder. The developed process requires no circulation of resins and enables a selective adjustment of particle size and distribution to achieve optimal results in the HRSC or in any other following process. A special grinding tool setup is use to minimize maintenance and radiation exposure to personnel. (authors)

  20. Simulation and experimental investigation of inner-jet electrochemical grinding of GH4169 alloy

    Directory of Open Access Journals (Sweden)

    Hansong LI

    2018-03-01

    Full Text Available GH4169 alloy is one of the most commonly used materials in aero engine turbine blades, but its machinability is poor because of its excellent strength at high temperatures. Electrochemical machining (ECM has become a common method for machining this alloy and other difficult-to-machine materials. Electrochemical grinding (ECG is a hybrid process combining ECM and conventional grinding. In this paper, investigations conducted on inner-jet ECG of GH4169 alloy are described. Two types of inner-jet ECG grinding wheels were used to machine a flat bottom surface. The machining process was simulated using COMSOL software, and machining gaps under different machining parameters were obtained. In addition, maximum feed rates and maximum material removal rates under different machining parameters were studied experimentally. The maximum sizes and the uniformity of the distributions of the gaps machined by the two grinding wheels were compared. The effects of different applied voltages on the machining results were also investigated. Keywords: Electrochemical grinding, GH4169 alloy, Inner-jet, Material removal rate, Maximum feed rate

  1. Reliable Mechanochemistry: Protocols for Reproducible Outcomes of Neat and Liquid Assisted Ball-mill Grinding Experiments.

    Science.gov (United States)

    Belenguer, Ana M; Lampronti, Giulio I; Sanders, Jeremy K M

    2018-01-23

    The equilibrium outcomes of ball mill grinding can dramatically change as a function of even tiny variations in the experimental conditions such as the presence of very small amounts of added solvent. To reproducibly and accurately capture this sensitivity, the experimentalist needs to carefully consider every single factor that can affect the ball mill grinding reaction under investigation, from ensuring the grinding jars are clean and dry before use, to accurately adding the stoichiometry of the starting materials, to validating that the delivery of solvent volume is accurate, to ensuring that the interaction between the solvent and the powder is well understood and, if necessary, a specific soaking time is added to the procedure. Preliminary kinetic studies are essential to determine the necessary milling time to achieve equilibrium. Only then can exquisite phase composition curves be obtained as a function of the solvent concentration under ball mill liquid assisted grinding (LAG). By using strict and careful procedures analogous to the ones here presented, such milling equilibrium curves can be obtained for virtually all milling systems. The system we use to demonstrate these procedures is a disulfide exchange reaction starting from the equimolar mixture of two homodimers to obtain at equilibrium quantitative heterodimer. The latter is formed by ball mill grinding as two different polymorphs, Form A and Form B. The ratio R = [Form B] / ([Form A] + [Form B]) at milling equilibrium depends on the nature and concentration of the solvent in the milling jar.

  2. Dead time and recovery time investigations on grinding plants with the aid of radioisotopes

    Energy Technology Data Exchange (ETDEWEB)

    Roetzer, H; Hagspiel, W

    1977-02-01

    With the aid of the radionuclides Mn 56 and Na 24 as tracers, respectively, the following characteristics were investigated for a roller mill and for a tandem air-swept grinding plant: the time of passage of the mill feed material, the retention time distribution in the grinding system (most frequent and mean retention time), and the time required for, respectively, 50%, 90% and 95% of the material to pass, in some instances separately for the three raw material components limestone, clay and sand. In addition, in the case of the air-swept grinding plant the time required for conveying the raw meal sample from the sampling point to the X-ray fluorescence analysis apparatus was determined. The mean retention time of the material in the two roller mills IV and V was 2.93 and 2.55 minutes respectively; for the tandem air-swept grinding plant it was 8 minutes. The time taken for 90% of the mill feed to pass through the mill was 5.5 and 5 minutes for the roller mills respectively and was about 18.3 minutes for the air-swept plant. The dead time vor conveying the raw meal sample to the X-ray fluorescence apparatus, including further grinding of the sample in a vibratory mill, was 12 minutes.

  3. Occlusal splints for treating sleep bruxism (tooth grinding).

    Science.gov (United States)

    Macedo, C R; Silva, A B; Machado, M A; Saconato, H; Prado, G F

    2007-10-17

    Sleep bruxism is an oral activity characterised by teeth grinding or clenching during sleep. Several treatments for sleep bruxism have been proposed such as pharmacological, psychological, and dental. To evaluate the effectiveness of occlusal splints for the treatment of sleep bruxism with alternative interventions, placebo or no treatment. We searched the Cochrane Oral Health Group's Trials Register (to May 2007); the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2007, Issue 1); MEDLINE (1966 to May 2007); EMBASE (1980 to May 2007); LILACS (1982 to May 2007); Biblioteca Brasileira de Odontologia (1982 to May 2007); Dissertation, Theses and Abstracts (1981 to May 2007); and handsearched abstracts of particular importance to this review. Additional reports were identified from the reference lists of retrieved reports and from article reviews about treating sleep bruxism. There were no language restrictions. We selected randomised or quasi-randomised controlled trials (RCTs), in which splint therapy was compared concurrently to no treatment, other occlusal appliances, or any other intervention in participants with sleep bruxism. Data extraction was carried out independently and in duplicate. Validity assessment of the included trials was carried out at the same time as data extraction. Discrepancies were discussed and a third review author consulted. The author of the primary study was contacted when necessary. Thirty-two potentially relevant RCTs were identified. Twenty-four trials were excluded. Five RCTs were included. Occlusal splint was compared to: palatal splint, mandibular advancement device, transcutaneous electric nerve stimulation, and no treatment. There was just one common outcome (arousal index) which was combined in a meta-analysis. No statistically significant differences between the occlusal splint and control groups were found in the meta-analyses. There is not sufficient evidence to state that the occlusal splint is

  4. Application of focus-variation Technique in Measurements of Ultrasonic Vibrations of Grinding pins

    Directory of Open Access Journals (Sweden)

    Wdowik Roman

    2015-01-01

    Full Text Available The paper presents the application of focus-variation technique in measurements of ultrasonic vibrations of grinding pins. Ultrasonic vibrations of tools are applied in ultrasonic assisted grinding. Their measurements are significant for development of this hybrid machining process. Alumina and zirconia ceramic materials in the final fired state were machined in experiments which are known as scratch tests. Diamond grinding pin was used as a tool to machine scratches. Marks of diamond grains, left on the surface of workpieces after machining process, were investigated using The Infinite Focus Real 3D optical microscope. Focus-variation is the principle of operation of this microscope. Investigations concerned possibilities of measurements of an amplitude of axial and radial vibrations in the case of two ceramic materials. Results of performed measurements are presented and discussed for selected machining parameters.

  5. Reducing the Edge Chipping for Capillary End Face Grinding and Polishing

    Directory of Open Access Journals (Sweden)

    Hošek J.

    2013-05-01

    Full Text Available This paper presents results of glass capillary end face grinding and polishing by approach that reduces the edge chipping. Brittle materials have natural tendency for edge chipping what leads to beveling the sharp edges. Not beveled sharp edges on glass capillary are important for special applications like surface tension measurement of small liquid samples. We use common grinding and polishing process for capillary end face machining modified with gradual decreasing of grinding load based on the relation of the critical chipping load. Achieved surface roughness is measured using atomic force microscopy (AFM. Capillary inner edge quality is checked both with optical microscopes and electron microscope too. We achieved a non-chipped capillary inner edge with radius down to 100 nm.

  6. Extraction of Lithium from Lepidolite Using Mixed Grinding with Sodium Sulfide Followed by Water Leaching

    Directory of Open Access Journals (Sweden)

    Jaeryeong Lee

    2015-11-01

    Full Text Available Mixed grinding with Na2S followed by water leaching was performed to extract Li from lepidolite. The leachability of Li increases dramatically in the ground mixture, regardless of the mixing ratio over the range of 1:1 to 3:1, while only 4.53% of Li was extracted in lepidolite ground without Na2S. The leachability increased with an increase of the grinding time, and ultimately, 93% of the Li was leached by water from the ground mixture with a weight ratio of 3:1 (Na2S:Lepidolite. In the process of the mixed grinding, the Li-contained lepidolite was destructured crystallographically, and it might have changed to different compounds. This process enables us to extract Li from lepidolite via a water leaching treatment.

  7. Improved coal grinding and fuel flow control in thermal power plants

    DEFF Research Database (Denmark)

    Niemczyk, Piotr; Bendtsen, Jan Dimon

    2011-01-01

    A novel controller for coal circulation and pulverized coal flow in a coal mill is proposed. The design is based on optimal control theory for bilinear systems with additional integral action. The states are estimated from the grinding power consumption and the amount of coal accumulated in the m......A novel controller for coal circulation and pulverized coal flow in a coal mill is proposed. The design is based on optimal control theory for bilinear systems with additional integral action. The states are estimated from the grinding power consumption and the amount of coal accumulated...... as well as when parameter uncertainties and noise are present. The proposed controller lowers the grinding power consumption while in most cases exhibiting superior performance in comparison with the PID controller....

  8. Sparking-out optimization while surface grinding aluminum alloy 1933T2 parts using fuzzy logic

    Science.gov (United States)

    Soler, Ya I.; Salov, V. M.; Kien Nguyen, Chi

    2018-03-01

    The article presents the results of a search for optimal sparing-out strokes when surface grinding aluminum parts by high-porous wheels Norton of black silicon carbide 37C80K12VP using fuzzy logic. The topography of grinded surface is evaluated according to the following parameters: roughness – Ra, Rmax, Sm; indicators of flatness deviation – EFEmax, EFEa, EFEq; microhardness HV, each of these parameters is represented by two measures of position and dispersion. The simulation results of fuzzy logic in the Matlab medium establish that during the grinding of alloy 1933T2, the best integral performance evaluation of sparking-out was given to two double-strokes (d=0.827) and the worst – to three ones (d=0.405).

  9. Numerical and experimental validation of a particle Galerkin method for metal grinding simulation

    Science.gov (United States)

    Wu, C. T.; Bui, Tinh Quoc; Wu, Youcai; Luo, Tzui-Liang; Wang, Morris; Liao, Chien-Chih; Chen, Pei-Yin; Lai, Yu-Sheng

    2018-03-01

    In this paper, a numerical approach with an experimental validation is introduced for modelling high-speed metal grinding processes in 6061-T6 aluminum alloys. The derivation of the present numerical method starts with an establishment of a stabilized particle Galerkin approximation. A non-residual penalty term from strain smoothing is introduced as a means of stabilizing the particle Galerkin method. Additionally, second-order strain gradients are introduced to the penalized functional for the regularization of damage-induced strain localization problem. To handle the severe deformation in metal grinding simulation, an adaptive anisotropic Lagrangian kernel is employed. Finally, the formulation incorporates a bond-based failure criterion to bypass the prospective spurious damage growth issues in material failure and cutting debris simulation. A three-dimensional metal grinding problem is analyzed and compared with the experimental results to demonstrate the effectiveness and accuracy of the proposed numerical approach.

  10. Online monitoring of a belt grinding process by using a light scattering method

    International Nuclear Information System (INIS)

    Boehm, Johannes; Vernes, Andras; Vorlaufer, Georg; Vellekoop, Michael

    2010-01-01

    Industrially ground surfaces often have a characteristic surface topography known as chatter marks. The surface finishing is mainly monitored by optical measurement techniques. In this work, the monitoring of an industrial belt grinding process with a light scattering sensor is presented. Although this technique is primarily applied for parametric surface roughness analysis, here it is shown that it enables also the measurement of the surface topography, i.e., the chatter marks occurring during the belt grinding process. In particular, it is proven that the light scattering method is appropriate to measure online the topography of chatter marks. Furthermore, the frequency analysis of the data reveals that the wavelength of chatter marks strongly depends on process parameters, such as the grinding speed.

  11. Microwave-assisted grinding of metallurgical coke; Molienda asistida con microondas de un coque metalurgico

    Energy Technology Data Exchange (ETDEWEB)

    Ruisanchez, E.; Juarez-Perez, E. J.; Arenillas, A.; Bermudez, J. M.; Menendez, J. A.

    2014-10-01

    Metallurgical cokes are composed of graphitic carbon (s2p2) and different inorganic compounds with very different capacities to absorb microwave radiation. Moreover, due to the electric conductivity shown by the metallurgical cokes, microwave radiation produces electric arcs or microplasmas, which gives rise to hot spots. Therefore, when these cokes are irradiated with microwaves some parts of the particle experiment a rapid heating, while some others do not heat at all. As a result of the different expansion and stress caused by thermal the shock, small cracks and micro-fissures are produced in the particle. The weakening of the coke particles, and therefore an improvement of its grind ability, is produced. This paper studies the microwave-assisted grinding of metallurgical coke and evaluates the grinding improvement and energy saving. (Author)

  12. Investigation of the milling capabilities of the F10 Fine Grind mill using Box-Behnken designs.

    Science.gov (United States)

    Tan, Bernice Mei Jin; Tay, Justin Yong Soon; Wong, Poh Mun; Chan, Lai Wah; Heng, Paul Wan Sia

    2015-01-01

    Size reduction or milling of the active is often the first processing step in the design of a dosage form. The ability of a mill to convert coarse crystals into the target size and size distribution efficiently is highly desirable as the quality of the final pharmaceutical product after processing is often still dependent on the dimensional attributes of its component constituents. The F10 Fine Grind mill is a mechanical impact mill designed to produce unimodal mid-size particles by utilizing a single-pass two-stage size reduction process for fine grinding of raw materials needed in secondary processing. Box-Behnken designs were used to investigate the effects of various mill variables (impeller, blower and feeder speeds and screen aperture size) on the milling of coarse crystals. Response variables included the particle size parameters (D10, D50 and D90), span and milling rate. Milled particles in the size range of 5-200 μm, with D50 ranging from 15 to 60 μm, were produced. The impeller and feeder speeds were the most critical factors influencing the particle size and milling rate, respectively. Size distributions of milled particles were better described by their goodness-of-fit to a log-normal distribution (i.e. unimodality) rather than span. Milled particles with symmetrical unimodal distributions were obtained when the screen aperture size was close to the median diameter of coarse particles employed. The capacity for high throughput milling of particles to a mid-size range, which is intermediate between conventional mechanical impact mills and air jet mills, was demonstrated in the F10 mill. Prediction models from the Box-Behnken designs will aid in providing a better guide to the milling process and milled product characteristics. Copyright © 2014 Elsevier B.V. All rights reserved.

  13. THE INFLUENCE OF JOINT GRINDING OF CEMENT AND COOPER SLAG ON MORTAR PROPERTIES

    Directory of Open Access Journals (Sweden)

    Kravtsov Aleksey Vladimirovich

    2016-08-01

    Full Text Available The problem of applying copper manufacturing waste locating in the Chelyabinsk region as a component of mixed is considered in this article. Application of mixed binder with superplasticizers, based on esters with carboxyl groups, have not sufficiently been studied by the present time due to the diversity of species and complexity of the chemical structure. This trend is current for today’s science because of the growing rates and scales of building production, in particular, of concrete works. Copper slag dumps located in the Ural Federal district haven’t been widely used in building production or in other industrial production by the present time. Efficient utilization of copper production waste materials will help to solve ecological problems in many regions of Russia. Structure formation period of cement stone based on mixed binder made of Portland cement and granulated cooper slag with application of superplasticizer is studied in the article. The authors present a thermal variation diagram of mortar based on mixed binder made of Portland cement and granulated cooper slag in the process of 21 hours of hardening under normal conditions and the results of ultrasound investigation of concrete structure formation period during 5 hours of hardening. The strength development process diagram of mortar based on mixed binder made of Portland cement and granulated cooper slag for 28 days of hardening under normal conditions and the research results of the compressive strength of concrete samples are shown in this article. The obtained characteristics don’t confirm the prospects of applying joint grinding for mortar with the observed kind of non-ferrous metallurgy waste. Also, the obtained results allow us to make a conclusion about little advantages of using this method of binder production. Copper slag can be more effectively used as a component of complex organic and mineral admixture for building production with different purposes and fields

  14. Co-contraction behaviour of masticatory and neck muscles during tooth grinding.

    Science.gov (United States)

    Giannakopoulos, N N; Schindler, H J; Hellmann, D

    2018-07-01

    The objective of this study was to analyse the co-contraction behaviour of jaw and neck muscles during force-controlled experimental grinding in the supine position. Twelve symptom-free subjects were enrolled in the experimental study. Electromyographic (EMG) activity of semispinalis capitis, splenius capitis and levator scapulae muscles was recorded bilaterally with intramuscular fine-wire electrodes, whereas that of sternocleidomastoideus, infrahyoidal, suprahyoidal, masseter and anterior temporalis muscles were registered with surface electrodes. EMG and force measurements were performed during tasks simulating tooth grinding on custom-made intraoral metal splints. The mean EMG activity normalised by maximum voluntary contraction (% MVC) of each of the neck muscles studied during grinding was analysed and compared with previous data from jaw clenching at identical force (100 N) and (supine) position. The occurrence of low-level, long-lasting tonic activation (LLTA) of motor units was also documented. The mean three-dimensional force vector of the grinding forces was 106 ± 74 N. In the frontal plane, the incline to the midsagittal plane ranged between 10° and 15°. In the midsagittal plane, the incline to the frontal plane was negligibly small. Posterior neck muscle activity during grinding ranged between 4.5% and 12% MVC and during clenching with 100 N between 1.8% and 9.9% MVC. Masticatory muscle activity during grinding ranged between 17% and 21% MVC for contralateral masseter and ipsilateral temporalis and between 4% and 6.5% for ipsilateral masseter and contralateral temporalis. LLTA had an average duration of 195 ± 10 seconds. The findings from this study do not support pathophysiological muscle chain theories postulating simple biomechanical coupling of neck and jaw muscles. Co-contractions of neck and masticatory muscles may instead occur as a result of complex neurophysiological interactions. © 2018 John Wiley & Sons Ltd.

  15. An efficient and green method for regio- and chemo-selective Friedel–Crafts acylations using a deep eutectic mixture ([CholineCl][ZnCl2]3)

    DEFF Research Database (Denmark)

    Hoang, Tran Phuong; Nguyen, Hai Truong; Hansen, Poul Erik

    2016-01-01

    [CholineCl][ZnCl2]3, a deep eutectic solvent between choline chloride and ZnCl2, has been used as a dual function catalyst and green solvent for the Friedel–Crafts acylation of aromatic compounds instead of using the moisture-sensitive Lewis acids and volatile organic solvents. The reactions...... are performed with high yields under microwave irradiation with short reaction times for the synthesis of ketones. Interestingly, indole derivatives are regioselectively acylated in the 3-position under mild conditions with high yields without NH protection. Three new ketone products are synthesized. [Choline......Cl][ZnCl2]3 is easily synthesized from choline chloride and zinc chloride at a low cost, with easy purification and environmentally benign compounds. [CholineCl][ZnCl2]3 can be reused up to five times without loss of catalytic activity, making it ideal in industrial processes....

  16. Genetic Algorithm-Based Optimization for Surface Roughness in Cylindrically Grinding Process Using Helically Grooved Wheels

    Science.gov (United States)

    Çaydaş, Ulaş; Çelik, Mahmut

    The present work is focused on the optimization of process parameters in cylindrical surface grinding of AISI 1050 steel with grooved wheels. Response surface methodology (RSM) and genetic algorithm (GA) techniques were merged to optimize the input variable parameters of grinding. The revolution speed of workpiece, depth of cut and number of grooves on the wheel were changed to explore their experimental effects on the surface roughness of machined bars. The mathematical models were established between the input parameters and response by using RSM. Then, the developed RSM model was used as objective functions on GA to optimize the process parameters.

  17. The development of an open architecture control system for CBN high speed grinding

    OpenAIRE

    Silva, E. Jannone da; Biffi, M.; Oliveira, J. F. G. de

    2004-01-01

    The aim of this project is the development of an open architecture controlling (OAC) system to be applied in the high speed grinding process using CBN tools. Besides other features, the system will allow a new monitoring and controlling strategy, by the adoption of open architecture CNC combined with multi-sensors, a PC and third-party software. The OAC system will be implemented in a high speed CBN grinding machine, which is being developed in a partnership between the University of São Paul...

  18. Deep Learning from Crowds

    DEFF Research Database (Denmark)

    Rodrigues, Filipe; Pereira, Francisco Camara

    Over the last few years, deep learning has revolutionized the field of machine learning by dramatically improving the stateof-the-art in various domains. However, as the size of supervised artificial neural networks grows, typically so does the need for larger labeled datasets. Recently...... networks from crowds. We begin by describing an EM algorithm for jointly learning the parameters of the network and the reliabilities of the annotators. Then, a novel general-purpose crowd layer is proposed, which allows us to train deep neural networks end-to-end, directly from the noisy labels......, crowdsourcing has established itself as an efficient and cost-effective solution for labeling large sets of data in a scalable manner, but it often requires aggregating labels from multiple noisy contributors with different levels of expertise. In this paper, we address the problem of learning deep neural...

  19. Awareness of tooth grinding and clenching from adolescence to young adulthood: a nine-year follow-up

    NARCIS (Netherlands)

    Strausz, T.; Ahlberg, J.; Lobbezoo, F.; Restrepo, C.; Hublin, C.; Ahlberg, K.; Könönen, M.

    2010-01-01

    How bruxism develops from adolescence to early adulthood remains unclear. A previous database was revisited to evaluate the natural course of self-reported tooth grinding and clenching among young Finns aged 14-23 using four assessments. Overall, the self-reported frequencies of both grinding and

  20. Off-flavor related volatiles in soymilk as affected by soybean variety, grinding, and heat-processing methods.

    Science.gov (United States)

    Zhang, Yan; Guo, Shuntang; Liu, Zhisheng; Chang, Sam K C

    2012-08-01

    Off-flavor of soymilk is a barrier to the acceptance of consumers. The objectionable soy odor can be reduced through inhibition of their formation or through removal after being formed. In this study, soymilk was prepared by three grinding methods (ambient, cold, and hot grinding) from two varieties (yellow Prosoy and a black soybean) before undergoing three heating processes: stove cooking, one-phase UHT (ultrahigh temperature), and two-phase UHT process using a Microthermics direct injection processor, which was equipped with a vacuuming step to remove injected water and volatiles. Eight typical soy odor compounds, generated from lipid oxidation, were extracted by a solid-phase microextraction method and analyzed by gas chromatography. The results showed that hot grinding and cold grinding significantly reduced off-flavor as compared with ambient grinding, and hot grinding achieved the best result. The UHT methods, especially the two-phase UHT method, were effective to reduce soy odor. Different odor compounds showed distinct concentration patterns because of different formation mechanisms. The two varieties behaved differently in odor formation during the soymilk-making process. Most odor compounds could be reduced to below the detection limit through a combination of hot grinding and two-phase UHT processing. However, hot grinding gave lower solid and protein recoveries in soymilk.

  1. Investigation of finely dispersed grind of magnetically hard SmCo5 and Nd2Fe14B alloys

    International Nuclear Information System (INIS)

    Balalaev, Yu.N.; Kosobudskij, I.D.

    2000-01-01

    Possibility of preparation of finely dispersed powders of SmCo 5 and Nd 2 Fe 14 B allays investigated and comparison of different types of grinding processes is conducted. Results of comparison of the processes in vibrational mills and disintegrators permit to conclude that density and structure of grindable materials effect on the rate and quality of grinding of magnetically hard alloys [ru

  2. Effect of simulated chairside grinding procedures using commercially available abrasive agents on the surface properties of zirconia

    Directory of Open Access Journals (Sweden)

    Ramandeep Sandhu

    2017-01-01

    Clinical Significance: Carbide burs along with copious water irrigation when used to grind zirconia intra-orally produces has a polishing effect, minimal change in hardness & no phase transformation. The present study advocates the use of carbides for chair-side grinding of zirconia.

  3. Effect of grinding conditions on the fatigue life of titanium 5Al-2.5Sn alloy

    Science.gov (United States)

    Rangaswamy, P.; Terutung, H.; Jeelani, S.

    1991-01-01

    An investigation into the effect of grinding conditions on the fatigue life of titanium 5Al-2.5Sn is presented. Damage to surface integrity and changes in the residual stresses distribution are studied to assess changes in fatigue life. A surface grinding machine, operating at speeds ranging from 2000 to 6000 fpm and using SiC wheels of grit sizes 60 and 120, was used to grind flat subsize specimens of 0.1-in. thickness. After grinding, the specimens were fatigued at a chosen stress and compared with the unadulterated material. A standard profilometer, a microhardness tester, and a scanning electron microscope were utilized to examine surface characteristics and measure roughness and hardness. Increased grinding speed in both wet and dry applications tended to decrease the fatigue life of the specimens. Fatigue life increased markedly at 2000 fpm under wet conditions, but then decreased at higher speeds. Grit size had no effect on the fatigue life.

  4. Clad vent set cup closure-weld-zone grinding evaluation

    International Nuclear Information System (INIS)

    Ulrich, G.B.; Woods, A.T.; Ohriner, E.K.

    1996-04-01

    Clad vent set (CVS) cups were ground in the closure-weld zone to reduce the wall-thickness variation created by the cup deep-drawing process. A significantly more uniform wall thickness would be beneficial for the CVS closure-weld operation. The goal was to reduce the average within-cup wall-thickness variation (defined as the range of wall thicknesses in the closure-weld zone) approximately 50% from the Cassini production value of 42 microm. This goal was shown to be achievable but, unfortunately, not with the existing blank and formed cup thicknesses

  5. Deep Energy Retrofit

    DEFF Research Database (Denmark)

    Zhivov, Alexander; Lohse, Rüdiger; Rose, Jørgen

    Deep Energy Retrofit – A Guide to Achieving Significant Energy User Reduction with Major Renovation Projects contains recommendations for characteristics of some of core technologies and measures that are based on studies conducted by national teams associated with the International Energy Agency...... Energy Conservation in Buildings and Communities Program (IEA-EBC) Annex 61 (Lohse et al. 2016, Case, et al. 2016, Rose et al. 2016, Yao, et al. 2016, Dake 2014, Stankevica et al. 2016, Kiatreungwattana 2014). Results of these studies provided a base for setting minimum requirements to the building...... envelope-related technologies to make Deep Energy Retrofit feasible and, in many situations, cost effective. Use of energy efficiency measures (EEMs) in addition to core technologies bundle and high-efficiency appliances will foster further energy use reduction. This Guide also provides best practice...

  6. Theoretical and experimental fundamentals of designing promising technological equipment to improve efficiency and environmental safety of highly viscous oil recovery from deep oil reservoirs

    Science.gov (United States)

    Moiseyev, V. A.; Nazarov, V. P.; Zhuravlev, V. Y.; Zhuykov, D. A.; Kubrikov, M. V.; Klokotov, Y. N.

    2016-12-01

    The development of new technological equipment for the implementation of highly effective methods of recovering highly viscous oil from deep reservoirs is an important scientific and technical challenge. Thermal recovery methods are promising approaches to solving the problem. It is necessary to carry out theoretical and experimental research aimed at developing oil-well tubing (OWT) with composite heatinsulating coatings on the basis of basalt and glass fibers. We used the method of finite element analysis in Nastran software, which implements complex scientific and engineering calculations, including the calculation of the stress-strain state of mechanical systems, the solution of problems of heat transfer, the study of nonlinear static, the dynamic transient analysis of frequency characteristics, etc. As a result, we obtained a mathematical model of thermal conductivity which describes the steady-state temperature and changes in the fibrous highly porous material with the heat loss by Stefan-Boltzmann's radiation. It has been performed for the first time using the method of computer modeling in Nastran software environments. The results give grounds for further implementation of the real design of the OWT when implementing thermal methods for increasing the rates of oil production and mitigating environmental impacts.

  7. Improving iodine homogeneity in NIST SRM 1548a Typical Diet by cryogenic grinding

    Czech Academy of Sciences Publication Activity Database

    Kučera, Jan; Kameník, Jan

    2015-01-01

    Roč. 20, č. 3 (2015), s. 189-194 ISSN 0949-1775 R&D Projects: GA ČR(CZ) GBP108/12/G108; GA MŠk LM2011019 Institutional support: RVO:61389005 Keywords : Iodine * reference material * NIST SRM 1548a * cryogenic grinding * homogeneity Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 1.010, year: 2015

  8. The effects of three different grinding methods in DNA extraction of ...

    African Journals Online (AJOL)

    uwerhiavwe

    2013-04-17

    Apr 17, 2013 ... The effects of three different grinding methods in DNA extraction of cowpea .... 100 mg of the leaf tissues were weighed in an electronic balance. CTAB method .... The primers were synthesized by Life Technologies (AB & Invitrogen). .... This work was supported by 'Shuang-Zhi Plan' of Sichuan. Agricultural ...

  9. Robustness of a cross contamination model describing transfer of pathogens during grinding of meat

    DEFF Research Database (Denmark)

    Møller, Cleide Oliveira de Almeida; Sant’Ana, A. S.; Hansen, Solvej Katrine Holm

    2016-01-01

    This study aimed to evaluate a cross contamination model for its capability of describing transfer of Salmonella spp. and L. monocytogenes during grinding of varying sizes and numbers of pieces of meats in two grinder systems. Data from 19 trials were collected. Three evaluation approaches were...

  10. Involvement of phenoloxidase in browning during grinding of Tenebrio molitor larvae

    NARCIS (Netherlands)

    Janssen, Renske H.; Lakemond, Catriona M.M.; Fogliano, Vincenzo; Renzone, Giovanni; Scaloni, Andrea; Vincken, Jean-Paul

    2017-01-01

    Insects are investigated as alternative protein source to meet the increasing demand for proteins in the future. Enzymatic browning occurring during grinding of insect and subsequent extraction of proteins can influence the proteins’ properties, but it is unclear which enzymes are responsible for

  11. Determining the optimum process parameter for grinding operations using robust process

    Energy Technology Data Exchange (ETDEWEB)

    Neseli, Suley Man; Asilturk, Ilhan; Celik, Levent [Univ. of Selcuk, Konya (Turkmenistan)

    2012-11-15

    We applied combined response surface methodology (RSM) and Taguchi methodology (TM) to determine optimum parameters for minimum surface roughness (Ra) and vibration (Vb) in external cylindrical grinding. First, an experiment was conducted in a CNC cylindrical grinding machine. The TM using L{sup 27} orthogonal array was applied to the design of the experiment. The three input parameters were workpiece revolution, feed rate and depth of cut; the outputs were vibrations and surface roughness. Second, to minimize wheel vibration and surface roughness, two optimized models were developed using computer aided single objective optimization. The experimental and statistical results revealed that the most significant grinding parameter for surface roughness and vibration is workpiece revolution followed by the depth of cut. The predicted values and measured values were fairly close, which indicates 2 ( 94.99 R{sup 2Ra}=and 2 92.73) R{sup 2Vb}=that the developed models can be effectively used to predict surface roughness and vibration in the grinding. The established model for determination of optimal operating conditions shows that a hybrid approach can lead to success of a robust process.

  12. Single Side Electrolytic In-Process Dressing (ELID) Grinding with Lapping Kinematics of Silicon Carbide

    Science.gov (United States)

    Khoshaim, Ahmed Bakr

    The demand for Silicon Carbide ceramics (SiC) has increased significantly in the last decade due to its reliable physical and chemical properties. The silicon carbide is widely used for aerospace segments in addition to many uses in the industry. Sometimes, a single side grinding is preferable than conventional grinding, for it has the ability to produce flat ceramics. However, the manufacturing cost is still high because of the high tool wear and long machining time. Part of the solution is to use electrolytic in process dressing (ELID) to reduce the processing time. The study on ELID single side grinding of ceramics has never been attempted before. The study involves four variables with three levels each. One of the variables, which is the eccentricity, is being investigated for the first time on ceramics. A full factorial design, for both the surface roughness and material removal rate, guides to calculate mathematical models that can predict future results. Three grinding wheel mesh sizes are used. An investigation of the influence of different grain size on the results can then be evaluated. The kinematics of the process was studied based on eccentricity in order to optimize the pattern of the diamond grains. The experiment is performed with the assist of the proposed specialized ELID fluid, TRIM C270E.

  13. Effect of ultrafine grinding on physicochemical and antioxidant properties of dietary fiber from wine grape pomace.

    Science.gov (United States)

    Zhu, Feng-Mei; Du, Bin; Li, Jun

    2014-01-01

    Wine grape pomace dietary fiber powders were prepared by superfine grinding, whose effects were investigated on the composition, functional and antioxidant properties of the wine grape pomace dietary fiber products. The results showed that superfine grinding could effectively pulverize the fiber particles to submicron scale. As particle size decrease, the functional properties (water-holding capacity, water-retention capacity, swelling capacity, oil-binding capacity, and nitrite ion absorption capacity) of wine grape pomace dietary fiber were significantly (p fiber components from insoluble to soluble fractions was observed. The antioxidant activities of wine grape pomace and dietary fiber before and after grinding were in terms of DPPH radical scavenging activity, ABTS diammonium salt radical scavenging activity, ferric reducing antioxidant power, and total phenolic content. Compared with dietary fiber before and after grinding, micronized insoluble dietary fiber showed increased ABTS radical scavenging activity, ferric reducing antioxidant power, and total phenolic content yet decreased DPPH radical scavenging activity. Positive correlations were detected between ABTS radical scavenging activity, ferric reducing antioxidant power, and total phenolic content.

  14. Determining the optimum process parameter for grinding operations using robust process

    International Nuclear Information System (INIS)

    Neseli, Suley Man; Asilturk, Ilhan; Celik, Levent

    2012-01-01

    We applied combined response surface methodology (RSM) and Taguchi methodology (TM) to determine optimum parameters for minimum surface roughness (Ra) and vibration (Vb) in external cylindrical grinding. First, an experiment was conducted in a CNC cylindrical grinding machine. The TM using L 27 orthogonal array was applied to the design of the experiment. The three input parameters were workpiece revolution, feed rate and depth of cut; the outputs were vibrations and surface roughness. Second, to minimize wheel vibration and surface roughness, two optimized models were developed using computer aided single objective optimization. The experimental and statistical results revealed that the most significant grinding parameter for surface roughness and vibration is workpiece revolution followed by the depth of cut. The predicted values and measured values were fairly close, which indicates 2 ( 94.99 R 2Ra =and 2 92.73) R 2Vb =that the developed models can be effectively used to predict surface roughness and vibration in the grinding. The established model for determination of optimal operating conditions shows that a hybrid approach can lead to success of a robust process

  15. Effect of surface grinding on chloride induced SCC of 304L

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Nian, E-mail: nzh@du.se [Department of Material Science, Dalarna University, SE-79188 Falun (Sweden); KTH, SE-10044 Stockholm (Sweden); Pettersson, Rachel [KTH, SE-10044 Stockholm (Sweden); Jernkontoret, SE-11187 Stockholm (Sweden); Lin Peng, Ru [Department of Management and Engineering, Linköping University, SE-58183 Linköping (Sweden); Schönning, Mikael [Corrosion Department, Avesta Research Centre – Outokumpu Stainless AB, SE-774 22 Avesta (Sweden)

    2016-03-21

    The effect of surface grinding on the stress corrosion cracking (SCC) behavior of 304L austenitic stainless steel in boiling magnesium chloride has been investigated. SCC tests were conducted both without external loading and with varied levels of four-point bend loading for as-delivered material and for specimens which had been ground parallel or perpendicular to the loading direction. Residual stresses due to the grinding operation were measured using the X-ray diffraction technique. In addition, surface stress measurements under applied load were performed before exposure to evaluate the deviation between actual applied loading and calculated values according to ASTM G39. Micro-cracks initiated by a high level of tensile residual stress in the surface layer were observed for all the ground specimens but not those in the as-delivered condition. Grinding along the loading direction increased the susceptibility to chloride induced SCC; while grinding perpendicular to the loading direction improved SCC resistance. Surface tensile residual stresses were largely relieved after the initiation of cracks.

  16. Fatigue limit of polycrystalline zirconium oxide ceramics: effect of grinding and low-temperature aging

    NARCIS (Netherlands)

    Pereira, G.K.R.; Silvestri, T.; Amaral, M.; Rippe, M.P.; Kleverlaan, C.J.; Valandro, L.F.

    2016-01-01

    The following study aimed to evaluate the effect of grinding and low-temperature aging on the fatigue limit of Y-TZP ceramics for frameworks and monolithic restorations. Disc specimens from each ceramic material, Lava Frame (3M ESPE) and Zirlux FC (Ivoclar Vivadent) were manufactured according to

  17. PENGARUH GUGUS p-METOKSI PADA REAKSI KONDENSASI CLAYSEN-SCHMIDT MENGGUNAKAN METODA GRINDING

    Directory of Open Access Journals (Sweden)

    Karim Theresih

    2016-10-01

      This research aims to synthesize the compound dibenzalaceton, 4-methoksikalkon and dianisalaceton through Claysen Schmidt condensation reaction with grinding method and to determine the effect of p-methoxy groups on the reaction. Dibenzalaceton compound was synthesized from benzaldehyde, acetone, and NaOH. Synthesis of compound 4-metoksikhalkon was done using 4-methoxybenzaldehyde, acetophenone, and NaOH. Dianisalceton compound was synthesized through Claysen-schmidt reaction between acetone, anisaldehide, and the catalysts NaOH. This synthesis were performed through solvent-free grinding method. Catalyst base material and simultaneously crushed in mortar for 15 minutes to form a paste. The pasta is dried and recrystallized. The resulted compounds were characterized by TLC, FTIR and GC-MS. Based on the results of the analysis of FTIR and GC-MS showed that dibenzalaceton, 4-methoksikhalkon and dianisalaceton can be synthesized and have succession yield 59.93%, 86.21% and 70.39% . There is the influence of p-methoxy groups in a condensation reaction Claysen-Schmidt on the synthesis of compounds dibenzalaceton, 4-methoksikhalkon and dianizalaceton use grinding method.   Keywords: dibenzalaceton, 4-methoksikhalkon, dianizalaceton, grinding method

  18. Optimization of Process Variables for Grinding of Ibuprofen using Response Surface Methodology

    Energy Technology Data Exchange (ETDEWEB)

    Sim, Chol-Ho [Sangji University, Wonju (Korea, Republic of)

    2013-12-15

    Ibuprofen, non-steroidal anti-inflammatory drugs; NSAIDs, is a highly crystalline substance with the pharmaceutical properties of poor solubility and low bioavailability. The size reduction of ibuprofen is needed to improve the solubility. The objective of this study is to optimize the grinding condition of ibuprofen. Grinding of ibuprofen was carried out using a planetary mill. Grinding parameters were optimized using Box-Behnken experimental design method. The physical characteristics of ground ibuprofen were investigated for the particle size by particle size analyzer, for the crystal size by X-ray diffraction (XRD), and for the tensile strength by tensile/compression tester. The optimum conditions for the milling of ibuprofen were 290 rpm of the revolution number of mill, 24.6 g of the weight of sample, and 10minutes of grinding time. The measured value of the particle size of ground ibuprofen at these optimum conditions was 13.5 µm. The results showed that the crystal size of ibuprofen was reduced by the planetary milling process. In case the relative density of the tablets formulated of ground ibuprofen was range of 0.85-0.90, the tensile strength of them was range of 12-14 Kg{sub f}/cm{sup 2}.

  19. The Manufacture of the Grinding Wheels Based on the Ca–K Geopolymer Matrix

    Czech Academy of Sciences Publication Activity Database

    Perná, Ivana; Hanzlíček, Tomáš; Boura, P.; Lučaník, A.

    2016-01-01

    Roč. 31, č. 5 (2016), s. 667-672 ISSN 1042-6914 Institutional support: RVO:67985891 Keywords : geopolymer * grinding * wheel * low-temperature * industrial * manufacturing * technology Subject RIV: DM - Solid Waste and Recycling Impact factor: 2.274, year: 2016

  20. Mechanical properties of silicon in subsurface damage layer from nano-grinding studied by atomistic simulation

    Science.gov (United States)

    Zhang, Zhiwei; Chen, Pei; Qin, Fei; An, Tong; Yu, Huiping

    2018-05-01

    Ultra-thin silicon wafer is highly demanded by semi-conductor industry. During wafer thinning process, the grinding technology will inevitably induce damage to the surface and subsurface of silicon wafer. To understand the mechanism of subsurface damage (SSD) layer formation and mechanical properties of SSD layer, atomistic simulation is the effective tool to perform the study, since the SSD layer is in the scale of nanometer and hardly to be separated from underneath undamaged silicon. This paper is devoted to understand the formation of SSD layer, and the difference between mechanical properties of damaged silicon in SSD layer and ideal silicon. With the atomistic model, the nano-grinding process could be performed between a silicon workpiece and diamond tool under different grinding speed. To reach a thinnest SSD layer, nano-grinding speed will be optimized in the range of 50-400 m/s. Mechanical properties of six damaged silicon workpieces with different depths of cut will be studied. The SSD layer from each workpiece will be isolated, and a quasi-static tensile test is simulated to perform on the isolated SSD layer. The obtained stress-strain curve is an illustration of overall mechanical properties of SSD layer. By comparing the stress-strain curves of damaged silicon and ideal silicon, a degradation of Young's modulus, ultimate tensile strength (UTS), and strain at fracture is observed.

  1. Smooth brome (Bromus inermis Leyss) response to concrete grinding residue application

    Science.gov (United States)

    Concrete grinding residue (CGR) is a slurry byproduct created by concrete pavement maintenance operations. The application of CGR to roadside soils is not consistently regulated by state agencies across the United States. Much of this variability in regulation may be due to the lack of science-base...

  2. Investigation on the potential of waste cooking oil as a grinding aid in Portland cement.

    Science.gov (United States)

    Li, Haoxin; Zhao, Jianfeng; Huang, Yuyan; Jiang, Zhengwu; Yang, Xiaojie; Yang, Zhenghong; Chen, Qing

    2016-12-15

    Although there are several methods for managing waste cooking oil (WCO), a significant result has not been achieved in China. A new method is required for safe WCO management that minimizes the environmental threat. In this context, this work was developed in which cement clinker and gypsum were interground with various WCOs, and their properties, such as grindability, water-cement ratio required to achieve a normal consistency, setting times, compressive strength, contents of calcium hydroxide and ettringite in the hardened paste, microstructure and economic and environmental considerations, were addressed in detail. The results show that, overall, WCO favorably improves cement grinding. WCO prolonged the cement setting times and resulted in longer setting times. Additionally, more remarkable effects were found in cements in which WCO contained more unsaturated fatty acid. WCOs increased the cement strength. However, this enhancement was rated with respect to the WCO contents and components. WCOs decreased the CH and AFt contents in the cement hardened paste. Even the AFt content at later ages was reduced when WCO was used. WCO also densify microstructure of the hardened cement paste. It is economically and environmentally feasible to use WCOs as grinding aids in the cement grinding process. These results contribute to the application of WCOs as grinding aids and to the safe management of WCO. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. Natural mediotrusive contact: does it affect the masticatory and neck EMG activity during tooth grinding?

    Science.gov (United States)

    Fuentes, Aler D; Martin, Conchita; Bull, Ricardo; Santander, Hugo; Gutiérrez, Mario F; Miralles, Rodolfo

    2016-07-01

    There is scarce knowledge regarding the influence of a natural mediotrusive contact on mandibular and cervical muscular activity. The purpose of this study was to analyze the EMG activity of the anterior temporalis (AT) and sternocleidomastoid (SCM) muscles during awake grinding in healthy subjects with or without a natural mediotrusive occlusal contact. Fifteen subjects with natural mediotrusive occlusal contact (Group 1) and 15 subjects without natural mediotrusive occlusal contact (Group 2) participated. Bilateral surface EMG activity of AT and SCM muscles was recorded during unilateral eccentric or concentric tooth grinding tasks. EMG activity was normalized against the activity recorded during maximal voluntary clenching in intercuspal position (IP) for AT muscles and during maximal intentional isometric head-neck rotation to each side, for SCM muscles. EMG activity of AT and SCM muscles showed no statistical difference between groups. EMG activity of AT muscle was higher in the working side (WS) than in the non-WS (NWS) in Group 1 during concentric grinding (0.492 vs 0.331, p = 0.047), whereas no difference was observed in Group 2. EMG activity of SCM was similar between working and NWSs in both groups and tasks. Asymmetry indexes (AIs) were not significantly different between groups. These findings in healthy subjects support the assumption that during awake tooth grinding, central nerve control predominates over peripheral inputs, and reinforce the idea of a functional link between the motor-neuron pools that control jaw and neck muscles.

  4. SCC of 2304 Duplex Stainless Steel-Microstructure, Residual Stress and Surface Grinding Effects.

    Science.gov (United States)

    Zhou, Nian; Peng, Ru Lin; Schönning, Mikael; Pettersson, Rachel

    2017-02-23

    The influence of surface grinding and microstructure on chloride induced stress corrosion cracking (SCC) behavior of 2304 duplex stainless steel has been investigated. Grinding operations were performed both parallel and perpendicular to the rolling direction of the material. SCC tests were conducted in boiling magnesium chloride according to ASTM G36; specimens were exposed both without external loading and with varied levels of four-point bend loading. Residual stresses were measured on selected specimens before and after exposure using the X-ray diffraction technique. In addition, in-situ surface stress measurements subjected to four-point bend loading were performed to evaluate the deviation between the actual applied loading and the calculated values according to ASTM G39. Micro-cracks, initiated by grinding induced surface tensile residual stresses, were observed for all the ground specimens but not on the as-delivered surfaces. Loading transverse to the rolling direction of the material increased the susceptibility to chloride induced SCC. Grinding induced tensile residual stresses and micro-notches in the as-ground surface topography were also detrimental.

  5. Grinding and cooking dry-mill germ to optimize aqueous enzymatic oil extraction

    Science.gov (United States)

    The many recent dry grind plants that convert corn to ethanol are potential sources of substantial amounts of corn oil. This report describes an aqueous enzymatic extraction (AEE) method to separate oil from dry-mill corn germ (DMG). The method is an extension of AEE previously developed for wet...

  6. SCC of 2304 Duplex Stainless Steel—Microstructure, Residual Stress and Surface Grinding Effects

    Directory of Open Access Journals (Sweden)

    Nian Zhou

    2017-02-01

    Full Text Available The influence of surface grinding and microstructure on chloride induced stress corrosion cracking (SCC behavior of 2304 duplex stainless steel has been investigated. Grinding operations were performed both parallel and perpendicular to the rolling direction of the material. SCC tests were conducted in boiling magnesium chloride according to ASTM G36; specimens were exposed both without external loading and with varied levels of four-point bend loading. Residual stresses were measured on selected specimens before and after exposure using the X-ray diffraction technique. In addition, in-situ surface stress measurements subjected to four-point bend loading were performed to evaluate the deviation between the actual applied loading and the calculated values according to ASTM G39. Micro-cracks, initiated by grinding induced surface tensile residual stresses, were observed for all the ground specimens but not on the as-delivered surfaces. Loading transverse to the rolling direction of the material increased the susceptibility to chloride induced SCC. Grinding induced tensile residual stresses and micro-notches in the as-ground surface topography were also detrimental.

  7. Effect of heat treatment on wear resistance of a grinding plate ...

    African Journals Online (AJOL)

    Some of the specimens were quenched in water and palm oil, while some of the quenched specimens were tempered at 200°C. The results obtained were corroborated with the microstructure of the specimens examined under an optical microscope. The hardness values of the grinding plate specimens quenched in ...

  8. Optimization of Process Variables for Grinding of Ibuprofen using Response Surface Methodology

    International Nuclear Information System (INIS)

    Sim, Chol-Ho

    2013-01-01

    Ibuprofen, non-steroidal anti-inflammatory drugs; NSAIDs, is a highly crystalline substance with the pharmaceutical properties of poor solubility and low bioavailability. The size reduction of ibuprofen is needed to improve the solubility. The objective of this study is to optimize the grinding condition of ibuprofen. Grinding of ibuprofen was carried out using a planetary mill. Grinding parameters were optimized using Box-Behnken experimental design method. The physical characteristics of ground ibuprofen were investigated for the particle size by particle size analyzer, for the crystal size by X-ray diffraction (XRD), and for the tensile strength by tensile/compression tester. The optimum conditions for the milling of ibuprofen were 290 rpm of the revolution number of mill, 24.6 g of the weight of sample, and 10minutes of grinding time. The measured value of the particle size of ground ibuprofen at these optimum conditions was 13.5 µm. The results showed that the crystal size of ibuprofen was reduced by the planetary milling process. In case the relative density of the tablets formulated of ground ibuprofen was range of 0.85-0.90, the tensile strength of them was range of 12-14 Kg f /cm 2

  9. Effect of surface grinding on chloride induced SCC of 304L

    International Nuclear Information System (INIS)

    Zhou, Nian; Pettersson, Rachel; Lin Peng, Ru; Schönning, Mikael

    2016-01-01

    The effect of surface grinding on the stress corrosion cracking (SCC) behavior of 304L austenitic stainless steel in boiling magnesium chloride has been investigated. SCC tests were conducted both without external loading and with varied levels of four-point bend loading for as-delivered material and for specimens which had been ground parallel or perpendicular to the loading direction. Residual stresses due to the grinding operation were measured using the X-ray diffraction technique. In addition, surface stress measurements under applied load were performed before exposure to evaluate the deviation between actual applied loading and calculated values according to ASTM G39. Micro-cracks initiated by a high level of tensile residual stress in the surface layer were observed for all the ground specimens but not those in the as-delivered condition. Grinding along the loading direction increased the susceptibility to chloride induced SCC; while grinding perpendicular to the loading direction improved SCC resistance. Surface tensile residual stresses were largely relieved after the initiation of cracks.

  10. SCC of 2304 Duplex Stainless Steel—Microstructure, Residual Stress and Surface Grinding Effects

    Science.gov (United States)

    Zhou, Nian; Peng, Ru Lin; Schönning, Mikael; Pettersson, Rachel

    2017-01-01

    The influence of surface grinding and microstructure on chloride induced stress corrosion cracking (SCC) behavior of 2304 duplex stainless steel has been investigated. Grinding operations were performed both parallel and perpendicular to the rolling direction of the material. SCC tests were conducted in boiling magnesium chloride according to ASTM G36; specimens were exposed both without external loading and with varied levels of four-point bend loading. Residual stresses were measured on selected specimens before and after exposure using the X-ray diffraction technique. In addition, in-situ surface stress measurements subjected to four-point bend loading were performed to evaluate the deviation between the actual applied loading and the calculated values according to ASTM G39. Micro-cracks, initiated by grinding induced surface tensile residual stresses, were observed for all the ground specimens but not on the as-delivered surfaces. Loading transverse to the rolling direction of the material increased the susceptibility to chloride induced SCC. Grinding induced tensile residual stresses and micro-notches in the as-ground surface topography were also detrimental. PMID:28772582

  11. Mechanical properties of silicon in subsurface damage layer from nano-grinding studied by atomistic simulation

    Directory of Open Access Journals (Sweden)

    Zhiwei Zhang

    2018-05-01

    Full Text Available Ultra-thin silicon wafer is highly demanded by semi-conductor industry. During wafer thinning process, the grinding technology will inevitably induce damage to the surface and subsurface of silicon wafer. To understand the mechanism of subsurface damage (SSD layer formation and mechanical properties of SSD layer, atomistic simulation is the effective tool to perform the study, since the SSD layer is in the scale of nanometer and hardly to be separated from underneath undamaged silicon. This paper is devoted to understand the formation of SSD layer, and the difference between mechanical properties of damaged silicon in SSD layer and ideal silicon. With the atomistic model, the nano-grinding process could be performed between a silicon workpiece and diamond tool under different grinding speed. To reach a thinnest SSD layer, nano-grinding speed will be optimized in the range of 50-400 m/s. Mechanical properties of six damaged silicon workpieces with different depths of cut will be studied. The SSD layer from each workpiece will be isolated, and a quasi-static tensile test is simulated to perform on the isolated SSD layer. The obtained stress-strain curve is an illustration of overall mechanical properties of SSD layer. By comparing the stress-strain curves of damaged silicon and ideal silicon, a degradation of Young’s modulus, ultimate tensile strength (UTS, and strain at fracture is observed.

  12. Cocrystal Screening of Ibuprofen with Oxalic Acid and Citric Acid via Grinding Method

    Science.gov (United States)

    Othman, M. F.; Anuar, N.; Rahman, S. Ad; Taifuddin, N. A. Ahmad

    2018-05-01

    Ibuprofen is a Class II Biological Safety Class (BSC) drugs used for relief of arthritis, as an analgesic and possesses the effect of antiplatelet. The major problem involves in ibuprofen is it has a low solubility and high permeability thus causes an unsatisfactory therapeutic effect to humans. Thus, in this work, alteration of ibuprofen’s physicochemical properties is conducted by means of cocrystallization technique. Co-crystallizations of ibuprofen were prepared with selected coformers using dry grinding and liquid assisted grinding (LAG) techniques in different molar ratios while ethanol and propanol were used as a solvent. The new crystalline forms were identified and characterized by differential scanning calorimetry (DSC), powder X-ray diffraction (PXRD) and fourier transform infrared spectroscopy (FTIR). Analysis for Ibuprofen-Citric acid (IBP-CA) system, co-crystal was successfully formed in 1:2, 1:3, 2:1 and 3:1 molar ratios for neat grinding method although the co-crystal produced is unstable. Meanwhile, for Ibuprofen-Oxalic acid (IBP-OA) system, the co-crystal formation was identified only in 1:1, 1:2 and 1:3 molar ratios for the neat grinding method. LAG method shows that co-crystal formation was unsuccessful in both solvents for IBP-CA, while IBP-OA co-crystal was formed in the molar ratio 1:1, 2:1 and 3:1 in ethanol, and 2:1 and 3:1 in propanol.

  13. Modeling and evaluating of surface roughness prediction in micro-grinding on soda-lime glass considering tool characterization

    Science.gov (United States)

    Cheng, Jun; Gong, Yadong; Wang, Jinsheng

    2013-11-01

    The current research of micro-grinding mainly focuses on the optimal processing technology for different materials. However, the material removal mechanism in micro-grinding is the base of achieving high quality processing surface. Therefore, a novel method for predicting surface roughness in micro-grinding of hard brittle materials considering micro-grinding tool grains protrusion topography is proposed in this paper. The differences of material removal mechanism between convention grinding process and micro-grinding process are analyzed. Topography characterization has been done on micro-grinding tools which are fabricated by electroplating. Models of grain density generation and grain interval are built, and new predicting model of micro-grinding surface roughness is developed. In order to verify the precision and application effect of the surface roughness prediction model proposed, a micro-grinding orthogonally experiment on soda-lime glass is designed and conducted. A series of micro-machining surfaces which are 78 nm to 0.98 μm roughness of brittle material is achieved. It is found that experimental roughness results and the predicting roughness data have an evident coincidence, and the component variable of describing the size effects in predicting model is calculated to be 1.5×107 by reverse method based on the experimental results. The proposed model builds a set of distribution to consider grains distribution densities in different protrusion heights. Finally, the characterization of micro-grinding tools which are used in the experiment has been done based on the distribution set. It is concluded that there is a significant coincidence between surface prediction data from the proposed model and measurements from experiment results. Therefore, the effectiveness of the model is demonstrated. This paper proposes a novel method for predicting surface roughness in micro-grinding of hard brittle materials considering micro-grinding tool grains protrusion

  14. Dependence of rates of breakage on fines content in wet ball mill grinding

    Science.gov (United States)

    Bhattacharyya, Anirban

    The following research fundamentally deals with the cause and implications of nonlinearities in breakage rates of materials in wet grinding systems. The innate dependence of such nonlinearities on fines content and the milling environment during wet grinding operations is also tested and observed. Preferential breakage of coarser size fractions as compared to the finer size fractions in a particle population were observed and discussed. The classification action of the pulp was deemed to be the probable cause for such a peculiarity. Ores with varying degrees of hardness and brittleness were used for wet grinding experiments, primarily to test the variations in specific breakage rates as a function of varying hardness. For this research, limestone, quartzite, and gold ore were used. The degree of hardness is of the order of: limestone, quartzite, gold ore. Selection and breakage function parameters were determined in the course of this research. Functional forms of these expressions were used to compare experimentally derived parameter estimates. Force-fitting of parameters was not done in order to examine the realtime behavior of particle populations in wet grinding systems. Breakage functions were established as being invariant with respect to such operating variables like ball load, mill speed, particle load, and particle size distribution of the mill. It was also determined that specific selection functions were inherently dependent on the particle size distribution in wet grinding systems. Also, they were consistent with inputs of specific energy, according to grind time. Nonlinearity trends were observed for 1st order specific selection functions which illustrated variations in breakage rates with incremental inputs of grind time and specific energy. A mean particle size called the fulcrum was noted below which the nonlinearities in the breakage trends were observed. This magnitude of the fulcrum value varied with percent solids and slurry filling, indicating

  15. Biopharmaceutical characterization of praziquantel cocrystals and cyclodextrin complexes prepared by grinding.

    Science.gov (United States)

    Cugovčan, Martina; Jablan, Jasna; Lovrić, Jasmina; Cinčić, Dominik; Galić, Nives; Jug, Mario

    2017-04-15

    Mechanochemical activation using several different co-grinding additives was applied as a green chemistry approach to improve physiochemical and biopharmaceutical properties of praziquantel (PZQ). Liquid assisted grinding with an equimolar amount of citric acid (CA), malic acid (MA), salicylic acid (SA) and tartaric acid (TA) gained in cocrystal formation, which all showed pH-dependent solubility and dissolution rate. However, the most soluble cocrystal of PZQ with MA was chemically unstable, as seen during the stability testing. Equimolar cyclodextrin complexes prepared by neat grinding with amorphous hydroxypropyl-β-cyclodextrin (HPβCD) and randomly methylated β-cyclodextrin (MEβCD) showed the highest improvement in drug solubility and the dissolution rate, but only PZQ/HPβCD product presented an acceptable chemical and photostability profile. A combined approach, by co-grinding the drug with both MA and HPβCD in equimolar ratio, also gave highly soluble amorphous product which again was chemical instable and therefore not suitable for the pharmaceutical use. Studies on Caco-2 monolayer confirmed the biocompatibility of PZQ/HPβCD complex and showed that complexation did not adversely affect the intrinsically high PZQ permeability (P app (PZQ)=(3.72±0.33)×10 -5 cms -1 and P app (PZQ/HPβCD)=(3.65±0.21)×10 -5 cms -1 ; p>0.05). All this confirmed that the co-grinding with the proper additive is as a promising strategy to improve biopharmaceutical properties of the drug. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Ibuprofen-Amino Acids Co-Crystal Screening Via Co-Grinding Methods

    Directory of Open Access Journals (Sweden)

    Othman Muhamad Fitri

    2016-01-01

    Full Text Available The importance of pharmaceutical co-crystals now has been recognized in order to improve the research and development in pharmaceutical industries. Low solubility of active pharmaceutical ingredient (API has led to the growth of new pharmaceutical co-crystals formation as it enhances the physicochemical properties of the API. In this works, preparation of new co-crystal formation between ibuprofen (IBP with selected amino acid compounds were performed by using dry grinding and liquid assisted grinding (LAG techniques. Ibuprofen (IBP was selected as the API meanwhile glycine (GLY, L-alanine (ALA and L-proline (PRO were selected as co-crystal former (CCF agents. The products of IBP-co-former from grinding experiments for the formation of co-crystals were characterized and verified using X-Ray Powder Diffraction (XRPD, Differential Scanning Calorimetry (DSC and Fourier Transform Infra-Red Spectroscopy (FTIR. The finding reveals that the IBP-PRO co-crystals have successfully formed. For IBP-PRO system, new crystalline peaks from XRPD were recorded at 2θ values of 4.374°, 5.436° and 10.944° from dry grinding technique and 4.41°, 5.436° and 10.962° for liquid assisted grinding (LAG technique. A new melting point of 257.49 °C was discovered for IBP-ALA indicates the possibility of co-crystals formation. On the other hand, the analysis for IBP-GLY shows that no co-crystals formed in the system.

  17. Influence of pin and hammer mill on grinding characteristics, thermal and antioxidant properties of coriander powder.

    Science.gov (United States)

    Barnwal, P; Singh, K K; Sharma, Alka; Choudhary, A K; Saxena, S N

    2015-12-01

    In present study, influence of grinding (hammer and pin mills) and moisture content (range: 6.4-13.6 % dry basis) on the quality traits of coriander powder were investigated. These include grinding parameters, colour parameters, specific heat, thermal conductivity, thermal diffusivity, glass transition temperature, essential oil, total phenolic content, total flavonoid content and DPPH scavenging (%) of coriander powder. For coriander seed, the geometric properties such as major, medium, minor dimensions, geometric mean diameter, arithmetic mean diameter, sphericity, surface area and volume of coriander seeds increased significantly with increasing moisture (6.4-13.6 % db). For coriander powder, the grinding parameters such as average particle size, volume surface mean diameter and volume mean diameter increased significantly with increasing moisture (6.4-13.6 % db). With the grinding method, the colour attributes of coriander powder such as L-value, a-value, b-value, hue angle and browning index varied significantly. It was observed that the specific heat followed second order polynomial relationship with temperature and moisture whereas thermal conductivity varied linearly with temperature and moisture content. The variation of glass transition temperature with moisture can be best represented in quadratic manner. Total flavonoid content (mg QE/g crude seed extract) and DPPH scavenging % activity of coriander powder is significantly affected by grinding methods. A lower value of specific heat was observed for hammer ground coriander powder as compared to pin mill ground coriander powder. The thermal conductivity of hammer mill ground coriander powder was higher as compared to pin mill ground coriander. It was observed that hammer mill yields more fine coriander powder in comparison to pin mill. The browning index was more in hammer mill ground coriander powder.

  18. Effects of Different Grinding Methods on Morphological, Textural Properties and Pasting Profiles of MR220 Rice Flour

    International Nuclear Information System (INIS)

    Noorlaila Ahmad; Asmeda Rajab; Norziah Mohd Hani

    2016-01-01

    Three different grinding techniques (dry, semi-wet, and wet) were employed in rice flour production. Investigation on the effects of the grinding techniques on starch damage percentage, particle size distribution, pasting profiles, morphological and textural properties of rice flours produced were evaluated. Wet grinding resulted in significantly (p<0.05) has lower percentage of damaged starch (3.24 %) than other grinding methods. Morphological studies (microscopy and particle size analysis) have reflected significant differences among rice flours granule shapes. The granules displaying different shapes of polygonal, round and angular forms, with some as an individual granule while others tend to attached together. Wet grinding technique also yielded flour that exhibit significantly (p<0.05) with higher gel hardness (16.62 g). Pasting profiles showed that pasting temperature for rice flour produce using these three grinding methods varied between 80.15 - 80.42 degree Celcius. Results revealed that the three grinding techniques clearly affected the physicochemical properties of rice flour. The results from this study play an important role in the selection criteria of rice flour with desirable pasting and textural properties for manufacturing rice-based product. (author)

  19. On-machine measurement of the grinding wheels' 3D surface topography using a laser displacement sensor

    Science.gov (United States)

    Pan, Yongcheng; Zhao, Qingliang; Guo, Bing

    2014-08-01

    A method of non-contact, on-machine measurement of three dimensional surface topography of grinding wheels' whole surface was developed in this paper, focusing on an electroplated coarse-grained diamond grinding wheel. The measuring system consists of a Keyence laser displacement sensor, a Keyence controller and a NI PCI-6132 data acquisition card. A resolution of 0.1μm in vertical direction and 8μm in horizontal direction could be achieved. After processing the data by LabVIEW and MATLAB, the 3D topography of the grinding wheel's whole surface could be reconstructed. When comparing the reconstructed 3D topography of the grinding wheel's marked area to its real topography captured by a high-depth-field optical digital microscope (HDF-ODM) and scanning electron microscope (SEM), they were very similar to each other, proving that this method is accurate and effective. By a subsequent data processing, the topography of every grain could be extracted and then the active grain number, the active grain volume and the active grain's bearing ration could be calculated. These three parameters could serve as the criterion to evaluate the grinding performance of coarse-grained diamond grinding wheels. Then the performance of the grinding wheel could be evaluated on-machine accurately and quantitatively.

  20. Deep Learning

    DEFF Research Database (Denmark)

    Jensen, Morten Bornø; Bahnsen, Chris Holmberg; Nasrollahi, Kamal

    2018-01-01

    I løbet af de sidste 10 år er kunstige neurale netværk gået fra at være en støvet, udstødt tekno-logi til at spille en hovedrolle i udviklingen af kunstig intelligens. Dette fænomen kaldes deep learning og er inspireret af hjernens opbygning.......I løbet af de sidste 10 år er kunstige neurale netværk gået fra at være en støvet, udstødt tekno-logi til at spille en hovedrolle i udviklingen af kunstig intelligens. Dette fænomen kaldes deep learning og er inspireret af hjernens opbygning....

  1. Evaluation of a cross contamination model describing transfer of salmonella spp. and listeria monocytogenes during grinding of pork and beef

    DEFF Research Database (Denmark)

    Møller, Cleide Oliveira de Almeida; Hansen, Tina Beck; Aabo, Søren

    2015-01-01

    Introduction: The cross contamination model (Møller et al. 2012) was evaluated to investigate its capability of describing transfer of Salmonella spp. and Listeria monocytogenes during grinding of pork and beef of varying sizes (50 – 324 g) and numbers of pieces to be ground (10 – 100), in two...... processing. QMRA risk estimates and TTP both revealed that risk attribution from grinding was mainly influenced by sharpness of grinder knife > specific grinder > grinding temperature whereas the specific pathogen was of minor importance....

  2. Liquid-assisted grinding and ion pairing regulates percentage conversion and diastereoselectivity of the Wittig reaction under mechanochemical conditions.

    Science.gov (United States)

    Denlinger, Kendra Leahy; Ortiz-Trankina, Lianna; Carr, Preston; Benson, Kingsley; Waddell, Daniel C; Mack, James

    2018-01-01

    Mechanochemistry is maturing as a discipline and continuing to grow, so it is important to continue understanding the rules governing the system. In a mechanochemical reaction, the reactants are added into a vessel along with one or more grinding balls and the vessel is shaken at high speeds to facilitate a chemical reaction. The dielectric constant of the solvent used in liquid-assisted grinding (LAG) and properly chosen counter-ion pairing increases the percentage conversion of stilbenes in a mechanochemical Wittig reaction. Utilizing stepwise addition/evaporation of ethanol in liquid-assisted grinding also allows for the tuning of the diastereoselectivity in the Wittig reaction.

  3. Effectiveness of dust control methods for crystalline silica and respirable suspended particulate matter exposure during manual concrete surface grinding.

    Science.gov (United States)

    Akbar-Khanzadeh, Farhang; Milz, Sheryl A; Wagner, Cynthia D; Bisesi, Michael S; Ames, April L; Khuder, Sadik; Susi, Pam; Akbar-Khanzadeh, Mahboubeh

    2010-12-01

    Concrete grinding exposes workers to unacceptable levels of crystalline silica dust, known to cause diseases such as silicosis and possibly lung cancer. This study examined the influence of major factors of exposure and effectiveness of existing dust control methods by simulating field concrete grinding in an enclosed workplace laboratory. Air was monitored during 201 concrete grinding sessions while using a variety of grinders, accessories, and existing dust control methods, including general ventilation (GV), local exhaust ventilation (LEV), and wet grinding. Task-specific geometric mean (GM) of respirable crystalline silica dust concentrations (mg/m³ for LEV:HEPA-, LEV:Shop-vac-, wet-, and uncontrolled-grinding, while GV was off/on, were 0.17/0.09, 0.57/0.13, 1.11/0.44, and 23.1/6.80, respectively. Silica dust concentrations (mg/m³ using 100-125 mm (4-5 inch) and 180 mm (7 inch) grinding cups were 0.53/0.22 and 2.43/0.56, respectively. GM concentrations of silica dust were significantly lower for (1) GV on (66.0%) vs. off, and (2) LEV:HEPA- (99.0%), LEV:Shop-vac- (98.1%) or wet- (94.4%) vs. uncontrolled-grinding. Task-specific GM of respirable suspended particulate matter (RSP) concentrations (mg/m³ for LEV:HEPA-, LEV:Shop-vac-, wet-, and uncontrolled grinding, while GV was off/on, were 1.58/0.63, 7.20/1.15, 9.52/4.13, and 152/47.8, respectively. GM concentrations of RSP using 100-125 mm and 180 mm grinding cups were 4.78/1.62 and 22.2/5.06, respectively. GM concentrations of RSP were significantly lower for (1) GV on (70.2%) vs. off, and (2) LEV:HEPA- (98.9%), LEV:Shop-vac- (96.9%) or wet- (92.6%) vs. uncontrolled grinding. Silica dust and RSP were not significantly affected by (1) orientation of grinding surfaces (vertical vs. inclined); (2) water flow rates for wet grinding; (3) length of task-specific sampling time; or, (4) among cup sizes of 100, 115 or 125 mm. No combination of factors or control methods reduced an 8-hr exposure level to below the

  4. Deep geothermics

    International Nuclear Information System (INIS)

    Anon.

    1995-01-01

    The hot-dry-rocks located at 3-4 km of depth correspond to low permeable rocks carrying a large amount of heat. The extraction of this heat usually requires artificial hydraulic fracturing of the rock to increase its permeability before water injection. Hot-dry-rocks geothermics or deep geothermics is not today a commercial channel but only a scientific and technological research field. The Soultz-sous-Forets site (Northern Alsace, France) is characterized by a 6 degrees per meter geothermal gradient and is used as a natural laboratory for deep geothermal and geological studies in the framework of a European research program. Two boreholes have been drilled up to 3600 m of depth in the highly-fractured granite massif beneath the site. The aim is to create a deep heat exchanger using only the natural fracturing for water transfer. A consortium of german, french and italian industrial companies (Pfalzwerke, Badenwerk, EdF and Enel) has been created for a more active participation to the pilot phase. (J.S.). 1 fig., 2 photos

  5. Reducing the Entrainment of Gangue Fines in Low Grade Microcrystalline Graphite Ore Flotation Using Multi-Stage Grinding-Flotation Process

    Directory of Open Access Journals (Sweden)

    Xiaoqing Weng

    2017-03-01

    Full Text Available A suitable grinding fineness and flow-sheet could potentially reduce the mechanical entrainment of gangue minerals in the flotation process of microcrystalline graphite. In this study, the suitable grinding fineness of a commercial graphite ore was estimated by mineralogy analysis and laboratory grind-flotation tests. The target grind size of this ore should be 92% passing 74 μm based on the mineralogical evaluation and the flotation performance. A comparison of a single-stage and a three-stage grinding circuit was conducted. Experimental results demonstrated that the three-stage grinding circuit could effectively improve the separation effect, which was attributed to the reduction of slimes. In the end, a more desirable beneficiation result was obtained with the application of three-stage grinding-flotation process by minimizing gangue entrainment.

  6. Intra-pulp temperature increase of equine cheek teeth during treatment with motorized grinding systems : influence of grinding head position and rotational speed

    OpenAIRE

    Haeussler, Silvia; Luepke, Matthias; Seifert, Hermann; Staszyk, Carsten

    2014-01-01

    BACKGROUND: In equine practice, teeth corrections by means of motorized grinding systems are standard procedure. The heat resulting from that treatment may cause irreparable damage to the dental pulp. It has been shown that a 5.5degreesC temperature rise may cause severe destruction in pulp cells. Hence, the capability to continuously form secondary dentine is lost, and may lead, due to equine-typical occlusal tooth abrasion, to an opening of the pulp cavity.To obtain reliable data on the int...

  7. Research on the Sensorial Quality and Economic Efficiency in Obtaining of a certain Raw Meat Product - Mici Paste

    OpenAIRE

    Claudiu-Dan Salagean; Dorin Tibulca; Radu Marin

    2013-01-01

    Research aimed the sensorial quality connected with the economic efficiency to obtain a certain raw meat product (mici paste) in 4 experimental variants: 1 and 3 variants, with animal raw materials (meat + bacon) and mix of natural spices - fine grinding variant (1) and coarse grinding variant (3) - chopping at the volf through the sieve of 3-4 mm; 2 and 4 variants, with animal raw materials (meat + bacon) + vegetable protein supplements (textured soy protein) + binder (protein + fiber) + add...

  8. Experimental Study on Characteristics of Grinded Graphene Nanofluids with Surfactants

    Directory of Open Access Journals (Sweden)

    HeonJin Seong

    2018-06-01

    Full Text Available In earlier studies, much research has focused on increasing the efficiency of heat exchanger fields. Therefore, in this study, graphene nanofluid was fabricated for use as a heat transfer medium for a heat exchanger. Graphene has excellent electrical conductivity, mechanical properties, and heat transfer properties. It is expected that the heat transfer efficiency will be improved by fabricating the nanofluid. However, graphene is prone to sedimentation, because of its cohesion due to van der Waals binding force. In this experiment, a nanofluid was fabricated with enhanced dispersibility by surfactant and the ball-milling process. The zeta potential, absorbance, and thermal conductivity of the nanofluid were measured. As a result, when using the ratio of 2:1 (graphene:sodium dodecyl sulfate (SDS, a higher thermal conductivity was obtained than in other conditions.

  9. Effect of grinding and polishing on roughness and strength of zirconia.

    Science.gov (United States)

    Khayat, Waad; Chebib, Najla; Finkelman, Matthew; Khayat, Samer; Ali, Ala

    2018-04-01

    The clinical applications of high-translucency monolithic zirconia restorations have increased. Chairside and laboratory adjustments of these restorations are inevitable, which may lead to increased roughness and reduced strength. The influence of grinding and polishing on high-translucency zirconia has not been investigated. The purpose of this in vitro study was to compare the roughness averages (Ra) of ground and polished zirconia and investigate whether roughness influenced strength after aging. High-translucency zirconia disks were milled, sintered, and glazed according to the manufacturer's recommendations. Specimens were randomized to 4 equal groups. Group G received only grinding; groups GPB and GPK received grinding and polishing with different polishing systems; and group C was the (unground) control group. All specimens were subjected to hydrothermal aging in an autoclave at 134°C at 200 kPa for 3 hours. Roughness average was measured using a 3-dimensional (3D) optical interferometer at baseline (Ra1), after grinding and polishing (Ra2), and after aging (Ra3). A biaxial flexural strength test was performed at a rate of 0.5 mm/min. Statistical analyses were performed using commercial software (α=.05). Group G showed a significantly higher mean value of Ra3 (1.96 ±0.32 μm) than polished and glazed groups (P.05). Compared with baseline, the roughness of groups G and GPB increased significantly after surface treatments and after aging, whereas aging did not significantly influence the roughness of groups GPK or C. Group G showed the lowest mean value of biaxial flexural strength (879.01 ±157.99 MPa), and the highest value was achieved by group C (962.40 ±113.84 MPa); no statistically significant differences were found among groups (P>.05). Additionally, no significant correlation was detected between the Ra and flexural strength of zirconia. Grinding increased the roughness of zirconia restorations, whereas proper polishing resulted in smoothness

  10. Spectral analysis of the efficiency of vertical mixing in the deep ocean due to interaction of tidal currents with a ridge running down a continental slope

    Energy Technology Data Exchange (ETDEWEB)

    Ibragimov, Ranis N.; Tartakovsky, Alexandre M.

    2014-10-29

    Efficiency of mixing, resulting from the reflection of an internal wave field imposed on the oscillatory background flow with a three-dimensional bottom topography, is investigated using a linear approximation. The radiating wave field is associated with the spectrum of the linear model, which consists of those mode numbers n and slope values α, for which the solution represents the internal waves of frequencies ω = nω0 radiating upwrad of the topography, where ω0 is the fundamental frequency at which internal waves are generated at the topography. The effects of the bottom topography and the earth’s rotation on the spectrum is analyzed analytically and numerically in the vicinity of the critical slope, which is a slope with the same angle to the horizontal as the internal wave characteristic. In this notation, θ is latitude, f is the Coriolis parameter and N is the buoyancy frequency, which is assumed to be a constant, which corresponds to the uniform stratification.

  11. Mechanochemical Ring-Opening Polymerization of Lactide: Liquid-Assisted Grinding for the Green Synthesis of Poly(lactic acid) with High Molecular Weight.

    Science.gov (United States)

    Ohn, Nuri; Shin, Jihoon; Kim, Sung Sik; Kim, Jeung Gon

    2017-09-22

    Mechanochemical polymerization of lactide is carried out by using ball milling. Mechanical energy from collisions between the balls and the vessel efficiently promotes an organic-base-mediated metal- and solvent-free solid-state polymerization. Investigation of the parameters of the ball-milling synthesis revealed that the degree of lactide ring-opening polymerization could be modulated by the ball-milling time, vibration frequency, mass of the ball media, and liquid-assisted grinding. Liquid-assisted grinding was found to be an especially important factor for achieving a high degree of mechanochemical polymerization. Although polymer-chain scission from the strong collision energy prevented mechanical-force-driven high-molecular-weight polymer synthesis, the addition of only a small amount of liquid enabled sufficient energy dissipation and poly(lactic acid) was thereby obtained with a molecular weight of over 1×10 5  g mol -1 . © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Ontology-based coupled optimisation design method using state-space analysis for the spindle box system of large ultra-precision optical grinding machine

    Science.gov (United States)

    Wang, Qianren; Chen, Xing; Yin, Yuehong; Lu, Jian

    2017-08-01

    With the increasing complexity of mechatronic products, traditional empirical or step-by-step design methods are facing great challenges with various factors and different stages having become inevitably coupled during the design process. Management of massive information or big data, as well as the efficient operation of information flow, is deeply involved in the process of coupled design. Designers have to address increased sophisticated situations when coupled optimisation is also engaged. Aiming at overcoming these difficulties involved in conducting the design of the spindle box system of ultra-precision optical grinding machine, this paper proposed a coupled optimisation design method based on state-space analysis, with the design knowledge represented by ontologies and their semantic networks. An electromechanical coupled model integrating mechanical structure, control system and driving system of the motor is established, mainly concerning the stiffness matrix of hydrostatic bearings, ball screw nut and rolling guide sliders. The effectiveness and precision of the method are validated by the simulation results of the natural frequency and deformation of the spindle box when applying an impact force to the grinding wheel.

  13. Growth, water use efficiency, and adaptive features of the tree legume tagasaste (Chamaecytisus proliferus Link.) on deep sands in south-western Australia

    International Nuclear Information System (INIS)

    Lefroy, E. C.; Pate, J. S.

    2001-01-01

    Four-year-old tagasaste trees in dense plantation and wide-spaced alley cropping layouts at Moora, Western Australia, were cut back to 0.6 m high and their patterns of coppice regrowth and water use monitored over 3 years. Trees reached a permanent fresh watertable at 5 m depth by means of deeply penetrating sinker roots. Dry matter (DM) accumulation and transpiration loss were closely similar at the 2 planting densities despite higher soil water contents in alley plots. Yearly transpiration at plantation density amounted to 0.55 and 0.63 of Penman-Montieth potential evapotranspiration (E 0 ) in the second and third years, respectively. Mean water use efficiency over the 3 years was 247 L/kg DM, compared with values in the range 186-320 L/kg for younger pot-and column-grown trees. Using a combination of neutron moisture metre (NMM) assays of soil moisture and deuterium: hydrogen ratios of groundwater and xylem water of tagasaste and annual weeds, it was shown that trees became increasingly dependent on groundwater over time and had the capacity to switch rapidly between soil and groundwater sources. Seasonal changes in carbon isotope composition of new shoot tip dry matter indicated that plantation trees were less stressed than alley trees by the third summer as they adapted to heavy dependence on groundwater. In the third season, when plantation trees were transpiring at rates equivalent to 2.3 times annual rainfall, NMM profiles and time domain reflectometry (TDR) assays indicated that no free drainage occurred and that trees were capable of hydraulically lifting groundwater to near surface soil in the dry season. Additional adaptive features of importance to this environment included heat stress induced leaf shedding, development of perennial root nodules on lower parts of tap roots, and an ability to respond in summer to artificial irrigation or a seasonal rainfall by rapidly increasing transpiration 2-3-fold to values equalling E 0 . Copyright (2001) CSIRO

  14. Grinding and polishing instead of sectioning for the tissue samples with a graft: Implications for light and electron microscopy.

    Science.gov (United States)

    Mukhamadiyarov, Rinat A; Sevostyanova, Victoria V; Shishkova, Daria K; Nokhrin, Andrey V; Sidorova, Olga D; Kutikhin, Anton G

    2016-06-01

    A broad use of the graft replacement requires a detailed investigation of the host-graft interaction, including both histological examination and electron microscopy. A high quality sectioning of the host tissue with a graft seems to be complicated; in addition, it is difficult to examine the same tissue area by both of the mentioned microscopy techniques. To solve these problems, we developed a new technique of epoxy resin embedding with the further grinding, polishing, and staining. Graft-containing tissues prepared by grinding and polishing preserved their structure; however, sectioning frequently required the explantation of the graft and led to tissue disintegration. Moreover, stained samples prepared by grinding and polishing may then be assessed by both light microscopy and backscattered scanning electron microscopy. Therefore, grinding and polishing outperform sectioning when applied to the tissues with a graft. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Deep smarts.

    Science.gov (United States)

    Leonard, Dorothy; Swap, Walter

    2004-09-01

    When a person sizes up a complex situation and rapidly comes to a decision that proves to be not just good but brilliant, you think, "That was smart." After you watch him do this a few times, you realize you're in the presence of something special. It's not raw brainpower, though that helps. It's not emotional intelligence, either, though that, too, is often involved. It's deep smarts. Deep smarts are not philosophical--they're not"wisdom" in that sense, but they're as close to wisdom as business gets. You see them in the manager who understands when and how to move into a new international market, in the executive who knows just what kind of talk to give when her organization is in crisis, in the technician who can track a product failure back to an interaction between independently produced elements. These are people whose knowledge would be hard to purchase on the open market. Their insight is based on know-how more than on know-what; it comprises a system view as well as expertise in individual areas. Because deep smarts are experienced based and often context specific, they can't be produced overnight or readily imported into an organization. It takes years for an individual to develop them--and no time at all for an organization to lose them when a valued veteran walks out the door. They can be taught, however, with the right techniques. Drawing on their forthcoming book Deep Smarts, Dorothy Leonard and Walter Swap say the best way to transfer such expertise to novices--and, on a larger scale, to make individual knowledge institutional--isn't through PowerPoint slides, a Web site of best practices, online training, project reports, or lectures. Rather, the sage needs to teach the neophyte individually how to draw wisdom from experience. Companies have to be willing to dedicate time and effort to such extensive training, but the investment more than pays for itself.

  16. Bending Distortion Analysis of a Steel Shaft Manufacturing Chain from Cold Drawing to Grinding

    Science.gov (United States)

    Dias, Vinicius Waechter; da Silva Rocha, Alexandre; Zottis, Juliana; Dong, Juan; Epp, Jérémy; Zoch, Hans Werner

    2017-04-01

    Shafts are usually manufactured from bars that are cold drawn, cut machined, induction hardened, straightened, and finally ground. The main distortion is characterized by bending that appears after induction hardening and is corrected by straightening and/or grinding. In this work, the consequence of the variation of manufacturing parameters on the distortion was analyzed for a complete manufacturing route for production of induction hardened shafts made of Grade 1045 steel. A DoE plan was implemented varying the drawing angle, cutting method, induction hardening layer depth, and grinding penetration depth. The distortion was determined by calculating curvature vectors from dimensional analysis by 3D coordinate measurements. Optical microscopy, microhardness testing, residual stress analysis, and FEM process simulation were used to evaluate and understand effects of the main carriers of distortion potential. The drawing process was identified as the most significant influence on the final distortion of the shafts.

  17. The effect of bean origin and temperature on grinding roasted coffee

    Science.gov (United States)

    Uman, Erol; Colonna-Dashwood, Maxwell; Colonna-Dashwood, Lesley; Perger, Matthew; Klatt, Christian; Leighton, Stephen; Miller, Brian; Butler, Keith T.; Melot, Brent C.; Speirs, Rory W.; Hendon, Christopher H.

    2016-01-01

    Coffee is prepared by the extraction of a complex array of organic molecules from the roasted bean, which has been ground into fine particulates. The extraction depends on temperature, water chemistry and also the accessible surface area of the coffee. Here we investigate whether variations in the production processes of single origin coffee beans affects the particle size distribution upon grinding. We find that the particle size distribution is independent of the bean origin and processing method. Furthermore, we elucidate the influence of bean temperature on particle size distribution, concluding that grinding cold results in a narrower particle size distribution, and reduced mean particle size. We anticipate these results will influence the production of coffee industrially, as well as contribute to how we store and use coffee daily. PMID:27086837

  18. The effect of bean origin and temperature on grinding roasted coffee

    Science.gov (United States)

    Uman, Erol; Colonna-Dashwood, Maxwell; Colonna-Dashwood, Lesley; Perger, Matthew; Klatt, Christian; Leighton, Stephen; Miller, Brian; Butler, Keith T.; Melot, Brent C.; Speirs, Rory W.; Hendon, Christopher H.

    2016-04-01

    Coffee is prepared by the extraction of a complex array of organic molecules from the roasted bean, which has been ground into fine particulates. The extraction depends on temperature, water chemistry and also the accessible surface area of the coffee. Here we investigate whether variations in the production processes of single origin coffee beans affects the particle size distribution upon grinding. We find that the particle size distribution is independent of the bean origin and processing method. Furthermore, we elucidate the influence of bean temperature on particle size distribution, concluding that grinding cold results in a narrower particle size distribution, and reduced mean particle size. We anticipate these results will influence the production of coffee industrially, as well as contribute to how we store and use coffee daily.

  19. Effect of grinding and polishing on near-surface phase transformations in zirconia

    International Nuclear Information System (INIS)

    Reed, J.S.; Lejus, A.M.

    1977-01-01

    The transformation of near-surface material on grinding and polishing has been investigated in sintered zirconia of 1 μm grain size and 99 percent density containing 4.5 and 7.0 mole percent Y 2 O 3 . Rough wet and dry grinding transformed about 20 percent cubic phase into 18 percent tetragonal and 2 percent monoclinic in material initially 47 percent cubic and 53 percent tetragonal (4.5 mole percent Y 2 O 3 ) but no change of phase in material that was fully cubic (7.0 mole percent Y 2 O 3 ). Annealing and polishing reduced lattice strain but only polishing reduced the concentration of monoclinic and tetragonal phases. Microhardness studies indicated that lattice strain and the phase transformations increased the penetration hardness to a depth of about 4 μm

  20. Effect of Grinding Fineness of Fly Ash on the Properties of Geopolymer Foam

    Directory of Open Access Journals (Sweden)

    Szabó R.

    2017-06-01

    Full Text Available Present paper deals with the development of geopolymer foam prepared from ground F class power station fly ash. The effect of the fly ash fineness on the rheology of the geopolymer paste and the foam properties have been investigated. The raw fly ash was ground in a ball mill for various duration, 5, 10, 20, 30, 60 and 120 min. Geopolymer paste was prepared from the raw and ground fly ash with NaOH – sodium silicate mixture as alkaline activator. Geopolymer foam production was made using H2O2 as foaming agent. Additionally, the geopolymer material structure was investigated by Fourier transform infrared spectrometer, the foam cell structure was monitored using optical microscopy. The rheological behaviour of the geopolymer paste changed due to the grinding of fly ash (from Bingham plastic to Newtonian liquid. Grinding of fly ash has a significant effect on the physical properties as well as on the cell structure of the geopolymer foam.