WorldWideScience

Sample records for fixed cutter grinders

  1. Test Plan for Evaluating Hammer and Fixed Cutter Grinders Using Multiple Varieties and Moistures of Biomass Feedstock

    Energy Technology Data Exchange (ETDEWEB)

    Not listed

    2007-07-01

    Biomass preprocessing is a critical operation in the preparation of feedstock for the front-end of a cellulosic ethanol biorefinery. Its purpose is to chop, grind, or otherwise format the biomass material into a suitable feedstock for optimum conversion to ethanol and other bioproducts. Without this operation, the natural size, bulk density, and flowability characteristics of harvested biomass would decrease the capacities and efficiencies of feedstock assembly unit operations and biorefinery conversion processes to the degree that programmatic cost targets could not be met. The preprocessing unit operation produces a bulk flowable material that 1) improves handling and conveying efficiencies throughout the feedstock assembly system and biorefinery 2) increases biomass surface areas for improved pretreatment efficiencies, 3) reduces particle sizes for improved feedstock uniformity and density, and 4) fractionates structural components for improved compositional quality. The Idaho National Laboratory (INL) is tasked with defining the overall efficiency/effectiveness of current commercial hammer and fixed cutter grinding systems and other connecting systems such as harvest and collection, storage, transportation, and handling for a wide variety of feedstock types used in bioethanol or syngas production. This test plan details tasks and activities for two separate full-scale grinding tests: Material Characterization Test and Machine Characterization Test. For the Material Characterization Test, a small amount (~5-7 tons each) of several feedstock varieties will be ground. This test will define the fractionation characteristics of the grinder that affect the bulk density, particle size distribution, and quality of the size reduced biomass resulting from different separation screen sizes. A specific screen size will be selected based on the characteristics of the ground material. The Machine Characterization Test will then use this selected screen to grind several 30

  2. Classification system adopted for fixed cutter bits

    Energy Technology Data Exchange (ETDEWEB)

    Winters, W.J.; Doiron, H.H.

    1988-01-01

    The drilling industry has begun adopting the 1987 International Association of Drilling Contractors' (IADC) method for classifying fixed cutter drill bits. By studying the classification codes on bit records and properly applying the new IADC fixed cutter dull grading system to recently run bits, the end-user should be able to improve the selection and usage of fixed cutter bits. Several users are developing databases for fixed cutter bits in an effort to relate field performance to some of the more prominent bit design characteristics.

  3. Measuring the effects of cutter suction dredge operating parameters on minor losses due to fixed screens installed at the suction inlet

    OpenAIRE

    Lewis, Joshua Mark

    2014-01-01

    CIVINS One of the most efficient and versatile types of modern dredges is the cutter suction dredge. Specific regulations mandate the placement of screens over the suction mouth during dredging operations to prevent ordnance, wildlife, and other debris from entering the system; however, these screens change the operational capability of the dredge in the form of an additional minor loss. The goal of this experiment was to determine the effects of different dredge operating p...

  4. 7 CFR 58.708 - Grinders or shredders.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Grinders or shredders. 58.708 Section 58.708 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards....708 Grinders or shredders. The grinders or shredders used in the preparation of the trimmed...

  5. Gas tungsten arc welder with electrode grinder

    Science.gov (United States)

    Christiansen, David W.; Brown, William F.

    1984-01-01

    A welder for automated closure of fuel pins by a gas tungsten arc process in which a rotating length of cladding is positioned adjacent a welding electrode in a sealed enclosure. An independently movable axial grinder is provided in the enclosure for refurbishing the used electrode between welds.

  6. Kinematics analysis of a robotic rock grinder

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    With the aim to discover water, life and resources in other planets, robotic sampling instrument is a crucial part of the space exploration robot. To remove dusty and weathered surfaces and expose the fresh rock underneath the planetary surface, a robotic rock grinder is considered to replace the geologist's rock hammer to carry out the geological investigation. A primary prototype of the robotic rock grinder with three degrees of freedom has been developed in this paper. Planetary transmission system is used in the grinding driving system with two inputs (rotation motor and revolution motor) and two outputs (grinding wheel and cutting brush). The grinding wheel with two teeth has been used to abrade the rock. The cutting brush is used to sweep the debris. The third actuator is to feed the grinding system. Kinematics of the grinding system has been analyzed. To get a continuous and smooth fresh face over the rock, grinding trajectory of the grinding wheel has been discussed and planned. Lastly, abrasion experiments have been made to testify the feasibility and the basic function of this system.

  7. Cutting capacity of PDC cutters in very hard rock

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    An experimental programm of investigating the cutting capacity of PDC flat cutters in very hard rock has been performed.Experiments include both the cutting of PDC fixed at different angles on the granite core or bar and linear cutting with different static thrust on the block of granite.The effects of the rough degree of rock surface,cutting angles,and static thrust on the cutting capacity of PDC in very hard rock were investigated and analyzed.The results show that the single mode of rotary drilling using PDC cutters is not applied for very hard rocks.

  8. 33 CFR 151.75 - Grinders or comminuters.

    Science.gov (United States)

    2010-07-01

    ... BALLAST WATER Implementation of MARPOL 73/78 and the Protocol on Environmental Protection to the Antarctic Treaty as it Pertains to Pollution from Ships Garbage Pollution and Sewage § 151.75 Grinders...

  9. Scheduling Coast Guard District Cutters

    Science.gov (United States)

    1992-09-01

    DESCRIPTION ..... ............ .. 14 D. COSTS, PENALTIES, AND MEASURES OF EFFECTIVENESS 15 iv IV . COMPUTATIONAL EXPERIENCE ............ 19 A. TEST PROBLEMS...used. Using the model of Chapter III, computational performance for a year’s worth of actual data from the First District is presented in Chapter IV ...2G, B-2NY, B-2SAR, C); t - week the cutter assumes the patrol status. COSTO - cost of scheduling cutter i to patrol k; (1 if ship i is available for

  10. Development of two-stage grain grinder

    Directory of Open Access Journals (Sweden)

    V. N. Trubnikov

    2016-01-01

    Full Text Available The most important task in the development of the diet of farm animals feeding is a selection of the most balanced in its composition and most nutritious feeds, which are safe and meet all the necessary requirements at the same time. To evaluate the productive value of feeds and their effectiveness the rate of food productive action η was proposed. This ratio reflects the productive part of the total value of the exchange energy of the daily feed ration and is an essential criterion of the feed quality indicators. In the feed rations of animals the most expensive, but energy-rich feed is a mixed fodder, a mixture of grinded seeds of agricultural crops and protein, mineral and vitamin additives. In the diet for its nutritional value, this feed product is for cattle – 50, pigs – 60… 100 and birds – 100%. The basic operation in the production of mixed fodder is seeds grinding, i.e. their destruction under the influence of external forces, exceeding the forces of molecular adhesion of the grains particles. To grind the grain different ways are used: chopping, grinding, impact «in flight», crushing, etc. In the production of mixed fodder on the existing production equipment, there is the problem of getting the grain mixed fodder the necessary degree of grinding and uniform in its particle size distribution at the same time. When receiving too coarse grinding there is a problem of difficult digestibility of mixed fodder by farm animals. Moreover grinding process is accompanied by a high energy consumption. Grain grinder, the principle of which is based on the implementation of two ways of grinding grain: splitting and impact «in flight» is proposed. The proposed constructive solutions allow to obtain a high-performance technical means for crushing seeds of crops, as well as reduce energy costs that arise during the course of the process of obtaining of mixed fodder. The methodology justification of degree of grain grinding by

  11. Surface shape control of the workpiece in a double-spindle triple-workstation wafer grinder

    Science.gov (United States)

    Xianglong, Zhu; Renke, Kang; Zhigang, Dong; Guang, Feng

    2011-10-01

    Double-spindle triple-workstation (DSTW) ultra precision grinders are mainly used in production lines for manufacturing and back thinning large diameter (>= 300 mm) silicon wafers for integrated circuits. It is important, but insufficiently studied, to control the wafer shape ground on a DSTW grinder by adjusting the inclination angles of the spindles and work tables. In this paper, the requirements of the inclination angle adjustment of the grinding spindles and work tables in DSTW wafer grinders are analyzed. A reasonable configuration of the grinding spindles and work tables in DSTW wafer grinders are proposed. Based on the proposed configuration, an adjustment method of the inclination angle of grinding spindles and work tables for DSTW wafer grinders is put forward. The mathematical models of wafer shape with the adjustment amount of inclination angles for both fine and rough grinding spindles are derived. The proposed grinder configuration and adjustment method will provide helpful instruction for DSTW wafer grinder design.

  12. The Research of CNC Machining Cutter Choice Based on CAXA

    Institute of Scientific and Technical Information of China (English)

    RUAN Xiao-guang; YUAN Si-cong; CAI An-jiang; ZHANG Dang-fei

    2011-01-01

    The article introduces the unique characteristics of CNC machining center cutter compared to traditional cutters, analyzes the choice of CNC machining cutter and factors of choice. Meanwhile, proved by the examples with manufacture software CAXA2004, the correct choice of CNC machining center cutter can give full play to the advantages of CNC machining and improve the economic efficiency and production levels of enterprises.

  13. Wholly smoothing cutter orientations for five-axis NC machining based on cutter contact point mesh

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Cutting forces with respect to different cutter orientations are analyzed for five-axis NC machining of a ball-end cutter.A measure is then defined to quantify the effects of cutter orientation variation.According to the measure,a novel model and algorithm are proposed to wholly optimize cutter orientations based on a cutter contact(CC) point mesh.The method has two advantages.One is that the cutter orientation smoothnesses along the feed direction and pick-feed direction are both wholly optimized.The other is that only the accessibility cones of mesh points are required to compute and the computation efficiency is improved.These advantages are shown by simulating the machining efficiency,the stability of feed velocities and the smoothness of cutting force.A computational example and a cutting experiment are finally given to illustrate the validity of the proposed method.

  14. Bolt Cutter Blade's Imprint in Toolmarks Examination.

    Science.gov (United States)

    Volkov, Nikolai; Finkelstein, Nir; Novoselsky, Yehuda; Tsach, Tsadok

    2015-11-01

    Bolt cutters are known as cutting tools which are used for cutting hard objects and materials, such as padlocks and bars. Bolt cutter blades leave their imprint on the cut objects. When receiving a cut object from a crime scene, forensic toolmarks examiners can determine whether the suspected cutting tool was used in a specific crime or not based on class characteristic marks and individual marks that the bolt cutter blades leave on the cut object. The paper presents preliminary results of a study on ten bolt cutters and suggests a quick preliminary examination-the comparison between the blade thickness and the width of the imprint left by the tool on the cut object. Based on the comparison result, if there is not a match, the examiner can eliminate the feasibility of the use of the suspected cutting tool in a specific crime. This examination simplifies and accelerates the comparison procedure.

  15. Quantum Mechanics and the Cookie Cutter Paradigm

    CERN Document Server

    Mohrhoff, U

    2000-01-01

    What has so far prevented us from decrypting quantum mechanics is the Cookie Cutter Paradigm, according to which the world's synchronic multiplicity derives from surfaces that carve up space in the manner of three-dimensional cookie cutters. This insidious notion is shown to be rooted in our neurophysiological make-up. An effort is made to liberate the physical world from this innate fallacy.

  16. Jam-Resistant Cutters For Emergency Separation

    Science.gov (United States)

    Ordonez, Arturo C.; Yee, Ronald N.

    1990-01-01

    Pyrotechnic emergency-separation system includes shaped explosive charges that sever pair of hinges. System ensures reliable opening of escape hatch. Two pairs of cutters provided for each hinge so if one pair of cutters fails, other completes job. Pressure of explosions vented to prevent charge holders from fragmenting and forming sharp edges around open hatch. Exit slide deployed without tearing. Before detonation L-shaped retainers bear on hinge. After denonation, retainers fold outward to facilitate egress of severed hinges.

  17. Penetrating head injury from angle grinder: A cautionary tale.

    Science.gov (United States)

    Senthilkumaran, S; Balamurgan, N; Arthanari, K; Thirumalaikolundusubramanian, P

    2010-01-01

    Penetrating cranial injury is a potentially life-threatening condition. Injuries resulting from the use of angle grinders are numerous and cause high-velocity penetrating cranial injuries. We present a series of two penetrating head injuries associated with improper use of angle grinder, which resulted in shattering of disc into high velocity missiles with reference to management and prevention. One of those hit on the forehead of the operator and the other on the occipital region of the co-worker at a distance of five meters. The pathophysiological consequence of penetrating head injuries depends on the kinetic energy and trajectory of the object. In the nearby healthcare center the impacted broken disc was removed without realising the consequences and the wound was packed. As the conscious level declined in both, they were referred. CT brain revealed fracture in skull and changes in the brain in both. Expeditious removal of the penetrating foreign body and focal debridement of the scalp, skull, dura, and involved parenchyma and Watertight dural closure were carried out. The most important thing is not to remove the impacted foreign body at the site of accident. Craniectomy around the foreign body, debridement and removal of foreign body without zigzag motion are needed. Removal should be done following original direction of projectile injury. The neurological sequelae following the non missile penetrating head injuries are determined by the severity and location of initial injury as well as the rapidity of the exploration and fastidious debridement.

  18. Penetrating head injury from angle grinder: A cautionary tale

    Directory of Open Access Journals (Sweden)

    S Senthilkumaran

    2010-01-01

    Full Text Available Penetrating cranial injury is a potentially life-threatening condition. Injuries resulting from the use of angle grinders are numerous and cause high-velocity penetrating cranial injuries. We present a series of two penetrating head injuries associated with improper use of angle grinder, which resulted in shattering of disc into high velocity missiles with reference to management and prevention. One of those hit on the forehead of the operator and the other on the occipital region of the co-worker at a distance of five meters. The pathophysiological consequence of penetrating head injuries depends on the kinetic energy and trajectory of the object. In the nearby healthcare center the impacted broken disc was removed without realising the consequences and the wound was packed. As the conscious level declined in both, they were referred. CT brain revealed fracture in skull and changes in the brain in both. Expeditious removal of the penetrating foreign body and focal debridement of the scalp, skull, dura, and involved parenchyma and Watertight dural closure were carried out. The most important thing is not to remove the impacted foreign body at the site of accident. Craniectomy around the foreign body, debridement and removal of foreign body without zigzag motion are needed. Removal should be done following original direction of projectile injury. The neurological sequelae following the non missile penetrating head injuries are determined by the severity and location of initial injury as well as the rapidity of the exploration and fastidious debridement.

  19. Study of the Interaction Model of PDC Cutters with Rock

    Directory of Open Access Journals (Sweden)

    Wang Jiajun

    2014-06-01

    Full Text Available The existing PDC cutters with rock interaction models does not match the actual drilling condition, because WOB can’t be loaded on their equipment, the influence of the cutting velocity on the force of cutters doesn’t be considered. A drilling experiment was carried out in the experimental device in which cutters can be loaded WOB. The relationship of cutting area, cutting speed, back dip angle of PDC cutter and rock performance with the force of PDC cutter were considered. The multiple nonlinear regression analysis were done on the basis of the experimental data, a new cutter-rock interaction model was established. The cutter area is the principal component influencing the force of cutters though the cluster analysis and principal component analysis. It is a logarithmic relationship between cutting velocity and the force of cutter, the theory of particle dynamics confirms this relationship.

  20. Surface shape control of the workpiece in a double-spindle triple-workstation wafer grinder

    Institute of Scientific and Technical Information of China (English)

    Zhu Xianglong; Kang Renke; Dong Zhigang; Feng Guang

    2011-01-01

    Double-spindle triple-workstation (DSTW) ultra precision grinders are mainly used in production lines for manufacturing and back thinning large diameter (≥ 300 mm) silicon wafers for integrated circuits.It is important,but insufficiently studied,to control the wafer shape ground on a DSTW grinder by adjusting the inclination angles of the spindles and work tables.In this paper,the requirements of the inclination angle adjustment of the grinding spindles and work tables in DSTW wafer grinders are analyzed.A reasonable configuration of the grinding spindles and work tables in DSTW wafer grinders are proposed.Based on the proposed configuration,an adjustment method of the inclination angle of grinding spindles and work tables for DSTW wafer grinders is put forward.The mathematical models of wafer shape with the adjustment amount of inclination angles for both fine and rough grinding spindles are derived.The proposed grinder configuration and adjustment method will provide helpful instruction for DSTW wafer grinder design.

  1. Failure modes of PDC cutters under different loads

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The capability of several types of flat PDC cutters to withstand combined loads were tested and evaluated by the impact and cutting of single PDC cutter on granite in a linear impact-cutting table.The primary failure modes of PDC cutters withstading different combined loads wrer investigated and analyzed.The suggestions of enhancing PDC cutters to be suitables for drilling very hard rock have been made.

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

    Science.gov (United States)

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

    1967-01-01

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

  3. Systemic sclerosis in a stone cutter

    Directory of Open Access Journals (Sweden)

    Khanna N

    1997-01-01

    Full Text Available Several occupational hazards especially exposure to silica have been implicated as eliciting factors for the development of scleroderma-like disorders. We here report a case of manual stone-cutter who developed progressive scleroderma, interstitial lung disease and decreased oesophageal motility after several years of exposure to silica dust.

  4. 40 CFR 1065.265 - Nonmethane cutter.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 32 2010-07-01 2010-07-01 false Nonmethane cutter. 1065.265 Section 1065.265 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS ENGINE-TESTING PROCEDURES Measurement Instruments Hydrocarbon Measurements § 1065.265 Nonmethane...

  5. Dimensions of cookie-cutter-like sets

    Institute of Scientific and Technical Information of China (English)

    马际华; 饶辉; 文志英

    2001-01-01

    The cookie-cutter-like sets are defined as the limit sets of a sequence of classical cookiecutter mappings. By introducing Gibbs-like measures, we study the dimensions, Hausdorff and packing measures of the CC-like sets, and then discuss the continuous dependence of the dimensions.

  6. Fatigue and Model Analysis of the CNC Cylindrical Grinder

    Directory of Open Access Journals (Sweden)

    Lin Jui-Chang

    2016-01-01

    Full Text Available The purpose of this study is to lower deviation of workpiece by meeting high stability and rigidity to prevent the resonance in producing procedure of the CNC universal cylindrical grinding machine. Using finite element analysis software ABAQUS in grinder machine tools for numerical simulation of several analyses for the following: structural rigidity analysis, optimized design, vibration frequency analysis and fatigue damage analysis. This work aims on state of the transmission of outer diameter spindle to proceed in stress and fatigue life analysis by FE-SAFE Subroutine. The max values of equivalent stress and average amount of displacement in structural rigidity analysis are 0.67(Mpa and 0.92(µm. Optimization design effectively reducing extreme value of stress, the largest decline of about 5.43%. Modal analysis compared with the experimental, the average error percentage was less than 10% of parts. The whole structure error does not exceed 3%. The fatigue life of approximately 1,193,988 times, estimates into real life time can use more than sixty years, from the viewpoint of structural strength, spindle has a good high breaking strength is designed to be safe.

  7. ANALISA FAKTOR PENYEBAB KEGAGALAN MESIN GRINDER PADA PROSES PRODUKSI PLASTIC FILM DI PT. MUTIARA HEXAGON

    Directory of Open Access Journals (Sweden)

    Imam Hidayat

    2013-10-01

    Full Text Available Bila suatu mesin memiliki tingkat kegagalan yang tinggi, maka perlu dilakukan analisis mengenai  penyebab  –  penyebab  kegagalan  tersebut  hingga  ke  akar  permasalahannya sehingga dapat menentukan tindakan yang sesuai untuk meningkatkan kinerja suatu mesin. PT. Mutiara Hexagon merupakan sebuah perusahaan yang bergerak dibidang industri pembuatan plastik  kemasan.  Dalam  line  pembuatan lembaran film  diperlukan mesin  CPP  (Cast  Poly Propylene Machine dan mesin grinder dalam prosesnya. Pada penelitian yang dilakukan di PT. Mutiara Hexagon, terdapat beberapa kegagalan yang terjadi pada mesin grinder pada proses produksi plastic film, sehingga menyebabkan seluruh line pada divisi film mengalami downtime. Tujuan dari penelitian ini adalah untuk melakukan analisa mengenai faktor penyebab kegagalan mesin grinder, penulis melakukan observasi secara langsung dan melihat proses produksi plastic film.Penulis menggunakan metode Failure Effect and Mode Analysis (FMEA dan Fault Tree Analysis (FTA. Penerapan analisis Failure Effect and  Mode Analysis (FMEA dapat menentukan sejauh mana tingkat kegagalan terjadi. Dari hasil analisis FMEA kemudian dapat dilanjutkan dengan menggunakan Fault Tree Analysis (FTA guna mengetahui lebih lanjut penyebab-penyebab dasar suatu kegagalan.Dari hasil perhitungan nilai Risk Priority Number (RPN pada tiap-tiap kegagalan yang terjadi  diantaranya yang  paling  tinggi  adalah kegagalan mesin  grinder rusak  dengan nilai kegagalannya mencapai 120. Kemudian dianalisa penyebab kegagalan tersebut dengan menggunakan metode FTA di dapatkan minimal cut sets yaitu: as grinder patah, katup hisap blower terbuka terlalu besar, kegagalan pada motor blower, baut pada dudukan pisau patah, pisau tumpul dan human error. Berdasarkan nilai probabilitas masing-masing cut set didapatkan nilai probabilitas kegagalan grinder periode 1 Juni 2012 -1 Juni 2013 mencapai 60%.

  8. U.S. Coast Guard Cutter Procurement Lessons Impacts on the Offshore Patrol Cutter (OPC) Program Affordability

    Science.gov (United States)

    2015-12-01

    Sponsored Report Series U.S. Coast Guard Cutter Procurement Lessons’ Impacts on the Offshore Patrol Cutter (OPC) Program Affordability December 2015...School of Business & Public Policy - i - Naval Postgraduate School ABSTRACT The U.S. Coast Guard’s upcoming acquisition of the Offshore Patrol...School NPS-AM-16-012 Acquisition Research Program Sponsored Report Series U.S. Coast Guard Cutter Procurement Lessons’ Impacts on the Offshore

  9. Reusable Hot-Wire Cable Cutter

    Science.gov (United States)

    Pauken, Michael T.; Steinkraus, Joel M.

    2010-01-01

    During the early development stage of balloon deployment systems for missions, nichrome wire cable cutters were often used in place of pyro-actuated cutters. Typically, a nichrome wire is wrapped around a bundle of polymer cables with a low melting point and connected to a relay-actuated electric circuit. The heat from the nichrome reduces the strength of the cable bundle, which quickly breaks under a mechanical load and can thus be used as a release mechanism for a deployment system. However, the use of hand-made heated nichrome wire for cutters is not very reliable. Often, the wrapped nichrome wire does not cut through the cable because it either pulls away from its power source or does not stay in contact with the cable being cut. Because nichrome is not readily soldered to copper wire, unreliable mechanical crimps are often made to connect the nichrome to an electric circuit. A self-contained device that is reusable and reliable was developed to sever cables for device release or deployment. The nichrome wire in this new device is housed within an enclosure to prevent it from being damaged by handling. The electric power leads are internally connected within the unit to the nichrome wire using a screw terminal connection. A bayonet plug, a quick and secure method of connecting the cutter to the power source, is used to connect the cutter to the power leads similar to those used in pyro-cutter devices. A small ceramic tube [0.25-in. wide 0.5-in. long (.6.4-mm wide 13-mm long)] houses a spiraled nichrome wire that is heated when a cable release action is required. The wire is formed into a spiral coil by wrapping it around a mandrel. It is then laid inside the ceramic tube so that it fits closely to the inner surface of the tube. The ceramic tube provides some thermal and electrical insulation so that most of the heat generated by the wire is directed toward the cable bundle in the center of the spiral. The ceramic tube is cemented into an aluminum block, which

  10. 7 CFR 29.1164 - Cutters (C Group).

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Cutters (C Group). 29.1164 Section 29.1164 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing.... C4KM—Fair Quality Variegated Mixed Cutters Unripe, close leaf structure, medium body, normal width,...

  11. Coast Guard Cutter Procurement: Background and Issues for Congress

    Science.gov (United States)

    2016-09-16

    commissioned into service on August 8, 2015). 16 The sixth, seventh, and eighth are under construction and scheduled for delivery in 2016, 2018, and...... Service Summary The Coast Guard’s acquisition program of record (POR) calls for procuring 8 National Security Cutters (NSCs), 25 Offshore Patrol Cutters

  12. Production Machine Shop Employment Competencies. Part Two: Saws, Drills, and Grinders.

    Science.gov (United States)

    Bishart, Gus; Werner, Claire

    Competencies for production machine shop are provided for the second of four topic areas: saws, drills, and grinders. Each competency appears in a one-page format. It is presented as a goal statement followed by one or more "indicator" statements, which are performance objectives describing an ability that, upon attainment, will…

  13. On-line, proximate analysis of ground beef directly at a meat grinder outlet.

    Science.gov (United States)

    Isaksson, T; Nilsen, B N; Tøgersen, G; Hammond, R P; Hildrum, K I

    1996-07-01

    The fat, moisture and protein contents of ground beef were determined on-line by a diffuse reflectance near infrared (NIR) spectroscopy instrument at the outlet of a meat grinder. Beef samples in the range of 6.2-21.7% fat, 59.6-72.9% moisture and 18.1-20.7% protein were studied. Calibrations from samples ground with hole diameters of 4, 8, 13 or 19 mm in the grinder plate were validated. In addition, calibrations of combinations of these samples from the different hole diameters were validated. Prediction errors, expressed as root mean square error of cross validation of the beef samples, were 0.73-1.50% for fat, 0.75-1.33% for moisture and 0.23-0.32% for protein, depending on the hole diameter of the grinder plate. Calibrations from samples ground with the smallest hole diameters gave lowest prediction errors. The present prediction error results are only slightly higher compared to reported prediction error results using conventional at- and off-line NIR instruments. It is concluded that the on-line NIR prediction results were acceptable for samples ground with grinder plates of 4, 8 or 13 mm hole diameter.

  14. Stiffness analysis and comparison of a Biglide parallel grinder with alternative spatial modular parallelograms

    DEFF Research Database (Denmark)

    Wu, Guanglei; Zou, Ping

    2016-01-01

    This paper deals with the stiffness modeling, analysis and comparison of a Biglide parallel grinder with two alternative modular parallelograms. It turns out that the Cartesian stiffness matrix of the manipulator has the property that it can be decoupled into two homogeneous matrices, correspondi...

  15. Treatment of Dropped Nucleus with a 27-Gauge Twin Duty Cycle Vitreous Cutter

    Directory of Open Access Journals (Sweden)

    Akira Watanabe

    2016-01-01

    Full Text Available We report herein a method for the treatment of dropped nucleus during cataract surgery with a 27-gauge twin duty cycle (TDC vitreous cutter. When a TDC vitreous cutter is used, suction flow volume is maintained even when the cutter is driven at a high speed. This enables an Emery-Little grade 3 nucleus that had been difficult to treat with a conventional 27-gauge cutter to be successfully excised using only a vitreous cutter, with no intra- or postoperative complications. A dropped lens during cataract surgery of up to moderate hardness can be removed using a TDC cutter alone with a 27-gauge cutter system.

  16. Comparison of density cutters for snow profile observations

    Science.gov (United States)

    Conger, Steven M.; McClung, David M.

    An investigation was made to estimate the variance, measurement errors and sampling error in currently accepted practices for manual snow density measurement carried out as part of snow profile observations using the available variety of density cutters. A field experiment in dry snow conditions was conducted using a randomized block design to account for layer spatial variability. Cutter types included a 500 cm3 aluminium tube, 200 and 100 cm3 stainless-steel box types, 200 cm3 stainless-steel wedge types and a 100 cm3 stainless-steel tube. Without accounting for variation due to weighing devices, the range of values for 'accepted practice' determined in this study included variation within individual cutters of 0.8-6.2%, variation between cutters of 3-12%, variation between cutter means and layer means of 2-7%, and under-sampling errors of 0-2%. The results of a statistical analysis suggest that snow density measurements taken using various density cutters are significantly different from each other. Without adjustment for under-sampling, and given that the mean of all measurements is the accepted true value of the layer density, variation exclusively between cutter types provides 'accepted practice' measurements that are within 11% of the true density.

  17. Mechanical reprocessing of contaminated bone-cutters according to Lindemann

    OpenAIRE

    Burda, Yvonne

    2016-01-01

    Surgical bone-cutters according to Lindemann play a central role during dental surgical treatments. Bone-cutters become contaminated with blood, saliva, bones and microorganisms. For reuse on patients medical devices have to be reprocessed according to the KRINKO-/BfArM-recommendation from 2012. A "residue-free" cleaning must be ensured for rotating surgical instruments, which is to be investigated. 61 bone-cutters were used as test instruments, made of tungsten-carbide and 63 with a ZrN-hard...

  18. The comparative analysis of rocks’ resistance to forward-slanting disc cutters and traditionally installed disc cutters

    Institute of Scientific and Technical Information of China (English)

    Zhao-Huang Zhang; Sun Fei; Meng Liang

    2016-01-01

    At present, disc cutters of a full face rock tun-nel boring machine are mostly mounted in the traditional way. Practical use in engineering projects reveals that this installation method not only heavily affects the operation life of disc cutters, but also increases the energy consump-tion of a full face rock tunnel boring machine. To straighten out this issue, therefore, a rock-breaking model is devel-oped for disc cutters’ movement after the research on the rock breaking of forward-slanting disc cutters. Equations of its displacement are established based on the analysis of velocity vector of a disc cutter’s rock-breaking point. The functional relations then are brought forward between the displacement parameters of a rock-breaking point and its coordinate through the analysis of micro displacement of a rock-breaking point. Thus, the geometric equations of rock deformation are derived for the forward-slanting installation of disc cutters. With a linear relationship remaining between the acting force and its deformation either before or after the leap breaking, the constitutive relation of rock deformation can be expressed in the form of generalized Hooke law, hence the comparative analysis of the variation in the resistance of rock to the disc cutters mounted in the forward-slanting way with that in the traditional way. It is discovered that with the same penetration, strain of the rock in contact with forward-slanting disc cutters is apparently on the decline, in other words, the resistance of rock to disc cutters is reduced. Thus wear of disc cutters resulted from friction is lowered and energy consumption is correspondingly decreased. It will be useful for the development of installation and design theory of disc cutters, and significant for the breakthrough in the design of full face rock tunnel boring machine.

  19. Modal and harmonic response analysis of cutter head of juice extractor

    Science.gov (United States)

    Li, Jinkuan; Liu, Zaixin; Zhou, Dingli; Li, Zhao

    2017-01-01

    A cutter head is one of the most important parts in juice extractor, because whether the juice extractor is reliable or secure enough is directly to the cutter head natural frequency as well as its mode shape size. Cutter head is took as an example in this paper. By establishing the vibration dynamics equations and using finite element method, the 6 modal of the cutter head is analyzed. The range of the rotate speed to keep safety is obtained when it is working. The result shows that the highest rotate speed of the cutter head is far lower than its first order critical speed which avoids the sympathetic vibration efficiently, and the cutter head is designed relatively rational. The harmonic response of the cutter head is analyzed based on the result of modal analysis. The resonant frequency and amplitude of cutter head are obtained. They can provide a theoretical basis for the further design optimization of the cutter head.

  20. Optimization Design and Finite Element Analysis of Core Cutter

    Institute of Scientific and Technical Information of China (English)

    CAO Pin-lu; YIN Kun; PENG Jian-ming; LIU Jian-lin

    2007-01-01

    The hydro-hammer sampler is a new type of sampler compared with traditional ones. An important part of this new offshore sampler is that the structure of the core cutter has a significant effect on penetration and core recovery. In our experiments, a commercial finite element code with a capability of simulating large-strain frictional contact between two or more solid bodies is used to simulate the core cutter-soil interaction. The effects of the cutting edge shape, the diameter and the edge angle on penetration are analyzed by non-liner transient dynamic analysis using a finite element method (FEM). Simulation results show that the cutter shape clearly has an effect on the penetration and core recovery. In addition, the penetration of the sampler increases with an increase in the inside diameter of the cutter, but decreases with an increase in the cutting angle. Based on these analyses, an optimum structure of the core cutter is designed and tested in the north margin of the Dalian gulf. Experiment results show that the penetration rate is about 16.5 m/h in silty clay and 15.4 m/h in cohesive clay, while the recovery is 68% and 83.3% respectively.

  1. Dimensions of cookie-cutter-like sets

    Institute of Scientific and Technical Information of China (English)

    MA; Jihua(

    2001-01-01

    [1]Bedford, T., Application of dynamical systems theory to fractals——a study of cookie-cutter sets, in Fractal G eometry and Analysis (eds. Bélair, J., Dubuc, S.), Amsterdam: Kluwer, 1991, 1-44.[2]Falconer, K. J., Techniques in Fractal Geometry, New York: John Wiley & Sons, 1997.[3]Takens, F., Hyperbolicity and Sensitive Chaotic Dynamics at Holmoclinic Bifurcations, Cambridge: Cambridge University Press, 1990, 53.[4]Falconer, K. J., Fractal Geometry-Mathematical Foundations and Application, New York: John Wiley & Sons, 1990.[5]Mattila, P. , Geometry of Sets and Measures in Euclidean Spaces, Cambridge: Cambridge University Press, 1995.[6]Hua Su, Dimensions for generalized self-similar sets, Acta. Math. Appl. Siniea, 1994, 17(4): 551.[7]Feng Dejun, Wen Zhiying, Wu Jun, Some dimensional results for homogeneous Moran sets, Science in China, Ser. A, 1997,40(5): 475.[8]Hua Su, Rao Hui, Wen Zhiying, et al. , On the structures and dimensions of Moran sets, Science in China, Ser. A, 2000,43(8): 836.[9]Tricot, C., Two definitions of fractal dimensions, Math. Proc. Camb. Phil. Soc., 1982, 91(1): 57.[10]Oxtoby, J., Measure and Category, Berlin: Springer-Verlag, 1980.[11]Feng Dejun, Hua Su, Wen Zhiying, Some relations between pre-packing measure and packing measure, Bull. London. Math.Soc., 1999, 31: 665.

  2. Extension of the Vane Pump-Grinder Technology to Manufacture Finely Dispersed Meat Batters.

    Science.gov (United States)

    Irmscher, Stefan B; Gibis, Monika; Herrmann, Kurt; Oechsle, Anja Maria; Kohlus, Reinhard; Weiss, Jochen

    2016-03-01

    A vane pump-grinder system was extended to enable the manufacture of finely dispersed emulsion-type sausages by constructing and attaching a high-shear homogenizer at the outlet. We hypothesized that the dispersing capabilities of the extended system may be improved to the point of facilitating meat-fat emulsification due to an overall increased volumetric energy input EV . Coarsely ground raw material mixtures were processed to yield meat batters at varying volume flow rates (10 to 60 L/min) and rotational rotor speeds of the homogenizer nrotor (1000 to 3400 rpm). The normalized torques acting on pump, grinder, and homogenizer motors were recorded and unit power consumptions were calculated. The structure of the manufactured meat batters and sausages were analyzed via image analysis. Key physicochemical properties of unheated and heated batters, that is, texture, water-binding, color, and solubilized protein were determined. The mean diameter d10 of the visible lean meat particles varied between 352 and 406 μm whereas the mean volume-surface diameter d32 varied between 603 and 796 μm. The lightness L* ranged from 66.2 to 70.7 and correlated with the volumetric energy input and product structure. By contrast, varying process parameters did not impact color values a* (approximately 11) and b* (approximately 8). Interestingly, water-binding and protein solubilization were not affected. An exponential process-structure relationship was identified allowing manufacturers to predict product properties as a function of applied process parameters. Raw material mixtures can be continuously comminuted, emulsified, and subsequently filled into casings using an extended vane pump-grinder.

  3. Thrust and Torque Characteristics Based on a New cutter-head Load Model

    Institute of Scientific and Technical Information of China (English)

    LIU Jianqin; REN Jiabao; GUO Wei

    2015-01-01

    Full face rock tunnel boring machine(TBM) has been widely used in hard rock tunnels, however, there are few published theory about cutter-head design, and the design criteria of cutter-head under complex geological is not clear yet. To deal with the complex relationship among geological parameters, cutter parameters, and operating parameters during tunneling processes, a cutter-head load model is established by using CSM(Colorado school of mines) prediction model. Force distribution on cutter-head under a certain geology is calculated with the new established load model, and result shows that inner cutters bear more force than outer cutters, combining with disc cutters abrasion; a general principle of disc cutters’ layout design is proposed. Within the model, the relationship among rock uniaxial compressive strength(UCS), penetration and thrust on cutter-head are analyzed, and the results shows that with increasing penetration, cutter thrust increases, but the growth rate slows and higher penetration makes lower special energy(SE). Finally, a fitting mathematical model of ZT(ratio of cutter-head torque and thrust) and penetration is established, and verified by TB880E, which can be used to direct how to set thrust and torque on cutter-head. When penetration is small, the cutter-head thrust is the main limiting factor in tunneling;when the penetration is large, cutter-head torque is the major limiting factor in tunneling. Based on the new cutter-head load model, thrust and torque characteristics of TBM further are researched and a new way for cutter-head layout design and TBM tunneling operations is proposed.

  4. Multi-degree-of-freedom coupling dynamic characteristic of TBM disc cutter under shock excitation

    Institute of Scientific and Technical Information of China (English)

    霍军周; 孙晓龙; 李广庆; 李涛; 孙伟

    2015-01-01

    When the tunneling boring machine (TBM) cutterhead tunnels, the excessive vibration and damage are a severe engineering problem, thereby the anti-vibration design is a key technology in the disc cutter system. The structure of disc cutter contains many joint interfaces among cutter ring, cutter body, bearings and cutter shaft. On account of the coupling for dynamic contact and the transfer path among joint interface, mechanical behavior of disc cutter becomes extremely complex under the impact of heavy-duty, which puts forward higher requirements for disc cutter design. A multi-degree-of-freedom coupling dynamic model, which contains a cutter ring, a cutter body, two bearings and cutter shaft, is established, considering the external stochastic excitations, bearing nonlinear contact force, multidirectional mutual coupling vibration, etc. Based on the parameters of an actual project and the strong impact external excitations, the modal properties and dynamic responses are analyzed, as well as the cutter shaft and bearings’ loads and load transmission law are obtained. Numerical results indicate the maximum radial and axial cutter ring amplitudes of dynamic responses are 0.568 mm and 0.112 mm;the maximum radial and axial vibration velocities are 41.1 mm/s and 38.9 mm/s;the maximum radial and axial vibration accelerations are 94.7 m/s2 and 58.6 m/s2;the maximum swing angle and angular velocity of cutter ring are 0.007° and 0.0074 rad/s, respectively. Finally, the maximum load of bearing roller is 40.3 kN. The proposed research lays a foundation for structure optimization design of disc cutter and cutter base, as well as model selection, modification and fatigue life of the cutter bearing.

  5. Apparatus for fixation of grinder shells upon a vibration-grinding casing

    Energy Technology Data Exchange (ETDEWEB)

    Pogosov, Yu.A.; Pugachev, V.S.

    1981-01-01

    A device is proposed for the fixation of grinder shells upon a vibration grinding table. This apparatus utilizes a table-mounting consisting of a shaft with a threaded head for a nut and lock-washer which is located in a mobile position below the locknut. Servicability is improved by utilizing radial-cantilevered protrusions in the mounting to facilitate end contact and fixation to the casing. The bushings and shaft are connected by pairs of threaded nuts while the bushings are spring-loaded relative to the table.

  6. Superhard nanophase cutter materials for rock drilling applications

    Energy Technology Data Exchange (ETDEWEB)

    Voronov, O.; Tompa, G.; Sadangi, R.; Kear, B.; Wilson, C.; Yan, P.

    2000-06-23

    The Low Pressure-High Temperature (LPHT) System has been developed for sintering of nanophase cutter and anvil materials. Microstructured and nanostructured cutters were sintered and studied for rock drilling applications. The WC/Co anvils were sintered and used for development of High Pressure-High Temperature (HPHT) Systems. Binderless diamond and superhard nanophase cutter materials were manufactured with help of HPHT Systems. The diamond materials were studied for rock machining and drilling applications. Binderless Polycrystalline Diamonds (BPCD) have high thermal stability and can be used in geothermal drilling of hard rock formations. Nanophase Polycrystalline Diamonds (NPCD) are under study in precision machining of optical lenses. Triphasic Diamond/Carbide/Metal Composites (TDCC) will be commercialized in drilling and machining applications.

  7. 21 CFR 884.4150 - Bipolar endoscopic coagulator-cutter and accessories.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Bipolar endoscopic coagulator-cutter and... Gynecological Surgical Devices § 884.4150 Bipolar endoscopic coagulator-cutter and accessories. (a) Identification. A bipolar endoscopic coagulator-cutter is a device used to perform female sterilization and...

  8. Cavitation and pressure pulsation characteristics of a non-jamed submerged grinder pump%无阻塞潜水磨碎泵的空化及压力脉动特性研究

    Institute of Scientific and Technical Information of China (English)

    付强; 卢永刚; 朱荣生; 王秀礼; 王学吉

    2016-01-01

    In the actual operation,jam of a submerged grinder pump’s cutter channel is easy to occur.Here,the effects of the grinding pump’s static cutter channel congestion on the pump performance were simulated.The simulation based on the software ANSYS-CFX1 4.0 was condicted to do steady and unsteady calculations for the model of a non-jamed submerged grinder pump and the outside characteristics of the pump were verified with tests.1 /4,1 /3 and 1 /2 channels of the static cutter of the pump were padded,respectively.The analysis results for different channel blockage conditions showed that with increase in level of runner blockage,the pump lift head overall drops,the power declines,the efficiency reduceds,and the maximum efficiency point moves to the small flow field;when 1 /4 and 1 /3 channels of the static cutter grinding runner are padded,there is little effect on the pump lift head,efficiency and power but when 1 /2 channel is padded,the pump lift head and efficiency decrease significantly;with increase in level of runner blockage,the cavitation close to cutters is intensified and becomes more serious,the cavitation at the back of impeller inlet also becomes more serious;with increase in flow,the monitored point’s pressure pulsation on the knife disk reduces,the monitored point’s pressure pulsation on static cutter increases,the pulsating energy of pressure pulsation in the static blade channel is the largest,and the pulsating energy far from the static cutter runner reduces.%由于磨碎泵在实际运行中刀盘的流道容易发生堵塞,本文主要模拟磨碎泵静刀盘的刀盘流道堵塞情况对磨碎泵性能的影响,该模拟基于ANSYS-CFX14.0软件分别对无阻塞潜水磨碎泵模型进行定常和非定常计算,并对无阻塞潜水磨碎泵的外特性进行了试验验证。分别堵塞磨碎泵静刀盘流道的1/4、1/3、1/2,通过对不同的流道堵塞工况分析发现:随着流道堵塞程度

  9. 3000m3/h cutter-suction dredge

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    @@ In October 2004, the Fumin 9 3000 m3/h cutter-suction dredge co-designed by the Dutch IHC and Guangzhou Wenchong Shipyard went through a dock usability test and a 25 meter clean water test. The dredge is the largest of its kind in China, and the most advanced and most efficient cutter-suction dredge in the world. The IHC was responsible for the design of the ship till its working design was taken over by Guangzhou Wenchong Shipyard, the builder of the dredge, who had started its construction on October 23, 2003.

  10. Results of comparative evaluations of cutters used on the KHS-2 coal plow

    Energy Technology Data Exchange (ETDEWEB)

    Krauze, K.; Podsiadlo, A.; Ptak, J. (Akademia Gorniczo-Hutnicza, Cracow (Poland). Instytut Maszyn Gorniczych, Przerobczych i Automatyki)

    1990-01-01

    Reports on investigations of cutters supplied by the firm Halbach-Braun and modernized cutters produced at the Drilling and Mining Machinery Factory Glinik for the KHS-2 coal plow. The investigations were conducted at the Brzeszcze black coal mine. Graphs of cutting force and energy are shown. Results of laboratory and in-situ tests showed that the modernized cutters are about 30% more durable and about 25% more efficient than the Halbach-Braun cutters. Production of the modernized cutters at the Glinik works has allowed imports to be reduced. 2 refs.

  11. Cutting edge curve models for equal pitch cutters and their applications

    Institute of Scientific and Technical Information of China (English)

    吕广明; 王洪滨; 唐余勇; 彭龙刚

    2004-01-01

    A mathematic model is established using infinitesimal geometry for the cutting edge design of special milling cutters which use equal lead helix as cutting edges; equations are given for front-end and proclitic surface of revolution of ball pillar milling cutters, ball taper milling cutters and angularly conical milling cutters;and corresponding models are established for the continuity cutting edge curves of milling cutters. Typical examples are given to illustrate the applications of mathematic models, which prove the correctness and applicability of these geometric models.

  12. Numerical Control System for Virtual Axis Tool Grinders and Conventional Tool Grinders%可用于虚轴和普通刀具刃磨机床的数控系统

    Institute of Scientific and Technical Information of China (English)

    陈友东; 陈五一; 樊锐; 陈鼎昌

    2001-01-01

    A PC-based open computer numerical control system is described. This system can be used both for virtual axis tool grinders and for conventional tool grinders. The hardware setup and software structure are presented. The machine controller consists of two major elements: a PC and an IN/OUT board (installed inside the PC). The software mainly includes movement function lib and user application, which can be reusable. Movement variables are calculated and the resultant data for the axis movement are temporarily stored in the hard disk. The data are then sent to generate real time signals to drive the motors. Examples are detailed to show the grinding control of twist drill points on both a virtual axis tool grinder and a conventional tool grinder.%介绍了一种开放式数控系统.该系统可用在虚轴刀具刃磨机床和普通刀具刃磨机床.给出了该控制系统的硬件和软件结构,并给出了实例:在虚轴刀具刃磨机和普通刀具刃磨机磨出螺旋面钻头的实例.

  13. Voluntary Genital Ablations: Contrasting the Cutters and Their Clients

    Directory of Open Access Journals (Sweden)

    Robyn A. Jackowich, BA

    2014-08-01

    Conclusions: This study may help identify individuals who are at risk of performing illegal castrations. That information may help healthcare providers protect individuals with extreme castration ideations from injuring themselves or others. Jackowich RA, Vale R, Vale K, Wassersug RJ, and Johnson TW. Voluntary genital ablations: Contrasting the cutters and their clients. Sex Med 2014;2:121–132.

  14. 40 CFR 1065.365 - Nonmethane cutter penetration fractions.

    Science.gov (United States)

    2010-07-01

    ... fractions. 1065.365 Section 1065.365 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... Measurements § 1065.365 Nonmethane cutter penetration fractions. (a) Scope and frequency. If you use a FID... penetration fractions of methane, PFCH4, and ethane, PF C2H6. As detailed in this section, these...

  15. The Laser Cutter: A Terrific Addition to Your Tech Program

    Science.gov (United States)

    Buxton, Richard

    2007-01-01

    A laser cutter has found a very welcome home in the technology program at Thomas Jefferson High School for Science and Technology. It has proven an easy-to-use major addition. Lasers come in different types, sizes and power ratings, which means several things must be taken into consideration when selecting the right one for the technology program.…

  16. NEW HIGH STRENGTH AND FASTER DRILLING TSP DIAMOND CUTTERS

    Energy Technology Data Exchange (ETDEWEB)

    Robert Radtke

    2006-01-31

    The manufacture of thermally stable diamond (TSP) cutters for drill bits used in petroleum drilling requires the brazing of two dissimilar materials--TSP diamond and tungsten carbide. The ENDURUS{trademark} thermally stable diamond cutter developed by Technology International, Inc. exhibits (1) high attachment (shear) strength, exceeding 345 MPa (50,000 psi), (2) TSP diamond impact strength increased by 36%, (3) prevents TSP fracture when drilling hard rock, and (4) maintains a sharp edge when drilling hard and abrasive rock. A novel microwave brazing (MWB) method for joining dissimilar materials has been developed. A conventional braze filler metal is combined with microwave heating which minimizes thermal residual stress between materials with dissimilar coefficients of thermal expansion. The process results in preferential heating of the lower thermal expansion diamond material, thus providing the ability to match the thermal expansion of the dissimilar material pair. Methods for brazing with both conventional and exothermic braze filler metals have been developed. Finite element modeling (FEM) assisted in the fabrication of TSP cutters controllable thermal residual stress and high shear attachment strength. Further, a unique cutter design for absorbing shock, the densification of otherwise porous TSP diamond for increased mechanical strength, and diamond ion implantation for increased diamond fracture resistance resulted in successful drill bit tests.

  17. 风引出料一体化粉碎机的设计%Design of Integration Grinder with Air-induced Discharging Device

    Institute of Scientific and Technical Information of China (English)

    王明友; 宋卫东; 李尚昆; 吴金姬; 王教领

    2016-01-01

    To meet the large-scale smashing production of soft straw and hard straw with high fiber materials and overcome the shortcomings of single-mission cutter and shredder, a straw grinder with air-induced discharging device was developed, which realized the force feeding of hard straws with high fiber. The results showed that soft straw could be directly fed into the smashing device without cutting with the average efficiency of 1.27 kg/h and electricity consumption o per ton of 32.0 kW·h. The hard straw with high fiber should be first fed into the shredding device with force feeding rol to cut and then grinded, for which the efficiency average was 0.67 kg/h and electricity consumption per ton was 60.5 kW·h. The machine was stable, safe and reliable with strong adaptability of materials and no-dust operating environ-ment, which satisfied the design requirements.%为满足软质秸秆和硬质高纤维物料规模化粉碎的生产需要,并克服单一切碎机、粉碎机的缺点,设计了一种带风引出料装置的切粉一体化组合式秸秆粉碎机,实现了硬质高纤维秸秆的强制喂入。结果表明,软质秸秆可直接通过粉碎装置喂料口喂入,无需切碎,平均生产率为1.27 kg/h,吨料电耗为32.0 kW·h;硬质高纤维秸秆需通过带有强制喂料辊的切碎装置后进行先切后粉,平均生产率为0.67 kg·h,吨料电耗为60.5 kW·h。该机器具有性能稳定、安全可靠、物料适应性强和操作环境无粉尘等优点,性能满足设计要求。

  18. 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...

  19. The jaw of the worm: GTPase-activating protein EAT-17 regulates grinder formation in Caenorhabditis elegans.

    Science.gov (United States)

    Straud, Sarah; Lee, Inhwan; Song, Bomi; Avery, Leon; You, Young-Jai

    2013-09-01

    Constitutive transport of cellular materials is essential for cell survival. Although multiple small GTPase Rab proteins are required for the process, few regulators of Rabs are known. Here we report that EAT-17, a novel GTPase-activating protein (GAP), regulates RAB-6.2 function in grinder formation in Caenorhabditis elegans. We identified EAT-17 as a novel RabGAP that interacts with RAB-6.2, a protein that presumably regulates vesicle trafficking between Golgi, the endoplasmic reticulum, and plasma membrane to form a functional grinder. EAT-17 has a canonical GAP domain that is critical for its function. RNA interference against 25 confirmed and/or predicted RABs in C. elegans shows that RNAi against rab-6.2 produces a phenotype identical to eat-17. A directed yeast two-hybrid screen using EAT-17 as bait and each of the 25 RAB proteins as prey identifies RAB-6.2 as the interacting partner of EAT-17, confirming that RAB-6.2 is a specific substrate of EAT-17. Additionally, deletion mutants of rab-6.2 show grinder defects identical to those of eat-17 loss-of-function mutants, and both RAB-6.2 and EAT-17 are expressed in the terminal bulb of the pharynx where the grinder is located. Collectively, these results suggest that EAT-17 is a specific GTPase-activating protein for RAB-6.2. Based on the conserved function of Rab6 in vesicular transport, we propose that EAT-17 regulates the turnover rate of RAB-6.2 activity in cargo trafficking for grinder formation.

  20. Optimization of ultrasonic cell grinder extraction of anthocyanins from blueberry using response surface methodology.

    Science.gov (United States)

    Jiang, Hai-Long; Yang, Jun-Li; Shi, Yan-Ping

    2017-01-01

    Ultrasonic cell grinder extraction (UCGE), using water as the solvent, was firstly applied to extract anthocyanins from blueberry. Extraction yield was related with four variables, including ratio of solution to solid, extraction power, buffer time, and extraction time. On the basis of response surface methodology (RSM), the optimal conditions were determined to be the ratio of solution to solid as 25:1(mL/g), the extraction power as 1500W, the buffer time as 3.0s, and the extraction time as 40min. The experimental yield of anthocyanins using UCGE was 2.89mg/g higher than that of conventional ultrasound-assisted extraction (CUAE). This study indicated that UCGE was an innovative, efficient, and environment friendly method in ultrasonic extraction fields, and had a potential to effectively extract other bioactive constituents.

  1. Prudent sperm use by leaf-cutter ant queens

    DEFF Research Database (Denmark)

    Den Boer, Susanne Petronella A; Baer, Boris; Dreier, Stéphanie Agnès Jeanine

    2009-01-01

    glandular secretions or deteriorating sperm-storage organs. We evaluate our findings with a heuristic model, which suggests that the average queen has sperm for almost 9 years of normal colony development. We discuss the extent to which leaf-cutter ant queens have been able to optimize their sperm...... expenditure and infer that our observed averages of sperm number, sperm robustness and sperm use are consistent with sperm depletion being a significant cause of mortality of mature colonies of Atta leaf-cutter ants.......In many species, females store sperm between copulation and egg fertilization, but the consequences of sperm storage and patterns of sperm use for female life history and reproductive success have not been investigated in great detail. In hymenopteran insect societies (ants, bees, wasps...

  2. Pill organizers and pill cutters: risks and limitations.

    Science.gov (United States)

    Borja-Oliveira, Caroline Ribeiro de

    2013-02-01

    In this essay, based on documental analysis, the limitations associated with the use of pill organizers and cutters are discussed and analyzed as a matter of public health. The use of the organizers for storing and carrying tablets and capsules exposes these medications to environmental factors from which their original packaging protected them, compromising their stability and safeness. Cutters also pose the additional risk of causing loss of efficacy, adverse reactions and overdose. On the other hand, the user carrying their own medication reflects the balance between autonomy and self-care, and splitting is sometimes required to comply with certain regimens. It can be concluded that healthcare professionals should observe and guide patients and caregivers in order to avoid risks.

  3. Low-cost silicon wafer dicing using a craft cutter

    KAUST Repository

    Fan, Yiqiang

    2014-05-20

    This paper reports a low-cost silicon wafer dicing technique using a commercial craft cutter. The 4-inch silicon wafers were scribed using a crafter cutter with a mounted diamond blade. The pre-programmed automated process can reach a minimum die feature of 3 mm by 3 mm. We performed this scribing process on the top polished surface of a silicon wafer; we also created a scribing method for the back-unpolished surface in order to protect the structures on the wafer during scribing. Compared with other wafer dicing methods, our proposed dicing technique is extremely low cost (lower than $1,000), and suitable for silicon wafer dicing in microelectromechanical or microfluidic fields, which usually have a relatively large die dimension. The proposed dicing technique is also usable for dicing multiple project wafers, a process where dies of different dimensions are diced on the same wafer.

  4. Development of the MC3133 reefing line cutter

    Energy Technology Data Exchange (ETDEWEB)

    Craig, J.R.

    1977-09-01

    A pyrotechnic actuated reefing line cutter has been developed which, in response to an incoming programmable time delayed electrical firing signal, severs a nylon or Kevlar parachute reefing line following parachute deployment. The design objectives and final design concept which evolved are described. First order approximations and parameter studies leading to a preprototype design are presented. Significant evaluation studies that resulted in the selection of boron/calcium chromate for the initiating charge and titanium subhydride/potassium perchlorate for the output charge are discussed in detail. Final design verification testing data show that the reefing line cutter will meet functional requirements after the following sequential environments: thermal shock, --54/sup 0/C to 90/sup 0/C; mechanical shock, 9806 m/s/sup 2/, 2 ms duration; vibration, 98 m/s/sup 2/, 26-2000 Hz; and linear acceleration, 1960 m/s/sup 2/ for two minutes.

  5. Coast Guard Cutter Procurement: Background and Issues for Congress

    Science.gov (United States)

    2015-07-28

    largest and most technologically sophisticated in the Coast Guard. Each NSC is capable of operating in the most demanding open ocean environments...Analysis Phase 1, Executive Summary, Table ES-11 on page ES-19, and Table ES-10 on page ES-18. The life-cycle O&S cost was calculated through 2050 ...when the seawater temperature was greater than 77 degrees. Cold climate issues include the National Security Cutter not having heaters to keep oil and

  6. Mathematical Modelling of Involute Spur Gears Manufactured by Rack Cutter

    Directory of Open Access Journals (Sweden)

    Tufan Gürkan YILMAZ

    2016-05-01

    Full Text Available In this study, mathematical modelling of asymmetric involute spur gears was situated in by Litvin approach. In this context, firstly, mathematical expressions of rack cutter which manufacture asymmetric involute spur gear, then mathematical expression of asymmetric involute spur gear were obtained by using differential geometry, coordinate transformation and gear theory. Mathematical expressions were modelled in MATLAB and output files including points of involute spur gear’s teeth were designed automatically thanks to macros.

  7. Design of Formed Milling Cutter for Double-Helix Screw Based on Noninstantaneous Envelope Method

    Directory of Open Access Journals (Sweden)

    Yun Li

    2013-01-01

    Full Text Available The design theory and method of formed milling cutter for double-helix screw of progressing cavity pump are presented. Through analyzing the shape and characteristic parameters of double-helix screw, the helicoids equation and axial curve equation of double-helix screw were established. According to the relative position relations between formed milling cutter and double-helix screw in the machining process, the geometric mapping relationship of screw coordinate system and formed milling cutter coordinate system was established by using the coordinate transformation theory. Based on noninstantaneous envelope method and the meshing conditions between formed milling cutter and double-helix screw, the contact line equations were established by minimum value method. By analyzing the machining errors caused by resharpening the formed milling cutter, the tooth back curve equation was established based on spiral of Archimedes, and the profile equation of formed milling cutter with constant back angle was got. On this basis, the formed milling cutter of processing double-helix screw was designed, and the cutter head and tool post were manufactured, respectively. The measuring results have shown that this method can satisfy the requirements of machining accuracy for double-helix screw. So this is an effective method to get formed milling cutter profile for double-helix screw.

  8. Penetration and impact resistance of PDC cutters inclined at different attack angles

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    In order to develop a rotary-percussive bit with diamond-enhanced cutters assisted by high pressure water jets,it is necessary to study the damage mechanism and the penetration properties of PDC cutters subject to different impactload level and rock types. Therefore the impact experiments of the single PDC cutters with different attack angles in fourrocks: black basalt, Missouri red granite, Halston limestone, and a very soft (Roubidoux) sandstone were carried out,and the effects of rake angles of PDC cutters on both the penetration and impact resistance of PDC cutters have been discussed in detail. Test results show that a PDC insert can withstand a very strong impact in compression but is easily damaged by impact shearing, the PDC cutters are more easily damaged by shearing if the attack angles are relatively small, the45 PDC cutters have the least penetration resistance among the cutters tested. Thus it is suggested that the attack anglesof PDC cutters should be larger than 30 for bits which must withstand impact from a hammer

  9. Mathematical simulation of a profile cutter as a surface of revolution

    Science.gov (United States)

    Bubenchikov, A. M.; Kazakavitschyus, S. M.; Shcherbakov, N. R.

    2016-04-01

    Various types of cutters (spherical, toroidal, etc.) are used in surface processing of parts of a transmission mechanism. The cost of a special profile tool is somewhat higher than that of such cutters. But the increase in the cost of the tool is compensated by a significant reduction in the time of processing parts. The present paper deals with a mathematical model of a profile cutter surface (as a surface of revolution) for processing parts of a cylindrical transmission gear with an eccentrically cycloidal gearing (EC-gearing). A computer program for determining radii of the cutter's circular cross sections for a given set of axial displacements was created.

  10. Space cutter compensation method for five-axis nonuniform rational basis spline machining

    Directory of Open Access Journals (Sweden)

    Yanyu Ding

    2015-07-01

    Full Text Available In view of the good machining performance of traditional three-axis nonuniform rational basis spline interpolation and the space cutter compensation issue in multi-axis machining, this article presents a triple nonuniform rational basis spline five-axis interpolation method, which uses three nonuniform rational basis spline curves to describe cutter center location, cutter axis vector, and cutter contact point trajectory, respectively. The relative position of the cutter and workpiece is calculated under the workpiece coordinate system, and the cutter machining trajectory can be described precisely and smoothly using this method. The three nonuniform rational basis spline curves are transformed into a 12-dimentional Bézier curve to carry out discretization during the discrete process. With the cutter contact point trajectory as the precision control condition, the discretization is fast. As for different cutters and corners, the complete description method of space cutter compensation vector is presented in this article. Finally, the five-axis nonuniform rational basis spline machining method is further verified in a two-turntable five-axis machine.

  11. Failure analysis of polycrystalline diamond compact cutters for breaking rock by bending waves theory

    Institute of Scientific and Technical Information of China (English)

    GONG Sheng-wu; ZHAO Fu-jun

    2008-01-01

    The breakage mechanism of the polycrystalline diamond compact(PDC) cutters was analyzed by the energy theory of bending waves. The cutting tests of granite block were conducted on a multifunctional testing device by using the cutter at three kinds of negative fore angles of 30°, 45° and 60°. The results show that, when the edge of the PDC layer is broken, the layer of tungsten cobalt is broken a little under the angle of 30°, while the layer of tungsten cobalt is broken continuously under the angle of60°, their maximum depths are about 2 and 7 mm respectively in the two cases. The eccentric distance mainly depends on the negative fore angle of the cutter. When the cutter thrusts into the rock under an attack angle of 60°, the energy of bending waves reaches the maximum since the eccentric distance is the maximum. So the damage of cutter is the most serious. This test result is consistent with the conclusion of theoretical analysis well. The eccentric distance from the axial line of cutter to the point of action between the rock and cutter has great effect on the breakage of the cutter. Thus during the process of cutting, the eccentric distance should be reduced to improve the service life of PDC cutters.

  12. AN EXPERIMENTAL STUDY ON THE MECHANISMAND PROCESS OF ROCK BREAKAGE WITHTHE PLANETARY CUTTER HEAD

    Institute of Scientific and Technical Information of China (English)

    顾大钊

    1992-01-01

    Based on the kinematic features of the Planetary Cutter Head (PCH),this paper deals with specificity of rock breakago with PCH, and the basic laws of this process are presented, The study shows that the axial force acting on the drilling face by a single cutter and the uniaxial compressive strength of the drilled rock have the marked influence on the penetrating depth of the cutter ,and the breakage of the drilling face with the PCH has two forms,the cyclical and the noncyclical. The major reason why the PCH has higher drilling efficiency than other cutter heads is that the PCH can make more free faces on the drilling face.

  13. Research on Virtual Five-axis CNC Tool Grinder Machining Simulation Technology%五轴数控工具磨床的虚拟加工仿真技术研究

    Institute of Scientific and Technical Information of China (English)

    张哲山; 姚斌; 陆如升; 李飞; 姚博世

    2011-01-01

    The design process of a virtual machining environment for five-axis CNC tool grinder based on the tesearch of the computer aided design and virtual prototype technology has been presented in this paper.This simulation platform is very adapt to the early verification of helical cutter design and manufacturing .And the correctness of NC processing commands can also checkec on this simulation platform.Taking the end mill as an example,the manufacturing process was simulated . The simulation results show that the virtual modeling method is feasible and the result can effectively judge the mutual interference of machine tool system.This method also can imperove the reliability of NC commands.%通过计算机辅助设计与虚拟样机技术,建市了五轴数控工具磨床虚拟加工环境.借助这个平台对回转面刀具进行了设计制造的前期验证,检验加工指令的准确与否.最后以两刃立铣刀为例,利用生成的数控加工程序对其进行了虚拟仿真磨削,结果证明了研究理论的可行性和准确性.同时,加工仿真可有效判断机床工艺系统的相互干涉问题,提高了数控指令的可靠性.

  14. 圆弧头立铣刀端刃CNC磨削仿真技术研究%Research on CNC grinding simulation technology of torus end milling cutter's end edges

    Institute of Scientific and Technical Information of China (English)

    刘建军; 黎荣; 程雪锋; 金晓波; 丁国富

    2012-01-01

    A technology on universal end edges model and CNC grinding simulation of torus end milling cutters is introduced. With the theory of space vector rotation,the universal mathematic model of end edges above center or not was builded. Based on the accurate cutting - edge model, the grinding processes of the end milling cutter end - edge rake & flank faces were researched, and also the wheel' s moving path and tool axis vector were calculated. Meanwhile, the post processing program of five-axis NC grinder and the virtual simulation environment based on VERICUT software were developed, and three kinds of end-edge models with different tooth number were geted through grinding simulation,which validated acquired cutter location data. Taking four edges end milling cutter with two edges above center as example, the grinding simulation technology proposed was verified by measuring the structure parameters of simulation model and physical model,and comparing them with design parameters.%介绍一种圆弧头立铣刀端刃的通用建模及CNC磨削仿真技术.运用空间矢量旋转原理,对过中心和不过中心端齿刃线建立通用数学模型.基于所建立的精确刃线数模,研究了立铣刀端刃前、后刀面的磨削加工工艺并计算出砂轮的运动轨迹和刀轴矢量.开发了五轴数控磨床的后置处理程序和基于VERICUT软件的虚拟仿真环境,加工出三类不同齿数的立铣刀端齿模型,对获得的刀位数据正确性进行了验证.以两齿过中心的四齿平底立铣刀为例,通过测量仿真模型和加工实物的结构参数并与设计参数进行对比,验证了提出的磨削仿真技术的可行性.

  15. 19 CFR 4.1 - Boarding of vessels; cutter and dock passes.

    Science.gov (United States)

    2010-04-01

    ... 19 Customs Duties 1 2010-04-01 2010-04-01 false Boarding of vessels; cutter and dock passes. 4.1... vessels; cutter and dock passes. (a) Every vessel arriving at a Customs port will be subject to such... charge until the vessel has been properly inspected by Customs and brought into the dock or anchorage at...

  16. Stress along main deformation axes in teeth of conical cutters

    Energy Technology Data Exchange (ETDEWEB)

    Ignatov, V.I.; Ignatova, N.I.

    1980-06-01

    Pairs of tension resistors are joined together with mutual axes at an orientation of 90 degrees. These pairs are then placed along the main deformation axis of the cutter tooth at 5 mm intervals and oriented towards each other at 45 degrees. Measurement results are plotted in graphs, which illustrate the fact that bending stresses in teeth along the crown are highly non-uniform, whereby the coefficient of non-uniformity for various phases of tooth engagement varies between 1.3 and 2.2. (3 refs.) (In Russian)

  17. Trajectory Calculator for Finite-Radius Cutter on a Lathe

    Science.gov (United States)

    Savchenkov, Anatoliy; Strekalov, Dmitry; Yu, Nan

    2009-01-01

    A computer program calculates the two-dimensional trajectory (radial vs. axial position) of a finite-radius-of-curvature cutting tool on a lathe so as to cut a workpiece to a piecewise-continuous, analytically defined surface of revolution. (In the original intended application, the tool is a diamond cutter, and the workpiece is made of a crystalline material and is to be formed into an optical resonator disk.) The program also calculates an optimum cutting speed as F/L, where F is a material-dependent empirical factor and L is the effective instantaneous length of the cutting edge.

  18. Cutter Accessibility Map and Its Application for 5-axis Milling Tool-path Generation

    Institute of Scientific and Technical Information of China (English)

    L. L. Li; Y. F. Zhang

    2006-01-01

    In tool-path generation process for 5-axis face milling, the specification of cutter posture is one of the critical issues that contribute to the computation load. In this paper, a quick algorithm is presented to specify the cutter posture at a surface point based on the cutter's accessibility maps (A-maps) at all the sampled points, obtained during cutter selection. Integrated with this quick algorithm, an efficient approach is proposed to generate a set of iso-planar tool-paths for finishing a given surface withmaximum machining efficiency without violating the desirable profile and scallop height tolerance. One example is given to confirm the validity of the quick algorithm for cutter posture and the efficiency of the algorithm for tool-path generation.

  19. Effects of discontinuities on penetration of TBM cutters

    Institute of Scientific and Technical Information of China (English)

    刘杰; 曹平; 杜春黄; 蒋喆; 刘京铄

    2015-01-01

    Based on the triaxial testing machine and discrete element method, the effects of embedded crack on rock fragmentation are investigated in laboratory tests and a series of numerical investigations are conducted on the effects of discontinuities on cutting characteristics and cutting efficiency. In laboratory tests, five propagation patterns of radial cracks are observed. And in the numerical tests, firstly, it is similar to laboratory tests that cracks ahead of cutters mainly initiate from the crushed zone, and some minor cracks will initiate from joints. The cracks initiating from crushed zones will run through the thinner joints while they will be held back by thick joints. Cracks tend to propagate towards the tips of embedded cracks, and minor cracks will initiate from the tips of embedded cracks, which may result in the decrease of specific area, and disturbing layers play as ‘screens’, which will prevent cracks from developing greatly. The peak penetration forces, the consumed energy in the penetration process and the uniaxial compression strength will decrease with the increase of discontinuities. The existence of discontinuities will result in the decrease of the cutting efficiency when the spacing between cutters is 70 mm. Some modifications should be made to improve the efficiency when the rocks containing groups of discontinuities are encountered.

  20. The Design of Form Milling Cutter as the Curve of the Back of Tooth Is Logarithmic Spiral

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Form milling cutter is built-for-purpose cutter which process the form surface, for example, usually process male and female circular arc face and form trench and so on. From the traditional concept, form milling cutter is divided into pointed tooth and relieving follow its structure. Relieving shaped cutter is more convenient than pointed tooth milling cutter, because only its rake face is needed to grind after it turn into blunting, so the current books which are used in college almost select relieving ...

  1. Side force formation mechanism and change law of TBM center cutter

    Institute of Scientific and Technical Information of China (English)

    夏毅敏; 田彦朝; 谭青; 侯禹蒙

    2016-01-01

    The center cutter of a hard rock tunnel boring machine (TBM) is installed on the cutterhead at a small radius and thus bears complex side force. Given this fact, the formation mechanism and change law of the side force suffered by the center cutter were studied. Based on the rock shear failure criterion in combination with the lateral rolling width, a model for predicting the average side force was set up. Besides, a numerical analysis model of the rock fragmentation of the center cutter was established, and the instantaneous load changing features were investigated. Results shows that the inner side of the center cutter can form lateral rolling annulus in rock during the rotary cutting process. The smaller the installation radius is, the greater the cutter side force will be. In a working condition, the side force of the innermost center cutter is 11.66 kN, while it decreases sharply when installation radius increases. Variation tends to be gentle when installation radius is larger than 500 mm, and the side force of the outermost center cutter is reduced to 0.74 kN.

  2. Topological pressure and fractal dimensions of cookie-cutter-like sets

    CERN Document Server

    Roychowdhury, Mrinal Kanti

    2012-01-01

    The cookie-cutter-like set is defined as the limit set of a sequence of classical cookie-cutter mappings. For this cookie-cutter set it is shown that the topological pressure function exists, and that the fractal dimensions such as the Hausdorff dimension, the packing dimension and the box-counting dimension are all equal to the unique zero $h$ of the pressure function. Moreover, we have shown that the $h$-dimensional Hausdorff measure and the $h$-dimensional packing measure are finite and positive.

  3. Comparison of resistance to cutting by selected types of cutters used on shearer loaders

    Energy Technology Data Exchange (ETDEWEB)

    Krauze, K. (Akademia Gorniczo-Hutnicza, Cracow (Poland))

    1990-02-01

    Presents investigation results on resistance to cutting by radial and tangential cutters used with worm-type ripping heads of shearers. A test stand is described where four types of cutters were tested. Cutting depth and pitch were varied during tests within 4-16 mm and 10-25 mm respectively. The results were statistically analyzed and exponential regression equations and confidence intervals obtained are presented. Graphs of specific cutting energy versus cutting depth and of pitch to cutting depth ratio are shown. Cutter types with the best and worst dynamic indices and energy consumption values were determined as a result of the tests conducted. 1 ref.

  4. Analysis and modeling of error of spiral bevel gear grinder based on multi-body system theory

    Institute of Scientific and Technical Information of China (English)

    CHEN Shu-han; YAN Hong-zhi; MING Xing-zu

    2008-01-01

    Six-axis numerical control spiral bevel gear grinder was taken as the object, multi-body system theory and Denavit-Hartenberg homogeneous transformed matrix (HTM) were utilized to establish the grinder synthesis error model, and the validity of model was confirmed by the experiment. Additionally, in grinding wheel tool point coordinate system, the errors of six degrees of freedom were simulated when the grinding wheel revolving around C-axis, moving along X-axis and Y-axis. The influence of these six errors on teeth space, helix angle, pitch, teeth profile was discussed. The simulation results show that the angle error is in the range from -0.1484 rad to -0.2419 rad when grinding wheel moving along X, Y-axis; the translation error is in the range from 0.8660 μm to 3.6053 μm when grinding wheel moving along X-axis. These angle and translation errors have a great influence on the helix angle, pitch, teeth thickness and tooth socket.

  5. MODELING OF RUNNING CUTTERS FOR SHAPING OF IMPROVED NONINVOLUTE TOOTH GEARS

    Directory of Open Access Journals (Sweden)

    Tatyana TRETYAK

    2012-05-01

    Full Text Available The questions of tooling design for production of advanced gears are considered. Engineering is based on the special applied development of the mathematical theory of multiparametric mappings of space. In fulfilled engineering of gear cutting tools for shaping of noninvolute gears it is provided for exclusion of distorted profiling after tool regrinds. There are proposed calculation algorithms, which may be used in dataware of respective CAD/CAM systems of maintenance for tooling backup. Among developed tools there are assembled shaping cutters with prismatic and round cutters. Compensatory possibilities of proposed assembled shaping cutters are ensured by repositioning of shaped cutting edges after their regrindings: by linear displacement of prismatic shaped cutters and angular displacement of round ones respectively.

  6. The vertical shaft construction technology of cutter head transformation of large diameter shield

    Institute of Scientific and Technical Information of China (English)

    He Feng; Wang Ying; Wang Zhenfei; Wang Baiquan

    2012-01-01

    Taking vertical shaft construction of cutter transformation of the Beijing underground diameter shield for ex- ample, the design and construction of cutter structure transformation under complex boundary conditions for large diameter shield were discussed. Practice about how to ensure the structure safety of the shaft as well as well-coordinated shield construction was explored, and reliable solutions were provided successfully, which can provide reference for similar projects.

  7. Study of postures in sugarcane cutters in the Pontal of Paranapanema-SP, Brazil.

    Science.gov (United States)

    de Anchieta Messias, Iracimara; Okuno, Emico

    2012-01-01

    The expansion of sugarcane monoculture in Brazil in the last decades has pointed out to the necessity of considering the question of sugarcane cutters occupational health. In this work we present a cross-sectional study aiming to examine the occupational posture of a group of sugarcane cutters, which work in a cane field located in the region of Pontal do Paranapanema- SP, Brazil. The study was made using the Ergonomic Analysis of Work - EAW methodology and the postural analysis method by Win-OWAS. Through the obtained records of postures, it was observed that during a workday the sugarcane cutters remain standing erect on two legs or in one leg 66% of the time and that their trunk remain tilted and in rotation, according to 63% of the positions categorized. It was also observed that the sugarcane cutter trunk performs repetitive and boundless movements during his routine of work, which can expose this individual to additional wear of their musculoskeletal functions. The activities in which the individual engages have favorable or adverse influence on his posture. The repetitive movements involved in specialized occupations are equivalent to repeated exercises, thus may be responsible for the excessive development of certain muscle groups. The study suggests that the postures adopted by sugarcane cutters can overload their musculoskeletal system and predispose the cutters to work-related musculoskeletal diseases.

  8. Effect of cutter type on sediment pollutants release in channel dredging

    Science.gov (United States)

    Yu, Y. R.; Chen, Y.; Dong, M. M.; Yang, B. L.

    2016-08-01

    Dredging activities are often used to maintain existing navigation channels. However’ traditional dredging equipment inevitably leads to sediment resuspension and nutrient loading in water. In this work’ the existing cutter used for dredging was transformed environmentally to reduce the release amount of sediment pollutants’ and to avoid the formation of secondary pollution to water bodies. Simulated tests with a general cutter’ a spiral cutter’ along with a general and spiral cutter equipped with the anti-diffusion device were conducted respectively in this study. The change of pollutants concentration in overlying water was examined. The environmental performance of each different structure cutter was comparatively analysed as well. The result revealed that in channel dredging with a spiral cutter’ the release amount of sediment pollutants was less than with a general cutter’ and that a general/spiral cutter equipped with the anti-diffusion device could effectively reduce the release amount of sediment contaminants’ particularly the release of the nitrogen nutrient during the 1h after the dredging treatment. The best transformation scheme for a cutter suction dredger (CSD) in its environmental-protection function may be: a spiral cutter equipped with the anti-diffusion device.

  9. Differentiation and analysis on rock breaking characteristics of TBM disc cutter at different rock temperatures

    Institute of Scientific and Technical Information of China (English)

    谭青; 张桂菊; 夏毅敏; 李建芳

    2015-01-01

    In order to study rock breaking characteristics of tunnel boring machine (TBM) disc cutter at different rock temperatures, thermodynamic rock breaking mathematical model of TBM disc cutter was established on the basis of rock temperature change by using particle flow code theory and the influence law of interaction mechanism between disc cutter and rock was also numerically simulated. Furthermore, by using the linear cutting experiment platform, rock breaking process of TBM disc cutter at different rock temperatures was well verified by the experiments. Finally, rock breaking characteristics of TBM disc cutter were differentiated and analyzed from microscale perspective. The results indicate the follows. 1) When rock temperature increases, the mechanical properties of rock such as hardness, and strength, were greatly reduced, simultaneously the microcracks rapidly grow with the cracks number increasing, which leads to rock breaking load decreasing and improves rock breaking efficiency for TBM disc cutter. 2) The higher the rock temperature, the lower the rock internal stress. The stress distribution rules coincide with the Buzin Neske stress circle rules: the maximum stress value is below the cutting edge region and then gradually decreases radiant around; stress distribution is symmetrical and the total stress of rock becomes smaller. 3) The higher the rock temperature is, the more the numbers of micro, tensile and shear cracks produced are by rock as well as the easier the rock intrusion, along with shear failure mode mainly showing. 4) With rock temperature increasing, the resistance intrusive coefficients of rock and intrusion power decrease obviously, so the specific energy consumption that TBM disc cutter achieves leaping broken also decreases subsequently. 5) The acoustic emission frequency remarkably increases along with the temperature increasing, which improves the rock breaking efficiency.

  10. Investigation and improvements of flatbed laser engravers and cutters

    Science.gov (United States)

    Aichinger, J.; Hager, P.; Schuöcker, D.

    2012-07-01

    Besides the industrially widely-used galvanometer scanner for laser marking especially flatbed laser engravers and cutters are well established in graphic and design branches. Compared to the vector based technology of galvo-systems most of the laser engravers are based on pixel data produced out of graphic-or photo-programs and mainly engrave large scale areas such as signboards or printing plates. The human organ of sight is very sensitive to unwanted picture effects or distortions. In order to get rid of such disturbing effects a flat bed laser engraver of a technology leading company has been analyzed to find out these errors, identify possible causes and ways to eliminate them. In addition to this vector image processing and cutting of non metal sheets is also an important feature which could be improved by modifying the motion algorithms. During this investigation the whole laser machine was reduced to a model in MatLab including the laser source, motion system and material data.

  11. Prudent sperm use by leaf-cutter ant queens

    DEFF Research Database (Denmark)

    Den Boer, Susanne Petronella A; Baer, Boris; Dreier, Stéphanie Agnès Jeanine;

    2009-01-01

    In many species, females store sperm between copulation and egg fertilization, but the consequences of sperm storage and patterns of sperm use for female life history and reproductive success have not been investigated in great detail. In hymenopteran insect societies (ants, bees, wasps), reprodu......In many species, females store sperm between copulation and egg fertilization, but the consequences of sperm storage and patterns of sperm use for female life history and reproductive success have not been investigated in great detail. In hymenopteran insect societies (ants, bees, wasps......), reproduction is usually monopolized by one or relatively few queens, who mate only during a brief period early in life and store sperm for later use. The queens of some ants are particularly long-lived and have the potential to produce millions of offspring during their life. To do so, queens store many sperm...... cells, and this sperm must remain viable throughout the years of storage. Queens should also be under strong selection to use stored sperm prudently when fertilizing eggs. We used the leaf-cutter ant Atta colombica to investigate the dynamics of sperm use during egg fertilization. We show that queens...

  12. Design and clinical application of the 'styloidectome' styloid process cutter.

    Science.gov (United States)

    Zhibin, W; Min, J

    2006-09-01

    A styloid process (SP) cutter was developed and put into clinical use. The design of components of the 'styloidectome' was based on the principles of mechanics. The measurements of the individual parts were determined on the basis of morphological data of the oropharynx from 40 subjects undergoing tonsillectomy under general anaesthesia. Experiments showed that the instrument could be used to transect the SP and excise the amputated bones from the deep tissue space. We used the instrument for the resection of elongated SPs, via an oral approach, in seven in-patients (involving 10 SPs) under general anaesthesia and in two out-patients (involving three SPs) under local anaesthesia. The length of the resected SP ranged from 0.8 to 2.5 cm and the stump of the SP was smooth. The removal lasted only seconds and blood loss was minimal, without any complications. The styloidectome was reliable, easy to use and could be used for the resection of an elongated SP under general or local anaesthesia.

  13. Plastibell Device Circumcision versus Bone Cutter Technique in terms of Operative Outcomes and Parent's Satisfaction.

    Science.gov (United States)

    Mehmood, Tahir; Azam, Hammad; Tariq, Muhammad; Iqbal, Zafar; Mehmood, Hassan; Shah, Syed Asif Hussain

    2016-01-01

    To compare the rate of complications of Plastibell and bone cutter circumcision technique and recognition of top worries and satisfaction rate in the mind of parents before and after the procedure of Plastibell device (PD) circumcision in infants less than 6 months of age. It was a descriptive prospective study conducted at department of surgery Sheikh Zayed Hospital, Rahim Yar Khan. Two hundred parents of infants of less than six months of age were recruited for this study. Infants were divided into two equal groups. Group I included Plastibell circumcision technique and Group II included Bone Cutter Circumcision technique. Data was analyzed using SPSS Version 17. Independent sample t-test and chi-square test was used to compare quantitative and qualitative variables respectively. P-value fever (42.0%). Fear of pain and bleeding (66.0%). Plastibell Device method was associated with less operation time and bleeding as compared to bone cutter method (P-value Post-operatively, 98% parents showed complete procedural satisfaction in Plastibell group versus 87% parents in bone cutter one month after surgery (P-value 0.003). About 4% parents in bone cutter method group showed cosmetic displeasure versus only 1% parents in plastibell device group. The study concluded that Plastibell Device circumcision is a safer technique for circumcision and is associated with highest level of parent's satisfaction.

  14. Simulation of rock fragmentation induced by a tunnel boring machine disk cutter

    Directory of Open Access Journals (Sweden)

    Huiyun Li

    2016-05-01

    Full Text Available A constitutive model based on the Johnson–Cook material model and the extended Drucker–Prager strength criterion was implemented in LS-DYNA to simulate the rock failure process induced by a single disk cutter of a tunnel boring machine. The normal, rolling, and side forces were determined by numerical tests. The simulation results showed that the normal and rolling forces increased with increasing penetration while the side force changed little. The normal force also increased under the conditions of confining pressures. The damage region of rock and cutting forces were also obtained by simulation of two disk cutters acting in tandem with different cutting spacings. The optimum ratio of cutter spacing to penetration depth determined from numerical modeling agrees well with that obtained by linear cutting machine tests. The average normal and rolling forces acting on the first cutter are slightly greater than those acting on the second when the cutting disk spacing is relatively small. The numerical modeling was verified to accurately capture the fragmentation of rock induced by disk cutter.

  15. The three-dimension model for the rock-breaking mechanism of disc cutter and analysis of rock-breaking forces

    Institute of Scientific and Technical Information of China (English)

    Zhao-Huang Zhang; Fei Sun

    2012-01-01

    To study the rock deformation with three-dimensional model under rolling forces of disc cutter,by carrying out the circular-grooving test with disc cutter rolling around on the rock,the rock mechanical behavior under rolling disc cutter is studied,the mechanical model of disc cutter rolling around the groove is established,and the theory of single-point and double-angle variables is proposed.Based on this theory,the physics equations and geometric equations of rock mechanical behavior under disc cutters of tunnel boring machine (TBM) are studied,and then the balance equations of interactive forces between disc cutter and rock are established.Accordingly,formulas about normal force,rolling force and side force of a disc cutter are derived,and their validity is studied by tests.Therefore,a new method and theory is proposed to study rock- breaking mechanism of disc cutters.

  16. Fix 40!

    Index Scriptorium Estoniae

    2008-01-01

    Ansambel Fix peab 13. detsembril Tallinnas Saku Suurhallis oma 40. sünnipäeva. Kontserdi erikülaline on ansambel Apelsin, kaastegevad Jassi Zahharov ja HaleBopp Singers. Õhtut juhib Tarmo Leinatamm

  17. Fix 40!

    Index Scriptorium Estoniae

    2008-01-01

    Ansambel Fix peab 13. detsembril Tallinnas Saku Suurhallis oma 40. sünnipäeva. Kontserdi erikülaline on ansambel Apelsin, kaastegevad Jassi Zahharov ja HaleBopp Singers. Õhtut juhib Tarmo Leinatamm

  18. Drum-type steel-ball coal grinders for a direct-injection black-coal-dust combustor. Planning, performance and operation experience at the heating power plant Herne III

    Energy Technology Data Exchange (ETDEWEB)

    Heitmueller, W.; Strauss, K.; Thelen, F.

    1987-01-01

    The authors report on the retrofitting of the combustion system of the 300 MW unit of the Herne heating power plant which was necessitated by the application of large quantities of low-volatile coal. They review the new design concept and its resulting requirements, the switching regime of the grinding and firing system, the design mode of operation, construction and positioning of the drum-type steel-ball coal grinder, and discuss in detail the design configurations of and initial operating results gained with grinder neck, sifter, sifter characteristics, ground materials recirculation, liner of grinding drume, hydrostatic slide bearing, grinder drive and findings for a further development of this type of ball grinder. (HAG).

  19. Metapleural gland secretion of the leaf-cutter ant Acromyrmex octospinosus: New compounds and their functional significance

    DEFF Research Database (Denmark)

    Ortius-Lechner, Diethe; Maile, Roland; Morgan, E. David

    2000-01-01

    formicidae, leaf-cutter ants, Acromyrmex octospinosus, gas chromatography, mass spectrometry, metapleural gland, carboxylic and fatty acids, lactones, keto acids, antibiotics.......formicidae, leaf-cutter ants, Acromyrmex octospinosus, gas chromatography, mass spectrometry, metapleural gland, carboxylic and fatty acids, lactones, keto acids, antibiotics....

  20. Characteristics of Speed Line Cutter and Fringe Analysis of Workpiece Surface

    Directory of Open Access Journals (Sweden)

    Shuai Wang

    2014-02-01

    Full Text Available Easy to operate, speed line cutter has a high machining cost performance, so is very popular among the majority of users. The precision of guide rails, screws and nuts used in most of the machines is not high, and the machine control cannot compensate for the screw pitch error, clearance during the transmission and machining error due to electrode wear. Furthermore, control signal may also be lost in control process. The development of speed line cutter focuses on the quality and machining stability of CNC speed line cutter. This article makes an analysis about the impact of machine’s inherent characteristics on machining workpiece surface, and concludes that analysis shall be made on the irregular fringe, therefore to heighten the machining precision.

  1. Mathematical Modeling on Obligate Mutualism: Interactions between leaf-cutter ants and their fungus garden

    CERN Document Server

    Kang, Yun; Clark, Rebecca; Fewell, Jennifer

    2011-01-01

    We propose a simple mathematical model by applying Michaelis-Menton equations of enzyme kinetics to study the mutualistic interaction between the leaf cutter ant and its fungus garden at the early stage of colony expansion. We derive the sufficient conditions on the extinction and coexistence of these two species. In addition, we give a region of initial condition that leads to the extinction of two species when the model has an interior attractor. Our global analysis indicates that the division of labor by workers ants and initial conditions are two important {factors} that determine whether leaf cutter ants colonies and their fungus garden survive and grow can exist or not. We validate the model by doing the comparing between model simulations and data on fungal and ant colony growth rates under laboratory conditions. We perform sensitive analysis and parameter estimation of the model based on the experimental data to gain more biological insights on the ecological interactions between leaf cutter ants and ...

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

    Science.gov (United States)

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

    2011-05-01

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

  3. Design and Manufacture of the Shaving Cutter with Unequal Depth Gashes

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Gear shaving is a gear finishing operation of high efficiency and high precision. After shaved by shaving cutter of true involute profile, there are the "mid-concave" phenomena around the pitch points of the work gear tooth flanks inevitably. This problem severely affects the shaving accuracy and gear transmission quality, which hasn't been resolved thoroughly for a long time. Aiming at the problem, based on shaving mechanism and the analysis on gear tooth profile mid-concave, a new-style shaving cutter wi...

  4. 手动平面磨床进刀机构改造%Transformation of Tool Feed Unit of Manual Surface Grinder

    Institute of Scientific and Technical Information of China (English)

    高洪浩

    2015-01-01

    This paper introduces the use of hydraulic drive ratchet mechanism as an automatic tool feed unit and application in the reconstruction of Manual surface grinder .%本文介绍了在手动平面磨床改造中使用液压驱动棘轮机构作为自动进刀机构的方案及应用.

  5. Dynamic Characteristics of Transmission System for the Internal Grinder%内圆磨床传动系统的动力特性分析

    Institute of Scientific and Technical Information of China (English)

    伍建国; 孙庆鸿; 毛海军; 郁文凯; 蔡英

    2002-01-01

    基于Riccati传递矩阵法建立了内圆磨床传动系统的动力学模型.由模态柔度和弹性分布率的计算,分析了原内圆磨床传动系统的动态特性,应用动柔度与模态柔度的关系,找出传动系统的危险模态及其该模态上的薄弱环节,提出了结构修改方案,避免了参数调整的盲目性,并预测了其动态性能,在内圆磨床传动系统设计中得到了有效的应用.%The dynamics model of the transmission system of the internal grinder is established on the bases of Riccati transfer matrix. The dynamic characteristics of the internal grinder are obtained by analyzing the relationship between dynamic modal flexibility and modal flexibility, which is used to find out the dangerous model of the transmission system and its weak areas. Then design parameters of weak areas are modified, the new one from the old structure is put forward, and the dynamic characteristics of new structure are forecast through the calculations of the modal flexibility and elasticity distribution rate. This method is applied successfully in designing the transmission system of the internal grinder.

  6. Cut-and-Paste of DNA Using an Artificial Restriction DNA Cutter

    Directory of Open Access Journals (Sweden)

    Makoto Komiyama

    2013-02-01

    Full Text Available DNA manipulations using a completely chemistry-based DNA cutter (ARCUT have been reviewed. This cutter, recently developed by the authors, is composed of Ce(IV/EDTA complex and two strands of pseudo-complementary peptide nucleic acid. The site-selective scission proceeds via hydrolysis of targeted phosphodiester linkages, so that the resultant scission fragments can be easily ligated with other fragments by using DNA ligase. Importantly, scission-site and site-specificity of the cutter are freely tuned in terms of the Watson–Crick rule. Thus, when one should like to manipulate DNA according to the need, he or she does not have to think about (1 whether appropriate “restriction enzyme sites” exist near the manipulation site and (2 whether the site-specificity of the restriction enzymes, if any, are sufficient to cut only the aimed position without chopping the DNA at non-targeted sites. Even the human genome can be manipulated, since ARCUT can cut the genome at only one predetermined site. Furthermore, the cutter is useful to promote homologous recombination in human cells, converting a site to desired sequence. The ARCUT-based DNA manipulation should be promising for versatile applications.

  7. Cutter-workpiece engagement determination for general milling using triangle mesh modeling

    Directory of Open Access Journals (Sweden)

    Xun Gong

    2016-04-01

    Full Text Available Cutter-workpiece engagement (CWE is the instantaneous contact geometry between the cutter and the in-process workpiece during machining. It plays an important role in machining process simulation and directly affects the calculation of the predicted cutting forces and torques. The difficulty and challenge of CWE determination come from the complexity due to the changing geometry of in-process workpiece and the curved tool path of cutter movement, especially for multi-axis milling. This paper presents a new method to determine the CWE for general milling processes. To fulfill the requirement of generality, which means for any cutter type, any in-process workpiece shape, and any tool path even with self-intersections, all the associated geometries are to be modeled as triangle meshes. The involved triangle-to-triangle intersection calculations are carried out by an effective method in order to realize the multiple subtraction Boolean operations between the tool and the workpiece mesh models and to determine the CWE. The presented method has been validated by a series of case studies of increasing machining complexity to demonstrate its applicability to general milling processes.

  8. Structural fatigue life assessment and sustainment implications for a New Class of US Coast Guard Cutters

    NARCIS (Netherlands)

    Stambaugh, K.; Drummen, I.; Cleary, C.; Sheinberg, R.; Kaminski, M.L.

    2014-01-01

    This paper presents an overview of the US Coast Guard’s Fatigue Life Assessment Project (FLAP) and the application of the results in hull structure lifecycle management of the National Security Cutter class. One of the key measurements of the FLAP instrumentation included a radar based wave data

  9. Research on the cutting performance and the wear mechanism of the cermet cutter in high speed turn-milling

    Institute of Scientific and Technical Information of China (English)

    JIA Chun-de; HUANG Shu-tiao; JIANG Zeng-hui; ZHANG Zhi-jun; SHI Li

    2005-01-01

    When machining D60 steel by high speed turn-milling under the different cooling and lubricating conditions, the cutting performance and the wear mechanism of the cermet cutter are researched. With water soluble cooling fluid, the wear performance of the cermet cutter is bad, and does not adapt to the requirements of machining. However, when machining D60 by high speed turn-milling is under dry conditions, the wearing performance of the cermet cutter is very good and the cutting time lasts almost 3 hours. The wear mechanism of the cermet cutter under the water soluble cooling fluid is different from the dry condition. With the water soluble cooling fluid, a great deal of little chap units are formed since high frequency alternates heat stress. The crash and desquamate of these chap units is the main cause of the cutter wearing. Under dry cutting conditions, it is the main cause of cermet cutter wear in the felting phase intenerating causing rigid phase grains to fall.

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

    Directory of Open Access Journals (Sweden)

    Ke Xu

    2017-07-01

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

  11. 四磨头磨簧机模态分析及优化设计%Modal analysis and design optimizationon of spring end grinder with four wheels

    Institute of Scientific and Technical Information of China (English)

    黄金根; 季磊; 郑子军

    2013-01-01

    Aiming at the vibration of spring end grinder process, the finite element numerical simulation analysis method was used to study the dynamic characteristics of the spring end grinder with four wheel. Solidworks 3D software was used to create solid model of spring end grinder,the finite element analysis software ANSYS Workbench was applied to conduct modal analysis of the simplified model, then the inherent vibration mode and natural frequency of the each mode state were obtained. Structural weaknesses of the machine structure of spring end grinder were optimized and improved. The results indicate that the improvement of the dynamic characteristics through the improvement of the bed is conducive to improve the machine's lower order natural frequency. The first order natural frequency of the bed is increased by 57.2%, the first order modal natural frequency of the whole improved machine is increased by 103%, which stays away from the motor vibration frequency to prevent the occurrence of resonance.%针对磨簧机在加工过程中存在的颤动问题,采用有限元数值模拟分析方法,研究了四磨头磨簧机的动态特性.利用Solidworks三维软件对磨簧机进行了实体建模,运用有限元分析软件ANSYS Workbench对简化模型进行了模态分析,得到了各阶模态的固有振型和固有频率,并对磨簧机机床结构的薄弱环节进行了结构上的优化和改进.研究结果表明,通过对床身的改进,其动态特性的改善有利于提高整机的低阶固有频率;床身的第一阶固有频率提高了57.2%,改进后的整机第一阶模态固有频率提高了103%,并且远离电机的激振频率,能够防止加工过程中共振现象的发生.

  12. Protein-energy supplements to preserve nutritional status of sugar cane cutters.

    Science.gov (United States)

    Chiarello, Paula; Sobrinho, Paulo Scatena; Marçal Vieira, Marta Neves Campanelli; Garcia, Rosa Wanda Diez

    2006-12-01

    Sugar cane cutters in south-eastern Brazil are temporarily hired for the harvest period of 8 months. They often have minimal benefits and may not receive adequate nutrition. To evaluate alterations in weight and body composition of sugar cane cutters during harvest with the use of protein-energy and electrolyte supplements. Three products were used daily: a milk drink, a seasoned manioc meal mixture and an electrolyte replacement fluid, adding approximately 398 kcal and 28.5 g of protein/day. There were small, but significant, reductions in body mass index and percentage body fat with maintenance of lean mass. There was a significant improvement in hydration status, serum albumin and cholesterol. There were no medical absences related to dehydration. Even though alterations in body mass and biochemistry were small, the significance of the findings suggests these supplements may have a useful role to play in reducing lean mass losses and maintaining nutritional and hydration status of these workers.

  13. Performance of Rotary Cutter Type Breaking Machine for Breakingand Deshelling Cocoa Roasted Beans

    Directory of Open Access Journals (Sweden)

    Sukrisno Widyotomo

    2005-12-01

    Full Text Available Conversion of cocoa beans to chocolate product is, therefore, one of the promising alternatives to increase the value added of dried cocoa beans. On the other hand, the development of chocolate industry requires an appropriate technology that is not available yet for small or medium scale of business. Breaking and deshelling cocoa roasted beans is one important steps in cocoa processing to ascertain good chocolate quality. The aim of this research is to study performance of rotary cutter type breaking machine for breaking and deshelling cocoa roasted beans. Indonesian Coffee and Cocoa Research Institute has designed and tested a rotary cutter type breaking machine for breaking and deshelling cocoa roasted beans. Breaker unit has rotated by ½ HP power, single phase, 110/220 V and 1440 rpm. Transmission system that use for rotating breaker unit is pulley and single V belt. Centrifugal blower as separator unit between cotyledon and shell has specification 0.5 m 3 /min air flow, 780 Pa, 370 W, and 220 V. Field tests showed that the optimum capacity of the machine was 268 kg/h with 500 rpm speed of rotary cutter, 2,8 m/s separator air flow, and power require was 833 W. Percentage product in outlet 1 and 2 were 94.5% and 5.5%. Particle distribution from outlet 1 was 92% as cotyledon, 8% as shell in cotyledon and on outlet 2 was 97% as shell, 3% as cotyledon in shell. Key words:cocoa, breaking, rotary cutter, quality.

  14. Performance of Rotary Cutter Type Breaking Machine for Breakingand Deshelling Cocoa Roasted Beans

    OpenAIRE

    2005-01-01

    Conversion of cocoa beans to chocolate product is, therefore, one of the promising alternatives to increase the value added of dried cocoa beans. On the other hand, the development of chocolate industry requires an appropriate technology that is not available yet for small or medium scale of business. Breaking and deshelling cocoa roasted beans is one important steps in cocoa processing to ascertain good chocolate quality. The aim of this research is to study performance of rotary cutter type...

  15. Nonlinear mathematical models for simulation modeling of dynamic processes in feed systems of cutter loaders

    Energy Technology Data Exchange (ETDEWEB)

    Gorbatov, P.A.; Plyungin, A.V. (Donetskii Politekhnicheskii Institut (USSR))

    1990-12-01

    Presents calculation methods and mathematical models of dynamic processes that occur in feed systems of cutter loaders with rigid pulling elements. Characteristics of dynamic interactions between driving wheels and the working section of the pulling system are taken into account. Mathematical models are given that describe the dynamic operation of the feed system. A method for calculation of a hydraulic vibration compensating system and its mathematical model is presented. Effectiveness of the vibration compensating system is discussed. 2 refs.

  16. Bionic cutter of cutter suction dredger with ant colony optimization%绞吸式挖泥船仿生绞刀刀齿的蚁群优化

    Institute of Scientific and Technical Information of China (English)

    穆乃超; 许焕敏; 邬同舟

    2014-01-01

    为了提高绞吸式挖泥船仿生绞刀减粘降阻的效果,获得更高的生产效率和经济效益,应用蚁群算法对仿生绞刀的凸包的几何尺寸及其分布进行优化,得到对于不同类型的土壤和在一定的压力范围内所需的凸包形仿生绞刀的结构尺寸。%In order to reduce the adhesion and friction of soil, the effect of the adhesion and resistance, and gain higher productivity and economic efficiency. The application of ant colony algorithm for bionic cutter geometry and distribution of the convex hull is optimized to obtain the desired convex hull-shaped cutter biomimetic structure within different types of soil and a certain pressure range.

  17. Operation of milling-cutter crushers in the Sukhodol'sk coal preparation plant

    Energy Technology Data Exchange (ETDEWEB)

    Lesikov, A.V.

    1984-04-01

    The Sukhodol'sk coal preparation plant, constructed in 1962 in the Donbass, and with a capacity 4,900 t/d, is equipped with 2 railroad car tippler systems. Coal is supplied in MPS cars. In winter, coal fines supplied to the plant freeze and form large blocks which do not pass through screens separating tipplers from coal hoppers. Breaking up coal blocks is time consuming. From 6 to 18 workers cut coal each day in winter. The Voroshilovgradugleobogashchenie developed the DFM-2 milling cutter for breaking up coal blocks in 1980. In 1982 the system was modified. The cutting drum which consists of 23 discs has a diameter of 750 mm and is 3850 mm wide, revolution rate is 245 rpm. The system is driven by AO2-92-6 and AO2-52-6 electric motors with a rated power of 7.5 kW. The complete milling cutter system consists of 2 units of DFM-2 cutters. The DFM-2 weighs 10.64 t, is 2.3 m long, 3.83 m wide and 1.28 m high. Cutting frozen coal blocks unloaded from a railroad car by means of the DFM-2 system does not take more than 1.5 min. Use of the system eliminates manual operations.

  18. Comparison between nasal endoscopic suction cutter treatment of adenoidal hypertrophy and blind adenoid scraping by spatula

    Institute of Scientific and Technical Information of China (English)

    Hong-Xia Zhang; Zhu-Lin Chen; Duo-Xi Mao; Jing Liu

    2016-01-01

    Objective:To analyze the wound degree during suction cutter treatment of adenoidal hypertrophy and its effect on postoperative ventilation function.Methods: A total of 112 patients with adenoidal hypertrophy were randomly divided into observation group and control group (n=56), control group received blind adenoid scraping by spatula, observation group received suction cutter treatment, and then differences in serum levels of inflammatory cytokines and apoptosis factors as well as nasal ventilation function and lung function indexes were compared between two groups of patients after treatment.Results:Inflammatory cytokines IL-4, IL-6, TNF-α, ECP and ICAM-1 content in serum of observation group 2d after treatment were lower than those of control group, and apoptotic factors survivin, caspase-3, sFas and sFasL content in serum were lower than those of control group (P<0.05); nasal ventilation function parameters TIR, TER, NPRi and NPRe levels of observation group 1 week after treatment were lower than those of control group while IC and EC levels were higher than those of control group, and pulmonary function parameters VT, MV, PIEF, FEF25%, FEF50% and FEF75% levels were higher than those of control group (P<0.05). Conclusions:Suction cutter treatment of adenoid hypertrophy outstandingly improves the patients’ ventilation function, and also has the advantage of small wound.

  19. Adaptive fuzzy integral sliding mode velocity control for the cutting system of a trench cutter

    Institute of Scientific and Technical Information of China (English)

    Qi-yan TIAN; Jian-hua WEI; Jin-hui FANG‡; Kai GUO

    2016-01-01

    This paper presents a velocity controller for the cutting system of a trench cutter (TC). The cutting velocity of a cutting system is affected by the unknown load characteristics of rock and soil. In addition, geological conditions vary with time. Due to the complex load characteristics of rock and soil, the cutting load torque of a cutter is related to the geological conditions and the feeding velocity of the cutter. Moreover, a cutter’s dynamic model is subjected to uncertainties with unknown effects on its function. In this study, to deal with the particular characteristics of a cutting system, a novel adaptive fuzzy integral sliding mode control (AFISMC) is designed for controlling cutting velocity. The model combines the robust characteristics of an integral sliding mode controller with the adaptive adjusting characteristics of an adaptive fuzzy controller. The AFISMC cutting velocity con-troller is synthesized using the backstepping technique. The stability of the whole system including the fuzzy inference system, integral sliding mode controller, and the cutting system is proven using the Lyapunov theory. Experiments have been conducted on a TC test bench with the AFISMC under different operating conditions. The experimental results demonstrate that the proposed AFISMC cutting velocity controller gives a superior and robust velocity tracking performance.

  20. Novel Material to Quantify Sharpness and Traction of Vitreous Cutters

    Directory of Open Access Journals (Sweden)

    Nazafarin Honarpisheh

    2011-01-01

    Full Text Available There is no available method for evaluating cutting quality of vitreotomes. The available methods of assessment allow only indirect judgment of their quality and are difficult to apply in clinical practice. We propose using a collagen film with maximum thickness of 1-2 micron to test the sharpness of instruments under conditions resembling clinical ones. The collagen film is fixed by a special device, then place in physiological saline, and then cut under the operation microscope. It shows whether the cutting edges are sharp enough, and the collagen film is cut smoothly. We also use an Electroforce 3100 machine and Dynamic Mechanical Analysis software to quantify the vitreoretinal force applied to the retina during vitrectomy.

  1. Feasibility investigations on multi-cutter milling process: A novel fabrication method for microreactors with multiple microchannels

    Energy Technology Data Exchange (ETDEWEB)

    Pan, Minqiang; Tang, Yong [School of Mechanical and Automotive Engineering, South China University of Technology, Guangzhou 510640 (China); Zeng, Dehuai [School of Mechanical and Automotive Engineering, South China University of Technology, Guangzhou 510640 (China); School of Mechatronics and Control Engineering, Shenzhen University, Shenzhen 518060 (China)

    2009-07-15

    A novel multi-cutter milling process for multiple parallel microchannels with manifolds is proposed to address the challenge of mass manufacture as required for cost-effective commercial applications. Several slotting cutters are stacked together to form a composite tool for machining microchannels simultaneously. The feasibility of this new fabrication process is experimentally investigated under different machining conditions and reaction characteristics of methanol steam reforming for hydrogen production. The influences of cutting parameters and the composite tool on the microchannel qualities and burr formation are analyzed. Experimental results indicate that larger cutting speed, smaller feed rate and cutting depth are in favor of obtaining relatively good microchannel qualities and small burrs. Of all the cutting parameters considered in these experiments, 94.2 m min{sup -1} cutting speed, 23.5 mm min{sup -1} feed rate and 0.5 mm cutting depth are found to be the optimum value. According to the comparisons of experimental results of multi-cutter milling process and estimated one of other alternative methods, it is found that multi-cutter milling process shows much shorter machining time and higher work removal rate than that of other alternative methods. Reaction characteristics of methanol steam reforming in microchannels also indicate that multi-cutter milling process is probably suitable for a commercial application. (author)

  2. Microbial community structure of leaf-cutter ant fungus gardens and refuse dumps.

    Directory of Open Access Journals (Sweden)

    Jarrod J Scott

    Full Text Available BACKGROUND: Leaf-cutter ants use fresh plant material to grow a mutualistic fungus that serves as the ants' primary food source. Within fungus gardens, various plant compounds are metabolized and transformed into nutrients suitable for ant consumption. This symbiotic association produces a large amount of refuse consisting primarily of partly degraded plant material. A leaf-cutter ant colony is thus divided into two spatially and chemically distinct environments that together represent a plant biomass degradation gradient. Little is known about the microbial community structure in gardens and dumps or variation between lab and field colonies. METHODOLOGY/PRINCIPAL FINDINGS: Using microbial membrane lipid analysis and a variety of community metrics, we assessed and compared the microbiota of fungus gardens and refuse dumps from both laboratory-maintained and field-collected colonies. We found that gardens contained a diverse and consistent community of microbes, dominated by Gram-negative bacteria, particularly gamma-Proteobacteria and Bacteroidetes. These findings were consistent across lab and field gardens, as well as host ant taxa. In contrast, dumps were enriched for Gram-positive and anaerobic bacteria. Broad-scale clustering analyses revealed that community relatedness between samples reflected system component (gardens/dumps rather than colony source (lab/field. At finer scales samples clustered according to colony source. CONCLUSIONS/SIGNIFICANCE: Here we report the first comparative analysis of the microbiota from leaf-cutter ant colonies. Our work reveals the presence of two distinct communities: one in the fungus garden and the other in the refuse dump. Though we find some effect of colony source on community structure, our data indicate the presence of consistently associated microbes within gardens and dumps. Substrate composition and system component appear to be the most important factor in structuring the microbial communities

  3. The maintenance and modiifcation of Goebel pony roll cutter and its innovative development%Goebel盘纸分切机维修改造与创新开发

    Institute of Scientific and Technical Information of China (English)

    李长国; 李艳平

    2015-01-01

    In this paper were introduced the structure of Rapid-d1250 pony roll cutter made by Goebel and the experience on the maintenance and modification to an old pony roll cutter by Henan Dazhi. Based on the experiences on design and application of pony roll cutter more than 10 years, a kind of special pony roll cutter was developed through the digestion and absorption with the imported cutter.%介绍了Goebel产Rapid-d1250型盘纸分切机的各部分结构和河南大指公司对旧盘纸分切机维修改造的经验。对进口设备进行消化吸收,结合本企业十多年使用和设计分切机的经验,开发出具有独特结构的盘纸分切机。

  4. Design and research of calculation models of the tooth profile angles of thread milling cutter with helical flutes

    Directory of Open Access Journals (Sweden)

    O. V. Malkov

    2014-01-01

    Full Text Available The review of manufacturer's programs to make thread milling cutters has shown that most of milling cutters are produced with the helical flutes with the ω slope angle within the range of 10° ...30°. Thus, thread milling cutters, made of high speed steels, essentially, are not produced. In Russia there is GOST 1336-77, to regulate the parameters of thread milling cutter shaving with a straight flutes, made of high speed steels.It is established that available rake and clearance angles, and inclination angle of helical flutes at the accepted values of pitch and diameter of the tool lead to obtaining the angles of the tooth profile other than 30 degrees, thus requiring the calculation of angles β1 and β2 in each case of design. In the general case we have an asymmetrical profile with respect to the axis passing through the top of the tooth.Using the CATIA V5 R17 software, a geometric model that allows us to determine the angles of the tooth profile of thread milling cutter with helical flutes has been developed. The model research has been conducted for geometric and design parameters of thread milling cutter, made of cemented carbide and high speed steel. The paper presents a method for constructing models and key assumptions adopted for its development.Dependences are obtained for the model with a variation of the five factors (external diameter d, step profiles, P, rake γтц, clearance α, inclination angle of helical flutes ω for thread milling cutters, made of cemented carbide and according to the model that extends the range of variation factors (d, P, γтц, ω according to GOST 1336-77. Thus, this model to have the angles of the tooth profile of thread milling cutter with helical flutes can be used both to obtain the angles profile β1 and β2 in a wide range of varying tool parameters for all types of tool materials, and to broaden the possibilities for calculation of parameters according to GOST 1336-77.

  5. Casting Process Optimization of φ1300 Vertical Grinder Base%φ1300立式磨底座的铸造工艺改进

    Institute of Scientific and Technical Information of China (English)

    米国发; 郑喜平; 南红艳

    2011-01-01

    运用V-Cast软件对铸钢件φ1300立式磨底座铸造工艺进行凝固过程模拟,分析缩孔、缩松缺陷产生的原因.根据模拟结果,添加了冒口和保温材料,以优化工艺;最终获得了合适的工艺,消除了缩孔、缩松缺陷,保证了铸件质量.%he solidification of initial scheme of φ1300 vertical grinder base was simulated by V-Cast software, and the causes of the shrinkage defects were analyzed. Based on the simulation resul.the riser and insolating materials were increased to optimize process. The appropriate casting process is gained and the casting quality is ensured at last

  6. Meat batter production in an extended vane pump-grinder injecting curing salt solutions to reduce energy requirements: variation of curing salt amount injected with the solution.

    Science.gov (United States)

    Irmscher, Stefan B; Terjung, Eva-Maria; Gibis, Monika; Herrmann, Kurt; Kohlus, Reinhard; Weiss, Jochen

    2017-01-01

    The integration of a nozzle in an extended vane pump-grinder system may enable the continuous injection of curing salt solutions during meat batter production. The purpose of this work was to examine the influence of the curing salt amount injected with the solution (0-100%) on protein solubilisation, water-binding, structure, colour and texture of emulsion-type sausages. The amount of myofibrillar protein solubilised during homogenisation varied slightly from 33 to 36 g kg(-1) . Reddening was not noticeably impacted by the later addition of nitrite. L(*) ranged from 66.9 ± 0.3 to 67.8 ± 0.3, a(*) from 10.9 ± 0.1 to 11.2 ± 0.1 and b(*) from 7.7 ± 0.1 to 8.0 ± 0.1. Although softer sausages were produced when only water was injected, firmness increased with increasing curing salt amount injected and was similar to the control when the full amount of salt was used. The substitution of two-thirds of ice with a liquid brine may enable energy savings due to reduced power consumptions of the extended vane pump-grinder system by up to 23%. The injection of curing salt solutions is feasible without affecting structure and colour negatively. This constitutes a first step towards of an 'ice-free' meat batter production allowing for substantial energy savings due to lower comminution work. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  7. Application of Siemens System Reforming on NC Grinder%西门子系统在数控磨床改造上的应用

    Institute of Scientific and Technical Information of China (English)

    杜柳青; 吴泽钊; 佘骋南

    2012-01-01

    针对M2060成型磨床的结构特点,提出了磨床的总体改造方案和硬件构成,搭建了硬件平台。介绍了西门子840D系统参数设置和驱动配置的方法。结合成型磨床加工的工艺流程特点,阐述了如何运用NC高级指令编写磨床加工程序和解决坐标零点自动校正问题,分析了西门子S7-300 PLC的工作原理及并介绍了其应用情况。改造后的磨床运转可靠,达到了改造目标,产生了经济效益。%Considering the construction features of M2060 forming grinder, the overall reform plan and hardware structure were put forward to set up the hardware platform. Siemens 840D system parameter setting and the method of drive configuration were introduced. Considering the character of forming grinder process, the method using NC senior instructions to program and solving problem with automatic correction of coordinates zero was expounded, and working principle and application of Siemens S7-300 PLC were analyzed. It operated reliably and achieved the goal of reform after reform. It made great economic benefits.

  8. 一种精密曲线磨床运动建模及实验%The Motion Model Building and Experiment of a Precision Curve Grinder

    Institute of Scientific and Technical Information of China (English)

    李干; 王贺; 卢书; 王勇

    2011-01-01

    根据磨床各平台相对运动关系,建立工件坐标系作为参考坐标系,将砂轮磨削运动分解到工件母线的切向、法向和旋转方向上,即分别代表机床下台、中台的平移和上台的旋转,推导出了工件磨削加工过程的一般模型,并进行了模拟计算.分析了模型加工误差,以加工曲线相对理论曲线的法向误差表征局部误差,以法向误差的峰峰值表征曲线轮廓度.实例的计算结果表明:机床模拟磨削加工的工件轮廓度为3.3 μm,实现了特殊工件的精密加工.%Based on the relative motion of each platform of the grinder, the workpiece coordinate system was set as a reference, the movement of the grinding wheel was split into three directions of tangential, normal and rotation, which represented separately the parallel move of middle and lower tables, and the rotation of upper table. The common motion model of grinder was built and simulated. The machining error of model was analyzed, and the normal deviation between machining curve and theoretical curve was used to characterize the part accuracy, the peak to peak value of normal deviation was used to characterize the curve profile. The simulation experiments of a workpiece were conducted with the curve profile of 3. 3 μm. So precision machining of special workpieces is realized.

  9. DEVELOPMENT AND PERFORMANCE EVALUATION OF TRACTOR FRONT MOUNTED PIGEON PEA STEM CUTTER

    Directory of Open Access Journals (Sweden)

    Atul R. Dange

    2010-07-01

    Full Text Available Pigeon pea or tur (Cajanus cajan L. Mills. is one of the important pulse crops of India and ranks second to chickpea in area and production. Traditionally the harvesting of pigeon pea is done manually by sickle, which demands considerable amount of labour, drudgery, time and cost to harvest, which reflects on total production cost of the crop. In view of this a tractor operated front mounted pigeon pea stem cutter was developed and being front mounted implement it facilitated better visibility and control to operator. The power was transmitted from pto to gear box. Arrangement of hydraulic cylinder and hydraulic motor was provided on the equipment to facilitate the height of cut and to rotate the conveyer belt. During comparative performance evaluation of developed equipment, the average cutting efficiency and field capacity was found 96.30 % and 0.176 ha/hr respectively. There was increase in fuel consumption and plant damage with increase in speed of operation. The average operation cost of newly developed tractor operated front mounted pigeon pea stem cutter was 64.71% less as compared with manual harvesting of pigeon pea crop. The time saved was almost 1/3rd to that of manual harvesting.

  10. The fungus gardens of leaf-cutter ants undergo a distinct physiological transition during biomass degradation

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Eric L.; Aylward, Frank O.; Kim, Young-Mo; Webb-Robertson, Bobbie-Jo M.; Nicora, Carrie D.; Hu, Zeping; Metz, Thomas O.; Lipton, Mary S.; Smith, Richard D.; Currie, Cameron R.; Burnum-Johnson, Kristin E.

    2014-08-01

    Leaf-cutter ants are dominant herbivores in ecosystems throughout the Neotropics. Rather than directly consuming the fresh foliar biomass they harvest, these ants use it to cultivate specialized fungus gardens. Although recent investigations have shed light on how plant biomass is degraded in fungus gardens, the cycling of nutrients that takes place in these specialized microbial ecosystems is still not well understood. Here, using metametabolomics and metaproteomics techniques, we examine the dynamics of nutrient turnover and biosynthesis in these gardens. Our results reveal that numerous free amino acids and sugars are depleted throughout the process of biomass degradation, indicating that easily accessible nutrients from plant material are readily consumed by microbes in these ecosystems. Accumulation of cellobiose and lignin derivatives near the end of the degradation process is consistent with previous findings of cellulases and laccases produced by Leucoagaricus gongylophorus, the fungus cultivated by leaf-cutter ants. Our results also suggest that ureides may be an important source of nitrogen in fungus gardens, especially during nitrogen-limiting conditions. No free arginine was detected in our metametabolomics experiments despite evidence that the host ants cannot produce this amino acid, suggesting that biosynthesis of this metabolite may be tightly regulated in the fungus garden. These results provide new insights into the dynamics of nutrient cycling that underlie this important ant-fungus symbiosis.

  11. Leucoagaricus gongylophorus Produces Diverse Enzymes for the Degradation of Recalcitrant Plant Polymers in Leaf-Cutter Ant Fungus Gardens

    Energy Technology Data Exchange (ETDEWEB)

    Aylward, Frank O. [Univ. of Wisconsin, Madison, WI (United States); Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Burnum-Johnson, Kristin E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Tringe, Susannah G. [Dept. of Energy Joint Genome Inst., Walnut Creek, CA (United States); Teiling, Clotilde [Roche Diagnostics, Indianapolis, IN (United States); Tremmel, Daniel [Univ. of Wisconsin, Madison, WI (United States); Moeller, Joseph [Univ. of Wisconsin, Madison, WI (United States); Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Scott, Jarrod J. [Univ. of Wisconsin, Madison, WI (United States); Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Barry, Kerrie W. [Dept. of Energy Joint Genome Inst., Walnut Creek, CA (United States); Piehowski, Paul D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Nicora, Carrie D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Malfatti, Stephanie [Dept. of Energy Joint Genome Inst., Walnut Creek, CA (United States); Monroe, Matthew E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Purvine, Samuel O. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Goodwin, Lynne A. [Dept. of Energy Joint Genome Inst., Walnut Creek, CA (United States); Smith, Richard D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Weinstock, George [Washington Univ. School of Medicine, St. Louis, MS (United States); Gerardo, Nicole [Emory Univ., Atlanta, GA (United States); Suen, Garret [Dept. of Energy Joint Genome Inst., Walnut Creek, CA (United States); Lipton, Mary S. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Currie, Cameron R. [Univ. of Wisconsin, Madison, WI (United States); Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Smothsonian Tropical Research Inst., Balboa (Panama)

    2013-06-12

    Plants represent a large reservoir of organic carbon comprised largely of recalcitrant polymers that most metazoans are unable to deconstruct. Many herbivores gain access to nutrients in this material indirectly by associating with microbial symbionts, and leaf-cutter ants are a paradigmatic example. These ants use fresh foliar biomass as manure to cultivate fungus gardens composed primarily of Leucoagaricus gongylophorus, a basidiomycetous symbiont that produces specialized hyphal swellings that serve as a food source for the host ant colony. Although leaf-cutter ants are conspicuous herbivores that contribute substantially to carbon turnover in Neotropical ecosystems, the process through which plant biomass is degraded in their fungus gardens is not well understood. Here we present the first draft genome of L. gongylophorus, and using genomic, metaproteomic, and phylogenetic tools we investigate its role in lignocellulose degradation in the fungus gardens of both Atta cephalotes and Acromyrmex echinatior leaf-cutter ants. We show that L. gongylophorus produces a diversity of lignocellulases in fungus gardens, and is likely the primary driver of plant biomass degradation in these ecosystems. We also show that this fungus produces distinct sets of lignocellulases throughout the different stages of biomass degradation, including numerous cellulases and laccases that may be playing an important but previously uncharacterized role in lignocellulose degradation. Our study provides a comprehensive analysis of plant biomass degradation in leaf-cutter ant fungus gardens and provides insight into the molecular dynamics underlying the symbiosis between these dominant herbivores and their obligate fungal cultivar.

  12. Complete Genome of Enterobacteriaceae Bacterium Strain FGI 57, a Strain Associated with Leaf-Cutter Ant Fungus Gardens.

    Science.gov (United States)

    Aylward, Frank O; Tremmel, Daniel M; Bruce, David C; Chain, Patrick; Chen, Amy; Walston Davenport, Karen; Detter, Chris; Han, Cliff S; Han, James; Huntemann, Marcel; Ivanova, Natalia N; Kyrpides, Nikos C; Markowitz, Victor; Mavrommatis, Kostas; Nolan, Matt; Pagani, Ioanna; Pati, Amrita; Pitluck, Sam; Deshpande, Shweta; Goodwin, Lynne; Woyke, Tanja; Currie, Cameron R

    2013-01-01

    The Enterobacteriaceae bacterium strain FGI 57 was isolated from a fungus garden of the leaf-cutter ant Atta colombica. Analysis of its single 4.76-Mbp chromosome will shed light on community dynamics and plant biomass degradation in ant fungus gardens.

  13. An Attachable Electromagnetic Energy Harvester Driven Wireless Sensing System Demonstrating Milling-Processes and Cutter-Wear/Breakage-Condition Monitoring

    Directory of Open Access Journals (Sweden)

    Tien-Kan Chung

    2016-02-01

    Full Text Available An attachable electromagnetic-energy-harvester driven wireless vibration-sensing system for monitoring milling-processes and cutter-wear/breakage-conditions is demonstrated. The system includes an electromagnetic energy harvester, three single-axis Micro Electro-Mechanical Systems (MEMS accelerometers, a wireless chip module, and corresponding circuits. The harvester consisting of magnets with a coil uses electromagnetic induction to harness mechanical energy produced by the rotating spindle in milling processes and consequently convert the harnessed energy to electrical output. The electrical output is rectified by the rectification circuit to power the accelerometers and wireless chip module. The harvester, circuits, accelerometer, and wireless chip are integrated as an energy-harvester driven wireless vibration-sensing system. Therefore, this completes a self-powered wireless vibration sensing system. For system testing, a numerical-controlled machining tool with various milling processes is used. According to the test results, the system is fully self-powered and able to successfully sense vibration in the milling processes. Furthermore, by analyzing the vibration signals (i.e., through analyzing the electrical outputs of the accelerometers, criteria are successfully established for the system for real-time accurate simulations of the milling-processes and cutter-conditions (such as cutter-wear conditions and cutter-breaking occurrence. Due to these results, our approach can be applied to most milling and other machining machines in factories to realize more smart machining technologies.

  14. An Attachable Electromagnetic Energy Harvester Driven Wireless Sensing System Demonstrating Milling-Processes and Cutter-Wear/Breakage-Condition Monitoring.

    Science.gov (United States)

    Chung, Tien-Kan; Yeh, Po-Chen; Lee, Hao; Lin, Cheng-Mao; Tseng, Chia-Yung; Lo, Wen-Tuan; Wang, Chieh-Min; Wang, Wen-Chin; Tu, Chi-Jen; Tasi, Pei-Yuan; Chang, Jui-Wen

    2016-02-23

    An attachable electromagnetic-energy-harvester driven wireless vibration-sensing system for monitoring milling-processes and cutter-wear/breakage-conditions is demonstrated. The system includes an electromagnetic energy harvester, three single-axis Micro Electro-Mechanical Systems (MEMS) accelerometers, a wireless chip module, and corresponding circuits. The harvester consisting of magnets with a coil uses electromagnetic induction to harness mechanical energy produced by the rotating spindle in milling processes and consequently convert the harnessed energy to electrical output. The electrical output is rectified by the rectification circuit to power the accelerometers and wireless chip module. The harvester, circuits, accelerometer, and wireless chip are integrated as an energy-harvester driven wireless vibration-sensing system. Therefore, this completes a self-powered wireless vibration sensing system. For system testing, a numerical-controlled machining tool with various milling processes is used. According to the test results, the system is fully self-powered and able to successfully sense vibration in the milling processes. Furthermore, by analyzing the vibration signals (i.e., through analyzing the electrical outputs of the accelerometers), criteria are successfully established for the system for real-time accurate simulations of the milling-processes and cutter-conditions (such as cutter-wear conditions and cutter-breaking occurrence). Due to these results, our approach can be applied to most milling and other machining machines in factories to realize more smart machining technologies.

  15. Leucoagaricus gongylophorus produces diverse enzymes for the degradation of recalcitrant plant polymers in leaf-cutter ant fungus gardens.

    Science.gov (United States)

    Aylward, Frank O; Burnum-Johnson, Kristin E; Tringe, Susannah G; Teiling, Clotilde; Tremmel, Daniel M; Moeller, Joseph A; Scott, Jarrod J; Barry, Kerrie W; Piehowski, Paul D; Nicora, Carrie D; Malfatti, Stephanie A; Monroe, Matthew E; Purvine, Samuel O; Goodwin, Lynne A; Smith, Richard D; Weinstock, George M; Gerardo, Nicole M; Suen, Garret; Lipton, Mary S; Currie, Cameron R

    2013-06-01

    Plants represent a large reservoir of organic carbon comprised primarily of recalcitrant polymers that most metazoans are unable to deconstruct. Many herbivores gain access to nutrients in this material indirectly by associating with microbial symbionts, and leaf-cutter ants are a paradigmatic example. These ants use fresh foliar biomass as manure to cultivate gardens composed primarily of Leucoagaricus gongylophorus, a basidiomycetous fungus that produces specialized hyphal swellings that serve as a food source for the host ant colony. Although leaf-cutter ants are conspicuous herbivores that contribute substantially to carbon turnover in Neotropical ecosystems, the process through which plant biomass is degraded in their fungus gardens is not well understood. Here we present the first draft genome of L. gongylophorus, and, using genomic and metaproteomic tools, we investigate its role in lignocellulose degradation in the gardens of both Atta cephalotes and Acromyrmex echinatior leaf-cutter ants. We show that L. gongylophorus produces a diversity of lignocellulases in ant gardens and is likely the primary driver of plant biomass degradation in these ecosystems. We also show that this fungus produces distinct sets of lignocellulases throughout the different stages of biomass degradation, including numerous cellulases and laccases that likely play an important role in lignocellulose degradation. Our study provides a detailed analysis of plant biomass degradation in leaf-cutter ant fungus gardens and insight into the enzymes underlying the symbiosis between these dominant herbivores and their obligate fungal cultivar.

  16. The Application of Grinding Wheel Trimming Formation in Cylindrical Grinder Transformation%数控化改造外圆磨床砂轮成形修整的应用

    Institute of Scientific and Technical Information of China (English)

    邵迪骏; 樊留群

    2011-01-01

    介绍了基于国产经济型开通数控系统改造的数控外圆磨床MKA1320/H的方法,针对数控外圆磨床复杂曲面砂轮的成形修整问题进行研究,通过开通数控开放式编程环境,完成了砂轮成形修整的数控编程,最后给出了完整程序.%This paper introduces a method which is applied in transformation of the CNC cylindrical grinder MKA1320/H based on CAPITAL CNC system. The trimming formation problem of complex grinding wheel surface relating to CNC cylindrical grinder is researched. Through the opening of CAPITAL CNC programming environment, a NC program for grinding wheel trimming formation is accomplished. Finally, a complete program is given.

  17. The principle of second generation wavelet for milling cutter breakage detection

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Performance degradation or failure of manufacturing equipment will badly influence machining quality.Because of discontinuousness of the milling process,dynamic signals produced in the milling process become non-stationary.This paper indicates that the essence of SGW(second generation wavelet) transform in non-stationary signal processing is the mathematics principle of inner product transform of a dynamic signal with basis functions.Namely,by means of the inner product operation of a signal with basis functions containing scale function and wavelet function,signal decomposition and reconstruction are obtained.Acoustic emission signals generated in the milling processes of a CNC machine were analyzed by using the basis functions of SGW which are oscillation,decay and compact support.The features of end milling cutter breakage have been extracted,and the influences on machining surface quality have been identified effectively,which provide scientific bases for fault diagnosis,error tracing and quality control.

  18. The Evolutionary Innovation of Nutritional Symbioses in Leaf-Cutter Ants

    Directory of Open Access Journals (Sweden)

    Frank O. Aylward

    2012-01-01

    Full Text Available Fungus-growing ants gain access to nutrients stored in plant biomass through their association with a mutualistic fungus they grow for food. This 50 million-year-old obligate mutualism likely facilitated some of these species becoming dominant Neotropical herbivores that can achieve immense colony sizes. Recent culture-independent investigations have shed light on the conversion of plant biomass into nutrients within ant fungus gardens, revealing that this process involves both the fungal cultivar and a symbiotic community of bacteria including Enterobacter, Klebsiella, and Pantoea species. Moreover, the genome sequences of the leaf-cutter ants Atta cephalotes and Acromyrmex echinatior have provided key insights into how this symbiosis has shaped the evolution of these ants at a genetic level. Here we summarize the findings of recent research on the microbial community dynamics within fungus-growing ant fungus gardens and discuss their implications for this ancient symbiosis.

  19. Development of a cutter-chipper prototype for tree stands; Pystypuuston katkaisuhakettimen proto

    Energy Technology Data Exchange (ETDEWEB)

    Polus, P. [Tmi P. Polus, Raahe (Finland)

    1997-12-01

    Collection of chips and energy wood with conventional methods involves too many operations and hence results in a too high price of chips. The aim of the project was to develop a cutter-chipper suitable for chipping energy and pulp wood from tree stands. This equipment cuts and chips growing trees with branches and tops at site. Many stages involved in chipping would be eliminated and hence the price of chips would be more competitive, for example, with that of peat. In preliminary experiments, the prototype operated as expected. The product chips were homogeneous, did not contain long fractions or branch bits, and the chip size was. The chips were moved into the container by a conveyor. The sale of manufacturing rights for the equipment is under consideration. (orig.)

  20. The principle of second generation wavelet for milling cutter breakage detection

    Institute of Scientific and Technical Information of China (English)

    HE ZhengJia; CAO HongRui; LI Zhen; ZI YanYang; CHEN XueFeng

    2009-01-01

    Performance degradation or failure of manufacturing equipment will badly influence machining quality.Because of discontinuousness of the milling process, dynamic signals produced in the milling process become non-stationary. This paper indicates that the essence of SGW (second generation wavelet)transform in non-stationary signal processing is the mathematics principle of inner product transform of a dynamic signal with basis functions. Namely, by means of the inner product operation of a signal with basis functions containing scale function and wavelet function, signal decomposition and recon-struction are obtained. Acoustic emission signals generated in the milling processes of a CNC machine were analyzed by using the basis functions of SGW which are oscillation, decay and compact support.The features of end milling cutter breakage have been extracted, and the influences on machining surface quality have been identified effectively, which provide scientific bases for fault diagnosis, error tracing and quality control.

  1. Global optimization of tool path for five-axis flank milling with a cylindrical cutter

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    In this paper, optimum positioning of cylindrical cutter for five-axis flank milling of non-developable ruled surface is addressed from the perspective of surface approximation. Based on the developed interchangeability principle, global optimization of the five-axis tool path is modeled as approximation of the tool envelope surface to the data points on the design surface following the minimum zone criterion recommended by ANSI and ISO standards for tolerance evaluation. By using the signed point-to-surface distance function, tool path plannings for semi-finish and finish millings are formulated as two constrained optimization problems in a unified framework. Based on the second order Taylor approximation of the distance function, a sequential approximation algorithm along with a hierarchical algorithmic structure is developed for the optimization. Numerical examples are presented to confirm the validity of the proposed approach.

  2. Fatigue fracture of cutter blade made of high-speed steel

    Directory of Open Access Journals (Sweden)

    Beata Letkowska

    2015-04-01

    Full Text Available The quality of the surface of cyclically loaded components is very important. Many observations confirm that the root cause of the micro cracks (causing the fatigue fracture are primarily a surface's defects appearing during production process. These surface defects can be also caused by engraving processes used to perform identification marks. This paper presents the failure analysis of broken blade of the cutter Ku 500VX. The blade was subject of standard metallographic examination, hardness measurements, fractography analysis and metallographic studies using stereoscopic, light and scanning electron microscopes. The damage of the blade was caused by changes of the structure (formation of the brittle micro dendritic structure that occurred during manual electric engraving process when the material was heated till its melting point. As a result the stresses occurred in surface what provided to micro cracking and to propagate the fatigue fracture. The origin of this fatigue fracture was in the place where the inscription was made.

  3. Global optimization of tool path for five-axis flank milling with a cylindrical cutter

    Institute of Scientific and Technical Information of China (English)

    DING Han; ZHU LiMin

    2009-01-01

    In this paper,optimum positioning of cylindrical cutter for five-axis flank milling of non-developable ruled surface is addressed from the perspective of surface approximation.Based on the developed interchangeability principle,global optimization of the five-axis tool path is modeled as approximation of the tool envelope surface to the data points on the design surface following the minimum zone criterion recommended by ANSI and ISO standards for tolerance evaluation.By using the signed point-to-surface distance function,tool path plannings for semi-finish and finish millings are formulated as two constrained optimization problems in a unified framework.Based on the second order Taylor approximation of the distance function,a sequential approximation algorithm along with a hierarchical algorithmic structure is developed for the optimization.Numerical examples are presented to confirm the validity of the proposed approach.

  4. Simulation and analysis of aerodynamics for high speed face milling cutters

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    In high speed face milling,noise can be broadly categorized as idling noise and cutting noise.Idling noise mainly consists of aerodynamic noise.A mathematical model is developed based on the Ffowcs Williams-Hawkings Equation.The noise predicted with the mathematical model compares well with the experimental observations.The characteristics of aerodynamic noise with the different model parameters (number of teeth,tooth spacing) and locations of observation points are investigated.The directivity of noise is found and the peak value of sound power can be moved from the rotating frequency to higher frequency.This investigation can provide theoretical foundation for the design of face milling cutters with low noise.

  5. Hydraulic Resistance of Vitreous Cutters: The Impact of Blade Design and Cut Rate

    Science.gov (United States)

    Rossi, Tommaso; Querzoli, Giorgio; Angelini, Giampiero; Malvasi, Carlo; Rossi, Alessandro; Morini, Mario; Esposito, Graziana; Micera, Alessandra; di Luca, Natale Mario; Ripandelli, Guido

    2016-01-01

    Purpose To measure the hydraulic resistance (HR) of vitreous cutters equipped with a Regular guillotine Blade (RB) or double edge blade (DEB) at cut rates comprised between 0 and 12,000 cuts per minute (CPM) and compare it with vitreous fragment size. This was an in vitro experimental study; in vivo HR measure and vitreous sampling. Methods HR, defined as aspiration pressure/flow rate, was measured in balanced salt solution (BSS; Alcon, Fort Worth, TX) (in vitro) and during pars plana vitrectomy of 20 consecutive patients aged 18 to 65, undergoing macular surgery. HR was recorded at increasing cut rates (500–6000 CPM for the RB and 500–12,000 CPM for the DEB; 5 mL/min flow). Vitreous samples were withdrawn and analyzed with Western and collagen type II and IX immunostaining to evaluate protein size. The main outcome measures were hydraulic resistance (mm Hg/ml/min [±SD]) and optic density for Western blot and immunostaining. Results RB and DEB showed identical HR in BSS between 0 and 3000 CPM. Above 3000 CPM, RB HR steadily increased, and was significantly higher than DEB HR. Vitreous HR was also similar for the two blades between 0 and 1500 CPM. Above 1500 CPM, RB offered a significantly higher resistance. Western blot and immunostaining of vitreous samples did not yield a significant difference in size, regardless of blade type and cut rate. Conclusions DEB is more efficient, offering a lower HR than RB over 1500 CPM in human vitreous. There is no viscosity reduction as a function of cut-rate between 1500 and 12,000 CPM, as HR does not vary. Translational Relevance Future vitreous cutters will benefit of a DEB; optimal cut rate needs to be defined, and the simple increase of cut rate does not provide benefits after a certain limit to be assessed. PMID:27441099

  6. 水射流辅助刀具切削钴结壳%Water jet assist cutter cutting cobalt crusts

    Institute of Scientific and Technical Information of China (English)

    黄中华; 谢雅

    2012-01-01

    In order to reduce impact load and improve working safety of miner, deepsea cobalt crusts cutting method of water jet assist cutter was proposed. Stress analysis of cutter cutting cobalt crusts with single teeth was analyzed and mechanical model of water jet assist cutter cutting deepsea cobalt crusts was established. With simulation calculation, the relationship between water jet pressure and minimum cutting force of cutter was obtained, which was needed to generate initial crack on cobalt crust surface. Simulation results are as follows; compared with cutter cutting, when water jet working point is overlap with cutter working point, the minimum cutting force is decreased. With the increasing of water jet pressure, the minimum cutting force decreased dramatic. Experiments of water jet assist cutter cutting cobalt crusts simulation material were carried out. Experimental results are as follows; compared with cutter cutting, the maximum impact load is decreased when water jet assist cutter cutting cobalt crusts. When water jet pressure is 5 Mpa, the maximum impact load is decreased by 50% and the RMS impact load is decreased by 10%.%为了减小钴结壳切削过程中产生的冲击载荷,提高集矿机的行走安全性,提出了水射流辅助刀具切削钴结壳的切削方法.分析了单个截齿切削钴结壳时的受力情况,建立了水射流辅助刀具切削钴结壳的力学模型,通过仿真计算获取了水射流压力和刀具在钴结壳表面产生初始裂纹所需最小切削力的作用规律.仿真结果表明:与纯刀具切削相比,当水射流作用点和刀具作用点重合时,刀具在钴结壳表面产生初始裂纹所需的最小切削力明显下降;随着水射流压力的增加,刀具所需的最小切削力急剧下降.开展了水射流辅助刀具切削钴结壳模拟料实验.实验结果表明:与纯刀具切削钴结亮相比,水射流辅助刀具切削钴结壳时,切削过程中冲击载荷的最大值明

  7. Versatility of viewpoint and creativity. Development of high performance plasma cutter; Shiten no tayosei to sozosei. Koseino plasma setsudanki no kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    Sakuragi, S. [Komatsu Electronic Metals Co., Hiratsuka, Kanagawa (Japan)

    1998-07-05

    Ten years ago, CO2 laser cutters were mainly used to cut sheet metal less than 6 mm thick. However the operation cost of the cutter was expensive. Therefore the author developed a high performance plasma cutter; its operation cost is low. The main subject, `Versatility of Viewpoint and Creativity`, is described explaining the process of this development. The problems of developing the high performance plasma cutter are described first in detail. Then the author explained with examples how the versatility of viewpoint and creation of breakthrough ideas were made. Under the heading of `Essence for Breakthrough`, three important consideration process for solving technical problems are stated. Engineering essence is stated obtained from careful observations and long experiences of studies and developments. 3 refs., 5 figs.

  8. Study on Wear Mechanism of Slurry Shield Cutter%泥水盾构刀具磨损机理研究

    Institute of Scientific and Technical Information of China (English)

    陈志宁; 夏沅谱; 施烨辉; 蔡立艮

    2014-01-01

    泥水盾构刀具磨损受诸多因素的影响,文章在磨损基本理论的基础上,总结得出泥水盾构刀具的磨损类型及磨损过程的3个阶段,并用ABAQUS软件对磨损过程进行了模拟计算,计算分析了不同地层条件、刀具组合配置、刀具材料选择、刀具设计与制造工艺及掘进参数等对刀具磨损的影响。%Slurry shield cutter wear is affected by many factors. On the basis of wear basic theory, the paper makes a summary of three stages of slurry shield cutter wear and wear process. Using ABAQUS software to simulate and calculate the wear process, the paper analyzes and calculates the different formation conditions, configuration of cutters, cutter material selection, cutter design and manufacturing process and discuses the impact of the tunneling parameters on the cutter wear etc.

  9. Field evaluation of cutter and feeder mechanism of chickpea harvester for lentil harvesting

    Directory of Open Access Journals (Sweden)

    S Kamgar

    2016-09-01

    Full Text Available Introduction The main producers of lentil are Canada, India, Nepal and China, respectively and Iran is the ninth producer in the world. The hand pulling is the usual method of lentil harvesting. Use of conventional combine because of short leg varieties, wide combine head in dry land and grain losses by cutter bar vibrations is impossible. So a mechanism should be designed to harvest the lentil plants with minimum damage. This mechanism should be evaluated under different tests of crop and machines such as forward speed (FS, grain moisture content (GMC, different varieties and other parameters. Some researchers studied the effects of GMC (Andrews and et al., 1993; Huitink, 2005; Adisa, 2009; Abdi and Jalali, 2013 and FS on grain losses (Geng et al., 1984; Swapan et al., 2001; Mostafavand and Kamgar, 2014; Hunt, 1995. Field tests were conducted at three levels of FS 1.5, 3 and 4.5 km.h-1; three levels of cutting height (CH 4, 8 and 13 cm and two levels of GMC, 8 and 14% on two varieties of lentils including Flip and Shiraz with three replications. Materials and Methods The feeder and cutter mechanism for chickpea harvesting that was the base design of device which is notched wheel and counter shear, was used. The other components of device were dividers, slat and chain feeders, belt and pulleys, chassis, elevator conveyor and storage. Two split plot design based on a randomized complete design was used to determine the effects of above treatments on lentil losses. Results and Discussion The ANOVA results indicated that the all studied factors; FS of feeder and cutter mechanism, CH and GMC had significant effect on losses of Shiraz variety (P0.05. The ranges of losses of Flip variety at 8% GMC were 8.6 to 10% for FS of 1.5 km.h-1, 9.1 to 10.4% for FS of 3 km.h-1and 10.4 to 11.4% for FS of 4.5 km h-1. These ranges at 14% GMC were 7.9 to 8.9% for FS of 1.5 km.h-1, 8.4 to 9.2% for FS of 3 km.h-1and 8.5 to 10% for FS of 4.5 km h-1. The ranges of

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

    Institute of Scientific and Technical Information of China (English)

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

    2006-01-01

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

  11. Improvement and Experiment of the Reamer in Vibra Cutter Against Wave Edge of Titanium Sheet Alloy Parts

    Institute of Scientific and Technical Information of China (English)

    GENG Duan-yang; ZUO Hong-fu; ZHENG Bai-zhan; XU Tong

    2006-01-01

    By analyzing the influencing factors of part quality making of sheet alloy of titanium by vibra cutter, the shape of upper reamer is set as cylinder and wedge-shaped form, and the lower reamer as plain and hemicycle form, and its main structural parameters are defined as well. Then it is validated further that such improved vibra cutter reamer can be used to process curve-edged parts of titanium alloy sheet. The experimental result shows that the titanium alloy sheet parts processed by above equipment have no sharpen angles for convex parts and evident crevasse of concave-edged part. In summary, such improvement can eliminate the free-waved edge and improve the manufacture quality of titanium alloy sheet parts greatly.

  12. A New-type of Cermets Cutter with Nano-TiN Addition: Microstructure, Mechanical and Cutting Properties

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The microstructure and mechanical properties of a new- type of cermets cutter ( tool A ) with nano- TiN modification and its cutting properties in cutting gray cast iron are investigated.SEM and TEM observations of the microstructure of the above material reveal that nano- TiN modified cermets possess a finer microstructure than conventional cermets .In the cutting tests, for comparison, cemented carbide cutter ( YG8 , tool B) was also utilized.The cutting results show that the cutting properties of tool A are superior to those of tool B.It is also found that the predominant failure mode of tool A is normal wear and micro-spalling under lower cutting quantities, and that chipping occurs under higher cutting quantities.SEM analysis reveals that cohesion, oxidation and diffusion wear become very apparent at a higher cutting speed.On the contrary, grain wear also exists but is not apparent.

  13. The fungal cultivar of leaf-cutter ants produces specific enzymes in response to different plant substrates

    Energy Technology Data Exchange (ETDEWEB)

    Khadempour, Lily [Department of Bacteriology, University of Wisconsin-Madison, Madison WI 53706 USA; Department of Zoology, University of Wisconsin-Madison, Madison WI 53706 USA; Department of Energy Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison WI 53706 USA; Burnum-Johnson, Kristin E. [Biological Sciences Division, Pacific Northwest National Laboratory, Richland WA 99352 USA; Baker, Erin S. [Biological Sciences Division, Pacific Northwest National Laboratory, Richland WA 99352 USA; Nicora, Carrie D. [Biological Sciences Division, Pacific Northwest National Laboratory, Richland WA 99352 USA; Webb-Robertson, Bobbie-Jo M. [Biological Sciences Division, Pacific Northwest National Laboratory, Richland WA 99352 USA; White, Richard A. [Biological Sciences Division, Pacific Northwest National Laboratory, Richland WA 99352 USA; Monroe, Matthew E. [Biological Sciences Division, Pacific Northwest National Laboratory, Richland WA 99352 USA; Huang, Eric L. [Biological Sciences Division, Pacific Northwest National Laboratory, Richland WA 99352 USA; Smith, Richard D. [Biological Sciences Division, Pacific Northwest National Laboratory, Richland WA 99352 USA; Currie, Cameron R. [Department of Bacteriology, University of Wisconsin-Madison, Madison WI 53706 USA; Department of Energy Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison WI 53706 USA

    2016-10-26

    Herbivores use symbiotic microbes to help gain access to energy and nutrients from plant material. Leaf-cutter ants are a paradigmatic example, having tremendous impact on their ecosystems as dominant generalist herbivores through cultivation of a fungus, Leucoagaricus gongylophorous. Here we examine how this mutualism could facilitate the flexible substrate incorporation of the ants by providing leaf-cutter ant subcolonies four substrate types: leaves, flowers, oats, and a mixture of all three. Through metaproteomic analysis of the fungus gardens, we were able to identify and quantify 1766 different fungal proteins, including 161 biomass-degrading enzymes. This analysis revealed that fungal protein profiles were significantly different between subcolonies fed different substrates with the highest abundance of cellulolytic enzymes observed in the leaf and flower treatments. When the fungus garden is provided with leaves and flowers, which contain the majority of their energy in recalcitrant material, it increases its production of proteins that break down cellulose: endoglucanases, exoglucanase and β-glucosidase. Further, the complete metaproteomes for the leaves and flowers treatments were very similar, the mixed treatment closely resembled the treatment with oats alone. This suggests that when provided a mixture of substrates, the fungus garden preferentially produces enzymes necessary for breakdown of simpler, more digestible substrates. This flexible, substrate-specific response of the fungal cultivar allows the leaf-cutter ants to derive energy from a wide range of substrates, which may contribute to their ability to be dominant generalist herbivores.

  14. Efficacy of 23-gauge vitrectomy cutter replaeing scissors in conventional 20-gauge pars plana vitrectomy for severe PDR

    Directory of Open Access Journals (Sweden)

    Ling Gong

    2014-06-01

    Full Text Available AIM: To determine whether the 23-gauge(23Gvitrecomy cutter could replace scissors in conventional 20-gauge(20Gpars plana vitrectomy for treating severe proliferative diabetic retinopathy(PDR.METHODS:Non-comparative interventional case series. Totally 27 eyes of 27 patients with PDR stageⅥ confirmed by funduscopy and B-ultrasound scan were enrolled. They underwent 20G vitrectomy, in which 23G vitrectomy cutter replaced scissors to remove neuvascular membrane. All 27 eyes received complete panretinal photocoagulation, 17 eyes received no tamponade, 6 eyes were 12% C3F8 tamponade, 4 eyes were filled with silicone oil. The follow up time was 3mo. The operation duration time, iatrogenic retinal tear and retinal bleeding need electric coagulation, best corrected visual acuity(BCVA, retinal reattachment were analyzed.RESULTS: The operative time was 35-120(average 79.19±29.82min; intraoperative iatrogenic retinal breaks were detected in 2 eyes(7%. At the end of 3mo follow up, BCVA>0.1 were in 9 eyes, from 0.05-0.1 in 10 eyes, CONCLUSION: The 23G vitrectomy cutter could replace scissors in conventional 20G pars plana vitrectomy for treating severe PDR.

  15. 水射流辅助截齿破碎钴结壳%Cobalt Crusts Fractured by Cutter and Water Jet

    Institute of Scientific and Technical Information of China (English)

    黄中华; 谢雅

    2011-01-01

    建立了水射流辅助截齿破碎钴结壳的力学模型,通过仿真研究获取了水射流系统参数与截齿在钴结壳表面切出初始裂纹所需最小破碎力的作用规律.仿真结果表明:当水射流的作用点和截齿的作用点不. 重合时,水射流的辅助破碎不仅不能减小截齿所需的破碎力,反而会增加截齿所需的破碎力;当水射流的作用点和截齿的作用点重合时,水射流的辅助破碎能有效减小截齿所需的破碎力;与纯截齿破碎钴结壳相比,当水射流的压力为5 MPa时,截齿所需的破碎力下降幅度约为50%;随着水射流系统工作压力的增加,水射流系统的辅助破碎作用越强.%Mechanical model of fracturing the cobalt crusts by cutter and water jet was established. With simulation study, the relationship between water jet system parameters and cutter's minimum cutting force was obtained, which was needed to generate initial crack on cobalt crust surface. Simulation results show that when the working point of both water jet and cutter isn't overlap, water jet can't decrease cutter's minimum cutting force. Conversely, it will increase cutter's minimum cutting force. When water jet working point is overlap with cutter working point, water jet can decrease cutter's minimum cutting force obviously. Compared with cutter cutting alone, when water jet pressure is 5 Mpa, cutter's minimum cutting force is reduced by 50%. With water jet working pressure increasing, cutter's minimum cutting force is decreased correspondingly.

  16. QCD at Fixed Topology

    CERN Document Server

    Brower, Richard C; Negele, John W; Wiese, U J

    2003-01-01

    Since present Monte Carlo algorithms for lattice QCD may become trapped in a fixed topological charge sector, it is important to understand the effect of calculating at fixed topology. In this work, we show that although the restriction to a fixed topological sector becomes irrelevant in the infinite volume limit, it gives rise to characteristic finite size effects due to contributions from all $\\theta$-vacua. We calculate these effects and show how to extract physical results from numerical data obtained at fixed topology.

  17. Research on Cutter Layout Based on the Load Analysis%基于载荷分析的滚刀布局研究

    Institute of Scientific and Technical Information of China (English)

    刘建琴; 秦得昌; 郭伟

    2016-01-01

    In terms of the problem of the cutter load,cutter-head rotating speed and the cutter layout,nonlinear fi-nite element analysis software ABAQUS was employed to establish disc cutter rotating cutting model,which consid-ered the cutter's movement and the rock breaking mechanism. Compared with the linear cutting model,this model could simulate the working conditions of the cutter more authentically and was proved to be correct and feasible by the test data. On this basis,the relationship between the lateral force and the installation radius of cutter was studied;the relationship between cutter load,specific energy and operating parameters was also studied;change of adjacent cut-ters' load was analyzed under the two arrangements. The results show that cutter's lateral force becomes larger as the installation radius becomes smaller;cutter's vertical force and rolling force increase gradually with the increasing rotating speed and there exits an optimal combination between rotating speed and penetration. Lastly,the installation form of cutter was improved;combined with the principle of equal wear,the layout method of inner cutter advanc-ing outer cutter was proposed.%针对硬岩掘进机滚刀载荷、刀盘转速以及刀具布局问题,综合考虑滚刀破岩运动形式和破岩机理,应用非线性有限元分析软件ABAQUS建立了滚刀回转切削模型. 与线性切削模型相比,该模型可以更加真实地模拟滚刀工作情况,利用试验数据验证仿真模型的正确性与可行性. 在此基础上,研究了滚刀侧向力与安装半径的关系,以及滚刀载荷、比能与操作参数的关系,分析了相邻滚刀在两种布置情况下的载荷变化. 结果表明:滚刀侧向力随着安装半径变小而变大;滚刀的垂直力和滚动力随刀盘转速增加而增大,并且转速和切深之间存在最优的组合关系. 最后,改进滚刀的安装形式;结合等磨损的原则,提出了内侧滚刀超前外侧滚刀的布置方法.

  18. Association of Workplace Stressors with Salivary Alpha-Amyl-ase Activity Levels among Fresh Fruit Bunch Cutters in Se¬langor

    Directory of Open Access Journals (Sweden)

    Nur Sabrina MOHD NASIR

    2016-03-01

    Full Text Available Background: A cross sectional study was conducted to determine the association between occupational stress risk factors and salivary alpha-amylase activity levels among fresh fruit bunch (ffb cutters at oil palm plantation. Methods: A total of 109 ffb cutters were selected from two oil palm plantations in Pulau Carey, Selangor at west coast of Malaysia in 2015. Questionnaires were used to determine socio-demographics and occupation information, distress level were determined by using translated 12-items-General Health Questionnaire (GHQ. Kestrel Heat Stress Tracker 4400 was used to measure wet bulb globe temperature (WBGT for heat stress exposure. Posture analysis was examined based on Rapid Upper Limb Assessment (RULA method in evaluating working posture and Borg CR-10 scale was rated by ffb cutters to determine exerted force during harvesting process. Stress response system was determined by measuring salivary alpha-amylase (sAA activity by using sAA kinetic enzyme assay kit (Salimetrics.Results: 35.8% of ffb cutter had high score indicating psychological distress. 49.5% of the cutters had high heat stress exposure. 91.8% used force exertion of 50%MVC and above to cut fresh fruit bunches and 62.4% were classified in Action Level 4 under RULA. 77.0% of the ffb cutters showed high levels of sAA activity after cutting fresh fruit bunches. Conclusion: Workplace stressors such as working environment and ergonomics risk factors play a role to develop stress at workplace among ffb cutters. Therefore, stress preventive measures are needed to reduce the stressors at workplace.Keywords: Psychological distress, Salivary alpha-amylase, Heat stress exposure, Oil palm plantation

  19. Metagenomic and metaproteomic insights into bacterial communities in leaf-cutter ant fungus gardens.

    Science.gov (United States)

    Aylward, Frank O; Burnum, Kristin E; Scott, Jarrod J; Suen, Garret; Tringe, Susannah G; Adams, Sandra M; Barry, Kerrie W; Nicora, Carrie D; Piehowski, Paul D; Purvine, Samuel O; Starrett, Gabriel J; Goodwin, Lynne A; Smith, Richard D; Lipton, Mary S; Currie, Cameron R

    2012-09-01

    Herbivores gain access to nutrients stored in plant biomass largely by harnessing the metabolic activities of microbes. Leaf-cutter ants of the genus Atta are a hallmark example; these dominant neotropical herbivores cultivate symbiotic fungus gardens on large quantities of fresh plant forage. As the external digestive system of the ants, fungus gardens facilitate the production and sustenance of millions of workers. Using metagenomic and metaproteomic techniques, we characterize the bacterial diversity and physiological potential of fungus gardens from two species of Atta. Our analysis of over 1.2 Gbp of community metagenomic sequence and three 16S pyrotag libraries reveals that in addition to harboring the dominant fungal crop, these ecosystems contain abundant populations of Enterobacteriaceae, including the genera Enterobacter, Pantoea, Klebsiella, Citrobacter and Escherichia. We show that these bacterial communities possess genes associated with lignocellulose degradation and diverse biosynthetic pathways, suggesting that they play a role in nutrient cycling by converting the nitrogen-poor forage of the ants into B-vitamins, amino acids and other cellular components. Our metaproteomic analysis confirms that bacterial glycosyl hydrolases and proteins with putative biosynthetic functions are produced in both field-collected and laboratory-reared colonies. These results are consistent with the hypothesis that fungus gardens are specialized fungus-bacteria communities that convert plant material into energy for their ant hosts. Together with recent investigations into the microbial symbionts of vertebrates, our work underscores the importance of microbial communities in the ecology and evolution of herbivorous metazoans.

  20. The Research of the Measures Algorithm of the Parameter of the Cutter

    Directory of Open Access Journals (Sweden)

    S. Ya-ceng

    2011-02-01

    Full Text Available Edge detection is the most basic problem in the process of image processing. The precision of traditional edge detection algorithm is not very high, it unable to meet the high precision need of modern industrial test technology. In order to overcome the deficiency, this text proposed subpixel edge detection algorithm based on the function curve fitting-Gauss fitting of gradient direction sub-pixel edge detection algorithm. According to the gradient distribution of the image, this text use gauss curve fitting the edge in order to realize the sub-pixel location. This text compared this algorithm with sub-pixel edge detection based on the LOG operator and sub-pixel edge detection based on the quadratic, and draw that this algorithm not only have the short running time and high efficiency, but also has proved that the algorithm has rotation invariant through the experiment. It is that pattern recognition and picture measure the important pretreatment means in the course to follow the method at the border, contradiction at accuracy and speed that but follow the method and exist at the traditional border. To above-mentioned problems, this text proposes following algorithms at the border based on model, and then try to get the diameter of the cutter. The experiment shows this algorithm at the realization border that can be very good and follows, measure the comparison of the algorithm through two kinds of diameters, drawing the running time of least square method shorter, efficiency is relatively high.

  1. Metagenomic and metaproteomic insights into bacterial communities in leaf-cutter ant fungus gardens

    Energy Technology Data Exchange (ETDEWEB)

    Aylward, Frank O.; Burnum, Kristin E.; Scott, Jarrod J.; Suen, Garret; Tringe, Susannah G.; Adams, Sandra M.; Barry, Kerrie W.; Nicora, Carrie D.; Piehowski, Paul D.; Purvine, Samuel O.; Starrett, Gabriel J.; Goodwin, Lynne A.; Smith, Richard D.; Lipton, Mary S.; Currie, Cameron R.

    2012-09-01

    Herbivores gain access to nutrients stored in plant biomass largely by harnessing the metabolic activities of microbes. Leaf-cutter ants of the genus Atta are a hallmark example; these dominant Neotropical herbivores cultivate symbiotic fungus gardens on massive quantities of fresh plant forage. As the external digestive system of the ants, fungus gardens facilitate the production and sustenance of millions of workers in mature Atta colonies. Here we use metagenomic, and metaproteomic techniques to characterize the bacterial diversity and overall physiological potential of fungus gardens from two species of Atta. Our analysis of over 1.2 Gbp of community metagenomic sequence and three 16S pyrotag libraries reveals that, in addition to harboring the dominant fungal crop, these ecosystems contain abundant populations of Enterobacteriaceae, including the genera Enterobacter, Pantoea, Klebsiella, Citrobacter, and Escherichia. We show that these bacterial communities possess genes commonly associated with lignocellulose degradation, and likely participate in the processing of plant biomass. Additionally, we demonstrate that bacteria in these environments encode a diverse suite of biosynthetic pathways, and that they may enrich the nitrogen-poor forage of the ants with B-vitamins, amino acids, and proteins. These results are consistent with the hypothesis that fungus gardens are highly-specialized fungus-bacteria communities that efficiently convert plant material into usable energy for their ant hosts. Together with recent investigations into the microbial symbionts of vertebrates, our work underscores the importance of microbial communities to the ecology and evolution of herbivorous metazoans.

  2. The fungus gardens of leaf-cutter ants undergo a distinct physiological transition during biomass degradation.

    Science.gov (United States)

    Huang, Eric L; Aylward, Frank O; Kim, Young-Mo; Webb-Robertson, Bobbie-Jo M; Nicora, Carrie D; Hu, Zeping; Metz, Thomas O; Lipton, Mary S; Smith, Richard D; Currie, Cameron R; Burnum-Johnson, Kristin E

    2014-08-01

    Leaf-cutter ants are dominant herbivores in ecosystems throughout the Neotropics that feed on fungus gardens cultivated on fresh foliar biomass. Although recent investigations have shed light on how plant biomass is degraded in fungus gardens, the cycling of nutrients that takes place in these specialized microbial ecosystems is still not well understood. Here, using metabolomic and metaproteomic techniques, we examine the dynamics of nutrient turnover in these gardens. Our results reveal that numerous free amino acids and sugars are depleted throughout the process of biomass degradation, indicating that easily accessible nutrients from plant material are readily consumed by microbes in these ecosystems. Accumulation of cellobiose and lignin derivatives near the end of the degradation process is consistent with previous characterization of lignocellulases produced by the fungal cultivar of the ants. Our results also suggest that ureides may be an important source of nitrogen in fungus gardens, especially during nitrogen-limiting conditions. No free arginine was detected in our metabolomic experiments despite evidence that the host ants cannot produce this amino acid, suggesting that biosynthesis of this metabolite may be tightly regulated in fungus gardens. These results provide new insights into microbial community-level processes that underlie this important ant-fungus symbiosis.

  3. Study on Air-Aided Transport Means of Cutter-Suction Dredger

    Directory of Open Access Journals (Sweden)

    Ting Xiong

    2013-06-01

    Full Text Available This study proves the effectiveness of air-aided transport in reducing pipeline resistance and lengthening transport distance. The adopted experimental apparatus is unique in its chosen pipes (120 mm, transmission mediums (including clean water and slurries concentrated at 10, 20 and 30%, respectively and experiment comparisons between air-aided transport and traditional relay pump transport. Factors such as resistance, transport distance and energy consumption are compared through the data from laboratory experiments, thus proving the evident advantages from air-aided transport. The total energy consumption in air-aided transport is less than that of relay pump, especially within its resistance reducing scope, where slurry flow ranges from 65m3/h to 90 m3/h. It also exists within resistance reducing scope where slurry flow of air-aided transport is less than that of relay pump transport and may reach its limited effective distance. Thus, the findings of this study can provide valuable insight for the optimization design of air-aided transport of cutter-suction dredger.

  4. Does Diatomaceous Earth Control Leaf-Cutter Ants (Hymenoptera: Formicidae) in the Eucalyptus Plantations?

    Science.gov (United States)

    Ferreira-Filho, Pedro J; Wilcken, Carlos F; Neves, Daniela A; Pogetto, Mario H F A D; Carmo, Janaina B; Guerreiro, Julio C; Serrão, José E; Zanuncio, José C

    2015-06-01

    Genus Atta includes some of the most important Formicidae leaf cutter ants which cause extensive damage to the eucalyptus plantations. Atta sexdens rubropilosa Forel, one of the chief pests in Brazilian reforestation, can restrict and reduce forest productivity by its intense and constant leaf-cutting activities on plants at all stages. Therefore, the demand for new products to control A. sexdens rubropilosa indicates the study of the utilization of the dry powder formulation of diatomaceous earth (DE) against this pest in the eucalyptus cultivars. The study was conducted using 120 colonies of A. sexdens rubropilosa in Eucalyptus grandis Hill ex. Maiden x Eucalyptus urophylla Blake (Myrtaceae) (urograndis) stand. The randomized block experimental design was used with six treatments (1, 10, 25, and 50 g/m2 of DE, 6.0 g/m2 sulfluramid bait per square meter of loose soil, and the control) with five replications, each with four colonies of this ant. Diatomaceous earth was applied to the active A. sexdens rubropilosa ant holes, and the sulfluramid bait was applied in bulk in a localized manner. The control efficacy of A. sexdens rubropilosa with DE was low, showing values similar to that of the control, and, for this reason, it cannot be used to control this ant. The bait with sulfluramid showed higher efficacy than those of the other treatments. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  5. Automatic inspection system for dimensional measurements of the saw blade milling cutter

    Directory of Open Access Journals (Sweden)

    Yung-Cheng Wang

    2010-10-01

    Full Text Available The demand for measuring equipments of automatic optical inspection has grown rapidly, because of its benefits of promoted efficiency and higher precision. Instead of manual projection measurements, measurement performance and efficiency can be obviously enhanced by the image measurement system. In this investigation, digital image processing and geometrical measurement principles have been integrated to develop a dynamic measurement system for the dimensional measurements of a saw blade milling cutter. The repeatability of the measurement system has been analyzed and its accuracy has been verified by using commercial 3D image measurement system. The analysis results show that the dimensional precision of 25μm and the angular precision of 0.21° can be realized by the self-developed measurement system. Between the results of the developed system and reference standard system, there are 25μm deviation in dimensional measurement and 0.26° in angular measurement. That measuring performances can meet the industrial requirement and the higher measurement efficiency can be achieved.

  6. 直线电动机在全数控凸轮轴磨床上的应用%Application of Linear Motor in CNC Camshaft Grinder

    Institute of Scientific and Technical Information of China (English)

    邹鹏举; 黄贵刚; 黄辉; 张育平; 黄绍强

    2012-01-01

    介绍了直线电动机在全数控凸轮轴磨床上的应用,说明了直线电动机的工作原理、特点、应用的优越性以及在全数控凸轮轴磨床上的机械装配、系统连接、冷却保护和实际调试的注意事项.将理论设计与实际应用很好地结合起来.实践证明,采用直接驱动的设备,在表面质量、尺寸精度、加工节拍等方面都有一定的突破,基本达到高速、高效、高精的目的.%An Introduction of direct drive and the difference between indirect drive, linear motor in application and the superiority of the linear motor in CNC camshaft grinding machine application was given,a detailed description of the linear motor's working principle,characteristics,application superiority as well as in the CNC camshaft grinder machine assembly, connection,and cooling protection system the actual debugging matters needing attention. The theory and practice are good combination. Practice has proved that adopt direct drive device on the surface quality,dimension precision, processing time and a certain breakthrough,achieved high speed,efficient,and high-precision.

  7. Multifunctional meat grinder control system based on grey forecast%多功能绞肉机智能控制系统

    Institute of Scientific and Technical Information of China (English)

    李兰忖

    2012-01-01

    The multifunctional meat grinder control system is in the center of microcontroller AT89C52 control technology, has realized the organic combination of three kind of functions of boning, grinding and emulsifying. The system pre-selects the program for different degrees emulsifying product by the programming software and hardware circuit, and can automatically adjust each motor's speed to ensure their interlocking requirements by applying the fuzzy PID control technology and stepping motor subdivision technology according to emulsion fineness requirements. So the system responds quickly and runs smooth, and has realized the high accuracy control of the e-mulsifying granularity.%多功能绞肉机控制系统以单片机AT89C52控制技术为核心,实现了出骨、绞肉、乳化3种功能的有机结合.该系统通过硬件电路和编程软件,对不同乳化细度要求的乳化产品有程序预选功能,能够根据乳化细度要求,采用模糊PID控制技术和步进电动机细分控制技术,自动调节各台电动机的速度,并保证它们之间的联锁要求,从而使系统反应快、运行平稳,对乳化粒度实现高精度控制.

  8. 数控凸轮轴磨床砂轮架进给闭式静压导轨的设计%Design of Closed Hydrostatic Guideway for Wheel Rack Feeding of Numerical Controlling Camshaft Grinder

    Institute of Scientific and Technical Information of China (English)

    王洪; 戴瑜兴; 陈永富; 许世雄

    2013-01-01

    针对滚珠丝杆副+V-平导轨存在的油膜厚度不均匀,产生爬行、振纹等现象,提出一种直线电机驱动砂轮架闭式矩形静压导轨的设计方法.分析导轨的受力情况,设计并计算导轨油腔尺寸、供油压力、毛细管节流器长度.将该设计部件运用到某公司生产的YTMK8326-10数控凸轮轴磨床中,加工了2000套油泵凸轮轴.测试结果表明:采用该方法解决了爬行和振纹问题,性能指标与LANDIS数控凸轮轴磨床的相当.%Aiming at the following problems of flat rail of ball screw:uneven thickness,crawling,chattering etc,a design method of closed rectangle hydrostatic guideway for linear motor driving was proposed.The forces of the guideway were analyzed.Size of oil reservoir of guideway,oil supply pressure,and length of restrictor of capillary tube were all computed.The designed component was applied to CNC camshaft grinder YTMK8326-10 produced by a company,and 2000 camshafts of oil pump were machined by this CNC camshaft grinder.The test results show that the proposed method is used to solve problems of both scrawling and chattering,and its performance is equivalent to that of CNC camshaft grinder LANDIS.

  9. Research on Aligning Technique of Cutter Shafting for a 3 500 m^3/h Cutter Suction Dredger%3500m^3绞吸挖泥船绞刀传动轴系对中工艺研究

    Institute of Scientific and Technical Information of China (English)

    饶建荣; 辛小卫

    2012-01-01

    本文主要阐述绞刀传动轴系的安装工艺过程和方法,以保证对中和安装能够顺利进行,并建立此类船舶建造的工艺新标准。%This paper introduces the installation process of a cutter suction dredger to ensure the installation and shafting alignment to progress smoothly and also set up a new standard of such technique.

  10. A unified treatment of some perturbed fixed point iterative methods with an infinite pool of operators

    Science.gov (United States)

    Nikazad, Touraj; Abbasi, Mokhtar

    2017-04-01

    In this paper, we introduce a subclass of strictly quasi-nonexpansive operators which consists of well-known operators as paracontracting operators (e.g., strictly nonexpansive operators, metric projections, Newton and gradient operators), subgradient projections, a useful part of cutter operators, strictly relaxed cutter operators and locally strongly Féjer operators. The members of this subclass, which can be discontinuous, may be employed by fixed point iteration methods; in particular, iterative methods used in convex feasibility problems. The closedness of this subclass, with respect to composition and convex combination of operators, makes it useful and remarkable. Another advantage with members of this subclass is the possibility to adapt them to handle convex constraints. We give convergence result, under mild conditions, for a perturbation resilient iterative method which is based on an infinite pool of operators in this subclass. The perturbation resilient iterative methods are relevant and important for their possible use in the framework of the recently developed superiorization methodology for constrained minimization problems. To assess the convergence result, the class of operators and the assumed conditions, we illustrate some extensions of existence research works and some new results.

  11. Discrete/Finite Element Modelling of Rock Cutting with a TBM Disc Cutter

    Science.gov (United States)

    Labra, Carlos; Rojek, Jerzy; Oñate, Eugenio

    2017-03-01

    This paper presents advanced computer simulation of rock cutting process typical for excavation works in civil engineering. Theoretical formulation of the hybrid discrete/finite element model has been presented. The discrete and finite element methods have been used in different subdomains of a rock sample according to expected material behaviour, the part which is fractured and damaged during cutting is discretized with the discrete elements while the other part is treated as a continuous body and it is modelled using the finite element method. In this way, an optimum model is created, enabling a proper representation of the physical phenomena during cutting and efficient numerical computation. The model has been applied to simulation of the laboratory test of rock cutting with a single TBM (tunnel boring machine) disc cutter. The micromechanical parameters have been determined using the dimensionless relationships between micro- and macroscopic parameters. A number of numerical simulations of the LCM test in the unrelieved and relieved cutting modes have been performed. Numerical results have been compared with available data from in-situ measurements in a real TBM as well as with the theoretical predictions showing quite a good agreement. The numerical model has provided a new insight into the cutting mechanism enabling us to investigate the stress and pressure distribution at the tool-rock interaction. Sensitivity analysis of rock cutting performed for different parameters including disc geometry, cutting velocity, disc penetration and spacing has shown that the presented numerical model is a suitable tool for the design and optimization of rock cutting process.

  12. DIAGNOSIS SHAFT BEARINGS NODE KNIFE CUTTER FOR LOW-FREQUENCY VIBRATION

    Directory of Open Access Journals (Sweden)

    S. T. Antipov

    2015-01-01

    Full Text Available The currently used system of preventive maintenance is not effective enough. Vibration diagnostics is one of the modern methods of non-destructive testing equipment components, allowing to define the appearance of defects in the early stages. The paper identifies the main areas of research, as well as selected research object, selected non-destructive testing method for efficiently determining the actual state of dynamically operating equipment. Is a schematic of vibration sensors. Measuring point vibration parameters were determined experimentally based on the conditions for obtaining the most informative vibroacoustic signal. Determine the behavior of the cutter under which minimizes the occurrence of a wide range of fluctuations that affects the accuracy of the measurements. For vibration analysis method was chosen direct spectral analysis, which involves the detection of repetitive vibrations. Presented graphically vibration spectra and spectra of vibration signals. Analysis of a wide range of vibration spectrum allowed to allocate land on which showed a significant increase in the values of vibration. Processing of the selected portion of the spectrum has led to the conclusion that in the bearing, shock pulses are in contact with each rolling body shell, and as a result, a number of harmonics in the individual frequencies. Was made a comparative analysis of the spectra of working with a defective bearing bearing on the same frequencies and determine the average increase in the values of vibration. Spectral analysis is an effective method to determine not only the extent of the defect and its location, but also allows you to effectively predict its development. The results may be useful for specialists involved in vibration diagnostics, calculation and design of rotary machines.

  13. Fixed mobile convergence handbook

    CERN Document Server

    Ahson, Syed A

    2010-01-01

    From basic concepts to future directions, this handbook provides technical information on all aspects of fixed-mobile convergence (FMC). The book examines such topics as integrated management architecture, business trends and strategic implications for service providers, personal area networks, mobile controlled handover methods, SIP-based session mobility, and supervisory and notification aggregator service. Case studies are used to illustrate technical and systematic implementation of unified and rationalized internet access by fixed-mobile network convergence. The text examines the technolo

  14. Optically fixed photorefractive correlator

    Institute of Scientific and Technical Information of China (English)

    刘友文; 刘立人; 周常河; 徐良瑛

    2002-01-01

    An optically fixed photorefractive correlator is presented, where two-centre non-volatile holographic recording isemployed to write and fix the matched filter in doubly doped LiNbO3 crystals. This correlator shows good correlationcharacteristics and insensitivity to the writing beam during readout. It can be used in cases requiring stability and notrequiring modification for a long period, and it is refreshed optically when new information needs to be registered.

  15. Analysis on Knife Principles and Techniques of CNC Milling Cutter%数控铣削加工对刀原理及对刀技巧探析

    Institute of Scientific and Technical Information of China (English)

    鲁淑叶

    2012-01-01

    Cutter is a major operation and basic skills in NC milling, directly influence the machining precision and efficiency. This paper expounds the purpose and principle of the cutter,and the use of benchmarking tool presetting cutter methods and skills are introduced.%在数控铣削加工中,对刀是一项主要操作和基本技能,对刀精度的高低及效率直接影响零件的加工精度及效率.本文阐述了对刀的目的及原理,并介绍了采用基准工具对刀的方法及技巧.

  16. NaLaF4:Pr3+,Yb3+, an efficient blue to near infra-red quantum cutter

    Directory of Open Access Journals (Sweden)

    A. Guille

    2013-12-01

    Full Text Available In order to reduce the thermalization losses in solar cells, down-conversion of blue photons into near infra-red photons is a promising solution. In the present paper, we analyse the energy transfer processes between Pr3+ and Yb3+ in NaLaF4 and we show that an efficient quantum-cutting process occurs. Nevertheless, we also show that a back transfer from Yb3+ toward the 1G4 level of Pr3+ ion leading to emission beyond 1 μm reduces the potentiality of this material as a quantum cutter for Si solar cells.

  17. Application of Quality Management Tools for Evaluating the Failure Frequency of Cutter-Loader and Plough Mining Systems

    Science.gov (United States)

    Biały, Witold

    2017-06-01

    Failure frequency in the mining process, with a focus on the mining machine, has been presented and illustrated by the example of two coal-mines. Two mining systems have been subjected to analysis: a cutter-loader and a plough system. In order to reduce costs generated by failures, maintenance teams should regularly make sure that the machines are used and operated in a rational and effective way. Such activities will allow downtimes to be reduced, and, in consequence, will increase the effectiveness of a mining plant. The evaluation of mining machines' failure frequency contained in this study has been based on one of the traditional quality management tools - the Pareto chart.

  18. Shrink film patterning by craft cutter: complete plastic chips with high resolution/high-aspect ratio channel.

    Science.gov (United States)

    Taylor, Douglas; Dyer, David; Lew, Valerie; Khine, Michelle

    2010-09-21

    This paper presents a rapid, ultra-low-cost approach to fabricate microfluidic devices using a polyolefin shrink film and a digital craft cutter. The shrinking process (with a 95% reduction in area) results in relatively uniform and consistent microfluidic channels with smooth surfaces, vertical sidewalls, and high aspect ratio channels with lateral resolutions well beyond the tool used to cut them. The thermal bonding of the layers results in strongly bonded devices. Complex microfluidic designs are easily designed on the fly and protein assays are also readily integrated into the device. Full device characterization including channel consistency, optical properties, and bonding strength are assessed in this technical note.

  19. 盾构刀盘支撑法兰密封位磨损修复技术%Repairing of Abrasion on Sealing Position of Shield Cutter Flange

    Institute of Scientific and Technical Information of China (English)

    张洪涛; 郑国良; 刘景华; 王太平

    2012-01-01

    盾构刀盘支撑法兰位于切口环内,主要作用是将刀盘与主驱动连接起来,驱动刀盘的旋转.盾构刀盘支撑通过法兰盘与主驱动齿轮相连,刀盘在旋转过程中连接的密封位极易进入泥砂,长期旋转过程中容易造成密封位的磨损,因此法兰盘在掘进一定距离后必须进行检查、修复.某法兰盘为宽740mm,中心直径2 740mm的圆环,并连接6个牛腿.为防止该法兰盘的变形,采取镶嵌钢环加补焊的修复工艺,达到了法兰盘变形量小、平面精度高的目的.%The cutter flange locates in incision ring of shield which main function is connecting the cutter and main driver to operate the cutter. Because the shield cutter and main driver gears is connected with the flange, so the sediment is easy to enter the sealing position during cutter rotation. The sealing position always abrades during long-term rotating of shield cutter. Thus the flange should be checked and repaired when shield run a certain distance. Some flange connects 6 corbels with 740mm-wideth and 2 740mm-diameter. Repairing technology of inlaying steel ring and welding is adopted to control the deformation and plan accuracy.

  20. Research on the Development of the System Software of CNC grinder machines Based on Windows CE%基于Windows CE的数控磨床系统软件的开发与研究

    Institute of Scientific and Technical Information of China (English)

    刘露; 樊泽明

    2011-01-01

    文章首先对基于ARM的数控磨床系统进行了专门的研究.并以Windows CE作为软件开发平台,运用Embedded Visual C++开发工具设计出系统的人机界面以及整个软件平台.主要论述了WinCE操作系统的定制,文件系统以及编译模块的设计.并且,给出了数控磨床系统的人机界面与软件系统的设计及开发方案.最后.完成整个软件系统的开发.%Researched the system of CNC grinder machines based on ARM,this paper made Windows CE as software platform to develop the human-computer interface and the software platform of the system by making use of Embedded Visual C ++ as develop tool。 Furthermore,it mainly discussed the configuration of WinCE operation system and the design of file system and compiled modules specially. In addition, it provided the design and development program of human-computer interface and the software system of the CNC grinder system and the accomplishment of the development of the software system finally.

  1. Comparison of standard 4-row versus 6-row 3-D linear cutter stapler in creation of gastrointestinal system anastomoses: a prospective randomized trial

    Science.gov (United States)

    Sozutek, Alper; Colak, Tahsin; Dag, Ahmet; Olmez, Tolga

    2012-01-01

    OBJECTIVE: This prospective study was conducted to compare the clinical outcomes of a 6-row 3-D linear cutter with the standard 4-row linear cutter in patients who underwent elective gastrointestinal surgery anastomosis. METHOD: Patients who underwent elective open gastrointestinal surgery that included stapled anastomosis using a linear cutter (Proximate®, Ethicon Endo-Surgery, Cincinnati, OH) between January 2011 and May 2011 were included in the study. The patients were randomly assigned to two groups according to the linear cutter that was used in the surgery: the standard 4-row cutter (the S group) or the new 6-row cutter (the N group). The groups were compared based on the patient demographic data, the laboratory parameters, the preoperative diagnosis, the surgery performed, the operation time, intra- or postoperative complications, the time to oral tolerance and the length of the hospital stay. RESULTS: The S group included 11 male and nine female patients with a mean age of 65±12 (35-84) years, while the N group included 13 male and eight female patients with a mean age of 62±11 (46-79) years (p = 0.448, p = 0.443, respectively). Anastomotic line bleeding was observed in eight (40%) patients in the S group and in one (4.7%) patient in the N group (p = 0.006). Dehiscence of the anastomosis line was observed in two (10%) patients in the S group and none in the N group (p = 0.131). Anastomotic leakage developed in three (15%) patients in the S group and in one (4.7%) patient in the N group (p = 0.269). The mean hospital stay was 12.65±6.1 days in the S group and 9.52±2.9 days in the N group (p = 0.043). CONCLUSION: The 6-row 3-D linear cutter is a safe and easily applied instrument that can be used to create anastomoses in gastrointestinal surgery. The new stapler provides some usage benefits and is also superior to the standard linear cutter with regard to anastomotic line bleeding. PMID:23018300

  2. The possibilities of evaluating the dustiness reduction during operation of longwall cutter-loader; Ocena mozliwosci redukcji zapylenia w czasie pracy kombajnu scianowego

    Energy Technology Data Exchange (ETDEWEB)

    Krauze, K. [Akademia Gorniczo-Hutnicza, Cracow (Poland)

    1995-02-01

    Dust-fighting makes a permanent problem connected with machine mining of hard coal. Reduction of dustiness, especially at present high concentration of mining, gives rise to increased interest of this problem. The article shows the factors and methods allowing correct choice of cutting organs of longwall cutter-loaders. The right choice of organs and spraying system can lead to remarkable reduction of fine fraction of raw coal, thus to generate minimum quantity of dust in place of longwall cutter-loader operation. (author). 11 refs., 8 figs., 2 tabs.

  3. Use of Hub Cutters and the Volume of Sharp Waste and Occurrence of Needle-Stick Injuries during 2011 Mass Immunization Campaigns against Yellow Fever in Ghana: A Cohort Study

    Directory of Open Access Journals (Sweden)

    E Agbenu

    2014-01-01

    Full Text Available Background: Current WHO best infection control practices for injections do not address the use of hub cutters due to insufficient evidence on safety and efficacy. Objective: To assess the impact of the use of hub cutters on 1 the frequency of needle-stick injuries (NSIs and other blood exposures among workers and 2 the volume of sharps waste in a mass vaccination campaign setting. Methods: During yellow fever vaccination in Ghana, we conducted a cohort study on the use of hub cutters. We compared two groups—one group using hub cutters and a control group—for the occurrences of NSIs and the volume of sharp waste produced. Results: In the control arm, vaccinators used 284 482 syringes in 825 vaccination sessions. In the group using hub cutter, vaccinators used 397 079 syringes in 1599 sessions. Among vaccinators, the rate of NSI was not significantly (p=0.14 different between the hub cutter users (0.15/10 000 syringes and the control group (0.04/10 000. Factors such as workload, lack of organization and pressure seemed to have influence the occurrence of NSIs. With all the limitations of the work, the volume of sharp waste per 10 000 syringes was 0.24 m3 in the hub cutter users and 0.41 m3 in the control group—a reduction of 41.2%. Vaccinators found hub cutters easy to use and safe. Use of hub cutter was not associated with increased duration of work. Conclusion: The use of hub cutters did not increase the risk of NSIs. More training is needed to facilitate its implementation in mass campaign setting.

  4. 高速铣刀安全性跨尺度设计方法%Trans-scale Design Method on Safety of High Speed Milling Cutter

    Institute of Scientific and Technical Information of China (English)

    姜彬; 张明慧; 姚贵生; 白锦轩

    2016-01-01

    高速、断续切削载荷作用下的铣刀,其内部不断积聚的能量会引起铣刀原子不可逆运动和宏观结构的改变,高速铣刀安全性具有跨尺度的关联特性。为了提高铣刀安全性,提出一种高速铣刀跨尺度设计方法。采用力连接的方法实现铣刀连续介质力学与分子动力学跨尺度关联,引入熵值法,定量描述铣刀介观安全性。构建铣刀安全性熵值模型,探究铣刀宏介观结构之间的关系,揭示铣刀宏介观安全性对铣刀直径、齿数、齿根结构、刀齿分布、刀片安装前角和铣刀原子群构型参数的响应特性。利用公理设计方法建立高速铣刀安全性跨尺度关联设计模型,并进行铣刀安全性试验验证。分析和试验结果表明,在铣刀高低熵值区内分别发生了属性和程度不同的原子不可逆运动,齿根结构和刀片安装前角对原子群构型具有显著性影响,利用高速铣刀跨尺度设计方法可以提高其安全性,从而为实现高速铣刀高效、可靠、稳定加工提供了保证。%Cutter is under the action of intermittent cutting load in high speed milling, the energy keeps cumulating in the interior of cutter and causes irreversible movement of atomic and the change of macrostructure. Safety of high speed milling cutter presents trans-scale correlation characteristics. In order to improve the safety of cutter, a trans-scale design method on safety of high speed milling cutter is proposed. Trans-scale correlation is achieved by using the method of force connection between continuum mechanics and molecular dynamics. Based on the entropy evaluation method, mesoscopic safety of cutter is quantified. Safety entropy model is proposed, and the model is used to explore relationship between macro and mesoscopic structures of cutter. The response characteristic of cutter safety to its design parameters is revealed, the parameters are diameter, number of teeth

  5. A Failure Analysis Conducted on a Fractured AISI 5160 Steel Blade Which Separated from an Agricultural Rotary Cutter

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Alan A [Metals Research Inc., 101 West Chestnut St., Louisville, Kentucky, 40202 (United States); Storey, Randall J, E-mail: barbalan@bellsouth.net [Deptartment of Industrial Engineering, University of Louisville, Louisville, Kentucky, 40292 (United States)

    2011-07-19

    One of the six blades of an agricultural rotary cutter used for cutting down small trees and bushes broke into two pieces while the blades were rotating. One piece was hurled from the cutter and struck a young farmer, who had been operating the machine, causing a near fatal leg injury. In the ensuing litigation against the manufacturers and marketer of the machine each litigant retained a metallurgist and other experts. The metallurgists jointly directed laboratory work on the broken blade conducted at an independent laboratory according to a protocol which they developed and which was approved by the court. As a result of the laboratory work the present authors, working for the Plaintiffs, concluded that failure of the blade occurred because it contained quench cracks introduced when it was manufactured. The Defendants' metallurgists concluded that the blade had been misassembled onto the machine and, as a result, had failed by fatigue. Eventually, the case was set for a jury trial in a Circuit Court in rural Kentucky. The jury found for the Plaintiffs and awarded them $5.9 million in damages. Part of this judgement was later reversed by the Kentucky Court of Appeals and the case was then settled without a second trial under terms which were not revealed.

  6. A metabolic pathway assembled by enzyme selection may support herbivory of leaf-cutter ants on plant starch.

    Science.gov (United States)

    Bacci, Maurício; Bueno, Odair Correa; Rodrigues, André; Pagnocca, Fernando Carlos; Somera, Alexandre Favarin; Silva, Aline

    2013-05-01

    Mutualistic associations shape the evolution in different organism groups. The association between the leaf-cutter ant Atta sexdens and the basidiomycete fungus Leucoagaricus gongylophorus has enabled them to degrade starch from plant material generating glucose, which is a major food source for both mutualists. Starch degradation is promoted by enzymes contained in the fecal fluid that ants deposit on the fungus culture in cut leaves inside the nests. To understand the dynamics of starch degradation in ant nests, we purified and characterized starch degrading enzymes from the ant fecal fluid and from laboratory cultures of L. gongylophorus and found that the ants intestine positively selects fungal α-amylase and a maltase likely produced by the ants, as a negative selection is imposed to fungal maltase and ant α-amylases. Selected enzymes are more resistant to catabolic repression by glucose and proposed to structure a metabolic pathway in which the fungal α-amylase initiates starch catalysis to generate byproducts which are sequentially degraded by the maltase to produce glucose. The pathway is responsible for effective degradation of starch and proposed to represent a major evolutionary innovation enabling efficient starch assimilation from plant material by leaf-cutters.

  7. Simulation of crack coalescence mechanism underneath single and double disc cutters by higher order displacement discontinuity method

    Institute of Scientific and Technical Information of China (English)

    Mohammad Fatehi Marji

    2015-01-01

    The present research is focused on the numerical crack coalescence analysis of the micro-cracks and cracks produced during the cutting action of TBM disc cutters. The linear elastic fracture mechanics (LEFM) concepts and the maximum tangential stress criterion are used to investigate the micro crack propagation and its direction underneath the excavating discs. A higher order displacement discontinuity method with quadratic displacement discontinuity elements is used to estimate the stress intensity factors near the crack tips. Rock cutting mechanisms under single and double type discs are simulated by the proposed numerical method. The main purposes of the present modeling are to simulate the chip formation process of indented rocks by single and double discs. The effects of specific disc parameters (except speed) on the thrust force Ft, the rolling force Fr, and the specific energy ES are investigated. It has been shown that the specific energy (energy required to cut through a unit volume of rock) of the double disc is less than that of the single disc. Crack propagation in rocks under disc cutters is numerically modeled and the optimum ratio of disc spacing S to penetration depth Pd (i.e. S/Pd ratio) of about 10 is obtained, which is in good agreement with the theoretical and experimental results cited in the literature.

  8. On the bi-dimensional variational decomposition applied to nonstationary vibration signals for rolling bearing crack detection in coal cutters

    Science.gov (United States)

    Jiang, Yu; Li, Zhixiong; Zhang, Chao; Hu, Chao; Peng, Z.

    2016-06-01

    This work aims to detect rolling bearing cracks using a variational approach. An original method that appropriately incorporates bi-dimensional variational mode decomposition (BVMD) into discriminant diffusion maps (DDM) is proposed to analyze the nonstationary vibration signals recorded from the cracked rolling bearings in coal cutters. The advantage of this variational decomposition based diffusion map (VDDM) method in comparison to the current DDM is that the intrinsic vibration mode of the crack can be filtered into a limited bandwidth in the frequency domain with an estimated central frequency, thus discarding the interference signal components in the vibration signals and significantly improving the crack detection performance. In addition, the VDDM is able to simultaneously process two-channel sensor signals to reduce information leakage. Experimental validation using rolling bearing crack vibration signals demonstrates that the VDDM separated the raw signals into four intrinsic modes, including one roller vibration mode, one roller cage vibration mode, one inner race vibration mode, and one outer race vibration mode. Hence, reliable fault features were extracted from the outer race vibration mode, and satisfactory crack identification performance was achieved. The comparison between the proposed VDDM and existing approaches indicated that the VDDM method was more efficient and reliable for crack detection in coal cutter rolling bearings. As an effective catalyst for rolling bearing crack detection, this newly proposed method is useful for practical applications.

  9. Leaf-cutter ant fungus gardens are biphasic mixed microbial bioreactors that convert plant biomass to polyols with biotechnological applications.

    Science.gov (United States)

    Somera, Alexandre F; Lima, Adriel M; Dos Santos-Neto, Álvaro J; Lanças, Fernando M; Bacci, Maurício

    2015-07-01

    Leaf-cutter ants use plant matter to culture the obligate mutualistic basidiomycete Leucoagaricus gongylophorus. This fungus mediates ant nutrition on plant resources. Furthermore, other microbes living in the fungus garden might also contribute to plant digestion. The fungus garden comprises a young sector with recently incorporated leaf fragments and an old sector with partially digested plant matter. Here, we show that the young and old sectors of the grass-cutter Atta bisphaerica fungus garden operate as a biphasic solid-state mixed fermenting system. An initial plant digestion phase occurred in the young sector in the fungus garden periphery, with prevailing hemicellulose and starch degradation into arabinose, mannose, xylose, and glucose. These products support fast microbial growth but were mostly converted into four polyols. Three polyols, mannitol, arabitol, and inositol, were secreted by L. gongylophorus, and a fourth polyol, sorbitol, was likely secreted by another, unidentified, microbe. A second plant digestion phase occurred in the old sector, located in the fungus garden core, comprising stocks of microbial biomass growing slowly on monosaccharides and polyols. This biphasic operation was efficient in mediating symbiotic nutrition on plant matter: the microbes, accounting for 4% of the fungus garden biomass, converted plant matter biomass into monosaccharides and polyols, which were completely consumed by the resident ants and microbes. However, when consumption was inhibited through laboratory manipulation, most of the plant polysaccharides were degraded, products rapidly accumulated, and yields could be preferentially switched between polyols and monosaccharides. This feature might be useful in biotechnology.

  10. The role of leaf cutter ants on soil organic carbon dynamics in a wet tropical forest

    Science.gov (United States)

    Schwendenmann, L.; Meredyth-Young, M.; Dierick, D.; Allen, M. F.; Harmon, T. C.; Oberbauer, S. F.; Rundel, P.; Trahan, N. A.; Zelikova, T. J.

    2016-12-01

    Tropical forest ecosystems play an important role in the global carbon (C) cycle. Neotropical forests are significantly influenced by leaf cutter ants (LCA) which are the most important herbivore in these systems. LCA cut fresh leaves and bring large amounts of plant biomass into their nests to grow their fungus gardens. The excavation and continual maintenance of their large nests modifies soil characteristics and biogeochemistry with direct and indirect impacts on soil organic carbon (SOC) dynamics. The aim of this study was to quantify the effects of LCA (Atta cephalotes) on soil C mineralization, carbon degrading enzymes (β-glucosidase and α-glucosidase), and labile soil C (hot water extractable carbon) across a 1 m soil depth profile and comparing between two different soils (residual and alluvial) and forest types (primary and secondary) in a wet tropical rainforest in Costa Rica. We hypothesized that C mineralization rates will be higher inside LCA nests due to continual input of fresh organic matter, as evidenced by higher microbial biomass and carbon degrading enzymes. Similarly, we expected more labile C inside nests. All soil C parameters were highly variable among sites and between nests and controls. Carbon mineralization rates ranged from 0.02 to 0.2 µmol C h-1 g soil-1 during the initial decay phase which lasted approximately 6 days during soil incubation. The highest respiration rates were measured in the top 20 cm of the primary forest residual soil. Contrary to our expectations, C mineralization rates were higher in control soils, where C degrading enzymes were in higher concentrations (around 250 µmol). The labile soil C concentrations were variable across sites (2-25 mg C g soil-1) and higher in the upper soil profiles, but no significant differences were found between controls and nests. Our results indicate greater heterogeneity inside the nests than previously expected. We explain our findings in terms of the removal of leaf and organic

  11. Fixing Dataset Search

    Science.gov (United States)

    Lynnes, Chris

    2014-01-01

    Three current search engines are queried for ozone data at the GES DISC. The results range from sub-optimal to counter-intuitive. We propose a method to fix dataset search by implementing a robust relevancy ranking scheme. The relevancy ranking scheme is based on several heuristics culled from more than 20 years of helping users select datasets.

  12. 平底刀最优刀轴矢量规划算法%Optimal Tool Orientation for Five-axis Flat-end Cutter Machining

    Institute of Scientific and Technical Information of China (English)

    章永年; 赵东标; 陆永华; 刘凯

    2012-01-01

    While determining the optimal tool orientation for five-axis flat-end cutter machining, most algorithms only pursue the maximum material removal rate without taking into account other factors, such as the machining quality and the smoothness between adjacent tool orientations. The metrics of tool orientation considering all above are established. Aiming at the minimal weighted metrics, an optimization model with several springs is established, and the problem of rinding optimal tool orientation is treated as the mechanical equilibrium problem. The fixed point at Gaussian map will converge to locus of the optimal tool orientation. The simulation results show that the weight of SE and Dp influences the machining efficiency and quality, respectively, and the movement smoothness is affected by Av and Dm weights. The optimal tool orientations with high efficiency, stable machining and smooth movement can be determined using an appropriate group of weights.%在进行自由曲面平底刀五轴数控加工刀轴矢量规划时,现有算法多以材料去除率最大作为优化目标,然而加工效率最高的刀轴矢量不一定是刀具最优姿态,还需要综合考虑加工质量、刀轴光顺等因素.从这几个方面建立单个刀轴矢量和相邻刀轴矢量光顺性的度量指标,并以归一化度量指标加权和最小作为优化目标建立刀轴矢量优化模型,经理论分析将多目标规划问题转化为力学平衡问题,弹簧模型中高斯球面上运动节点的平衡位置就是最优刀轴矢量.仿真结果表明SE权因子影响加工效率,DW、DM权因子影响机床运动平稳性,DF权因子影响切削条件,选择合适的权因子可以获得材料去除率大、加工效率高以及在工件坐标系、机床坐标系和进给坐标系下光顺的刀轴矢量.

  13. Design of Milling Cutter of Frictional Hard Alloy Mechanical Clamped Grooves%可磨式机夹硬质合金铣槽刀的设计

    Institute of Scientific and Technical Information of China (English)

    吴潮汕

    2011-01-01

    The problems of production in mechanical processing was prescribed because of cutter factors, such as pieces with grooves when that were processing with normal cutter, which maybe occur the problems as low production efficiency, poor product quality, vulnerable cutter, hard respiring cutter and serious waste. But the design and making of new type of frictional hard alloy mechanical clamped grooves have soled the difficult problem of processing. After milling the cutter tooth, the cutter tooth can be took off for milling knife edge, collate knifepoint of knife edge with own made tool setting gauge, and process cutter edge installed on tool shank again. The new type of groove knife can be applied in normal milling lather or CNC milling lather, which can milling grooves, planes and head faces, and can set tool outside machine, reduce occupation time with the characteristics of convenient operation, simple structure, high efficiency, low cost. It is proved that it can meet the requirements of processing.%主要阐述了机械加工中刀具因素给生产带来的困扰,如经常会遇到加工一些带沟槽的零件,使用常规刀具加工零件,生产效率低、产品质量难保证、刀具易损坏且修复困难、浪费严重.而新型可磨式机夹硬质合金铣槽刀的设计与制作,解决了加工中的难题.当刀齿磨后,可将刀齿取下修磨刀刃,用自制的对刀仪校对刀齿刀尖,重新把刀齿安装在刀柄上加工.这种新型铣沟槽刀可在普通铣床或数控铣床上使用,可铣沟槽、平面和端面,可机外对刀,减少占机时间,操作简便,结构简单,工效高,成本低.实践证明,新型可磨式机夹硬质合金铣槽刀能满足加工需求.

  14. 盾构切刀切削软岩特性研究%Cutting Performance of Shield Cutters in Soft Rock

    Institute of Scientific and Technical Information of China (English)

    张旭辉; 谭青; 夏毅敏; 蔡小华; 曾桂英; 张佳

    2015-01-01

    Based on the rational simplification of the cutting process of shield cutters in soft rock, this paper establishes a 2D numerical model using the particle discrete element method; analyzes a dynamic cutting process;and studies the influence of the rake angle, cutting depth and rock joint on the rock-breaking performance of shield cutters. The results show that cutting the soft rock is a process of "extruding and then tensioning." The force application point of a cutter is gradually shifted from the tip of the cutter to the front edge of the cutter, and then back to the tip of the cutter with variations of the cutting stroke, which is consistent with the change of the cutter force. With the increase of the cutter's rake angle and cutting depth, the broken rock block increases while the specific energy consumption decreases. The rock-breaking modes of the cutter are different under different joint dip angles, and because of more easily forming the broken rock block the rock-breaking efficiency is higher under a joint angle of less than 90° than a joint angle of more than or equal to 90° . The experiments show that the actual process of rock breaking and the force applied on the cutter agree well with those determined via numerical simulation.%文章在对盾构切刀切削软岩动态过程进行合理简化的基础上,从软岩细观角度出发,采用颗粒离散元法建立了切刀切削软岩的二维数值模型,对切刀切削动态过程进行了分析,并研究了切刀前角、切深以及节理对切刀切削特性的影响. 研究结果表明:切刀切削软岩是一个先挤压后张拉的过程,切刀着力点随切削行程的改变由刀尖逐渐向刀前刃上方转移,然后再回到刀尖,与切削力变化规律一致;破碎块随切刀前角和切深的增加呈增大趋势;比能耗随切刀前角和切深的增加呈减小趋势;节理倾角不同切刀破岩呈不同破坏方式,节理倾角小于90°时,更容易形成破碎块,破岩效

  15. Fixed textile shutters

    Directory of Open Access Journals (Sweden)

    K.A. Chernova

    2010-06-01

    Full Text Available One of the main socio-economic problems in Russia is the high cost and the poor condition of housing.Such goals as cost reduction, reducing installation time and increasing the service life of structures are accomplishing by creating new technologies of erecting buildings and developing ways ofquickconstruction, using different types of fixed formwork. One of themis textstone.Textstone is an artificial construction stone, containing on the outer surface the reinforcing fine-mesh shell with multifunctional properties, formed by the interwoven threads of a vigorous fixed formwork textile material (basalt, linen, silica and other glass yarns adhered by binding material. The innovative construction technology of production and installation of a new generation of textstone buildings has been registered as a brand TextStone. The fundamental difference between texstone and reinforced concrete and all known building materials is that the whole outer surface of solidified light binders is protected by strong, vigorous and fixed formwork made from inexpensive textile materials. Manufacturing textile shells allows using it as an internal finishing material, reducing or eliminating the cost of finishing work.The use of fixed textile construction shutters during the construction of buildings has obvious technical, economic, operational, sanitary and environmental benefits: short construction time (from 3 to 10 days, compact packaging and light weight of fabric shells, high fire resistance, frost resistance, ease of engineering services installation in the hollow communicating shells; minimal amount of finishing, roofing, heat and noise insulation works. Texstone is a durable solid monolithic construction that provides high viability and earthquakes, hurricanes wind, solar sultriness and frost resistance. Material complies with all sanitary and environmental requirements. Due to such physical, mechanical, operational, sanitary and ecological characteristics

  16. Fixed Sagittal Plane Imbalance

    OpenAIRE

    Savage, Jason W.; Patel, Alpesh A.

    2014-01-01

    Study Design Literature review. Objective To discuss the evaluation and management of fixed sagittal plane imbalance. Methods A comprehensive literature review was performed on the preoperative evaluation of patients with sagittal plane malalignment, as well as the surgical strategies to address sagittal plane deformity. Results Sagittal plane imbalance is often caused by de novo scoliosis or iatrogenic flat back deformity. Understanding the etiology and magnitude of sagittal malalignment is ...

  17. Numerical Simulation on Sliding Abrasion when TBM Disc Cutter Breaking the Rock%TBM 滚刀破岩时滑移量的数值模拟研究

    Institute of Scientific and Technical Information of China (English)

    苏翠侠

    2015-01-01

    With large consumption and high cost of disc cutter which used for TBM rock breaking,the irrational cutter changing will cause an adverse impact on duration,construction cost and TBM.So it is of great importance to study disc cutter wear characteristics and predict cutter wear,and the force of disc cutter and sliding abrasion are vital to the predic-tions of cutter wear mechanism and its abrasion.A finite element model is built to simulate the process of rock breaking by ABAQUS in this paper.Cutter sliding and the force distribution of cutter are obtained and the influence of cutter penetration and friction coefficient to cutter sliding are also studied based on the established model numerically.The results indicate that sliding abrasion is proportional to cutter penetration and inversely proportional to friction coefficient.The results may be utilized to the abrasion prediction of TBMdisc cutter.%TBM破岩用的盘形滚刀消耗量大且价格昂贵,不合理的换刀会对工期、施工成本以及 TBM本身造成不利影响,研究盘形滚刀的磨损特性以及预测滚刀磨损具有重要意义。滚刀破岩时其受力情况及滑移量对滚刀磨损机理及磨损量的预测至关重要,本文利用软件 ABAQUS 建立了盘形滚刀破岩过程的有限元模型,研究了滚刀滑移现象以及滚刀受力分布情况。定量地分析了滚刀贯入度以及滚刀与岩石间的摩擦系数对滚刀滑移的影响。结果表明:滚刀破岩时的滑移量与贯入度成正比,与摩擦系数成反比。所得结果可以为滚刀磨损量的预测提供参考。

  18. 高压蒸汽灭菌法对两种末端切断钳影响的比较%Effect of high-pressure steam sterilization on two kinds of orthodontic distal end cutters

    Institute of Scientific and Technical Information of China (English)

    王婧; 曹帅; 王璞; 张凯亮; 曹宝成

    2013-01-01

    背景:虽然蒸汽灭菌法是口腔临床常用的一种消毒方法,但其是否会对消毒器械产生更明显的影响学术界一直存在着争议。  目的:对比分析高压蒸汽灭菌后两种常用正畸用末端切断钳剪切力值及腐蚀程度的变化,以明确高压蒸汽灭菌法对两种品牌末端切断钳的影响。  方法:取天天、3M牌末端切断钳各15把,均随机分为3组,分别进行高压蒸汽灭菌,高压蒸汽灭菌联合口外剪切,高压蒸汽灭菌联合口内剪切。测量经0,20,40,60次消毒后末端切断钳的剪切力,拍摄金相片并对两种切断钳钳喙进行X射线能谱分析。  结果与结论:随着消毒次数增加,6组切断钳的剪切力值均随之增大,天天末端切断钳3组剪切力的增大程度明显大于对应的3M末端切断钳3组(P OBJECTIVE:To investigate the effect of autoclave on two kinds of orthodontic distal end cutters by comparing shearing force and corrosion after sterilization. METHODS:Tiantian (n=15) and 3M (n=15) distal end cutters commonly used in orthodontic treatment were chosen for testing and divided into three groups, respectively. Three groups for each kind of cutter were treated with high-pressure steam sterilization, steam sterilization+extraoral shear, and steam sterilization+intraoral shear, respectively. The shearing force and metal ography of the distal end cutters were recorded after 0, 20, 40, and 60 cycles of sterilization. An energy dispersive spectrometer was used to scan the surfaces of the working edges of the distal end cutters after 60 cycles. RESULTS AND CONCLUSION:It was found that with an increase in the number of sterilization cycles, the shear force and extent of corrosion increased in al six groups of distal end cutters, but the situation was worse for Tiantian cutters than for 3M cutters. It was found that the difference of shear force between the Tiantian autoclave group and 3M autoclave

  19. 锤片式粉碎机在酒厂曲块粉碎中的应用%The Application of the Type of Hammer Piece Grinder for Rhizopus Brick Smash in Distillery

    Institute of Scientific and Technical Information of China (English)

    付捷; 崔勇; 罗钢; 王瑛

    2011-01-01

    通过锤片式粉碎机在酒厂曲块粉碎中的试验分析,提出了曲块粉碎采用双级粉碎流程、降低锤片线速度、增大筛孔直径、减少装机功率、提高风机转速等措施,取得了较好效果.%Through the experimental analysis of the type of hammer piece grinder for rhizopus brick smash in distillery, This article proposed rhizopus brick smash used the two-stage smashing flow, reduced the hammer piece link speed, increased the mesh diameter, reduced installing equipment power, by enhancing the air blower rotational speed and so on. The good effect has been obtained.

  20. 大型龙门导轨磨床IPMP变频伺服液压系统设计%Design of the IPMP Frequency Servo Hydraulic System for Large Size Gantry Slideway Grinder

    Institute of Scientific and Technical Information of China (English)

    郑涛青; 黎保新; 刘昌民

    2014-01-01

    The design about an energy saving and environmental protection type large gantry guideway grinder IPMP frequency servo hydraulic system and the energy consumption calculation were introduced.The “quantitative pump and frequency servo motor”was used to replace traditional “quantitative pump and proportional valve”system,through the inverter to control the pump speed, through pressure sensor and rotary encoder to feedback the pressure and flow signal,closed-loop control was realized,pressure and flow can be output by required,no extra power loss.4 groups of 22 kW IPMP pumping station design can meet requirements of overload, wide speed range,low power of the large gantry guideway grinder.%介绍一种节能环保的大型龙门导轨磨床IPMP变频伺服液压系统的设计及能耗计算。利用“定量泵+变频伺服电机”替代传统的“定量泵+比例调速阀”系统,通过变频器控制油泵的转速,用压力传感器和旋转编码器对压力及流量信号进行反馈,实现闭环控制,压力、流量可以按需输出,没有多余的功率被损耗。4组22 kW IPMP泵站设计可以满足大型龙门导轨磨床超重载、宽调速、低能耗要求。

  1. The genome sequence of the leaf-cutter ant Atta cephalotes reveals insights into its obligate symbiotic lifestyle.

    Directory of Open Access Journals (Sweden)

    Garret Suen

    Full Text Available Leaf-cutter ants are one of the most important herbivorous insects in the Neotropics, harvesting vast quantities of fresh leaf material. The ants use leaves to cultivate a fungus that serves as the colony's primary food source. This obligate ant-fungus mutualism is one of the few occurrences of farming by non-humans and likely facilitated the formation of their massive colonies. Mature leaf-cutter ant colonies contain millions of workers ranging in size from small garden tenders to large soldiers, resulting in one of the most complex polymorphic caste systems within ants. To begin uncovering the genomic underpinnings of this system, we sequenced the genome of Atta cephalotes using 454 pyrosequencing. One prediction from this ant's lifestyle is that it has undergone genetic modifications that reflect its obligate dependence on the fungus for nutrients. Analysis of this genome sequence is consistent with this hypothesis, as we find evidence for reductions in genes related to nutrient acquisition. These include extensive reductions in serine proteases (which are likely unnecessary because proteolysis is not a primary mechanism used to process nutrients obtained from the fungus, a loss of genes involved in arginine biosynthesis (suggesting that this amino acid is obtained from the fungus, and the absence of a hexamerin (which sequesters amino acids during larval development in other insects. Following recent reports of genome sequences from other insects that engage in symbioses with beneficial microbes, the A. cephalotes genome provides new insights into the symbiotic lifestyle of this ant and advances our understanding of host-microbe symbioses.

  2. Fixed-Term Homotopy

    Directory of Open Access Journals (Sweden)

    Hector Vazquez-Leal

    2013-01-01

    Full Text Available A new tool for the solution of nonlinear differential equations is presented. The Fixed-Term Homotopy (FTH delivers a high precision representation of the nonlinear differential equation using only a few linear algebraic terms. In addition to this tool, a procedure based on Laplace-Padé to deal with the truncate power series resulting from the FTH method is also proposed. In order to assess the benefits of this proposal, two nonlinear problems are solved and compared against other semianalytic methods. The obtained results show that FTH is a power tool capable of generating highly accurate solutions compared with other methods of literature.

  3. Fixed and Sunk Costs Revisited.

    Science.gov (United States)

    Wang, X. Henry; Yang, Bill Z.

    2001-01-01

    Attempts to clarify the concepts of, and the link between, fixed costs and sunk costs. Argues that the root of confusion is the inconsistency in defining the term fixed costs. Consistently defines fixed and sunk costs, and describes how instructors must teach under these definitions. (RLH)

  4. Fixed sagittal plane imbalance.

    Science.gov (United States)

    Savage, Jason W; Patel, Alpesh A

    2014-12-01

    Study Design Literature review. Objective To discuss the evaluation and management of fixed sagittal plane imbalance. Methods A comprehensive literature review was performed on the preoperative evaluation of patients with sagittal plane malalignment, as well as the surgical strategies to address sagittal plane deformity. Results Sagittal plane imbalance is often caused by de novo scoliosis or iatrogenic flat back deformity. Understanding the etiology and magnitude of sagittal malalignment is crucial in realignment planning. Objective parameters have been developed to guide surgeons in determining how much correction is needed to achieve favorable outcomes. Currently, the goals of surgery are to restore a sagittal vertical axis Sagittal plane malalignment is an increasingly recognized cause of pain and disability. Treatment of sagittal plane imbalance varies according to the etiology, location, and severity of the deformity. Fixed sagittal malalignment often requires complex reconstructive procedures that include osteotomy correction. Reestablishing harmonious spinopelvic alignment is associated with significant improvement in health-related quality-of-life outcome measures and patient satisfaction.

  5. Fixed Access Network Sharing

    Science.gov (United States)

    Cornaglia, Bruno; Young, Gavin; Marchetta, Antonio

    2015-12-01

    Fixed broadband network deployments are moving inexorably to the use of Next Generation Access (NGA) technologies and architectures. These NGA deployments involve building fiber infrastructure increasingly closer to the customer in order to increase the proportion of fiber on the customer's access connection (Fibre-To-The-Home/Building/Door/Cabinet… i.e. FTTx). This increases the speed of services that can be sold and will be increasingly required to meet the demands of new generations of video services as we evolve from HDTV to "Ultra-HD TV" with 4k and 8k lines of video resolution. However, building fiber access networks is a costly endeavor. It requires significant capital in order to cover any significant geographic coverage. Hence many companies are forming partnerships and joint-ventures in order to share the NGA network construction costs. One form of such a partnership involves two companies agreeing to each build to cover a certain geographic area and then "cross-selling" NGA products to each other in order to access customers within their partner's footprint (NGA coverage area). This is tantamount to a bi-lateral wholesale partnership. The concept of Fixed Access Network Sharing (FANS) is to address the possibility of sharing infrastructure with a high degree of flexibility for all network operators involved. By providing greater configuration control over the NGA network infrastructure, the service provider has a greater ability to define the network and hence to define their product capabilities at the active layer. This gives the service provider partners greater product development autonomy plus the ability to differentiate from each other at the active network layer.

  6. Vibration analysis of reciprocating cutter based on Fourier series%基于傅里叶级数的往复式切割器振动分析

    Institute of Scientific and Technical Information of China (English)

    严帅

    2013-01-01

    本文对曲柄连杆往复式切割器工作特性进行了分析,利用傅里叶级数将切割器周期激励分解为简谐收敛级数,以特征值为插值结点对傅里叶级数的待定系数进行了求解,并利用叠加原理求出切割器振动系统的稳态响应。%This paper analyzed the characteristics of the crank and connecting rod reciprocating cutter, decomposed the cutter periodic excitation into the harmonic convergenc series using the Fourier series, undetermined coefficients of Fourier series are solved with the eigenvalues for the interpolation nodes, and by using the principle of superposition to calculate the steady-state vibration response of system.

  7. Desin and application of a new type of boring cutter head%一种新型镗刀头的设计与应用

    Institute of Scientific and Technical Information of China (English)

    林景凡

    2013-01-01

    Basis of comparison in two kinds of boring cutter structure and processing characteristics.The machine clamp in large diameter deep hole boring processing technology of single blade. Can replace the commonly used strong rough boring, boring, floating cutter honing processes three, can make the work efficiency is improved by more than 3 times.%在两种镗刀结构和加工特点比较的基础上,介绍了机夹单刃镗刀加工大直径深孔工艺。可取代通常使用的强力粗镗、浮动刀精镗、珩磨三道工序,可使工效提高3倍以上。

  8. Design of HSM cutters management system based on DNC%基于DNC的高速切削刀具库系统的研究

    Institute of Scientific and Technical Information of China (English)

    刘丽娟; 吕明; 武文革

    2013-01-01

    HSM cutters management system is established to realize the accurate research and management. Providing the most optimal data for cutters choice, scheduling, management and fault diagnosis in the whole life cycle of HSM, shorting the producing life, prolonging the cutters life, providing benefit guide for HSM. The system has strong realistic feasibility.%以实现高速切削刀具信息的精确检索和管理为目标,建立了高速切削刀具管理系统,为高速切削生产全生命周期中对于刀具的选择、调度、管理以及故障诊断等方面提供最优化的数据,缩短生产周期,延长刀具寿命,为高速切削生产提供有益的指导作用.该系统实现具有较强的现实可行性.

  9. 基于无瞬心包络法的偏心螺杆成型铣刀研究%Study of Formed Milling Cutter for Processing Eccentric Screw Based on Non-Instantaneous Envelope Method

    Institute of Scientific and Technical Information of China (English)

    李云; 范晋伟; 陈东菊; 王晓峰; 刘勇军

    2012-01-01

    根据偏心螺杆的形状和特征参数,建立了偏心螺杆的螺旋曲面方程;基于无瞬心包络法,从成型铣刀与偏心螺杆的相对运动关系出发,依据成型铣刀与螺杆的啮合条件,建立其接触线方程.由接触线围绕铣刀轴线回转形成回转面的轴向截形,推导出铣刀刀刃的廓形方程.进一步分析了成型铣刀用钝重磨后引起加工误差的原因,以阿基米德螺线为基础建立铣刀的齿背曲线方程,得到具有恒定后角的铣刀廓形方程.仿真结果表明,成型铣刀的廓形与偏心螺杆螺旋曲面吻合良好,设计的成型铣刀廓形方程符合加工要求.%The design theory and method of formed milling cutter for eccentric screw is presented. Through analyzing the shape and characteristic parameters of eccentric screw, the spiral surface equation of eccentric screw was established. Considering the relative motion and the meshing conditions between formed milling cutter and eccentric screw, the contact line equation was established based on non-instantaneous envelope method. Further, from the cross-section shape of the rotary surface formed by the contact line around the axis of cutter, the profile equation of formed milling cutter was deduced. By analyzing the causes of processing errors after wear of formed milling cutter, the tooth back curve equation was achieved in accordance with spiral of Archimedes and got the profile equation of formed milling cutter with constant back edge was gotten. Finally, the interference for profile equation of formed milling cutter was checked. Simulation shows that the profile of formed milling cutter coincides with the spiral surface of eccentric screw and the designed profile equation of formed milling cutter conforms to the requirements of the processing. This work provides a theoretical foundation for the design and manufacture of formed milling cutter.

  10. 木薯种植机种茎切断装置的设计%Design of Cassava Stalk Cutter for Cassava Planting Machine

    Institute of Scientific and Technical Information of China (English)

    崔振德; 邓干然; 李国杰; 刘智强; 郑爽; 李玲

    2017-01-01

    机械化种植技术能够大大提高木薯种植效率,降低种植成本,是木薯田间生产大势所趋,而国内木薯种植设备研究起步晚,尚存在诸多问题。为此,结合木薯种植农艺要求及木薯种茎特性,针对木薯种植机种茎切断装置设计中存在的问题,进行了有关切秆装置设计的理论研究,分别对外形尺寸、整体结构、切秆刀辊、刀片及护盖等进行了分析与设计。试验表明:所设计的木薯种茎切断装置能够稳定切断木薯秆,拖拉机行驶速度约1.2m/s 时,作业稳定性高,无故障作业面积可达40hm2以上。%Mechanized planting techniques can greatly improve the efficiency of cassava planting, reduce the cost, it's development trend of cassava field production. However, domestic research on cassava planting machine is not enough, there are still many problems. Firstly, studied the problems of cassava stalk cutter occurred when planting machines had worked in fields. Then theoretical studies on designing of cassava stalk cutter was did. At last the overall structure of cut-ter, cutter roller, blade and cover were analyzed and designed respectively referencing agronomy planting requirements and cassava stalk biological and physical characteristics. Tests shows that this type cassava stalk cutting device worked stably. When a cassava planting machine with designed cutter driven by a tractor moving about 1. 2m/s, it has the best performance. It worked 600 acres with trouble-free operation.

  11. Natural enemies of Atta vollenweideri (Hymenoptera: Formicidae) leaf-cutter ants negatively affected by synthetic pesticides, chlorpyrifos and fipronil.

    Science.gov (United States)

    Guillade, Andrea C; Folgarait, Patricia J

    2014-02-01

    In southern South America, Ada vollenweideri Forel (Hymenoptera: Formicidae) is a significant pest of several crops and forestry, also considered to reduce the carrying capacity of pastures. The most usual control method used in Latin America is the application of synthetic pesticides, mainly chlorpyrifos and fipronil. However, no studies have assessed the effects of these agrochemicals on natural enemies of ants. We aimed to evaluate the efficiency of these pesticides on leaf-cutter ants' control and to test their effect on phorid fly parasitoids. Chlorpyrifos failed to exert complete control over ant colonies in the field and was gravely detrimental to specific parasitoids, reducing their percentage of parasitism, pupal survivorship, and adult longevity. Fipronil, however, exerted complete control over the treated colonies. Laboratory tests using both pesticides, either on ants from foraging trails or on pupariae, showed that chlorpyrifos and fipronil decreased larval and pupal survivorship, as well as adult longevity of parasitoids, in comparison to controls. In conclusion, these pesticides will likely affect parasitoids with regard to their reproductive capacity, leading to the decreased levels of natural parasitism observed in the field after treatments. We discuss why neither pesticide should be taken into account for integrated pest management programs.

  12. Perancangan Sistem Permesinan Dan Sistem Penggerak Pada Auger Cutter Suction Dredger (ACSD Sebagai Metode Pengerukan Di Waduk

    Directory of Open Access Journals (Sweden)

    Andri Prasetyo

    2014-03-01

    Full Text Available Auger Cutter Suction Dredger (ACSD adalah salah salah satu jenis kapal keruk dari beberapa jenis kapal keruk yang ada. Sistem permesinan yang beroperasi pun lebih bervariatif karena selain kapal harus bergerak (moving kapal juga melakukan aktivitasnya dalam melakukan pengerukan. Dalam operasinya, kapal keruk ini akan bekerja di area waduk. Dan juga sangat cocok diaplikasikan di sungai dan rawa. Dalam perancangan sistem permesinannya ada beberapa parameter yang perlu diperhatikan antara lain lokasi pengerukan, kapasitas produksi, kedalaman pengerukan, jenis material yang akan dikeruk, ukuran kapal, dan akses menuju ke tempat kerja. Dalam skripsi ini, akan dilakukan beberapa variasi perhitungan, analisa dan desain rencana umum kapal keruk (ACSD. Perhitungan dan analisa yang dilakukan pada sistem permesinannya antara lain perhitungan kapasitas dan penentuan pompa hisap, perhitungan dan pemilihan mesin Independen drive, pemilihan cutterhead, perhitungan kapasitas dan penentuan ladder winch suction pipe, desain kapal keruk yang direncanakan. Selanjutnya, setelah dilakukan perhitungan dan analisa tersebut, penentuan spesifikasi dijadikan dasar dalam pemilihan komponen / unit pada sistem permesinan kapal keruk ACSD tersebut.

  13. Short-term effects of air pollution from biomass burning in mucociliary clearance of Brazilian sugarcane cutters.

    Science.gov (United States)

    Ferreira-Ceccato, Aline Duarte; Ramos, Ercy Mara Cípulo; de Carvalho, Luiz Carlos Soares; Xavier, Rafaella Fagundes; Teixeira, Marcos Fernando de Souza; Raymundo-Pereira, Paulo Augusto; Proença, Camila dos Anjos; de Toledo, Alessandra Choqueta; Ramos, Dionei

    2011-11-01

    Nasal mucociliary system is the first line of defense of the upper airways and may be affected acutely by exposure to particulate matter (PM) from biomass burning. Several epidemiologic studies have demonstrated a consistent association between levels of air pollution from biomass burning with increases in hospitalization for respiratory diseases and mortality. To determine the acute effects of exposure to particulate matter from biomass burning in nasal mucociliary transport by saccharin transit time (STT) test, we studied thirty-three non-smokers and twelve light smokers sugarcane cutters in two periods: pre-harvest season and 4 h after harvest at the first day after biomass burning. Lung function, exhaled carbon monoxide (CO), nasal symptoms questionnaire and mucociliary clearance (MC) were assessed. Exhaled CO was increased in smokers compared to non-smokers but did not change significantly after harvest. In contrast, STT was similar between smokers and non-smokers and decreased significantly after harvest in both groups (p acute exposure to particulate matter from sugarcane burned affects mucociliary clearance in smokers and non-smokers workers in the absence of symptoms.

  14. The mitochondrial genome of the leaf-cutter ant Atta laevigata: a mitogenome with a large number of intergenic spacers.

    Directory of Open Access Journals (Sweden)

    Cynara de Melo Rodovalho

    Full Text Available In this paper we describe the nearly complete mitochondrial genome of the leaf-cutter ant Atta laevigata, assembled using transcriptomic libraries from Sanger and Illumina next generation sequencing (NGS, and PCR products. This mitogenome was found to be very large (18,729 bp, given the presence of 30 non-coding intergenic spacers (IGS spanning 3,808 bp. A portion of the putative control region remained unsequenced. The gene content and organization correspond to that inferred for the ancestral pancrustacea, except for two tRNA gene rearrangements that have been described previously in other ants. The IGS were highly variable in length and dispersed through the mitogenome. This pattern was also found for the other hymenopterans in particular for the monophyletic Apocrita. These spacers with unknown function may be valuable for characterizing genome evolution and distinguishing closely related species and individuals. NGS provided better coverage than Sanger sequencing, especially for tRNA and ribosomal subunit genes, thus facilitating efforts to fill in sequence gaps. The results obtained showed that data from transcriptomic libraries contain valuable information for assembling mitogenomes. The present data also provide a source of molecular markers that will be very important for improving our understanding of genomic evolutionary processes and phylogenetic relationships among hymenopterans.

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

    Institute of Scientific and Technical Information of China (English)

    Cao Lixin; Dong Lei

    2015-01-01

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

  16. 岩石在盘形滚刀作用下的性能研究%Study on rock mechanical properties under the effect of disc cutter head

    Institute of Scientific and Technical Information of China (English)

    张照煌; 叶定海; 袁昕

    2011-01-01

    考虑岩石的各向异性,深入研究了岩石在盘形滚刀作用下的形变和剥落特点,建立了岩石在盘形滚刀作用下的力学模型,给出了岩石在盘形滚刀作用下形变的几何方程、物理方程和平衡方程。并通过对岩石在盘形滚刀垂直载荷和平面滚压载荷作用下的试验观察,提出在盘形滚刀垂直力的计算中以盘形滚刀侵入岩石而在岩石表面形成面积(双曲线围成)上的平均应力代替岩石的杨氏模量;在滚动力的计算中以岩石的抗拉强度代替剪切弹性模量,以抗剪强度代替A常数;盘形滚刀破岩侧向力计算中的岩石性能参数则取用杨氏模量。将此方案用于所建立的的力学模型,求得了盘形滚刀破岩的垂直力、滚动力和侧向力;计算结果均比已有压痕试验求得的垂直力、线性滚压岩石试验求得的垂直力和滚动力更精确。计算还获得了盘形滚刀破岩的侧向力,其结果也通过了试验验证。%In order to better understand the responsive patterns of 3-D spatiality of rock breaking effect of disc cutter and the anisotropism of rocks, a motion model for rock breaking by disc cutter is established, which is based on the study of the resulted deformation and desquamation features of rock, and applies the geometric equation, physical equation and equilibrium equation. Meanwhile, based on experimental observation and study of the indention and rolling of disc cutter on the rock, a theory is presented. The theory can be described as that for calculation of vertical force of disc cutter, Young's modulus shall be in the form of mean stress of the rock surface formed by the penetration of the disc cutter (the area of the rock surface is shown by the hyperbola). For computation of rolling force, the shear elastic modulus shall be taken as tensile strength, while the constant A shall be taken as the shear strength of the rock. For the calculation of the

  17. Finite Element Parameterized Modeling of and Analysis on Cutter Head of Shield Machine%盾构刀盘的有限元参数化建模及其分析

    Institute of Scientific and Technical Information of China (English)

    陈馈; 苏翠侠; 王燕群

    2011-01-01

    Modeling system of finite element model of typical cutter head is established in order to make rapid finite element analysis on the cutter head of shield machine. By means of this modeling system, automatic modeling and finite element analysis of the cutter head of shield machine are achieved, finite element simulation of tunnel boring is implemented, and the dynamic strength and rigidity under the action of coupling between the cutter head and the boring face are obtained. The paper can provide reference for the optimization design of cutter heads.%为快速进行盾构刀盘有限元分析,建立典型刀盘有限元模型建模系统,利用该系统实现了盾构刀盘自动建模和有限元分析,并进行了掘进过程的有限元仿真,得到了刀盘与掘进界面耦合作用下的动态强度、刚度,为刀盘的优化设计提供参考依据.

  18. Distribution of contact loads over the flank-land of the cutter with a rounded cutting edge

    Science.gov (United States)

    Kozlov, V.; Gerasimov, A.; Kim, A.

    2016-04-01

    In this paper, contact conditions between a tool and a workpiece material for wear-simulating turning by a cutter with a sharp-cornered edge and with a rounded cutting edge are analysed. The results of the experimental study of specific contact load distribution over the artificial flank wear-land of the cutter in free orthogonal turning of the disk from titanium alloy (Ti6Al2Mo2Cr), ductile (63Cu) and brittle (57Cu1Al3Mn) brasses are described. Investigations were carried out by the method of ‘split cutter’ and by the method of the artificial flank-land of variable width. The experiments with a variable feed rate and a cutting speed show that in titanium alloy machining with a sharp-cornered cutting edge the highest normal contact load (σh max = 3400…2200 MPa) is observed immediately at the cutting edge, and the curve has a horizontal region with the length of 0.2… 0.6 mm. At a distance from the cutting edge, the value of specific normal contact load is dramatically reduced to 1100…500 MPa. The character of normal contact load for a rounded cutting edge is different -it is uniform, and its value is approximately 2 times smaller compared to machining with a sharp-cornered cutting edge. In author’s opinion it is connected with generation of a seizure zone in a chip formation region and explains the capacity of highly worn-out cutting tools for titanium alloys machining. The paper analyses the distribution of tangential contact loads over the flank land, which pattern differs considerably for machining with a sharp-cornered edge and with a rounded cutting edge. Abbreviation and symbols: m/s - meter per second (cutting speed v); mm/r - millimeter per revolution (feed rate f); MPa - mega Pascal (specific contact load as a stress σ or τ) hf - the width of the flank wear land (chamfer) of the cutting tool, flank wear land can be natural or artificial like the one in this paper [mm]; xh - distance from the cutting edge on the surface of the flank-land [mm

  19. Magnetic anisotropy and organization of nanoparticles in heads and antennae of neotropical leaf-cutter ants, Atta colombica

    Science.gov (United States)

    Alves, Odivaldo C.; Srygley, Robert B.; Riveros, Andre J.; Barbosa, Marcia A.; Esquivel, Darci M. S.; Wajnberg, Eliane

    2014-10-01

    Oriented magnetic nanoparticles have been suggested as a good candidate for a magnetic sensor in ants. Behavioural evidence for a magnetic compass in neotropical leaf-cutter ants, Atta colombica (Formicidae: Attini), motivated a study of the arrangement of magnetic particles in the ants’ four major body parts by measuring the angular dependence of the ferromagnetic resonance spectra at room temperature. Spectra of the thoraces and those of the abdomens showed no significant angular dependence, while those of the antennae and those of the heads exhibited a periodic dependence relative to the magnetic field. Fitting of the angular dependence of the resonant field resulted in an unexpected magnetic anisotropy with uniaxial symmetry. High values of the first order anisotropy constant were observed for the magnetic material in antennae (-2.9  ×  105 erg cm-3) and heads (-1  ×  106 erg cm-3) as compared to body parts of other social insects. In addition, the magnitude of the anisotropy in the heads was comparable to that observed in magnetite nanoparticles of 4-5 nm diameter. For the antennae, the mean angle of the particles’ easy magnetization axis (EA) was estimated to be 41° relative to the straightened antenna’s long axis. For the heads, EA was approximately 60° relative to the head’s axis running from midway between the spines to the clypeus. These physical characteristics indicate organized magnetic nanoparticles with a potential for directional sensitivity, which is an important feature of magnetic compasses.

  20. National Radiological Fixed Lab Data

    Data.gov (United States)

    U.S. Environmental Protection Agency — The National Radiological Fixed Laboratory Data Asset includes data produced in support of various clients such as other EPA offices, EPA Regional programs, DOE,...

  1. Elevated Fixed Platform Test Facility

    Data.gov (United States)

    Federal Laboratory Consortium — The Elevated Fixed Platform (EFP) is a helicopter recovery test facility located at Lakehurst, NJ. It consists of a 60 by 85 foot steel and concrete deck built atop...

  2. Fixed Exchange Rates and Trade

    OpenAIRE

    Michael W. Klein; Jay C. Shambaugh

    2004-01-01

    A classic argument for a fixed exchange rate is its promotion of trade. Empirical support for this, however, is mixed. While one branch of research consistently shows a small negative effect of exchange rate volatility on trade, another, more recent, branch presents evidence of a large positive impact of currency unions on trade. This paper helps resolve this disconnect. Our results, which use a new data-based classification of fixed exchange rate regimes, show a large, significant effect of ...

  3. Design and Experiment on the Reciprocating Cutter for Vines%往复式葡萄藤切割器优化设计与试验

    Institute of Scientific and Technical Information of China (English)

    龙魁; 刘进宝; 张静; 杨宛章; 郭辉

    2014-01-01

    The structural principle of the reciprocating cutter for vines was studied .Meanwhile , the resistance , the en-ergy consumption and power were analyzed .An optimization mathematical model was established for the pursuit of mini-mal energy consumption .The optimization results including the cutter crank speed n=320 r/min , the crank radius of the Cutter r=50mm , the cutter trip s=100mm , the speed of the machine vm=0.9m/s and the length of machine cutting B=1.1m.Finally ,the experiment showd the results are validated and the datas are reliabled .Which can replace the ex-perimental data as the reference , provides areference for the development of low power design of vine pruning machine .%研究了往复式葡萄藤修剪机械切割器的结构原理,分析计算了往复式葡萄藤切割器工作行程的阻耗和功耗。以往复式葡萄藤切割器工作行程的阻耗和功耗最小为目标函数,建立优化设计的数学模型,优化计算结果为:割刀曲柄转速 n=320r/min,割刀曲柄半径r=50mm,切割器行程s=100mm,机器前进速度vm=0.9m/s,机器割幅B=1.1m。试验表明,优化设计结果合理,优化数据可靠,能替代试验数据作为参考依据,为低功耗葡萄藤修剪机的研发提供了一种设计参考。

  4. Research on plasma melted cladding high-abrasive intrinsic safe pick cutter%等离子熔覆高耐磨无火花本安型镐型截齿研究

    Institute of Scientific and Technical Information of China (English)

    孙玉宗

    2009-01-01

    The plasma melted cladding reinforced technology was applied to have a melted cladding metal ceramic coating on the head of the cutter.During the spraying quenching of the cutter,the insulation protection coating on the cutter head could protect the hard alloy cutter,also could effectively protect the early dropping of the hard alloy tip from the cutter and could eliminate the potential danger of the welding seam and hard alloy tip affected by the conventional first rod and then welding quality improvement or salty bath isothermy heat treatment.Thus the integral performances of the cutter could be highly improved.The metal ceramic layer could effectively prevent the sparks occurred during the coal mining operation and could improve the safety of the coal production.%采用等离子熔覆强化技术在截齿的头部熔覆一层专用金属陶瓷层,截齿喷淋淬火时截齿头部加保温防护罩保护硬质合金刀头,不仅有效的保护了截齿硬质合金刀头不过早脱落,也避免了传统工艺先钎焊后调质或盐浴等温淬火对焊缝和硬质合金刀头的潜在危害,使截齿的整体性能大幅度提高.金属陶瓷层有效防止了采煤时产生火花,提高了煤炭生产的安全性.

  5. Study on cutters cutting torque of EPB shield based on slip-line field%基于滑移线场的土压平衡盾构刀具切削扭矩研究

    Institute of Scientific and Technical Information of China (English)

    赵丹; 彭立敏; 雷明锋; 陈露

    2013-01-01

    为了较合理地估算刀盘的切削扭矩,对刀盘2种主要刀具即切刀和滚刀的切削扭矩进行研究:首先基于塑性力学中滑移线场,对滚刀和切刀分别建立与其切削机制相对应的塑性力学模型,推导具体的表达式;然后,根据盾构刀具的配置参数及红层掘进参数对刀盘的切削扭矩进行计算,分项求和得到刀盘总扭矩.最后对刀盘计算总扭矩与施工实测总扭矩相比较,并分析理论计算模型存在的误差原因.研究结果表明:滚刀在红层中受均匀磨损,磨损量小,刀盘扭矩的实际装备系数为3.2,有一定的富余.研究结果可为盾构刀盘的设计、施工提供参考.%In order to estimate the cutting torque of shield cutter head resonablely,two main tools of cutters and roller-cutters were studied:Firstly,based on the slip-line field of plastic mechanics,mechanics models were established corresponding to cutting mechanism of cutters and roller-cutters,and specific expression was derived.Then,the total torque in accordance with shield tool parameters and red-stratum excavation parameters by means of the sum over T1,T2 and T3 was derived.Finally,the calculated torque was compared with the measured torque on-site,and the error causes well also analyzed.The results show that the abrasion value is small when roller-cutters are under uniform wear in red-layer.The actual equipment coefficient of cutter torque is 3.2 which means there exists certain surplus,and the research results can provide reference for EPB cutter design and construction.

  6. A Comparison Simulation of Fixed-fixed Type MEMS Switches

    Science.gov (United States)

    Rezazadeh, G.; Sadeghian, H.; Malekpour, E.

    2006-04-01

    In the present work pull-in voltage of fixed-fixed end type MEMS switches with variative electrostatic area has been calculated using a distributed model and applying a full nonlinear finite difference discretizing method. The governing nonlinear differential equation has been derived using of the variational principle for multi domain electromechanical coupled system. The numerical results of the beam with variative electrostatic area with the results of Coupled-Domain Finite Element method have been compared and very good agreement has been achieved.

  7. Diclofenac Induced Fixed Drug Eruption

    Directory of Open Access Journals (Sweden)

    Dr. Umeshchandra C Honnaddi

    2016-02-01

    Full Text Available Background: Diclofenac is the most commonly used non-steroidal anti-inflammatory drug (NSAID for treating various inflammatory and painful conditions. It is generally well tolerated; gastric upset is the most common adverse effect. However very few cases of fixed drug eruptions were reported. Here we present a case of Diclofenac Induced Fixed Drug Eruption. A 62 year old male patient developed fixed drug eruptions with plaques on left thigh two days after receiving diclofenac for osteoarthritic pain. Other etiologies including insect bite, infections were ruled out. One week later after stopping the drug, the lesions were subsided. Diclofenac was strongly suspected as the casual drug. CD8+ effector T-cells have shown to play an important role. However it seems to be a reversible and drug related event. Although it is not life-threatening, fixed drug eruption can have significant effect on the quality of life of patients.Conclusion: Diclofenac is one of the most commonly prescribed NSAIDs by the Physicians. It is usually well tolerated, gastric upset is the most common adverse effect noted with this drug. This case is being reported to highlight a drug as safe as Diclofenac may also be associated with Fixed Drug Eruptions.

  8. 盾构机刀盘多电机同步驱动研究%Synchronously research of the shield machine cutter drive

    Institute of Scientific and Technical Information of China (English)

    赵刚; 刘德全

    2012-01-01

    盾构机/5盘由多个电机共同驱动,需要对多电机进行同步控制和负载平衡控制,即让电机速度相同的情况下,承担相应的平均负载。本文描述了多电机同步控制的几种方式,并对各种控制方式的特点进行了比较,同时介绍了中8780土压平衡盾构机刀盘驱动的实际应用。%The shield machine cutter is driven together by several motors. We need to carry on the synchronous and the load balance controls to many motors, then let the motor speed is same under average load. This text described a few methods that many motors synchronously control and compared the characteristics of various control method. At the same time introducing actual application of the q08780 Earth Press Balance shield machine cutter drive.

  9. Enrichment and Broad Representation of Plant Biomass-Degrading Enzymes in the Specialized Hyphal Swellings of Leucoagaricus gongylophorus, the Fungal Symbiont of Leaf-Cutter Ants

    Energy Technology Data Exchange (ETDEWEB)

    Aylward, Frank O.; Khadempour, Lily; Tremmel, Daniel; McDonald, Bradon R.; Nicora, Carrie D.; Wu, Si; Moore, Ronald J.; Orton, Daniel J.; Monroe, Matthew E.; Piehowski, Paul D.; Purvine, Samuel O.; Smith, Richard D.; Lipton, Mary S.; Burnum-Johnson, Kristin E.; Currie, Cameron R.

    2015-08-28

    Leaf-cutter ants are prolific and conspicuous Neotropical herbivores that derive energy from specialized fungus gardens they cultivate using foliar biomass. The basidiomycetous cultivar of the ants, Leucoagaricus gongylophorus, produces specialized hyphal swellings called gongylidia that serve as the primary food source of ant colonies. Gongylidia also contain lignocellulases that become concentrated in ant digestive tracts and are deposited within fecal droplets onto fresh foliar material as it is foraged by the ants. Although the enzymes concentrated by L. gongylophorus within gongylidia are thought to be critical to the initial degradation of plant biomass, only a few enzymes present in these hyphal swellings have been identified. Here we use proteomic methods to identify proteins present in the gongylidia of three Atta cephalotes colonies. Our results demonstrate that a diverse but consistent set of enzymes is present in gongylidia, including numerous lignocellulases likely involved in the degradation of polysaccharides, plant toxins, and proteins. Overall, gongylidia contained over three-quarters of all lignocellulases identified in the L. gongylophorus genome, demonstrating that the majority of the enzymes produced by this fungus for biomass breakdown are ingested by the ants. We also identify a set of 23 lignocellulases enriched in gongylidia compared to whole fungus garden samples, suggesting that certain enzymes may be particularly important in the initial degradation of foliar material. Our work sheds light on the complex interplay between leaf-cutter ants and their fungal symbiont that allows for the host insects to occupy an herbivorous niche by indirectly deriving energy from plant biomass.

  10. 数控铣床刀具半径补偿的应用探讨%Application ofCutter Ra dius Compensationi n Numerical Control Milling Machine

    Institute of Scientific and Technical Information of China (English)

    陈松

    2013-01-01

    The cutter radius compensation command is a very important technique in the operation of numerical control milling machine ,also known as "cutter compensation".It is only after mastering the instructions on the basis of correct and flexible applications and determining its value that the programming and processing of parts can therefore be completed ,which is essential to guarantee the accuracy of the contour of the machining part .%  在数控铣床加工中,刀具半径补偿指令是非常重要的指令,又称“刀补”。“刀补”指令对完成零件的编程加工,保证零件轮廓的准确性及加工精度至关重要。通过分析、比较和实践,得到了正确、灵活应用“刀补”指令和确定“刀补”指令数值的方法。应用该方法,可以顺利解决一些较复杂零件的数控铣削加工问题。

  11. The Flexible Use of the Cutter Tables in Periodical Shelving%克特号在期刊排架工作中的灵活应用

    Institute of Scientific and Technical Information of China (English)

    王晓华

    2011-01-01

    目前,各图书馆期刊排架方法很多,最常见的还是刊名字顺排架和分类排架。我馆在借鉴北大馆的经验基础上,灵活应用克特号完成中文期刊改号工作。文章主要介绍期刊索刊号的确立,刊名克特号的应用规则,期刊特殊情况的处理办法,以及学报的特别处理等。%Many periodicals shelving protocols are currently used by different libraries,but shelving based on the classification and based on the journal name alphabet are still the two most commonly used methods.Inner Mongolia University library has recently changed the codes for all Chinese periodicals by making the flexible use of the Cutter Tables inspired by the similar work done in Beijing University library.This article mainly focuses on introducing various protocols we have used during the code-change project,including periodicals indexing,using of the journal name Cutter numbers,special cases handling,and the special treatment for university journals.

  12. Evidence of the Big Fix

    CERN Document Server

    Hamada, Yuta; Kawana, Kiyoharu

    2014-01-01

    We give an evidence of the Big Fix. The theory of wormholes and multiverse suggests that the parameters of the Standard Model are fixed in such a way that the total entropy at the late stage of the universe is maximized, which we call the maximum entropy principle. In this paper, we discuss how it can be confirmed by the experimental data, and we show that it is indeed true for the Higgs vacuum expectation value $v_{h}$. We assume that the baryon number is produced by the sphaleron process, and that the current quark masses, the gauge couplings and the Higgs self coupling are fixed when we vary $v_{h}$. It turns out that the existence of the atomic nuclei plays a crucial role to maximize the entropy. This is reminiscent of the anthropic principle, however it is required by the fundamental low in our case.

  13. Evidence of the big fix

    Science.gov (United States)

    Hamada, Yuta; Kawai, Hikaru; Kawana, Kiyoharu

    2014-06-01

    We give an evidence of the Big Fix. The theory of wormholes and multiverse suggests that the parameters of the Standard Model are fixed in such a way that the total entropy at the late stage of the universe is maximized, which we call the maximum entropy principle. In this paper, we discuss how it can be confirmed by the experimental data, and we show that it is indeed true for the Higgs vacuum expectation value vh. We assume that the baryon number is produced by the sphaleron process, and that the current quark masses, the gauge couplings and the Higgs self-coupling are fixed when we vary vh. It turns out that the existence of the atomic nuclei plays a crucial role to maximize the entropy. This is reminiscent of the anthropic principle, however it is required by the fundamental law in our case.

  14. Leaf Cutter Ant (Atta cephalotes) Soil Modification and In Situ CO2 Gas Dynamics in a Neotropical Wet Forest

    Science.gov (United States)

    Fernandez Bou, A. S.; Carrasquillo Quintana, O.; Dierick, D.; Harmon, T. C.; Johnson, S.; Schwendenmann, L.; Zelikova, T. J.

    2016-12-01

    The goal of this work is to advance our understanding of soil carbon cycling in highly productive neotropical wet forests. More specifically, we are investigating the influence of leaf cutter ants (LCA) on soil CO2 gas dynamics in primary and secondary forest soils at La Selva Biological Station, Costa Rica. LCA are the dominant herbivore in tropical Americas, responsible for as much as 50% of the total herbivory. Their presence is increasing and their range is expanding because of forest fragmentation and other human impacts. We installed gas sampling wells in LCA (Atta cephalotes) nest and control sites (non-nests in the same soil and forest settings). The experimental design encompassed land cover (primary and secondary forest) and soil type (residual and alluvial). We collected gas samples monthly over an 18-month period. Several of the LCA nests were abandoned during this period. Nevertheless, we continued to sample these sites for LCA legacy effects. In several of the sites, we also installed sensors to continuously monitor soil moisture content, temperature, and CO2 levels. Within the 18-month period we conducted a 2-month field campaign to collect soil and nest vent CO2 efflux data from 3 of the nest-control pairs. Integrating the various data sets, we observed that for most of the sites nest and control soils behaved similarly during the tropical dry season. However, during the wet season gas well CO2 concentrations increased in the control sites while levels in the nests remained at dry season levels. This outcome suggests that ants modify soil gas transport properties (e.g., tortuosity). In situ time series and efflux sampling campaign data corroborated these findings. Abandoned nest CO2 levels were similar to those of the active nests, supporting the notion of a legacy effect from LCA manipulations. For this work, the period of abandonment was relatively short (several months to 1 year maximum), which appears to be insufficient for estimating the

  15. Fixed-point signal processing

    CERN Document Server

    Padgett, Wayne T

    2009-01-01

    This book is intended to fill the gap between the ""ideal precision"" digital signal processing (DSP) that is widely taught, and the limited precision implementation skills that are commonly required in fixed-point processors and field programmable gate arrays (FPGAs). These skills are often neglected at the university level, particularly for undergraduates. We have attempted to create a resource both for a DSP elective course and for the practicing engineer with a need to understand fixed-point implementation. Although we assume a background in DSP, Chapter 2 contains a review of basic theory

  16. Perfect and Imperfect Gauge Fixing

    CERN Document Server

    Shirzad, A

    2006-01-01

    Gauge fixing may be done in different ways. We show that using the chain structure to describe a constrained system, enables us to use either a perfect gauge, in which all gauged degrees of freedom are determined; or an imperfect gauge, in which some first class constraints remain as subsidiary conditions to be imposed on the solutions of the equations of motion. We also show that the number of constants of motion depends on the level in a constraint chain in which the gauge fixing condition is imposed. The relativistic point particle, electromagnetism and the Polyakov string are discussed as examples and perfect or imperfect gauges are distinguished.

  17. Fixed effects analysis of variance

    CERN Document Server

    Fisher, Lloyd; Birnbaum, Z W; Lukacs, E

    1978-01-01

    Fixed Effects Analysis of Variance covers the mathematical theory of the fixed effects analysis of variance. The book discusses the theoretical ideas and some applications of the analysis of variance. The text then describes topics such as the t-test; two-sample t-test; the k-sample comparison of means (one-way analysis of variance); the balanced two-way factorial design without interaction; estimation and factorial designs; and the Latin square. Confidence sets, simultaneous confidence intervals, and multiple comparisons; orthogonal and nonorthologonal designs; and multiple regression analysi

  18. Development of Portable Circular Saw Multifunctional Mulberry Shoot Cutter%便携式圆盘锯多功能桑树伐条机的研制

    Institute of Scientific and Technical Information of China (English)

    陈伟国; 朱滢元; 董瑞华; 计东风; 孙海燕; 戴建忠

    2012-01-01

    为推进省力化栽桑养蚕技术体系的实施,以适合桑枝剪伐的农艺要求及成本低、结构简单、操作安全、效率高、性能稳定、机型轻便为设计目标,研制出便携式圆盘锯多功能桑树伐条机.该机采用蓄电池供给电源,直流电机驱动木工圆盘锯片以6 000 r/min左右的高速旋转,完成对桑枝条的横截切割.该机的主要性能特点是:桑枝剪伐截面光滑平整;整机结构简单,购置费用低,使用轻便灵活,能够显著降低桑枝剪伐的劳动强度;机械效率高,桑园伐条工效是手工剪伐的3倍左右;设计的分体式防护罩结构能最大程度保护操作者的安全;换装金属磨光片、陶瓷切割片等工作刀具后可扩展多种用途.该机已获得国家实用新型专利(专利号:ZL201020541087.0).%To advance the implementation of labor-saving technology in mulberry cultivation and silkworm rearing, a portable circular saw multifunctional mulberry shoot cutter was developed to meet the agricultural demands of cutting mulberry branch with low cost, simple structure, safe operation, high efficiency, stable performance and portability as the design target. This cutter uses DC motor powered by storage battery to drive a carpenter's circular saw at a rotating speed of about 6 000 r/min to transversely cut the mulberry branch. Major functioning features of this cutter include smooth and level cuts to mulberry branch, simple structure of the whole machine with low cost and easy operation, effectiveness in lowering labor intensity of cutting mulberry branches, and high mechanical efficiency (work efficiency is about 3 times to manual cutting). The designed split-type protective cover can prevent the circular saw from injuring human body to the maximum extent. After replacement with other cutting tools such as metal polishing sheet and ceramic cutter, the cutter can be used for other purposes. This machine has obtained the National Practical New

  19. TBM滚刀破岩过程影响因素数值模拟研究%Numerical simulaiton of influence factors for rock fragmentation by TBM cutters

    Institute of Scientific and Technical Information of China (English)

    孙金山; 陈明; 陈保国; 卢文波; 周传波

    2011-01-01

    全断面岩石掘进机(TBM)的破岩效率主要受刀盘设计和岩体特征的影响.采用颗粒流方法建立了岩石试件与滚刀的数值模型,对TBM滚刀破岩过程的影响因素进行了分析.研究表明,单刃滚刀交替作用下强度较低的岩石中易形成规则的张拉裂纹而生成较大岩碴;强度较高的岩石中滚刀的侧向挤压促使形成块度较小的片状岩碴;双刃滚刀作用下岩石表面受到强烈挤压后出现较大的拉应力,使岩石更易破碎,且仅在强度较高的岩石中才易形成透镜状岩碴.滚刀破岩过程中存在能耗最小的最佳间距,该最佳间距随着岩石强度的增大而减小.滚刀破岩过程中,结构面对裂纹扩展具有显著的控制性作用,并阻隔损伤向结构面下的岩石中渗透;随着结构面与滚刀侵入方向夹角的减小,结构面将引导裂纹向岩石深部扩展,而当夹角较大时,结构面则会引导裂纹横向扩展,易导致大块岩碴的形成.%The cutterhead and rock mass characteristics affect the excavation efficiency of full face rock tunnel boring machine (TBM) strongly.The numerical models are made by the particle flow code method (PFC2D) to simulate the rock fragmentation under TBM disc cutters.Numerical simulation tests show that some factors influence the rock fragmentation process strongly.In the relative weak rocks, the regular tension cracks and the big mucks form more easily, when the disc cutters penetrate rocks altemately; in hard rocks,the formation of small disc shape mucks depends on the lateral extrusion of cutter rings.Under the double disc cutters, the rocks crush more easily because of the tension stress which comes form strong compression of cuaers, and the disc shape mucks only form in very hard rocks.There is optimal cutter spacing for different strength rocks, which increase with rock strength decreases.In the process of rock fragmentation, discontinuities control the propagation process of cracks

  20. Flat coalgebraic fixed point logics

    CERN Document Server

    Schröder, Lutz

    2010-01-01

    Fixed point logics have a wide range of applications in computer science, in particular in artificial intelligence and concurrency. The most expressive logics of this type are the mu-calculus and its relatives. However, popular fixed point logics tend to trade expressivity for simplicity and readability, and in fact often live within the single variable fragment of the mu-calculus. The family of such flat fixed point logics includes, e.g., CTL, the *-nesting-free fragment of PDL, and the logic of common knowledge. Here, we extend this notion to the generic semantic framework of coalgebraic logic, thus covering a wide range of logics beyond the standard mu-calculus including, e.g., flat fragments of the graded mu-calculus and the alternating-time mu-calculus (such as ATL), as well as probabilistic and monotone fixed point logics. Our main results are completeness of the Kozen-Park axiomatization and a timed-out tableaux method that matches EXPTIME upper bounds inherited from the coalgebraic mu-calculus but avo...

  1. Landau Gauge Fixing on GPUs

    CERN Document Server

    Cardoso, Nuno; Bicudo, Pedro; Oliveira, Orlando

    2012-01-01

    In this paper we present and explore the performance of Landau gauge fixing in GPUs using CUDA. We consider the steepest descent algorithm with Fourier acceleration, and compare the GPU performance with a parallel CPU implementation. Using $32^4$ lattice volumes, we find that the computational power of a single Tesla C2070 GPU is equivalent to approximately 256 CPU cores.

  2. Fixed drug eruption to tartrazine.

    Science.gov (United States)

    Orchard, D C; Varigos, G A

    1997-11-01

    An 11-year-old girl with a recurrent fixed drug eruption to tartrazine on the dorsum of the left hand is presented. Oral provocation tests to both the suspected food, an artificially coloured cheese crisp, and to tartrazine were positive. This case highlights fire need to consider artificial flavours, colours and preservatives as potential culprits in classic drug eruptions.

  3. Adhesives for fixed orthodontic bands.

    Science.gov (United States)

    Millett, Declan T; Glenny, Anne-Marie; Mattick, Rye Cr; Hickman, Joy; Mandall, Nicky A

    2016-10-25

    Orthodontic treatment involves using fixed or removable appliances (dental braces) to correct the positions of teeth. It has been shown that the quality of treatment result obtained with fixed appliances is much better than with removable appliances. Fixed appliances are, therefore, favoured by most orthodontists for treatment. The success of a fixed orthodontic appliance depends on the metal attachments (brackets and bands) being attached securely to the teeth so that they do not become loose during treatment. Brackets are usually attached to the front and side teeth, whereas bands (metal rings that go round the teeth) are more commonly used on the back teeth (molars). A number of adhesives are available to attach bands to teeth and it is important to understand which group of adhesives bond most reliably, as well as reducing or preventing dental decay during the treatment period. To evaluate the effectiveness of the adhesives used to attach bands to teeth during fixed appliance treatment, in terms of:(1) how often the bands come off during treatment; and(2) whether they protect the banded teeth against decay during fixed appliance treatment. The following electronic databases were searched: Cochrane Oral Health's Trials Register (searched 2 June 2016), Cochrane Central Register of Controlled Trials (CENTRAL; 2016, Issue 5) in the Cochrane Library (searched 2 June 2016), MEDLINE Ovid (1946 to 2 June 2016) and EMBASE Ovid (1980 to 2 June 2016). We searched ClinicalTrials.gov and the World Health Organization International Clinical Trials Registry Platform for ongoing trials. No restrictions were placed on the language or date of publication when searching the electronic databases. Randomised and controlled clinical trials (RCTs and CCTs) (including split-mouth studies) of adhesives used to attach orthodontic bands to molar teeth were selected. Patients with full arch fixed orthodontic appliance(s) who had bands attached to molars were included. All review authors

  4. Can mushrooms fix atmospheric nitrogen?

    Indian Academy of Sciences (India)

    H S Jayasinghearachchi; Gamini Seneviratne

    2004-09-01

    It is generally reported that fungi like Pleurotus spp. can fix nitrogen (N2). The way they do it is still not clear. The present study hypothesized that only associations of fungi and diazotrophs can fix N2. This was tested in vitro. Pleurotus ostreatus was inoculated with a bradyrhizobial strain nodulating soybean and P. ostreatus with no inoculation was maintained as a control. At maximum mycelial colonization by the bradyrhizobial strain and biofilm formation, the cultures were subjected to acetylene reduction assay (ARA). Another set of the cultures was evaluated for growth and nitrogen accumulation. Nitrogenase activity was present in the biofilm, but not when the fungus or the bradyrhizobial strain was alone. A significant reduction in mycelial dry weight and a significant increase in nitrogen concentration were observed in the inoculated cultures compared to the controls. The mycelial weight reduction could be attributed to C transfer from the fungus to the bradyrhizobial strain, because of high C cost of biological N2 fixation. This needs further investigations using 14C isotopic tracers. It is clear from the present study that mushrooms alone cannot fix atmospheric N2. But when they are in association with diazotrophs, nitrogenase activity is detected because of the diazotrophic N2 fixation. It is not the fungus that fixes N2 as reported earlier. Effective N2 fixing systems, such as the present one, may be used to increase protein content of mushrooms. Our study has implications for future identification of as yet unidentified N2 systems occurring in the environment.

  5. On Fixing number of Functigraphs

    OpenAIRE

    Fazil, Muhammad; Javaid, Imran; Murtaza, Muhammad

    2016-01-01

    The fixing number of a graph $G$ is the order of the smallest subset $S$ of its vertex set $V(G)$ such that stabilizer of $S$ in $G$, $\\Gamma_{S}(G)$ is trivial. Let $G_{1}$ and $G_{2}$ be disjoint copies of a graph $G$, and let $g:V(G_{1})\\rightarrow V(G_{2})$ be a function. A functigraph $F_{G}$ consists of the vertex set $V(G_{1})\\cup V(G_{2})$ and the edge set $E(G_{1})\\cup E(G_{2})\\cup \\{uv:v=g(u)\\}$. In this paper, we study the behavior of the fixing number in passing from $G$ to $F_{G}...

  6. Prediction algorithm for rotational speed of workpiece's revolving shaftwith numerical cam grinder%凸轮轴磨床工件旋转轴转速预测算法的研究

    Institute of Scientific and Technical Information of China (English)

    王洪; 戴瑜兴; 许世雄; 王东昱

    2011-01-01

    Acceleration and deceleration of grinding in cam based on method of cubic B-spline curve interpolation is weak, which is easy to grind much and insufficiently.According to the mathematic model of cam grinding,the theoretical and practi cable speed,acceleration and the differential acceleration of cam's feed shaft is analyzed.A processing method of forecasting rotational speed of workpiece is proposed,and the rotational workpiece is automatically underspeeded when the speed is rap idly variated.The cam grinding software is designed based on this adaptive interpolation algorithm and Matrix VB,and then it is applied to the YTMK-CNC8336,which is digital and high speed cam grinder.The testing results show that the error of cam grinding with this proposed method is less than 0.01 mm,and the roughness is less.%采用三次B样条曲线插补的凸轮磨削加减速能力不足,易产生过磨和少磨.根据凸轮磨削的数学模型,分析了砂轮进给轴运动的理论与实际速度、加速度、加加速度,提出了一种预测工件旋转轴转速的加工方法,在速度变化剧烈处自动降低工件旋转轴转速,以避免加速度和加加速度的变化对伺服系统造成的机械冲击,利用MatrixVB控件编程技术,设计了凸轮轴磨削软件,并将其移植到YTMK-CNC8326全数控高速凸轮轴磨床中.测试表明,采用该方法磨削的凸轮轴型线误差小于±0.01 mm,工件表面粗糙度得到明显改善,实现了凸轮轴的精密加工.

  7. Oral rehabilitation with fixed prosthesis

    OpenAIRE

    Watanabe Velásquez, Romel; Dpto. Académico Estomatología Rehabilitadora. Facultad Odontología. UNMSM. Lima, Perú.; Salcedo Moncada, Doris; Dpto. Académico Estomatología Rehabilitadora. Facultad Odontología. UNMSM. Lima, Perú.; Ochoa Tataje, Julio; Dpto. Académico Estomatología Rehabilitadora. Facultad Odontología. UNMSM. Lima, Perú; Horna Palomino, Hernán; Dpto. Académico Estomatología Rehabilitadora. Facultad Odontología. UNMSM. Lima, Perú.; Herrera Cisneros, Marco; Dpto. Académico Estomatología Rehabilitadora. Facultad Odontología. UNMSM. Lima, Perú.; Paz Fernández, Juan José; Dpto. Académico Estomatología Rehabilitadora. Facultad Odontología. UNMSM. Lima, Perú.

    2014-01-01

    This treatment was carried out in a 58 years old male patient, who has had the antecedent of a car crash accident two years before; he loosed several teeth and fractured others. Pulp necrosis and alteration of occlusal plane occurred. Because of the pathologies presented, it was installed a multidisciplinary treatment phase having periodontal, endodontic, surgical and orthodontic procedures, tehe installation of posts, crowns and fixed bridges. Treatment was carried out for five months. El...

  8. Zirconia in fixed implant prosthodontics.

    Science.gov (United States)

    Guess, Petra Christine; Att, Wael; Strub, Joerg Rudolf

    2012-10-01

    CAD/CAM technology in combination with zirconia ceramic has increasingly gained popularity in implant dentistry. This narrative review presents the current knowledge on zirconia utilized as framework material for implant-borne restorations and implant abutments, laboratory tests and developments, clinical performance, and possible future trends for implant dentistry are addressed. A review of available literature from 1990 through 2010 was conducted with search terms zirconia,"implants,"abutment,"crown," and "fixed dental prosthesis" using electronic databases (PubMed) and manual searching. Latest applications of zirconia in implant dentistry include implant abutments, multiple unit and full-arch frameworks as well as custom-made bars to support fixed and removable prostheses. High biocompatibility, low bacterial surface adhesion as well as favorable chemical properties of zirconia ceramics are reported. Zirconia stabilized with yttrium oxide exhibits high flexural strength and fracture toughness due to a transformation toughening mechanism. Preliminary clinical data confirmed the high stability of zirconia for abutments and as a framework material for implant borne crowns and fixed dental prostheses. Zirconia abutment or framework damage has rarely been encountered. However, veneering porcelain fractures are the most common technical complication in implant-supported zirconia restorations. These porcelain veneer failures have led to concerns regarding differences in coefficient of thermal expansions between core and veneering porcelain and their respective processing techniques. As presently evidence of clinical long-term data is missing, caution with regard to especially extensive implant-borne zirconia frameworks is recommended. © 2010 Wiley Periodicals, Inc.

  9. A fixed-point farrago

    CERN Document Server

    Shapiro, Joel H

    2016-01-01

    This text provides an introduction to some of the best-known fixed-point theorems, with an emphasis on their interactions with topics in analysis. The level of exposition increases gradually throughout the book, building from a basic requirement of undergraduate proficiency to graduate-level sophistication. Appendices provide an introduction to (or refresher on) some of the prerequisite material and exercises are integrated into the text, contributing to the volume’s ability to be used as a self-contained text. Readers will find the presentation especially useful for independent study or as a supplement to a graduate course in fixed-point theory. The material is split into four parts: the first introduces the Banach Contraction-Mapping Principle and the Brouwer Fixed-Point Theorem, along with a selection of interesting applications; the second focuses on Brouwer’s theorem and its application to John Nash’s work; the third applies Brouwer’s theorem to spaces of infinite dimension; and the fourth rests ...

  10. Profiling procedure for disk cutter to generate the male rotor, screw compressors component, using the “Substitute Family Circle” - graphic method in AUTOCAD environment

    Science.gov (United States)

    Popa, CL; Popa, V.

    2016-11-01

    This paper proposes a profiling method for the tool which generates the helical groove of male rotor, screw compressor component. The method is based on a complementary theorem of surfaces enveloping - "Substitute Family Circles Method”. The specific theorem of family circles of substitution has been applied using AUTOCAD graphics design environment facility. The frontal view of the male rotor, screw compressor component, has been determinate knowing the transverse profile of female rotor, and using this theorem of "Substitute Family Circle". The three-dimensional model of the rotor makes possible to apply the same theorem, leading to the surface of revolution enveloping the helical surface. An application will be also presented to determine the axial profile of the disk cutter, numeric and graphics, following the proposed algorithm.

  11. Influence of rare-earth modification on the properties of 18KhN2MFL steel for drill bit roller cutters

    Energy Technology Data Exchange (ETDEWEB)

    Evseev, P.P.; Zhirkin, Y.N.

    1986-03-01

    This paper examines the influence of rare-earth metals on the behavior of nonmetallic inclusions, the physical and mechanical properties, the critical transformation points, and the macrostructure of 18KhN2MFL cast steel used for the production of drill bit roller cutters with a diameter of 295 mm and more. The nonmetallic inclusion investigation results showed that for 18KhN2MFL steel deoxidized with aluminum, two types of inclusions are characteristic: sharp angled alumina inclusions and globular manganese sulfides with hardnesses of 2200 HV and 190 HV, respectively. The wear resistance tests showed that the rare-earth-metal-modified steel possesses higher abrasive wear resistance as compared with the unmodified; the relative wear resistance of such steel increases by 14-23%.

  12. Enrichment and Broad Representation of Plant Biomass-Degrading Enzymes in the Specialized Hyphal Swellings of Leucoagaricus gongylophorus, the Fungal Symbiont of Leaf-Cutter Ants.

    Science.gov (United States)

    Aylward, Frank O; Khadempour, Lily; Tremmel, Daniel M; McDonald, Bradon R; Nicora, Carrie D; Wu, Si; Moore, Ronald J; Orton, Daniel J; Monroe, Matthew E; Piehowski, Paul D; Purvine, Samuel O; Smith, Richard D; Lipton, Mary S; Burnum-Johnson, Kristin E; Currie, Cameron R

    2015-01-01

    Leaf-cutter ants are prolific and conspicuous constituents of Neotropical ecosystems that derive energy from specialized fungus gardens they cultivate using prodigious amounts of foliar biomass. The basidiomycetous cultivar of the ants, Leucoagaricus gongylophorus, produces specialized hyphal swellings called gongylidia that serve as the primary food source of ant colonies. Gongylidia also contain plant biomass-degrading enzymes that become concentrated in ant digestive tracts and are deposited within fecal droplets onto fresh foliar material as ants incorporate it into the fungus garden. Although the enzymes concentrated by L. gongylophorus within gongylidia are thought to be critical to the initial degradation of plant biomass, only a few enzymes present in these hyphal swellings have been identified. Here we use proteomic methods to identify proteins present in the gongylidia of three Atta cephalotes colonies. Our results demonstrate that a diverse but consistent set of enzymes is present in gongylidia, including numerous plant biomass-degrading enzymes likely involved in the degradation of polysaccharides, plant toxins, and proteins. Overall, gongylidia contained over three quarters of all biomass-degrading enzymes identified in the L. gongylophorus genome, demonstrating that the majority of the enzymes produced by this fungus for biomass breakdown are ingested by the ants. We also identify a set of 40 of these enzymes enriched in gongylidia compared to whole fungus garden samples, suggesting that certain enzymes may be particularly important in the initial degradation of foliar material. Our work sheds light on the complex interplay between leaf-cutter ants and their fungal symbiont that allows for the host insects to occupy an herbivorous niche by indirectly deriving energy from plant biomass.

  13. Simple and rapid fabrication of disposable carbon-based electrochemical cells using an electronic craft cutter for sensor and biosensor applications.

    Science.gov (United States)

    Afonso, André S; Uliana, Carolina V; Martucci, Diego H; Faria, Ronaldo C

    2016-01-01

    This work describes the construction of an all-plastic disposable carbon-based electrochemical cell (DCell) using a simple procedure based on the use of a home cutter printer for prototyping and laminating. The cutter printer and adhesive vinyl films were used to produce three electrodes in an electrochemical cell layout, and a laminating process was then used to define the geometric area and insulate the electrodes. The DCell showed excellent performance in several applications including the determination of toxic metals in water samples, the immobilization of DNA and the detection of Salmonella. An unmodified DCell was applied for Pb and Cd detection in the range of 100-300 ng mL(-1) with a limit of detection of 50 and 39 ng mL(-1) for Cd and Pb, respectively. DNA was successfully immobilized on a DCell and used for studies of interaction between bisphenol A and DNA. The square wave voltammetry of a DNA modified DCell presented a guanine oxidation current 2.5 times greater after exposure of the electrode to bisphenol A and no current variation for the adenine moiety indicating that bisphenol A showed a preference for DNA interaction sites. A magneto-immunoassay was developed using a DCell for Salmonella detection in milk samples. The system presented a linear range from 100 to 700 cells mL(-1) with a limit of detection of 100 cells mL(-1) and good recovery values between 93% and 101% in milk samples, with no interference from Escherichia coli. Using the proposed method, hundreds of DCells can be assembled in less than two hours, at a material cost of less than US $0.02 per cell. The all-plastic disposable electrochemical cell developed was successfully applied as an electrochemical sensor and biosensor. The feasibility of the developed all-plastic disposable electrochemical cell was demonstrated in applications as both sensor and biosensor.

  14. GOLD and the fixed ratio

    Directory of Open Access Journals (Sweden)

    Vestbo J

    2012-09-01

    Full Text Available Jørgen VestboUniversity of Manchester, Manchester, UKI read with interest the paper entitled "Diagnosis of airway obstruction in the elderly: contribution of the SARA study" by Sorino et al in a recent issue of this journal.1 Being involved in the Global Initiative for Obstructive Lung Diseases (GOLD, it is nice to see the interest sparked by the GOLD strategy document. However, in the paper by Sorino et al, there are a few misunderstandings around GOLD and the fixed ratio (forced expiratory volume in 1 second/forced volume vital capacity < 0.70 that need clarification.View original paper by Sorino and colleagues.

  15. A possible "grinder" from Tell Arbid, Syria.

    Science.gov (United States)

    Pitre, Mindy C; Koliński, Rafał; Sołtysiak, Arkadiusz

    2017-08-17

    Cereal grinding has been practiced in Mesopotamia since the Upper Palaeolithic. While evidence of cereal grinding is clear from the archaeological and textual records, what remains unclear is whether the activity leaves signs on the skeleton in the form of markers of occupational stress (MOS). A particular constellation of MOS (e.g., osteoarthritis, traumatic injuries, and accessory articular facets) has previously been used to infer the habitual grinding of grain. These same MOS were recently observed in the skeleton of a female discovered in the Middle Bronze Age cemetery at Tell Arbid, NE Syria. Through differential diagnosis our results suggest that it remains problematic to identify grain-processing activities from the skeleton, even when a bioarchaeological approach is carried out.

  16. Simplified Dynamic Analysis of Grinders Spindle Node

    Science.gov (United States)

    Demec, Peter

    2014-12-01

    The contribution deals with the simplified dynamic analysis of surface grinding machine spindle node. Dynamic analysis is based on the use of the transfer matrix method, which is essentially a matrix form of method of initial parameters. The advantage of the described method, despite the seemingly complex mathematical apparatus, is primarily, that it does not require for solve the problem of costly commercial software using finite element method. All calculations can be made for example in MS Excel, which is advantageous especially in the initial stages of constructing of spindle node for the rapid assessment of the suitability its design. After detailing the entire structure of spindle node is then also necessary to perform the refined dynamic analysis in the environment of FEM, which it requires the necessary skills and experience and it is therefore economically difficult. This work was developed within grant project KEGA No. 023TUKE-4/2012 Creation of a comprehensive educational - teaching material for the article Production technique using a combination of traditional and modern information technology and e-learning.

  17. Research on Cutter Radius Compensation of Stone Bridge Cutting Machine CNC System%石材桥式切割机数控系统的刀补研究

    Institute of Scientific and Technical Information of China (English)

    吴宪福; 刘建群; 许东伟

    2014-01-01

    In order to achieve accurate machining of stone contour,the design of cutter compensation module of different tools is the key technology for developing CNC system. Through the research of the C-function cutter radius compensation algorithm,several kinds of transforming of cutter compensation and its estimating algorithm were briefed,and by combining with the machining character-istics of the stone bridge cutting machine,the cutter radius compensation algorithm of sawing,milling and grinding were designed. By using the hardware structure of PC&motion control card,the stone bridge cutting machine CNC system software was designed and de-veloped with Visual C+ + software. Cutter compensation of sawing,milling and grinding were simulated,and the machining was test-ed in the factory. The results show that the machining of machine is stable,and the cutter radius compensation algorithm can realize automatic tool compensation function.%为了实现对石材轮廓的精确加工,不同刀具的刀补模块设计是开发数控系统的关键技术。通过对C机能刀补算法的研究,简述了刀补转接的几种类型及其判断算法,结合石材桥式切割机的加工特点,对锯刀、铣刀、磨刀的刀补算法进行了设计。采用PC+运动控制卡的硬件结构,以Visual C++作为开发软件,设计了石材桥式切割机的数控系统软件。运行石材桥式切割机的数控系统,对锯刀、铣刀、磨刀刀补进行仿真,并在工厂中进行加工测试。结果表明:该切割机能稳定运行,其刀补算法实现了自动刀具补偿功能。

  18. Effects of Wheel Wear on the Manufacturing Errors of Ball-Nose End Milling Cutter%砂轮磨损对球头立铣刀制造误差的影响研究

    Institute of Scientific and Technical Information of China (English)

    夏文胜; 周兆锋; 成岗; 何林

    2013-01-01

    The ball-nose end milling cutter is an important cutting tool which is used to cut the complicated high-precision curved surface. In the manufacturing process of grinding ball-nose end milling cutter, as the grinding time increased, the wheel will be wear, the edge curve of ball-nose end milling cutter will also change. In the paper, the grinding simulation system and parameters analysis system of rake face of ball-nose end milling cutter was established, the means of Visual Basic, based on SolidWorks software platform. Effects of grinding wheel wear on the edge strip width and edge curve of ball-nose end milling cutter was investigated. The obtained results can provide theoretical guides to the manufacturing process of ball-nose end milling cutter, and provide the guidance for the follow-up to develop the correct error compensation strategy.%球头立铣刀是加工复杂高精度曲面的重要刀具.在磨削加工球头立铣刀的制造过程中,随着磨削时间的增加,砂轮会出现磨损,球头立铣刀的刃形曲线会随之发生变化.文章以SolidWorks为开发平台,基于球头立铣刀前刀面的磨削加工运动关系,利用Visual Basic语言进行二次开发,开发出球头立铣刀前刀面的磨削仿真加工系统和刀具参数分析系统,分析了砂轮磨损对球头立铣刀刃带宽度和刃形曲线的影响.分析结果可为实际加工过程提供理论指导,有助于制定正确的磨削制造工艺,并为后续制定正确误差补偿策略提供重要指导.

  19. Homotopies and the Universal Fixed Point Property

    DEFF Research Database (Denmark)

    Szymik, Markus

    2015-01-01

    A topological space has the fixed point property if every continuous self-map of that space has at least one fixed point. We demonstrate that there are serious restraints imposed by the requirement that there be a choice of fixed points that is continuous whenever the self-map varies continuously...

  20. Fixed Target Collisions at STAR

    Science.gov (United States)

    Meehan, Kathryn C.

    2016-12-01

    The RHIC Beam Energy Scan (BES) program was proposed to look for the turn-off of signatures of the quark gluon plasma (QGP), search for a possible QCD critical point, and study the nature of the phase transition between hadronic and partonic matter. Previous results have been used to claim that the onset of deconfinement occurs at a center-of-mass energy of 7 GeV. Data from lower energies are needed to test if this onset occurs. The goal of the STAR Fixed-Target Program is to extend the collision energy range in BES II to energies that are likely below the onset of deconfinement. Currently, STAR has inserted a gold target into the beam pipe and conducted test runs at center-of-mass energies of 3.9 and 4.5 GeV. Tests have been done with both Au and Al beams. First physics results from a Coulomb potential analysis of Au + Au fixed-target collisions are presented and are found to be consistent with results from previous experiments. Furthermore, the Coulomb potential, which is sensitive to the Z of the projectile and degree of baryonic stopping, will be compared to published results from the AGS.

  1. Utilization of nitrogen fixing trees

    Energy Technology Data Exchange (ETDEWEB)

    Brewbaker, J.L.; Beldt, R. van den; MacDicken, K.; Budowski, G.; Kass, D.C.L.; Russo, R.O.; Escalante, G.; Herrera, R.; Aranguren, J.; Arkcoll, D.B.; Doebereinger, J. (cord.)

    1983-01-01

    Six papers from the symposium are noted. Brewbaker, J.L., Beldt, R. van den, MacDicken, K. Fuelwood uses and properties of nitrogen-fixing trees, pp 193-204, (Refs. 15). Includes a list of 35 nitrogen-fixing trees of high fuelwood value. Budowski, G.; Kass, D.C.L.; Russo, R.O. Leguminous trees for shade, pp 205-222, (Refs. 68). Escalante, G., Herrera, R., Aranguren, J.; Nitrogen fixation in shade trees (Erythrina poeppigiana) in cocoa plantations in northern Venezuela, pp 223-230, (Refs. 13). Arkcoll, D.B.; Some leguminous trees providing useful fruits in the North of Brazil, pp 235-239, (Refs. 13). This paper deals with Parkia platycephala, Pentaclethra macroloba, Swartzia sp., Cassia leiandra, Hymenaea courbaril, dipteryz odorata, Inga edulis, I. macrophylla, and I. cinnamonea. Baggio, A.J.; Possibilities of the use of Gliricidia sepium in agroforestry systems in Brazil, pp 241-243; (Refs. 15). Seiffert, N.F.; Biological nitrogen and protein production of Leucaena cultivars grown to supplement the nutrition of ruminants, pp 245-249, (Refs. 14). Leucaena leucocephala cv. Peru, L. campina grande (L. leucocephala), and L. cunningham (L. leucocephalae) were promising for use as browse by beef cattle in central Brazil.

  2. Complex issues in accounting for fixed assets

    Directory of Open Access Journals (Sweden)

    Mykhaylo Luchko

    2013-11-01

    Full Text Available This paper considers the mentioned complex issues of business fixed assets accounting. The main emphasis in this case refers to the change in value of fixed assets over time. Author studied problems of the regulatory revaluation of fixed assets in accordance with the applicable accounting standards (regulations. Particular attention is paid to the revaluation and impairment of the business fixed assets objects and their recording on accounts. Author analyzed the complex issues in establishing the fair value of fixed assets. Attention is focused on the harmonization of accounting information with tax calculations and reporting provided by the Ukrainian Tax Code. In considering the matter referred to the tax differences (temporary and permanent. Established tax differences in depreciation of fixed assets, impairment amounts and revaluation of fixed assets and accounting entries to them.

  3. Simple fixed functional space maintainer.

    Science.gov (United States)

    Goenka, Puneet; Sarawgi, Aditi; Marwah, Nikhil; Gumber, Parvind; Dutta, Samir

    2014-01-01

    Premature loss of a primary tooth is one of the most common etiology for malocclusion. Space maintainers are employed to prevent this complication. In anterior region, esthetics is an important concern along with function and space management. Fiber-reinforced composite (FRC) retained space maintainer solves all these purposes ef ficiently and ef fectively. In addition, the technique is simple and the appliance is very comfortable inside the oral cavity. Here is a case of premature loss of anterior primary tooth which was replaced by FRC retained esthetic functional space maintainer. The appliance was found to be functioning satisfactorily inside the oral cavity till the last visit (1 Year). How to cite this article: Goenka P, Sarawgi A, Marwah N, Gumber P, Dutta S. Simple Fixed Functional Space Maintainer. Int J Clin Pediatr Dent 2014;7(3):225-228.

  4. Fixed Point and Aperiodic Tilings

    CERN Document Server

    Durand, Bruno; Shen, Alexander

    2008-01-01

    An aperiodic tile set was first constructed by R.Berger while proving the undecidability of the domino problem. It turned out that aperiodic tile sets appear in many topics ranging from logic (the Entscheidungsproblem) to physics (quasicrystals) We present a new construction of an aperiodic tile set that is based on Kleene's fixed-point construction instead of geometric arguments. This construction is similar to J. von Neumann self-reproducing automata; similar ideas were also used by P. Gacs in the context of error-correcting computations. The flexibility of this construction allows us to construct a ``robust'' aperiodic tile set that does not have periodic (or close to periodic) tilings even if we allow some (sparse enough) tiling errors. This property was not known for any of the existing aperiodic tile sets.

  5. Efficient 5-axis NC Milling of Spiral Bevel Gears Using Disc Cutter with Concave End and Its Machining Simulation%弧齿锥齿轮中凹盘铣刀高效数控铣削及仿真

    Institute of Scientific and Technical Information of China (English)

    李更更; 邓效忠; 魏冰阳; 李天兴; 杨建军

    2012-01-01

    In order to solve the small cutting strip width and low machining efficiency problem when spiral bevel gears were NC machined by ball - end cutter,a efficient machining method of 5 - axis NC milling spiral bevel gears by a disc cutter with concave end was presented. Based on the traditional machining theory, spiral bevel gear geometry structure was held. The cutter yaw angle was determined in order to avoid gouge interference. Then the cutter tilt angel was determined according to sculptured surface end -milling theory in order to obtain big cutting strip width. Finally, a spiral bevel gear was NC machined virtually, and the machining method feasibility was verified.%为了解决球头铣刀数控铣削弧齿锥齿轮时切削带宽小、效率低等问题,提出了基于中凹盘铣刀的弧齿锥齿轮五轴数控高效率铣削方法.在掌握弧齿锥齿轮几何构造的基础上,选用刀底带内凹的盘铣刀,先确定刀具侧倾角以避免齿槽底面的过切,再参考端铣刀加工自由曲面的理论确定刀具前倾角,以保证大的切削带宽.弧齿锥齿轮的数控铣削仿真验证了该高效铣削方法的可行性和正确性.

  6. 基于ANSYS Workbench的钢格板剪床刀具优化设计%Optimization Design of Cutter for Steel Gratings Shearing Machine Based on ANSYS Workbench

    Institute of Scientific and Technical Information of China (English)

    孟宾宾; 傅菁菁; 施昱

    2014-01-01

    以钢格板剪床刀具为研究对象,基于ANSYS Workbench软件的优化设计功能,在Design Modeler模块中创建刀具的参数化三维模型,进而利用Design Explorer模块在静力分析的基础上对刀具进行优化设计。通过计算相关参数的敏感性以及输入参数的响应来确定优化方案,设定优化目标,最终计算出优化结果,以达到降低刀具所受应力、减小刀具的宽度和厚度的目的。%Regarding steel gratings shearing machine cutter as the research object .Based on the optimal design func-tion of ANSYS Workbench software , it creates the parametric 3D model in Design Modeler module .By using Design Ex-plorer, it can reach optimal design of cutter on the basis of static analysis .The final optimal program is determined by cal-culating the sensitivity of related parameters and reaction of input parameters .The final result can be calculated by this set-ting object in order to reduce the stress , the width and thickness of cutter .

  7. Fixed Point Actions for Lattice Fermions

    CERN Document Server

    Bietenholz, W

    1994-01-01

    The fixed point actions for Wilson and staggered lattice fermions are determined by iterating renormalization group transformations. In both cases a line of fixed points is found. Some points have very local fixed point actions. They can be used to construct perfect lattice actions for asymptotically free fermionic theories like QCD or the Gross-Neveu model. The local fixed point actions for Wilson fermions break chiral symmetry, while in the staggered case the remnant $U(1)_e \\otimes U(1)_o$ symmetry is preserved. In addition, for Wilson fermions a nonlocal fixed point is found that corresponds to free chiral fermions. The vicinity of this fixed point is studied in the Gross-Neveu model using perturbation theory.

  8. Fixed telephony evolution at CERN

    CERN Document Server

    CERN. Geneva

    2015-01-01

    The heart of CERN’s telephony infrastructure consists of the Alcatel IP-PBX that links CERN’s fixed line phones, Lync softphones and CERN’s GSM subscribers to low-cost local and international telephony services. The PABX infrastructure also supports the emergency “red telephones” in the LHC tunnel and provides vital services for the Fire and Rescue Service and the CERN Control Centre. Although still reliable, the Alcatel hardware is increasingly costly to maintain and looking increasingly outmoded in a market where open source solutions are increasingly dominant. After presenting an overview of the Alcatel PABX and the services it provides, including innovative solutions such as the Closed User Group for our mobile telephony services, we present a possible architecture for a software based system designed to meet tomorrow’s communication needs and describe how the introduction of open-source call routers based on the SIP protocol and Session Border Controllers (SBC) could foster the introduction...

  9. Fixed drug eruptions with modafinil

    Directory of Open Access Journals (Sweden)

    Loknath Ghoshal

    2015-01-01

    Full Text Available Modafinil is a psychostimulant drug, which has been approved by the US Food and Drug Administration for the treatment of narcolepsy associated excessive daytime sleepiness, sleep disorder related to shift work, and obstructive sleep apnea syndrome. However, presently it is being used as a lifestyle medicine; in India, it has been misused as an "over the counter" drug. Modafinil is known to have several cutaneous side effects. Fixed drug eruption (FDE is a distinctive drug induced reaction pattern characterized by recurrence of eruption at the same site of the skin or mucous membrane with repeated systemic administration. Only two case reports exist in the literature describing modafinil induced FDE until date. Here, we report two similar cases. The increasing use of this class of drug amongst the medical personnel might be posing a threat to the proper use and encouraging subsequent abuse. There might be a considerable population using these drugs unaware of the possible adverse effects. Authorities should be more alert regarding the sale and distribution of such medicines.

  10. Fixed Export Costs and Export Behavior

    OpenAIRE

    Castro, Luis; Li, Ben; Keith E. Maskus; Xie, Yiqing

    2014-01-01

    This paper provides a direct test of how fixed export costs and productivity jointly determine firm-level export behavior. Using Chilean data, we construct indices of fixed export costs for each industry-region-year triplet and match them to domestic firms. Our empirical results show that firms facing higher fixed export costs are less likely to export, while those with higher productivity export more. These outcomes are the foundation of the widely-used sorting mechanism in the trade models ...

  11. Fixed-point-like theorems on subspaces

    Directory of Open Access Journals (Sweden)

    Bernard Cornet

    2004-08-01

    Full Text Available We prove a fixed-point-like theorem for multivalued mappings defined on the finite Cartesian product of Grassmannian manifolds and convex sets. Our result generalizes two different kinds of theorems: the fixed-point-like theorem by Hirsch et al. (1990 or Husseini et al. (1990 and the fixed-point theorem by Gale and Mas-Colell (1975 (which generalizes Kakutani's theorem (1941.

  12. Fixed point theorems in spaces and -trees

    Directory of Open Access Journals (Sweden)

    Kirk WA

    2004-01-01

    Full Text Available We show that if is a bounded open set in a complete space , and if is nonexpansive, then always has a fixed point if there exists such that for all . It is also shown that if is a geodesically bounded closed convex subset of a complete -tree with , and if is a continuous mapping for which for some and all , then has a fixed point. It is also noted that a geodesically bounded complete -tree has the fixed point property for continuous mappings. These latter results are used to obtain variants of the classical fixed edge theorem in graph theory.

  13. Fixed Simplex Property for Retractable Complexes

    Directory of Open Access Journals (Sweden)

    Zapart Anna

    2010-01-01

    Full Text Available Abstract Retractable complexes are defined in this paper. It is proved that they have the fixed simplex property for simplicial maps. This implies the theorem of Wallace and the theorem of Rival and Nowakowski for finite trees: every simplicial map transforming vertices of a tree into itself has a fixed vertex or a fixed edge. This also implies the Hell and Nešetřil theorem: any endomorphism of a dismantlable graph fixes some clique. Properties of recursively contractible complexes are examined.

  14. Application of pressure relief and permeability increased by slotting a coal seam with a rotary type cutter working across rock layers

    Institute of Scientific and Technical Information of China (English)

    Shen Chunming; Lin Baiquan; Meng Fanwei; Zhang Qizhi; Zhai Cheng

    2012-01-01

    Pressure relief to increase permeability significantly improves gas extraction efficiency from coal seams.In this paper we report results from simulations using FLAC3D code to analyze changes in coal displacement and stress after special drill slots were formed.We investigated the mechanism of pressure relief and permeability increase in a high-gas and low-permeability coal seam through the modeling of gas flow.This allows the development of the technology.Slotting across rock layers in the coal seam with a rotary type cutter was then applied in the field.The results show that pressure relief and permeability increases from slotting the coal seam can increase the transport and the fracture of the coal.This expands the range of pressure relief from the drilling and increases the exposed area of the seam.The total quantity of gas extracted from slotted bore holes was three times that seen with ordinary drilling.The concentration of gas extracted from the slotted drills was from two to three times that seen using ordinary drills.The gas flow was stable at 80%.Improved permeability and more efficient gas extraction are the result of the slotting.The roadway development rate is increased by 30-50% after gas drainage.This technology diminishes the lag between longwall production and roadway development and effectively prevents coal and gas outburst,which offers the prospect of broad application.

  15. Application of water jet assisted drag bit and pick cutter for the cutting of coal measure rocks. Final technical report. [Tests of combination in different rocks

    Energy Technology Data Exchange (ETDEWEB)

    Ropchan, D.; Wang, F.D.; Wolgamott, J.

    1980-04-01

    A laboratory investigation was made of the effects of high pressure water jets on the cutting forces of drag bit cutters in sedimentary rocks. A hard and soft sandstone, shale and limestone were tested with commercially obtainable conical and plow type drag bits on the EMI linear cutting machine. About 1200 cuts were made at different bit penetration, jet orientation, and water pressure to determine the reduction of cutting forces on the bit from the use of the water jet. Both independent and interactive cutting was used. The greatest reduction in cutting forces were with both of the sandstones; the drag forces were reduced about 30 percent and the normal forces about 60 percent at 5000 psi water pressure with the nozzle behind the bit. The method was less effective in the shale, except at 10,000 psi water pressure the reduction in drag force was about 55 percent. Of the rocks tested, the limestone was least affected by the water jet. The cutting forces for the plow bit showed continuous change with wear so a machined conical bit was used for most of the testing. Tests with the plow bit did show a large reduction in cutting forces by using the water jet with worn bits. An economic analysis of equipping a drag bit tunnel boring machine indicated that the water jet system could reduce costs per foot in sandstone by up to 40 percent.

  16. Ligand field density functional theory calculation of the 4f2→ 4f15d1 transitions in the quantum cutter Cs2KYF6:Pr3+.

    Science.gov (United States)

    Ramanantoanina, Harry; Urland, Werner; Cimpoesu, Fanica; Daul, Claude

    2013-09-07

    Herein we present a Ligand Field Density Functional Theory (LFDFT) based methodology for the analysis of the 4f(n)→ 4f(n-1)5d(1) transitions in rare earth compounds and apply it for the characterization of the 4f(2)→ 4f(1)5d(1) transitions in the quantum cutter Cs2KYF6:Pr(3+) with the elpasolite structure type. The methodological advances are relevant for the analysis and prospection of materials acting as phosphors in light-emitting diodes. The positions of the zero-phonon energy corresponding to the states of the electron configurations 4f(2) and 4f(1)5d(1) are calculated, where the praseodymium ion may occupy either the Cs(+)-, K(+)- or the Y(3+)-site, and are compared with available experimental data. The theoretical results show that the occupation of the three undistorted sites allows a quantum-cutting process. However size effects due to the difference between the ionic radii of Pr(3+) and K(+) as well as Cs(+) lead to the distortion of the K(+)- and the Cs(+)-site, which finally exclude these sites for quantum-cutting. A detailed discussion about the origin of this distortion is also described.

  17. Dynamic Stress Measurement and Analysis for the Top-cutter Machine of Cotton%棉花打顶机动应力测试及分析

    Institute of Scientific and Technical Information of China (English)

    徐春梅; 王春耀

    2016-01-01

    应用动态应变测试方法对某棉花打顶机机架和工作部件进行实地动应力测试,通过数据处理以及数据分析,得到了机架及工作部件在工作条件下的应力状态,还进行了主轴强度校核和疲劳分析,为改进车架的设计提供了必要的依据。%The dynamic strain measurement method was used to measure the stress of top⁃cutter machine of cotton under its work⁃ing state in workplace. With data processing and analysis, the stress conditions of the framing and the working parts could be obtained. And the measurement result could be used to analyze the axle’ s fatigue strength and check whether it was safe or not. It provided inte⁃grant basis for the further design of the machine.

  18. Cellulose-Enriched Microbial Communities from Leaf-Cutter Ant (Atta colombica Refuse Dumps Vary in Taxonomic Composition and Degradation Ability.

    Directory of Open Access Journals (Sweden)

    Gina R Lewin

    Full Text Available Deconstruction of the cellulose in plant cell walls is critical for carbon flow through ecosystems and for the production of sustainable cellulosic biofuels. Our understanding of cellulose deconstruction is largely limited to the study of microbes in isolation, but in nature, this process is driven by microbes within complex communities. In Neotropical forests, microbes in leaf-cutter ant refuse dumps are important for carbon turnover. These dumps consist of decaying plant material and a diverse bacterial community, as shown here by electron microscopy. To study the portion of the community capable of cellulose degradation, we performed enrichments on cellulose using material from five Atta colombica refuse dumps. The ability of enriched communities to degrade cellulose varied significantly across refuse dumps. 16S rRNA gene amplicon sequencing of enriched samples identified that the community structure correlated with refuse dump and with degradation ability. Overall, samples were dominated by Bacteroidetes, Gammaproteobacteria, and Betaproteobacteria. Half of abundant operational taxonomic units (OTUs across samples were classified within genera containing known cellulose degraders, including Acidovorax, the most abundant OTU detected across samples, which was positively correlated with cellulolytic ability. A representative Acidovorax strain was isolated, but did not grow on cellulose alone. Phenotypic and compositional analyses of enrichment cultures, such as those presented here, help link community composition with cellulolytic ability and provide insight into the complexity of community-based cellulose degradation.

  19. Factors influencing bonding fixed restorations

    Directory of Open Access Journals (Sweden)

    Medić Vesna

    2008-01-01

    Full Text Available INTRODUCTION Crown displacement often occurs because the features of tooth preparations do not counteract the forces directed against restorations. OBJECTIVE The purpose of this study was to evaluate the effect of preparation designs on retention and resistance of fixed restorations. METHOD The study was performed on 64 differently sized stainless steel dies. Also, caps which were used for evaluated retention were made of stainless steel for each die. After cementing the caps on experimental dies, measuring of necessary tensile forces to separate cemented caps from dies was done. Caps, which were made of a silver-palladium alloy with a slope of 60° to the longitudinal axis formed on the occlusal surface, were used for evaluating resistance. A sudden drop in load pressure recorded by the test machine indicated failure for that cap. RESULTS A significant difference was found between the tensile force required to remove the caps from the dies with different length (p<0.05 and different taper (p<0.01. The greatest retentive strengths (2579.2 N and 2989.8 N were noticed in experimental dies with the greatest length and smallest taper. No statistically significant (p>0.05 differences were found between tensile loads for caps cemented on dies with different diameter. Although there was an apparent slight increase in resistance values for caps on dies with smaller tapers, the increase in resistance for those preparation designs was not statistically significant. There was a significant difference among the resistance values for caps on dies with different length (p<0.01 and diameter (p<0.05. CONCLUSION In the light of the results obtained, it could be reasonably concluded that retention and resistance of the restoration is in inverse proportion to convergence angle of the prepared teeth. But, at a constant convergence angle, retention and resistance increase with rising length and diameter.

  20. Ciprofloxacin induced fixed drug eruption

    Directory of Open Access Journals (Sweden)

    M. Ravishankar

    2014-12-01

    Full Text Available Fixed drug eruption (FDE is a clinical entity occurring in the same site or sites each time the drug is administered. Acute lesions appear as sharply marginated erythematous plaques, which are usually found on lips, genitalia, abdomen, and legs. The eruptions usually occur within hours of administration of the offending agent and resolves spontaneously without scarring after few weeks of onset. Most common drugs causing FDE are sulfonamides, tetracyclines, salicylates, barbiturates, doxycycline, fluconazole, clarithromycin, etc. Ciprofloxacin, a widely used fluoroquinolone antimicrobial, induces cutaneous adverse drug reactions (ADRs in about 1-2% of treated patients. Urticaria, angioedema, maculopapular exanthems, and photosensitivity are the most frequently documented cutaneous adverse reactions. In this case report, the patient soon after taking ciprofloxacin tablets, developed itching in the lips, palms and in scrotal region. On continuing the treatment, the next day he developed fluid filled lesions over palm, knuckle, and hyperpigmentation. He gives a history of severe itching and rashes in scrotal region. He gives a history of similar complaints in the previous month after taking ciprofloxacin medication. There was no history of intake of any other medication. On examination, bullous lesions and pustules in finger webs, hyperpigmentation on knuckles, and scrotal erosions were seen. In the present case report, the patient presented with FDE immediately after oral administration of ciprofloxacin and got completely cured after stopping the drug and taking adequate treatment. According to the Naranjo's ADR probability scale (score=8, this ADR is categorized as a and ldquo;probable and rdquo; reaction to the drug. [Int J Basic Clin Pharmacol 2014; 3(6.000: 1096-1097

  1. Fixed Point Curve for Weakly Inward Contractions and Approximate Fixed Point Property

    Institute of Scientific and Technical Information of China (English)

    P. Riyas; K. T. Ravindran

    2013-01-01

    In this paper, we discuss the concept of fixed point curve for linear interpo-lations of weakly inward contractions and establish necessary condition for a nonex-pansive mapping to have approximate fixed point property.

  2. VAT and Fixed Establishment : Mysteries Solved?

    NARCIS (Netherlands)

    M.L. Schippers (Martijn); Boender, J.M.B.

    2015-01-01

    markdownabstractThe Sixth Value Added Tax (VAT) Directive introduced the concept of the fixed establishment in VAT. For a long time, the criteria for classifying activities as a fixed establishment seemed relatively clear. However the introduction in 2011 of the VAT Implementing Regulation3

  3. Approximate Equilibrium Problems and Fixed Points

    Directory of Open Access Journals (Sweden)

    H. Mazaheri

    2013-01-01

    Full Text Available We find a common element of the set of fixed points of a map and the set of solutions of an approximate equilibrium problem in a Hilbert space. Then, we show that one of the sequences weakly converges. Also we obtain some theorems about equilibrium problems and fixed points.

  4. On computing fixed points for generalized sandpiles

    OpenAIRE

    Formenti, Enrico; Masson, Benoît

    2004-01-01

    Presented at DMCS 2004 (Turku, FINLAND). Long version with proofs published in International Journal of Unconventional Computing, 2006; International audience; We prove fixed points results for sandpiles starting with arbitrary initial conditions. We give an effective algorithm for computing such fixed points, and we refine it in the particular case of SPM.

  5. Fixed-Response Questions with a Difference.

    Science.gov (United States)

    Johnstone, Alex H.; Ambusaidi, Abdullah

    2002-01-01

    Offers three types of fixed-response questions that are designed to overcome drawbacks appearing in the conventional forms of fixed-response questions such as not allowing the examiner to investigate reasoning, background, or prevent guessing. (Contains 14 references.) (Author/YDS)

  6. Approximate fixed point of Reich operator

    Directory of Open Access Journals (Sweden)

    M. Saha

    2013-01-01

    Full Text Available In the present paper, we study the existence of approximate fixed pointfor Reich operator together with the property that the ε-fixed points are concentrated in a set with the diameter tends to zero if ε $to$ > 0.

  7. Stabilising springs for fixed lingual retainer.

    Science.gov (United States)

    Karthikeyan, M K; Ramachandraprabhakar; Saravanan, R; Rajvikram, N; Kuppuchamy

    2013-11-01

    Most treated malocclusion needs fixed lingual retention. To stabilise fixed lingual retainer in the exact location needs proper stabilisation. Proper stabilization requires a holding spring. This Stabilising Spring should be easy to fabricate and help the clinician to stabilise the retainer quickly and save the chair side time. More over it should not irritate the mucosa and should be easy to insert and remove.

  8. Magnetic Fixed Points and Emergent Supersymmetry

    DEFF Research Database (Denmark)

    Antipin, Oleg; Mojaza, Matin; Pica, Claudio;

    2013-01-01

    We establish in perturbation theory the existence of fixed points along the renormalization group flow for QCD with an adjoint Weyl fermion and scalar matter reminiscent of magnetic duals of QCD [1-3]. We classify the fixed points by analyzing their basin of attraction. We discover that among the...

  9. Fixed-Response Questions with a Difference.

    Science.gov (United States)

    Johnstone, Alex H.; Ambusaidi, Abdullah

    2002-01-01

    Offers three types of fixed-response questions that are designed to overcome drawbacks appearing in the conventional forms of fixed-response questions such as not allowing the examiner to investigate reasoning, background, or prevent guessing. (Contains 14 references.) (Author/YDS)

  10. Fixed points of occasionally weakly biased mappings

    Directory of Open Access Journals (Sweden)

    Y. Mahendra Singh, M. R. Singh

    2012-09-01

    Full Text Available Common fixed point results due to Pant et al. [Pant et al., Weak reciprocal continuity and fixed point theorems, Ann Univ Ferrara, 57(1, 181-190 (2011] are extended to a class of non commuting operators called occasionally weakly biased pair[ N. Hussain, M. A. Khamsi A. Latif, Commonfixed points for JH-operators and occasionally weakly biased pairs under relaxed conditions, Nonlinear Analysis, 74, 2133-2140 (2011]. We also provideillustrative examples to justify the improvements. Abstract. Common fixed point results due to Pant et al. [Pant et al., Weakreciprocal continuity and fixed point theorems, Ann Univ Ferrara, 57(1, 181-190 (2011] are extended to a class of non commuting operators called occasionally weakly biased pair[ N. Hussain, M. A. Khamsi A. Latif, Common fixed points for JH-operators and occasionally weakly biased pairs under relaxed conditions, Nonlinear Analysis, 74, 2133-2140 (2011]. We also provide illustrative examples to justify the improvements.

  11. The price of fixed income market volatility

    CERN Document Server

    Mele, Antonio

    2015-01-01

    Fixed income volatility and equity volatility evolve heterogeneously over time, co-moving disproportionately during periods of global imbalances and each reacting to events of different nature. While the methodology for options-based "model-free" pricing of equity volatility has been known for some time, little is known about analogous methodologies for pricing various fixed income volatilities. This book fills this gap and provides a unified evaluation framework of fixed income volatility while dealing with disparate markets such as interest-rate swaps, government bonds, time-deposits and credit. It develops model-free, forward looking indexes of fixed-income volatility that match different quoting conventions across various markets, and uncovers subtle yet important pitfalls arising from naïve superimpositions of the standard equity volatility methodology when pricing various fixed income volatilities. The ultimate goal of the authors´ efforts is to make interest rate volatility standardization a valuable...

  12. Magnetic Fixed Points and Emergent Supersymmetry

    CERN Document Server

    Antipin, Oleg; Pica, Claudio; Sannino, Francesco

    2011-01-01

    We establish the existence of fixed points for certain gauge theories candidate to be magnetic duals of QCD with one adjoint Weyl fermion. In the perturbative regime of the magnetic theory the existence of a very large number of fixed points is unveiled. We classify them by analyzing their basin of attraction. The existence of several nonsupersymmetric fixed points for the magnetic gauge theory lends further support towards the existence of gauge-gauge duality beyond supersymmetry. We also discover that among these very many fixed points there are supersymmetric ones emerging from a generic nonsupersymmetric renormalization group flow. We therefore conclude that supersymmetry naturally emerges as a fixed point theory from a nonsupersymmetric Lagrangian without the need for fine-tuning of the bare couplings. Our results suggest that supersymmetry can be viewed as an emergent phenomenon in field theory. In particular there should be no need for fine-tuning the bare couplings when performing Lattice simulations ...

  13. Fixed-point adiabatic quantum search

    Science.gov (United States)

    Dalzell, Alexander M.; Yoder, Theodore J.; Chuang, Isaac L.

    2017-01-01

    Fixed-point quantum search algorithms succeed at finding one of M target items among N total items even when the run time of the algorithm is longer than necessary. While the famous Grover's algorithm can search quadratically faster than a classical computer, it lacks the fixed-point property—the fraction of target items must be known precisely to know when to terminate the algorithm. Recently, Yoder, Low, and Chuang [Phys. Rev. Lett. 113, 210501 (2014), 10.1103/PhysRevLett.113.210501] gave an optimal gate-model search algorithm with the fixed-point property. Previously, it had been discovered by Roland and Cerf [Phys. Rev. A 65, 042308 (2002), 10.1103/PhysRevA.65.042308] that an adiabatic quantum algorithm, operating by continuously varying a Hamiltonian, can reproduce the quadratic speedup of gate-model Grover search. We ask, can an adiabatic algorithm also reproduce the fixed-point property? We show that the answer depends on what interpolation schedule is used, so as in the gate model, there are both fixed-point and non-fixed-point versions of adiabatic search, only some of which attain the quadratic quantum speedup. Guided by geometric intuition on the Bloch sphere, we rigorously justify our claims with an explicit upper bound on the error in the adiabatic approximation. We also show that the fixed-point adiabatic search algorithm can be simulated in the gate model with neither loss of the quadratic Grover speedup nor of the fixed-point property. Finally, we discuss natural uses of fixed-point algorithms such as preparation of a relatively prime state and oblivious amplitude amplification.

  14. About Applications of the Fixed Point Theory

    Directory of Open Access Journals (Sweden)

    Bucur Amelia

    2017-06-01

    Full Text Available The fixed point theory is essential to various theoretical and applied fields, such as variational and linear inequalities, the approximation theory, nonlinear analysis, integral and differential equations and inclusions, the dynamic systems theory, mathematics of fractals, mathematical economics (game theory, equilibrium problems, and optimisation problems and mathematical modelling. This paper presents a few benchmarks regarding the applications of the fixed point theory. This paper also debates if the results of the fixed point theory can be applied to the mathematical modelling of quality.

  15. [FIXED COMBINATION ATORVASTATIN-EZETIMIBE (ATOZET®)].

    Science.gov (United States)

    Scheen, A J

    2016-01-01

    Cardiovascular prevention in subjects at high or very high risk requires a drastic reduction in LDL cholesterol according to the concept "the lower, the better". The combination of an inhibitor of cholesterol synthesis and a selective inhibitor of intestinal absorption results in a complementary and synergistic LDL-lowering activity. Besides a first fixed combination ezetimibe-simvastatin (Inegy®), a new fixed combination is presented, Atozet® that combines atorvastatin and ezetimibe. Because atorvastatin is more potent than simvastatin, this novel fixed combination should facilitate reaching therapeutic goals in terms of LDL cholesterol amongst patients with severe hypercholesterolaemia and/or at high or very high cardiovascular risk.

  16. Imaginary fixed points can be physical.

    Science.gov (United States)

    Zhong, Fan

    2012-08-01

    It has been proposed that a first-order phase transition driven to happen in the metastable region exhibits scaling and universality near an instability point controlled by an instability fixed point of a φ(3) theory. However, this fixed point has an imaginary value and the renormalization-group flow of the φ(3) coupling diverges at a finite scale. Here combining a momentum-space RG analysis and a nucleation theory near the spinodal point, we show that imaginary rather than real values are physical counterintuitively and thus the imaginary fixed point does control the scaling.

  17. Identifying the "demon whale-biter": Patterns of scarring on large whales attributed to a cookie-cutter shark Isistius sp.

    Science.gov (United States)

    Best, Peter B; Photopoulou, Theoni

    2016-01-01

    The presence of crater-like wounds on cetaceans and other large marine vertebrates and invertebrates has been attributed to various organisms. We review the evidence for the identity of the biting agent responsible for crater wounds on large whales, using data collected from sei (Balaenoptera borealis), fin (B. physalus), inshore and offshore Bryde's (B. brydeii sp) and sperm whales (Physeter macrocephalus) examined at the Donkergat whaling station, Saldanha Bay, South Africa between March and October 1963. We then analyse the intensity and trends in its predation on large whales. Despite the scarcity of local records, we conclude that a cookie-cutter shark Isistius sp is the most likely candidate. We make inferences about the trends in (1) total counts of unhealed bitemarks, and (2) the proportion of unhealed bitemarks that were recent. We use day of the year; reproductive class, social grouping or sex; depth interval and body length as candidate covariates. The models with highest support for total counts of unhealed bitemarks involve the day of the year in all species. Depth was an important predictor in all species except offshore Bryde's whales. Models for the proportion of recent bites were only informative for sei and fin whales. We conclude that temporal scarring patterns support what is currently hypothesized about the distribution and movements of these whale species, given that Isistius does not occur in the Antarctic and has an oceanic habitat. The incidence of fresh bites confirms the presence of Isistius in the region. The lower numbers of unhealed bites on medium-sized sperm whales suggests that this group spends more time outside the area in which bites are incurred, providing a clue to one of the biggest gaps in our understanding of the movements of mature and maturing sperm males.

  18. Identifying the “demon whale-biter”: Patterns of scarring on large whales attributed to a cookie-cutter shark Isistius sp

    Science.gov (United States)

    Photopoulou, Theoni

    2016-01-01

    The presence of crater-like wounds on cetaceans and other large marine vertebrates and invertebrates has been attributed to various organisms. We review the evidence for the identity of the biting agent responsible for crater wounds on large whales, using data collected from sei (Balaenoptera borealis), fin (B. physalus), inshore and offshore Bryde’s (B. brydeii sp) and sperm whales (Physeter macrocephalus) examined at the Donkergat whaling station, Saldanha Bay, South Africa between March and October 1963. We then analyse the intensity and trends in its predation on large whales. Despite the scarcity of local records, we conclude that a cookie-cutter shark Isistius sp is the most likely candidate. We make inferences about the trends in (1) total counts of unhealed bitemarks, and (2) the proportion of unhealed bitemarks that were recent. We use day of the year; reproductive class, social grouping or sex; depth interval and body length as candidate covariates. The models with highest support for total counts of unhealed bitemarks involve the day of the year in all species. Depth was an important predictor in all species except offshore Bryde’s whales. Models for the proportion of recent bites were only informative for sei and fin whales. We conclude that temporal scarring patterns support what is currently hypothesized about the distribution and movements of these whale species, given that Isistius does not occur in the Antarctic and has an oceanic habitat. The incidence of fresh bites confirms the presence of Isistius in the region. The lower numbers of unhealed bites on medium-sized sperm whales suggests that this group spends more time outside the area in which bites are incurred, providing a clue to one of the biggest gaps in our understanding of the movements of mature and maturing sperm males. PMID:27055057

  19. The Study on Machining of Nano-TiN Modified Cermets Cutters based on FEM%基于FEM的纳米TiN改性金属陶瓷刀具的切削性能研究

    Institute of Scientific and Technical Information of China (English)

    何光春

    2011-01-01

    In this paper, nano-TiN modified TiC-based cermets cutters are taken as object investigated.Based on large deformation-strain, increment theory and Lagrangian equation, to establish machining finite element model of Cochcroft & Latham fracture and Archard wear rule. And AISI 1045 steel is used to simulate the cutting process. And obtain the dominating force/temperature/wear graph of nano-TiN modified cermets cutter by changing rake angle, the simulated results is comparatively in agreement with relevant machining theory. And the wear mechanism is analyzed in brief by combining SEM. This study may be able to develop new way for the coming new cutter materials, to expect to aim to shorten researched cycle and lower the cost.%文章以纳米TiN改性金属陶瓷刀具作为研究对象.基于大变形-大应变、增量理论及拉格朗日算法,建立了Cockcroft&Latham断裂分离及磨损准则的有限元模型,并对AISI1045钢进行切削加工模拟.改变刀具角度,得到不同角度纳米TiN改性金属陶瓷刀具切削过程中的主切削力、温度及后刀面磨损变化曲线,模拟结果与相关切削理论比较吻合.结合刀具磨损SEM形貌,简要分析了此刀具磨损机理.文章的研究能够为后期新型刀具材料的研究开辟了新路径,以期到达缩短研制周期,降低成本的目的.

  20. NEW TYPE ANNULAR CUTTER FORMATION SIMULATION AND GREY RELATION ANALYSIS ON ITS INFLUENCE FACTORS%新型环形切割器成型仿真及影响因素灰关联分析

    Institute of Scientific and Technical Information of China (English)

    吴国东; 贾伟; 米强; 王志军

    2012-01-01

    An annular liner whose thickness was variational and whose cross section was arc-cone shape was proposed. The non-linear finite element software was used to complete the numerical simulation of the arc-cone liner forming annular cutter under explosion loading. The formations for annular cutters on 16 kinds of arc-cone lines with different parameters were simulated by the non-linear finite element software, grey relation analysis for different factors was conducted by grey theory. The result showed that radial ve-locity difference between inner and outer walls of the liner could be reduced through reasonable adjustment its thickness and the designed liner was able to form annular EFP with vertical downward direction. The prime factors which influenced the penetration performance of annular cutters were curvature radius and cone angle.%提出一种截面呈弧锥结合形状的变壁厚环形药型罩结构,应用非线性有限元软件完成了爆炸载荷下弧锥结合罩形成环形切割器的数值模拟.对16种不同参数组合下的环形切割器成型情况进行了仿真,并基于灰色理论对各影响因素进行了灰关联分析.结果表明,合理调节药型罩壁厚能有效地降低内外罩径向速度差,获得竖直向下的环形EFP;影响环形切割器侵彻性能的最主要因素是圆弧曲率半径和锥角.

  1. 球头铣刀曲面加工的刀具切触区域解析建模%Analytical Modeling of Cutter Engagement Regions in Ball-end Milling of Curved Surface

    Institute of Scientific and Technical Information of China (English)

    王亮; 王敏杰; 魏兆成; 王升福

    2012-01-01

    针对球头铣刀三维曲面加工,提出一种刀具切触区域仿真的通用解析模型.采用微分方法,将曲面加工过程离散为一系列连续的微小斜平面稳态加工.以每一小斜面切削过程为研究对象,建立描述刀具进给方向变化的数学模型,针对不同的进给方向并基于空间坐标系旋转变换,提出一组确定刀具切触边界曲线及各边界交点的解析公式,以精确界定刀具切触区域的封闭几何.通过与Z-Map模型的切触区域仿真对比,验证了本文模型的有效性及其精确高效的特点.%This paper presents a generalized analytical model of cutter engagement region simulations for ball - end milling of 3D curved surface. With differential method, the curved surface machining is treated as a series of sequential small inclined surfaces steady state milling. According to the cutting process of each small inclined surface, the mathematical models which are used to describe the variation of cutter feed direction are established. Through space coordinate system rotation transformation, a set of analytic formula of cutter contact boundaries and the intersection points are proposed, in order to exactly determine the closed geometry of engagement regions for different feed directions. The effectiveness and characteristics of accuracy and high - efficiency of the model presented in this paper are verified by the comparison of engagement region simulations with Z - Map model.

  2. Topological fixed point theory of multivalued mappings

    CERN Document Server

    Górniewicz, Lech

    1999-01-01

    This volume presents a broad introduction to the topological fixed point theory of multivalued (set-valued) mappings, treating both classical concepts as well as modern techniques. A variety of up-to-date results is described within a unified framework. Topics covered include the basic theory of set-valued mappings with both convex and nonconvex values, approximation and homological methods in the fixed point theory together with a thorough discussion of various index theories for mappings with a topologically complex structure of values, applications to many fields of mathematics, mathematical economics and related subjects, and the fixed point approach to the theory of ordinary differential inclusions. The work emphasises the topological aspect of the theory, and gives special attention to the Lefschetz and Nielsen fixed point theory for acyclic valued mappings with diverse compactness assumptions via graph approximation and the homological approach. Audience: This work will be of interest to researchers an...

  3. HEALTH INSURANCE: FIXED CONTRIBUTION AND REIMBURSEMENT MAXIMA

    CERN Multimedia

    Human Resources Division

    2001-01-01

    Affected by the salary adjustments on 1 January 2001 and the evolution of the staff members and fellows population, the average reference salary, which is used as an index for fixed contributions and reimbursement maxima, has changed significantly. An adjustment of the amounts of the reimbursement maxima and the fixed contributions is therefore necessary, as from 1 January 2001. Reimbursement maxima The revised reimbursement maxima will appear on the leaflet summarizing the benefits for the year 2001, which will be sent out with the forthcoming issue of the CHIS Bull'. This leaflet will also be available from the divisional secretariats and from the UNIQA office at CERN. Fixed contributions The fixed contributions, applicable to some categories of voluntarily insured persons, are set as follows (amounts in CHF for monthly contributions) : voluntarily insured member of the personnel, with normal health insurance cover : 910.- (was 815.- in 2000) voluntarily insured member of the personnel, with reduced heal...

  4. Gauge Fixing on the Lattice without Ambiguity

    CERN Document Server

    Vink, Jeroen C; 10.1016/0370-2693(92)91372-G

    2009-01-01

    A new gauge fixing condition is discussed, which is (lattice) rotation invariant, has the `smoothness' properties of the Landau gauge but can be efficiently computed and is unambiguous for almost all lattice gauge field configurations.

  5. Anderson Acceleration for Fixed-Point Iterations

    Energy Technology Data Exchange (ETDEWEB)

    Walker, Homer F. [Worcester Polytechnic Institute, MA (United States)

    2015-08-31

    The purpose of this grant was to support research on acceleration methods for fixed-point iterations, with applications to computational frameworks and simulation problems that are of interest to DOE.

  6. Global Wilson-Fisher fixed points

    Science.gov (United States)

    Jüttner, Andreas; Litim, Daniel F.; Marchais, Edouard

    2017-08-01

    The Wilson-Fisher fixed point with O (N) universality in three dimensions is studied using the renormalisation group. It is shown how a combination of analytical and numerical techniques determine global fixed points to leading order in the derivative expansion for real or purely imaginary fields with moderate numerical effort. Universal and non-universal quantities such as scaling exponents and mass ratios are computed, for all N, together with local fixed point coordinates, radii of convergence, and parameters which control the asymptotic behaviour of the effective action. We also explain when and why finite-N results do not converge pointwise towards the exact infinite-N limit. In the regime of purely imaginary fields, a new link between singularities of fixed point effective actions and singularities of their counterparts by Polchinski are established. Implications for other theories are indicated.

  7. Fixed-Point Configurable Hardware Components

    Directory of Open Access Journals (Sweden)

    Rocher Romuald

    2006-01-01

    Full Text Available To reduce the gap between the VLSI technology capability and the designer productivity, design reuse based on IP (intellectual properties is commonly used. In terms of arithmetic accuracy, the generated architecture can generally only be configured through the input and output word lengths. In this paper, a new kind of method to optimize fixed-point arithmetic IP has been proposed. The architecture cost is minimized under accuracy constraints defined by the user. Our approach allows exploring the fixed-point search space and the algorithm-level search space to select the optimized structure and fixed-point specification. To significantly reduce the optimization and design times, analytical models are used for the fixed-point optimization process.

  8. Gravitational fixed points from perturbation theory.

    Science.gov (United States)

    Niedermaier, Max R

    2009-09-04

    The fixed point structure of the renormalization flow in higher derivative gravity is investigated in terms of the background covariant effective action using an operator cutoff that keeps track of powerlike divergences. Spectral positivity of the gauge fixed Hessian can be satisfied upon expansion in the asymptotically free higher derivative coupling. At one-loop order in this coupling strictly positive fixed points are found for the dimensionless Newton constant g(N) and the cosmological constant lambda, which are determined solely by the coefficients of the powerlike divergences. The renormalization flow is asymptotically safe with respect to this fixed point and settles on a lambda(g(N)) trajectory after O(10) units of the renormalization mass scale to accuracy 10(-7).

  9. On hyperbolic fixed points in ultrametric dynamics

    CERN Document Server

    Lindahl, Karl-Olof; 10.1134/S2070046610030052

    2011-01-01

    Let K be a complete ultrametric field. We give lower and upper bounds for the size of linearization discs for power series over K near hyperbolic fixed points. These estimates are maximal in the sense that there exist examples where these estimates give the exact size of the corresponding linearization disc. In particular, at repelling fixed points, the linearization disc is equal to the maximal disc on which the power series is injective.

  10. Fractal Structures For Fixed Mems Capacitors

    KAUST Repository

    Elshurafa, Amro M.

    2014-08-28

    An embodiment of a fractal fixed capacitor comprises a capacitor body in a microelectromechanical system (MEMS) structure. The capacitor body has a first plate with a fractal shape separated by a horizontal distance from a second plate with a fractal shape. The first plate and the second plate are within the same plane. Such a fractal fixed capacitor further comprises a substrate above which the capacitor body is positioned.

  11. Cross Service Fixed-Wing Cost Estimation

    Science.gov (United States)

    2016-05-17

    clarify the costing methods for O&S costs for fixed-wing delivery platforms with the intent of extending the research to other cross- service mission costs...proof-of-concept, this project will concentrate on equating equitable cross- service costs for fixed-wing munitions delivery platforms. The method of... delivery is an essential part of the AoA, especially when the project proposed is the replacement of current missile systems. The services have

  12. Random fixed points and random differential inclusions

    Directory of Open Access Journals (Sweden)

    Nikolaos S. Papageorgiou

    1988-01-01

    Full Text Available In this paper, first, we study random best approximations to random sets, using fixed point techniques, obtaining this way stochastic analogues of earlier deterministic results by Browder-Petryshyn, KyFan and Reich. Then we prove two fixed point theorems for random multifunctions with stochastic domain that satisfy certain tangential conditions. Finally we consider a random differential inclusion with upper semicontinuous orientor field and establish the existence of random solutions.

  13. DNA extraction from formalin-fixed material.

    Science.gov (United States)

    Campos, Paula F; Gilbert, Thomas M P

    2012-01-01

    The principal challenges facing PCR-based analyses of DNA extracted from formalin-fixed materials are fragmentation of the DNA and cross-linked protein-DNA complexes. Here, we present an efficient protocol to extract DNA from formalin-fixed or paraffin-embedded tissues (FFPE). In this protocol, protein-DNA cross-links are reversed using heat and alkali treatment, yielding significantly longer fragments and larger amounts of PCR-amplifiable DNA than standard DNA extraction protocols.

  14. 用反圆环面刀加工变曲率过渡曲面原理%Principle of machining variant with counter curvature blending surfaces torus cutter

    Institute of Scientific and Technical Information of China (English)

    黄魏; 陈志同; 陈五一; 贺英

    2012-01-01

    基于宽行加工理论和广域曲率吻合原则,提出一种利用圆环面内侧作为刀具工作面的反圆环面刀具宽行加工叶片进排气边的新方法.该方法通过优化刀具摆角使具有定母圆半径刀具工作面的包络面充分逼近叶片进排气边曲面,从而使刀具能在给定的精度范围内以最大行宽和最少刀轨行数加工出进排气边.最后,以某型号发动机叶片的进气边为例进行了加工实验.结果表明该方法能够大幅提高进排气边的加工质量,且反圆环面刀的加工行宽比球头刀提高了5倍.%Based on the stripe-width-maximization machining theory and the principle of global curvature fitting, a novel counter torus cutter, which uses the inner surface of torus as the cutting edge, was proposed to machine the leading and trailing edge of a turbine blade. Through optimizing the raw angle of the counter torus cutter with a circular generatrix of given radius, the envelope surface of the tool can closely approximate the leading and trailing edge surface of the turbine blade with variant curvature, which can be machined by maxi- mizing the machining strip width and minimizing the number of tool paths under a given tolerance. An experi- ment to machine the leading and trailing edge of an aero-engine turbine blade was carried out. Results illus- trate that the proposed method could greatly improve the machining quality of the leading and trailing edge, and the machining strip-width using a counter torus cutter is 5 times larger than that using a ball nose cutter.

  15. Precise Point Positioning with Partial Ambiguity Fixing

    Science.gov (United States)

    Li, Pan; Zhang, Xiaohong

    2015-01-01

    Reliable and rapid ambiguity resolution (AR) is the key to fast precise point positioning (PPP). We propose a modified partial ambiguity resolution (PAR) method, in which an elevation and standard deviation criterion are first used to remove the low-precision ambiguity estimates for AR. Subsequently the success rate and ratio-test are simultaneously used in an iterative process to increase the possibility of finding a subset of decorrelated ambiguities which can be fixed with high confidence. One can apply the proposed PAR method to try to achieve an ambiguity-fixed solution when full ambiguity resolution (FAR) fails. We validate this method using data from 450 stations during DOY 021 to 027, 2012. Results demonstrate the proposed PAR method can significantly shorten the time to first fix (TTFF) and increase the fixing rate. Compared with FAR, the average TTFF for PAR is reduced by 14.9% for static PPP and 15.1% for kinematic PPP. Besides, using the PAR method, the average fixing rate can be increased from 83.5% to 98.2% for static PPP, from 80.1% to 95.2% for kinematic PPP respectively. Kinematic PPP accuracy with PAR can also be significantly improved, compared to that with FAR, due to a higher fixing rate. PMID:26067196

  16. Fixed points of symplectic periodic flows

    CERN Document Server

    Pelayo, Alvaro

    2010-01-01

    The study of fixed points is a classical subject in geometry and dynamics. If the circle acts in a Hamiltonian fashion on a compact symplectic manifold M, then it is classically known that there are at least 1 + dim(M)/2 fixed points; this follows from Morse theory for the momentum map of the action. In this paper we use Atiyah-Bott-Berline-Vergne (ABBV) localization in equivariant cohomology to prove that this conclusion also holds for symplectic circle actions with non-empty fixed sets, as long as the Chern class map is somewhere injective -- the Chern class map assigns to a fixed point the sum of the action weights at the point. We complement this result with less sharp lower bounds on the number of fixed points, under no assumptions; from a dynamical systems viewpoint, our results imply that there is no symplectic periodic flow with exactly one or two equilibrium points on a compact manifold of dimension at least eight.

  17. Inadvertent tooth movement with fixed lingual retainers.

    Science.gov (United States)

    Shaughnessy, Timothy G; Proffit, William R; Samara, Said A

    2016-02-01

    Fixed retainers are effective in maintaining the alignment of the anterior teeth more than 90% of the time, but they can produce inadvertent tooth movement that in the most severe instances requires orthodontic retreatment managed with a periodontist. This is different from relapse into crowding when a fixed retainer is lost. These problems arise when the retainer breaks but remains bonded to some or all teeth, or when an intact retainer is distorted by function or was not passive when bonded. In both instances, torque of the affected teeth is the predominant outcome. A fixed retainer made with dead soft wire is the least likely to create torque problems but is the most likely to break. Highly flexible twist wires bonded to all the teeth appear to be the most likely to produce inadvertent tooth movement, but this also can occur with stiffer wires bonded only to the canines. Orthodontists, general dentists, and patients should be aware of possible problems with fixed retainers, especially those with all teeth bonded, because the patient might not notice partial debonding. Regular observations of patients wearing fixed retainers by orthodontists in the short term and family dentists in the long term are needed.

  18. The computation of fixed points and applications

    CERN Document Server

    Todd, Michael J

    1976-01-01

    Fixed-point algorithms have diverse applications in economics, optimization, game theory and the numerical solution of boundary-value problems. Since Scarf's pioneering work [56,57] on obtaining approximate fixed points of continuous mappings, a great deal of research has been done in extending the applicability and improving the efficiency of fixed-point methods. Much of this work is available only in research papers, although Scarf's book [58] gives a remarkably clear exposition of the power of fixed-point methods. However, the algorithms described by Scarf have been super~eded by the more sophisticated restart and homotopy techniques of Merrill [~8,~9] and Eaves and Saigal [1~,16]. To understand the more efficient algorithms one must become familiar with the notions of triangulation and simplicial approxi- tion, whereas Scarf stresses the concept of primitive set. These notes are intended to introduce to a wider audience the most recent fixed-point methods and their applications. Our approach is therefore ...

  19. Au Fixed Point Development at NRC

    Science.gov (United States)

    Dedyulin, S. N.; Gotoh, M.; Todd, A. D. W.

    2017-04-01

    Two Au fixed points filled using metal of different nominal purities in carbon crucibles have been developed at the National Research Council Canada (NRC). The primary motivation behind this project was to provide the means for direct thermocouple calibrations at the Au freezing point (1064.18°C). Using a Au fixed point filled with the metal of maximum available purity [99.9997 % pure according to glow discharge mass spectroscopy (GDMS)], multiple freezing plateaus were measured in a commercial high-temperature furnace. Four Pt/Pd thermocouples constructed and calibrated in-house were used to measure the freezing plateaus. From the calibration at Sn, Zn, Al and Ag fixed points, the linear deviation function from the NIST-IMGC reference function (IEC 62460:2008 Standard) was determined and extrapolated to the freezing temperature of Au. For all the Pt/Pd thermocouples used in this study, the measured EMF values agree with the extrapolated values within expanded uncertainty, thus substantiating the use of 99.9997 % pure Au fixed point cell for thermocouple calibrations at NRC. Using the Au fixed point filled with metal of lower purity (99.99 % pure according to GDMS), the effect of impurities on the Au freezing temperature measured with Pt/Pd thermocouple was further investigated.

  20. Fixed point theory in metric type spaces

    CERN Document Server

    Agarwal, Ravi P; O’Regan, Donal; Roldán-López-de-Hierro, Antonio Francisco

    2015-01-01

    Written by a team of leading experts in the field, this volume presents a self-contained account of the theory, techniques and results in metric type spaces (in particular in G-metric spaces); that is, the text approaches this important area of fixed point analysis beginning from the basic ideas of metric space topology. The text is structured so that it leads the reader from preliminaries and historical notes on metric spaces (in particular G-metric spaces) and on mappings, to Banach type contraction theorems in metric type spaces, fixed point theory in partially ordered G-metric spaces, fixed point theory for expansive mappings in metric type spaces, generalizations, present results and techniques in a very general abstract setting and framework. Fixed point theory is one of the major research areas in nonlinear analysis. This is partly due to the fact that in many real world problems fixed point theory is the basic mathematical tool used to establish the existence of solutions to problems which arise natur...

  1. Solutions to the scrap iron problem around the scrap cutter in trimming die%修边模废料切刀产生铁屑的解决方法

    Institute of Scientific and Technical Information of China (English)

    周厚保; 段彦宾

    2015-01-01

    The reason of scrap iron happening in the trimming die for automobile outer pan⁃el was analyzed. The external, floating and compression type scrap cutter without produc⁃ing scrap iron were respectively presented in terms of the structure principle, design points, application range and the advantages and disadvantages, in which the scrap iron problem around the scrap cutter in the trimming die was resolved.%分析了汽车外覆盖件修边模产生铁屑的原因,分别介绍了不产生铁屑的外置式废料切刀、浮动式废料切刀和压缩式废料切刀的结构原理、设计要点、适用范围以及优缺点,解决了修边模废料切刀位置产生铁屑的问题,对汽车外覆盖件修边类模具设计具有一定的参考作用。

  2. 一种改进 Smith 预估绞吸挖泥船产量控制方法研究%Research of an Improved Smith Production Control Method for Cutter Suction Dredger

    Institute of Scientific and Technical Information of China (English)

    张德新; 蒋爽; 李志刚

    2015-01-01

    A cutter suction dredger experiment stand is the subject of this paper.The traditional Smith pre-dictor control method is improved and a fuzzy Smith pre-dictor control method characterized by parameter identi-fication is proposed.With the improved Smith method, the parameters of predictor can rapidly track and con-verge to the parameters of the actual object.Simulation results show that this scheme can enhance the robust-ness and stability of the control system and overcome the shortcomings of the traditional Smith predictor.This re-search can be used as a reference for the lateral move-ment automation control of cutter suction dredger.%以绞吸挖泥船模型实验台为研究对象,改进传统 Smith 预估器,提出一种参数辨识的模糊Smith 预估控制方法,改进后的 Smith 方法能使预估器的参数迅速跟踪并收敛于实际对象参数。仿真结果表明,该方案增强了系统的鲁棒性和适应性,克服了传统 Smith 预估器的缺点,对绞吸挖泥船横移自动化研究具有参考价值。

  3. Use of CYPRES™ cutters with a Kevlar clamp band for hold-down and release of the Icarus De-Orbit Sail payload on TechDemoSat-1

    Science.gov (United States)

    Kingston, J.; Hobbs, S.; Roberts, P.; Juanes-Vallejo, C.; Robinson, F.; Sewell, R.; Snapir, B.; Llop, J. Virgili; Patel, M.

    2014-07-01

    TechDemoSat-1 is a UK-funded technology demonstration satellite, carrying 8 payloads provided by UK organisations, which is due to be launched in the first quarter of 2014. Cranfield University has supplied a De-Orbit Sail (DOS) payload to allow the mission to comply with end-of-life debris mitigation guidelines. The payload provides a passive, simple, and low-cost means of mitigating debris proliferation in Low Earth Orbit, by enhancing spacecraft aerodynamic drag at end-of-life and reducing time to natural orbital decay and re-entry. This paper describes the use of small commercial electro-explosive devices (EEDs), produced for use as parachute tether-cutters in reserve chute deployment systems, as low-cost but high-reliability release mechanisms for space applications. A testing campaign, including thermal vacuum and mechanical vibration, is described, which demonstrates the suitability of these CYPRES™ cutters, with a flexible Kevlar clamp band, for use as a hold-down and release mechanism (HDRM) for a deployable de-orbit sail. The HDRM is designed to be three-failure-tolerant, highly reliable, yet simple and low-cost.

  4. 基于包络理论新构形插齿刀凸曲前刀面数学建模%Mathematical Model Based on Envelope Theory of Complicated Curved Rake Face of New Profile Shaper Cutter

    Institute of Scientific and Technical Information of China (English)

    段爱杰; 席爱婷; 张文涛

    2012-01-01

    提出一种以异形凸曲前刀面代替传统锥面前刀面的硬质合金插齿刀新构形方法.运用微分几何包络理论建立了新构形插齿刀凸曲前刀面、侧刃空间曲线数学模型,对插齿刀齿形误差、侧刃前角分布进行分析,并提出新构形插齿刀齿形角修正方法.根据新构形理论设计、制造出具有高齿形精度、抗崩刃的新构形硬质合金插齿刀.%A new profile method of carbide shaper cutter with complicated curved rake face instead of conical rake face is proposed in this paper. The mathematical models of complicated curved rake face and cutting edge, which are based on differential geometry envelope theory, are established. Profile error and rake angle are analyzed. Profile correction method is proposed. The shaper cutter with high profile accuracy and high anti - cracked ability is designed and manufactured according to the new profile theory.

  5. 基于可视化编程的往复式切割器工作特性分析%Operation performance analysis of reciprocating cutter based on visual programming

    Institute of Scientific and Technical Information of China (English)

    向阳; 罗锡文; 曾山; 臧英; 杨文武

    2015-01-01

    Cutting diagram is an important means of performance analysis of reciprocating cutter. The evaluation of working performance of reciprocating cutter principally depends on the size of 3 featured areas (repeated cutting area, area failing to cut and once cutting area), which can be observed from the cutting diagram. Drawing cutting diagram by the traditional manual tracing method has the disadvantages of low efficiency and imprecise result. Meanwhile the system of cutting diagram drawing and analyzing which is based on the MATLAB and other homemade programs cannot carry on the continuous analysis of parameter. Aiming at the inconvenience of the traditional methods, a cutting diagram analytic system was developed based on visualization platform. This paper took the standard ordinary I type reciprocating cutter as main research object, performed the kinematic analysis to cutting blade and obtained the moving-track curve of featured points. Method to calculate the 3 featured areas was deduced based on the kinematic analysis of the cutting blade. Moreover, 3 special situations which may happen during the calculation process were analyzed, and the respective solution for each situation was proposed. The software was developed based on VISUAL STUDIO 2008. The main interface of this system mainly consists of cutter parameter configuration zone, working property feature analyzing zone and cutting diagram drawing zone. After inputting the cutting parameter by user, system can draw corresponding cutting diagram and calculate the area of featured areas. The drawing of cutting diagram uses Picturebox control and GDI+ (graphics device interface plus) technology, and it can carry on the coordinate conversion to the actual dimension of cutting blade depending on the dimension of drawing zone. In order to adapt the calculation characteristics of computer, it uses the numerical analysis method in calculation process, including obtaining the coordinates of key points through the

  6. Integrated In Situ Sensing and Modeling to Assess Carbon Dioxide Emissions from Tropical Wet Forest Soils: The Role of Leaf Cutter Ant Atta Cepholotes

    Science.gov (United States)

    Harmon, T. C.; Fernandez Bou, A. S.; Dierick, D.; Oberbauer, S. F.; Schwendenmann, L.; Swanson, A. C.; Zelikova, T. J.

    2016-12-01

    This project focuses on the role of leaf cutter ants (LCA) Atta cepholotes in carbon cycling in neotropical wet forests. LCA are abundant in these forests and workers cut and carry vegetation fragments to their nests, where symbiotic fungi break down the plant material and produce the fungal hyphae on which the ants feed. LCA are the dominant herbivores in tropical forest ecosystems, removing 10-50% of vegetation annually. Their nests can achieve large sizes, extending several meters belowground and covering 50 square meters or more of the forest floor. We monitored soil moisture, temperature, and soil CO2 concentrations continuously in nest and control sites at La Selva Biological Station, Costa Rica. Intermittently, we also assessed soil respiration and LCA nest vent fluxes. Observed soil CO2 concentrations varied markedly with soil moisture conditions, ranging from a few thousand to over 60,000 ppm(v). Accordingly, soil CO2 surface efflux varied temporally by an order of magnitude or more (typical range 0.5 to 5 mmol CO2 m-2 s-1) for the same location as a consequence of soil moisture fluctuations. LCA nest vents equivalent CO2 efflux rates (accounting for vent diameter) can be substantially greater than soil surface values, with observed values ranging from about 1 to 50 mmol m-2 s-1 (it is worth noting that correcting for vent diameters yields equivalent CO2 efflux rates greater than 1000 mmol m-2 s-1). Similar to the soil surface efflux, vent efflux varied temporally by factors of 3 or more, suggesting a potential link between the vent productivity and nest activity, moisture content of surrounding soil, and atmospheric conditions (e.g., air temperature, wind). Using a soil model (Hydrus-1D) to account for unsaturated flow, heat transfer, CO2 production and diffusive transport, we captured moisture and temperature dynamics and the order of magnitude of observed CO2 concentration. Modelled surface fluxes also agreed well with observed soil surface CO2 efflux

  7. Upgrading of Drive System in KTC80 Tobacco Cutter%KTC80切丝机驱动系统的改造

    Institute of Scientific and Technical Information of China (English)

    杨晓春

    2011-01-01

    KTC80切丝机采用液压驱动,工作压力高,液压油易泄漏污染烟丝,为此对切丝机驱动系统进行了改造.改造后切丝机取消了液压系统及PIV减速器,采用交流异步伺服电机、交流同步伺服电机分别驱动刀辊、排链;采用S7 - 300C PLC对刀辊转速和排链转速实施控制,烟丝宽度通过触摸屏可任意设定;采用气动控制直角曲柄增压机构压实烟草物料.应用结果表明,改造后KTC80切丝机解决了漏油问题,梗丝宽度误差减少了1.41百分点,碎丝率降低了0.03百分点,整丝率提高了0.98百分点.减少了零配件数量,降低了备件费用,操作维修简便,提高了设备的整机技术水平.%In KTC80 tobacco cutter with hydraulic drive system, the hydraulic oil tends to leak and pollute cut tobacco because of high working pressure. Therefore, the drive system was upgraded as following: adopting AC asynchronous servo motor and AC synchronous servo motor in the place of hydraulic system and PIV reducer to drive knife drum and band respectively; using SIEMENS S7 - 300C PLC to control the speed of knife drum and band, setting the width of cut tobacco at will on a touch screen; adopting pneumatic controlled right-angle crank pressure booster for tobacco compression. The application results showed that oil leakage was avoided, the error of cut stem width and the proportion of short strands reduced by 1.41 and 0.03 percentage points, respectively; while the proportion of long strands increased by 0.98 percentage points. The amount and cost of spare parts decreased, machine operation and maintenance were simpler, and the complete equipment was promoted technically.

  8. Fixed target facility at the SSC

    Energy Technology Data Exchange (ETDEWEB)

    Loken, S.C.; Morfin, J.G.

    1985-01-01

    The question of whether a facility for fixed target physics should be provided at the SSC must be answered before the final technical design of the SSC can be completed, particularly if the eventual form of extraction would influence the magnet design. To this end, an enthusiastic group of experimentalists, theoreticians and accelerator specialists have studied this point. The accelerator physics issues were addressed by a group led by E. Colton whose report is contained in these proceedings. The physics addressable by fixed target was considered by many of the Physics area working groups and in particular by the Structure Function Group. This report is the summary of the working group which considered various SSC fixed target experiments and determined which types of beams and detectors would be required. 13 references, 5 figures.

  9. Fixed drug eruption due to paracetamol

    Directory of Open Access Journals (Sweden)

    Anjali Kushwah

    2013-12-01

    Full Text Available Fixed drug eruption is a common type of drug eruption seen in dermatology OPD’s. Usually it is seen with sulphonamides, salicylates, tetracyclines, oxyphenbutazones, dapsone, barbiturates, phenolphthalein, morphine, codeine, quinine, phenacetin, erythromycin, griseofulvin, mebendazole etc. We hereby report a case of fixed drug eruption due to single dose of oral paracetamol in an otherwise healthy male after one hour of consuming it. A provisional diagnosis of Paracetamol induced fixed drug eruption was made. Paracetamol was stopped and patient advised never to take Paracetamol in future. Patient was managed with prednisolone 10mg /day, cetirizine 10 mg/day, and amoxicillin 500 mg twice a day and mometasone + fusidic acid cream to be applied over the lesions. [Int J Basic Clin Pharmacol 2013; 2(6.000: 833-835

  10. Fixed point theory of parametrized equivariant maps

    CERN Document Server

    Ulrich, Hanno

    1988-01-01

    The first part of this research monograph discusses general properties of G-ENRBs - Euclidean Neighbourhood Retracts over B with action of a compact Lie group G - and their relations with fibrations, continuous submersions, and fibre bundles. It thus addresses equivariant point set topology as well as equivariant homotopy theory. Notable tools are vertical Jaworowski criterion and an equivariant transversality theorem. The second part presents equivariant cohomology theory showing that equivariant fixed point theory is isomorphic to equivariant stable cohomotopy theory. A crucial result is the sum decomposition of the equivariant fixed point index which provides an insight into the structure of the theory's coefficient group. Among the consequences of the sum formula are some Borsuk-Ulam theorems as well as some folklore results on compact Lie-groups. The final section investigates the fixed point index in equivariant K-theory. The book is intended to be a thorough and comprehensive presentation of its subjec...

  11. Fabrication and Characteristics of Thermocouple Temperature Measuring Cutter for Cutting Zone%切削区热电偶测温刀具的制备及其性能测试

    Institute of Scientific and Technical Information of China (English)

    刘志军; 林新贵; 全燕鸣

    2015-01-01

    由于切削测温温感器无法直接接触切削区,故在铂铑丝表面喷涂耐热绝缘层制作耐热热电偶,把表面覆盖耐热绝缘层的热电偶埋入硬质合金粉末,压制、烧结成热电偶测温刀片。通过恒温箱测温实验判定热电偶的测温性能,用性能正常的热电偶测温刀具进行切削测温实验,测温实验结果及切削刀具镜测结果表明,热电偶测温刀具能直接、可靠地进行切削区温度的测量,但是用此工艺制作的刀具切削寿命较短;实验结果还表明直径越大的铂铑丝制作的热电偶测温刀具的成品率越高,但是铂铑丝直径越大,刀具寿命越短;实验进一步揭示切削区内各点的温差较大,但是一次切削切削区温度场处于稳态时切削测温点的温度是稳定的,温度场处于稳态时切削温度的变化能迅速反映刀具的磨损状态的变化。%Cutting temperature measurement sensor could not directly contact the cutting zone,for resolving this problem,a heat-resistant insulation layer was sprayed on the surface of platinum rhodi-um wire so as to form the heat-resistant thermocouple initially,and then,the thermocouple covered by a heat insulation layer was embedded into the cemented carbide powder,and pressed and sintered to form a thermocouple temperature measuring blade.Temperature measuring performance of thermo-couple was judged by the temperature measurement experiments in thermostat,and the normal ther-mocouple temperature measuring cutter was used in the experiments of cutting temperature measure-ment.The experiments show that the thermocouple temperature measuring cutter can take the tem-perature measurement of the cutting zone directly and reliably,but the life of cutter is short.Experi-ments also show that the larger the diameter of platinum rhodium wire,the higher yield of the ther-mocouple temperature measuring cutter,but accordingly,the life of cutter is shorter.Experiments fur

  12. Fix og færdig

    Directory of Open Access Journals (Sweden)

    Jens Pedersen

    2012-12-01

    Full Text Available Fix & Finish “WHO CAN FIX IT?” is an investigation of the needles left behind by drug users in Copenhagen’s Vesterbro district. Based on the praxiological methods developed by Annemarie Mol as well as processes of objectification as described by Daniel Miller, the used needle appears to be a multiple object that is related to opportunities, fear, good intentions and trash. This article is an invitation to study material culture and material practices as a part of semiotic and discursive analyses in order to sharpen a researcher’s analytical focus while remaining grounded in reality.

  13. Duan's fixed point theorem: Proof and generalization

    Directory of Open Access Journals (Sweden)

    Arkowitz Martin

    2006-01-01

    Full Text Available Let be an H-space of the homotopy type of a connected, finite CW-complex, any map and the th power map. Duan proved that has a fixed point if . We give a new, short and elementary proof of this. We then use rational homotopy to generalize to spaces whose rational cohomology is the tensor product of an exterior algebra on odd dimensional generators with the tensor product of truncated polynomial algebras on even dimensional generators. The role of the power map is played by a -structure as defined by Hemmi-Morisugi-Ooshima. The conclusion is that and each has a fixed point.

  14. Fixed export cost heterogeneity, trade and welfare

    DEFF Research Database (Denmark)

    Jørgensen, Jan Guldager; Schröder, Philipp J.H.

    2008-01-01

    -country intra-industry trade model where firms are of two different marginal costs types and where fixed export costs are heterogeneous across firms. This model traces many of the stylized facts of international trade. However, we find that with heterogeneous fixed export costs there exists a positive bilateral......Recent literature on the workhorse model of intra-industry trade has explored heterogeneous cost structures at the firm level. These approaches have proven to add realism and predictive power. This paper presents a new and simple heterogeneous-firms specification. We develop a symmetric two...

  15. Fixed and variable cost of automobiles

    DEFF Research Database (Denmark)

    Mulalic, Ismir; Rouwendal, Jan

    Recent empirical analyses have found strong reactions of car prices to changes in fuel costs. We develop a model of car quality choice to further investigate this relationship. We show that in the empirically relevant case quality characteristics increase fixed as well as variable costs, and our...... model focuses on that situation. Quality aspects must then be an argument of the utility function and we introduce them in a general way. In equilibrium the marginal willingness to pay for these aspects must be equal to their margi nal impact on fixed as well as variable costs. We estimate the marginal...

  16. General Common Fixed Point Theorems and Applications

    Directory of Open Access Journals (Sweden)

    Shyam Lal Singh

    2012-01-01

    Full Text Available The main result is a common fixed point theorem for a pair of multivalued maps on a complete metric space extending a recent result of Đorić and Lazović (2011 for a multivalued map on a metric space satisfying Ćirić-Suzuki-type-generalized contraction. Further, as a special case, we obtain a generalization of an important common fixed point theorem of Ćirić (1974. Existence of a common solution for a class of functional equations arising in dynamic programming is also discussed.

  17. Fixed Wordsize Implementation of Lifting Schemes

    Science.gov (United States)

    Karp, Tanja

    2006-12-01

    We present a reversible nonlinear discrete wavelet transform with predefined fixed wordsize based on lifting schemes. Restricting the dynamic range of the wavelet domain coefficients due to a fixed wordsize may result in overflow. We show how this overflow has to be handled in order to maintain reversibility of the transform. We also perform an analysis on how large a wordsize of the wavelet coefficients is needed to perform optimal lossless and lossy compressions of images. The scheme is advantageous to well-known integer-to-integer transforms since the wordsize of adders and multipliers can be predefined and does not increase steadily. This also results in significant gains in hardware implementations.

  18. Carbon-Fixing Reactions of Photosynthesis.

    Science.gov (United States)

    2016-07-01

    Summaryplantcell;28/7/tpc.116.tt0716/FIG1F1fig1Photosynthesis in plants converts the energy of sunlight into chemical energy. Although photosynthesis involves many proteins and catalytic processes, it often is described as two sets of reactions, the light-dependent reactions and the carbon-fixing reactions. This lesson introduces the core biochemistry of the carbon-fixing reactions of photosynthesis, as well as its variations, C4 and CAM. Finally, it addresses how and why plants are affected by rising atmospheric CO2 levels, and research efforts to increase photosynthetic efficiency in current and future conditions. © 2016 American Society of Plant Biologists. All rights reserved.

  19. Recurrent fixed drug eruption caused by citiolone.

    Science.gov (United States)

    de Barrio, M; Tornero, P; Prieto, A; Sainza, T; Zubeldia, J M; Herrero, T

    1997-01-01

    Citiolone (N-acetylhomocysteinethiolactone) is a thiolic-derived medication frequently used in Spain and in other countries as a mucolytic agent for the treatment of certain hepatic disorders. Mucolytic drugs have rarely been implicated in the fixed drug eruption etiology. We report on a patient who presented several episodes of fixed exanthema related to citiolone intake. The patch test with citiolone (10% in dimethyl sulfoxide) was negative. The diagnosis was confirmed by a positive controlled oral challenge test. Other mucolytic thiolic-derivatives (N-acetylcysteine) were tolerated by the patient, thus crossreactivity between these drugs seems to be unlikely.

  20. Stress tolerant crops from nitrogen fixing trees

    Energy Technology Data Exchange (ETDEWEB)

    Becker, R.; Saunders, R.M.

    1983-01-01

    Notes are given on the nutritional quality and uses of: pods of Geoffroea decorticans, a species tolerant of saline and limed soils and saline water; seeds of Olneya tesota which nodulates readily and fixes nitrogen and photosynthesizes at low water potential; and pods of Prosopis chilensis and P. tamarugo which tolerate long periods without rain. 3 references.

  1. Untangling Fixed Effects and Constant Regressors

    NARCIS (Netherlands)

    Klaassen, F.; Teulings, R.

    2015-01-01

    Fixed effects (FE) in panel data models overlap each other and prohibit the identification of the impact of "constant" regressors. Think of regressors that are constant across countries in a country-time panel with time FE. The traditional approach is to drop some FE and constant regressors by

  2. Tunnel Diode Discriminator with Fixed Dead Time

    DEFF Research Database (Denmark)

    Diamond, J. M.

    1965-01-01

    A solid state discriminator for the range 0.4 to 10 V is described. Tunnel diodes are used for the discriminator element and in a special fixed dead time circuit. An analysis of temperature stability is presented. The regulated power supplies are described, including a special negative resistance...

  3. Fixing the Shadows While Moving the Gnomon

    Science.gov (United States)

    Gangui, Alejandro

    2015-01-01

    It is a common practice to fix a vertical gnomon and study the moving shadow cast by it. This shows our local solar time and gives us a hint regarding the season in which we perform the observation. The moving shadow can also tell us our latitude with high precision. In this paper we propose to exchange the roles and while keeping the shadows…

  4. Simplicial fixed point algorithms and applications

    NARCIS (Netherlands)

    Yang, Z.F.

    1996-01-01

    Fixed point theory is an important branch of modern mathematics and has always been a major theoretical tool in fields such as differential equations, topology, function analysis, optimal control, economics, and game theory. Its applicability has been increased enormously by the development of

  5. Empirical Studies on Sovereign Fixed Income Markets

    NARCIS (Netherlands)

    J.G. Duyvesteyn (Johan)

    2015-01-01

    markdownabstractAbstract This dissertation presents evidence of five studies showing that sovereign fixed income markets are not always price efficient. The emerging local currency debt market has grown to a large size of more than 1.5 trill ion US Dollars at the end of 2012. The factors

  6. Common Fixed Points for Weakly Compatible Maps

    Indian Academy of Sciences (India)

    Renu Chugh; Sanjay Kumar

    2001-05-01

    The purpose of this paper is to prove a common fixed point theorem, from the class of compatible continuous maps to a larger class of maps having weakly compatible maps without appeal to continuity, which generalized the results of Jungck [3], Fisher [1], Kang and Kim [8], Jachymski [2], and Rhoades [9].

  7. A New Fixed Point Theorem and Applications

    Directory of Open Access Journals (Sweden)

    Min Fang

    2013-01-01

    Full Text Available A new fixed point theorem is established under the setting of a generalized finitely continuous topological space (GFC-space without the convexity structure. As applications, a weak KKM theorem and a minimax inequalities of Ky Fan type are also obtained under suitable conditions. Our results are different from known results in the literature.

  8. A Dynamical Approach to Gauge Fixing

    CERN Document Server

    Loran, F

    2002-01-01

    We study gauge fixing in the generalized Gupta-Bleuler quantization. In this method physical states are defined to be simultaneous null eigenstates of a set of quantum invariants. We apply the method to a solvable model proposed by Friedberg, Lee, Pang and Ren and show that no Gribov-type copies appears by construction.

  9. Some Generalizations of Jungck's Fixed Point Theorem

    Directory of Open Access Journals (Sweden)

    J. R. Morales

    2012-01-01

    Full Text Available We are going to generalize the Jungck's fixed point theorem for commuting mappings by mean of the concepts of altering distance functions and compatible pair of mappings, as well as, by using contractive inequalities of integral type and contractive inequalities depending on another function.

  10. Fixed Point Theorems for Asymptotically Contractive Multimappings

    Directory of Open Access Journals (Sweden)

    M. Djedidi

    2012-01-01

    Full Text Available We present fixed point theorems for a nonexpansive set-valued mapping from a closed convex subset of a reflexive Banach space into itself under some asymptotic contraction assumptions. Some existence results of coincidence points and eigenvalues for multimappings are given.

  11. Generalized Common Fixed Point Results with Applications

    Directory of Open Access Journals (Sweden)

    Marwan Amin Kutbi

    2014-01-01

    Full Text Available We obtained some generalized common fixed point results in the context of complex valued metric spaces. Moreover, we proved an existence theorem for the common solution for two Urysohn integral equations. Examples are presented to support our results.

  12. Force dynamics in fixed-ratio schedules.

    Science.gov (United States)

    Pinkston, Jonathan W; McBee, Lindsey N

    2014-03-01

    Fixed-ratio schedules are widely used in behavioral research. Although fixed-ratio schedules often conjure up relationships to work and effort, little is known about effort-related measures in these schedules. Early research had shown that force and effort of operant behavior vary systematically during the execution of ratio schedules, and the goal of the present study was to revisit early research on force dynamics in fixed-ratio schedules. Four rats earned sucrose by pressing an isometric force transducer. Presses produced sucrose after ten or twenty responses. In general, the force of responses increased then decreased systematically across the ratio. The possibility that decreases in force during ratio execution was due to a trade-off with the differential reinforcement of short inter-response times (IRT) was investigated in an additional condition where sucrose was made available according to a tandem fixed-ratio 19 inter-response (IRT)> t schedule. The tandem IRT requirement did not eliminate decreasing trends in force across the ratio; unexpectedly, the tandem requirement did eliminate increases in force early in the ratio, which may reflect sequence-level organization operating in the control of force dynamics.

  13. Efficient Fixed-Offset GPR Scattering Analysis

    DEFF Research Database (Denmark)

    Meincke, Peter; Chen, Xianyao

    2004-01-01

    in the scattering calculation the correct radiation patterns of the ground penetrating radar antennas by using their plane-wave transmitting and receiving spectra. Finally, we derive an efficient FFT-based method to analyze a fixed-offset configuration in which the location of the transmitting antenna is different...

  14. Uniqueness of entire functions and fixed points

    OpenAIRE

    Chang, Jianming; Fang, Mingliang

    2002-01-01

    Let $f$ be a nonconstant entire function. %If $f(z)=z$ $\\Longleftrightarrow $ $f'(z)=z$, and %$f'(z)=z$ $\\Longrightarrow $ $f''(z)=z$, then $f\\equiv f'$. In particular, If $f$, $f'$ and $f''$ have the same fixed points, then $f\\equiv f'.$

  15. Untangling Fixed Effects and Constant Regressors

    NARCIS (Netherlands)

    Klaassen, F.; Teulings, R.

    2015-01-01

    Fixed effects (FE) in panel data models overlap each other and prohibit the identification of the impact of "constant" regressors. Think of regressors that are constant across countries in a country-time panel with time FE. The traditional approach is to drop some FE and constant regressors by norma

  16. 29 CFR 1910.27 - Fixed ladders.

    Science.gov (United States)

    2010-07-01

    .... (v) The rungs of an individual-rung ladder shall be so designed that the foot cannot slide off the... OCCUPATIONAL SAFETY AND HEALTH STANDARDS Walking-Working Surfaces § 1910.27 Fixed ladders. (a) Design requirements—(1) Design considerations. All ladders, appurtenances, and fastenings shall be designed to...

  17. Simplicial fixed point algorithms and applications

    NARCIS (Netherlands)

    Yang, Z.F.

    1996-01-01

    Fixed point theory is an important branch of modern mathematics and has always been a major theoretical tool in fields such as differential equations, topology, function analysis, optimal control, economics, and game theory. Its applicability has been increased enormously by the development of simpl

  18. Empirical Studies on Sovereign Fixed Income Markets

    NARCIS (Netherlands)

    J.G. Duyvesteyn (Johan)

    2015-01-01

    markdownabstractAbstract This dissertation presents evidence of five studies showing that sovereign fixed income markets are not always price efficient. The emerging local currency debt market has grown to a large size of more than 1.5 trill ion US Dollars at the end of 2012. The factors that

  19. Uniqueness of entire functions and fixed points

    OpenAIRE

    Chang, Jianming; Fang, Mingliang

    2002-01-01

    Let $f$ be a nonconstant entire function. %If $f(z)=z$ $\\Longleftrightarrow $ $f'(z)=z$, and %$f'(z)=z$ $\\Longrightarrow $ $f''(z)=z$, then $f\\equiv f'$. In particular, If $f$, $f'$ and $f''$ have the same fixed points, then $f\\equiv f'.$

  20. Fixed points and self-reference

    Directory of Open Access Journals (Sweden)

    Raymond M. Smullyan

    1984-01-01

    Full Text Available It is shown how Gödel's famous diagonal argument and a generalization of the recursion theorem are derivable from a common construation. The abstract fixed point theorem of this article is independent of both metamathematics and recursion theory and is perfectly comprehensible to the non-specialist.

  1. Interactive Inconsistency Fixing in Feature Modeling

    Institute of Scientific and Technical Information of China (English)

    王波; 熊英飞; 胡振江; 赵海燕; 张伟; 梅宏

    2014-01-01

    Feature models have been widely adopted to reuse the requirements of a set of similar products in a domain. In feature models’ construction, one basic task is to ensure the consistency of feature models, which often involves detecting and fixing of inconsistencies in feature models. While many approaches have been proposed, most of them focus on detecting inconsistencies rather than fixing inconsistencies. In this paper, we propose a novel dynamic-priority based approach to interactively fixing inconsistencies in feature models, and report an implementation of a system that not only automatically recommends a solution to fixing inconsistencies but also supports domain analysts to gradually reach the desirable solution by dynamically adjusting priorities of constraints. The key technical contribution is, as far as we are aware, the first application of the constraint hierarchy theory to feature modeling, where the degree of domain analysts’ confidence on constraints is expressed by using priority and inconsistencies are resolved by deleting one or more lower-priority constraints. Two case studies demonstrate the usability and scalability (effciency) of our new approach.

  2. 46 CFR 184.410 - Electronic position fixing devices.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Electronic position fixing devices. 184.410 Section 184... Electronic position fixing devices. A vessel on an oceans route must be equipped with an electronic position fixing device, capable of providing accurate fixes for the area in which the vessel operates, to...

  3. 46 CFR 28.260 - Electronic position fixing devices.

    Science.gov (United States)

    2010-10-01

    ... Trade § 28.260 Electronic position fixing devices. Each vessel 79 feet (24 meters) or more in length must be equipped with an electronic position fixing device capable of providing accurate fixes for the... 46 Shipping 1 2010-10-01 2010-10-01 false Electronic position fixing devices. 28.260 Section...

  4. 46 CFR 118.410 - Fixed gas fire extinguishing systems.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Fixed gas fire extinguishing systems. 118.410 Section... PROTECTION EQUIPMENT Fixed Fire Extinguishing and Detecting Systems § 118.410 Fixed gas fire extinguishing systems. (a) General. (1) A fixed gas fire extinguishing system aboard a vessel must be approved by...

  5. 46 CFR 181.410 - Fixed gas fire extinguishing systems.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Fixed gas fire extinguishing systems. 181.410 Section... Fixed gas fire extinguishing systems. (a) General. (1) A fixed gas fire extinguishing system aboard a... approved for the system by the Commandant. (4) A fixed gas fire extinguishing system may protect more...

  6. Fixed-phase vs fixed-node quantum Monte Carlo with local and nonlocal interactions

    Science.gov (United States)

    Mitas, Lubos; Melton, Cody

    We study several systems that can be formulated in the fixed-phase and/or fixed-node framework in quantum Monte Carlo calculations. In particular, we try to understand the differences between the biases caused by these approximations that result from using complex vs real trial wave functions. One system is a model that enables us to construct systematically the same type of nodal errors in both real and complex formalism. The errors are comparably similar whenever trial functions are correspondingly accurate. Another aspect of the fixed-phase vs fixed-node approximations is studied for systems with nonlocal operators such as with pseudopotentials and/or spin-orbit effects. We specify how to obtain variational formulation for complex wave functions and nonlocal operators in a manner analogous to the fixed-node calculations with T-moves algorithm. In particular, we show that the fixed-phase/fixed-node is the primary condition for proving that the upper bound property holds.

  7. ANALYTICAL SOLUTION FOR FIXED-FIXED ANISOTROPIC BEAM SUBJECTED TO UNIFORM LOAD

    Institute of Scientific and Technical Information of China (English)

    DING Hao-jiang; HUANG De-jin; WANG Hui-ming

    2006-01-01

    The analytical solutions of the stresses and displacements were obtained for fixed-fixed anisotropic beams subjected to uniform load. A stress function involving unknown coefficients was constructed, and the general expressions of stress and displacement were obtained by means of Airy stress function method. Two types of the description for the fixed end boundary condition were considered. The introduced unknown coefficients in stress function were determined by using the boundary conditions. The analytical solutions for stresses and displacements were finally obtained. Numerical tests show that the analytical solutions agree with the FEM results. The analytical solution supplies a classical example for the elasticity theory.

  8. 2010 Joint United States-Canadian Program to explore the limits of the Extended Continental Shelf aboard U.S. Coast Guard Cutter Healy--Cruise HLY1002

    Science.gov (United States)

    Edwards, Brian D.; Childs, Jonathan R.; Triezenberg, Peter J.; Danforth, William W.; Gibbons, Helen

    2013-01-01

    In August and September 2010, the U.S. Geological Survey, in cooperation with Natural Resources Canada, Geological Survey of Canada, conducted bathymetric and geophysical surveys in the Beaufort Sea and eastern Arctic Ocean aboard the U.S. Coast Guard Cutter Healy. The principal objective of this mission to the high Arctic was to acquire data in support of a delineation of the outer limits of the U.S. and Canadian Extended Continental Shelf in the Arctic Ocean, in accordance with the provisions of Article 76 of the United Nations Convention on the Law of the Sea. The Healy was accompanied by the Canadian Coast Guard icebreaker Louis S. St-Laurent. The scientific parties on board the two vessels consisted principally of staff from the U.S. Geological Survey (Healy), and the Geological Survey of Canada and the Canadian Hydrographic Service (Louis). The crew also included marine-mammal observers, Native-community observers, ice observers, and biologists conducting research of opportunity in the Arctic Ocean. Despite interruptions necessitated by three medical emergencies, the joint survey proved largely successful. The Healy collected 7,201 trackline-kilometers of swath (multibeam) bathymetry (47,663 square kilometers) and CHIRP subbottom data, with accompanying marine gravity measurements, and expendable bathythermograph data. The Louis acquired 3,673 trackline-kilometers of multichannel seismic (airgun) deep-penetration reflection data along 25 continuous profiles, as well as 34 sonobuoy refraction stations and 9,500 trackline-kilometers of single-beam bathymetry. The coordinated efforts of the two vessels resulted in seismic-reflection-profile data that were of much higher quality and continuity than if the data had been acquired with a single vessel alone. The equipment-failure rate of the seismic equipment aboard the Louis was greatly reduced when the Healy led as the ice breaker. When ice conditions proved too severe to deploy the seismic system, the Louis led

  9. Duan's fixed point theorem: proof and generalization

    Directory of Open Access Journals (Sweden)

    2006-01-01

    Full Text Available Let X be an H-space of the homotopy type of a connected, finite CW-complex, f:X→X any map and p k :X→X the k th power map. Duan proved that p k f :X→X has a fixed point if k≥2 . We give a new, short and elementary proof of this. We then use rational homotopy to generalize to spaces X whose rational cohomology is the tensor product of an exterior algebra on odd dimensional generators with the tensor product of truncated polynomial algebras on even dimensional generators. The role of the power map is played by a θ -structure μ θ :X→X as defined by Hemmi-Morisugi-Ooshima. The conclusion is that μ θ f and f μ θ each has a fixed point.

  10. Fixing the shadows while moving the gnomon

    CERN Document Server

    Gangui, Alejandro

    2016-01-01

    It is a common practice to fix a vertical gnomon and study the moving shadow cast by it. This shows our local solar time and gives us a hint regarding the season in which we perform the observation. The moving shadow can also tell us our latitude with high precision. In this paper we propose to exchange the roles and while keeping the shadows fixed on the ground we will move the gnomon. This lets us understand in a simple way the relevance of the tropical lines of latitude and the behavior of shadows in different locations. We then put these ideas into practice using sticks and threads during a solstice on two sites located on opposite sides of the Tropic of Capricorn.

  11. Fixed Wordsize Implementation of Lifting Schemes

    Directory of Open Access Journals (Sweden)

    Tanja Karp

    2007-01-01

    Full Text Available We present a reversible nonlinear discrete wavelet transform with predefined fixed wordsize based on lifting schemes. Restricting the dynamic range of the wavelet domain coefficients due to a fixed wordsize may result in overflow. We show how this overflow has to be handled in order to maintain reversibility of the transform. We also perform an analysis on how large a wordsize of the wavelet coefficients is needed to perform optimal lossless and lossy compressions of images. The scheme is advantageous to well-known integer-to-integer transforms since the wordsize of adders and multipliers can be predefined and does not increase steadily. This also results in significant gains in hardware implementations.

  12. Selective fixed drug eruption to amoxycillin.

    Science.gov (United States)

    Arias, J; Férnandez-Rivas, M; Panadero, P

    1995-07-01

    A selective fixed drug eruption to amoxycillin but not other betalactam drugs is reported. Penicillins are the drugs most frequently implicated in immunological adverse reactions. The most important of these are allergic reactions where an IgE-mediated mechanism is well established. Other immunological mechanisms have been described in reactions, such as haemolytic anaemia, serum sickness, drug-induced nephritis, drug fever and contact dermatitis. Fixed drug eruption (FDE) is a type of drug-induced dermatosis, the immunopathogenesis of which remains unknown. FDE is an uncommon reaction to penicillin derivatives, and very few cases have been reported. We present a case of a selective FDE to amoxycillin (AX), with no reaction to other betalactam drugs. Although one similar case has been reported, the reactivity to other penicillin derivatives was not assessed.

  13. An Extension of Gregus Fixed Point Theorem

    Directory of Open Access Journals (Sweden)

    J. O. Olaleru

    2007-03-01

    Full Text Available Let C be a closed convex subset of a complete metrizable topological vector space (X,d and T:C→C a mapping that satisfies d(Tx,Ty≤ad(x,y+bd(x,Tx+cd(y,Ty+ed(y,Tx+fd(x,Ty for all x,y∈C, where 0fixed point. The above theorem, which is a generalization and an extension of the results of several authors, is proved in this paper. In addition, we use the Mann iteration to approximate the fixed point of T.

  14. Time Stamps for Fixed-Point Approximation

    DEFF Research Database (Denmark)

    Damian, Daniela

    2001-01-01

    Time stamps were introduced in Shivers's PhD thesis for approximating the result of a control-flow analysis. We show them to be suitable for computing program analyses where the space of results (e.g., control-flow graphs) is large. We formalize time-stamping as a top-down, fixed-point approximat......Time stamps were introduced in Shivers's PhD thesis for approximating the result of a control-flow analysis. We show them to be suitable for computing program analyses where the space of results (e.g., control-flow graphs) is large. We formalize time-stamping as a top-down, fixed......-point approximation algorithm which maintains a single copy of intermediate results. We then prove the correctness of this algorithm....

  15. Impulsive differential inclusions a fixed point approach

    CERN Document Server

    Ouahab, Abdelghani; Henderson, Johnny

    2013-01-01

    Impulsive differential equations have been developed in modeling impulsive problems in physics, population dynamics, ecology, biotechnology, industrial robotics, pharmacokinetics, optimal control, etc. The questions of existence and stability of solutions for different classes of initial values problems for impulsive differential equations and inclusions with fixed and variable moments are considered in detail. Attention is also given to boundary value problems and relative questions concerning differential equations. This monograph addresses a variety of side issues that arise from its simple

  16. The nonlinear fixed gravimetric boundary value problem

    Institute of Scientific and Technical Information of China (English)

    于锦海; 朱灼文

    1995-01-01

    The properly-posedness of the nonlinear fixed gravimetric boundary value problem is shown with the help of nonlinear functional analysis and a new iterative method to solve the problem is also given, where each step of the iterative program is reduced to solving one and the same kind of oblique derivative boundary value problem with the same type. Furthermore, the convergence of the iterative program is proved with Schauder estimate of elliptic differential equation.

  17. Fixed-Field Alternating-Gradient Accelerators

    CERN Document Server

    Sheehy, S L

    2016-01-01

    These notes provide an overview of Fixed-Field Alternating-Gradient (FFAG) accelerators for medical applications. We begin with a review of the basic principles of this type of accelerator, including the scaling and non-scaling types, highlighting beam dynamics issues that are of relevance to hadron ac- celerators. The potential of FFAG accelerators in the field of hadron therapy is discussed in detail, including an overview of existing medical FFAG designs. The options for FFAG treatment gantries are also considered.

  18. Morphing fixed wing MAV modeling using VAM

    OpenAIRE

    2012-01-01

    The design and implementation of a morphing Micro Air Vehicle (MAV) wing using a smart composite is attempted in this research work. Control surfaces actuated by traditional servos are difficult to instrument and fabricate on thin composite-wings of MAVs. Piezoelectric Fiber Reinforced Composites (PFRCs) are the chosen smart structural materials in the current work for incorporation onto fixed-wing MAVs to simultaneously perform the dual functions of structural load-bearing and actuatio...

  19. Optimal investment with fixed refinancing costs

    OpenAIRE

    Cummins, Jason G; Ingmar Nyman

    2001-01-01

    Case studies show that corporate managers seek financial independence to avoid interference by outside financiers. We incorporate this financial xenophobia as a fixed cost in a simple dynamic model of financing and investment. To avoid refinancing in the future, the firm alters its behavior depending on the extent of its financial xenophobia and the realization of a revenue shock. With a sufficiently adverse shock, the firm holds no liquidity. Otherwise, the firm precautionarily saves and hol...

  20. Low Actuation Voltage RF MEMS Switch Using Varying Section Composite Fixed-Fixed Beam

    Directory of Open Access Journals (Sweden)

    M. Manivannan

    2014-01-01

    Full Text Available The present authors have earlier reported the employment of varying section fixed-fixed beam for achieving lower pull-in voltage with marginal fall in restoring force. Reducing Young’s modulus also reduces the pull-in voltage but with lesser degree of reduction in restoring force. Composite beams are ideal alternatives to achieve decreased Young’s modulus. Hence new varying section composite fixed-fixed beam type RF MEMS switch has been proposed. The main advantage of this RF MEMS switch is that lower pull-in voltages can be achieved with marginal fall in stiction immunity. Spring constant of the proposed switch has been obtained using simulation studies and it has been shown that the spring constant and therefore the pull-in voltage (Vpi can be considerably reduced with the proposed switch. Simulation studies conducted on the proposed switch clearly demonstrate that the pull-in voltage can be reduced by 31.17% when compared to the varying section monolayer polysilicon fixed-fixed beam. Further this approach enables the designer to have more freedom to design lower pull-in voltage switches with improved stiction immunity.

  1. Fixed behaviours and migration in parasitic flatworms.

    Science.gov (United States)

    Sukhdeo, M V K; Sukhdeo, S C

    2002-03-01

    This paper considers how fixed behaviours may play a role in post-larval migrations of Entobdella soleae. A general argument is that a shift away from the paradigm of orientation is required to elucidate the mechanisms that parasites use to navigate on the surface of their hosts. Some migrations may rely on fixed behaviours (genetically programmed stereotyped behaviours) that often evolve under predictable environmental conditions with reliable signals. In turbulent and stochastic free-living environments, homeostatic hosts present very predictable topological substrates and physico-chemical characteristics to their parasites. Over the course of evolution on these predictable host substrates, adaptive behaviours in the parasites can become fixed. Examples of endoparasite migration behaviour, particularly that of the common liver fluke, Fasciola hepatica, will be used to develop an approach based on the perceptual worlds of migrating parasites. An important conclusion is that multi-disciplinary approaches, firmly rooted in an understanding of each parasite's natural history, are requisite to successful interpretation of migration behaviours on the host.

  2. Fixed point theory in distance spaces

    CERN Document Server

    Kirk, William

    2014-01-01

    This is a monograph on fixed point theory, covering the purely metric aspects of the theory–particularly results that do not depend on any algebraic structure of the underlying space. Traditionally, a large body of metric fixed point theory has been couched in a functional analytic framework. This aspect of the theory has been written about extensively. There are four classical fixed point theorems against which metric extensions are usually checked. These are, respectively, the Banach contraction mapping principal, Nadler’s well known set-valued extension of that theorem, the extension of Banach’s theorem to nonexpansive mappings, and Caristi’s theorem. These comparisons form a significant component of this book. This book is divided into three parts. Part I contains some aspects of the purely metric theory, especially Caristi’s theorem and a few of its many extensions. There is also a discussion of nonexpansive mappings, viewed in the context of logical foundations. Part I also contains certain re...

  3. Equipment selection heuristics for microwave fixed links

    Science.gov (United States)

    Flood, I. D.; Allen, S. M.

    2014-08-01

    Microwave fixed links use highly standardized radio equipment and, in the radio equipment standard referenced in this paper, there is a choice between exactly two radio systems when the assigner wishes to resolve a specific data rate exactly: one using a relatively lower-order modulation scheme and one a relatively higher-order scheme. Although the higher-order equipment requires less bandwidth for an isolated link, these systems radiate at higher powers and require larger protection ratios in the radio interference environment which lead to well-established trade-offs between modulation, bandwidth, equivalent isotropic radiated power, and frequency assignment criteria. Our earlier research showed that by extending the Frequency Assignment Problem to include equipment selection and using lower-order modulation equipment on selected links, we can actually reduce the overall span of frequencies required for a network frequency assignment. This work focused on the development of integer programming formulations and analyzed the exact solutions obtained. Exact solutions are impractical for real world problems; hence, here we focus on the development of heuristics for equipment selection. We can model the fixed link network as a complete graph where the vertices represent fixed link frequency assignment requests and the edges represent interference between pairs of vertices. Using a graph theoretic analysis of the interference problem, we propose heuristic techniques and discuss the relative success of our approach in this article.

  4. 木工成型铣刀CAD系统的可视化修改技术%Vision modification function in computer aided design system for woodworking milling cutter

    Institute of Scientific and Technical Information of China (English)

    潘晓文; 詹仕华

    2012-01-01

    This paper issues visual modification technique for woodworking milling cutter CAD system. Design parameters and modeling parameters were embedded in dimension entities by Xdata of AutoCAD, and a VBA program could read (or write) the data embedded in entity which having been picked by user, and then regenerate model, finally the vision modification function was a-chieved.%应用AutoCAD实体扩展数据将设计和造型参数存储于尺寸线中,利用VBA程序读写用户选择的标注实体中的扩展数据,重新生成模型,实现了木工成型铣刀可视化修改.

  5. 轧辊磨床未知包角液体动静压轴承油膜温升计算方法研究%Calculation Method Study of the Oil Film Temperature Rise on Liquid Hybrid Bearing under the Circumstance of Unknown Wrap Angle of Roll Grinder

    Institute of Scientific and Technical Information of China (English)

    蔡家斌; 周元康; 张国萍; 秦川

    2016-01-01

    MK84250 high speed roll grinder spindle uses liquid hybrid bearing, which is to determine the machining quality and efficiency of key components. The temperature rise is a key factor affecting the normal work of the bearing. But due to the solution do-main of its wrap angle of oil film and oil film pressure is unknown and there is no ready-made data, through numerical calculation meth-od, the bearing capacity coefficient-eccentricity function curve of unknown angle was fitted, the bearing structure was analyzed, the flow rate was solved at linear velocity of 45 m/s and the 60 m/s, and the temperature rise was calculated. The calculating results agree with the actual situation.%MK84250高速轧辊磨床主轴所用液体动静压轴承是决定加工质量和效率的关键部件,其温升是影响轴承的正常工作的关键因素.但由于其油膜包角及油膜压力的求解域未知,无现成资料可查,通过数值计算方法拟合了未知包角的承载量系数-偏心率函数曲线,分析了轴承结构并求解了线速度为45 m/s和60 m/s时的流量,并对温升进行了计算.计算结果与实际情况一致.

  6. The Application of Power-Saving and Environment-Protection Measures on the Cutter Suction Dredger%节能环保措施在3500m3/h绞吸式挖泥船上的应用

    Institute of Scientific and Technical Information of China (English)

    宋增有

    2012-01-01

    疏浚船舶是疏浚工作的必备船机设施,它的选型的好坏将直接影响到疏浚工作的效率与成败。阐述了中国船舶及海洋工程设计研究院为连云港港设计的3500m3/h绞吸式挖泥船的节能环保设计思路。重点介绍采用负载转移或功率管理分配等节能措施、采用变频电机取代液压泵站来驱动水下泵及水下绞刀的环保措施等。旨在投资额较为固定的要求下,选型、建造出一艘既技术先进,又节能环保,而且还要安全可靠、平稳高效的绞吸式挖泥船舶。%The dredge boat is an important facility of dredge engineering, the choice of which will influence directly the efficiency and success of dredge. This paper introduces the design idear of power–saving and environment-protection of the 3 500m3/h cutter suction dredger designed by China Ship and Ocean Engineering Design and Research Institute for the Lianyungang port. Emphatically it introduces the power-saving measure of load transferring rate managing and distribution, the environment-protection measure of taking the frequency conversion motor instead of the hydraulic pump station to drive the underwater winch knife. Its aim is to make up a cutter suction dredger of having multi advantages of with advanced technology, power-saving and environment-protection, safety, reliability, stability and efficiency.

  7. 基于机器视觉的种薯自动切块机设计%Design of Automatic Cutter for Potato Used as Seeds Based on Machine Vision

    Institute of Scientific and Technical Information of China (English)

    邢作常; 田素博; 刘思瑶; 白雪卫; 张祖立

    2016-01-01

    现阶段中国市场没有成熟的种薯切块机,薯农主要依靠手工切块。其主要原因是种薯切削需要控制切削位置以保留薯芽的顶端优势,普通机器不能识别薯芽,并控制切刀切削方位。为此,使用数字图像处理技术,实现了薯芽及其位姿的实时识别,开发了相应的控制系统,设计了基于机器视觉的薯种自动切块机。试验表明:薯芽识别正确率达100%,位姿识别正确率达98.5%,耗时107.431ms,满足使用要求。%There is not mature cutter for potato used as seeds in Chinese market at the present .Potato farmers rely mainly on manual cutting .The main reason is that potato cutting used as a seed need to control the cutting position to keep pota-to bud advantage , ordinary machine cannot identify potato bud , and controls the cutter cutting position .Using image pro-cessing technology , the potato bud and its posture real-time identification is realized , the corresponding control system is developed , and the automatic cutting machine is designed based on machine vision .Tests show that potato bud recogni-tion accuracy reaches 100%, posture recognition accuracy reaches 98 .5%, takes 107 .431 ms .it meets the require-ment.

  8. Nitrogen Fixing Legumes in the Plant Communities

    Directory of Open Access Journals (Sweden)

    M. A.A. Al-Fredan

    2011-01-01

    Full Text Available Problems statement: Numerous authors have used energetic to explain the ecological success of N-fixing plants. Legume biodiversity assessment, species dynamics, nitrogen fixation monitoring and environment impact assessment of these ecological events in Al-Hassa Oasis, Saudi Arabia are rare and need to be continuous and more frequent. Approach: Thus the objectives of this study were to analyze legume abundance within and outside Al-Hassa Oasis and relate it to the distribution of the different genera. Results: Thirty two legume plant species from 20 genera have been recorded within and outside the Oasis. The largest genera were Cassia (4 species, Indigofera (4 and Acacia (3. Annual herbs were the dominant growth form (34% of species recorded, followed by shrubs (28%, perennial herbs (19% and trees (19%. Eighteen alien plant species were recorded (maybe an underestimated number. The nitrogen fixation of the legume plant species in Al-Hassa Oasis was estimated/analyzing the fixing potentiality of these species and nonfixing reference species (Panicum turgidum using the 15N natural abundance method. Species with great nitrogen fixing capacity in Al-Hassa include: Medicago sativa, Vicia faba, Vicia sativa, Melitotus indicus, Dolicus lablab, Melitotus alba and Cliforia ternate. The mean biological fixation contribution of most of the recorded legume plants were high, varying from 3.9% (Indigofera argentea to 64.6% (Medicago sativa. Conclusion: Al-Hassa Oasis is richer than expected based on its location within the desert zone. This study confirms the importance of the Oasis for national flora conservation in the Kingdom. results showed a good potential for use of the 15N natural abundance methodology for evaluating the nitrogen fixation ability of the legume plants under field conditions as well as for the estimation of %Ndfa.

  9. Unconventional pontics in fixed partial dentures

    Directory of Open Access Journals (Sweden)

    Mansi Manish Oswal

    2016-01-01

    Full Text Available Clinical success of fixed prosthodontics is dependent in part upon the type of pontic design. The selection of pontic design plays an important role in the outcome of the treatment. At present, there are many different pontic designs and materials present in the market. For some patients, one pontic may have an advantage over another and the choice is a matter of preference with the operator. It is recognized that clinical circumstances will require infinite variations. Hence, the present study briefs about the unconventional pontic designs which can be used on regular basis for better clinical results.

  10. Lattice Chiral Fermions Through Gauge Fixing

    CERN Document Server

    Bock, W; Shamir, Y; Bock, Wolfgang; Golterman, Maarten; Shamir, Yigal

    1998-01-01

    We study a concrete lattice regularization of a U(1) chiral gauge theory. We use Wilson fermions, and include a Lorentz gauge-fixing term and a gauge-boson mass counterterm. For a reduced version of the model, in which the gauge fields are constrained to the trivial orbit, we show that there are no species doublers, and that the fermion spectrum contains only the desired states in the continuum limit, namely charged left-handed (LH) fermions and neutral right-handed (RH) fermions.

  11. Fixed-target physics at LHCb

    CERN Document Server

    Maurice, Emilie Amandine

    2017-01-01

    The LHCb experiment has the unique possibility, among the LHC experiments, to be operated in fixed target mode, using its internal gas target SMOG. The energy scale achievable at the LHC and the excellent detector capabilities for vertexing, tracking and particle identification allow a wealth of measurements of great interest for cosmic ray and heavy ions physics. We report the first measurements made in this configuration: the measurement of antiproton production in proton-helium collisions and the measurements of open and hidden charm production in proton-argon collisions at $\\sqrt{s_\\textrm{NN}} =$ 110 GeV.

  12. The universal cardinal ordering of fixed points

    Energy Technology Data Exchange (ETDEWEB)

    San Martin, Jesus [Departamento de Matematica Aplicada, E.U.I.T.I, Universidad Politecnica de Madrid, Ronda de Valencia 3, 28012 Madrid (Spain); Departamento de Fisica Matematica y Fluidos, U.N.E.D. Senda del Rey 9, 28040 Madrid (Spain); Moscoso, Ma Jose [Departamento de Matematica Aplicada, E.U.I.T.I, Universidad Politecnica de Madrid, Ronda de Valencia 3, 28012 Madrid (Spain); Gonzalez Gomez, A. [Departamento de Matematica Aplicada a los Recursos Naturales, E.T. Superior de Ingenieros de Montes, Universidad Politecnica de Madrid, 28040 Madrid (Spain)], E-mail: antonia.gonzalez@upm.es

    2009-11-30

    We present the theorem which determines, by a permutation, the cardinal ordering of fixed points for any orbit of a period doubling cascade. The inverse permutation generates the orbit and the symbolic sequence of the orbit is obtained as a corollary. Interestingly enough, it is important to point that this theorem needs no previous information about any other orbit; also the cardinal ordering is achieved automatically with no need to compare numerical values associated with every point of the orbit (as would be the case if kneading theory were used)

  13. Fixed points and controllability in delay systems

    Directory of Open Access Journals (Sweden)

    2006-01-01

    Full Text Available Schaefer's fixed point theorem is used to study the controllability in an infinite delay system x ′ ( t = G ( t , x t + ( B u ( t . A compact map or homotopy is constructed enabling us to show that if there is an a priori bound on all possible solutions of the companion control system x ′ ( t = λ [ G ( t , x t + ( B u ( t ] , 0 < λ < 1 , then there exists a solution for λ = 1 . The a priori bound is established by means of a Liapunov functional or applying an integral inequality. Applications to integral control systems are given to illustrate the approach.

  14. [Fixed appliances current state of the art].

    Science.gov (United States)

    Droschl, H; Eskici, A; Bantleon, H P; Muchitsch, A P

    1989-11-01

    Recent advances in fixed appliances are reviewed and discussed. These include cosmetically more appealing brackets (ceramic, lingual); new wires (nickel-titanium and titanium-molybdenum alloys); new biomechanical approaches (accurate computation of forces and torques according to Burstone resulting in the use of new mechanical concepts); experiences in the treatment of transplanted teeth made in the past 15 years; new approaches to the orthodontic finish (implementation of Andrews' "six keys to normal occlusion" with straight wires, accurate positioning of brackets, and gnathological positioners). Cases will be demonstrated.

  15. Chemical Separation of Fixed Tissue Using Thermolysin

    Directory of Open Access Journals (Sweden)

    Anahita Dua

    2013-01-01

    Full Text Available Thermolysin is a metallopeptidase used to cleave peptide bonds at specific junctions. It has previously been used to cleave specific amino acid sequences found at the junction of the sensory epithelium and underlying stroma of unfixed otolithic organs of the vestibular system. We have used thermolysin to separate sensory epithelium from the underlying stroma in fixed cristae ampullares of mouse, rat, gerbil, guinea pig, chinchilla, and tree squirrel, thus removing the saddle-shaped curvature of the sensory organ and creating a flattened sensory epithelium preparation. This permits visualization of the entire sensory organ in a single mount and facilitates proper morphometric analysis.

  16. Fixed kernel regression for voltammogram feature extraction

    Science.gov (United States)

    Acevedo Rodriguez, F. J.; López-Sastre, R. J.; Gil-Jiménez, P.; Ruiz-Reyes, N.; Maldonado Bascón, S.

    2009-12-01

    Cyclic voltammetry is an electroanalytical technique for obtaining information about substances under analysis without the need for complex flow systems. However, classifying the information in voltammograms obtained using this technique is difficult. In this paper, we propose the use of fixed kernel regression as a method for extracting features from these voltammograms, reducing the information to a few coefficients. The proposed approach has been applied to a wine classification problem with accuracy rates of over 98%. Although the method is described here for extracting voltammogram information, it can be used for other types of signals.

  17. Holographic non-Fermi-liquid fixed points.

    Science.gov (United States)

    Faulkner, Tom; Iqbal, Nabil; Liu, Hong; McGreevy, John; Vegh, David

    2011-04-28

    Techniques arising from string theory can be used to study assemblies of strongly interacting fermions. Via this 'holographic duality', various strongly coupled many-body systems are solved using an auxiliary theory of gravity. Simple holographic realizations of finite density exhibit single-particle spectral functions with sharp Fermi surfaces, of a form distinct from those of the Landau theory. The self-energy is given by a correlation function in an infrared (IR) fixed-point theory that is represented by a two-dimensional anti de Sitter space (AdS(2)) region in the dual gravitational description. Here, we describe in detail the gravity calculation of this IR correlation function.

  18. CERN's Fixed Target Primary Ion Programme

    CERN Document Server

    Manglunki, Django; Axensalva, Jerome; Bellodi, Giulia; Blas, Alfred; Bodendorfer, Michael; Bohl, Thomas; Cettour-Cave, Stephane; Cornelis, Karel; Damerau, Heiko; Efthymiopoulos, Ilias; Fabich, Adrian; Ferreira Somoza, Jose; Findlay, Alan; Freyermuth, Pierre; Gilardoni, Simone; Hancock, Steven; Holzer, Eva Barbara; Jensen, Steen; Kain, Verena; Küchler, Detlef; Lombardi, Alessandra; Michet, Alice; O'Neil, Michael; Pasinelli, Sergio; Scrivens, Richard; Steerenberg, Rende; Tranquille, Gerard

    2016-01-01

    The renewed availability of heavy ions at CERN for the needs of the LHC programme has triggered the interest of the fixed-target community. The project, which involves sending several species of primary ions at various energies to the North Area of the Super Proton Synchrotron, has now entered its operational phase. The first argon run, with momenta ranging from 13 AGeV/c to 150 AGeV/c, took place from February 2015 to April 2015. This paper presents the status of the project, the performance achieved thus far and an outlook on future plans.

  19. MEIR-KEELER TYPE CONTRACTIONS FOR TRIPLED FIXED POINTS

    Institute of Scientific and Technical Information of China (English)

    Hassen Aydi; Erdal Karapinar; Calogero Vetro

    2012-01-01

    In 2011,Berinde and Borcut [6] introduced the notion of tripled fixed point in partially ordered metric spaces.In our paper,we give some new tripled fixed point theorems by using a generalization of Meir-Keeler contraction.

  20. A Dual of the Compression-Expansion Fixed Point Theorems

    Directory of Open Access Journals (Sweden)

    Henderson Johnny

    2007-01-01

    Full Text Available This paper presents a dual of the fixed point theorems of compression and expansion of functional type as well as the original Leggett-Williams fixed point theorem. The multi-valued situation is also discussed.

  1. The Mapping Synthesis of Ternary Functions under Fixed Polarities

    Institute of Scientific and Technical Information of China (English)

    陈偕雄; 吴浩敏

    1993-01-01

    This paper proposes a mapping method simplifying the Reed-Muller expansion(“RM expansion”)of a ternary function under fixed polarities and the transformation of the RM expansion coefficients with different fixed polarities.

  2. Fixed Points for Pseudocontractive Mappings on Unbounded Domains

    Directory of Open Access Journals (Sweden)

    García-Falset Jesús

    2010-01-01

    Full Text Available We give some fixed point results for pseudocontractive mappings on nonbounded domains which allow us to obtain generalizations of recent fixed point theorems of Penot, Isac, and Németh. An application to integral equations is given.

  3. Fixed Costs and Asset Market Participation Fixed Costs and Asset Market Participation

    Directory of Open Access Journals (Sweden)

    Harold H. Zhang

    2000-03-01

    Full Text Available This paper investigates the effects of fixed costs on investor's decision of asset market participation. The model features a continuum of agents with heterogeneous initial wealth and attitude toward risk. We show that under certain conditions there exists a unique competitive equilibrium in which investors optimally choose to stay in autarky, participate just in the riskless asset market or in both the riskless and the risky asset markets. The model is calibrated based on earnings profile from the U.S. We find that using fixed costs that are comparable to the current commission charged by brokers the model can generate participation patterns similar to observed ones. Further, we find participation rates to be very sensitive to the costs differentials associated with entering the risky asset market while relatively less sensitive to the overall levels of fixed costs. Finally, we find that costs make it even harder for dynamic models to replicate the risk free rate and in that sense deepen that puzzle. This paper investigates the effects of fixed costs on investor's decision of asset market participation. The model features a continuum of agents with heterogeneous initial wealth and attitude toward risk. We show that under certain conditions there exists a unique competitive equilibrium in which investors optimally choose to stay in autarky, participate just in the riskless asset market or in both the riskless and the risky asset markets. The model is calibrated based on earnings profile from the U.S. We find that using fixed costs that are comparable to the current commission charged by brokers the model can generate participation patterns similar to observed ones. Further, we find participation rates to be very sensitive to the costs differentials associated with entering the risky asset market while relatively less sensitive to the overall levels of fixed costs. Finally, we find that costs make it even harder for dynamic models to replicate

  4. Long-term evaluation of cantilevered versus fixed-fixed resin-bonded fixed partial dentures for missing maxillary incisors.

    Science.gov (United States)

    Botelho, Michael G; Chan, Alex W K; Leung, Nic C H; Lam, Walter Y H

    2016-02-01

    To evaluate the long-term longevity and patient-reported outcomes of two-unit cantilevered (CL2) and three-unit fixed-fixed (FF3) resin-bonded fixed partial dentures (RBFPDs) for the replacement of a maxillary permanent incisor. Twenty-eight subjects were randomly assigned to receive either a CL2 or FF3 RBFPD placed by one operator. Prosthesis longevity was determined by clinical examination and history. Success was defined as absence of complications requiring intervention and survival as retention of the original prosthesis in mouth. Subjects' satisfaction was assessed using visual analogue scale (VAS) and oral health-related quality of life (OHRQoL) using Oral Health Impact Profile (OHIP-49). Outcomes were analysed with t-test/Mann-Whitney U test, chi-square and log-rank test at significance level α=0.05. Twenty-two subjects were reviewed. Thirteen of fifteen CL2 and ten of fourteen FF3 RBFPDs were examined (79.3 percent response rate) with a mean service life of 216.5±20.8months. All CL2 RBFPDs survived with no complications while only 10 percent of FF3 experienced no complications and only 50 percent of them survived (both P=0.000). CL2 had a significantly better success and survival rate than FF3 (P=0.000 and P=0.009, respectively). There was no significant difference in subjects' satisfaction and OHRQoL apart from CL2 group subjects had a higher satisfaction in cleaning of the prosthesis (84.1±13.6) than FF3 group (72.6±11.7) (P=0.05). Two-unit cantilevered RBFPDs were observed to have a significantly better success and survival than the FF3 design for the replacement of a maxillary incisor. Good patient-reported outcomes have been found for RBFPDs in single-tooth replacement in aesthetic zone. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. 47 CFR 22.1031 - Temporary fixed stations.

    Science.gov (United States)

    2010-10-01

    ... MOBILE SERVICES Offshore Radiotelephone Service § 22.1031 Temporary fixed stations. The FCC may, upon proper application therefor, authorize the construction and operation of temporary fixed stations in the... the United States and Mexico must not be carried using a temporary fixed station without...

  6. Fixed Points of -Endomorphisms of a Free Metabelian Lie Algebra

    Indian Academy of Sciences (India)

    Naime Ekici; Demet Parlak Sönmez

    2011-11-01

    Let be a free metabelian Lie algebra of finite rank at least 2. We show the existence of non-trivial fixed points of an -endomorphism of and give an algorithm detecting them. In particular, we prove that the fixed point subalgebra Fix of an -endomorphism of is not finitely generated.

  7. GPU implementation of a Landau gauge fixing algorithm

    CERN Document Server

    Cardoso, Nuno; Oliveira, Orlando; Bicudo, Pedro

    2012-01-01

    We discuss how the steepest descent method with Fourier acceleration for Laudau gauge fixing in lattice SU(3) simulations can be implemented using CUDA. The scaling of the gauge fixing code was investigated using a Tesla C2070 Fermi architecture, and compared with a parallel CPU gauge fixing code.

  8. 33 CFR 118.65 - Lights on fixed bridges.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Lights on fixed bridges. 118.65 Section 118.65 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES BRIDGE LIGHTING AND OTHER SIGNALS § 118.65 Lights on fixed bridges. (a) Each fixed bridge span over a...

  9. Classification system for conventional crown and fixed partial denture failures.

    Science.gov (United States)

    Manappallil, John Joy

    2008-04-01

    The dental literature is replete with reports on the many aspects of failure encountered with traditional fixed prosthodontic treatment, including longitudinal survival studies of crowns and fixed partial dentures and reasons for failures. However, criteria for grading or classifying the type and severity of these failures are inadequate. A classification system for conventional fixed prosthodontic failures based on severity is presented.

  10. 46 CFR 28.320 - Fixed gas fire extinguishing systems.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Fixed gas fire extinguishing systems. 28.320 Section 28..., 1991, and That Operate With More Than 16 Individuals on Board § 28.320 Fixed gas fire extinguishing...) or more in length must be fitted with a fixed gas fire extinguishing system in the following...

  11. On Fixed Points of Linguistic Dynamic Systems

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Linguistic dynamic systems (LDS) are dynamic systems whose state variables are generalized from numbers to words. Generally speaking, LDS can model all evolving processes in word domains by using linguistic evolving laws which are naturally the linguistic extension of evolving laws in numbers. There are two kinds of LDS; namely, type-I and type-II LDS. If the word domain is modeled by fuzzy sets, then the evolving laws of a type-I LDS are constructed by applying the fuzzy extension principle to those of its conventional counterpart. On the other hand, the evolving laws of a type-II LDS are modeled by fuzzy if/then rules. Note that the state spaces of both type-I and type-II LDSs are word continuum. However, in practice, the representation of the state space of a type-II LDS consists of finite number while its computation actually involves a word continuum. In this paper, the existence of fixed points of type-II LDS is studied based on point-to-fuzzy-set mappings. The properties of the fixed point of type-II LDS are also studied. In addition, linguistic controllers are designed to control type-II LDS to goal states specified in words.

  12. Duan's fixed point theorem: Proof and generalization

    Directory of Open Access Journals (Sweden)

    Martin Arkowitz

    2006-02-01

    Full Text Available Let X be an H-space of the homotopy type of a connected, finite CW-complex, f:X→X any map and pk:X→X the kth power map. Duan proved that pkf:X→X has a fixed point if k≥2. We give a new, short and elementary proof of this. We then use rational homotopy to generalize to spaces X whose rational cohomology is the tensor product of an exterior algebra on odd dimensional generators with the tensor product of truncated polynomial algebras on even dimensional generators. The role of the power map is played by a θ-structure μθ:X→X as defined by Hemmi-Morisugi-Ooshima. The conclusion is that μθf and fμθ each has a fixed point.

  13. Regulatory requirements for marketing fixed dose combinations

    Directory of Open Access Journals (Sweden)

    B G Jayasheel

    2010-01-01

    Full Text Available The development of fixed-dose combinations (FDCs is becoming increasingly important from a public health perspective. FDCs have advantages when there is an identifiable patient population for whom treatment with a particular combination of actives in a fixed ratio is safe and effective and when all of the actives contribute to the overall therapeutic effect. Such combinations of drugs are particularly useful in the management of chronic diseases. In addition, there can be real clinical benefits in the form of increased efficacy and/or a reduced incidence of adverse effects. Additional advantages of FDCs are potentially lower costs of manufacturing compared to the costs of producing separate products administered concurrently, simpler logistics of distribution and reduced development of resistance in the case of antimicrobials. Above all, FDC therapy reduces pill burden and improves medication compliance. Although, FDCs seem to be ideal under certain pre-defined circumstances, if a dosing adjustment is warranted, there may not be an FDC available in the most appropriate strength for the patient and if an adverse drug reaction occurs from using an FDC, it may be difficult to identify the active ingredient responsible for causing the reaction. Appendix VI of Schedule Y (Drugs & Cosmetics Rules 1945, India states the requirements for marketing approval of various types of FDCs. The same is further elaborated in this article to provide a detailed guidance including the clinical trial requirements. However, the heterogeneity of the therapeutic field makes it difficult to develop a standard guidance document.

  14. Random and fixed effects in plant genetics.

    Science.gov (United States)

    Cockerham, C C

    1980-05-01

    A general model for any type of genetic entry is developed which takes into account both the factorial model of gene effects and the ancestral sources, whether inbred lines or outbred varieties, of the genes.Utilizing the model, various genetic designs of fixed entries are explored for the estimation of genetic effects and the testing of genetic hypotheses. These designs consisted of generation means - parents, crosses, various types of backcrosses, and so on - stemming from one or more pairs of parents, and of hybrid combinations from factorial mating designs. Limitations, from the standpoint of genetic effects that can be estimated and genetic hypotheses that can be tested, are developed in considerable detail.When entries from the factorial mating designs are considered to be random, attention is focused on the estimation of genetic variances, rather than effects, and on the concomitant changes in the tests of genetic hypotheses. While there is considerable improvement over fixed entries in the number of types of genetic variances that can be estimated, and of genetic hypotheses that can be tested, they are still very limited in contrast to what would be most desirable.

  15. Fixed Drug Eruption due to Achiote Dye

    Directory of Open Access Journals (Sweden)

    Ian Tattersall

    2016-01-01

    Full Text Available Fixed drug eruption (FDE is a localized type IV sensitivity reaction to a systemically introduced allergen. It usually occurs as a result of new medication, making identification and avoidance of the trigger medication straightforward; however, in a rare subset of cases no pharmacological source is identified. In such cases, the causative agent is often a food or food additive. In this report we describe a case of a FDE in a 12-year-old girl recently immigrated to the United States from Ecuador who had no medication exposure over the course of her illness. Through an exhaustive patient history and literature review, we were able to hypothesize that her presentation was caused by a dietary change of the natural achiote dye used in the preparation of yellow rice to a locally available commercial dye mix containing tartrazine, or Yellow 5, which has previously been implicated in both systemic hypersensitivity reactions and specifically in FDE. This report adds to the small body of available literature on non-pharmacological fixed hypersensitivity eruptions and illustrates an effective approach to the management of such a presentation when history is not immediately revealing.

  16. Fixed Drug Eruption due to Achiote Dye

    Science.gov (United States)

    Tattersall, Ian; Reddy, Bobby Y.

    2016-01-01

    Fixed drug eruption (FDE) is a localized type IV sensitivity reaction to a systemically introduced allergen. It usually occurs as a result of new medication, making identification and avoidance of the trigger medication straightforward; however, in a rare subset of cases no pharmacological source is identified. In such cases, the causative agent is often a food or food additive. In this report we describe a case of a FDE in a 12-year-old girl recently immigrated to the United States from Ecuador who had no medication exposure over the course of her illness. Through an exhaustive patient history and literature review, we were able to hypothesize that her presentation was caused by a dietary change of the natural achiote dye used in the preparation of yellow rice to a locally available commercial dye mix containing tartrazine, or Yellow 5, which has previously been implicated in both systemic hypersensitivity reactions and specifically in FDE. This report adds to the small body of available literature on non-pharmacological fixed hypersensitivity eruptions and illustrates an effective approach to the management of such a presentation when history is not immediately revealing. PMID:26933409

  17. Fixed Drug Eruption due to Achiote Dye.

    Science.gov (United States)

    Tattersall, Ian; Reddy, Bobby Y

    2016-01-01

    Fixed drug eruption (FDE) is a localized type IV sensitivity reaction to a systemically introduced allergen. It usually occurs as a result of new medication, making identification and avoidance of the trigger medication straightforward; however, in a rare subset of cases no pharmacological source is identified. In such cases, the causative agent is often a food or food additive. In this report we describe a case of a FDE in a 12-year-old girl recently immigrated to the United States from Ecuador who had no medication exposure over the course of her illness. Through an exhaustive patient history and literature review, we were able to hypothesize that her presentation was caused by a dietary change of the natural achiote dye used in the preparation of yellow rice to a locally available commercial dye mix containing tartrazine, or Yellow 5, which has previously been implicated in both systemic hypersensitivity reactions and specifically in FDE. This report adds to the small body of available literature on non-pharmacological fixed hypersensitivity eruptions and illustrates an effective approach to the management of such a presentation when history is not immediately revealing.

  18. Fixed Dose Combination for TB treatment

    Directory of Open Access Journals (Sweden)

    Tjandra Y. Aditama

    2003-06-01

    Full Text Available According to the World Health Organization, a third of the world’s population is infected with tuberculosis. The disease is responsible for nearly 2 million deaths each year and over 8 million were developing active diseases. Moreover, according to WHO (2000, tuberculosis deaths are estimated to increase to 35 million between 2000-2020. The majority of tuberculosis patients worldwide are still treated with single drugs, or with 2-drug fixed-dose combinations (FDCs. To improve tuberculosis treatment, 2- and 3-drug FDCs were recommended by the World Health Organization (WHO as part of the DOTS strategy. Since 1999 a 4-drug FDC was included on the WHO Model List of Essential Drugs. Today, FDCs are important tools to further improve the quality of care for people with TB, and accelerate DOTS expansion to reach the global TB control targets. Fixed dose combination TB drugs could simplifies both treatment and management of drug supply, and may prevent the emergence of drug resistance .Prevention of drug resistance is just one of the potential benefits of the use of FDCs. FDCs simplify administration of drugs by reducing the number of pills a patient takes each day and decreasing the risk of incorrect prescriptions. Most tuberculosis patients need only take 3–4 FDCs tablets per day during the intensive phase of treatment, instead of the 15–16 tablets per day that is common with single-drug formulations It is much simpler to explain to patients that they need to take four tablets of the same type and colour, rather than a mixture of tablets of different shapes, colours and sizes. Also, the chance of taking an incomplete combination of drugs is eliminated, since the four essential drugs are combined into one tablet. FDCs are also simpler for care-givers as they minimize the risk of confusion. Finally, drug procurement, in all its components (stock management, shipping, distribution, is simplified by FDCs. Adverse reactions to drugs are not more

  19. Competition and facilitation between unicellular nitrogen-fixing cyanobacteria and non-nitrogen-fixing phytoplankton species

    NARCIS (Netherlands)

    Agawin, N.S.; Rabouille, S.; Veldhuis, M.; Servatius, L.; Hol, S.; van Overzee, H.M.J.; Huisman, J.

    2007-01-01

    Abstract: Recent discoveries show that small unicellular nitrogen-fixing cyanobacteria are more widespread than previously thought and can make major contributions to the nitrogen budget of the oceans. We combined theory and experiments to investigate competition for nitrogen and light between these

  20. Biofilm formation enables free-living nitrogen-fixing rhizobacteria to fix nitrogen under aerobic conditions.

    Science.gov (United States)

    Wang, Di; Xu, Anming; Elmerich, Claudine; Ma, Luyan Z

    2017-07-01

    The multicellular communities of microorganisms known as biofilms are of high significance in agricultural setting, yet it is largely unknown about the biofilm formed by nitrogen-fixing bacteria. Here we report the biofilm formation by Pseudomonas stutzeri A1501, a free-living rhizospheric bacterium, capable of fixing nitrogen under microaerobic and nitrogen-limiting conditions. P. stutzeri A1501 tended to form biofilm in minimal media, especially under nitrogen depletion condition. Under such growth condition, the biofilms formed at the air-liquid interface (termed as pellicles) and the colony biofilms on agar plates exhibited nitrogenase activity in air. The two kinds of biofilms both contained large ovoid shape 'cells' that were multiple living bacteria embedded in a sac of extracellular polymeric substances (EPSs). We proposed to name such large 'cells' as A1501 cyst. Our results suggest that the EPS, especially exopolysaccharides enabled the encased bacteria to fix nitrogen while grown under aerobic condition. The formation of A1501 cysts was reversible in response to the changes of carbon or nitrogen source status. A1501 cyst formation depended on nitrogen-limiting signaling and the presence of sufficient carbon sources, yet was independent of an active nitrogenase. The pellicles formed by Azospirillum brasilense, another free-living nitrogen-fixing rhizobacterium, which also exhibited nitrogenase activity and contained the large EPS-encapsuled A1501 cyst-like 'cells'. Our data imply that free-living nitrogen-fixing bacteria could convert the easy-used carbon sources to exopolysaccharides in order to enable nitrogen fixation in a natural aerobic environment.

  1. Fixed drug eruption due to levocetirizine

    Directory of Open Access Journals (Sweden)

    Ratinder Jhaj

    2016-01-01

    Full Text Available A fixed drug eruption (FDE is a cutaneous adverse drug reaction due to Type IV or delayed cell-mediated hypersensitivity. Antihistamines, which antagonize the action of histamine during an allergic reaction by blocking the H 1 histamine receptors, are used routinely for the treatment of various allergic disorders such as urticaria, eczemas, and also in itchy lesions of skin like scabies.Levocetirizine, an active (R-enantiomer of cetirizine, is a newer or second generation antihistamine, with more specific actions and fewer side effects, including cutaneous reactions. FDE due to levocetirizine as well as with cetirizine are rare. We report a case of levocetirizine induced FDE in a 49-year-old male patient with scabies. The patient had a history of cetirizine induced FDE in the past.

  2. Recursive double-size fixed precision arithmetic

    CERN Document Server

    Chabot, Christophe; Fousse, Laurent; Giorgi, Pascal

    2011-01-01

    This work is a part of the SHIVA (Secured Hardware Immune Versatile Architecture) project whose purpose is to provide a programmable and reconfigurable hardware module with high level of security. We propose a recursive double-size fixed precision arithmetic called RecInt. Our work can be split in two parts. First we developped a C++ software library with performances comparable to GMP ones. Secondly our simple representation of the integers allows an implementation on FPGA. Our idea is to consider sizes that are a power of 2 and to apply doubling techniques to implement them efficiently: we design a recursive data structure where integers of size 2^k, for k>k0 can be stored as two integers of size 2^{k-1}. Obviously for k<=k0 we use machine arithmetic instead (k0 depending on the architecture).

  3. [Update on protein analysis of fixed tissues].

    Science.gov (United States)

    Becker, K-F; Berg, D; Malinowsky, K; Wolff, C; Ergin, B; Meding, S; Walch, A; Höfler, H

    2010-10-01

    Tissue samples have been routinely used for decades to distinguish healthy from diseased tissue in histopathological characterization. While nucleic acid-based methodologies have been successfully in use for many years, protein-based techniques, in contrast, are at a very early stage (with the exception of immunohistochemistry). One reason for this delay may be that the scientific community has long thought that formalin-fixed and paraffin embedded (FFPE) tissues are unfit for protein analysis. However, recent reports demonstrate that many protein methods that are routinely used for frozen tissues can also be applied for FFPE tissues, including Western blot, protein microarray, matrix-assisted laser desorption/ionization (MALDI) imaging and 2D gel electrophoresis. The present article provides an overview of recent developments in this field, focussing particular attention on quantitative analysis and high throughput technologies that have the potential to be integrated into the routine workflow of clinical pathology laboratories.

  4. Fixed bed gasification of solid biomass fuels

    Energy Technology Data Exchange (ETDEWEB)

    Haavisto, I. [Condens Oy, Haemeenlinna (Finland)

    1996-12-31

    Fixed bed biomass gasifiers are feasible in the effect range of 100 kW -10 MW. Co-current gasification is available only up to 1 MW for technical reasons. Counter-current gasifiers have been used in Finland and Sweden for 10 years in gasification heating plants, which are a combination of a gasifier and an oil boiler. The plants have proved to have a wide control range, flexible and uncomplicated unmanned operation and an excellent reliability. Counter-current gasifiers can be applied for new heating plants or for converting existing oil and natural gas boilers into using solid fuels. There is a new process development underway, aiming at motor use of the producer gas. The development work involves a new, more flexible cocurrent gasifier and a cleaning step for the counter-current producer gas. (orig.)

  5. Equilibria, Fixed Points, and Complexity Classes

    CERN Document Server

    Yannakakis, Mihalis

    2008-01-01

    Many models from a variety of areas involve the computation of an equilibrium or fixed point of some kind. Examples include Nash equilibria in games; market equilibria; computing optimal strategies and the values of competitive games (stochastic and other games); stable configurations of neural networks; analysing basic stochastic models for evolution like branching processes and for language like stochastic context-free grammars; and models that incorporate the basic primitives of probability and recursion like recursive Markov chains. It is not known whether these problems can be solved in polynomial time. There are certain common computational principles underlying different types of equilibria, which are captured by the complexity classes PLS, PPAD, and FIXP. Representative complete problems for these classes are respectively, pure Nash equilibria in games where they are guaranteed to exist, (mixed) Nash equilibria in 2-player normal form games, and (mixed) Nash equilibria in normal form games with 3 (or ...

  6. Fixed point theorems for generalized Lipschitzian semigroups

    Directory of Open Access Journals (Sweden)

    Jong Soo Jung

    2001-01-01

    semigroup of K into itself, that is, for s∈G, ‖Tsx−Tsy‖≤as‖x−y‖+bs(‖x−Tsx‖+‖y−Tsy‖+cs(‖x−Tsy‖+‖y−Tsx‖, for x,y∈K where as,bs,cs>0 such that there exists a t1∈G such that bs+cs<1 for all s≽t1. It is proved that if there exists a closed subset C of K such that ⋂sco¯{Ttx:t≽s}⊂C for all x∈K, then with [(α+βp(αp⋅2p−1−1/(cp−2p−1βp⋅Np]1/p<1 has a common fixed point, where α=lim sups(as+bs+cs/(1-bs-cs and β=lim sups(2bs+2cs/(1-bs-cs.

  7. Lifting fixed points of completely positive semigroups

    CERN Document Server

    Prunaru, Bebe

    2011-01-01

    Let $\\{\\phi_s\\}_{s\\in S}$ be a commutative semigroup of completely positive and contractive linear maps acting on a von Neumann algebra $N$. Assume there exists a semigroup $\\{\\alpha_s\\}_{s\\in S}$ of *-endomorphisms of some larger von Neumann algebra $M\\supset N$ and a projection $p\\in M$ with $N=pMp$ such that $\\alpha_s(1-p)\\le 1-p$ for every $s\\in S$ and $\\phi_s(y)=p\\alpha_s(y)p$ for all $y\\in N$. If $\\inf_{s\\in S}\\alpha_s(1-p)=0$ then we show that the map $E:M\\to N$ defined by $E(x)=pxp$ for $x\\in M$ induces a complete isometry between the fixed point spaces of $\\{\\alpha_s\\}_{s\\in S}$ and $\\{\\phi_s\\}_{s\\in S}$.

  8. Galvanic gold plating for fixed dental prosthesis.

    Science.gov (United States)

    Ozcelik, Tuncer Burak; Yilmaz, Burak

    2013-07-01

    Metal ceramic partial fixed dental prostheses have been commonly used for the replacement of missing teeth for many years. Because of an increase in the price of gold, base metal alloys have been the choice of alloy for the fabrication of metal ceramic restorations in many dental clinics. Some major disadvantages of base metals are their corrosion and the dark coloration they may cause at the crown margins. This article describes a galvanic gold-plating technique, which is used to minimize corrosion and improve the esthetics of metal ceramic restorations fabricated with Cr-Co base metal alloys. This technique involves the deposition of a 6 μm to 8 μm 24 K gold layer directly onto the Cr-Co cast prosthesis framework. The technique improves metal surface properties, making them more biocompatible and usable, however, requires additional equipment and experienced laboratory technicians. Clinical studies should be performed to corroborate the long term success of this technique.

  9. On Krasnoselskii's Cone Fixed Point Theorem

    Directory of Open Access Journals (Sweden)

    Man Kam Kwong

    2008-04-01

    Full Text Available In recent years, the Krasnoselskii fixed point theorem for cone maps and its many generalizations have been successfully applied to establish the existence of multiple solutions in the study of boundary value problems of various types. In the first part of this paper, we revisit the Krasnoselskii theorem, in a more topological perspective, and show that it can be deduced in an elementary way from the classical Brouwer-Schauder theorem. This viewpoint also leads to a topology-theoretic generalization of the theorem. In the second part of the paper, we extend the cone theorem in a different direction using the notion of retraction and show that a stronger form of the often cited Leggett-Williams theorem is a special case of this extension.

  10. Fixed target experiments at the Fermilab Tevatron

    CERN Document Server

    Gutierrez, Gaston

    2014-01-01

    This paper presents a review of the study of Exclusive Central Production at a Center of Mass energy of $\\sqrt{s}=40$ GeV at the Fermilab Fixed Target program. In all reactions reviewed in this paper, protons with an energy of 800 GeV were extracted from the Tevatron accelerator at Fermilab and directed to a Liquid Hydrogen target. The states reviewed include $\\pi^+\\pi^-$, $K^0_s K^0_s$, $ K^0_sK^\\pm\\pi^\\mp$, $\\phi\\phi$ and $D^{*\\pm}$. Partial Wave Analysis results will be presented on the light states but only the cross section will be reviewed in the diffractive production of $D^{*\\pm}$

  11. Fixed Points for Stochastic Open Chemical Systems

    CERN Document Server

    Malyshev, V A

    2011-01-01

    In the first part of this paper we give a short review of the hierarchy of stochastic models, related to physical chemistry. In the basement of this hierarchy there are two models --- stochastic chemical kinetics and the Kac model for Boltzman equation. Classical chemical kinetics and chemical thermodynamics are obtained as some scaling limits in the models, introduced below. In the second part of this paper we specify some simple class of open chemical reaction systems, where one can still prove the existence of attracting fixed points. For example, Michaelis\\tire Menten kinetics belongs to this class. At the end we present a simplest possible model of the biological network. It is a network of networks (of closed chemical reaction systems, called compartments), so that the only source of nonreversibility is the matter exchange (transport) with the environment and between the compartments. Keywords: chemical kinetics, chemical thermodynamics, Kac model, mathematical biology

  12. Pseudoephedrine may cause "pigmenting" fixed drug eruption.

    Science.gov (United States)

    Ozkaya, Esen; Elinç-Aslan, Meryem Sevinç

    2011-05-01

    Fixed drug eruption (FDE) is a distinctive drug eruption characterized by recurrent well-defined lesions in the same location each time the responsible drug is taken. Two different clinical forms have been described: the common classic pigmenting form and the rare nonpigmenting form. Nonpigmenting FDE is mainly characterized by symmetrical large erythematous plaques and the dermal histopathologic reaction pattern. Pseudoephedrine is known as the major inducer of nonpigmenting FDE. Pigmenting FDE from pseudoephedrine has not been reported previously. Here, the first case of pseudoephedrine-induced pigmenting FDE is reported, showing the characteristic features of classic pigmenting FDE such as asymmetry, normal-sized lesions, and the epidermodermal histopathologic reaction pattern. Moreover, a positive occlusive patch-test reaction to pseudoephedrine could be demonstrated on postlesional FDE skin for the first time.

  13. Meprobamate-induced fixed drug eruption.

    Science.gov (United States)

    Zaïem, Ahmed; Kaabi, Widd; Badri, Talel; Lakhoua, Ghozlane; Sahnoun, Rym; Kastalli, Sarrah; Daghfous, Riadh; Lakhal, Mohamed; El Aidli, Sihem

    2014-01-01

    Meprobamate is usually a safe drug prescribed for anxiety disorders. Fixed drug eruption (FDE) is an exceptional cutaneous adverse effect of this drug. We report a case of FDE induced by meprobamate with positive patch test. A 22-year-old woman was prescribed for depression meprobamate, aceprometazine, valpromide and lorazepam. On the second day of treatment, the patient presented red erythematous and pruriginous plaques in the limbs and the face. After stopping the previous treatment, the patient's lesions resolved completely within 3 weeks with residual pigmentation. One month later, patch tests were performed and were positive to meprobamate. Exceptional cases of FDE were reported in literature with meprobamate. None has reported the use of patch test to confirm the diagnosis.

  14. Steiner trees for fixed orientation metrics

    DEFF Research Database (Denmark)

    Brazil, Marcus; Zachariasen, Martin

    2009-01-01

    We consider the problem of constructing Steiner minimum trees for a metric defined by a polygonal unit circle (corresponding to s = 2 weighted legal orientations in the plane). A linear-time algorithm to enumerate all angle configurations for degree three Steiner points is given. We provide...... a simple proof that the angle configuration for a Steiner point extends to all Steiner points in a full Steiner minimum tree, such that at most six orientations suffice for edges in a full Steiner minimum tree. We show that the concept of canonical forms originally introduced for the uniform orientation...... metric generalises to the fixed orientation metric. Finally, we give an O(s n) time algorithm to compute a Steiner minimum tree for a given full Steiner topology with n terminal leaves....

  15. Do foliar endophytic bacteria fix nitrogen?

    Science.gov (United States)

    Kueppers, L. M.; Moyes, A. B.; Frank, C.; Pett-Ridge, J.; Carper, D.; Vandehey, N.; O'Neil, J.; Dekas, A.

    2015-12-01

    Endophytic microorganisms - bacteria and fungi that live inside healthy plant tissue - are a relatively unexplored source of functional diversity in natural ecosystems. Prior to modern sequencing technology, detecting uncultured endophytic bacteria and assessing their putative functions was challenging. However, recent work has revealed a remarkable diversity of as yet non-culturable endophytic taxa and is beginning to identify functional roles within plant microbiomes. We recently examined bacterial communities in the foliage of a long-lived, high-elevation conifer species, limber pine (Pinus flexilis), and discovered a community strongly dominated by acetic acid bacteria (Acetobacteraceae), with several taxa closely related to known nitrogen fixers. Given limber pine's status as a pioneer species that is able to grow in low fertility soils, we hypothesized that this bacterial community has a potential functional role in fixing atmospheric nitrogen, providing a source of this limiting nutrient to the host tree. We used the radioisotope 13N2 to confirm that N2 rapidly diffuses into pine needles, where it could potentially be fixed. With an acetylene reduction assay we confirmed nitrogenase enzyme activity inside excised twigs 4 times over a growing season, and estimate potential rates of N2 fixation at 0.1 nmol N2 g needle-1 hr-1. Scaled to the stand level, this N input could be on the order of ~20 mg N m-2 d-1 over a growing season. While these rates are low, the long lifespan of individual trees (~1000 years) makes them biologically meaningful. Still, measured rates of acetylene reduction and bulk 15N2 incorporation are quite variable in space and time. Much work remains to better characterize the plant-microbial interactions in this system, including the rates of nitrogen fixation and their variability over the growing season, across edaphic conditions, among host species, and through plant development; and to determine which community members are responsible

  16. 广州“红层”地质盾构机滚刀磨损与掘进参数特性分析%Characteristic Analysis of Wear of Cutters and Excavation Parameters of Shield Tunneling Machine in Red Beds in Guangzhou

    Institute of Scientific and Technical Information of China (English)

    董汉军; 谭啸峰; 杨钊; 翟世鸿; 杨擎

    2013-01-01

    以广佛地铁12标工程为依托,根据盾构机刀盘的设计参数,给出了不同位置滚刀的允许磨损量。结合现场实测数据,给出了边滚刀磨损的主要原因,并提出了改造方案。结合现场掘进数据,分析了岩层掘进贯入度与刀盘转速的选用原则。研究结果表明:压柱式镶齿滚刀能较好地适用于红层掘进,增加有效掘进1倍以上;红层掘进应选用高贯入度,慢转速的掘进参数,以获得最佳的掘进效率。%Researches in this paper were focused on the construction under Contract Package 12 of Guangzhou-Foshan metro lines. The allowable wear loss of disc cutters in different locations were presented according to the design parameters of the shield cutter head. Combined with the field data, the main reason for the wear of edge discs and modification schemes were given. Based on the site excavation data,the selection principle for rock tunneling penetration and speed of cutter head were analyzed. The results of the researches indicate that the compression column type tungstem-carbide-tipped cutter was quite suitable for tunneling in the red beds, which can increase tunneling efficiency more than doubled. In order to get the best tunneling efficiency,the parameters for tunneling in the red beds with high penetration rate and low speed should be used.

  17. 超声引导下自凝刀射频治疗子宫肌瘤46例临床分析%Clinical analysis on 46 cases with hysteromyoma treated with ultrasound - guided self- clotting cutter radiofrequency

    Institute of Scientific and Technical Information of China (English)

    王永芳; 陈淑华; 徐军

    2011-01-01

    目的:分析超声引导下自凝刀射频治疗子宫肌瘤的临床疗效.方法:回顾性分析2009年3月~2010年2月采用自凝刀手术治疗的46例子宫肌瘤患者的资料.结果:46例患者术中、术后均无手术并发症发生.肌瘤合并月经量增多36例,治愈33例,治愈率91.67%;术后1、3、6个月子宫体积平均缩小率分别为10.39%、42.53%、52.13%,肌瘤体积平均缩小率分别为38.37%、59.38%,68.34%;术后3、6个月子宫体积缩小率与治疗前比较差异均有统计学意义(P<0.05);术后1、3、6个月子宫肌瘤体积缩小率与治疗前比较差异均有统计学意义(P<0.05).结论:超声引导下自凝刀射频治疗子宫肌瘤是一种能保留子宫的微创技术,疗效确切、损伤小、方便、费用低,值得临床推广应用.%Objective: To analyze the clinical efficacy of ultrasound - guided self - clotting cutter radiofrequency in treatment of hysteromyoma. Methods; The data of 46 cases with hysteromyoma who were treated with ultrasound - guided self - clotting cutter radiofrequency in the hospital from March 2009 to February 2010 were analyzed retrospectively. Results; No complications occurred after operation in the 46 cases. 36 cases were found with hysteromyoma combined with menorrhagia, 33 cases were cured, the cure rate was 91. 67%. The average rates of decrease of uterine volume at 1 , 3 and 6 months after operation were 10. 39% , 42. 53% and 52. 13% , respectively; the average rates of decrease of hysteromyoma volume at 1, 3 and 6 months after operation were 38. 37 % , 59. 38% and 68. 34% , respectively; there was significant difference in the average rate of decrease of uterine volume before treatment and after treatment at 3 and 6 months ( P < 0.05); there was significant difference in the average rate of decrease of hysteromyoma volume before treatment and after treatment at 1, 3 and 6 months ( P < 0. 05 ) . Conclusion: Ultrasound - guided self - clotting cutter

  18. 鼻内镜下电动切割器治疗腺样体肥大36例%Endoscopic electric cutters in the treatment of 36 cases of adenoidal hypertrophy

    Institute of Scientific and Technical Information of China (English)

    王静; 吴加亮; 尹霞

    2014-01-01

    目的:探讨鼻内镜下电动切割器治疗腺样体肥大的临床疗效。方法将36例接受腺样体切除术治疗腺样体肥大的患者根据随机数字表法分为观察组与对照组,观察组采用鼻内镜下电动切割器治疗,对照组则采用传统腺样切除术治疗,比较两组治疗效果。结果观察组彻底切除腺样体所需时间为(10.65±2.38)min,术中出血量(28.82±0.98)mL,并发症发生率为0.00%,与对照组比较差异均有统计学意义(t=25.93、31.79,χ2=3.92,均P<0.05);观察组重度疼痛1例,低于对照组的9例(χ2=8.86,P<0.05);观察组总有效率为94.45%,显著高于对照组的55.55%(χ2=7.26,P<0.05)。结论相比于传统腺样体切除术治疗,采用鼻内镜下电动切割器治疗腺样体肥大能在显著减小术中出血量及并发症发生率的同时改善患者疼痛感,提高临床疗效,值得在临床上进一步推广。%Objective To explore the efficacy of endoscopic electric cutters in the treatment of adenoidal hypertrophy .Methods 36 patients who underwent adenoidectomy treatment of adenoid hypertrophy were divided into the observation group and control group according to the random number table .The observation group was taken endo-scopic electric cutters treatment , the control group was taken traditional adenoid removal treatment .The therapeutic effect of the two groups was compared .Results In the observation group,the total time required for removal of the adenoids was (10.65 ±2.38)min,blood loss was (28.82 ±0.98)mL,compared with the control group,there were significant differences(t=25.93,31.79,χ2 =3.92,all P<0.05).In the observation group,there was 1 case had severe pain,but in the control group,there were 9 cases,the difference was significant (χ2 =8.86,P<0.05).In the observation group,the total effective rate was 94.45%,which was significantly higher than 55.55% in

  19. A silicose e o perfil dos lapidários de pedras semipreciosas em Joaquim Felício, Minas Gerais, Brasil Silicosis among semiprecious gem cutters in Joaquim Felício, Minas Gerais State, Brazil

    Directory of Open Access Journals (Sweden)

    Lucille Ribeiro Ferreira

    2008-07-01

    Full Text Available Para conhecer a prevalência de silicose, descrever os perfis clínico, epidemiológico e ocupacional, e estudar as condições de trabalho das oficinas de lapidação, realizou-se estudo transversal de setenta lapidários de pedras semipreciosas de Joaquim Felício, Minas Gerais, Brasil, de abril a dezembro de 2002. Utilizaram-se história ocupacional com questionário respiratório, radiografia de tórax e espirometria. A prevalência de silicose foi de 7,1%. Todos eram do sexo masculino, com média de idade de 21,5 anos e tempo médio de exposição à sílica de 7,1 anos. Todos pertenciam ao setor da economia informal e trabalhavam em oficinas pequenas e rudimentares, sendo o maquinário improvisado e havendo maciça exposição à sílica. Segundo a Classificação Radiológica da Organização Internacional do Trabalho, dos cinco casos de silicose, quatro foram classificados na categoria 1, e um na 3. A silicose em lapidários constitui um sério problema de saúde pública que requer esforços para minimização do risco de adoecimento, por meio da ação de equipes multidisciplinares provenientes de instituições governamentais e não-governamentais, com inserção ativa dos trabalhadores.A cross-sectional study was performed to determine the prevalence of silicosis among semiprecious gem cutters (n = 70 and describe their clinical, epidemiological, and occupational profiles in Joaquim Felício, Minas Gerais State, Brazil, from April to December 2002. Occupational history was used with a respiratory questionnaire, chest x-ray, and spirometry. Silicosis prevalence was 7.1%. All affected individuals were men, with a mean age of 21.5 and mean exposure to silica of 7.1 years. All belonged to the informal economy and had been working at small and rudimentary workshops, using improvised lathes, with intense exposure to silica dust. According to the ILO Radiological Classification, four of the five cases of silicosis were classified as grade 1

  20. Oral health with fixed appliances orthodontics

    Directory of Open Access Journals (Sweden)

    Konta, Brigitte

    2008-03-01

    Full Text Available Orthodontic treatment represents an important fraction in dental interventions. According to other medical methods the question for scientific evidence for the effectiveness of these treatments arises. The question of the effectiveness is connected with the question what is understood as an effect. In principle, the effect of the intervention is understood on the basis of the occlusion or dental health, what disregards further functions of oral health. The generalization to oral health is therefore a necessary consideration in science now. If one appreciates this further development, then there is no one single randomised study available which examines the long-term effect of the orthodontic intervention or for the effects on the oral health. The question, whether the application of a fixed appliance in an orthodontic treatment causes a long-term improvement in oral health, cannot be answered at the present time. The scientific status is the definition of oral health at present. Also the question, whether in the long run the dental health can be improved by fixed appliances cannot be answered with a quality usually achieved by evidence-based medicine. Whether correction of a dental malposition is an effective prerequisite for the preservation of the natural teeth, cannot be answered. There is no generalizing study with sufficient scientific background for Europe or Germany to this topic. The risk for caries cannot be quantified. Caries is identified as a central topic in general but due to numerous factors influencing the risk it is not quantified. The question of the indications is completely open from the scientific literature. For the question of the therapy need or therapy priority some indexes were developed, which lead to a quantification. These indices however are fundamentally criticised by recent research in their meaning and the empirical relevance. There is an impression that there exists a big gap between the practical application

  1. Oral health with fixed appliances orthodontics

    Science.gov (United States)

    Frank, Wilhelm; Pfaller, Karin; Konta, Brigitte

    2008-01-01

    Orthodontic treatment represents an important fraction in dental interventions. According to other medical methods the question for scientific evidence for the effectiveness of these treatments arises. The question of the effectiveness is connected with the question what is understood as an effect. In principle, the effect of the intervention is understood on the basis of the occlusion or dental health, what disregards further functions of oral health. The generalization to oral health is therefore a necessary consideration in science now. If one appreciates this further development, then there is no one single randomised study available which examines the long-term effect of the orthodontic intervention or for the effects on the oral health. The question, whether the application of a fixed appliance in an orthodontic treatment causes a long-term improvement in oral health, cannot be answered at the present time. The scientific status is the definition of oral health at present. Also the question, whether in the long run the dental health can be improved by fixed appliances cannot be answered with a quality usually achieved by evidence-based medicine. Whether correction of a dental malposition is an effective prerequisite for the preservation of the natural teeth, cannot be answered. There is no generalizing study with sufficient scientific background for Europe or Germany to this topic. The risk for caries cannot be quantified. Caries is identified as a central topic in general but due to numerous factors influencing the risk it is not quantified. The question of the indications is completely open from the scientific literature. For the question of the therapy need or therapy priority some indexes were developed, which lead to a quantification. These indices however are fundamentally criticised by recent research in their meaning and the empirical relevance. There is an impression that there exists a big gap between the practical application and the scientific

  2. ANALISIS TRANSIEN PADA FIXED BED NUCLEAR REACTOR

    Directory of Open Access Journals (Sweden)

    M. Rizaal

    2015-03-01

    Full Text Available Desain teras Fixed Bed Nuclear Reactor (FBNR yang modular memungkinkan pengendalian daya dapat dilakukan dengan mengatur ketinggian suspended core dan laju aliran massa pendingin. Tujuan penelitian ini adalah mempelajari perubahan daya termal teras sebagai akibat perubahan laju aliran massa pendingin yang masuk ke teras reaktor dan perubahan ketinggian suspended core serta mempelajari karakteristik keselamatan melekat yang dimiliki FBNR saat terjadi kegagalan pelepasan kalor (loss of heat sink. Keadaan neutronik teras dimodelkan pada kondisi tunak dengan menggunakan paket program Standard Reactor Analysis Code (SRAC untuk memperoleh data fluks neutron, konstanta grup, fraksi neutron kasip, konstanta peluruhan prekursor neutron kasip, dan beberapa parameter teras penting lainnya. Selanjutnya data tersebut digunakan pada perhitungan transien sebagai syarat awal. Analisis transien dilakukan pada tiga kondisi, yaitu saat terjadi penurunan laju aliran massa pendingin, saat terjadi penurunan ketinggian suspended core, dan saat terjadi kegagalan sistem pelepasan kalor. Hasil yang diperoleh dari penelitian ini menunjukkan bahwa penurunan laju aliran massa pendingin sebesar 50%, dari kondisi normal, menyebabkan daya termal teras turun 28% dibanding daya sebelumnya. Penurunan ketinggian suspended core sebesar 30% dari ketinggian normal menyebabkan daya termal teras turun 17% dibanding daya sebelumnya. Sementara untuk kondisi kegagalan sistem pelepasan kalor, daya termal teras mengalami penurunan sebesar 76%. Dengan demikian, pengendalian daya pada FBNR dapat dilakukan dengan mengatur laju aliran massa pendingin dan ketinggian suspended core, serta keselamatan melekat yang handal pada kondisi kegagalan sistem pelepasan kalor. Kata kunci: FBNR, transien, daya, laju aliran massa, suspended core Modular in design enables Fixed Bed Nuclear Reactor (FBNR power controlled by the adjustment of suspended core and coolant flow rate. The main purposes of this paper

  3. Simulations at fixed topology: fixed topology versus ordinary finite volume corrections

    OpenAIRE

    2015-01-01

    Lattice QCD simulations tend to get stuck in a single topological sector at fine lattice spacing, or when using chirally symmetric quarks. In such cases computed observables differ from their full QCD counterparts by finite volume corrections, which need to be understood on a quantitative level. We extend a known relation from the literature between hadron masses at fixed and at unfixed topology by incorporating in addition to topological finite volume effects, also ordinary finite volume eff...

  4. Breakdown localization in the fixed gap system

    CERN Document Server

    Rajamaki, Robin; Wuensch, Walter

    2014-01-01

    Accurate localization of breakdowns in vacuum could help shed light on breakdown related processes that are not yet fully understood. At the DC spark lab at CERN, an instrument called the Fixed Gap System (FGS) has been developed partially for this purpose. Among other things, the FGS has four built-in antennas, which are intended for breakdown localization. The capability of this aspect of the FGS was explored in this report. Specifically, the feasibility of using a method similar to that which is used in cavity Beam Position Monitors (BPMs) was investigated. The usable frequency range of the current experimental setup was also studied. Firstly, a modal analysis of the inner geometry of the FGS was done in HFSS. This showed that the two first modes to be expected in the spark gap quite differ from those of the ideal pillbox – both in field pattern and in frequency ( 4 and 6 GHz vs. 0.2 and 3 GHz). Secondly, S-parameters of the system were measured. These showed that the coupling between antennas is weak...

  5. Pain control during fixed orthodontic appliance therapy.

    Science.gov (United States)

    Polat, Omur; Karaman, Ali Ihya

    2005-03-01

    The control of pain during orthodontic treatment is of great interest to both clinicians and patients. However, there has been limited research into the control of this pain, and there is no standard of care for controlling this discomfort. This prospective study determines the pain sequelae in fixed orthodontic treatment and evaluates comparatively the analgesic effects of nonsteroidal anti-inflammatory drugs for the control of this pain. One hundred and fifty orthodontic patients who were to have teeth bonded in at least one arch were randomly assigned to one of six groups: (1) placebo/placebo, (2) ibuprofen/ibuprofen, (3) flurbiprofen/flurbiprofen, (4) acetaminophen/acetaminophen, (5) naproxen sodium/naproxen sodium, and (6) aspirin/aspirin. The pain evaluations were made during chewing, biting, fitting the front teeth, and fitting the back teeth using a 100-mm visual analogue scale (VAS) for seven days. All the analgesics succeeded in decreasing the pain levels compared with the placebo group. However, naproxen sodium and aspirin groups showed the lowest pain values, and the acetaminophen group showed VAS results similar to those of the two analgesics.

  6. Characteristic Formulae for Relations with Nested Fixed Points

    Directory of Open Access Journals (Sweden)

    Luca Aceto

    2012-02-01

    Full Text Available A general framework for the connection between characteristic formulae and behavioral semantics is described in [2]. This approach does not suitably cover semantics defined by nested fixed points, such as the n-nested simulation semantics for n greater than 2. In this study we address this deficiency and give a description of nested fixed points that extends the approach for single fixed points in an intuitive and comprehensive way.

  7. Capturing the Correlations of Fixed-income Instruments

    OpenAIRE

    John M. Mulvey; Stavros A. Zenios (Editor of the Focused Issue)

    1994-01-01

    This paper develops a framework for managing portfolios of fixed income instruments based on traditional principles from the equities market, i.e., based on diversification. It shows, through an analysis of the high-yield bond market over the period 1987 to 1991, that fixed-income prices could be highly correlated. These correlations can be quantified and integrated, in a systematic way, in an asset/liability management framework. For vanishing fixed income securities, however, we cannot reso...

  8. Enriching vermicompost by nitrogen fixing and phosphate solubilizing bacteria.

    Science.gov (United States)

    Kumar, V; Singh, K P

    2001-01-01

    The effect of inoculation of vermicompost with nitrogen-fixing Azotobacter chroococcum strains, Azospirillum lipoferum and the phosphate solubilizing Pseudomonas striata on N and P contents of the vermicompost was assessed. Inoculation of N2 fixing bacteria into vermicompost increased contents of N and P. Enriching vermicompost with rock phosphate improved significantly the available P when inoculated with P. striata. During the incubation period, the inoculated bacterial strains proliferated rapidly, fixed N and solubilized added and native phosphate.

  9. Existence of Multiple Fixed Points for Nonlinear Operators and Applications

    Institute of Scientific and Technical Information of China (English)

    Jing Xian SUN; Ke Mei ZHANG

    2008-01-01

    In this paper,by the fixed point index theory,the number of fixed points for sublinear and asymptotically linear operators via two coupled parallel sub-super solutions is studied.Under suitable conditions,the existence of at least nine or seven distinct fixed points for sublinear and asymptotically linear operators is proved.Finally,the theoretical results are applied to a nonlinear system of Hammerstein integral equations.

  10. Talking about increasing efficiency for reasonable choosing the cutter and cutting parameters%浅谈如何合理选择刀具及切削参数以提高工效

    Institute of Scientific and Technical Information of China (English)

    刘军

    2012-01-01

    Under the permise of quality assurance of the machine parts processing, how to maximize the rate of metal removal by using of the numerical control mechine is the crucial factor in increasing the processing ef-feciency. The article focused on the problems of how to choose the cutter and cutting parameters to maximize the rate of metal removal by using of numerical control machine to process those difficult processing materials such as antihydrogen steel and molybdenum.%在同样满足零件加工品质的前提下,数控机床提高加工效率的关键在于如何使金属切除率达到最大.讨论了在抗氢钢、钼等难加工材料加工中,针对特定的数控车床,通过合理地选择刀具及切削参数来确定最大金属切除率的问题.

  11. 3500m3/h绞吸挖泥船甲板机舱振动分析与优化%Analysis and Optimization of Deck Cabin Vibration in 3 500 m3/h Cutter Suction Dredger

    Institute of Scientific and Technical Information of China (English)

    王炜

    2015-01-01

    针对3500 m3/h绞吸式挖泥船的甲板机舱异常振动问题,建立机舱结构有限元模型,进行振动模态分析,发现甲板下支柱与柴油机工作频率耦合引起的共振是导致甲板机舱异常振动的主要原因,进行甲板机舱结构和立柱位置的优化,检测表明,优化后的结构有效避开了共振频率,振动速度峰值和加速度大幅下降,优化效果良好。%In view of abnormal vibration on deck engine room of 3 500 m3/h cutter suction dredger, the FE structural model of the engine room is established.Via the analysis of mode of vibration, resonance coupling of working frequency of the diesel en-gine with the pillar under deck is the primary cause for abnormal vibration of deck engine room.So the location of pillars is rede-signed to avoid the resonant frequency.The test results verify that the peaks of vibration acceleration and velocity are sharply de-creased;the effects of optimization are satisfactory.

  12. 某型号收割机割刀机构及其传动部件惯性力平衡的研究%Research on Inertia Force Equilibrium of Cutter and Transmission Parts in a Type of Harvester

    Institute of Scientific and Technical Information of China (English)

    许汝炜; 王俊田

    2015-01-01

    针对某型号收割机割刀执行及传动机构的实际工作中的性能需求,在完成机构惯性力最小的基础上,考虑实际工作情况权衡各方面因素的部分平衡的最优方案,最终得出了最优的设计参数,其研究方案可为类似杆机构惯性力平衡问题提供有益的参考。%Aiming at the performance requirements of the cutter execution and transmission mechanism in a type of harvester at the actual working process, and on minimum inertia force of the complete organization, the optimal design parameters are con-cluded with consideration of the actual working condition and the optimal solution of partial equilibrium on the various aspects, and such research programme could be beneficial reference for the similar equilibrium problems of inertia force.

  13. Fixed-node and fixed-phase approximations and their relationship to variable spins in quantum Monte Carlo

    CERN Document Server

    Melton, Cody A

    2016-01-01

    We compare the fixed-phase approximation with the better known, but closely related fixed-node approximation on several testing examples. We found that both approximations behave very similarly with the fixed-phase results being very close to the fixed-node method whenever nodes/phase were of high and comparable accuracy. The fixed-phase exhibited larger biases when the trial wave functions errors in the nodes/phase were intentionally driven to unrealistically large values. We also present a formalism that enables to describe wave functions with the full antisymmetry in spin-spatial degrees of freedom using our recently developed method for systems with spins as fully quantum variables. This opens new possibilities for simulations of fermionic systems in the fixed-phase approximation formalism.

  14. Auxins upregulate nif and fix genes.

    Science.gov (United States)

    Bianco, Carmen; Defez, Roberto

    2010-10-01

    In a recent publication we analyzed the global effects triggered by IAA overproduction in S. meliloti RD64 under free-living conditions by comparing the gene expression pattern of wild type 1021 with that of RD64 and 1021 treated with IAA and other four chemically or functionally related molecules. Among the genes differentially expressed in RD64 and IAA-treated 1021 cells we found two genes of pho operon, phoT and phoC. Based on this finding we examined the mechanisms for mineral P solubilization in RD64 and the potential ability of this strain to improve Medicago growth under P-starved conditions. Here, we further analyze the expression profiles obtained in microarray analysis and evaluate the specificity and the extent of overlap between all treatments. Venn diagrams indicated that IAA- and 2,4-D-regulated genes were closely related. Furthermore, most differentially expressed genes from pSymA were induced in 1021 cells treated with 2,4-D, ICA, IND and Trp as compared to the untreated 1021 cells. RT-PCR analysis was employed to analyze the differential expression patterns of nitrogen fixation genes under free-living and symbiotic conditions. Under symbiotic condition, the relative expression levels of nif and fix genes were significantly induced in Mt- RD64 plants and in Mt-1021 plants treated with IAA and 2,4-D whereas they were unchanged or repressed in Mt-1021 plants treated with the other selected compounds when compared to the untreated Mt-1021 plants.

  15. Aeroelasticity Benchmark Assessment: Subsonic Fixed Wing Program

    Science.gov (United States)

    Florance, Jennifer P.; Chwalowski, Pawel; Wieseman, Carol D.

    2010-01-01

    Aeroelasticity Branch will examine other experimental efforts within the Subsonic Fixed Wing (SFW) program (such as testing of the NASA Common Research Model (CRM)) and other NASA programs and assess aeroelasticity issues and research topics.

  16. GRINDING OF SHAPED TOOLS ON CNC TOOL GRINDER

    Directory of Open Access Journals (Sweden)

    Ján Kráľ

    2013-03-01

    Full Text Available Worm gears are special gears consisting of a worm wheel and a worm. Worm gears can be produced in different ways, depending on the size of the transmission, the number of courses, the pitch angle of worm profile, the number of units produced, the purpose of application, etc. As cylindrical worm gears we consider the cylindrical worms with globoid gears, globoid worm with globoid worm gear and globoid worm with cylindrical worm gearing. This paper deals with the evolvent worm whose curve of the tooth side in the front plane is evolvent. The production of worm with an optimal profile for optimal meshing conditions is an increasingly frequent focus of worm gear manufacturers. The problem of designing the tool cutting edge can be divided into several steps. This article deals with the problems of optimum design of a tool shape for the production of worms; and the problems of calculating the coordinates of the transition cutting edge shape, and thus the path of grinding wheel for sharpening the tool cutting edge shape are solved. By grinding tool of grinding machine we can complete the worm shape and also sharpen the cutting edges of tools for production of worm surface. The problems of calculation of the coordinates are solved with regard to the functioning of the KON 250 CNC grinding machine logic.

  17. Cookie-cutter halos: the remarkable constancy of the stellar mass function of satellite galaxies at 0.2

    CERN Document Server

    Tal, Tomer; Muzzin, Adam; Marchesini, Danilo; Stefanon, Mauro

    2014-01-01

    We present an observational study of the stellar mass function of satellite galaxies around central galaxies at 0.2fixed central mass is at most weakly dependent on redshift. We conclude that the average mass distribution of galaxies in groups is remarkably universal even out to z=1.2 and that it can be uniquely characterized by the group central galaxy mass. This further suggests that as central galaxies grow in stellar mass, they do so in tandem with the mass growth of their satellites. Finally, we classify all galaxies as either star forming or quiescent, and derive the mass functions of each subpopulation separately. We find that the mass distribution of both star for...

  18. Human cell lines: A promising alternative for recombinant FIX production.

    Science.gov (United States)

    de Sousa Bomfim, Aline; Cristina Corrêa de Freitas, Marcela; Picanço-Castro, Virgínia; de Abreu Soares Neto, Mário; Swiech, Kamilla; Tadeu Covas, Dimas; Maria de Sousa Russo, Elisa

    2016-05-01

    Factor IX (FIX) is a vitamin K-dependent protein, and it has become a valuable pharmaceutical in the Hemophilia B treatment. We evaluated the potential of recombinant human FIX (rhFIX) expression in 293T and SK-Hep-1 human cell lines. SK-Hep-1-FIX cells produced higher levels of biologically active protein. The growth profile of 293T-FIX cells was not influenced by lentiviral integration number into the cellular genome. SK-Hep-1-FIX cells showed a significantly lower growth rate than SK-Hep-1 cells. γ-carboxylation process is significant to FIX biological activity, thus we performed a expression analysis of genes involved in this process. The 293T gene expression suggests that this cell line could efficiently carboxylate FIX, however only 28% of the total secreted protein is active. SK-Hep-1 cells did not express high amounts of VKORC1 and carboxylase, but this cell line secreted large amounts of active protein. Enrichment of culture medium with Ca(+2) and Mg(+2) ions did not affect positively rhFIX expression in SK-Hep-1 cells. In 293T cells, the addition of 0.5 mM Ca(+2) and 1 mM Mg(+2) resulted in higher rhFIX concentration. SK-Hep-1 cell line proved to be very effective in rhFIX production, and it can be used as a novel biotechnological platform for the production of recombinant proteins.

  19. Nitrogen-fixing aerobic bacteria have higher genomic GC content than non-fixing species within the same genus

    OpenAIRE

    McEwan, Catriona E.; Gatherer, Derek; McEwan, Neil R.

    1998-01-01

    The genomic GC contents of both nitrogen-fixing and non-fixing members of eight genera of bacteria are investigated. Analysis by t-tests showed that in the two aerobic genera investigated (Aquaspirillum and Vibrio) there is a significantly higher GC content in the nitrogen-fixing members of the genus than in those unable to Fix nitrogen, whilst in anaerobic genera there is either no GC bias, or in the case of two genera (Rhodospirillum and Clostridium) there is a significantly higher GC conte...

  20. Normal eyeblink classical conditioning in patients with fixed dystonia

    NARCIS (Netherlands)

    Janssen, S.; Veugen, L.C.; Hoffland, B.S.; Kassavetis, P.; Rooijen, D.E. van; Stegeman, D.F.; Edwards, Mark J.; Hilten, J.J. van; Warrenburg, B.P.C. van de

    2014-01-01

    Fixed dystonia without evidence of basal ganglia lesions or neurodegeneration typically affects young women following minor peripheral trauma. We use eyeblink classical conditioning (EBCC) to study whether cerebellar functioning is abnormal in patients with fixed dystonia, since this is part of the

  1. 40 CFR 63.1042 - Standards-Separator fixed roof.

    Science.gov (United States)

    2010-07-01

    ...) National Emission Standards for Oil-Water Separators and Organic-Water Separators § 63.1042 Standards... controlling air emissions from an oil-water separator or organic-water separator using a fixed roof. (b) The... interface of the roof edge and the separator wall. (3) Each opening in the fixed roof shall be equipped...

  2. FIXED POINT RESULTS ON METRIC-TYPE SPACES

    Institute of Scientific and Technical Information of China (English)

    Monica COSENTINO; Peyman SALIMI; Pasquale VETRO

    2014-01-01

    In this paper we obtain fixed point and common fixed point theorems for self-mappings defined on a metric-type space, an ordered metric-type space or a normal cone metric space. Moreover, some examples and an application to integral equations are given to illustrate the usability of the obtained results.

  3. Caristi Fixed Point Theorem in Metric Spaces with a Graph

    Directory of Open Access Journals (Sweden)

    M. R. Alfuraidan

    2014-01-01

    Full Text Available We discuss Caristi’s fixed point theorem for mappings defined on a metric space endowed with a graph. This work should be seen as a generalization of the classical Caristi’s fixed point theorem. It extends some recent works on the extension of Banach contraction principle to metric spaces with graph.

  4. 12 CFR 619.9180 - Fixed interest spread.

    Science.gov (United States)

    2010-01-01

    ... 12 Banks and Banking 6 2010-01-01 2010-01-01 false Fixed interest spread. 619.9180 Section 619.9180 Banks and Banking FARM CREDIT ADMINISTRATION FARM CREDIT SYSTEM DEFINITIONS § 619.9180 Fixed interest spread. A percentage to be added to the cost of money to the bank or association as the means...

  5. 12 CFR 619.9170 - Fixed interest rate.

    Science.gov (United States)

    2010-01-01

    ... 12 Banks and Banking 6 2010-01-01 2010-01-01 false Fixed interest rate. 619.9170 Section 619.9170 Banks and Banking FARM CREDIT ADMINISTRATION FARM CREDIT SYSTEM DEFINITIONS § 619.9170 Fixed interest rate. The rate of interest specified in the note or loan document which will prevail as the...

  6. Scale-up of fixed-bed chemical looping combustion

    NARCIS (Netherlands)

    Kimball, E.; Geerdink, P.; Goetheer, E.L.V.

    2011-01-01

    Fixed-bed chemical looping combustion is currently being studied experimentally with the optimization of systems up to 1 kW. One of the key advantages for using the fixed-bed configuration over fluidized-beds is the flexibility in operating parameters that allows for application of CLC not only to

  7. Fixed-Parameter Tractability of Disjunction-Free Default Reasoning

    Institute of Scientific and Technical Information of China (English)

    ZHAO XiShun(赵希顺); DING DeCheng(丁德成)

    2003-01-01

    In this paper, the parameter which is the source of the complexity of disjunctionfree default reasoning is determined. It is shown that when the value of this parameter is fixed, the disjunction-free default reasoning can be solved in time bounded by a polynomial whose degree does not depend on the parameter. Consequently, disjunction-free default reasoning is fixed parameter tractable.

  8. 29 CFR 1910.24 - Fixed industrial stairs.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 5 2010-07-01 2010-07-01 false Fixed industrial stairs. 1910.24 Section 1910.24 Labor... OCCUPATIONAL SAFETY AND HEALTH STANDARDS Walking-Working Surfaces § 1910.24 Fixed industrial stairs. (a) Application of requirements. This section contains specifications for the safe design and construction of...

  9. Floating-to-Fixed-Point Conversion for Digital Signal Processors

    Directory of Open Access Journals (Sweden)

    Menard Daniel

    2006-01-01

    Full Text Available Digital signal processing applications are specified with floating-point data types but they are usually implemented in embedded systems with fixed-point arithmetic to minimise cost and power consumption. Thus, methodologies which establish automatically the fixed-point specification are required to reduce the application time-to-market. In this paper, a new methodology for the floating-to-fixed point conversion is proposed for software implementations. The aim of our approach is to determine the fixed-point specification which minimises the code execution time for a given accuracy constraint. Compared to previous methodologies, our approach takes into account the DSP architecture to optimise the fixed-point formats and the floating-to-fixed-point conversion process is coupled with the code generation process. The fixed-point data types and the position of the scaling operations are optimised to reduce the code execution time. To evaluate the fixed-point computation accuracy, an analytical approach is used to reduce the optimisation time compared to the existing methods based on simulation. The methodology stages are described and several experiment results are presented to underline the efficiency of this approach.

  10. The importance of fixed costs in animal health systems.

    Science.gov (United States)

    Tisdell, C A; Adamson, D

    2017-04-01

    In this paper, the authors detail the structure and optimal management of health systems as influenced by the presence and level of fixed costs. Unlike variable costs, fixed costs cannot be altered, and are thus independent of the level of veterinary activity in the short run. Their importance is illustrated by using both single-period and multi-period models. It is shown that multi-stage veterinary decision-making can often be envisaged as a sequence of fixed-cost problems. In general, it becomes clear that, the higher the fixed costs, the greater the net benefit of veterinary activity must be, if such activity is to be economic. The authors also assess the extent to which it pays to reduce fixed costs and to try to compensate for this by increasing variable costs. Fixed costs have major implications for the industrial structure of the animal health products industry and for the structure of the private veterinary services industry. In the former, they favour market concentration and specialisation in the supply of products. In the latter, they foster increased specialisation. While cooperation by individual farmers may help to reduce their individual fixed costs, the organisational difficulties and costs involved in achieving this cooperation can be formidable. In such cases, the only solution is government provision of veterinary services. Moreover, international cooperation may be called for. Fixed costs also influence the nature of the provision of veterinary education.

  11. Fixed export costs and multi-product firms

    NARCIS (Netherlands)

    Creusen, H.; Smeets, R.

    2011-01-01

    This paper has two aims. First, we uncover some salient components of fixed export costs, which play a crucial role in recent heterogeneous firms models of international trade. Second, we investigate whether the importance of these fixed export costs varies with the size of a firms export product

  12. Synthesis and characterization of zwitterionic carbon dioxide fixing reagents

    DEFF Research Database (Denmark)

    Mikkelsen, Mette; Jørgensen, Mikkel; Krebs, Frederik C

    2010-01-01

    The synthesis of three amine-based carbon dioxide fixing reagents is presented. The reagents were designed so that they would be able to bind CO2 reversibly through the formation of the well known carbamates that was stabilized through forming a zwitterion. CO2 fixing experiments were performed...

  13. Some fixed point results for dualistic rational contractions

    Directory of Open Access Journals (Sweden)

    Muhammad Nazam

    2016-10-01

    Full Text Available In this paper, we introduce a new contraction called dualistic contraction of rational type and obtain some fixed point results. These results generalize various comparable results appeared in the literature. We provide an example to show the superiority of our results over corresponding fixed point results proved in metric spaces.

  14. Non Linear Gauge Fixing for FeynArts

    CERN Document Server

    Gajdosik, Thomas

    2007-01-01

    We review the non-linear gauge-fixing for the Standard Model, proposed by F. Boudjema and E. Chopin, and present our implementation of this non-linear gauge-fixing to the Standard Model and to the minimal supersymmetric Standard Model in FeynArts.

  15. 29 CFR 1910.160 - Fixed extinguishing systems, general.

    Science.gov (United States)

    2010-07-01

    ... all fixed extinguishing systems installed to meet a particular OSHA standard except for automatic sprinkler systems which are covered by § 1910.159. (2) This section also applies to fixed systems not... discharge area prior to system discharge. (4) The employer shall provide automatic actuation of...

  16. FIXED POINTS THEOREMS IN MULTI-METRIC SPACES

    Directory of Open Access Journals (Sweden)

    Laurentiu I. Calmutchi

    2011-07-01

    Full Text Available The aim of the present article is to give some general methods inthe fixed point theory for mappings of general topological spaces. Using the notions of the multi-metric space and of the E-metric space, we proved the analogous of several classical theorems: Banach fixed point principle, Theorems of Edelstein, Meyers, Janos etc.

  17. Aspirin induced fixed drug eruptions: a case report

    Directory of Open Access Journals (Sweden)

    Rama R. Bhosale

    2013-04-01

    Full Text Available Fixed drug eruptions are common cutaneous adverse drug reactions, commonly caused by anticonvulsants, antibiotics and analgesics. Here, we report a case of a 27-year-old male of fixed drug eruptions due to Aspirin which was used in treatment of headache. [Int J Basic Clin Pharmacol 2013; 2(2.000: 220-221

  18. Families of Fixed Degree Graphs for Processor Interconnection

    DEFF Research Database (Denmark)

    Jerrum, Mark; Skyum, Sven

    1984-01-01

    A construction is presented which, given a fixed undirected graph of low degree and small average path length, yields an infinite sequence of low diameter graphs of increasing order and fixed degree. As examples of the construction, infinite sequences of low diameter graphs are presented with deg...

  19. 46 CFR 169.565 - Fixed carbon dioxide system.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Fixed carbon dioxide system. 169.565 Section 169.565... Lifesaving and Firefighting Equipment Firefighting Equipment § 169.565 Fixed carbon dioxide system. (a) The number of pounds of carbon dioxide required for each space protected must be equal to the gross volume...

  20. Fixed points and infrared completion of quantum gravity

    CERN Document Server

    Christiansen, Nicolai; Pawlowski, Jan M; Rodigast, Andreas

    2012-01-01

    The phase diagram of four-dimensional Einstein-Hilbert gravity is studied using Wilson's renormalization group. Smooth trajectories connecting the ultraviolet fixed point at short distances with attractive infrared fixed points at long distances are derived from the non-perturbative graviton propagator. Implications for the asymptotic safety conjecture and further results are discussed.

  1. STABILITY OF A PARABOLIC FIXED POINT OF REVERSIBLE MAPPINGS

    Institute of Scientific and Technical Information of China (English)

    LIUBIN; YOUJIANGONG

    1994-01-01

    KAM theorem of reversible system is used to provide a sufficient condition which guarantees the stability of a parabolic fixed point of reversible mappings, The main idea is to discuss when the parabolic fixed point is surrounded by closed invariant carves and thus exhibits stable behaviour.

  2. Fixed Points on Abstract Structures without the Equality Test

    DEFF Research Database (Denmark)

    Korovina, Margarita

    2002-01-01

    The aim of this talk is to present a study of definability properties of fixed points of effective operators on abstract structures without the equality test. The question of definability of fixed points of -operators on abstract structures with equality was first studied by Gandy, Barwise, Mosch...

  3. Brouwer's ε-fixed point from Sperner's lemma

    NARCIS (Netherlands)

    Dalen, D. van

    2009-01-01

    It is by now common knowledge that Brouwer gave mathematics in 1911 a miraculous tool, the fixed point theorem, and that later in life, he disavowed it. It usually came as a shock when he replied to the question “is the fixed point theorem correct ?” with a point blank “no”. This rhetoric exchange d

  4. Nonlinear Contractive Conditions for Coupled Cone Fixed Point Theorems

    Directory of Open Access Journals (Sweden)

    Du Wei-Shih

    2010-01-01

    Full Text Available We establish some new coupled fixed point theorems for various types of nonlinear contractive maps in the setting of quasiordered cone metric spaces which not only obtain several coupled fixed point theorems announced by many authors but also generalize them under weaker assumptions.

  5. ON COLLECTIVELY FIXED POINT THEOREMS ON FC-SPACES

    Institute of Scientific and Technical Information of China (English)

    Yongjie Piao

    2010-01-01

    Based on a KKM type theorem on FC-space,some new fixed point theorems for Fan-Browder type are established,and then some collectively fixed point theorems for a family of Φ-maps defined on product space of FC-spaees are given.These results generalize and improve many corresponding results.

  6. Detection of Chlamydia in postmortal formalin-fixed tissue

    DEFF Research Database (Denmark)

    Lundemose, A G; Banner, Jytte; Birkelund, Svend;

    1989-01-01

    A procedure to detect Chlamydia in postmortal formalin-fixed tissue is described. Monoclonal antibodies against a genus specific chlamydia epitope were used in immunofluorescence to detect chlamydia inclusions in formalin-fixed tissue sections. Lung sections from chlamydia-infected mice were exam...

  7. Tariffs and Firm-Level Heterogeneous Fixed Export Costs

    DEFF Research Database (Denmark)

    Schröder, Philipp J.H.; Jørgensen, Jan Guldager

    2006-01-01

    This paper presents a two country intra-industry trade model with bilateral ad valorem tariffs and fixed export costs that are heterogeneous across firms. In this model not all firms will choose to export. We examine the effects of reciprocal changes in the tariff and the fixed export barrier...... on the number of firms, firm profits, tariff revenue and consumer welfare. We show that both types of trade barriers reduce (increase) the number of exporting (pure domestic) firms. However, the sum of available home and foreign varieties may actually increase for small tariffs. Firm profits fall for both...... the tariff and the fixed export barrier. Tariff revenue falls for an increase in fixed exporting costs whereas we have a Laffer curve effect for the tariff. Finally, we establish that welfare falls with fixed export costs and large tariffs but increases for small tariffs, i.e. there exist a welfare...

  8. Infrared fixed points and fixed lines in the top-bottom-$\\tau$ sector in supersymmetric grand unification

    CERN Document Server

    Schrempp, Barbara

    1994-01-01

    The two-loop ``top-down'' renormalization group flow for the top, bottom and tau Yukawa couplings is explored in the framework of supersymmetric grand unification; reproduction of the physical bottom and tau masses is required. Instead of following the recent trend of implementing exact Yukawa coupling unification i) a search for infrared (IR) fixed lines and fixed points in the m(top)-tan(beta) plane is performed and ii) the extent to which these imply approximate Yukawa unification is determined. Two IR fixed lines, intersecting in an IR fixed point, are located. The more attractive fixed line has a branch of almost constant top mass, 168-180 GeV, close to the experimental value, for the large interval 2.5fixed point at m(top)= 170 GeV, tan(beta)=55 implements approximate top-bottom Yukawa unification at all scales. The fixed point and lines are distinct from the much quoted effective IR fixed point m(top)=O(200)GeV si...

  9. Fixed-time stability of dynamical systems and fixed-time synchronization of coupled discontinuous neural networks.

    Science.gov (United States)

    Hu, Cheng; Yu, Juan; Chen, Zhanheng; Jiang, Haijun; Huang, Tingwen

    2017-05-01

    In this paper, the fixed-time stability of dynamical systems and the fixed-time synchronization of coupled discontinuous neural networks are investigated under the framework of Filippov solution. Firstly, by means of reduction to absurdity, a theorem of fixed-time stability is established and a high-precision estimation of the settling-time is given. It is shown by theoretic proof that the estimation bound of the settling time given in this paper is less conservative and more accurate compared with the classical results. Besides, as an important application, the fixed-time synchronization of coupled neural networks with discontinuous activation functions is proposed. By designing a discontinuous control law and using the theory of differential inclusions, some new criteria are derived to ensure the fixed-time synchronization of the addressed coupled networks. Finally, two numerical examples are provided to show the effectiveness and validity of the theoretical results. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. The asymptotic equivalence of fixed heat flux and fixed temperature thermal boundary conditions for rapidly rotating convection

    CERN Document Server

    Calkins, Michael A; Julien, Keith; Nieves, David; Driggs, Derek; Marti, Philippe

    2015-01-01

    The influence of fixed temperature and fixed heat flux thermal boundary conditions on rapidly rotating convection in the plane layer geometry is investigated for the case of stress-free mechanical boundary conditions. It is shown that whereas the leading order system satisfies fixed temperature boundary conditions implicitly, a double boundary layer structure is necessary to satisfy the fixed heat flux thermal boundary conditions. The boundary layers consist of a classical Ekman layer adjacent to the solid boundaries that adjust viscous stresses to zero, and a layer in thermal wind balance just outside the Ekman layers adjusts the temperature such that the fixed heat flux thermal boundary conditions are satisfied. The influence of these boundary layers on the interior geostrophically balanced convection is shown to be asymptotically weak, however. Upon defining a simple rescaling of the thermal variables, the leading order reduced system of governing equations are therefore equivalent for both boundary condit...

  11. Auctionable fixed transmission rights for congestion management

    Science.gov (United States)

    Alomoush, Muwaffaq Irsheid

    the transaction by the ISO, take a decision to expand the existing system, or retain the original structure of the system. Also, the thesis investigates the impact of wheeling transactions on congestion management, where we present a generalized mathematical model for the Fixed Transmission Right (FTR) auction. The auction guarantees FTR availability to all participants on a non-discriminatory basis, in which system users are permitted to buy, sell and trade FTRs through an auction. When FTRs are utilized with LMPs, they increase the efficient use of the transmission system and let a transmission customer gain advantageous features such as acquiring a mechanism to offset the extra cost due to congestion charges, providing financial and operational certainty and making system users pay for the actual use of the congested paths. The thesis also highlighted FTR trading in secondary markets to self-arrange access across different paths, create long-term transmission rights and provide more commercial certainty.

  12. Safe switching from a pdFIX (Immunine®) to a rFIX (Bax326).

    Science.gov (United States)

    Solano Trujillo, M H; Stasyshyn, O; Rusen, L; Serban, M; Lamas, J L; Perina, F G; Urasinski, T; Oh, M; Knowlton, W B; Valenta-Singer, B; Pavlova, B G; Abbuehl, B

    2014-09-01

    The ability to switch between coagulation factors safely is of common interest to haemophilia patients and treating physicians. This is the first formal prospective comparative evaluation of safety, efficacy and incremental recovery of a plasma-derived FIX (pdFIX) and a recombinant FIX (rFIX) in the same haemophilia B patients following a switch from pdFIX Immunine® to a recently developed rFIX Bax326 product. Patients (aged <65 years) who completed a pretreatment study which prospectively documented the exposure to Immunine® and monitored FIX inhibitors while receiving prophylactic treatment were transitioned into pivotal (patients aged 12-65 years) and paediatric (patients aged <12 years) clinical studies investigating prophylaxis and treatment of bleeding episodes with Bax326. None of the 44 patients developed inhibitory or specific binding anti-FIX antibodies during the course of the studies. A total of 38 unrelated adverse events (AEs) were occurred in 20/44 (45.5%) subjects during the Immunine® study. Following a switch to Bax326, 51 AEs were reported in 25/44 (56.8%) subjects. The incidence of AEs related to Bax326 treatment (two episodes of dysgeusia in one patient) was low (2.3%); there were no serious adverse reactions. The comparison between Immunine® and Bax326 demonstrated analogous haemostatic characteristics and annualized bleeding rates. Overall, there is direct evidence indicating a safe and clinically effective transition from a pdFIX (Immunine®) to a newly developed rFIX (Bax326(1) ) for prophylaxis and treatment of bleeding in previously treated patients of all age cohorts with severe or moderately severe haemophilia B.

  13. A Method for Determining Available Fixed Ammonium in Soils

    Institute of Scientific and Technical Information of China (English)

    CHENGLI-LI; WENQI-XIAO; 等

    1994-01-01

    Dynamics of fixed NH4+ in NH4+-treated soils incubated with glucose at 37±2°C during the course of incubation and factors affecting it were studied.Results showed content of fixed NH4+ in soil reached a minimum on day 7 after incubation and then increased gradually regardless of the amount of glucose added and the kind of soil tested.Howerver,the amount of fixed NH4+ released from the soil at the given time varied with both the amount of glucose added and the kind of soil examined.In cases glucose was added at a rate of 10.0g C/kg soil,the amount of fixed NH4+ retained in soil after 7 days of incubation was almost identical to that found by neubauer test,Addition of K+ depressed the release of fixed NH4+ significantly,Based on the results obtained a method for determining the content of avaiable fixed NH4+ in soils was proposed and the amonut of N as available fixed NH4+ in two soils measured by this method on an area rpofile-depth basis was presented.

  14. Internal audit of costs on fixed assets repair

    Directory of Open Access Journals (Sweden)

    M.Yu. Samchyk

    2016-12-01

    Full Text Available The article focuses on the approaches to the process and methods of expenditure audit on repair and modernization of fixed assets and the author considers that there is no single approach to understanding the issue. The author improves the organizational and methodological support of internal audit of expenditures on the fixed assets repair and modernization that forms the accurate information for management repair and modernization of fixed assets. The paper specifies the goals and objectives of internal expenditures on repair and modernization of fixed assets, depending on the sources of such facilities to the company, allowing the author to determine the documentary control methods to be applied by an auditor to perform each task. The article determines the areas of risk components of internal control that can lead to ineffective implementation of authority by officials of an enterprise in the process of fixed assets repair, which can cause inefficient use of resources and, consequently, decrease in the efficiency of the work of fixed assets repair and modernization. The author proposes the list of auditor’s questions to assess the internal control system in the repair of fixed assets and these questions will help identify the significant drawbacks of control means.

  15. Organizadores e cortadores de comprimidos: riscos e restrições ao uso Organizadores y cortadores de comprimidos: riesgos y restricciones del uso Pill organizers and pill cutters: risks and limitations

    Directory of Open Access Journals (Sweden)

    Caroline Ribeiro de Borja-Oliveira

    2013-02-01

    use of pill organizers and cutters are discussed and analyzed as a matter of public health. The use of the organizers for storing and carrying tablets and capsules exposes these medications to environmental factors from which their original packaging protected them, compromising their stability and safeness. Cutters also pose the additional risk of causing loss of efficacy, adverse reactions and overdose. On the other hand, the user carrying their own medication reflects the balance between autonomy and self-care, and splitting is sometimes required to comply with certain regimens. It can be concluded that healthcare professionals should observe and guide patients and caregivers in order to avoid risks.

  16. Is Renormalized Entanglement Entropy Stationary at RG Fixed Points?

    CERN Document Server

    Klebanov, Igor R; Pufu, Silviu S; Safdi, Benjamin R

    2012-01-01

    The renormalized entanglement entropy (REE) across a circle of radius R has been proposed as a c-function in Poincar\\'e invariant (2+1)-dimensional field theory. A proof has been presented of its monotonic behavior as a function of R, based on the strong subadditivity of entanglement entropy. However, this proof does not directly establish stationarity of REE at conformal fixed points of the renormalization group. In this note we study the REE for the free massive scalar field theory near the UV fixed point described by a massless scalar. Our numerical calculation indicates that the REE is not stationary at the UV fixed point.

  17. PDF fit in the fixed-flavour-number scheme

    Energy Technology Data Exchange (ETDEWEB)

    Alekhin, S. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Institute for High Energy Physics, Moscow (Russian Federation); Bluemlein, J.; Moch, S. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany)

    2012-02-15

    We discuss the heavy-quark contribution to deep inelastic scattering in the scheme with n{sub f}=3;4;5 fixed flavors. Based on the recent ABM11 PDF analysis of world data for deep-inelastic scattering and fixed-target data for the Drell-Yan process with the running-mass definition for heavy quarks we show that fixed flavor number scheme is sufficient for describing the deep-inelastic-scattering data in the entire kinematic range. We compare with other PDF sets and comment on the implications for measuring the strong coupling constant {alpha}{sub s}(M{sub Z}).

  18. The Generalized Fixed-Charge Network Design Problem

    DEFF Research Database (Denmark)

    Thomadsen, Tommy; Stidsen, Thomas K.

    2007-01-01

    In this paper we present the generalized fixed-charge network design (GFCND) problem. The GFCND problem is an instance of the so-called generalized network design problems. In such problems, clusters instead of nodes have to be interconnected by a network. The network interconnecting the clusters...... is a fixed-charge network, and thus the GFCND problem generalizes the fixed-charge network design problem. The GFCND problem is related to the more general problem of designing hierarchical telecommunication networks. A mixed integer programming model is described and a branch-cut-and-price algorithm...

  19. Physical Observables from Lattice QCD at Fixed Topology

    CERN Document Server

    Brower, Richard C; Negele, J W; Wiese, U J

    2002-01-01

    Because present Monte Carol algorithms for lattice QCD may become trapped in a given topological charge sector when one approaches the continuum limit, it is important to understand the effect of calculating at fixed topology. In this work, we show that although the restriction to a fixed topological sector becomes irrelevant in the infinite volume limit, it gives rise to characteristic finite size effects due to contributions from all $\\theta$-vacua. We calculate these effects and show how to extract physical results from numerical data obtained at fixed topology.

  20. Constrained quantisation, gauge fixing and the Gribov ambiguity

    Energy Technology Data Exchange (ETDEWEB)

    McMullan, D. (Univ. of Plymouth (United Kingdom). School of Mathematics and Statistics)

    1994-03-01

    The role played by gauge fixing in the description of superselection sectors for a simple quantum mechanical system is analysed. By viewing this as a theory with constraints, it is shown that the possibility of having inequivalent gauge fixing conditions (Gribov's ambiguity) signals the existence of inequivalent reductions to a physical quantum theory, and hence superselection sectors. This point of view is contrasted with the more traditional one that identifies superselection sectors with inequivalent quantisations. It is argued that emphasising the role of gauge fixing (along with the Gribov problem) will allow for a more direct extension of these ideas to quantum field theory and, in particular, gauge theories. (orig.)