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Sample records for brake pads

  1. Thermal Characterisation of Brake Pads

    DEFF Research Database (Denmark)

    Ramousse, Séverine; Høj, Jakob Weiland; Sørensen, O. T.

    2001-01-01

    The chemical-physical decomposition processes that occur in a brake pad heated to 1000degreesC have been studied. This temperature can be reached when a brake pad is applied. Thermogravimetry and differential thermal analysis were used in combination with evolved gas analysis, and image analysis...... using a scanning electron microscope.A brake pad is essentially a mixture of iron, carbon and binder. Combined techniques have been used, because of chemical reaction overlap, to determine how and at what temperature the binder decomposes, the coal and graphite combust and the iron oxidises.This work...

  2. Marble Waste Using Produced of Automotive Brake Pad of Friction Coefficient Different Pad Brake Pads With Comprasion

    Directory of Open Access Journals (Sweden)

    Mustafa Timur

    2013-01-01

    Full Text Available Brake linings used in automotive disks are usually composed of various components. Expected properties from a brake lining are appropriate standard value of wear resist, friction coefficient. Brake lining extremely warms up during braking due to friction. The braking performance of brake lining changes and braking lining is subject to mechanical deformation due to excessive temperature. In this study, it is aimed to revaluate the waste of marble dust in marble processing in Turkey. For this purpose, marble wastes are grinded to produce marble dust. The brake lining, which has new formulation, is produced by using various additive materials. The friction performances of the brake pads produced were compared with those of other firms and the results were show in graphics. Therefore, the effect of marble dust on braking performance is investigated. It is observed that a favorable result in braking performance is obtained using of marble dust.

  3. Development of Asbestos - Free Brake Pad Using Bagasse

    Directory of Open Access Journals (Sweden)

    V. S. Aigbodion

    2010-03-01

    Full Text Available Development of asbestos-free brake pad using bagasse was investigated with a view to replace the use of asbestos whose dust is carcinogenic. The bagasse were sieve into sieve grades of 100, 150, 250, 350 and 710µm. the sieve bagasse was used in production of brake pad in ratio of 70%bagasse-30%resin using compression moulding. The properties examined are microstructure analysis, hardness, compressive strength, density, flame resistance, water and oil absorption. The microstructure reveals uniform distribution of resin in the bagasse. The results obtained showed that the finer the sieve size the better the properties. The results obtained in this work were compared with that of commercial brake pad (asbestos based and optimum formulation laboratory brake pad Palm Kernel Shell based (PKS, the results are in close agreement. Hence bagasse can be used in production of asbestos-free brake pad.

  4. Evaluation of Wear in Aftermarket Brake Pads for Enhancing Braking Performance in a Passenger Vehicle

    Directory of Open Access Journals (Sweden)

    Mohd Zaki Bahrom

    2016-08-01

    Full Text Available Nowadays, due to the high demands from the independence automotive service centers; there are many aftermarket brake pads available at spare parts shops and sold at reasonable prices. Several types of brake pads are available in the market such as semi-metallic and Non-Asbestos brake pads. The purpose of this study is to evaluate the wear of after-market brake pad performance under the normal driving conditions (highway and non-highway. Three types of aftermarket brake pads that mainly used and sold by independent service shop were selected in this study.  The data of the wear in thicknesses losses and weight percentage losses were recorded. The results show that brake pad of non- Asbestos Organic type gives the highest wear loss and create a lot of dust. For semi-metallic brake pad type, the result shows the lowest mass loss. Therefore, it is important to select the suitable type of after-market brake pads in order to get balance between cost and quality.

  5. Predict optimize the friction characteristics of brake pads; Brake pad no masatsu tokusei no yosoku to saitekika

    Energy Technology Data Exchange (ETDEWEB)

    Saotome, H. [Nissin Kogyo Co., Tokyo (Japan); Kato, T. [The University of Tokyo, Tokyo (Japan)

    1997-10-01

    The effect of the friction and the wear properties of brake pads were experimentally studied using a test rig of scale of 1/10 of the system used in a commercial car. The experimental data were investigated by the Multiple Regression Analysis and the Neural Network, and the effects of volume % of components on the friction and the wear properties were predicted. In addition the components of brake pads are optimized by Genetic Algorithms. 8 refs., 9 figs., 4 tabs.

  6. THE INFLUENCE OF BRAKE PADS THERMAL CONDUCTIVITY ON PASSANGER CAR BRAKE SYSTEM EFFICIENCY

    Directory of Open Access Journals (Sweden)

    Predrag D Milenković

    2010-01-01

    Full Text Available In phase of vehicle braking system designing, besides of mechanical characteristics, it is also necessary to take under consideration the system's thermal features. This is because it is not enough just to achieve proper braking power, for the brake system to be effective but equally important thing is the dissipation of heat to the environment. Heat developed in the friction surfaces dissipate into the environment over the disk in one hand and through the brake linings and caliper, in the other. The striving is to make that greatest amount of heat to dissipate not threw the brake pads but threw disc. The experimental researching of heat transfer process taking place at vehicle brakes was made in the R&D Center of "Zastava automobili" car factory in order to increase the efficiency of brake system. The standard laboratory and road test procedures were used, according to factory quality regulations. The modern equipment such as thermo camera, thermo couples, torque transducers, signal amplifiers, optical speed measuring system and laptop computer were used. In this paper will be shown the part of the experimental researching, which refers to the thermal conductivity of brake pad friction linings.

  7. Investigation on hardness and impact resistance of automotive brake pad composed with rice husk dust

    Science.gov (United States)

    Bahari, Shahril Anuar; Isa, Khairul Hafizee; Kassim, Masitah Abu; Mohamed, Zulkifli; Othman, Eliasidi Abu

    2012-06-01

    In this study, hardness and impact resistance properties of automotive brake pad composed with rice husk dust (RHD) were documented. RHD was mixed with other metallic and synthetic ingredients of automotive brake pad. To obtain RHD, rice husk was ground and dried to 1 - 3% moisture content. The RHD was screened to obtain different dust sizes (80 and 100-mesh) before it was mixed with other materials at different percentages of composition (10 and 30%). The mixture was then pressed to produce brake pad. Rockwell hardness testing machine was used in hardness determination, while Izod impact testing machine was used in impact resistance determination. Hardness resistance of automotive brake pad mixed with 10% composition and 80-mesh size of RHD was significantly higher than 100-mesh. Hardness resistance of automotive brake pad mixed with 30% composition and 100-mesh size of RHD was slightly higher than 80 mesh. However, based on analysis, the difference was not significant. According to the result, hardness resistance of automotive brake pad mixed with 30% composition of RHD was higher than 10%. RHD has filled up the space and enhanced the micro structural behaviour of automotive brake pad. Impact resistance of automotive brake pad mixed with 10% composition and 80-mesh size of RHD was insignificantly higher than 100-mesh. Impact resistance of automotive brake pad mixed with 30% composition and 80-mesh size of RHD was significantly higher than 100 mesh. Large RHD size has increased the capability to resist high-rated impact loading. The impact energy was distributed over wider area for larger particle size. This factor has increased the impact resistance of automotive brake pad from large dust size. Impact resistance of automotive brake pad mixed with 80-mesh size and 30% composition of RHD was higher than 10%. In contrast, impact resistance of automotive brake pad mixed with 100-mesh size and 10% composition of RHD was higher than 30%. However, the difference was not

  8. Speciation of Sb in airborne particulate matter, vehicle brake linings, and brake pad wear residues

    Science.gov (United States)

    Varrica, D.; Bardelli, F.; Dongarrà, G.; Tamburo, E.

    2013-01-01

    Insights into the speciation of Sb in samples of brake linings, brake pad wear residues, road dust, and atmospheric particulate matter PM10 and PM2.5 were obtained combining several well established and advanced characterization techniques, such as scanning electron microscopy - energy dispersive spectrometry (SEM-EDS), inductively coupled plasma mass spectrometry (ICP-MS) and synchrotron radiation X-ray absorption spectroscopy (SR-XAS). The advantage of SR-XAS is that samples do not undergo any chemical treatment prior to measurements, thus excluding possible alterations. These analyses revealed that the samples of wheel rims dust, road dust, and atmospheric particulate matter are composed by an admixture of Sb(III) and Sb(V) in different relative abundances. Brake linings turned out to be composed by Sb(III) oxide (Sb2O3) and stibnite (Sb2S3). Stibnite was also detected in some of the particulate matter samples. The obtained data suggest that Sb2S3 during the brake abrasion process is easily decomposed forming more stable compounds such as antimony mixed oxidic forms. Sb redox speciation, in particular and well studied circumstances, may enhance the potential and selectivity of this element as a tracer of motor vehicle emissions in apportioning studies.

  9. Compression Strength Testing for Automotive Brake Pads Used in Earthquake Energy Dampers

    Directory of Open Access Journals (Sweden)

    Dragoş Voiculescu

    2010-01-01

    Full Text Available In order to calibrate a friction damper which uses automotive brake pads it is necessary to determine the compression behaviour of the friction material. This paper summarizes the experimental results obtained for a set of automotive brake pads made in Romania. These results are useful in order to determine the slip load level in a seismic energy dissipation mechanism which uses this type of friction pads. The paper presents the experimental set up and the compression behaviour curves obtained for a set of four commercial brake pads. The testing was performed by the author as a part of his research work, using a hydraulic compression press.

  10. Research of Testing Devices That Determine Friction Parameter and Wear Resistance of Brake Pads

    OpenAIRE

    Timur, Mustafa; Kılıç, Halil

    2013-01-01

    The testing devices used today handles the variables such as speed, temperature, pressure occuring in automobiles due to various factors, and examines the impacts of these variables on brake pads in automobiles. In these devices, following experimental studies, the friction paramters, erosion resistance and thermal contacts of brake pads can be easily determined. Although it is quite easy to obtain information about the states of the materials using test device, testing devices have provided ...

  11. Thermal measurement of brake pad lining surfaces during the braking process

    Science.gov (United States)

    Piątkowski, Tadeusz; Polakowski, Henryk; Kastek, Mariusz; Baranowski, Pawel; Damaziak, Krzysztof; Małachowski, Jerzy; Mazurkiewicz, Łukasz

    2012-06-01

    This paper presents the test campaign concept and definition and the analysis of the recorded measurements. One of the most important systems in cars and trucks are brakes. The braking temperature on a lining surface can rise above 500°C. This shows how linings requirements are so strict and, what is more, continuously rising. Besides experimental tests, very supportive method for investigating processes which occur on the brake pad linings are numerical analyses. Experimental tests were conducted on the test machine called IL-68. The main component of IL-68 is so called frictional unit, which consists of: rotational head, which convey a shaft torque and where counter samples are placed and translational head, where samples of coatings are placed and pressed against counter samples. Due to the high rotational speeds and thus the rapid changes in temperature field, the infrared camera was used for testing. The paper presents results of analysis registered thermograms during the tests with different conditions. Furthermore, based on this testing machine, the numerical model was developed. In order to avoid resource demanding analyses only the frictional unit (described above) was taken into consideration. Firstly the geometrical model was performed thanks to CAD techniques, which in the next stage was a base for developing the finite element model. Material properties and boundary conditions exactly correspond to experimental tests. Computations were performed using a dynamic LS-Dyna code where heat generation was estimated assuming full (100%) conversion of mechanical work done by friction forces. Paper presents the results of dynamic thermomechanical analysis too and these results were compared with laboratory tests.

  12. Low-impact friction materials for brake pads

    OpenAIRE

    Bonfanti, Andrea

    2016-01-01

    State-of-the-art friction materials for applications in disc brake systems are constituted by composite materials, specifically formulated to ensure proper friction and wear performances, under the sliding contact conditions of braking events. The bases of typical friction compound formulations usually include 10 to 30 different components bonded with a polymeric binder cross-linked in situ. Main requests to be fulfilled during braking are an adequate friction efficiency and enough mechanical...

  13. Toxicity and mutagenicity of low-metallic automotive brake pad materials.

    Science.gov (United States)

    Malachova, Katerina; Kukutschova, Jana; Rybkova, Zuzana; Sezimova, Hana; Placha, Daniela; Cabanova, Kristina; Filip, Peter

    2016-09-01

    Organic friction materials are standardly used in brakes of small planes, railroad vehicles, trucks and passenger cars. The growing transportation sector requires a better understanding of the negative impact related to the release of potentially hazardous materials into the environment. This includes brakes which can release enormous quantities of wear particulates. This paper addresses in vitro detection of toxic and mutagenic potency of one model and two commercially available low-metallic automotive brake pads used in passenger cars sold in the EU market. The model pad made in the laboratory was also subjected to a standardized brake dynamometer test and the generated non-airborne wear particles were also investigated. Qualitative "organic composition" was determined by GC/MS screening of dichloromethane extracts. Acute toxicity and mutagenicity of four investigated sample types were assessed in vitro by bioluminescence assay using marine bacteria Vibrio fischeri and by two bacterial bioassays i) Ames test on Salmonella typhimurium His(-) and ii) SOS Chromotest using Escherichia coli PQ37 strain. Screening of organic composition revealed a high variety of organic compounds present in the initial brake pads and also in the generated non-airborne wear debris. Several detected compounds are classified by IARC as possibly carcinogenic to humans, e. g. benzene derivatives. Acute toxicity bioassay revealed a response of bacterial cells after exposure to all samples used. Phenolic resin and wear debris were found to be acutely toxic; however in term of mutagenicity the response was negative. All non-friction exposed brake pad samples (a model pad and two commercial pad samples) were mutagenic with metabolic activation in vitro. PMID:27179608

  14. 49 CFR 393.47 - Brake actuators, slack adjusters, linings/pads and drums/rotors.

    Science.gov (United States)

    2010-10-01

    ... drums/rotors. 393.47 Section 393.47 Transportation Other Regulations Relating to Transportation..., slack adjusters, linings/pads and drums/rotors. (a) General requirements. Brake components must be... on the lining shall not exceed 1.6 mm (1/16 inch). (g) Drums and rotors. The thickness of the...

  15. Evaluation of palm kernel fibers (PKFs for production of asbestos-free automotive brake pads

    Directory of Open Access Journals (Sweden)

    K.K. Ikpambese

    2016-01-01

    Full Text Available In this study, asbestos-free automotive brake pads produced from palm kernel fibers with epoxy-resin binder was evaluated. Resins varied in formulations and properties such as friction coefficient, wear rate, hardness test, porosity, noise level, temperature, specific gravity, stopping time, moisture effects, surface roughness, oil and water absorptions rates, and microstructure examination were investigated. Other basic engineering properties of mechanical overload, thermal deformation fading behaviour shear strength, cracking resistance, over-heat recovery, and effect on rotor disc, caliper pressure, pad grip effect and pad dusting effect were also investigated. The results obtained indicated that the wear rate, coefficient of friction, noise level, temperature, and stopping time of the produced brake pads increased as the speed increases. The results also show that porosity, hardness, moisture content, specific gravity, surface roughness, and oil and water absorption rates remained constant with increase in speed. The result of microstructure examination revealed that worm surfaces were characterized by abrasion wear where the asperities were ploughed thereby exposing the white region of palm kernel fibers, thus increasing the smoothness of the friction materials. Sample S6 with composition of 40% epoxy-resin, 10% palm wastes, 6% Al2O3, 29% graphite, and 15% calcium carbonate gave better properties. The result indicated that palm kernel fibers can be effectively used as a replacement for asbestos in brake pad production.

  16. Diagnostic procedure on brake pad assembly based on Young's modulus estimation

    International Nuclear Information System (INIS)

    Quality control of brake pads is an important issue, since the pad is a key component of the braking system. Typical damage of a brake pad assembly is the pad–backing plate detachment that affects and modifies the mechanical properties of the whole system. The most sensitive parameter to the damage is the effective Young's modulus, since the damage induces a decrease of the pad assembly stiffness and therefore of its effective Young's modulus: indeed its variation could be used for diagnostic purposes. The effective Young's modulus can be estimated from the first bending resonance frequency identified from the frequency response function measured on the pad assembly. Two kinds of excitation methods, i.e. conventional impulse excitation and magnetic actuation, will be presented and two different measurement sensors, e.g. laser Doppler vibrometer and microphone, analyzed. The robustness of the effective Young's modulus as a diagnostic feature will be demonstrated in comparison to the first bending resonance frequency, which is more sensitive to geometrical dimensions. Variability in the sample dimension, in fact, will induce a variation of the resonance frequency which could be mistaken for damage. The diagnostic approach has been applied to a set of undamaged and damaged pad assemblies showing good performance in terms of damage identification. The environmental temperature can be an important interfering input for the diagnostic procedure, since it influences the effective Young's modulus of the assembly. For that reason, a test at different temperatures in the range between 15 °C and 30 °C has been performed, evidencing that damage identification technique is efficient at any temperature. The robustness of the Young's modulus as a diagnostic feature with respect to damping is also presented. (paper)

  17. Friction and wear studies on the temperature dependence of brake-pad materials containing brass

    Directory of Open Access Journals (Sweden)

    Eddoumy Fatima

    2013-11-01

    Full Text Available Brake pad materials for automobile applications are basically polymer matrix composites. Various reinforcing constituents used in brake pads are organic, metallic and ceramic fillers which play among others an important role on the mechanical and thermal properties, and the wear resistance at high temperature. Friction and wear depend on various parameters such as the micro-chemical structure of the pad and of the metallic counter-face, the rotation speed, the pressure, and the contact surface temperature (M.G. Jacko 1983. This latter parameter can be locally as high as 600 up to 1.500 ∘C depending on the brake type (M.G. Jacko 1983; Blau 2001. Thermal models have been developed to study interface effects at contacting surfaces (Majcherczak, Dufrenoy et al. 2007. Frictional energy can be dissipated through different mechanisms such as oxidation, rise in temperature, formation of wear particles, entropy changes associated to viscoelastic and viscoplastic deformation, and noise generation (Eddoumy, Addiego et al. 2011. Studies of friction brake show that more than 95% of the dissipated energy is transformed into heat (Kasem, Thevenet et al.; Majcherczak, Dufrenoy et al. 2007. Thermal analysis is therefore a primordial step in the study of brake systems since it provides thermo-mechanical properties (Majcherczak, Dufrenoy et al. 2007. The influence of the addition of metallic fibers on the performance of organic friction composites has been investigated using friction tests (Qu, Zhang et al. 2004. Benefits or limitations of the different fibers have been reported, however the issues of thermo-mechanical properties or effect of temperature on friction and wear behavior were not yet investigated (Bijwe, Kumar et al. 2008. No effort was done to correlate the thermo-mechanical and thermal properties with the friction and wear behavior. An important prerequisite is to get a good understanding on how brake materials behave. However, a link

  18. Experimental Identification of Brake Pad Material Properties—A Step Towards a Better Prediction of Brake Squeal

    Science.gov (United States)

    Hornig, Sylwia; Hochlenert, Daniel; von Wagner, Utz

    2010-09-01

    Automotive brake squeal is a disruptive high frequency sound radiation phenomenon generated by friction-induced self-excited vibrations of the brake system. The brake system loses its stability and starts oscillating in a limit cycle with amplitudes limited by nonlinearities, the main origin of the nonlinearities being brake lining material. In order to perform a reliable brake squeal prediction using established mathematical-mechanical models, the knowledge of the lining material properties is of great importance. The present paper deals with the experimental identification of lining material properties, expecially referring to the elastic properties. Since these strongly vary depending on the operating conditions of brake systems, it is necessary to reproduce the operating conditions during brake squeal as close as possible in experimental setups. In this context a special test rig, the test data evaluation and the experimentally determined nonlinear elastic brake lining properties are presented. Assuming these brake lining properties to be the prominent source of the nonlinearity, a nonlinear stability analysis is performed on a realistic disk brake model. The results referring to brake squeal are discussed, whereas basic phenomena known from operating experience of brake systems can be explained on the basis of this analysis.

  19. Brake caliper with offset pads: Innovative brake technology for commercial vehicles offers opportunities to reduce weight and cost; Bremssattel mit tangential versetzten Bremsbelaegen: Innovative Radbremsentechnologie fuer Nutzfahrzeuge bietet neue Moeglichkeiten zur Gewichts- und Kostenreduzierung

    Energy Technology Data Exchange (ETDEWEB)

    Antony, P.; Blatt, P. [WABCO Radbremsen GmbH, Mannheim (Germany)

    2005-07-01

    Continuous optimizations and technical improvements showed no further potential for cost and weight reductions on basis of the conventional technique of a sliding caliper and two supported pads in the carrier. Additionally, global and technical needs are growing. With its 4th generation of air disc brakes and a new caliper concept, WABCO accounts to these developments. Characteristically for the New Generation (NG) is the caliper concept with pad offset in circumferential direction. This presentation describes construction and basics of the system, shows the usage of FEM and elements of Bionic methods and proofs its effectiveness with test bench results. Additional potential for the design of a new interfaces between brake and axle are identified. A significant improved disc cracking behavior offers possibilities for additional cost and weight savings. (orig.)

  20. Weight reduction of a standard brake drum: A design approach

    OpenAIRE

    D. Rambabu; R. Gopinath; U. Senthil rajan; G. B. Bhaskar

    2014-01-01

    A Brake drum is specialized brake that uses the concept of friction to decelerate the vehicle speed. The deceleration is achieved by the assistance of the friction generated by a set of brake shoes or pad, when operator presses against a rotating brake drum. The material generally preferred for making the brake drum is grey cast iron or vermicular cast iron. The drum brake is highly efficient for hand brake and service brake applications. During the operation of drum brake excessive heating o...

  1. Zavorne ploščice iz karboniziranega materiala za zavorne diske iz C/C-SiC: Carbonised-material-based brake pads for a C/C-SiC composite brake disc:

    OpenAIRE

    Stadler, Zmago

    2001-01-01

    Letely the brake discs from carbon-fibre-reinforced carbon composites infiltrated by silicon (LSI-process) have become very interesting for automotive brakes applications. Composite materials with a hard SiC layer on the surface of the disc (C/C-SiC) or composites with the fibre-reinforced ceramic structure (C/SiC) need the right brake-lining materials. The results of our new-brake-lining-material investigation for C/C-SiC brake discs are presented. The influence of some particular additives ...

  2. Method and apparatus for electromagnetically braking a motor

    Science.gov (United States)

    Davis, Donald R. (Inventor); Radford, Nicolaus A (Inventor); Permenter, Frank Noble (Inventor); Parsons, Adam H (Inventor); Mehling, Joshua S (Inventor)

    2011-01-01

    An electromagnetic braking system and method is provided for selectively braking a motor using an electromagnetic brake having an electromagnet, a permanent magnet, a rotor assembly, and a brake pad. The brake assembly applies when the electromagnet is de-energized and releases when the electromagnet is energized. When applied the permanent magnet moves the brake pad into frictional engagement with a housing, and when released the electromagnet cancels the flux of the permanent magnet to allow a leaf spring to move the brake pad away from the housing. A controller has a DC/DC converter for converting a main bus voltage to a lower braking voltage based on certain parameters. The converter utilizes pulse-width modulation (PWM) to regulate the braking voltage. A calibrated gap is defined between the brake pad and permanent magnet when the brake assembly is released, and may be dynamically modified via the controller.

  3. Brake assembly including torque monitor

    International Nuclear Information System (INIS)

    This patent describes a brake assembly for selectively braking rotation of an input shaft extending from a control rod drive having a longitudinal centerline axis, the shaft being rotatable for selectively inserting and withdrawing a control rod in a nuclear reactor vessel. It comprises a stationary base; an annular bearing mounted to the base; a brake mounted to the bearing; a backing plate mounted to the bearing; a first braking pad fixedly joined to the backing plate; a rotor disc fixedly connected to the input shaft and disposed adjacent to the first pad; a second braking pad disposed adjacent to the rotor disc; and means for selectively clamping the first and second pads against the rotor disc for braking the input shaft; means for torsionally restraining the brake including: a pin extending outwardly from the backing plate toward the base; and a spring extending from the base to the pin and generally perpendicular to the centerline axis; and means for monitoring the angle for monitoring braking torque capability of the brake

  4. Research on Heat-Mechanical Coupling of Ventilated Disc Brakes under the Condition of Emergency Braking

    Science.gov (United States)

    Tan, Xuelong; Zhang, Jian; Tang, Wenxian; Zhang, Yang

    Taking the ventilated disc brake in some company as research object, and using UG to build 3D models of brake disc and pad, and making use of ABAQUS/Standard to set up two parts' finite element model, via the decelerated motion of actual simulation brake disc, which gets ventilated disc brake in the case of emergency breaking in time and space distribution of conditions of temperature and stress field, summarizes the distribution of temperature field and stress field, proves complex coupling between temperature, stress, and supplies the direct basis for brake's fatigue life analysis.

  5. Gravity brake

    Science.gov (United States)

    Lujan, Richard E.

    2001-01-01

    A mechanical gravity brake that prevents hoisted loads within a shaft from free-falling when a loss of hoisting force occurs. A loss of hoist lifting force may occur in a number of situations, for example if a hoist cable were to break, the brakes were to fail on a winch, or the hoist mechanism itself were to fail. Under normal hoisting conditions, the gravity brake of the invention is subject to an upward lifting force from the hoist and a downward pulling force from a suspended load. If the lifting force should suddenly cease, the loss of differential forces on the gravity brake in free-fall is translated to extend a set of brakes against the walls of the shaft to stop the free fall descent of the gravity brake and attached load.

  6. 汽车刹车片用铁铜基摩擦材料的研究%Study of Fe and Cu-based P/M friction materials for automotive brake pads

    Institute of Scientific and Technical Information of China (English)

    陈文革; 罗启文; 张剑; 崔婷婷

    2012-01-01

    A kind of iron-copper based fricition material for automotive brake pad was prepared by powder metallurgy technology; mixing of electrolytic copper powder with particle size of 53 -14祄 and iron, graphite, titanium, nickel, silica, aluminum oxide and vulcanized molybdenum powder, compaction forming at 450 - SSOMPa, hot pressing sintering at 1 000t and pressure of 2. 5 - 2. SMPa for 1 - 2h. The microstmcture consist of iron and copper, ceramic, carbide and additives, the density and hardness of the friction materials is 5.57 g/cm3 and 227HV, respectively. By the wear testing, the wear rate and friction factor of the friction materials is 0. 002 6 g/min and 0.45,respectively. The influence factor of the friction materials is normal presser and rotate speed, the failure mechansm is adhere wear at first and grinding compound wear mostly.%采用粉末冶金热压技术制备铁铜基刹车片材料,进行磨损试验和扫描电镜观察.结果表明:将粒度53~74 μ,m的电解Cu粉、Fe粉、石墨、Ti、Ni、SiO2、Al2O3 MoS2混合均匀,于450~550MPa的压制压力下模压成形,在1 000℃、2.5~2.8MPa压力下N2保护热压1~2h,可制备出汽车刹车片用铁铜基摩擦材料.其显微组织由粘结的基体Fe、Cu相,耐磨的陶瓷、碳化物相和一些润滑相所构成;所制备材料的密度为5.57 g/cm3,平均硬度是227HV.影响其摩擦性能的主要因素是法向压力和转速,与钢的磨损速率为0.002 6 g/min,摩擦系数0.45;磨损的失效机理是先期粘着磨损,随后转化为磨料磨损,但以磨料磨损为主.

  7. 49 CFR 570.5 - Service brake system.

    Science.gov (United States)

    2010-10-01

    ...) Friction materials. On each brake the thickness of the lining or pad shall not be less than one thirty... CFR 571.105, on every new passenger car manufactured on or after January 1, 1968, and on other types... from loose material, oil, or grease. The service brakes shall be applied at a vehicle speed of 20...

  8. 49 CFR 570.59 - Service brake system.

    Science.gov (United States)

    2010-10-01

    ...) Friction materials. On each brake, the thickness of the lining or pad shall not be less than one thirty-second of an inch over the fastener, or one-sixteenth of an inch over the brake shoe on bonded linings or... percent grade), dry, smooth, hard-surfaced road that is free from loose material, oil or grease....

  9. Weight reduction of a standard brake drum: A design approach

    Directory of Open Access Journals (Sweden)

    D. Rambabu

    2014-03-01

    Full Text Available A Brake drum is specialized brake that uses the concept of friction to decelerate the vehicle speed. The deceleration is achieved by the assistance of the friction generated by a set of brake shoes or pad, when operator presses against a rotating brake drum. The material generally preferred for making the brake drum is grey cast iron or vermicular cast iron. The drum brake is highly efficient for hand brake and service brake applications. During the operation of drum brake excessive heating of brake drum may occur. This excessive heating occurs due to repeated or frequent contact of the brake shoes against the drum. This causes the drum to crack, oversize, extreme wear, out of round drums and also leads to vibration which while braking will leads to reduced brake drum life and braking efficiency. The Un-laden weight of the vehicle will result in increased fuel consumption, reduced payload and ride handling characteristics. The objective of the paper is to improve the thermal characteristics by incorporating fins in the brake drum and to reduce the un-laden weight of the vehicle by changing the rib thickness, wall thickness and base flange thickness. The design is done by using 3D CAD Modelling software and Hexahedral finite element model prepared by using CAE pre-processing software and Stiffness analysis. Design iterations are carried out by using Linear/Non-linear Finite Element Solvers, Stress Displacement and Temperature is post-processed for design validation. Optimized design solution obtained based on the comparison study between the iteration with rib thickness 75 mm, star shaped removal and wall thickness 17 mm has been chosen. 1.8Kg of weight is being reduced from the brake drum including fins.   Keywords: Drum Brake, 3D CAD Modelling, Para Metric Matrix, Structural Analysis, Fins.

  10. Friction characteristics of a brake friction material under different braking conditions

    International Nuclear Information System (INIS)

    Highlights: • The tribological behavior of the brake material is well depending on interfacial temperature and friction conditions. • The friction performance is influenced by the material heterogeneity and its anisotropy. • The friction performance depended on the nature, morphology and orientation of constituents. - Abstract: As the evaluation of the tribological properties of the brake lining material is important for the braking performance identification, a pad-on-disc friction and wear tests of a commercial brake pad material against cast iron disc were conducted under low, middle and severe conditions. Three experiments via (t1), (t2) and (t3) with different sliding speeds and nominal contact pressure were conducted. Tests were performed with the pad in periodic sliding contact for 30 cycles. The scanning electronic microscopic (SEM) analysis with energy dispersive X-ray (EDX) was used to characterize the rubbed surface. The results showed that during the run-in period, the coefficient of friction increases steadily. For the friction mechanism: (i) at lower conditions, a stable friction film was generated on the surface of the brake pad, providing excellent friction stability with less wear, (ii) at middle conditions, fibers were agglomerated and were not contributed more, and (iii) at higher conditions, contact plates were identified which were accommodated the speed and the load

  11. Experimental investigations for uncertainty quantification in brake squeal analysis

    Science.gov (United States)

    Renault, A.; Massa, F.; Lallemand, B.; Tison, T.

    2016-04-01

    The aim of this paper is to improve the correlation between the experimental and the numerical prediction of unstable frequencies for automotive brake systems considering uncertainty. First, an experimental quantification of uncertainty and a discussion analysing the contributions of uncertainty to a numerical squeal simulation are proposed. Frequency and transient simulations are performed considering nominal values of model parameters, determined experimentally. The obtained results are compared with those derived from experimental tests to highlight the limitation of deterministic simulations. The effects of the different kinds of uncertainty detected in working conditions of brake system, the pad boundary condition, the brake system material properties and the pad surface topography are discussed by defining different unstable mode classes. Finally, a correlation between experimental and numerical results considering uncertainty is successfully proposed for an industrial brake system. Results from the different comparisons reveal also a major influence of the pad topography and consequently the contact distribution.

  12. Boric acid effect in phenolic composites on tribological properties in brake linings

    International Nuclear Information System (INIS)

    In the present work, using a pad-on-disc-type wear tester, the tribological properties of the pad next to the disk made of cast iron were investigated with changing the substance of the components. As well, micro-structural characterisation of braking pads was performed using scanning electron microscopy and also temperature outcome of the pads was examined at the temperatures of 50-400 oC in the pressure of 1050 and 3000 kPa. Finally, the effect of environment to the pads was studied in water, salty water, oil and braking liquid media

  13. Study on antilock brake system with elastic membrane vibration generated by controlled solenoid excitation

    Science.gov (United States)

    Wibowo, Zakaria, Lambang, Lullus; Triyono, Muhayat, Nurul

    2016-03-01

    The most effective chassis control system for improving vehicle safety during severe braking is anti-lock braking system (ABS). Antilock effect can be gained by vibrate the pad brake at 7 to 20 cycle per second. The aim of this study is to design a new method of antilock braking system with membrane elastic vibrated by solenoid. The influence of the pressure fluctuations of brake fluid is investigated. Vibration data is collected using a small portable accelerometer-slam stick. The experiment results that the vibration of brake pad caused by controlled solenoid excitation at 10 Hz is obtained by our new method. The result of measurements can be altered by varying brake fluid pressure.

  14. Thermal-mechanical coupled analysis of a brake disk rotor

    Science.gov (United States)

    Belhocine, Ali; Bouchetara, Mostefa

    2013-08-01

    The main purpose of this study is to analyze the thermomechanical behavior of the dry contact between the brake disk and pads during the braking phase. The simulation strategy is based on computer code ANSYS11. The modeling of transient temperature in the disk is actually used to identify the factor of geometric design of the disk to install the ventilation system in vehicles The thermal-structural analysis is then used with coupling to determine the deformation and the Von Mises stress established in the disk, the contact pressure distribution in pads. The results are satisfactory when compared to those of the specialized literature.

  15. TGV disc brake squeal

    Science.gov (United States)

    Lorang, X.; Foy-Margiocchi, F.; Nguyen, Q. S.; Gautier, P. E.

    2006-06-01

    The discomfort generated by the noise emission of braking systems in trains has aroused recently many studies on the mechanical modelling of brake noise in France. A theoretical and numerical discussion on the phenomenon of brake squeal is given in this paper in relation with some experimental data. This study is based upon a flutter instability analysis giving unstable modes of the brake system under the contact and Coulomb friction.

  16. Nonlinear transient and chaotic interactions in disc brake squeal

    Science.gov (United States)

    Oberst, S.; Lai, J. C. S.

    2015-04-01

    In automotive disc-brake squeal, most numerical studies have been focussed on the prediction of unstable vibration modes in the frequency domain using the complex eigenvalue analysis. However, the magnitude of the positive real part of a complex eigenvalue is an unreliable indicator of squeal occurrence. Although nonlinearities have been shown to play a significant role in brake squeal, transient nonlinear time domain analyses have rarely been applied owing to high computational costs. Here the complex eigenvalue analysis, the direct steady-state analysis and the transient nonlinear time domain analysis are applied to an isotropic pad-on-disc finite element model representing a simple model of a brake system. While in this investigation, in-plane pad-mode instabilities are not detected by the complex eigenvalue analysis, the dissipated energy obtained by the direct steady-state analysis of the model subjected to harmonic contact pressure excitation is negative at frequencies of pad modes, indicating a potential for instabilities. Transient nonlinear time domain analysis of the pad and disc dynamics reveal that in-plane pad vibrations excite a dominant out-of-plane disc mode. For intermittently chaotic pad motion, the disc dynamics is quasi-periodic; and for chaotic motion of the pad, a toroidal attractor is found for the disc's out-of-plane motion. Nonlinear interactions between the pad and the disc highlight that different parts in a brake system display different dynamic behaviour and need to be analysed separately. The type II intermittency route to chaos could be the cause for the experimentally observed instantaneous mode squeal.

  17. Squeal analysis of ventilated disc brake using ansys

    Directory of Open Access Journals (Sweden)

    Ahmed Abdel-Naser, Ibrahim Ahmed, Essam Allam, Sabry Allam, Shawki Abouel-seoud

    2012-01-01

    Full Text Available It is well-known that automobile brakes can generate several kinds of noises. Among them is squeal, a noise in the 1-15 kHz range. It is commonly accepted that brake squeal is initiated by instability due to the friction forces, leading to self excited vibrations. To predict the onset of brake instability, a modal analysis of the prestressed structure can be performed on an improved dynamic finite element model of ventilated disc brake with friction coupling. An unsymmetric stiffness matrix is a result of the friction coupling between the brake pad and disc; this may lead to complex eigenfrequencies. The complex eigenvalue method (Unsymmetric solver used to analyse mode shapes associated with the predicted natural frequency. Creating the element of Matrix27 between the ventilated disc and pad was very important in studying the squeal of the coupled ventilated disc brake. The results demonstrated that the FEM for the coupled ventilated rotor and pad showed a good interaction between the non-linear contact and the linear modal analysis. Furthermore, the unsymmetric solver showed that the modes of the coupled disc-pad contained two types of mode. The first type was normal mode, which did not contain an imaginary part while the second type was complex mode that contained real and imaginary parts. Moreover, complex eigenvalue analysis predicted always more unstable modes than the number of squeal frequencies that really occur in the brake system. The maximum squeal index was observed at mode 16 and at frequency of 4083 Hz with instability of 480 sec-1. However; the tendency of instability (TOI for the system at contact stiffness of 1 GN/m was 59 that gave the lowest instability of the system.

  18. Pulsar Braking Indices Revisited

    CERN Document Server

    Johnston, S; Johnston, Simon; Galloway, David

    1999-01-01

    Using the standard equation for the slowdown of a neutron star, we derive a formula for the braking index via integration rather than the conventional differentiation. The new formula negates the need to measure the second time derivative of the rotation frequency. We show that the method gives similar braking indices for PSR B1509-58 and the Crab pulsar to those already in the literature. We point out that our method is useful for obtaining the braking indices of moderate aged pulsars without the need for long, phase-connected timing solutions. We applied the method to 20 pulsars and discuss the implications of the results. We find that virtually all the derived braking indices are dominated by the effects of (unseen) glitches, the recovery from which corrupts the value of the frequency first derivative. However, any real, large, positive braking index has implications for magnetic field decay and offers support to recent models of pulsar evolution.

  19. WIND BRAKING OF MAGNETARS

    Energy Technology Data Exchange (ETDEWEB)

    Tong, H. [Xinjiang Astronomical Observatory, Chinese Academy of Sciences, Urumqi, Xinjiang 830011 (China); Xu, R. X.; Qiao, G. J. [KIAA and School of Physics, Peking University, Beijing 100871 (China); Song, L. M., E-mail: tonghao@xao.ac.cn [Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China)

    2013-05-10

    We explore the wind braking of magnetars considering recent observations challenging the traditional magnetar model. There is evidence for strong multipole magnetic fields in active magnetars, but the dipole field inferred from spin-down measurements may be strongly biased by particle wind. Recent observations challenging the traditional model of magnetars may be explained naturally by the wind braking scenario: (1) the supernova energies of magnetars are of normal value; (2) the non-detection in Fermi observations of magnetars; (3) the problem posed by low magnetic field soft gamma-ray repeaters; (4) the relation between magnetars and high magnetic field pulsars; and (5) a decreasing period derivative during magnetar outbursts. Transient magnetars with L{sub x}<- E-dot{sub rot} may still be magnetic dipole braking. This may explain why low luminosity magnetars are more likely to have radio emissions. A strong reduction of the dipole magnetic field is possible only when the particle wind is very collimated at the star surface. A small reduction of the dipole magnetic field may result from detailed considerations of magnetar wind luminosity. In the wind braking scenario, magnetars are neutron stars with a strong multipole field. For some sources, a strong dipole field may no longer be needed. A magnetism-powered pulsar wind nebula will be one of the consequences of wind braking. For a magnetism-powered pulsar wind nebula, we should see a correlation between the nebula luminosity and the magnetar luminosity. Under the wind braking scenario, a braking index smaller than three is expected. Future braking index measurement of a magnetar may tell us whether magnetars are wind braking or magnetic dipole braking.

  20. WIND BRAKING OF MAGNETARS

    International Nuclear Information System (INIS)

    We explore the wind braking of magnetars considering recent observations challenging the traditional magnetar model. There is evidence for strong multipole magnetic fields in active magnetars, but the dipole field inferred from spin-down measurements may be strongly biased by particle wind. Recent observations challenging the traditional model of magnetars may be explained naturally by the wind braking scenario: (1) the supernova energies of magnetars are of normal value; (2) the non-detection in Fermi observations of magnetars; (3) the problem posed by low magnetic field soft gamma-ray repeaters; (4) the relation between magnetars and high magnetic field pulsars; and (5) a decreasing period derivative during magnetar outbursts. Transient magnetars with Lxrot may still be magnetic dipole braking. This may explain why low luminosity magnetars are more likely to have radio emissions. A strong reduction of the dipole magnetic field is possible only when the particle wind is very collimated at the star surface. A small reduction of the dipole magnetic field may result from detailed considerations of magnetar wind luminosity. In the wind braking scenario, magnetars are neutron stars with a strong multipole field. For some sources, a strong dipole field may no longer be needed. A magnetism-powered pulsar wind nebula will be one of the consequences of wind braking. For a magnetism-powered pulsar wind nebula, we should see a correlation between the nebula luminosity and the magnetar luminosity. Under the wind braking scenario, a braking index smaller than three is expected. Future braking index measurement of a magnetar may tell us whether magnetars are wind braking or magnetic dipole braking.

  1. Wind Braking of Magnetars

    Science.gov (United States)

    Tong, H.; Xu, R. X.; Song, L. M.; Qiao, G. J.

    2013-05-01

    We explore the wind braking of magnetars considering recent observations challenging the traditional magnetar model. There is evidence for strong multipole magnetic fields in active magnetars, but the dipole field inferred from spin-down measurements may be strongly biased by particle wind. Recent observations challenging the traditional model of magnetars may be explained naturally by the wind braking scenario: (1) the supernova energies of magnetars are of normal value; (2) the non-detection in Fermi observations of magnetars; (3) the problem posed by low magnetic field soft gamma-ray repeaters; (4) the relation between magnetars and high magnetic field pulsars; and (5) a decreasing period derivative during magnetar outbursts. Transient magnetars with L_x{rot may still be magnetic dipole braking. This may explain why low luminosity magnetars are more likely to have radio emissions. A strong reduction of the dipole magnetic field is possible only when the particle wind is very collimated at the star surface. A small reduction of the dipole magnetic field may result from detailed considerations of magnetar wind luminosity. In the wind braking scenario, magnetars are neutron stars with a strong multipole field. For some sources, a strong dipole field may no longer be needed. A magnetism-powered pulsar wind nebula will be one of the consequences of wind braking. For a magnetism-powered pulsar wind nebula, we should see a correlation between the nebula luminosity and the magnetar luminosity. Under the wind braking scenario, a braking index smaller than three is expected. Future braking index measurement of a magnetar may tell us whether magnetars are wind braking or magnetic dipole braking.

  2. Hover Pad

    DEFF Research Database (Denmark)

    Seifert, Julian; Boring, Sebastian; Winkler, Christian; Schaub, Florian; Schwab, Fabian; Herrdum, Steffen; Maier, Fabian; Mayer, Daniel; Rukzio, Enrico

    Handheld displays enable flexible spatial exploration of information spaces - users can physically navigate through three-dimensional space to access information at specific locations. Having users constantly hold the display, however, has several limitations: (1) inaccuracies due to natural hand...... tremors; (2) fatigue over time; and (3) limited exploration within arm's reach. We investigate autonomous, self-actuated displays that can freely move and hold their position and orientation in space without users having to hold them at all times. We illustrate various stages of such a display's autonomy...... ranging from manual to fully autonomous, which - depending on the tasks - facilitate the interaction. Further, we discuss possible motion control mechanisms for these displays and present several interaction techniques enabled by such displays. Our Hover Pad toolkit enables exploring five degrees of...

  3. Development of hydraulic brake actuator for active brake control; Active brake seigyoyo yuatsu booster no kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    Konishi, Y.; Hattori, M. Sugisawa, M.; Nishii, M. [Aisin Seiki Co. Ltd., Aichi (Japan)

    1997-10-01

    Recently, application of active brake control systems of the vehicle are increasing. (Vehicle stability control, Panic brake assist ) We have developed a new hydraulic brake actuator for active brake control systems. New hydraulic brake actuator is composed of the three parts. (Hydraulic booster unit, Power supply unit, Control valve unit) This report describes the construction of the new hydraulic booster unit. 2 refs., 10 figs.

  4. Braking System Modeling and Brake Temperature Response to Repeated Cycle

    Directory of Open Access Journals (Sweden)

    Zaini Dalimus

    2014-12-01

    Full Text Available Braking safety is crucial while driving the passenger or commercial vehicles. Large amount of kinetic energy is absorbed by four brakes fitted in the vehicle. If the braking system fails to work, road accident could happen and may result in death. This research aims to model braking system together with vehicle in Matlab/Simulink software and measure actual brake temperature. First, brake characteristic and vehicle dynamic model were generated to estimate friction force and dissipated heat. Next, Arduino based prototype brake temperature monitoring was developed and tested on the road. From the experiment, it was found that brake temperature tends to increase steadily in long repeated deceleration and acceleration cycle.

  5. Development of brake assist system. Summary of hydraulic brake assist system; Brake assist system no kaihatsu. Ekiatsushiki brake assist system no gaiyo

    Energy Technology Data Exchange (ETDEWEB)

    Hara, M.; Ota, M.; Shimizu, S. [Toyota, Motor Corp., Aichi (Japan)

    1997-10-01

    We have already developed vacuum-booster-type Brake Assist System that supplies additional braking power when panic braking is recognized. We are convinced that the expansion of Brake Assist System will become more important issue in the future. Therefore we have developed hydraulic Brake Assist System with increasing its controllability and reducing its discomfort. This system have a brake pressure sensor to detect emergency braking operation and an antilock device to supply additional braking power. 8 refs., 11 figs.

  6. Thermomechanical behavior of dry contacts in disc brake rotor with a grey cast iron composition

    Directory of Open Access Journals (Sweden)

    Belhocine Ali

    2013-01-01

    Full Text Available The main purpose of this study is to analysis the thermomechanical behavior of the dry contact between the brake disc and pads during the braking phase. The simulation strategy is based on the calculation code ANSYS11. The modeling of transient temperature in the disk is actually used to identify the factor of geometric design of the disk to install the ventilation system in vehicles. The thermal-structural analysis is then used coupling to determine the deformation established and the Von Mises stresses in the disk, the contact pressure distribution in pads. The results are satisfactory compared to those found in the literature.

  7. Development of mechanical brake assist; Mechanical brake assist no kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    Konishi, M.; Shingyoji, S.; Nakamura, I.; Tagawa, T.; Saito, Y.; Ishihara, T.; Kobayashi, S.; Yoshida, M. [Nissan Motor Co. Ltd., Tokyo (Japan)

    1997-10-01

    We have recognized that there are drivers who cannot apply strong brake pedal force , in spite of the necessity of hard braking in emergencies. We have developed a `mechanical brake assist system` which assists drivers appropriately, according to the drivers` characteristics based on studying the characteristic`s of conditions of drivers applying the brake pedal force in emergency conditions. 2 refs., 7 figs., 1 tab.

  8. Compositions, Functions, and Testing of Friction Brake Materials and Their Additives

    Energy Technology Data Exchange (ETDEWEB)

    Blau, PJ

    2001-10-22

    The purpose of this report is to present a survey of commercial brake materials and additives, and to indicate their typical properties and functions, especially as regards their use in heavy trucks. Most truck pad and shoe materials described here were designed to wear against cast iron. Brake material test methods are also briefly described. This report does not address issues associated with the fabrication and manufacturing of brake materials. Since there are literally thousands of brake material additives, and their combinations are nearly limitless, it is impractical to list them all here. Rather, an attempt has been made to capture the primary constituents and their functions. An Appendix contains thermo-physical properties of some current and potential brake materials.

  9. 49 CFR 393.52 - Brake performance.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 5 2010-10-01 2010-10-01 false Brake performance. 393.52 Section 393.52... NECESSARY FOR SAFE OPERATION Brakes § 393.52 Brake performance. (a) Upon application of its service brakes... braking force is measured by a performance-based brake tester which meets the requirements of...

  10. Microstructural analysis of organic disc pads in service

    International Nuclear Information System (INIS)

    The structural analysis of the commercially used brake pads on the rubbed surfaces have been assessed using the combination method of X-ray analysis, optical and scanning electron microscopy. It has been found that the rubbed surface comprised of complex compounds and non-homogeneous particle sizes distribution. The Cu/Zn alloys which have been used as friction chips were smeared across the rubbed surface and the identification of the barium oxide compounds indicated that the thermal decomposition reaction of the mechanically decomposed barytes during the brake in service

  11. Development of combined brake system on front and rear brakes for scooter; Scooter yo zenkorin rendo brake system no kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    Okazaki, Y.; Itabashi, T.; Shinohara, S.; Honda, Y. [Honda R and D Co. Ltd., Tokyo (Japan)

    1997-10-01

    Scooters need appropriate front and rear wheel braking power distribution and each of front and rear brakes have been operated using right and left levers. This time, a low cost brakes with cable type combined brake system for small size scooter and a brakes with hydraulic type combined brake system for middle size scooter have been developed to obtain appropriate front and rear wheel braking power distribution. Both systems use convenient left lever to operate. 3 refs., 9 figs., 1 tab.

  12. Wind braking of magnetars

    CERN Document Server

    Tong, H; Song, L M; Qiao, G J

    2012-01-01

    Anomalous X-ray pulsars (AXPs) and soft gamma-ray repeaters (SGRs) are magnetar candidates. During their studies, the magnetic dipole braking mechanism is often assumed. This will result in a high surface dipole field for most AXPs and SGRs. It will also bring several problems challenging the magnetar interpretation. Alternatively, it is possible that AXPs and SGRs are braked down by a particle wind which also originates from magnetic field decay. In the wind braking scenario, magnetars are neutron stars with strong multipole field. A strong dipole field is no longer required. Recent challenging observations of magnetars may be explained naturally in the wind braking scenario: (1) The supernova energetics of those associated with magnetars are of normal value; (2) The non-detection in Fermi observations of magnetars; (3) The problem posed by the low-magnetic field soft gamma-ray repeater; (4) The relation between magnetars and high magnetic field pulsars ; (5) A decreasing period derivative during magnetar ou...

  13. Comparative analysis into the tractor-trailer braking dynamics: tractor with single axle brakes, tractor with all wheel brakes

    Science.gov (United States)

    Nastasoiu, Mircea; Ispas, Nicolae

    2014-06-01

    The paper elaborates a mathematical model in order to conduct a study into the dynamics of tractor-trailer systems during braking. The braking dynamics is analyzed by considering two versions for the braking system: 1) braking applied on the rear axle and 2) braking applied on all four wheels. In both versions the trailer is braked on all wheels. The mathematical model enables us to determine and graphically illustrate the evolution of the following parameters: braking deceleration, braking speed and the distance traveled by the tractor during braking. The mathematical model elaborated is applied on a tractor-trailer system completing transportation works.

  14. Laboratory testing of airborne brake wear particle emissions using a dynamometer system under urban city driving cycles

    Science.gov (United States)

    Hagino, Hiroyuki; Oyama, Motoaki; Sasaki, Sousuke

    2016-04-01

    To measure driving-distance-based mass emission factors for airborne brake wear particulate matter (PM; i.e., brake wear particles) related to the non-asbestos organic friction of brake assembly materials (pads and lining), and to characterize the components of brake wear particles, a brake wear dynamometer with a constant-volume sampling system was developed. Only a limited number of studies have investigated brake emissions under urban city driving cycles that correspond to the tailpipe emission test (i.e., JC08 or JE05 mode of Japanese tailpipe emission test cycles). The tests were performed using two passenger cars and one middle-class truck. The observed airborne brake wear particle emissions ranged from 0.04 to 1.4 mg/km/vehicle for PM10 (particles up to 10 μm (in size), and from 0.04 to 1.2 mg/km/vehicle for PM2.5. The proportion of brake wear debris emitted as airborne brake wear particles was 2-21% of the mass of wear. Oxygenated carbonaceous components were included in the airborne PM but not in the original friction material, which indicates that changes in carbon composition occurred during the abrasion process. Furthermore, this study identified the key tracers of brake wear particles (e.g., Fe, Cu, Ba, and Sb) at emission levels comparable to traffic-related atmospheric environments.

  15. About Peripheral Artery Disease (PAD)

    Science.gov (United States)

    ... Tools & Resources Stroke More About Peripheral Artery Disease (PAD) Updated:Mar 23,2016 Peripheral artery disease (PAD) ... critical regions of the body. Quick Facts about PAD View an illustration of PAD The most common ...

  16. Experiments with airplane brakes

    Science.gov (United States)

    Michael, Franz

    1931-01-01

    This report begins by examining the forces on the brake shoes. For the determination of the load distribution over the shoes it was assumed that the brake linings follow Hooke's law, are neatly fitted and bedded in by wear. The assumption of Hooke's law, that is, the proportionality between compression of the lining and the absorption of force, is fulfilled to a certain extent for the loading, as becomes apparent from the load tests described further on. But there is a material discrepancy at unloading. From the load distribution we merely defined the position of the normal force resultant, while for the rest, the effect of the distribution was disregarded in the comparison of the different shoe dispositions.

  17. Tether Deployer And Brake

    Science.gov (United States)

    Carroll, Joseph A.; Alexander, Charles M.

    1993-01-01

    Design concept promises speed, control, and reliability. Scheme for deploying tether provides for fast, free, and snagless payout and fast, dependable braking. Developed for small, expendable tethers in outer space, scheme also useful in laying transoceanic cables, deploying guidance wires to torpedoes and missiles, paying out rescue lines from ship to ship via rockets, deploying antenna wires, releasing communication and power cables to sonobuoys and expendable bathythermographs, and in reeling out lines from fishing rods.

  18. Evaluation of the deposition, translocation and pathological response of brake dust with and without added chrysotile in comparison to crocidolite asbestos following short-term inhalation: Interim results

    International Nuclear Information System (INIS)

    Chrysotile has been frequently used in the past in manufacturing brakes and continues to be used in brakes in many countries. This study was designed to provide an understanding of the biokinetics and potential toxicology following inhalation of brake dust following short term exposure in rats. The deposition, translocation and pathological response of brake dust derived from brake pads manufactured with chrysotile were evaluated in comparison to the amphibole, crocidolite asbestos. Rats were exposed by inhalation 6 h/day for 5 days to either brake dust obtained by sanding of brake-drums manufactured with chrysotile, a mixture of chrysotile and the brake dust or crocidolite asbestos. No significant pathological response was observed at any time point in either the brake dust or chrysotile/brake dust exposure groups. The long chrysotile fibers (> 20 μm) cleared quickly with T1/2 estimated as 30 and 33 days, respectively in the brake dust and the chrysotile/brake dust exposure groups. In contrast, the long crocidolite fibers had a T1/2 > 1000 days and initiated a rapid inflammatory response in the lung following exposure resulting in a 5-fold increase in fibrotic response within 91 days. These results provide support that brake dust derived from chrysotile containing brake drums would not initiate a pathological response in the lung following short term inhalation. - Highlights: • We evaluated brake dust w/wo added chrysotile in comparison to crocidolite asbestos. • Persistence, translocation, pathological response in the lung and pleural cavity. • Chrysotile cleared rapidly from the lung while the crocidolite asbestos persisted. • No significant pathology observed at any time point in the brake-dust groups. • Crocidolite produced pathological response - Wagner 4 interstitial fibrosis by 32d

  19. The Comparative Analysis and Evaluation of Ecological Characteristics of Drum and Disk Wheel Brakes

    Directory of Open Access Journals (Sweden)

    Aleksandr Revin

    2011-04-01

    Full Text Available It is well-known that automobile transport as well as industry are the main sources of air pollution. In addition to exhaust gases, the flow of traffic releases a cloud of dust, consisting of over 60% of micro- and ultramicroscopic particles with radius of 10.0–0.25 µm, which are formed due to wheel abrasion (caused by the road grip of a tyre and the use of the brake blocks (in braking. The products formed in the process of wearing of the wheel brake pads are also the sources of the mass of fine dispersed particles over an urban highway. The authors analyse and evaluate ecological characteristics of drum and disk wheel brakes of vehicles.Article in Russian

  20. 49 CFR 570.57 - Air brake system and air-over-hydraulic brake subsystem.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 6 2010-10-01 2010-10-01 false Air brake system and air-over-hydraulic brake... STANDARDS Vehicles With GVWR of More Than 10,000 Pounds § 570.57 Air brake system and air-over-hydraulic brake subsystem. The following requirements apply to vehicles with air brake and...

  1. Pulsar braking: magnetodipole vs. wind

    CERN Document Server

    Tong, H

    2015-01-01

    Pulsars are good clocks in the universe. One fundamental question is that why they are good clocks? This is related to the braking mechanism of pulsars. Nowadays pulsar timing is done with unprecedented accuracy. More pulsars have braking indices measured. The period derivative of intermittent pulsars and magnetars can vary by a factor of several. However, during pulsar studies, the magnetic dipole braking in vacuum is still often assumed. It is shown that the fundamental assumption of magnetic dipole braking (vacuum condition) does not exist and it is not consistent with the observations. The physical torque must consider the presence of the pulsar magnetosphere. Among various efforts, the wind braking model can explain many observations of pulsars and magnetars in a unified way. It is also consistent with the up-to-date observations. It is time for a paradigm shift in pulsar studies: from magnetic dipole braking to wind braking. As one alternative to the magnetospheric model, the fallback disk model is also...

  2. Pulsar braking: magnetodipole vs. wind

    Science.gov (United States)

    Tong, Hao

    2016-01-01

    Pulsars are good clocks in the universe. One fundamental question is that why they are good clocks? This is related to the braking mechanism of pulsars. Nowadays pulsar timing is done with unprecedented accuracy. More pulsars have braking indices measured. The period derivative of intermittent pulsars and magnetars can vary by a factor of several. However, during pulsar studies, the magnetic dipole braking in vacuum is still often assumed. It is shown that the fundamental assumption of magnetic dipole braking (vacuum condition) does not exist and it is not consistent with the observations. The physical torque must consider the presence of the pulsar magnetosphere. Among various efforts, the wind braking model can explain many observations of pulsars and magnetars in a unified way. It is also consistent with the up-to-date observations. It is time for a paradigm shift in pulsar studies: from magnetic dipole braking to wind braking. As one alternative to the magnetospheric model, the fallback disk model is also discussed.

  3. Transient switching control strategy from regenerative braking to anti-lock braking with a semi-brake-by-wire system

    Science.gov (United States)

    Li, Liang; Li, Xujian; Wang, Xiangyu; Liu, Yahui; Song, Jian; Ran, Xu

    2016-02-01

    Regenerative braking is an important technology in improving fuel economy of an electric vehicle (EV). However, additional motor braking will change the dynamic characteristics of the vehicle, leading to braking instability, especially when the anti-lock braking system (ABS) is triggered. In this paper, a novel semi-brake-by-wire system, without the use of a pedal simulator and fail-safe device, is proposed. In order to compensate for the hysteretic characteristics of the designed brake system while ensure braking reliability and fuel economy when the ABS is triggered, a novel switching compensation control strategy using sliding mode control is brought forward. The proposed strategy converts the complex coupling braking process into independent control of hydraulic braking and regenerative braking, through which a balance between braking performance, braking reliability, braking safety and fuel economy is achieved. Simulation results show that the proposed strategy is effective and adaptable in different road conditions while the large wheel slip rate is triggered during a regenerative braking course. The research provides a new possibility of low-cost equipment and better control performance for the regenerative braking in the EV and the hybrid EV.

  4. ForcePAD

    DEFF Research Database (Denmark)

    Lindemann, J.; Damkilde, Lars

    2009-01-01

    ForcePAD is a 2-dimensional finite element application that started as a concept application for finite element modeling. Over the course of 10 years the application has been evolved into an application that is used extensively in both an educational setting as well as a tool for design and engin...... engineering. In the latest version of ForcePAD an optimization module was added to enable to take advantage of topology optimization in the design process....

  5. The Role of Solid Lubricants for Brake Friction Materials

    Directory of Open Access Journals (Sweden)

    Werner Österle

    2016-02-01

    Full Text Available This review article comprises of three parts. Firstly, reports of brake manufacturers on the beneficial impact of solid lubricants for pad formulations are surveyed. Secondly, since tribofilms were identified to play a crucial role in friction stabilization and wear reduction, the knowledge about tribofilm structures formed during automotive braking was reviewed comprehensively. Finally, a model for simulating the sliding behavior of tribofilms is suggested and a review on modelling efforts with different model structures related to real tribofilms will be presented. Although the variety of friction composites involved in commercial brake systems is very broad, striking similarities were observed in respect to tribofilm nanostructures. Thus, a generalization of the tribofilm nanostructure is suggested and prerequisites for smooth sliding performance and minimal wear rates have been identified. A minimum of 13 vol % of soft inclusions embedded in an iron oxide based tribofilm is crucial for obtaining the desired properties. As long as the solid lubricants or their reaction products are softer than magnetite, the main constituent of the tribofilm, the model predicts smooth sliding and minimum wear.

  6. Brake Performance Analysis of ABS for Eddy Current and Electrohydraulic Hybrid Brake System

    Directory of Open Access Journals (Sweden)

    Ren He

    2013-01-01

    Full Text Available This paper introduces an eddy current and electro-hydraulic hybrid brake system to solve problems such as wear, thermal failure, and slow response of traditional vehicle brake system. Mathematical model was built to calculate the torque of the eddy current brake system and hydraulic brake system and analyze the braking force distribution between two types of brake systems. A fuzzy controller on personal computer based on LabVIEW and Matlab was designed and a set of hardware in the loop system was constructed to validate and analyze the performance of the hybrid brake system. Through lots of experiments on dry and wet asphalt roads, the hybrid brake system achieves perfect performance on the experimental bench, the hybrid system reduces abrasion and temperature of the brake disk, response speed is enhanced obviously, fuzzy controller keeps high utilization coefficient due to the optimal slip ratio regulation, and the total brake time has a smaller decrease than traditional hydraulic brake system.

  7. RELIABILITY ANALYSIS OF CRANE BRAKE PARAMETERS

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The high failure rate of crane brake results from improper choice of braking torque. The mathematical model of reliability for the crane brake parameters is introduced. Based on large amount of actual data the parameter reliabilities of 5~50 t general overhead travelling cranes are calculated,the probabilities that the braking torque is less than the static torque acting on the axle when the load moves down are obtained. Moreover,the ways to improve the reliability of brake parameters are discussed,the most reasonable values of braking safety coefficient are given.

  8. Stability and Transient Analysis in the Modelling of Railway Disc Brake Squeal

    OpenAIRE

    LORANG, X; CHIELLO, O

    2008-01-01

    The paper deals with friction induced vibrations and especially with railway disc brake squeal. The first part of the paper is devoted to the strategy used to model the general problem of self-excited vibrations of a rotating disc in frictional contact with two pads. Unilateral contact conditions with Coulomb friction and constant friction coefficient are considered. In order to predict the occurrence of self-excited vibrations, a classical stability analysis is performed, which consists on ...

  9. iPad portable genius

    CERN Document Server

    McFedries, Paul

    2013-01-01

    Make the most of your iPad with these savvy tips and techniques The iPad, iPad Air, and iPad mini are taking the world by storm. This no-nonsense guide covers everything you want to know to take full advantage of all your iPad has to offer. Along with necessary basics about the newest iPad; iPad Air, iPad mini; and iOS; it gives you smart; innovative ways to accomplish a variety of tasks and tips to help you maximize the convenience of your Apple digital lifestyle. More than 100 million iPads have been sold; and the number continues to growHip and practical; Portable Genius guides are packed

  10. TagPad

    DEFF Research Database (Denmark)

    Bornoe, Nis; Barkhuus, Louise

    2013-01-01

    The area of cyberinfrastructures has looked extensively at research within the natural sciences, however, the social sciences have been largely overlooked in terms of novel data collection and analysis systems. We developed a probe tool, TagPad, to look at the process for social science data...... collection through interviews and surveys. Our research participants found that TagPad facilitated structuring of interviews but we also found that the setting in which the interview takes place is essential to the success of using this particular tool. We conclude suggesting future designs of social science...

  11. Magnetic braking in ultracompact binaries

    CERN Document Server

    Farmer, Alison

    2010-01-01

    Angular momentum loss in ultracompact binaries, such as the AM Canum Venaticorum stars, is usually assumed to be due entirely to gravitational radiation. Motivated by the outflows observed in ultracompact binaries, we investigate whether magnetically coupled winds could in fact lead to substantial additional angular momentum losses. We remark that the scaling relations often invoked for the relative importance of gravitational and magnetic braking do not apply, and instead use simple non-empirical expressions for the braking rates. In order to remove significant angular momentum, the wind must be tied to field lines anchored in one of the binary's component stars; uncertainties remain as to the driving mechanism for such a wind. In the case of white dwarf accretors, we find that magnetic braking can potentially remove angular momentum on comparable or even shorter timescales than gravitational waves over a large range in orbital period. We present such a solution for the 17-minute binary AM CVn itself which a...

  12. Brakes, brake control and driver assistance systems function, regulation and components

    CERN Document Server

    2014-01-01

    Braking systems have been continuously developed and improved throughout the last years. Major milestones were the introduction of antilock braking system (ABS) and electronic stability program. This reference book provides a detailed description of braking components and how they interact in electronic braking systems. Contents Motor vehicle safety.- Basic principles of vehicle dynamics.- Car braking systems.- Car braking-system components.- Wheel brakes.- Antilock breaking systems.- Traction control system.- Electronic stability program.- Automatic brake functions.- Hydraulic modulator.- Sensors for brake control.- Sensotronic brake control.- Active steering.- Occupant protection systems.- Driver assistance systems.- Adaptive cruise control.- Parking systems.- Instrumentation.- Orientation methods.- Navigation systems.- Workshop technology. The target groups Motor-vehicle technicians in education and vocational training Master-mechanics and technicians in garage-workshops Teachers and lecturers in vocation...

  13. BRAKING OF HIGH-SPEED PASSENGER TRAINS WITH REGARD TO THE OPERATION OF AN ELECTROMAGNETIC RAIL BRAKE

    Directory of Open Access Journals (Sweden)

    N. Je. Naumenko

    2009-03-01

    Full Text Available The research of the braking process of high-speed passenger train with the use of compressed-air, electropneumatic and electromagnetic track brakes is carried out. The dependences of braking distance on motion speed for vehicles equipped by block or disk brakes as well as for a case of electromagnetic track brakes used in addition to existing braking means.

  14. 49 CFR 238.231 - Brake system.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Brake system. 238.231 Section 238.231... Equipment § 238.231 Brake system. Except as otherwise provided in this section, on or after September 9... train's primary brake system shall be capable of stopping the train with a service application from...

  15. Compact, Lightweight Servo-Controllable Brakes

    Science.gov (United States)

    Lovchik, Christopher S.; Townsend, William; Guertin, Jeffrey; Matsuoka, Yoky

    2010-01-01

    Compact, lightweight servo-controllable brakes capable of high torques are being developed for incorporation into robot joints. A brake of this type is based partly on the capstan effect of tension elements. In a brake of the type under development, a controllable intermediate state of torque is reached through on/off switching at a high frequency.

  16. Treating P.A.D.

    Science.gov (United States)

    ... Issue Past Issues Special Section Treating P.A.D. Past Issues / Summer 2008 Table of Contents For ... Illustration courtesy of NHLBI Treatment for P.A.D. is designed to reduce a patient's symptoms, prevent ...

  17. Automotive airborne brake wear debris nanoparticles and cytokinesis-block micronucleus assay in peripheral blood lymphocytes: A pilot study.

    Science.gov (United States)

    Kazimirova, Alena; Peikertova, Pavlina; Barancokova, Magdalena; Staruchova, Marta; Tulinska, Jana; Vaculik, Miroslav; Vavra, Ivo; Kukutschova, Jana; Filip, Peter; Dusinska, Maria

    2016-07-01

    Motor vehicle exhaust and non-exhaust processes play a significant role in environmental pollution, as they are a source of the finest particulate matter. Emissions from non-exhaust processes include wear-products of brakes, tires, automotive hardware, road surface, and traffic signs, but still are paid little attention to. Automotive friction composites for brake pads are composite materials which may consist of potentially hazardous materials and there is a lack of information regarding the potential influence of the brake wear debris (BWD) on the environment, especially on human health. Thus, we focused our study on the genotoxicity of the airborne fraction of BWD using a brake pad model representing an average low-metallic formulation available in the EU market. BWD was generated in the laboratory by a full-scale brake dynamometer and characterized by Raman microspectroscopy, scanning electron microscopy, and transmission electron microscopy showing that it contains nano-sized crystalline metal-based particles. Genotoxicity tested in human lymphocytes in different testing conditions showed an increase in frequencies of micronucleated binucleated cells (MNBNCs) exposed for 48h to BWD nanoparticles (NPs) (with 10% of foetal calf serum in culture medium) compared with lymphocytes exposed to medium alone, statistically significant only at the concentration 3µg/cm(2) (p=0.032). PMID:27131798

  18. Eddy current braking experiment using brake disc from aluminium series of A16061 and A17075

    International Nuclear Information System (INIS)

    The electromagnetic braking using eddy current was studied, focused on two series of aluminium as the brake disc which are A16061 and A17075. This paper presents the comparison for both series in a few varied parameters related to eddy current braking such as air-gap, number of turns and brake disc thickness. Optical tachometer has been used along with PULSE analyzer to capture the speed (rpm) and time (s). The findings shows that the smaller the air-gap, the larger of electromagnet turns and the thicker disc thickness is, will generate higher braking torque to stop the rotational motion of disc brake and give great performance for eddy current braking. Thos parameters that been evaluated also addressed a potential on expanding this knowledge to develop an electromagnetic braking system to replace the conventional braking system.

  19. EyePad

    DEFF Research Database (Denmark)

    From Jacobsen, Peter

    EyePad-projektet og denne rapport bekræfter, at tablets er blevet en vigtig faktor i hjemmets tv-stue eller hyggekrog. Selvom brugerne stadig betragter den som et stykke legetøj, der strengt taget er unødvendigt – så bliver tablets brugt i stor stil i talrige sammenhænge. Også til både nyhedstjek...... se de såkaldte ”lean back” og ”lean forward”-situationer som forholdsvis separate og afgrænsede. Enten var man i det ene eller det andet mode. Men EyePad-testen viser, at testpersonerne let kunne springe fra målrettet informationssøgning til en mere tilbagelænet læsning af en artikel, de pludselig...

  20. The trochanteric fat pad

    Directory of Open Access Journals (Sweden)

    P. Panettiere

    2011-05-01

    Full Text Available Technological developments based on the use of autologous white adipose tissue (WAT attracted attention to minor fat depots as possible sources of adipose tissue. In plastic surgery, the trochanteric fatty pad is one of the most used WAT depots for its location and organoleptic characteristics that make it particularly suitable for reconstructive procedures. Despite its wide use in clinic, the structure of this depot has never been studied in detail and it is not known if structural differences exist among trochanteric fat and other subcutaneous WAT depots. The present study was performed on trochanteric fat pad with the aim to clarify the morphology of its adipocytes, stroma and microcirculation, with particular reference to the stem niches. Histological and ultrastructural studies showed that the main peculiar feature of the trochanteric fat concerns its stromal component, which appears less dense than in the other subcutaneous WATs studied. The intra-parenchymal collagen stroma is poor and the extracellular compartment shows large spaces, filled with electron-light material, in which isolated collagen bundles are present. The adipocytes are wrapped in weak and easily detachable collagen baskets. These connective sheaths are very thin compared to the sheaths in other subcutaneous WAT depots. The capillaries are covered by large, long and thin elements surrounded by an external lamina; these perivascular cells are poor in organelles and mainly contain poly-ribosomes. In conclusion, when compared to other WAT deposits, the trochanteric fatty pad shows structural peculiarities in its stroma and microcirculation suggesting a high regenerative potential. Resistance, dissociability, microvascular weft and high regenerative potential make the trochanteric fatty pad a privileged source for harvesting in autologous WAT-based regenerative procedures.

  1. MuPAD tutorial

    CERN Document Server

    Creutzig, Christopher

    2004-01-01

    This book explains the basic use of the software package called MuPAD and gives an insight into the power of the system. MuPAD is a so-called com­ puter algebra system, which is developed mainly by Sciface Software and the MuPAD Research Group of the University of Paderborn in Germany. This introduction addresses mathematicians, engineers, computer scientists, natural scientists and, more generally, all those in need of mathematical com­ putations for their education or their profession. Generally speaking, this book addresses anybody who wants to use the power of a modern computer algebra package. There are two ways to use a computer algebra system. On the one hand, you may use the mathematical knowledge it incorporates by calling system functions interactively. For example, you can compute symbolic integrals or generate and invert matrices by calling appropriate functions. They comprise the system's mathematical intelligence and may implement sophisticated al­ gorithms. Chapters 2 through 15 discuss this...

  2. 49 CFR 230.77 - Foundation brake gear.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Foundation brake gear. 230.77 Section 230.77... Tenders Brake and Signal Equipment § 230.77 Foundation brake gear. (a) Maintenance. Foundation brake gear...) Distance above the rails. No part of the foundation brake gear of the steam locomotive or tender shall...

  3. 49 CFR 570.55 - Hydraulic brake system.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 6 2010-10-01 2010-10-01 false Hydraulic brake system. 570.55 Section 570.55... 10,000 Pounds § 570.55 Hydraulic brake system. The following requirements apply to vehicles with hydraulic brake systems. (a) Brake system failure indicator. The hydraulic brake system failure...

  4. Electromagnetic braking for Mars spacecraft

    Science.gov (United States)

    Holt, A. C.

    1986-01-01

    Aerobraking concepts are being studied to improve performance and cost effectiveness of propulsion systems for Mars landers and Mars interplanetary spacecraft. Access to megawatt power levels (nuclear power coupled to high-storage inductive or capacitive devices) on a manned Mars interplanetary spacecraft may make feasible electromagnetic braking and lift modulation techniques which were previously impractical. Using pulsed microwave and magnetic field technology, potential plasmadynamic braking and hydromagnetic lift modulation techniques have been identified. Entry corridor modulation to reduce loads and heating, to reduce vertical descent rates, and to expand horizontal and lateral landing ranges are possible benefits. In-depth studies are needed to identify specific design concepts for feasibility assessments. Standing wave/plasma sheath interaction techniques appear to be promising. The techniques may require some tailoring of spacecraft external structures and materials. In addition, rapid response guidance and control systems may require the use of structurally embedded sensors coupled to expert systems or to artificial intelligence systems.

  5. Falling Magnets and Electromagnetic Braking

    Science.gov (United States)

    Culbreath, Christopher; Palffy-Muhoray, Peter

    2009-03-01

    The slow fall of a rare earth magnet through a copper pipe is a striking example of electromagnetic braking; this remarkable phenomenon has been the subject of a number of scientific paper s [1, 2]. In a pipe having radius R and wall thickness D, the terminal velocity of the falling magnet is proportional to (R̂4)/D. It is interesting to ask what happens in the limit as D becomes very large. We report our experimental observations and theoretical predictions of the dependence of the terminal velocity on pipe radius R for large D. [1] Y. Levin, F.L. da Silveira, and F.B. Rizzato, ``Electromagnetic braking: A simple quantitative model''. American Journal of Physics, 74(9): p. 815-817 (2006). [2] J.A. Pelesko, M. Cesky, and S. Huertas, Lenz's law and dimensional analysis. American Journal of Physics, 3(1): p. 37-39. 2005.

  6. What brakes the Crab pulsar?

    Science.gov (United States)

    Čadež, A.; Zampieri, L.; Barbieri, C.; Calvani, M.; Naletto, G.; Barbieri, M.; Ponikvar, D.

    2016-03-01

    Context. Optical observations provide convincing evidence that the optical phase of the Crab pulsar follows the radio one closely. Since optical data do not depend on dispersion measure variations, they provide a robust and independent confirmation of the radio timing solution. Aims: The aim of this paper is to find a global mathematical description of Crab pulsar's phase as a function of time for the complete set of published Jodrell Bank radio ephemerides (JBE) in the period 1988-2014. Methods: We apply the mathematical techniques developed for analyzing optical observations to the analysis of JBE. We break the whole period into a series of episodes and express the phase of the pulsar in each episode as the sum of two analytical functions. The first function is the best-fitting local braking index law, and the second function represents small residuals from this law with an amplitude of only a few turns, which rapidly relaxes to the local braking index law. Results: From our analysis, we demonstrate that the power law index undergoes "instantaneous" changes at the time of observed jumps in rotational frequency (glitches). We find that the phase evolution of the Crab pulsar is dominated by a series of constant braking law episodes, with the braking index changing abruptly after each episode in the range of values between 2.1 and 2.6. Deviations from such a regular phase description behave as oscillations triggered by glitches and amount to fewer than 40 turns during the above period, in which the pulsar has made more than 2 × 1010 turns. Conclusions: Our analysis does not favor the explanation that glitches are connected to phenomena occurring in the interior of the pulsar. On the contrary, timing irregularities and changes in slow down rate seem to point to electromagnetic interaction of the pulsar with the surrounding environment.

  7. Friction Wear Property of Brake Materials by Copper-based Powder Metallurgy With Various Brake Speeds

    Institute of Scientific and Technical Information of China (English)

    LIU Jian-xiu; GAO Hong-xia; WEI Xiu-lan

    2004-01-01

    The experiment is conducted on MM-1000 friction test machine, which tests friction wear property of copper-based brake materials by powder metallurgy at different brake speeds. It shows that the coefficient of friction and wear volume are greatly influenced by brake speed. When the brake speed is 4000 r/min, which is a bit higher, the material still has a higher coefficient of friction with 0.47. When the brake speed is over 4000r/min, the coefficient of friction decreased rapidly. When the brake speed is 3000r/min, the material's wear is in its minimum. That is to say no matter how higher or lower the brake speed is the wear volume is bigger relatively. With the brake speed of the lower one it mainly refers to fatigue wear; while of higher one it mainly refers to abradant and oxidation wear.

  8. Aerodynamic investigations of ventilated brake discs.

    OpenAIRE

    Parish, D.; MacManus, David G.

    2005-01-01

    The heat dissipation and performance of a ventilated brake disc strongly depends on the aerodynamic characteristics of the flow through the rotor passages. The aim of this investigation was to provide an improved understanding of ventilated brake rotor flow phenomena, with a view to improving heat dissipation, as well as providing a measurement data set for validation of computational fluid dynamics methods. The flow fields at the exit of four different brake rotor geometrie...

  9. CFD design analysis of ventilated disc brakes

    OpenAIRE

    Pulugundla, Gautam

    2008-01-01

    This thesis reports the numerical investigation of the automotive ventilated disc brake rotor. Disc brakes operate on the principle of friction by converting kinetic energy into heat energy. The main objective of a disc brake rotor is to store this heat energy and dissipate it as soon as possible. This work is carried out in a area where there is very limited understanding. Commercial CFD code FLUENT was used for carrying out the simulations with the rotor rotating in still ...

  10. Diagnosis of heel pad injuries

    DEFF Research Database (Denmark)

    Matteoli, Sara

    load-displacement curves from in vivo heel pads. To ensure applicability also for pathological feet, the device uses force levels lower than those needed to reproduce the physiological conditions of walking. One hundred twenty seven healthy volunteers were enrolled for compression tests and ultrasound...... were conducted in two additional studies. In vivo experimental tests were used to validate a numerical 3D subject-specific heel pad model subjected to an external compression, and to further investigate the visco-elastic nature of the heel pad. Ultrasound distance measurements were compared with...... corresponding distance measurements with MRI and true values in order to assess its reliability in heel pad thickness measurements. The latter study confirmed the need to investigate the real speed of sound for the heel pad tissues, in order to obtain realistic measurements when dealing with human heel pad....

  11. iPad Made Simple

    CERN Document Server

    Trautschold, Martin; Learning, MSL Made Simple

    2010-01-01

    The new iPad is sleek, powerful, and most importantly, it's much more than just a big iPhone. Your iPad is can be used for reading, surfing the web, emailing, watching TV/Movies, getting work done, and much more. And with the upcoming wave of iPad apps, the possibilities are endless. iPad X Made Simple clarifies all of the key features on the iPad, introduces what's new, and also reveals dozens of time-saving shortcuts and techniques. The book has over 1,000 screen shots that are carefully annotated with step-by-step instructions. * Clear instructions on how to set up and use the iPad * Illust

  12. Dynamics of Braking Vehicles: From Coulomb Friction to Anti-Lock Braking Systems

    Science.gov (United States)

    Tavares, J. M.

    2009-01-01

    The dynamics of braking of wheeled vehicles is studied using the Coulomb approximation for the friction between road and wheels. The dependence of the stopping distance on the mass of the vehicle, on the number of its wheels and on the intensity of the braking torque is established. It is shown that there are two regimes of braking, with and…

  13. Cost Padding, Auditing and Collusion

    OpenAIRE

    Laffont, Jean-Jacques; Tirole, Jean

    1992-01-01

    This paper first studies how cost padding, auditing and collusion with auditors affect the power of incentive schemes in procurement and regulation. Unaudited cost padding requires fixed price contracts. Incentive schemes are more powerful under imperfect auditing than under perfect auditing and less powerful than under no auditing. The effect of collusion in auditing on the optimal power of incentive schemes is ambiguous; high-powered schemes reduce the incentive for cost padding and thus ar...

  14. An Insight to High Humidity-Caused Friction Modulation of Brake by Numerical Modeling of Dynamic Meniscus under Shearing

    OpenAIRE

    Liangbiao Chen; Gang Chen; James Chang

    2015-01-01

    To obtain an insight to high humidity-caused friction modulation in brake pad-rotor interface, the adhesion phenomenon due to a liquid bridge is simulated using an advanced particle method by varying the shearing speed of the interface. The method, called generalized interpolation material point for fluid-solid interactions (GIMP-FSI), was recently developed from the material point method (MPM) for fluid-solid interactions at small scales where surface tension dominates, thus suitable for st...

  15. Design and preliminary validation of a tool for the simulation of train braking performance

    Institute of Scientific and Technical Information of China (English)

    Luca Pugi; Monica Malvezzi; Susanna Papini; Gregorio Vettori

    2013-01-01

    Train braking performance is important for the safety and reliability of railway systems. The availability of a tool that allows evaluating such performance on the basis of the main train features can be useful for train system designers to choose proper dimensions for and optimize train’s subsystems. This paper presents a modular tool for the prediction of train braking performance, with a par-ticular attention to the accurate prediction of stopping distances. The tool takes into account different loading and operating conditions, in order to verify the safety require-ments prescribed by European technical specifications for interoperability of high-speed trains and the corresponding EN regulations. The numerical results given by the tool were verified and validated by comparison with experi-mental data, considering as benchmark case an Ansaldo EMU V250 train-a European high-speed train-currently developed for Belgium and Netherlands high-speed lines, on which technical information and experimental data directly recorded during the preliminary tests were avail-able. An accurate identification of the influence of the braking pad friction factor on braking performances allowed obtaining reliable results.

  16. Analysis and Design of Circular Plate MR Fluids Brake

    Institute of Scientific and Technical Information of China (English)

    Yang Yan; Lin Chang-Hua; Li Hui; Zhou Jing

    2004-01-01

    A magnetorheological (MR) fluids brake is a device to achieve brake by shear force of MR fluids. A MR rotary brake has the property that its braking torque changes quickly in response to an external magnetic field. In this study, the design method of the circular plate MR fluids brake is investigated theoretically. The equation of the torque transmitted by the MR fluids in the brake is derived to provide the theoretical foundation in the design of the brake. Based on this equation, after mathematically manipulated, the calculations of the volume, thickness and width of the MR fluids within the circular plate MR fluids brake are yield.

  17. Landing and Braking of Airplanes

    Science.gov (United States)

    Breguet, Louis

    1929-01-01

    In the numerical examples, we have considered an airplane landing in calm air in a fixed direction after crossing the border (with its obstacles) at a height of 30 m. Its stopping point is at a distance D from the obstacle, comprising: a distance D(sub 1) in regular gliding flight; a distance D(sub 2) in levelling off; a distance D(sub 3) in taxying on the ground. The calculations enable us to make out the following table, which gives an idea of the improvements to be expected in the use of various possible methods of braking in the air and on the ground.

  18. Understand Your Risk for PAD

    Science.gov (United States)

    ... major risk factor for PAD. Smokers may have four times the risk of PAD than nonsmokers. Our guide to quitting smoking can help you. Obesity - You can reduce your weight. People with a Body Mass Index (BMI) of 25 or higher are more likely to ...

  19. Treating P.A.D.

    Science.gov (United States)

    ... loss plan. P.A.D. Glossary Ankle-brachial index (ABI) A simple test that can be used to diagnose P.A.D. The ABI compares blood pressure in the ankle with blood pressure in the arm to see how well blood is flowing. Atherosclerosis ( ...

  20. Constraining the braking indices of magnetars

    Science.gov (United States)

    Gao, Z. F.; Li, X.-D.; Wang, N.; Yuan, J. P.; Wang, P.; Peng, Q. H.; Du, Y. J.

    2016-02-01

    Because of the lack of long-term pulsed emission in quiescence and the strong timing noise, it is impossible to directly measure the braking index n of a magnetar. Based on the estimated ages of their potentially associated supernova remnants (SNRs), we estimate the values of the mean braking indices of eight magnetars with SNRs, and find that they cluster in the range of 1-42. Five magnetars have smaller mean braking indices of 1 wind-aided braking. The larger mean braking indices of n > 3 for the other three magnetars are attributed to the decay of external braking torque, which might be caused by magnetic field decay. We estimate the possible wind luminosities for the magnetars with 1 3, within the updated magneto-thermal evolution models. Although the constrained range of the magnetars' braking indices is tentative, as a result of the uncertainties in the SNR ages due to distance uncertainties and the unknown conditions of the expanding shells, our method provides an effective way to constrain the magnetars' braking indices if the measurements of the SNR ages are reliable, which can be improved by future observations.

  1. 49 CFR 236.712 - Brake pipe.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Brake pipe. 236.712 Section 236.712 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF... OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Definitions § 236.712 Brake pipe. A...

  2. 14 CFR 27.921 - Rotor brake.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Rotor brake. 27.921 Section 27.921... STANDARDS: NORMAL CATEGORY ROTORCRAFT Powerplant Rotor Drive System § 27.921 Rotor brake. If there is a means to control the rotation of the rotor drive system independently of the engine, any limitations...

  3. 14 CFR 29.921 - Rotor brake.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Rotor brake. 29.921 Section 29.921... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Powerplant Rotor Drive System § 29.921 Rotor brake. If there is a means to control the rotation of the rotor drive system independently of the engine, any limitations...

  4. Operation peculiarities of airplane brake systems

    Directory of Open Access Journals (Sweden)

    В. Г. Докучаев

    1999-09-01

    Full Text Available Analyzed is the loading of airplane brake systems. Complex methods are proposed for investi­gation of highly loaded brake systems. The results of investigation of the influence of various factors on technical condition of friction units are given

  5. MRI of Hoffa's fat pad

    International Nuclear Information System (INIS)

    The infrapatellar fat pad of Hoffa is commonly injured but rarely discussed in the radiological literature. Abnormalities within it most commonly are the consequences of trauma and degeneration, but inflammatory and neoplastic diseases of the synovium can be confined to the fat pad. The commonest traumatic lesions follow arthroscopy, but intrinsic signal abnormalities can also be due to posterior and superior impingements syndromes and following patellar dislocation. Infrapatellar plica syndrome may also be traumatic in aetiology. The precise aetiology of ganglion cysts is not understood; the principal differential diagnosis is a meniscal or cruciate cyst. Hoffa's fat pad contains residual synovial tissue, meaning that primary neoplastic conditions of synovium may originate and be confined to the fat pad. Inflammatory changes along the posterior border of the pad may also be used to help differentiate effusion from acute synovitis on unenhanced MR examinations. (orig.)

  6. iPad Portable Genius

    CERN Document Server

    McFedries, Paul

    2010-01-01

    Everything everyone wants to know about using the Apple iPad. On January 27, 2010, Apple announced the latest in its line of revolutionary, ultraportable devices - the iPad. iPad Portable Genius is the latest in a line of ultra handy, go-to and goes-with you anywhere guides for getting the most out of a new Apple product. Written to provide readers with highly useful information that's easily accessible, iPad Portable Genius is full of tips, tricks and techniques for maximizing each of the iPad's most popular features.:; Designed in full-color with an Apple look and feel, and written in a hip,

  7. New technical solutions of using rolling stock electrodynamical braking

    Directory of Open Access Journals (Sweden)

    Leonas Povilas LINGAITIS

    2009-01-01

    Full Text Available The paper considers some theoretical and practical problems associated with the use of traction motor are operating in the generator mode (in braking. Mathematical and graphical relationships of electrodynamic braking, taking into account the requirements raised to braking systems in rail transport are presented. The latter include discontinuity of braking process, braking force regulation, depending on the locomotive speed, mass, type of railway and other parameters. Schematic diagrams of the locomotive braking and ways of controlling the braking force by varying electric circuit parameters are presented. The authors suggested contact-free regulation method of braking resistor for controlling braking force in rheostatic braking, and resistor parameters regulate with pulse regulation mode by semiconductor devices, such as new electrical components for rolling stock – IGBT transistors operating in the key mode. Presenting energy savings power systems, which are using regenerative braking-returning energy and diesel engine or any form of hybrid traction vehicles systems, circuit diagrams, electrical parameters curves.

  8. Analysis of Braking Characteristic for Tire Rotary-drum Machine%轮胎转鼓试验设备制动特性分析

    Institute of Scientific and Technical Information of China (English)

    鲍晓东; 侯勇; 张绍国

    2012-01-01

    制动系统是转鼓试验设备重要的安全部件,通过分析制动系统的材料属性,建立了制动系统的简化模型.对盘式制动器在不同制动压力下的紧急制动过程进行仿真模拟,深入分析了制动系统在不同工作负荷下制动装置摩擦表面的应力、温度场分布情况以及有效的制动时间.对比不同工况下的计算结果,得到了制动盘和刹车片的应力和温度场分布规律,并且分析了制动压力与制动时间之间的关系.结果表明制动压力越大,制动时间越短,但制动系统温升越明显,相关结论为指导设备制动系统参数的合理选定提供了理论依据.%Braking system is an important safety component for the rotating, drum test equipment, through the analysis on the material properties of the braking system, the model of braking system was es-tablishea\\Emergency braking process of the disc brake was simulated under different pressure,and then friction surface stress, temperature field distribution and effective braking time of brake system in different workload stress were further analyzedAccording to the calculation results ,stress and temperature field distribution for braking disc and pad were obtained,and relationship between braking pressure and braking time was analyzed.The results show that as the braking pressure enhanced, the braking time is shorter,however, the temperature rise for braking system is more obvious.Conclusion provides a theoretical basis for brake system rational parameter selection.

  9. Evaluation of the fate and pathological response in the lung and pleura of brake dust alone and in combination with added chrysotile compared to crocidolite asbestos following short-term inhalation exposure

    International Nuclear Information System (INIS)

    This study was designed to provide an understanding of the biokinetics and potential toxicology in the lung and pleura following inhalation of brake dust following short term exposure in rats. The deposition, translocation and pathological response of brake-dust derived from brake pads manufactured with chrysotile were evaluated in comparison to the amphibole, crocidolite asbestos. Rats were exposed by inhalation 6 h/day for 5 days to either brake-dust obtained by sanding of brake-drums manufactured with chrysotile, a mixture of chrysotile and the brake-dust or crocidolite asbestos. The chrysotile fibers were relatively biosoluble whereas the crocidolite asbestos fibers persisted through the life-time of the animal. This was reflected in the lung and the pleura where no significant pathological response was observed at any time point in the brake dust or chrysotile/brake dust exposure groups through 365 days post exposure. In contrast, crocidolite asbestos produced a rapid inflammatory response in the lung parenchyma and the pleura, inducing a significant increase in fibrotic response in both of these compartments. Crocidolite fibers were observed embedded in the diaphragm with activated mesothelial cells immediately after cessation of exposure. While no chrysotile fibers were found in the mediastinal lymph nodes, crocidolite fibers of up to 35 μm were observed. These results provide support that brake-dust derived from chrysotile containing brake drums would not initiate a pathological response in the lung or the pleural cavity following short term inhalation. - Highlights: • Evaluated brake dust w/wo added chrysotile in comparison to crocidolite asbestos. • Persistence, translocation, pathological response in the lung and pleural cavity. • Chrysotile cleared rapidly from the lung while the crocidolite asbestos persisted. • No significant pathology in lung or pleural cavity observed at any time point in the brake-dust groups. • Crocidolite quickly

  10. Evaluation of the fate and pathological response in the lung and pleura of brake dust alone and in combination with added chrysotile compared to crocidolite asbestos following short-term inhalation exposure

    Energy Technology Data Exchange (ETDEWEB)

    Bernstein, D.M., E-mail: davidb@itox.ch [Consultant in Toxicology, Geneva (Switzerland); Rogers, R.A., E-mail: rarogers5@yahoo.com [Rogers Imaging, Needham, MA (United States); Sepulveda, R. [Rogers Imaging, Needham, MA (United States); Kunzendorf, P., E-mail: Peter.Kunzendorf@GSA-Ratingen.de [GSA Gesellschaft für Schadstoffanalytik mbH, Ratingen (Germany); Bellmann, B. [Fraunhofer Institute for Toxicology and Experimental Medicine, Hannover (Germany); Ernst, H., E-mail: Heinrich.ernst@item.fraunhofer.de [Fraunhofer Institute for Toxicology and Experimental Medicine, Hannover (Germany); Creutzenberg, O. [Fraunhofer Institute for Toxicology and Experimental Medicine, Hannover (Germany); Phillips, J.I., E-mail: jim.phillips@nioh.nhls.ac.za [National Institute for Occupational Health, National Health Laboratory Service, Johannesburg South Africa and Department of Biomedical Technology, Faculty of Health Sciences, University of Johannesburg, Johannesburg (South Africa)

    2015-02-15

    This study was designed to provide an understanding of the biokinetics and potential toxicology in the lung and pleura following inhalation of brake dust following short term exposure in rats. The deposition, translocation and pathological response of brake-dust derived from brake pads manufactured with chrysotile were evaluated in comparison to the amphibole, crocidolite asbestos. Rats were exposed by inhalation 6 h/day for 5 days to either brake-dust obtained by sanding of brake-drums manufactured with chrysotile, a mixture of chrysotile and the brake-dust or crocidolite asbestos. The chrysotile fibers were relatively biosoluble whereas the crocidolite asbestos fibers persisted through the life-time of the animal. This was reflected in the lung and the pleura where no significant pathological response was observed at any time point in the brake dust or chrysotile/brake dust exposure groups through 365 days post exposure. In contrast, crocidolite asbestos produced a rapid inflammatory response in the lung parenchyma and the pleura, inducing a significant increase in fibrotic response in both of these compartments. Crocidolite fibers were observed embedded in the diaphragm with activated mesothelial cells immediately after cessation of exposure. While no chrysotile fibers were found in the mediastinal lymph nodes, crocidolite fibers of up to 35 μm were observed. These results provide support that brake-dust derived from chrysotile containing brake drums would not initiate a pathological response in the lung or the pleural cavity following short term inhalation. - Highlights: • Evaluated brake dust w/wo added chrysotile in comparison to crocidolite asbestos. • Persistence, translocation, pathological response in the lung and pleural cavity. • Chrysotile cleared rapidly from the lung while the crocidolite asbestos persisted. • No significant pathology in lung or pleural cavity observed at any time point in the brake-dust groups. • Crocidolite quickly

  11. What brakes the Crab pulsar?

    CERN Document Server

    Čadež, A; Barbieri, C; Calvani, M; Naletto, G; Barbieri, M; Ponikvar, D

    2015-01-01

    Optical observations provide convincing evidence that the optical phase of the Crab pulsar follows the radio one closely. Since optical data do not depend on dispersion measure variations, they provide a robust and independent confirmation of the radio timing solution. The aim of this paper is to find a global mathematical description of Crab pulsar's phase as a function of time for the complete set of published Jodrell Bank radio ephemerides (JBE) in the period 1988-2014. We apply the mathematical techniques developed for analyzing optical observations to the analysis of JBE. We break the whole period into a series of episodes and express the phase of the pulsar in each episode as the sum of two analytical functions. The first function is the best-fitting local braking index law, and the second function represents small residuals from this law with an amplitude of only a few turns, which rapidly relaxes to the local braking index law. From our analysis, we demonstrate that the power law index undergoes "inst...

  12. Diesel Technology: Brakes. Teacher Edition [and] Student Edition.

    Science.gov (United States)

    Hilley, Robert; Scarberry, Terry; Kellum, Mary

    This document contains teacher and student materials for a course on brakes in the diesel technology curriculum. The course consists of 12 units organized in three sections. The three units of the introductory section cover: (1) brakes; (2) wheel bearings and seals; and (3) antilock brake systems. The second section, Hydraulic Brakes, contains the…

  13. Nonlinear Coupling Characteristics Analysis of Integrated System of Electromagnetic Brake and Frictional Brake of Car

    Directory of Open Access Journals (Sweden)

    Ren He

    2015-01-01

    Full Text Available Since theoretical guidance is lacking in the design and control of the integrated system of electromagnetic brake and frictional brake, this paper aims to solve this problem and explores the nonlinear coupling characteristics and dynamic characteristics of the integrated system of electromagnetic brake and frictional brake. This paper uses the power bond graph method to establish nonlinear coupling mathematical model of the integrated system of electromagnetic brake and frictional brake and conducts the contrastive analysis on the dynamic characteristics based on this mathematical model. Meanwhile, the accuracy of the nonlinear coupling mathematical model proposed above is verified on the hardware in the loop simulation platform, and nonlinear coupling characteristics of the integrated system are also analyzed through experiments.

  14. The influence of various pressures in pneumatic tyre on braking process of car with anti-lock braking system

    Directory of Open Access Journals (Sweden)

    Damian HADRYŚ

    2008-01-01

    Full Text Available In this article has been presented the influence of various pressures inpneumatic tyre of passenger car Fiat Panda 1.3 JTD with anti-lock braking system on chosen parameters of braking process: course of braking deceleration, maximum value of deceleration, braking distances.

  15. Screw-released roller brake

    Science.gov (United States)

    Vranish, John M. (Inventor)

    1999-01-01

    A screw-released roller brake including an input drive assembly, an output drive assembly, a plurality of locking sprags, a mechanical tripper nut for unlocking the sprags, and a casing therefor. The sprags consist of three dimensional (3-D) sprag members having pairs of contact surface regions which engage respective pairs of contact surface regions included in angular grooves or slots formed in the casing and the output drive assembly. The sprags operate to lock the output drive assembly to the casing to prevent rotation thereof in an idle mode of operation. In a drive mode of operation, the tripper is either self actuated or motor driven and is translated linearly up and down against a spline and at the limit of its travel rotates the sprags which unlock while coupling the input drive assembly to the output drive assembly so as to impart a turning motion thereto in either a clockwise or counterclockwise direction.

  16. iPad Fully Loaded

    CERN Document Server

    Hess, Alan

    2011-01-01

    Alan knows-and he's telling! All about your iPad. It's an iPod. It's an e-reader. It's an instant classic. And now you can discover all the secrets to this dazzling device, thanks to Alan Hess. You may think you already know your iPad inside and out, until Alan shows you how to write your own books, stream your iTunes, view comic book files, and transfer photos with Eye-Fi. He provides all the tips and techniques you need to get the absolute most out of your iPad. Figure you already get all things iPad? Don't count on it-until you read this book! Browse through the iBooksStore and start speed

  17. iPad For Dummies

    CERN Document Server

    Baig, Edward C

    2011-01-01

    Your world is just a touch away with your iPad! The iPad combines the best of your favorite gadgets into one amazing, ultraportable touch device. This handy guide helps you figure out all the basics - from sending e-mail and surfing the web to playing games, recording and watching videos, sharing photos, making FaceTime video calls, downloading cool apps, and more. Whatever you want your iPad to do, the fun begins right here. Open the book and find: Steps for getting started with your iPad How to make a video call with FaceTime Tips for downloading content from iTunes, the App Store, and the i

  18. An Intelligent Regenerative Braking Strategy for Electric Vehicles

    OpenAIRE

    Zhibin Song; Weimin Li; Guoqing Xu; Kun Xu

    2011-01-01

    Regenerative braking is an effective approach for electric vehicles (EVs) to extend their driving range. A fuzzy-logic-based regenerative braking strategy (RBS) integrated with series regenerative braking is developed in this paper to advance the level of energy-savings. From the viewpoint of securing car stability in braking operations, the braking force distribution between the front and rear wheels so as to accord with the ideal distribution curve are considered to prevent vehicles from ex...

  19. An Intelligent Regenerative Braking Strategy for Electric Vehicles

    OpenAIRE

    Guoqing Xu; Weimin Li; Kun Xu; Zhibin Song

    2011-01-01

    Regenerative braking is an effective approach for electric vehicles (EVs) to extend their driving range. A fuzzy-logic-based regenerative braking strategy (RBS) integrated with series regenerative braking is developed in this paper to advance the level of energy-savings. From the viewpoint of securing car stability in braking operations, the braking force distribution between the front and rear wheels so as to accord with the ideal distribution curve are considered to prevent vehicles from ex...

  20. Properties of Micromegas pad detectors

    International Nuclear Information System (INIS)

    Micromegas detectors with a resistive strip layout are well suited to measure particle tracks in high rate environments. However, classical Micromegas with a 2D strip readout structure can lead to ambiguities in the track reconstruction. This problem can be solved by adding an additional Micromegas layer with a pad readout structure. In this talk first results obtained with a 10 x 10 cm2 Micromegas detector with 500 pads are presented. Two different layouts are compared and discussed.

  1. Studies of Vehicular Padding Materials

    OpenAIRE

    Sances, Anthony; Carlin, Fred H.; Herbst, Brian; Forrest, Steve; Meyer, Steve; Khadilkar, Anil; Friedman, Keith; Bish, Jack

    2000-01-01

    The Federal Motor Vehicle Safety Standard 571.201 discusses occupant protection with interior impacts of vehicles. Rule making by the National Highway Traffic Safety Administration (NHTSA) has identified padding for potential injury reduction in vehicles. In these studies, head injury mitigation with padding on vehicular roll bars and brush bars was evaluated. Studies were conducted with free falling Hybrid 50% male head form drops on the fore head and side of the head and a 5% female head. M...

  2. Dynamics of braking vehicles: from Coulomb friction to anti-lock braking systems

    International Nuclear Information System (INIS)

    The dynamics of braking of wheeled vehicles is studied using the Coulomb approximation for the friction between road and wheels. The dependence of the stopping distance on the mass of the vehicle, on the number of its wheels and on the intensity of the braking torque is established. It is shown that there are two regimes of braking, with and without sliding. The advantage of using an anti-lock braking system (ABS) is put in evidence, and a quantitative estimate of its efficiency is proposed and discussed

  3. Hunting Plan Morgan Brake National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This plan provides guidelines for administration of hunting activity and for development, maintenance, and enforcement of regulations and guidelines on Morgan Brake...

  4. Method and apparatus for wind turbine braking

    Science.gov (United States)

    Barbu, Corneliu; Teichmann, Ralph; Avagliano, Aaron; Kammer, Leonardo Cesar; Pierce, Kirk Gee; Pesetsky, David Samuel; Gauchel, Peter

    2009-02-10

    A method for braking a wind turbine including at least one rotor blade coupled to a rotor. The method includes selectively controlling an angle of pitch of the at least one rotor blade with respect to a wind direction based on a design parameter of a component of the wind turbine to facilitate reducing a force induced into the wind turbine component as a result of braking.

  5. Constraining the Braking Indices of Magnetars

    CERN Document Server

    Gao, Z F; Wang, N; Yuan, J P; Peng, Q H; Du, Y J

    2015-01-01

    Due to the lack of long term pulsed emission in quiescence and the strong timing noise, it is impossible to directly measure the braking index $n$ of a magnetar. Based on the estimated ages of their potentially associated supernova remnants (SNRs), we estimate the values of $n$ of nine magnetars with SNRs, and find that they cluster in a range of $1\\sim$41. Six magnetars have smaller braking indices of $13$ for other three magnetars are attributed to the decay of external braking torque, which might be caused by magnetic field decay. We estimate the possible wind luminosities for the magnetars with $13$ within the updated magneto-thermal evolution models. We point out that there could be some connections between the magnetar's anti-glitch event and its braking index, and the magnitude of $n$ should be taken into account when explaining the event. Although the constrained range of the magnetars' braking indices is tentative, our method provides an effective way to constrain the magnetars' braking indices if th...

  6. Topology Optimization in Automotive Brake Pedal Redesign

    Directory of Open Access Journals (Sweden)

    Mohd Nizam Sudin

    2014-03-01

    Full Text Available Nowadays, automotive industry is continuing to strive for light weight vehicle in improving fuel efficiency and emissions reduction. To produce a better performance car it is important to design vehicles with optimum weight. In order to reduce the weight of vehicle without sacrificing its integrity, this project aims to employ topology optimization technique to propose an optimal design of an automotive component in early phase of product development. In this project the material used for an existing brake pedal is unchanged as this study focuses on reducing weight of existing brake pedal without material substitution. The digital model of an existing brake pedal was generated using CATIA V5 solid modelling software. Topology optimization was performed by using Altair Optistruct software under linear static stress analysis. Finally, a new light weight design brake pedal is proposed. The result of the study shows that the weight of a new designed brake pedal was 22% less as compared to an existing brake pedal without sacrificing its performance requirement.

  7. Automated visual inspection of brake shoe wear

    Science.gov (United States)

    Lu, Shengfang; Liu, Zhen; Nan, Guo; Zhang, Guangjun

    2015-10-01

    With the rapid development of high-speed railway, the automated fault inspection is necessary to ensure train's operation safety. Visual technology is paid more attention in trouble detection and maintenance. For a linear CCD camera, Image alignment is the first step in fault detection. To increase the speed of image processing, an improved scale invariant feature transform (SIFT) method is presented. The image is divided into multiple levels of different resolution. Then, we do not stop to extract the feature from the lowest resolution to the highest level until we get sufficient SIFT key points. At that level, the image is registered and aligned quickly. In the stage of inspection, we devote our efforts to finding the trouble of brake shoe, which is one of the key components in brake system on electrical multiple units train (EMU). Its pre-warning on wear limitation is very important in fault detection. In this paper, we propose an automatic inspection approach to detect the fault of brake shoe. Firstly, we use multi-resolution pyramid template matching technology to fast locate the brake shoe. Then, we employ Hough transform to detect the circles of bolts in brake region. Due to the rigid characteristic of structure, we can identify whether the brake shoe has a fault. The experiments demonstrate that the way we propose has a good performance, and can meet the need of practical applications.

  8. Geometric optimal design of a magneto-rheological brake considering different shapes for the brake envelope

    International Nuclear Information System (INIS)

    When designing a magneto-rheological brake (MRB), it is well known that the shape of the brake envelope significantly affects the performance characteristics of the brake. In this study, different shapes for the MR brake envelope, such as rectangular, polygonal or spline shape, are considered and the most suitable shape identified. MRBs with different envelope shapes are introduced followed by the derivation of the braking torque based on Bingham-plastic behavior of the magneto-rheological fluid (MRF). Optimization of the design of the MRB with different envelope shapes is then done. The optimization problem is to find the optimal value for the significant geometric dimensions of the MRB that can produce a certain required braking torque while the brake mass is minimized. A finite element analysis integrated with an optimization tool is employed to obtain optimal solutions for the MRBs. From the results, the most suitable shape for the brake envelope is identified and discussed with the reduction of mass. In addition, the results of the analysis are compared with the experimental results to verify the proposed optimal design characteristics. (paper)

  9. The PHOBOS silicon pad sensors

    International Nuclear Information System (INIS)

    PHOBOS is one of the four experiments at the Relativistic Heavy Ion Collider at Brookhaven National Laboratory. PHOBOS utilizes silicon sensors to measure charged particle multiplicity distributions and to track particles in a 2-arm spectrometer. The detector consists of 450 silicon pad sensors. Nine different pad geometries are used to match the different physics needs of the experiment. A relatively high granularity, of up to 1536 channels per sensor, is used in the spectrometer. The multiplicity detector uses 128 and 64 channel sensors and the charge deposition per pad is measured to determine the multiplicity of single events. All sensors are of the double-metal silicon pad type with pad sizes from 1 up to 4 cm2. They are produced in Taiwan by the ERSO foundry under supervision of Miracle Co. and National Central University. An extensive testing procedure makes it possible to select sensors suited for use in PHOBOS. Detector modules consisting of up to 5 sensors are read out with integrated chips of either 64 or 128 channels. The test results of the sensors and the performance of the assembled detector modules are discussed

  10. Braking Index of Isolated Pulsars

    CERN Document Server

    Hamil, Oliver Q; Urbanec, Martin; Urbancova, Gabriela

    2016-01-01

    Isolated pulsars are rotating neutron stars with accurately measured angular velocities $\\Omega$, and their time derivatives that show unambiguously that the pulsars are slowing down. The commonly accepted view is that it arises through emission of magnetic dipole radiation (MDR) from a rotating magnetized body. The calculated energy loss by a rotating pulsar with a constant moment of inertia is assumed proportional to a model dependent power of $\\Omega$. This relation leads to the power law $\\dot{\\Omega}$ = -K $\\Omega^{\\rm n}$ where $n$ is called the braking index. The MDR model predicts $n$ exactly equal to 3. Selected observations of isolated pulsars provide rather precise values of $n$, individually accurate to a few percent or better, in the range 1$ <$ n $ < $ 2.8, which is consistently less than the predictions of the MDR model. In spite of an extensive investigation of various modifications of the MDR model, no satisfactory explanation of observation has been found yet. The aim of this work is t...

  11. Neutrons put the brakes on stress

    International Nuclear Information System (INIS)

    Don't you hate it when you're driving along, put your foot on the brake and feel that juddering feeling through the pedal? It happens when the disc brake rotors become distorted through normal use of the brakes. To the car manufacturing industry it's called runout, and is a multimillion dollar warranty problem each year. Not to mention a pain for drivers! Dr Maurice Ripley and Dr Oliver Kirstein from the Australian Nuclear Science and Technology Organisation (ANSTO) wanted to figure out whether runout is caused by residual stresses from the manufacturing process or by normal use of the brake, so they decided to test and compare a used and new brake disc. 'To picture what metal looks like at the atomic level, imagine spheres stacked evenly around each other in all three dimensions,' explained Kirstein. The spheres represent atoms in the metal and the structure is called a metallic lattice.' We're familiar with the idea that metal expands when it gets hot - the atoms get excited with the heat and have the energy to move further away from each other, so spaces between the atoms in the lattice get larger. 'When parts of the metal are heated up and cool down at different rates, you may end up with a distorted lattice with some parts expanded and others not,' explained Kirstein. 'This unevenness in the lattice creates residual stress.' While a bunch of methods were available to test the discs, Kirstein and Ripley picked neutrons from ANSTO's HIFAR (High Flux Australian Reactor) as their tool of choice. 'Neutrons allow us to look at the inside of the metal without damaging it,' said Kirstein. 'They can penetrate through the iron, so we were able to take measurements at a series of points at different depths through the brake disc.' Word around the car industry is that when residual stresses are relaxed through heating of the brake disc during use, the discs could potentially distort, causing the runout and that juddering feeling. But everyone was clueless as to what

  12. An Insight to High Humidity-Caused Friction Modulation of Brake by Numerical Modeling of Dynamic Meniscus under Shearing

    Directory of Open Access Journals (Sweden)

    Liangbiao Chen

    2015-05-01

    Full Text Available To obtain an insight to high humidity-caused friction modulation in brake pad-rotor interface, the adhesion phenomenon due to a liquid bridge is simulated using an advanced particle method by varying the shearing speed of the interface. The method, called generalized interpolation material point for fluid-solid interactions (GIMP-FSI, was recently developed from the material point method (MPM for fluid-solid interactions at small scales where surface tension dominates, thus suitable for studying the partially wet brake friction due to high humidity at a scale of 10 m. Dynamic capillary effects due to surface tension and contact angles are simulated. Adhesion forces calculated by GIMP-FSI are consistent with those from the existing approximate meniscus models. Moreover, the numerical results show that capillary effects induce modulations of adhesion as slip speed changes. In particular, the adhesion modulation could be above 30% at low speed. This finding provides insights into how the high humidity-caused friction could cause modulations of brake, which are unable to be achieved by conventional models. Therefore, the numerical analysis helps to elucidate the complex friction mechanisms associated with brakes that are exposed to high humidity environments.

  13. 77 FR 51649 - Federal Motor Vehicle Safety Standards; Motorcycle Brake Systems

    Science.gov (United States)

    2012-08-24

    .... Wet Brake Test E. Heat Fade Test F. Parking Brake System Test G. Antilock Brake System (ABS.... Other ABS-Related Comments H. Partial Failure Test--Split Service Brake System I. Power-Assisted Braking..., Motorcycle Brake Systems, Notice of Proposed Rulemaking, 73 FR 54020 (Sept. 17, 2008) (hereinafter ``FMVSS...

  14. Brake force estimation for electromechanical vehicle brakes; Bremskraft-Rekonstruktion fuer elektromechanische Fahrzeugbremsen

    Energy Technology Data Exchange (ETDEWEB)

    Schwarz, R. [Continental Teves (Germany)

    1999-06-01

    Due to the increasing safety and comfort demands of the customer, the functionality of modern brake systems has grown continuously in the last years. However, implementation of the extended functionality in conventional brake hydraulics makes active electronic intervention necessary and therefore requires a lot of technical effort. In recent years the automotive supplier industry has started to develop brake systems which have electromechanical brake actuators generating the brake forces at the individual wheels. Electromechanically actuated wheel brakes need to be operated in a closed control loop. This paper introduces a new method to reconstruct the needed feedback value brake force from easy to measure signals. (orig.) [Deutsch] Aufgrund des gestiegenen Sicherheits- und Komfortbewusstseins der Fahrzeugkaeufer ist die Funktionsvielfalt moderner Bremssysteme in den letzten Jahren staendig gewachsen. Die Umsetzung der erweiterten Funktionalitaet mittels konventioneller Bremsenhydraulik ist jedoch durch den elektronischen, aktiven Eingriff sehr aufwendig. In den letzten Jahren hat daher die Automobilzulieferindustrie begonnen, Bremssysteme zu entwickeln, bei denen die Bremskraft an den einzelnen Raedern von elektromechanischen Bremsaktuatoren aufgebracht wird. Elektromechanisch betaetigte Radbremsen muessen im geschlossenen Regelkreis betrieben werden. Der vorliegende Beitrag, der im Rahmen einer Forschungskooperation zwischen Continental Teves und dem Institut fuer Automatisierungstechnik der TU Darmstadt entstand stellt ein Verfahren vor, mit dem die dafuer benoetigte Rueckfuehrungsgroesse `Bremskraft` aus einfach messbaren Signalen rekonstruiert werden kann. (orig.)

  15. Hump behind the shoulders (Dorsocervical fat pad)

    Science.gov (United States)

    Buffalo hump; Dorsocervical fat pad ... Cause of dorsocervical fat pad includes any of the following: Certain medicines used to treat HIV or AIDS Long-term use of certain glucocorticoid medicines, ...

  16. ACTIVE FRONT STEERING DURING BRAKING PROCESS

    Institute of Scientific and Technical Information of China (English)

    CHEN Deling; CHEN Li; YIN Chengliang; ZHANG Yong

    2008-01-01

    An active front steering (AFS) intervention control during braking for vehicle stability is presented. Based on the investigation of AFS mechanism, a simplified model of steering system is established and integrated with vehicle model. Then the AFS control on vehicle handling dynamics during braking is designed. Due to the difficulties associated with the sideslip angle measurement of vehicle, a state observer is designed to provide real time estimation. Thereafter, the controller with the feedback of both sideslip and yaw angle is implemented. To evaluate the system control, the proposed AFS controlled vehicle has been tested in the Hardware-in-the-loop-simulation (HILS) system and compared with that of conventional vehicle. Results show that AFS can improve vehicle lateral stability effectively without reducing the braking performance.

  17. A Review of a Study on Disc Brake Noise

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    With the development of the automotive industry, disc brake noise has become an issue of growing concern to the automotive industry and customers. In this paper, the types of disc brake noise have been discussed. Ajter that, the theories and models that have been proposed as an explanation of brake squeal are reviewed. On the basis of these theories and models, some example simulations of disc brake squeal which use the Finite Element method and mathematical model have been introduced.

  18. Hillside, Morgans Brake, and Mathews Brake National Wildlife Refuges Deer Harvest Records are from 2008 and 2014

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — These harvest data are from Hillside, Morgans Brake, and Mathews Brake NWRs during the 2008 and 2014 deer seasons. They measure weight, antler size, prevalence of...

  19. Biweekly Waterfowl Counts from Mathews Brake, Morgan Brake, and Hillside National Wildlife Refuges in 2001 and 2002

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Biweekly Waterfowl Counts from Mathews Brake, Morgan Brake, and Hillside National Wildlife Refuges conducted from October 2001 to February 2002

  20. Central Mississippi Refuges: Yazoo, Panther Swamp, Hillside, Morgan Brake & Bathews Brake: Annual narrative report: Calendar year 2001

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Yazoo, Hillside, Panther Swamp, Morgan Brake, and Mathews Brake NWRs covers refuge activities during 2001. The report begins with a...

  1. 30 CFR 75.1404 - Automatic brakes; speed reduction gear.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Automatic brakes; speed reduction gear. 75.1404... Automatic brakes; speed reduction gear. Each locomotive and haulage car used in an underground coal mine... brakes, locomotives and haulage cars shall be subject to speed reduction gear, or other similar...

  2. 49 CFR 238.319 - Running brake test.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Running brake test. 238.319 Section 238.319... Requirements for Tier I Passenger Equipment § 238.319 Running brake test. (a) As soon as conditions safely permit, a running brake test shall be performed on each passenger train after the train has received,...

  3. The braking indices in pulsar emission models

    CERN Document Server

    Wu, F; Gil, J; Gil, Janusz

    2003-01-01

    Using the method proposed in a previous paper, we calculate pulsar braking indices in the models with torque contributions from both inner and outer accelerating regions, assuming that the interaction between them is negligible. We suggest that it is likely that the inverse Compton scattering induced polar vacuum gap and the outer gap coexist in the pulsar magnetosphere. We include the new near threshold vacuum gap models with curvature-radiation and inverse Compton scattering induced cascades, respectively; and find that these models can well reproduce the measured values of the braking indices.

  4. Peripheral Arterial Disease (P.A.D.)

    Science.gov (United States)

    ... turn Javascript on. Peripheral Artery Disease (P.A.D.) What is P.A.D.? Arteries Clogged With Plaque Peripheral arterial disease (P. ... button on your keyboard.) Why Is P.A.D. Dangerous? Click for more information Blocked blood flow ...

  5. Hillside, Morgan Brake, and Mathews Brake National Wildlife Refuges Reforestation Plan for 1992-1996

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This plan addresses the history of reforestation at Hillside National Wildlife Refuge and its two satellite refuges, Morgan Brake National Wildlife Refuge and...

  6. Study on reduction method of brake squeal; Brake naki teigen shuho ni kansuru kento

    Energy Technology Data Exchange (ETDEWEB)

    Nakajima, T.; Okada, Y. [Aisin Seiki Co. Ltd., Aichi (Japan)

    1997-10-01

    The reduction of brake squeal is an important technological subject in terms of making vehicles quieter. In our research, we carried out a modal analysis from the caliper to the installation bracket during generating brake squeal to identify the places that influence the squeal. Based on this, we studied proposals to reduce the squeal, and have reduced the squeal noise at about 5 kHz as reported in this paper. 1 ref., 12 figs.

  7. Research on Rotating Permanent Magnet Eddy Current Brake%旋转型永磁涡流制动装置的研究

    Institute of Scientific and Technical Information of China (English)

    倪文波; 赵科; 王雪梅; 蒋冬青; 李芾

    2011-01-01

    This paper studied the non-friction rotating permanent magnet eddy current brake technique, which was used on nonpowered vehicles. Based on the theory of eddy current brake, the rotating permanent magnet eddy current brake was designed according to the structure of CRH2 EMU's trailer bogie. The dynamic analyses of rotating permanent magnet eddy current brake was made by ANSYS,the brake's power at different speeds was calculated. At different numbers of pole pairs, circumferential distances of the pole, thickness of pole pad and gap widths of rotating permanent magnet eddy current brake, the running resistances caused by leakage of magnet field were analyzed.The conclusions got from this article provide some theory foundations for application of the rotation eddy current brake.%研究了一种适用于非动力车辆的非摩擦制动技术--旋转型永磁涡流技术.根据涡流制动原理,以CRH2拖车转向架为对象,设计了旋转型永磁涡流制动装置.运用ANSYS软件着重进行了旋转型水磁涡流制动装置磁场的瞬态分析,得到在不同速度下感应盘所能提供的制动功率.最后从制动装置的永磁体磁极埘数、磁极周向距离、极片厚度、空隙宽度等方而对漏磁造成的运行阻力进行了分析,并提出相应的措施.

  8. Wear determination in braking systems by radioisotopes

    International Nuclear Information System (INIS)

    Friction and wear behaviour of friction couples has been tested applying loads and sliding speeds. The determination was carried out by direct measurements of the lining material and by surface activation of the opposite material with protons. The application limits of several braking materials could be determined and compared

  9. Massive star models with magnetic braking

    CERN Document Server

    Meynet, Georges; Maeder, Andre

    2010-01-01

    Magnetic fields at the surface of a few early-type stars have been directly detected. These fields have magnitudes between a few hundred G up to a few kG. In one case, evidence of magnetic braking has been found. We investigate the effects of magnetic braking on the evolution of rotating ($\\upsilon_{\\rm ini}$=200 km s$^{-1}$) 10 M$_\\odot$ stellar models at solar metallicity during the main-sequence (MS) phase. The magnetic braking process is included in our stellar models according to the formalism deduced from 2D MHD simulations of magnetic wind confinement by ud-Doula and co-workers. Various assumptions are made regarding both the magnitude of the magnetic field and of the efficiency of the angular momentum transport mechanisms in the stellar interior. When magnetic braking occurs in models with differential rotation, a strong and rapid mixing is obtained at the surface accompanied by a rapid decrease in the surface velocity. Such a process might account for some MS stars showing strong mixing and low surfa...

  10. Electric disc brakes hold nuclear aircraft carriers

    International Nuclear Information System (INIS)

    Two nuclear-powered aircraft carriers, the U.S.S. Nimitz and the soon-to-be-completed U.S.S. Dwight D. Eisenhower, use electric disc brakes to stop and hold lines on warping and mooring capstans during docking maneuvers and mooring operations

  11. Asbestos free friction composition for brake linings

    Indian Academy of Sciences (India)

    Arnab Ganguly; Raji George

    2008-02-01

    An asbestos free friction material composite for brake linings is synthesized containing fibrous reinforcing constituents, friction imparting and controlling additives, elastomeric additives, fire retarding components and a thermosetting resin. The composite shows exemplary friction characteristics and has great resistance to wear and shows good temperature stability.

  12. Innovation of Electromagnetic Brake for Rail Vehicles

    Czech Academy of Sciences Publication Activity Database

    Ulrych, B.; Doležel, Ivo

    Opole : Technical University of Opole, 2005, s. 650-653. ISBN 83-88492-74-8. [International Symposium on Electrical Machines SME 2005 /41./. Opole-Jarnoltówek (PL), 14.06.2005-17.06.2005] Institutional research plan: CEZ:AV0Z20570509 Keywords : electromagnetic brake * electromagnetic field * numerical analysis Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering

  13. STS-120 on Launch Pad

    Science.gov (United States)

    2007-01-01

    A photographer used a fisheye lens attached to an electronic still camera to record a series of photos of the Space Shuttle Discovery at the launch pad while the STS-120 crew was at Kennedy Space Center for the Terminal Countdown Demonstration Test in October 2007. The STS-120 mission launched from Kennedy Space Center's launch pad 39A at 11:38:19 a.m. (EDT) on October 23, 2007. The crew included Scott E. Parazynski, Douglas H. Wheelock, Stephanie D. Wilson, all mission specialists; George D. Zamka, pilot; Pamela A. Melroy, commander; Daniel M. Tani, Expedition 16 flight engineer; and Paolo A. Nespoli, mission specialist representing the European Space Agency (ESA). Major objectives included the installation of the P6 solar array of the port truss and delivery and installment of Harmony, the Italian-built U.S. Node 2 on the International Space Station (ISS).

  14. Comparative Frictional Analysis of Automobile Drum and Disc Brakes

    Directory of Open Access Journals (Sweden)

    H.P. Khairnar

    2016-03-01

    Full Text Available In the present work, a comparative frictional behaviour of drum brakes and disc brakes in automobiles has been investigated. The influential factors; contact force and friction radius were modeled for the estimation of the friction coefficient for drum as well as disc brakes. The effect of contact force and friction radius is studied with varying conditions of parameters; longitudinal force, caliper force and torque on piston side as well as non-piston side. The numerical results obtained have been compared with the similar obtained from virtual Matlab/Simulink models for drum and disc brakes. The results evidenced that friction radius predominantly affects brake pressure and thus the friction coefficient, also the increase in contact force resulted with decrease in friction coefficient both for drum and disc brakes. Further it has been found that disc brakes exhibit gradual decrease of friction coefficient due to the equitable distribution of braking effort while drum brake presents sudden variations in friction coefficient. It can be revealed that frictional behaviour of disc brake is more consistent than drum brake.

  15. Pedestrian injury mitigation by autonomous braking.

    Science.gov (United States)

    Rosén, Erik; Källhammer, Jan-Erik; Eriksson, Dick; Nentwich, Matthias; Fredriksson, Rikard; Smith, Kip

    2010-11-01

    The objective of this study was to calculate the potential effectiveness of a pedestrian injury mitigation system that autonomously brakes the car prior to impact. The effectiveness was measured by the reduction of fatally and severely injured pedestrians. The database from the German In-Depth Accident Study (GIDAS) was queried for pedestrians hit by the front of cars from 1999 to 2007. Case by case information on vehicle and pedestrian velocities and trajectories were analysed to estimate the field of view needed for a vehicle-based sensor to detect the pedestrians one second prior to the crash. The pre-impact braking system was assumed to activate the brakes one second prior to crash and to provide a braking deceleration up to the limit of the road surface conditions, but never to exceed 0.6 g. New impact speeds were then calculated for pedestrians that would have been detected by the sensor. These calculations assumed that all pedestrians who were within a given field of view but not obstructed by surrounding objects would be detected. The changes in fatality and severe injury risks were quantified using risk curves derived by logistic regression of the accident data. Summing the risks for all pedestrians, relationships between mitigation effectiveness, sensor field of view, braking initiation time, and deceleration were established. The study documents that the effectiveness at reducing fatally (severely) injured pedestrians in frontal collisions with cars reached 40% (27%) at a field of view of 40 degrees. Increasing the field of view further led to only marginal improvements in effectiveness. PMID:20728647

  16. The Effect of Cashew to The Friction Performance Of Automotive Brake Linings

    OpenAIRE

    Timur, Mustafa; Kılıç, Halil; Sugözü, İlker

    2013-01-01

    Brake linings used in automotive disks are usually composed of various components. Expected properties from a brake lining are appropriate standart value of wear resist, friction coefficient and also economical value. Brake lining extremely warms up during braking due to friction. The braking performance of brake lining changes and braking lining is subject to mecanical deformation due to excessive temperature. In recent twenty years in consequence of fast development in automotive technology...

  17. Simulation and analysis of vehicle stability based on ADAMS/CAR differential brake

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    To improve the braking safety of automobiles, the author studied the effect of differential brake on the stabilities. To analyze the mechanical characteristics of differential brake, automotive subsystem models were built by applying ADAMS/CAR, and automotive mechanics simulation model was built by setting the main subsystems such as body, engine and brake. The simulation model studied the distribution mode of three kinds of differential brake, and beeline braking stability and turning braking stability wer...

  18. Launch Pad in a Box

    Science.gov (United States)

    Mantovani, J. G.; Tamasy, G. J.; Mueller, R. P.; Townsend, I. I.; Sampson, J. W.; Lane, M. A.

    2016-01-01

    NASA Kennedy Space Center (KSC) is developing a new deployable launch system capability to support a small class of launch vehicles for NASA and commercial space companies to test and launch their vehicles. The deployable launch pad concept was first demonstrated on a smaller scale at KSC in 2012 in support of NASA Johnson Space Center's Morpheus Lander Project. The main objective of the Morpheus Project was to test a prototype planetary lander as a vertical takeoff and landing test-bed for advanced spacecraft technologies using a hazard field that KSC had constructed at the Shuttle Landing Facility (SLF). A steel pad for launch or landing was constructed using a modular design that allowed it to be reconfigurable and expandable. A steel flame trench was designed as an optional module that could be easily inserted in place of any modular steel plate component. The concept of a transportable modular launch and landing pad may also be applicable to planetary surfaces where the effects of rocket exhaust plume on surface regolith is problematic for hardware on the surface that may either be damaged by direct impact of high speed dust particles, or impaired by the accumulation of dust (e.g., solar array panels and thermal radiators). During the Morpheus free flight campaign in 2013-14, KSC performed two studies related to rocket plume effects. One study compared four different thermal ablatives that were applied to the interior of a steel flame trench that KSC had designed and built. The second study monitored the erosion of a concrete landing pad following each landing of the Morpheus vehicle on the same pad located in the hazard field. All surfaces of a portable flame trench that could be directly exposed to hot gas during launch of the Morpheus vehicle were coated with four types of ablatives. All ablative products had been tested by NASA KSC and/or the manufacturer. The ablative thicknesses were measured periodically following the twelve Morpheus free flight tests

  19. Activation of PAD4 in NET formation.

    Science.gov (United States)

    Rohrbach, Amanda S; Slade, Daniel J; Thompson, Paul R; Mowen, Kerri A

    2012-01-01

    Peptidylarginine deiminases, or PADs, convert arginine residues to the non-ribosomally encoded amino acid citrulline in a variety of protein substrates. PAD4 is expressed in granulocytes and is essential for the formation of neutrophil extracellular traps (NETs) via PAD4-mediated histone citrullination. Citrullination of histones is thought to promote NET formation by inducing chromatin decondensation and facilitating the expulsion of chromosomal DNA that is coated with antimicrobial molecules. Numerous stimuli have been reported to lead to PAD4 activation and NET formation. However, how this signaling process proceeds and how PAD4 becomes activated in cells is largely unknown. Herein, we describe the various stimuli and signaling pathways that have been implicated in PAD4 activation and NET formation, including the role of reactive oxygen species generation. To provide a foundation for the above discussion, we first describe PAD4 structure and function, and how these studies led to the development of PAD-specific inhibitors. A comprehensive survey of the receptors and signaling pathways that regulate PAD4 activation will be important for our understanding of innate immunity, and the identification of signaling intermediates in PAD4 activation may also lead to the generation of pharmaceuticals to target NET-related pathogenesis. PMID:23264775

  20. Simulation and analysis of vehicle stability based on ADAMS/CAR differential brake

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    To improve the braking safety of automobiles, the author studied the effect of differential brake on the stabilities. To analyze the mechanical characteristics of differential brake, automotive subsystem models were built by applying ADAMS/CAR, and automotive mechanics simulation model was built by setting the main subsystems such as body, engine and brake. The simulation model studied the distribution mode of three kinds of differential brake, and beeline braking stability and turning braking stability were simulated. It shows that differential brake can amend turning shortage of automobile brake and improve its braking stability, but the effect of automobile mass on its braking stability is great. So the distribution mode of braking force and the effect of mass change should be considered while differential brake is applied.

  1. An Intelligent Regenerative Braking Strategy for Electric Vehicles

    Directory of Open Access Journals (Sweden)

    Zhibin Song

    2011-09-01

    Full Text Available Regenerative braking is an effective approach for electric vehicles (EVs to extend their driving range. A fuzzy-logic-based regenerative braking strategy (RBS integrated with series regenerative braking is developed in this paper to advance the level of energy-savings. From the viewpoint of securing car stability in braking operations, the braking force distribution between the front and rear wheels so as to accord with the ideal distribution curve are considered to prevent vehicles from experiencing wheel lock and slip phenomena during braking. Then, a fuzzy RBS using the driver’s braking force command, vehicle speed, battery SOC, battery temperature are designed to determine the distribution between friction braking force and regenerative braking force to improve the energy recuperation efficiency. The experimental results on an “LF620” prototype EV validated the feasibility and effectiveness of regenerative braking and showed that the proposed fuzzy RBS was endowed with good control performance. The maximum driving range of LF620 EV was improved by 25.7% compared with non-RBS conditions.

  2. 49 CFR 571.135 - Standard No. 135; Light vehicle brake systems.

    Science.gov (United States)

    2010-10-01

    ... the braking ratio of the vehicle. Antilock brake system or ABS means a portion of a service brake... neutral. (b) For an EV that is equipped with both ABS and RBS that is part of the service brake system, the ABS must control the RBS. S5.2. Parking brake system. Each vehicle shall be equipped with...

  3. A method to achieve comparable thermal states of car brakes during braking on the road and on a high-speed roll-stand

    Science.gov (United States)

    Wolff, Andrzej

    2010-01-01

    The temperature of a brake friction surface influences significantly the braking effectiveness. The paper describes a heat transfer process in car brakes. Using a developed program of finite element method, the temperature distributions in brake rotors (disc and drum brake) of a light truck have been calculated. As a preliminary consistency criterion of the brake thermal state in road and roll-stand braking conditions, a balance of the energy cumulated in the brake rotor has been taken into account. As the most reliable consistency criterion an equality of average temperatures of the friction surface has been assumed. The presented method allows to achieve on a roll-stand the analogical thermal states of automotive brakes, which are observed during braking in road conditions. Basing on this method, it is possible to calculate the braking time and force for a high-speed roll-stand. In contrast to the previous papers of the author, new calculation results have been presented.

  4. Teach yourself visually iPad

    CERN Document Server

    Hart-Davis, Guy

    2013-01-01

    Fully updated coverage on the latest iPad and iPad mini! As the amazing iPad continues to evolve, so does this invaluable visual guide. Bestselling veteran author Guy Hart-Davis gets you up to date on the latest generation of the iPad, the new iPad Air, as well as the iPad mini with his clear step-by-step, image-driven guidance that is perfectly geared towards those who learn best with visual assistance. You'll get all the latest information for accessing and downloading books, apps, music, and video content as well as sending photos and e-mails, syncing with other devices and services, and

  5. Information Hiding Using Improper Frame Padding

    CERN Document Server

    Jankowski, Bartosz; Szczypiorski, Krzysztof

    2010-01-01

    Hiding information in network traffic may lead to leakage of confidential information. In this paper we introduce a new steganographic system: the PadSteg (Padding Steganography). To authors' best knowledge it is the first information hiding solution which represents interprotocol steganography i.e. usage of relation between two or more protocols from the TCP/IP stack to enable secret communication. PadSteg utilizes ARP and TCP protocols together with an Etherleak vulnerability (improper Ethernet frame padding) to facilitate secret communication for hidden groups in LANs (Local Area Networks). Basing on real network traces we confirm that PadSteg is feasible in today's networks and we estimate what steganographic bandwidth is achievable while limiting the chance of disclosure. We also point at possible countermeasures against PadSteg.

  6. Braking Resistor Scheme for Transient Stability Improvement

    Directory of Open Access Journals (Sweden)

    Saeed Abazari

    2007-09-01

    Full Text Available One of the most important problems in power systems design is increasing the damping of the swing amplitude and also to increase the critical time in transient stability. One of the best techniques is to use resistor braking. However, their performance in power systems, duration of their activity and their place of installation are of great importance. In this paper by using of some of devices in power electronics and by precies modeling of the network and optimal controller is designed which leads as to our final objective. In fact resistor braking are effectively attract additive energy which is a result of disturbances and help us to improve the stability of overall system.

  7. Wind turbine trailing edge aerodynamic brakes

    Energy Technology Data Exchange (ETDEWEB)

    Migliore, P G [National Renewable Energy Lab., Golden, CO (United States); Miller, L S [Wichita State Univ., KS (United States). Dept. of Aerospace Engineering; Quandt, G A

    1995-04-01

    Five trailing-edge devices were investigated to determine their potential as wind-turbine aerodynamic brakes, and for power modulation and load alleviation. Several promising configurations were identified. A new device, called the spoiler-flap, appears to be the best alternative. It is a simple device that is effective at all angles of attack. It is not structurally intrusive, and it has the potential for small actuating loads. It is shown that simultaneous achievement of a low lift/drag ratio and high drag is the determinant of device effectiveness, and that these attributes must persist up to an angle of attack of 45{degree}. It is also argued that aerodynamic brakes must be designed for a wind speed of at least 45 m/s (100 mph).

  8. Modeling of a Hydraulic Braking System

    OpenAIRE

    Lundin, Christopher

    2015-01-01

    The objective of this thesis is to derive an analytical model representing a reduced form of a mine hoist hydraulic braking system. Based primarily on fluid mechanical and mechanical physical modeling, along with a number of simplifying assumptions, the analytical model will be derived and expressed in the form of a system of differential equations including a set of static functions. The obtained model will be suitable for basic simulation and analysis of system dynamics, with the aim to cap...

  9. An Intelligent Auxiliary Vacuum Brake System

    OpenAIRE

    Tong, Chia-Chang; Lin, Jhih-Yu; Li, Shih-Fan; Li, Jiun-Yi

    2009-01-01

    The purpose of this paper focuses on designing an intelligent, compact, reliable, and robust auxiliary vacuum brake system (VBS) with Kalman filter and self-diagnosis scheme. All of the circuit elements in the designed system are integrated into one programmable system-on-chip (PSoC) with entire computational algorithms implemented by software. In this system, three main goals are achieved: (a) Kalman filter and hysteresis controller algorithms are employed within PSoC chip by software to sur...

  10. Bernoulli effect at free revolving flow braking

    OpenAIRE

    Budarin, V. A.

    2013-01-01

    In this research paper, analytical equations for the calculation of radial flow due to the braking on the flat surface plane of revolving flow were obtained. The calculation method is based on the use of pressure force balance equation, viscid friction and inertia. Three motion equations for incompressible, polytropic and isothermal flow were obtained, the type of a cumulative curve for the incompressible flow has been shown. Possibility of the use of radial flow for the compression of water ...

  11. Braking Resistor Scheme for Transient Stability Improvement

    OpenAIRE

    Saeed Abazari

    2007-01-01

    One of the most important problems in power systems design is increasing the damping of the swing amplitude and also to increase the critical time in transient stability. One of the best techniques is to use resistor braking. However, their performance in power systems, duration of their activity and their place of installation are of great importance. In this paper by using of some of devices in power electronics and by precies modeling of the network and optimal controller is designed which...

  12. iPad 4th generation and iPad mini portable genius

    CERN Document Server

    McFedries, Paul

    2012-01-01

    Everything you need to know about the newest iPads from Apple! If you have finally decided to get in the iPad game, then don't forget to pick up the iPad's must-have accessory: your own copy of iPad 4th Generation & iPad mini Portable Genius! This hip little guide is packed with easy-to-understand tips, tricks, and advice to help you get the most out of your iPad with beautiful Retina display or the new iPad mini. You'll learn how to maximize features of the iPad, such as the Retina display, multitouch screen, FaceTime HD camera, Bluetooth and Wi-Fi +4G capability, eReader functionality, an

  13. Beginning iPad Application Development

    CERN Document Server

    Lee, Wei-Meng

    2010-01-01

    A hands-on approach to iPad application development. Beginning iPad Application Development is written to help jumpstart beginning iPad developers. It covers the various topics in such a manner that you will progressively learn without being overwhelmed by the details. It adopts the philosophy that the best way to learn is by doing, hence the numerous Try It Out sections in all the chapters, which first show you how to build something and then explain how things work. Although iPad programming is a huge topic, the aim for this book is to get you started with the fundamentals, and help you unde

  14. iPad for digital photographers

    CERN Document Server

    Story, Derrick

    2013-01-01

    Discover innovative ways to strengthen your photography business with your iPad Many photographers are turning to the flexible, easy-to-use tools of the iPad and relying on them to wear a variety of hats in their photography business. Whether portable portfolio, editing tool, payment-tracking system, or appointment calendar, the iPad melds together the best attributes of the cell phone and a laptop computer and this unique book highlights them all. With this helpful resource, you'll learn how to get the most out of your iPad to not only improve your business but also enhance your p

  15. AARP iPad Tech to Connect

    CERN Document Server

    Boyd, Barbara

    2012-01-01

    The world is at your fingertips with iPad! AARP iPad: Tech to Connect introduces you to the world?s most popular tablet device, the iPad, and all the amazing things it has to offer. In clear, non-technical language, this book guides you through registering and setting up your iPad, getting acquainted with the multitouch interface, navigating around the screen, finding and downloading apps, reading books, listening to music, watching videos, surfing the web, and communicating with friends and family. Developed in partnership with AARP and dedicated to helping readers stay connected with friends

  16. iPad mini for dummies

    CERN Document Server

    Baig, Edward C

    2014-01-01

    Find out why the iPad mini has never been bigger This new edition of iPad mini For Dummies covers all the latest tips and tricks for getting an even bigger bang out of your iPad mini. Presented in full-color and written in the straightforward but fun language that has defined the For Dummies brand for more than twenty years, this friendly guide walks you through the multitouch interface, going online, getting connected, packing your iPad mini with apps, games, e-books, photos, music, and movies, synchronizing your data, texting with iMessage, working with Siri, importing pictures and launching

  17. Failure analysis in locomotive Bogie Brake-Hanger

    Directory of Open Access Journals (Sweden)

    NAVNEET SINGH1

    2012-05-01

    Full Text Available Breakage of brake riggings in WAP7 locomotives has been a matter of concern since 2004, almost afterits commencement of manufacturing, which is having same bogie design as that in WAG9 locomotives. Both ofthese bogies are having TBU/PBU assembly for brakes, but breakage of brake hangers in WAG9 locomotivesare unheard off. Both the inner as well as outer hangers are breaking. However, the cases of breakage of innerhangers towards bogie frame are much more with 80% of the total failures. This paper deliberates to understandthe various failures in locomotive Bogie Brake-Hanger and on root cause analysis for the failure of Brakehanger. In this paper we analyze the characteristics of brake hanger using FEA software.The goal of the project is to develop a high-speed train system capable of reaching the maximum speedand to secure its key technologies, one of which is the braking technology.

  18. Elastoplastic finite element analysis for wet multidisc brake during lasting braking

    Directory of Open Access Journals (Sweden)

    Ji Zhanling

    2015-01-01

    Full Text Available Addressed to serious heat degradation problem of the braking continuously performed in the drag brake application for a long time, finite element analysis for bidirectional thermal-structure coupling is adopted to investigate temperature and stress when material properties are temperature-dependent. Based on the constitutive relations of heat transfer and strain-stress, three-dimensional transient finite element equilibrium equations with many kinds of boundary conditions for bidirectional thermal-structure coupling were derived. And it was originally presented that start time, location, severity and evolution laws of plastic deformation were depicted using dimensionless stress distribution contour with the yield limit related to temperature. The change laws of plastic element number and contact area versus braking time were expressed by plasticity ratio and contact ratio curves, respectively. The laws revealed by the numerical calculation results are in accordance with the objective perception and reasoning.

  19. The Friction of Vehicle Brake Tandem Master Cylinder

    Science.gov (United States)

    Kao, M. J.; Chang, H.; Tsung, T. T.; Lin, H. M.

    2006-10-01

    The behaviour of an elastomeric seal for vehicle brake Tandem master cylinder is measured and analyzed in temperature and brake fluids changed. Working conditions are simulated for different piston rod velocity and cylinder supply pressure, in temperature rising, brakefluid boundary and Nanoaluminum oxide brakefluid oxide brakefluid lubrication. The result shows that Nanoaluminum oxide brakefluid with its ball shape can highly reduce friction coefficient to avoid seal excessive wear and reduce slick slip in brake applications.

  20. The Friction of Vehicle Brake Tandem Master Cylinder

    International Nuclear Information System (INIS)

    The behaviour of an elastomeric seal for vehicle brake Tandem master cylinder is measured and analyzed in temperature and brake fluids changed. Working conditions are simulated for different piston rod velocity and cylinder supply pressure, in temperature rising, brakefluid boundary and Nanoaluminum oxide brakefluid oxide brakefluid lubrication. The result shows that Nanoaluminum oxide brakefluid with its ball shape can highly reduce friction coefficient to avoid seal excessive wear and reduce slick slip in brake applications

  1. Comparative Frictional Analysis of Automobile Drum and Disc Brakes

    OpenAIRE

    H.P. Khairnar; V.M. Phalle; S. S. Mantha

    2016-01-01

    In the present work, a comparative frictional behaviour of drum brakes and disc brakes in automobiles has been investigated. The influential factors; contact force and friction radius were modeled for the estimation of the friction coefficient for drum as well as disc brakes. The effect of contact force and friction radius is studied with varying conditions of parameters; longitudinal force, caliper force and torque on piston side as well as non-piston side. The numerical results obtained hav...

  2. A Model Predictive Control Allocation Approach to Hybrid Braking of Electric Vehicles

    OpenAIRE

    Satzger, Clemens; Pinto de Castro, Ricardo; Buente, Tilman

    2014-01-01

    With the recent emergence of electric drivetrains, a faster and energy efficient braking actuator - the electric motor - has become available to complement the operation of the traditional friction brakes. The decision on how to split the braking torque among the friction brake and the electric motor is one of the main issues of such hybrid braking systems. With this challenge in mind, a new model predictive control allocation (MPCA) approach for hybrid braking is proposed. In comparison to s...

  3. Research on Modeling and Control of Regenerative Braking for Brushless DC Machines Driven Electric Vehicles

    OpenAIRE

    Jian-ping Wen; Chuan-wei Zhang

    2015-01-01

    In order to improve energy utilization rate of battery-powered electric vehicle (EV) using brushless DC machine (BLDCM), the model of braking current generated by regenerative braking and control method are discussed. On the basis of the equivalent circuit of BLDCM during the generative braking period, the mathematic model of braking current is established. By using an extended state observer (ESO) to observe actual braking current and the unknown disturbances of regenerative braking system, ...

  4. 21 CFR 878.4440 - Eye pad.

    Science.gov (United States)

    2010-04-01

    ... FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GENERAL AND PLASTIC SURGERY DEVICES Surgical Devices § 878.4440 Eye pad. (a) Identification. An eye pad is... (general controls). The device is exempt from the premarket notification procedures in subpart E of...

  5. Using iPads to Your Advantage

    Science.gov (United States)

    Zakrzewski, Jennifer L.

    2016-01-01

    In this article, middle school mathematics teacher Jennifer Zakrzewski describes how she successfully incorporated iPads and Apple TV (for projection of iPad screens) into her classroom while having her students solve a problem about mangoes. As Zakrzewski began a unit on multiplying and dividing fractions, she chose to start with the Mangoes…

  6. iPads in learning

    DEFF Research Database (Denmark)

    Meyer, Bente Tobiesen

    2014-01-01

    learning activity. This is specifically relevant when the object of study is mobile learning, where devices are flexible and follow the learner in his/her shifting learning activities and needs. This paper focuses on the ways in which iPads as learning technologies become involved in sociomaterial......Research in learning technologies has often focused on the affordances of single technologies such as pcs, smartphones or interactive whiteboards. However, in most learning environments technologies do not stand alone but are embedded in activity structures and webs of materials that make up the...... practices that are emergent and improvisational and how this contributes to educational change. The paper proposes that the introduction of tablets into classrooms will enroll devices in networks of learning that establish new and significant relationships between learning technologies such as i...

  7. iPad 2 Made Simple

    CERN Document Server

    Mazo, Gary; Ritchie, Rene

    2011-01-01

    The iPad 2 is thinner, more powerful, intuitive and very fun for users of all ages. Your iPad can be used for reading, surfing the web, emailing, watching TV and movies, getting work done and much more. And with over 65,000 apps just for the iPad, as well as the ability to run over 30,000 iPhone apps, the possibilities are endless. iPad 2 Made Simple clarifies all of the key features on the iPad, introduces what's new, and also reveals dozens of time-saving shortcuts and techniques. The book has over 1,000 screen shots that are carefully annotated with step-by-step instructions. * Clear instru

  8. Quality control of cast brake discs

    Directory of Open Access Journals (Sweden)

    M. Stawarz

    2008-04-01

    Full Text Available The largest industrial application so far have the gray cast irons which are characterized by low tensile and bending strength, while at the same time they have good ultimate comprehensive strength. Additionally, the fatigue strength of gray cast irons is comparatively low and they are only to some extend sensitive for the surface waters effects. Cast iron is the material, which is comparatively easy to be processed, and for this reason – it is not expensive. Brake discs are exploited in particularly hard conditions. They must be resistant both against the thermal fatigue and abrasion wearing (at dry friction as well as against seizing, corrosion and mechanical load [1-3]. The gray cast iron, better than other materials, fulfills all the requirements necessary for making the material for the casts resistant against such tough conditions. This work reflects the researches aiming to define the quality of cast brake discs (ventilated and non-ventilated ones upon a period of their exploitation in real conditions. The following researches were performed: evaluations of the disc surface condition, measurement of disc thickness, examination of run – out flank and metallographic analysis. In order to more detailed recognition of mechanisms and reasons of brake discs wearing in real conditions, one should conduct additional examinations: computer analysis of the microstructure, chemical composition analysis, etc., as well as study of the technology of their production in foundries, where they are manufactured [4]. By obtaining the full set of the mentioned above data one can draw final conclusions and remove causes of possible defects.

  9. Design of haptic master featuring small-sized MR brakes

    Science.gov (United States)

    Gang, Han Gyeol; Choi, Seung-Bok; Sohn, Jung Woo

    2016-04-01

    In this work, a new type of haptic master featuring small-sized MR brake is proposed and its performances are evaluated. The proposed haptic master consists of base frame, stick grip and small-sized four MR brakes for 3-DOF rotational motion and 1-DOF gripper motion. To obtain large braking torque under limited small size of MR brake, dual tapered shape inner magnetic core is proposed and its performance is evaluated via both numerical estimation and experimental test. After design and implementation of control algorithm, it has been demonstrated through experiment that the proposed actuator has good performances on tracking control of desired torques. Then, a new haptic master device is designed and constructed by adopting the proposed MR brakes and light weight frame structures. It is verified that the proposed haptic master device is effective for the real application in the field.

  10. A Comparative Study on Automotive Brake Testing Standards

    Science.gov (United States)

    Kumbhar, Bhau Kashinath; Patil, Satyajit Ramchandra; Sawant, Suresh Maruti

    2016-06-01

    Performance testing of automotive brakes involves determination of stopping time, distance and deceleration level. Braking performance of an automobile is required to be ensured for various surfaces like dry, wet, concrete, bitumen etc. as well as for prolonged applications. Various brake testing standards are used worldwide to assure vehicle and pedestrian safety. This article presents methodologies used for automotive service brake testing for two wheelers. The main contribution of this work lies in comparative study of three main brake testing standards; viz. Indian Standards, Federal Motor Vehicle Safety Standards and European Economic Commission Standards. This study shall help the policy makers to choose the best criteria out of these three while formulating newer edition of testing standards.

  11. Radial brake assembly for a control rod drive

    International Nuclear Information System (INIS)

    This patent describes a brake assembly for a control rod drive for selectively preventing travel of a control rod in a nuclear reactor vessel. It comprises a shaft having a longitudinal centerline axis; means for selectively rotating the shaft in a first direction and in a second direction, opposite to the first direction; a stationary housing having a central aperture receiving the shaft; a frame fixedly joined to the housing and having a guide hole; a rotor disc fixedly connected to the shaft for rotation therewith and having at least one rotor tooth extending radially outwardly from a perimeter thereof, the rotor tooth having a locking surface and an inclined surface extending therefrom in a circumferential direction; a brake member disposed adjacent to the rotor disc perimeter and including a base, at least one braking tooth having a locking surface extending therefrom in a circumferential direction, and a plunger extending radially outwardly from the base and slidably joined to the frame through the guide hole; the rotor tooth and the braking tooth being complementary to each other; and means for selectively positioning the brake member in a deployed position abutting the rotor disc perimeter for allowing the braking tooth locking surface to contact the rotor tooth locking surface for preventing rotation of the shaft in the first direction, and in a retracted position spaced radially away from the rotor disc for allowing the rotor disc and the shaft to rotate without restraint from the brake member, the positioning means including a tubular solenoid fixedly joined to the frame and having a central bore disposed around the brake member plunger and effective for sliding the brake member plunger relative to the frame for positioning the brake member in the deployed and retracted positions

  12. Pad B Liquid Hydrogen Storage Tank

    Science.gov (United States)

    Hall, Felicia

    2007-01-01

    Kennedy Space Center is home to two liquid hydrogen storage tanks, one at each launch pad of Launch Complex 39. The liquid hydrogen storage tank at Launch Pad B has a significantly higher boil off rate that the liquid hydrogen storage tank at Launch Pad A. This research looks at various calculations concerning the at Launch Pad B in an attempt to develop a solution to the excess boil off rate. We will look at Perlite levels inside the tank, Boil off rates, conductive heat transfer, and radiant heat transfer through the tank. As a conclusion to the research, we will model the effects of placing an external insulation to the tank in order to reduce the boil off rate and increase the economic efficiency of the liquid hydrogen storage tanks.

  13. iPad 2 The Missing Manual

    CERN Document Server

    Biersdorfer, JD

    2011-01-01

    With iOS 5, Apple added more than 200 new features to the iPad 2, but there's still no printed guide to using all its amazing capabilities. That's where this full-color Missing Manual comes in. You'll learn how to stuff your iPad with media, organize your personal life, wirelessly stream content to and from your tablet, stay connected to friends, and much more. The important stuff you need to know: Build your media library. Fill your iPad with music, movies, TV shows, eBooks, eMagazines, photos, and more.Go wireless. Sync content between your computer and iPad-no wires needed.Get online. Con

  14. Plasma Air Decontamination System (PADS) Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed Plasma Air Decontamination System (PADS) is a trace contaminant control device based on non-thermal atmospheric pressure plasma technology that...

  15. iPad & Siri for dummies

    CERN Document Server

    Baig, Edward C

    2012-01-01

    Two complete e-books on using iPad and Siri for one low price! This unique value-priced e-book set brings together two bestselling For Dummies books in a single e-book file. Including a comprehensive table of contents and the full text of each book, complete with cover, this e-book set helps you get the most out of your iPad and Siri, its artificial intelligence personal assistant. Best of all, you'll pay less than the cost of each book purchased separately. You'll get the complete text of: iPad For Dummies, which helps you toSet up your iPad, browse the

  16. Exploring iPad 2 For Dummies

    CERN Document Server

    Gruman, Galen

    2011-01-01

    Making iPad Easier! The iPad combines the best of your favorite gadgets into one amazing ultraportable touch device. And this cool guide is your one-stop resource for making the most of your iPad 2 or iPad and all it has to offer! Let your fingers lead the wayLearn to navigate the multitouch screen, surf the web, view maps, and even get driving directions, all with a simple touch. That's entertainmentListen to your favorite tunes, watch videos, unwind with a great book, video chat with FaceTime, and find apps to indulge your interests. Take your best shotShoot HD videos and photos, add awesome

  17. iPad for the older and wiser get up and running with your Apple iPad, iPad Air and iPad Mini

    CERN Document Server

    McManus, Sean

    2013-01-01

    Apple's iPad puts a limitless world of entertainment, communication, and everyday functionality in the palms of your hands. iPad for the Older and Wiser, 4th Edition quickly teaches you how to make the most of your new gadget with easy-to-follow instructions. Fully updated to include the iPad Air and iOS 7, this step-by-step guide shows you exactly how to set up your device and discover what it can do - all in jargon-free language. Learn how to: Set up your iPad and copy music and photos from your computerKeep in touch with email and messagesBrowse the web and shop onlineHave video chats wi

  18. Plasma Air Decontamination System (PADS) Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed Plasma Air Decontamination System (PADS) is a trace contaminant control device based on non-thermal atmospheric-pressure plasma technology. Compared to...

  19. Enter the iPad (or Not?)

    Science.gov (United States)

    Waters, John K.

    2010-01-01

    Few computing devices have sparked the burning gizmo lust ignited by the iPad. Apple's latest entry into the tablet PC market didn't generate much heat when it was first unveiled in January, but by April 3, the day of the official release, feverish customers were mobbing Apple stores. The company claims to have sold 300,000 iPads by midnight on…

  20. 49 CFR 236.554 - Rate of pressure reduction; equalizing reservoir or brake pipe.

    Science.gov (United States)

    2010-10-01

    ... or brake pipe. 236.554 Section 236.554 Transportation Other Regulations Relating to Transportation...; Locomotives § 236.554 Rate of pressure reduction; equalizing reservoir or brake pipe. The equalizing-reservoir pressure or brake-pipe pressure reduction during an automatic brake application shall be at a rate not...

  1. Optimal design of a disc-type MR brake for middle-sized motorcycle

    Science.gov (United States)

    Nguyen, Quoc-Hung; Jeon, Juncheol; Choi, Seung-Bok

    2011-03-01

    This research work focuses on optimal design of a disc-type magneto-rheological (MR) brake that can replace a conventional hydraulic brake (CHB) of middle-sized motorcycles. Firstly, a MR brake configuration is proposed considering the available space and the simplicity to replace a CHB by the proposed MR brake. An optimal design of the proposed MR brake is then performed considering the required braking torque, operating temperature, mass and size of the brake. In order to perform the optimization of the brake, the braking torque of the brake is analyzed based on Herschel-Bulkley rheological model of MR fluid. The constrain on operating temperature of the MR brake is determined by considering the steady temperature of the brake when the motorcycle is cruising and the temperature increase during a braking process. An optimization procedure based on finite element analysis integrated with an optimization tool is employed to obtain optimal geometric dimensions of the MR brake. Optimal solution of the MR brake is then presented and simulated performance of the optimized brake is shown with remarkable discussions.

  2. 49 CFR 571.121 - Standard No. 121; Air brake systems.

    Science.gov (United States)

    2010-10-01

    ... brakes. Antilock brake system or ABS means a portion of a service brake system that automatically... reference in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies of the material may be inspected at... control lines and reservoirs that minimizes damage in field operations. Air brake system means a...

  3. 21 CFR 884.5435 - Unscented menstrual pad.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Unscented menstrual pad. 884.5435 Section 884.5435... § 884.5435 Unscented menstrual pad. (a) Identification. An unscented menstrual pad is a device that is a pad made of cellulosic or synthetic material which is used to absorb menstrual or other...

  4. Research on Modeling and Control of Regenerative Braking for Brushless DC Machines Driven Electric Vehicles

    Directory of Open Access Journals (Sweden)

    Jian-ping Wen

    2015-01-01

    Full Text Available In order to improve energy utilization rate of battery-powered electric vehicle (EV using brushless DC machine (BLDCM, the model of braking current generated by regenerative braking and control method are discussed. On the basis of the equivalent circuit of BLDCM during the generative braking period, the mathematic model of braking current is established. By using an extended state observer (ESO to observe actual braking current and the unknown disturbances of regenerative braking system, the autodisturbances rejection controller (ADRC for controlling the braking current is developed. Experimental results show that the proposed method gives better recovery efficiency and is robust to disturbances.

  5. Finite element analysis of advanced bicycle precision brake disk forming technology

    Directory of Open Access Journals (Sweden)

    Chen Dyi-Cheng

    2015-01-01

    Full Text Available In recent years, the bicycle has become an environmentally friendly transportation. The bicycle can be divided into mountain bicycle and highway bicycle. Safe driving is the prior consideration. The bicycle braking system can be divided into oil pressure disk brakes and mechanical disk brakes. The brake disk system is one indispensable component of the safe system. In accordance to overall weight consideration of the bike, the brake disk should also focus on the lightweight design. This paper discussed an innovative brake disk forming technology for 6061 aluminum alloy by the rigid-plastic finite element analysis. The simulation parameters include geometric shapes of the brake disk and mold, die temperature, and friction factors. The stress and strain in forming, brake deformation and vibration modal analysis of brake disk in riding were studied. The paper is expected to offer some precision bicycle brake disk manufacture knowledge for industry.

  6. Residual stresses in a cast iron automotive brake disc rotor

    International Nuclear Information System (INIS)

    Runout, and consequent juddering and pulsation through the brake pedal, is a multi-million dollar per year warranty problem for car manufacturers. There is some suspicion that the runout can be caused by relaxation of residual casting stresses when the disc is overheated during severe-braking episodes. We report here neutron-diffraction measurements of the levels and distribution of residual strains in a used cast iron brake disc rotor. The difficulties of measuring stresses in grey cast iron are outlined and three-dimensional residual-strain distributions are presented and their possible effects discussed

  7. Retardation-controlled safety brake at the test site

    Energy Technology Data Exchange (ETDEWEB)

    Gerlach, A.; Schroeder, R.; Sondermann, W.

    1989-02-01

    A double-drum winding installation is thought to require a retardation-controlled safety brake. The investigations needed for the design acceptance of such a braking installation have so far only been possible on an actual winding installation. This has not ruled out that the commissioning procedure of the whole installation could be delayed or endangered. The use of a simulator developed by the WBK Rope Testing Station, which replicates the behaviour of braked masses in the winding installation, made it possible for the first time to transfer a major part of the necessary investigations to the test site.

  8. MODIFICATION OF FLAKE REINFORCED FRICTION BRAKE COMPOSITE MATERIAL

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    According to the recent development trend and need of the friction brake material, the flake reinforced friction brake material has been made out by adjusting the recipe and techniques. The two-dimensional flake vermiculite is selected as the reinforced stuffing of the material; the modified resin is used as the basal bed of the material. The tests manifest that the properties of mechanics are high, the friction coefficients are suitable and stable,and especially in high temperatures the wear is low. It is an excellent friction brake material.

  9. New Phase-coherent Measurements of Pulsar Braking Indices

    CERN Document Server

    Livingstone, M A; Gavriil, F P; Manchester, R N; Gotthelf, E V; Kuiper, L; Livingstone, Margaret A.; Kaspi, Victoria M.; Gavriil, Fotis P.; Manchester, Richard N.; Kuiper, Lucien

    2007-01-01

    Pulsar braking indices offer insight into the physics that underlies pulsar spin-down. Only five braking indices have been measured via phase-coherent timing; all measured values are less than 3, the value expected from magnetic dipole radiation. Here we present new measurements for three of the five pulsar braking indices, obtained with phase-coherent timing for PSRs J1846-0258 (n=2.65+/-0.01), B1509-58 (n=2.839+/-0.001) and B0540-69 (n=2.140+/-0.009). We discuss the implications of these results and possible physical explanations for them.

  10. Gravitational waves from pulsars with measured braking index

    CERN Document Server

    de Araujo, Jose C N; Costa, Cesar A

    2016-01-01

    We study the putative emission of gravitational waves (GWs) in particular for pulsars with measured braking index. We show that the appropriate combination of both GW emission and magnetic dipole brakes can naturally explain the measured braking index, when the surface magnetic field and the angle between the magnetic dipole and rotation axes are time dependent. Then we discuss the detectability of these very pulsars by aLIGO and the Einstein Telescope. We call attention to the realistic possibility that aLIGO can detect the GWs generated by at least some of these pulsars, such as Vela, for example.

  11. Cycling and wind: does sidewind brake?

    International Nuclear Information System (INIS)

    It is well established that the presence of wind is crucial for the practice of numerous outdoor sports. Among them, the case of cycling competition is especially important because the speeds that are developed are perfectly comparable with moderate or strong winds, giving rise to great variability in race times. Conversely, the sidewind seems to behave as neutral in the race, and nevertheless all the cyclists know the difficulties that it causes. In this brief paper we show that the sidewind also produces an appreciable braking as a consequence of the quadratic dependence of the aerodynamic drag force on the air speed. Our work presents an interesting problem of mechanics and physics of fluids, which may be suitable as a task for intermediate level students in university courses

  12. A Pulsar Eases Off the Brakes

    Science.gov (United States)

    Kohler, Susanna

    2015-10-01

    In 2006, pulsar PSR 18460258 unexpectedly launched into a series of energetic X-ray outbursts. Now a study has determined that this event may have permanently changed the behavior of this pulsar, raising questions about our understanding of how pulsars evolve.Between CategoriesA pulsar a highly magnetized, rotating neutron star that emits a beam of electromagnetic radiation can be powered by one of three mechanisms:Rotation-powered pulsars transform rotational energy into radiation, gradually slowing down in a predictable way.Accretion-powered pulsars convert the gravitational energy of accreting matter into radiation.Magnetars are powered by the decay of their extremely strong magnetic fields.Astronomical classification often results in one pesky object that doesnt follow the rules. In this case, that object is PSR 18460258, a young pulsar categorized as rotation-powered. But in 2006, PSR 18460258 suddenly emitted a series of short, hard X-ray bursts and underwent a flux increase behavior that is usually only exhibited by magnetars. After this outburst, it returned to normal, rotation-powered-pulsar behavior.Since the discovery of this event, scientists have been attempting to learn more about this strange pulsar that seems to straddle the line between rotation-powered pulsars and magnetars.Unprecedented DropOne way to examine whats going on with PSR 18460258 is to evaluate whats known as its braking index, a measure of how quickly the pulsars rotation slows down. For a rotation-powered pulsar, the braking index should be roughly constant. The pulsar then slows down according to a fixed power law, where the slower it rotates, the slower it slows down.In a recent study, Robert Archibald (McGill University) and collaborators report on 7 years worth of timing observations of PSR 18460258 after its odd magnetar-like outburst. They then compare these observations to 6.5 years of data from before the outburst. The team finds that the braking index for this bizarre

  13. Comparisonal Analysis of Manuevering and Braking

    Directory of Open Access Journals (Sweden)

    Artūras Žukas

    2011-04-01

    Full Text Available This article covers the possibility of avoiding a traffic accident considering a car driver who is fallen in a dangerous situation. In such a case, the driver can choose one of the following ways: hard braking or one of the types of maneuvering, including turning off, turning with straightening or changing a line regarding road surface type (dry asphalt, wet asphalt or snowy asphalt. The article also proposes formulas for calculating road distance the car travels till dead stop. Moreover, the tables display theoretical values taking into account various car speeds and road surfaces. The pictures help with determining the most suitable type of action in light of road and weather conditions as well as car speed. The pictures clearly show the dependence of road length on movement speed. At the end of the article, conclusions are proposed.Article in Lithuanian

  14. A novel highly flexible, simple, rapid and low-cost fabrication tool for paper-based microfluidic devices (μPADs) using technical drawing pens and in-house formulated aqueous inks.

    Science.gov (United States)

    Nuchtavorn, Nantana; Macka, Mirek

    2016-05-01

    Paper-based microfluidic devices (μPADs) are capable of achieving rapid quantitative measurements of a variety of analytes inexpensively. μPADs rely on patterning hydrophilic-hydrophobic regions on a sheet of paper in order to create capillary channels within impermeable fluidic brakes on the paper. Here, we present a novel, highly flexible and low-cost fabrication method using a desktop digital craft plotter/cutter and technical drawing pens with tip size of 0.5 mm. The pens were used with either commercial black permanent ink for drawing fluidic brakes, or with specialty in-house formulated aqueous inks. With the permanent marker ink it was possible to create barriers on paper rapidly and in a variety of designs in a highly flexible manner. For instance, a design featuring eight reservoirs can be produced within 10 s for each μPAD with a consistent line width of brakes (%RSD < 1.5). Further, we investigated the optimal viscosity range of in-house formulated inks controlled with additions of poly(ethylene glycol). The viscosity was measured by capillary electrophoresis and the optimal viscosity was in the range of ∼3-6 mPa s. A functional test of these μPADs was conducted by the screening of antioxidant activity. Colorimetric measurements of flavonoid, phenolic compounds and DPPH free radical scavenging activity were carried out on μPADs. The results can be detected by the naked eye and simply quantified by using a camera phone and image analysis software. The fabrication method using technical drawing pens provides flexibility in the use of in-house formulated inks, short fabrication time, simplicity and low cost. PMID:27086101

  15. Brake Pedal Displacement Measuring System based on Machine Vision

    Directory of Open Access Journals (Sweden)

    Chang Wang

    2013-10-01

    Full Text Available Displacement of brake pedal was an important characteristic of driving behavior. This paper proposed a displacement measure algorithm based on machine vision. Image of brake pedal was captured by camera from left side, and images were processed in industry computer. Firstly, average smooth algorithm and wavelet transform algorithm were used to smooth the original image consecutively. Then, edge extracting method which combined Roberts’s operator with wavelet analysis was used to identify the edge of brake pedal. At last, least square method was adopted to recognize the characteristic line of brake pedal’s displacement. The experimental results demonstrated that the proposed method takes the advantages of Roberts’s operator and wavelet transform, it can obtain better measurement result as well as linear displacement sensors

  16. 49 CFR 229.57 - Foundation brake gear.

    Science.gov (United States)

    2010-10-01

    ..., DEPARTMENT OF TRANSPORTATION RAILROAD LOCOMOTIVE SAFETY STANDARDS Safety Requirements Brake System § 229.57... to the wheel to prevent localized thermal stress in the edge of the rim or the flange....

  17. Fishery Management Plan for Morgan Brake National Wildlife Refuge - 1992

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This management plan was prepared by the U. S. Fish and Wildlife Service for Morgan Brake National Wildlife Refuge. Data was provided by the Refuge and Area Office...

  18. Fishery Management Plan for Mathews Brake National Wildlife Refuge - 1985

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This management plan was prepared by the U.S. Fish and Wildlife Service for Mathew's Brake National Wildlife Refuge. Data was provided by the refuge and area office...

  19. Fishing Plan for Mathews Brake National Wildlife Refuge - 1981

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This proposal calls for the opening of Mathews Brake NWR to sport fishing. General regulations pertaining to licenses, creel limits, and methods of taking fish will...

  20. Deployable Engine Air-Brake for Drag Management Applications Project

    Data.gov (United States)

    National Aeronautics and Space Administration — ATA Engineering, Inc, proposes an SBIR program to demonstrate an innovative engine air-brake (EAB) technology that uses a deployable swirl vane mechanism to switch...

  1. Numerical Modeling of Disc Brake System in Frictional Contact

    Directory of Open Access Journals (Sweden)

    A. Belhocine

    2014-03-01

    Full Text Available Safety aspect in automotive engineering has been considered as a number one priority in development of new vehicle. Each single system has been studied and developed in order to meet safety requirement. Instead of having air bag, good suspension systems, good handling and safe cornering, there is one most critical system in the vehicle which is brake systems. The objective of this work is to investigate and analyse the temperature distribution of rotor disc during braking operation using ANSYS Multiphysics. The work uses the finite element analysis techniques to predict the temperature distribution on the full and ventilated brake disc and to identify the critical temperature of the rotor by holding account certain parameters such as; the material used, the geometric design of the disc and the mode of braking. The analysis also gives us, the heat flux distribution for the two discs.

  2. Deployable Engine Air-Brake for Drag Management Applications Project

    Data.gov (United States)

    National Aeronautics and Space Administration — ATA Engineering, Inc., (ATA) proposes a Phase II SBIR program to demonstrate an innovative engine air-brake (EAB) technology that uses a deployable swirl vane...

  3. Handy Brake National Wildlife Refuge Habitat Management Plan

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Handy Brake National Wildlife Refuge Habitat Management Plan provides a longterm vision and specific guidance on managing habitats for the resources of concern...

  4. Mathews Brake National Wildlife Refuge [Land Status Map

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This map was produced by the Division of Realty to depict landownership at Mathews Brake National Wildlife Refuge. It was generated from rectified aerial...

  5. Stability analysis and μ-synthesis control of brake systems

    OpenAIRE

    Lignon, Sylvain; Sinou, Jean-Jacques; Jezequel, Louis

    2006-01-01

    The concept of friction-induced brake vibrations, commonly known as judder, is investigated. Judder vibration is based on the class of geometrically induced or kinematic constraint instability. After presenting the modal coupling mechanism and the associated dynamic model, a stability analysis as well as a sensitivity analysis have been conducted in order to identify physical parameters for a brake design avoiding friction-induced judder instability. Next, in order to reduce the size of the i...

  6. Stability analysis and \\mu-synthesis control of brake systems

    OpenAIRE

    Lignon, Sylvain; Sinou, Jean-Jacques; Jezequel, Louis

    2008-01-01

    The concept of friction-induced brake vibrations, commonly known as judder, is investigated. Judder vibration is based on the class of geometrically induced or kinematic constraint instability. After presenting the modal coupling mechanism and the associated dynamic model, a stability analysis as well as a sensitivity analysis have been conducted in order to identify physical parameters for a brake design avoiding friction-induced judder instability. Next, in order to reduce the size of the i...

  7. 49 CFR 393.55 - Antilock brake systems.

    Science.gov (United States)

    2010-10-01

    ... Motor Vehicle Safety Standard (FMVSS) No. 105 (49 CFR 571.105, S5.5). (b) ABS malfunction indicators for... with an antilock brake system that meets the requirements of FMVSS No. 121 (49 CFR 571.121, S5.1.6.1(b... equipped with an antilock brake system that meets the requirements of FMVSS No. 121 (49 CFR 571.121,...

  8. AASPT Carbon/Carbon Aircraft Brake Disk Granted MPA

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    @@ Xi'an Chaoma Technology Co. Ltd. was issued Parts Manufacturer Approval (PMA) for Carbon/Carbon aircraft brake disk for Airbus 320 series by Civil Aviation Administration of China (CAAC). The company is held by Academy of Aerospace Solid Propulsion Technology (AASPT), a subsidiary of China Aerospace Science and Technology Corporation (CASC). It is the first approval given to a Chinese company to design and produce brakes for main civilian aircraft.

  9. OPTIMAL EMERGENCY VEHICLE BRAKING CONTROL BASED ON DYNAMIC FRICTION MODEL

    OpenAIRE

    Olmos, L.; L. Álvarez-Icaza

    2005-01-01

    A dynamic friction model for the tire-road interface is used in an optimal control scheme for emergency braking of vehicles. The controller sets a target relative velocity curve that the vehicle must track in order to achieve braking in minimum time. It is shown that this curve corresponds to the solution of a minimum time optimal control problem. The final goal of the control is to improve the safety levels in highway transportation.

  10. OPTIMAL EMERGENCY VEHICLE BRAKING CONTROL BASED ON DYNAMIC FRICTION MODEL

    Directory of Open Access Journals (Sweden)

    L. Olmos

    2005-04-01

    Full Text Available A dynamic friction model for the tire-road interface is used in an optimal control scheme for emergency braking ofvehicles. The controller sets a target relative velocity curve that the vehicle must track in order to achieve braking inminimum time. It is shown that this curve corresponds to the solution of a minimum time optimal control problem.The final goal of the control is to improve the safety levels in highway transportation.

  11. Pad testing in incontinent women: a review.

    Science.gov (United States)

    Ryhammer, A M; Djurhuus, J C; Laurberg, S

    1999-01-01

    This article reviews the literature on pad-weighing tests used for objectifying and quantifying incontinence in urinary incontinent women. The patients wear pads weighed before and after the test period. A weight gain is taken as a measure of the amount of urine loss. The tests are in principle of two different types: short-term office tests and long-term home tests, and measure different aspects of urinary control and dysfunction. Both have an inherent large intra- and interindividual variability. Pad weight gains obtained from patients referred for incontinence and those from self-reported continent controls overlap to a certain degree, and it is not possible to identify distinct numerical cut-off values separating continence from incontinence. This suggests that incontinence is a complex condition in which the amount of leakage, other sources of weight gain, and differences in the individual patients' personal characteristics influence the identification and quantification of the problem. In spite of the shortcomings the pad tests remain a valuable tool for both the clinician and the researcher. The home pad tests are superior to the office tests in terms of authenticity, and should be performed with a concomitant systematic registration of the participant's voidings, fluid intake and episodes of incontinence. PMID:10384973

  12. Development of automobile brake lining using pulverized cow hooves

    Directory of Open Access Journals (Sweden)

    Katsina C. BALA

    2016-06-01

    Full Text Available Asbestos has been used for so long as automobile brake lining material because of its good physical and chemical properties. However, due to the health hazard associated with its handling, it has lost favour and several alternative materials are being increasingly used. Asbestos-free brake lining was developed in this work using pulverized cow hooves along with epoxy resin, barium sulphate, graphite and aluminium oxide. This was with a view to exploiting the characteristics of cow hooves, which are largely discarded as waste materials to replace asbestos which has been found to be carcinogenic. Samples of brake linings were produced using compressive moulding in which the physical and mechanical properties of the samples were studied. The results obtained showed that proper bonding was achieved as the percentage by weight of epoxy resin increased and percentage by weight of pulverized cow hooves decreased. The hardness, compressive strength, coefficient of friction, water and oil absorption, relative density and wear rate of the brake linings were determined and compared with existing brake lining properties. The result indicates that pulverized cow hooves can be used as brake lining material for automobiles.

  13. Dynamic characteristics of polymer faced tilting pad journal bearings

    DEFF Research Database (Denmark)

    Simmons, Gregory F.; Cerda Varela, Alejandro Javier; Santos, Ilmar;

    2014-01-01

    Dynamic characteristics of polymer faced tilting pad journal bearings are presented. Investigations are conducted using a single pad, load on pad configuration over a range of shaft speeds and loads. Two polyether ether ketone (PEEK) faced pads, one polytetrafluoroethylene (PTFE) faced pad and two...... entirely PEEK pads are investigated to determine the effect of varying mean bearing pressure and pivot characteristics as well as different material properties of the polymer layer. Experimental results indicate increased damping and decreased stiffness and slightly increased oil film temperature for...... entirely PEEK pads compared to pads with a PEEK lining and steel backing. Similar effects were observed by using a softer (PTFE) pad liner with a steel backing....

  14. Teach Yourself VISUALLY iPad

    CERN Document Server

    Watson, Lonzell

    2010-01-01

    An ideal, visual guide for the image-driven iPad. Whether your interests veer towards movies, games, books, or music—the iPad is the computing device for dazzling graphics, crisp and clear audio, and effortless portability. If ever there existed a device that demanded a reading companion for the visual learner, it's the iPad—and this resource is perfectly suited for the visual audience. Veteran VISUAL author Lonzell Watson walks you through all the features unique to the iPad and shows you how to download books, apps, music, and video content, as well as send photos and e-mails. Plus, you'll d

  15. iPad For Seniors For Dummies

    CERN Document Server

    Muir, Nancy C

    2010-01-01

    The full-color guide to the exciting new iPad, written specifically with the needs of seniors in mind!. The iPad is the perfect device for the senior market, combining the Web, e-mail, photos, video, and book reading into an intuitive, portable device. Written by veteran Dummies author Nancy Muir, this fun and friendly guide shows you how to use the many features and capabilities of the iPad to make life easier! You'll learn how to use the multitouch screen to zoom in and out on Web pages and choose a font and size that makes reading comfortable so that you can get directions, plan vacations,

  16. iPad The Missing Manual

    CERN Document Server

    Biersdorfer, J

    2010-01-01

    The iPad 2 is faster, lighter, and more versatile than its predecessor, but there's still no printed guide to using its amazing features. That's where this full-color Missing Manual comes in. Learn how to stream HD video, make video calls, manage your email, surf the Web, listen to music, play games, and maybe even do a little iWork. This is the book that should have been in the box. Build your media library. Fill your iPad with music, movies, TV shows, eBooks, photos, and more.Share with others. Stream music, HD movies, TV shows, and more, to and from your iPad.Create your own media. Use the

  17. Study of the interaction between microstructure, mechanical and tribo-performance of a commercial brake lining material

    International Nuclear Information System (INIS)

    Highlights: • Interdependencies between the performance influencing parameters are established. • The constituents role is influenced by the heterogeneity of the friction material. • The anisotropy of the material depends essentially on the fiber orientation. • The ability of fibers to participate on load-bearing depends on their orientations. - Abstract: The interaction between microstructure, mechanical, and frictional properties of a commercial brake lining material (BLM) was investigated in order to correlate them to braking performance. For this purpose, a Scanning Electron Microscope (SEM) with energy dispersive X-ray (EDX) mapping and spectrum were used to identify and analyze different constituents. The mechanical properties were determined using compression test. Relevant physical properties (density and porosity) were determined using standard test methods. The friction coefficient and wear behavior of the friction material on contact with the grey cast iron disc were established using a pad-on disc tribometer. The results have shown that the brake lining material contains phenol resin such as the matrix and other various ingredients, including silica, rock and mineral filler reinforcement, barium sulfate and carbon-rich particles as filler and brass particles as friction modifier. It had a varied amount and size up to 1 mm for brass particles. The density and porosity were 1.8 g cm−3 and 7%, respectively. The investigated material exhibited excellent mechanical properties in the normal solicitation direction. The average friction coefficient was about 0.65, whereas the friction coefficient was stable. The different actions of various ingredients in terms of their effects on the friction and wear behavior of the BLM could be related to their different bonding strengths with the resin matrix and their different abilities to form friction films (third-body layer) on the surfaces of the material and transfer films on the counterpart cast iron

  18. Silicon pad detectors for ALICE forward calorimeter

    International Nuclear Information System (INIS)

    A newly designed Electromagnetic Calorimeter (EMC) is being proposed as a possible upgrade in the Forward rapidity region, to enhance the physics capabilities of the ALICE experiment at CERN. Each LHC experiment uses a unique approach, in which preference of the designers and the physics requirements has played a decisive role. The requirement of the design of the calorimeter is to have highly granular layers of detectors consisting of 1 mm2 as well as 1 cm2 silicon pad detectors. The high granular layers (1 mm2) yield good position resolution and tracking of incoming particles. Other active layers, composed of pads of 1 cm2 are used for energy measurement

  19. 17 Pseudoaneurysms Treated by Padding and Compression

    Institute of Scientific and Technical Information of China (English)

    WANGLu-ping; MEIXiao-rong; XUYu-lan; LIUYi; ZHENGCheng-fei; WANGGang

    2004-01-01

    To introduce the method and curative effect of treating pseudoaneurysms by padding and compression. Method: retrospectively analyze the curative effect of treating 17 pseudoaneurysms bypadding hard things and compression. Result: 15 of them was completely recovered by doing so,murmur disappeared and the local skin became even, there was no recurrences and complications after 0.5-3year's following up,but the other two were the same as before the therapy. Conclusion: pseudoaneurysms can be treated effectively by padding and compression

  20. Intelligently Controllable Walker with Magnetorheological Fluid Brake

    Science.gov (United States)

    Kikuchi, Takehito; Tanida, Sosuke; Tanaka, Toshimasa; Kobayashi, Keigo; Mitobe, Kazuhisa

    Caster walkers are supporting frames with casters and wheels. These tools are regularly utilized as life support tools or walking rehabilitation tools in hospitals, nursing homes and individual residences. Users of the walkers can easily move it thanks to its wheels and casters. However falling accidents often happen when it moves without users. The falling accident is very serious problem and one of leading causes of secondary injuries. In the other case, it is hard to move to desired directions if users have imbalance in their motor functions or sensory functions, e.g., hemiplegic patients. To improve safeness and operability of the walkers, we installed compact MR fluid brakes on the wheels and controlled walking speed and direction of the walker. We named this intelligently controllable walker, “i-Walker” and discussed on the control methods and experimental results in this paper. Preliminary trials for direction control of the first-generation of the i-Walker (i-Walker1) are presented. On the basis of the results, we improved the control method and hardware of the i-Walker1, and developed the second-generation (i-Walker2). System description and experimental results of the i-Walker2 are also described. The i-Walker2 has better operability and lower energy consumption than that of the i-Walker1. The line-tracing controller of the i-Walker2 well controls human motions during walking experiments on the target straight line.

  1. Electrostatic Evaluation of the SRB Velostat(Trademark) Pads

    Science.gov (United States)

    Buhler, Charles R.; Calle, Carlos I.

    2007-01-01

    During RSRM Grain inspection, pads constructed of Velostat are grounded and installed in the RSRM bore enabling inspectors to move throughout the bore during the inspection. Velostat pads are installed by grounding the first pad installed and subsequent pads are installed overlapping the previously installed pad maintaining a conductive path to facility ground. Pads are removed upon completion of the inspection in a reverse fashion. As the pads are removed scanning of propellant surfaces is performed per OMRS. During PPICI Audit of B5308.006 (Forward Segment Grain Inspection) in October 07 one audit finding noted that electrostatic scanning of propellant surfaces was being performed during removal of conductive pads following grain inspection. ATK does not perform electrostatic scanning of propellant surfaces during pad removal following final inspection at the plant. The integrated team consisting of NASA SE, USA SE, USA QE, ATK LSS, ATK Systems Safety and ATK DE concurred that electrostatic scanning of propellant surfaces was unnecessary as the conductive pads are grounded. Additional time spent in bore performing scanning presents itself as additional risk. Technicians reported that they have never seen any voltage readings while scanning propellant surfaces during pad removal. USA Systems engineering has written KB 17530 in response to the finding which will delete the requirement (item 2 B47GEN.ll0) to scan propellant surfaces during pad removal. As a result of an E3 panel discussion on December 13, 2007, it was decided that verification of the electrical grounding of the Velostat pads be verified.

  2. Er iPad digital udeskole?

    DEFF Research Database (Denmark)

    Schilhab, Theresa

    2014-01-01

    Hvor ’konkret’ skal en oplevelse være, for at intuitionen om, at det selvoplevede styrker læringen, holder? Er brug af tablets (e.g. iPads) et ligebyrdigt alternativ til den konkrete oplevelse?...

  3. OPTIMUM PAD FOOTING DESIGN BY USING GENETIC ALGORITHM

    Directory of Open Access Journals (Sweden)

    Paki TURGUT

    2008-02-01

    Full Text Available In this study, a Genetic Algorithm (GA has been developed in order to find the optimum geometrical sizes in pad footing design. In the solutions of pad footing sizes found by manually or/and software, there is a required assumption of pad footing sizes held by an experienced designer at the beginning. After the assumption of the initial pad footing sizes, the exact sizes have been determined by a time consuming trial and error process. In the developed GA software without the requirement in the assumption of initial pad footing sizes, the most suitable pad footing sizes has been determined within a short period by minimizing the pad footing volume. In contrast to classical methods, developed GA has simultaneously and relationally calculated the pad footing base sizes and its height.

  4. Optimal design of an automotive magnetorheological brake considering geometric dimensions and zero-field friction heat

    International Nuclear Information System (INIS)

    This paper presents an optimal design of a magnetorheological (MR) brake for a middle-sized passenger car which can replace a conventional hydraulic disc-type brake. In the optimization, the required braking torque, the temperature due to zero-field friction of MR fluid, the mass of the brake system and all significant geometric dimensions are considered. After describing the configuration, the braking torque of the proposed MR brake is derived on the basis of the field-dependent Bingham and Herschel–Bulkley rheological model of the MR fluid. The optimal design of the MR brake is then analyzed taking into account available space, mass, braking torque and steady heat generated by zero-field friction torque of the MR brake. The optimization procedure based on the finite element analysis integrated with an optimization tool is proposed to obtain optimal geometric dimensions of the MR brake. Based on the proposed procedure, optimal solutions of single and multiple disc-type MR brakes featuring different types of MR fluid are achieved. From the results, the most effective MR brake for the middle-sized passenger car is identified and some discussions on the performance improvement of the optimized MR brake are described

  5. Rotor stability estimation with competing tilting pad bearing models

    Science.gov (United States)

    Cloud, C. Hunter; Maslen, Eric H.; Barrett, Lloyd E.

    2012-05-01

    When predicting the stability of rotors supported by tilting pad journal bearings, it is currently debated whether or not the bearings should be represented with frequency dependent dynamics. Using an experimental apparatus, measurements of pad temperatures, unbalance response and stability are compared with modeling predictions for two tilting pad bearing designs. Predictions based on frequency dependent tilting pad bearing dynamics exhibited significantly better correlation with the stability measurements than those assuming frequency independent dynamics.

  6. Prosthetic leg powered by MR brake and SMA wires

    Science.gov (United States)

    Nguyen, The; Munguia, Vicente; Calderon, Jose

    2014-04-01

    Current knee designs for prosthetic legs rely on electric motors for both moving and stationary states. The electric motors draw an especially high level of current to sustain a fixed position. The advantage of using magnetorheological (MR) fluid is that it requires less current and can have a variable braking torque. Besides, the proposed prosthetic leg is actuated by NiTinol wire, a popular shape memory alloy (SMA). The incorporation of NiTinol gives the leg more realistic weight distribution with appropriate arrangement of the batteries and wires. The prosthesis in this research was designed with MR brake as stopping component and SMA wire network as actuating component at the knee. The MR brake was designed with novel non-circular shape for the rotor that improved the braking torque while minimizing the power consumption. The design also helped simplify the control of braking process. The SMA wire network was design so that the knee motion was actively rotated in both directions. The SMA wires were arranged and played very similar role as the leg's muscles. The study started with the overall solid design of the knee including both MR and SMA parts. Theoretical models were derived and programmed in Simulink for both components. The simulation was capable of predicting the power required for moving the leg or hold it in a fixed position for a certain amount of time. Subsequently, the design was prototyped and tested to validate the theoretical prediction. The theoretical models were updated accordingly to correlate with the experimental data.

  7. 21 CFR 880.5270 - Neonatal eye pad.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Neonatal eye pad. 880.5270 Section 880.5270 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL... § 880.5270 Neonatal eye pad. (a) Identification. A neonatal eye pad is an opaque device used to...

  8. 21 CFR 872.3540 - OTC denture cushion or pad.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false OTC denture cushion or pad. 872.3540 Section 872...) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3540 OTC denture cushion or pad. (a) Identification. An OTC denture cushion or pad is a prefabricated or noncustom made disposable device that...

  9. 21 CFR 890.5740 - Powered heating pad.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Powered heating pad. 890.5740 Section 890.5740 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... pad. (a) Identification. A powered heating pad is an electrical device intended for medical...

  10. Optimal design of a magneto-rheological brake absorber for torsional vibration control

    International Nuclear Information System (INIS)

    This research presents an optimal design of a magneto-rheological (MR) brake absorber for torsional vibration control of a rotating shaft. Firstly, the configuration of an MR brake absorber for torsional vibration control of a rotating shaft system is proposed. Then, the braking torque of the MR brake is derived based on the Bingham plastic model of the MR fluid. By assuming that the behaviour of the MR brake absorber is similar to that of a dry friction torsional damper, the optimal braking torque to control the torsional vibration is determined and validated by simulation. The optimal design problem of the MR brake absorber is then developed and a procedure to solve the optimal problem is proposed. Based on the proposed optimal design procedure, the optimal design of a specific rotating shaft system is performed. Vibration control performance of the shaft system employing the optimized MR brake absorber is then investigated through simulation and discussion on the results is given. (paper)

  11. Freshwater Fish Survey of Mathews Brake Water Body - 1980 and 1981

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — A Freshwater Fish Survey of Mathews Brake water body including land not within Mathews Brake NWR. Methods included Electroshocker, creel census, and seine.

  12. 49 CFR 571.116 - Standard No. 116; Motor vehicle brake fluids.

    Science.gov (United States)

    2010-10-01

    ... WHEN ADDING BRAKE FLUID. (2) KEEP BRAKE FLUID CLEAN AND DRY. Contamination with dirt, water, petroleum... paraffin. Do not use a standard with an age exceeding three months. (1) Potassium hydrogen phthalate...

  13. Surrogate models for efficient stability analysis of brake systems

    Science.gov (United States)

    Nechak, Lyes; Gillot, Frédéric; Besset, Sébastien; Sinou, Jean-Jacques

    2015-07-01

    This study assesses capacities of the global sensitivity analysis combined together with the kriging formalism to be useful in the robust stability analysis of brake systems, which is too costly when performed with the classical complex eigenvalues analysis (CEA) based on finite element models (FEMs). By considering a simplified brake system, the global sensitivity analysis is first shown very helpful for understanding the effects of design parameters on the brake system's stability. This is allowed by the so-called Sobol indices which discriminate design parameters with respect to their influence on the stability. Consequently, only uncertainty of influent parameters is taken into account in the following step, namely, the surrogate modelling based on kriging. The latter is then demonstrated to be an interesting alternative to FEMs since it allowed, with a lower cost, an accurate estimation of the system's proportions of instability corresponding to the influent parameters.

  14. Stability Control of Vehicle Emergency Braking with Tire Blowout

    Directory of Open Access Journals (Sweden)

    Qingzhang Chen

    2014-01-01

    Full Text Available For the stability control and slowing down the vehicle to a safe speed after tire failure, an emergency automatic braking system with independent intellectual property is developed. After the system has received a signal of tire blowout, the automatic braking mode of the vehicle is determined according to the position of the failure tire and the motion state of vehicle, and a control strategy for resisting tire blowout additional yaw torque and deceleration is designed to slow down vehicle to a safe speed in an expected trajectory. The simulating test system is also designed, and the testing results show that the vehicle can be quickly stabilized and kept in the original track after tire blowout with the emergency braking system described in the paper.

  15. Dynamics Models of Interacting Torques of Hydrodynamic Retarder Braking Process

    Directory of Open Access Journals (Sweden)

    Wenhao Shen

    2013-01-01

    Full Text Available Hydrodynamic retarder is a kind of assist braking device, which can transfer the vehicle kinetic energy into the heat energy of working medium. There are complicated three-dimensional viscous incompressible turbulent flows in hydrodynamic retarder, so that it is difficult to represent the parameters changing phenomenon and investigate the interactional law. In order to develop a kind of reliable theoretical model for internal flow field, in this study, the dynamics models of interacting torques between impellers and working fluid were constructed based on braking energy transfer principle by using Euler theory to describe the flow state in view of time scale. The model can truly represent the dynamic braking process.

  16. Braking Performance of a Biomimetic Squid-Like Underwater Robot

    Institute of Scientific and Technical Information of China (English)

    Md.Mahbubar Rahman; Sinpei Sugimori; Hiroshi Miki; Risa Yamamoto; Yugo Sanada; Yasuyuki Toda

    2013-01-01

    In this study,the braking performance of the undulating fin propulsion system ofa biomimetic squid-like underwater robot was investigated through free run experiment and simulation of the quasi-steady mathematical model.The quasi-steady equations of motion were solved using the measured and calculated hydrodynamic forces and compared with free-run test results.Various braking strategies were tested and discussed in terms of stopping ability and the forces acting on the stopping stage.The stopping performance of the undulating fin propulsion system tured out to be excellent considering the short stopping time and short stopping distance.This is because of the large negative thrust produced by progressive wave in opposite direction.It was confirmed that the undulating fin propulsion system can effectively perform braking even in complex underwater explorations.

  17. What can the braking indices tell us about pulsars' nature?

    CERN Document Server

    Yue, Y L; Zhu, W W

    2006-01-01

    As a result of observational difficulties, braking indices of only six rotation-powered pulsars are obtained with certainty, all of which are remarkably smaller than the value ($n=3$) expected for pure magnetodipole radiation model. This is still a real fundamental question not being well answered after nearly forty years of the discovery of pulsar. The main problem is that we are shamefully not sure about the dominant mechanisms that result in pulsars' spin-down. Based on the previous works, the braking index is re-examined, with a conclusion of suggesting a constant gap potential drop for pulsars with magnetospheric activities. New constrains on model parameters from observed braking indices are presented.

  18. Simplified model of eddy current brakes and its use for optimization

    OpenAIRE

    Holtmann, Christoph/C.H.; Rinderknecht, Frank/F.R.; Friedrich, Horst E./H.E.F.

    2015-01-01

    The electrification of vehicles makes it possible to think about new concepts to substitute conventional technologies. For example in an electrical drive train, with a traction motor for each wheel mechanical friction brakes can be replaced by eddy current brakes. In this work a method for optimizing the torque density of eddy current brakes is presented. For a fast optimization process the model of the eddy current brake is split up in two levels of detail. In the first level a global model ...

  19. Investigation of Friction Behaviors of Brake Shoe Materials using Metallic Filler

    OpenAIRE

    E. Surojo; Jamasri; V. Malau; M.N. Ilman

    2015-01-01

    Some vehicles use brake shoe made from semi-metallic materials. Semi-metallic brake shoes are made from a combination of metallic and non-metallic materials. Metallic particles are added in the formulation of brake shoe material to improve composites characteristics. In this paper, friction behaviors of brake shoe material using metallic filler were investigated. Machining chips of cast iron and copper wire of electric motor used were incorporated in composite as metallic fillers with amount ...

  20. EFFECT OF GENDER DIFFERENCE ON BRAKE REACTION TIME

    Directory of Open Access Journals (Sweden)

    Ashok

    2016-02-01

    Full Text Available BACKGROUND OF THE STUDY Reaction time is the time taken to respond to a stimulus or change in the environment. It is a method to assess the time taken from the perception of a stimulus followed by mental processing for a motor response. Reaction time in various day to day activities as in driving a car is very important. Brake reaction time (BRT is the time taken for the driver to respond to visualize an object and to press the brake pedal. It is affected by many features like age, gender, neuromuscular disorders. OBJECTIVE OF THE STUDY Study has been undertaken to compare the BRT in male and female drivers and to analyze the effect of sex difference on Brake reaction time. MATERIALS & METHODS Male and female subjects between the age group of 25 – 35 years with driving license were included. Study is conducted in a stationary car. An in-house built; braking timer is fixed to the electric circuit of the braking system in the car. This device is wirelessly connected to the reaction time software installed in the laptop. The subject is instructed to press the brake pedal when the light changed from red to green in the laptop screen. 5 readings are taken and the mean BRT is recorded. STATISTICAL ANALYSIS & RESULTS Statistical analysis done with unpaired student t test indicates that the BRT was more in the females than the males and was statistically significant (p value - 0007. CONCLUSION Gender difference has a significant effect on BRT and reaction time in female is longer than for the males.

  1. iPad all-in-one for dummies

    CERN Document Server

    Muir, Nancy C

    2015-01-01

    For iPad users who want more information than the basics of the iPad,  iPad All-in-One For Dummies provides the goods! Based on Apple's new iOS software, which includes Siri for iPad, new and improved maps with turn by turn directions, shared photo streams, Facebook integration, Passbook, FaceTime video calls over cellular, new calling features such as instant text reply and callback reminders, improved email with a VIP inbox, iCloud browsing tabs, and much more. The book is organized into the following minibooks: iPad Basics - Covers basic functionality, synching with your computer and getti

  2. Designing for the iPad Building Applications that Sell

    CERN Document Server

    Stevens, Chris

    2011-01-01

    Get in the game of developing successful apps for the iPadDesigning for the iPad presents unique challenges for developers and requires an entirely different mindset of elements to consider when creating apps. Written by a highly successful iPad software developer, this book teaches you how to think about the creation process differently when designing iPad apps and escorts you through the process of building applications that have the best chance for success. You'll learn how to take advantage of the iPad's exciting new features and tackle an array of new design challenges so that you can mak

  3. Hierarchical Control Strategy for the Cooperative Braking System of Electric Vehicle

    Directory of Open Access Journals (Sweden)

    Jiankun Peng

    2015-01-01

    Full Text Available This paper provides a hierarchical control strategy for cooperative braking system of an electric vehicle with separated driven axles. Two layers are defined: the top layer is used to optimize the braking stability based on two sliding mode control strategies, namely, the interaxle control mode and signal-axle control strategies; the interaxle control strategy generates the ideal braking force distribution in general braking condition, and the single-axle control strategy can ensure braking safety in emergency braking condition; the bottom layer is used to maximize the regenerative braking energy recovery efficiency with a reallocated braking torque strategy; the reallocated braking torque strategy can recovery braking energy as much as possible in the premise of meeting battery charging power. The simulation results show that the proposed hierarchical control strategy is reasonable and can adapt to different typical road surfaces and load cases; the vehicle braking stability and safety can be guaranteed; furthermore, the regenerative braking energy recovery efficiency can be improved.

  4. Investigation of Product Performance of Al-Metal Matrix Composites Brake Disc using Finite Element Analysis

    Science.gov (United States)

    Fatchurrohman, N.; Marini, C. D.; Suraya, S.; Iqbal, AKM Asif

    2016-02-01

    The increasing demand of fuel efficiency and light weight components in automobile sectors have led to the development of advanced material parts with improved performance. A specific class of MMCs which has gained a lot of attention due to its potential is aluminium metal matrix composites (Al-MMCs). Product performance investigation of Al- MMCs is presented in this article, where an Al-MMCs brake disc is analyzed using finite element analysis. The objective is to identify the potentiality of replacing the conventional iron brake disc with Al-MMCs brake disc. The simulation results suggested that the MMCs brake disc provided better thermal and mechanical performance as compared to the conventional cast iron brake disc. Although, the Al-MMCs brake disc dissipated higher maximum temperature compared to cast iron brake disc's maximum temperature. The Al-MMCs brake disc showed a well distributed temperature than the cast iron brake disc. The high temperature developed at the ring of the disc and heat was dissipated in circumferential direction. Moreover, better thermal dissipation and conduction at brake disc rotor surface played a major influence on the stress. As a comparison, the maximum stress and strain of Al-MMCs brake disc was lower than that induced on the cast iron brake disc.

  5. 49 CFR 232.503 - Process to introduce new brake system technology.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Process to introduce new brake system technology... Technology § 232.503 Process to introduce new brake system technology. (a) Pursuant to the procedures... brake system technology, prior to implementing the plan. (b) Each railroad shall complete a...

  6. METHODOLOGY FOR PARAMETER CALCULATION OF DISK BRAKE MECHANISMS WITH HYDRAULIC CONTROL

    Directory of Open Access Journals (Sweden)

    O. S. Rukteshel

    2014-11-01

    Full Text Available The paper describes a new methodology for a parameter calculation of a disk brake mechanism with hydraulic control that allows to determine a value of hysteresis losses in a brake at the design stage with high accuracy. A complex analysis for obtaining qualitative and quantitative evaluation of design brake parameter influence on hysteresis value in it is presented in the paper.

  7. 49 CFR 232.207 - Class IA brake tests-1,000-mile inspection.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Class IA brake tests-1,000-mile inspection. 232... Class IA brake tests—1,000-mile inspection. (a) Except as provided in § 232.213, each train shall receive a Class IA brake test performed by a qualified person, as defined in § 232.5, at a location...

  8. Correcting Students' Misconceptions about Automobile Braking Distances and Video Analysis Using Interactive Program Tracker

    Science.gov (United States)

    Hockicko, Peter; Trpišová, Beáta; Ondruš, Ján

    2014-01-01

    The present paper informs about an analysis of students' conceptions about car braking distances and also presents one of the novel methods of learning: an interactive computer program Tracker that we used to analyse the process of braking of a car. The analysis of the students' conceptions about car braking distances consisted in…

  9. Hydraulic braking system for loads subjected to impacts and vibrations

    International Nuclear Information System (INIS)

    This invention concerns a hydraulic braking system for loads subjected to impacts and vibrations. These double acting telescopic type hydraulic braking systems possess significant drawbacks linked to possibly important hydraulic leaks due to (a) the use of many dynamic seals in such appliances and (b) the effects of the environment of the system on these seals, particularly when employed in nuclear power stations where the seals reach significant temperatures and are subjected to radiation. Under this invention a remedy is suggested to such drawbacks by integrating means to offset automatically the leaks and the accumulation of hydraulic fluid expansions, as well as facilities to show if such leaks have occurred

  10. Characterization of magnetic tunnel junction test pads

    DEFF Research Database (Denmark)

    Østerberg, Frederik Westergaard; Kjær, Daniel; Nielsen, Peter Folmer;

    2015-01-01

    We show experimentally as well as theoretically that patterned magnetic tunnel junctions can be characterized using the current-in-plane tunneling (CIPT) method, and the key parameters, the resistance-area product (RA) and the tunnel magnetoresistance (TMR), can be determined. The CIPT method...... square tunnel junction pads with varying sizes and analyze the measured data using both the original and the modified CIPT model. Thus, we determine in which sample size range the modified CIPT model is needed to ensure validity of the extracted sample parameters, RA and TMR. In addition, measurements as...... a function of position on a square tunnel junction pad are used to investigate the sensitivity of the measurement results to probe misalignment....

  11. Bit-padding information guided channel hopping

    KAUST Repository

    Yang, Yuli

    2011-02-01

    In the context of multiple-input multiple-output (MIMO) communications, we propose a bit-padding information guided channel hopping (BP-IGCH) scheme which breaks the limitation that the number of transmit antennas has to be a power of two based on the IGCH concept. The proposed scheme prescribes different bit-lengths to be mapped onto the indices of the transmit antennas and then uses padding technique to avoid error propagation. Numerical results and comparisons, on both the capacity and the bit error rate performances, are provided and show the advantage of the proposed scheme. The BP-IGCH scheme not only offers lower complexity to realize the design flexibility, but also achieves better performance. © 2011 IEEE.

  12. Incredible iPad Apps For Dummies

    CERN Document Server

    LeVitus, Bob

    2010-01-01

    Fill your iPad with cool apps with help from this full-color directory!The popularity of the iPad is growing at an unstoppable rate and users are looking for help sorting through the tens of thousands of apps available in the App Store. Packed with helpful reviews and valuable tips on how to make the most of each app, this book walks you through the vast selection of apps and helps you narrow down the most essential and entertaining apps for your needs and interests. Mac guru Bob "Dr. Mac" LeVitus helps you uncover the best of the best apps in business, education, entertainment, finance, healt

  13. Optimization of Double Polishing Pad for STI-CMP Applications

    Energy Technology Data Exchange (ETDEWEB)

    Park, S.W.; Kim, S.Y. [Daebul University, Yeongam (Korea); Seo, Y.J. [Anam Semiconductor Inc., Bucheon (Korea)

    2002-07-01

    Chemical mechanical polishing (CMP) process was required for the global planarization of inter-metal dielectric (IMD), inter-level dielectric (ILD) layers of multi-layer interconnections. In this paper, we studied the characteristics of polishing pad, which can apply shallow trench isolation (STI)-CMP process for global planarization of multi-level interconnection structure. Also, we investigated the effects of different sets of polishing pad, such as soft and hard pad. As an experimental result, hard pad showed ceter-fast type, and soft pad showed edge-fast type. Totally, the defect level has shown little difference, however, the counts of scratch was detected less than 2 on JR111 pad. Through the above results, we can select optimum polishing pad, so we can expect the improvements of throughput and device yield. (author). 11 refs., 8 figs., 1 tab.

  14. On the Design of Tilting-Pad Thrust Bearings

    DEFF Research Database (Denmark)

    Heinrichson, Niels

    2007-01-01

    Pockets are often machined in the surfaces of tilting-pad thrust bearings to allow for hydrostatic jacking in the start-up phase. Pockets and other recesses in the surfaces of bearing pads influence the pressure distribution and thereby the position of the pivot resulting in the most advantageous...... based on the Reynolds equation are used. They include the effects of variations of viscosity with temperature and the deformation of the bearing pads due to pressure and thermal gradients. The models are validated using measurements. Tilting-pad bearings of standard design are studied and the influences...... geometries are given. Parallel-step bearings theoretically have smaller friction coefficients than tilting-pad bearings. A design of a tilting-pad bearing is suggested which combines the benefits of the two types of bearings in a tilting-pad bearing with inlet pockets. This design results in a substantial...

  15. Bearing pad to pressure tube contact simulation

    International Nuclear Information System (INIS)

    Thermal creep strain deformation is a very important pressure tube failure mechanism. During a postulated LOCA (loss of coolant accident) with failure of emergency core injection sys- tem (ECIS), the fuel cladding temperature rapidly increases and the pressure tube becomes completely dry in a few seconds after flow stagnation occurs. Subsequently, the pressure tube circumference is heated by thermal radiation except at the spots where the bearing pads are in direct contact with the pressure tube. Therefore, the localized hot spots are developed on the pressure tube's inner surface under the bearing pads. The main objective of this paper is to evaluate the local thermal-mechanical deformation of a pressure tube in a CANDU reactor and to investigate the fuel channel integrity under localized contact between bearing pad and pressure tube. Furthermore, the mechanistic models are validated against the experimental works per- formed at WRL (Whiteshell research laboratory). Calculations are performed using the finite element method in which the heat, thermal mechanical and creep strain equations are solved, simultaneously. According to the experimental set up, the heat conduction from bearing pads to the inner surface of the pressure tube with appropriate convective and radiation boundary conditions has been simulated. Furthermore, the thermal creep strain deformation has been obtained for when the pressure tube is still under operational condition. It is observed that the pressure tube thermal strain will occur if sufficient high temperature is reached however, depending on the severity of flow degradation in the fuel channel, these localized hot spots could represent a potential creep strain failure of the pressure tube. Whether the pressure tube would fail at these hot spots before contacting the calandria tube depends on the localized temperature and experienced pressure transients. Sensitivity analysis is performed in order to evaluate the contact conductance, the

  16. Steroid-induced Kager's fat pad atrophy

    International Nuclear Information System (INIS)

    We report a rare case of Kager's fat pad atrophy and fibrosis in a 60-year-old woman 1 year after a steroid injection for Achilles tendinopathy. There are few published reports of steroid-induced atrophy affecting deeper layers of fat tissue. To our knowledge, this case report is the first to illustrate its features using magnetic resonance imaging. A review of the scientific literature is also presented. (orig.)

  17. Study of a four Titled Pad Bearing

    Directory of Open Access Journals (Sweden)

    Ibrahim A. Mohsen

    2013-05-01

    Full Text Available This research deal with an analytical study of a four titled pad bearing. These pads are arranged around the journal. A computer program has been used to solve Reynolds equation numerically using the finite difference technique.            The results showed that, the non dimensional force is increased with the increase of the non dimensional load and the gradient of the curve is increased with the decrease of the ( ratio. while the gradient is decreased with the increase of the number of pads which gives less power absorption due to the decrease of the friction force.            Also the results showed  that the eccentricity ratio is in the range of (0.4-0.8 and the maximum attitude angle is (43o. The curve of the relation between the eccentricity ratio and the load number does not start from the zero.            It has been noticed that the increase of the friction factor cause an increase in Summerfield number and the curve gradient is increase with the decrease of the ( ratio. Also the gradient is increased for a fixed value of the ( ratio with the decrease of external load, where as the decrease of the ( ratio cause a decrease of the oil film thickness and this cause an increase of the shearing rate.             Finally, the oil flow rate is increased with the increase of the ( ratio and this would increased more with the increase of the number of pads for the same value of ( ratio which leads to a decrease of the bearing temperature and this maintain the same value of the oil film thickness due to maintaining the same viscosity for the lubricant.

  18. A miniature tilting pad gas lubricated bearing

    Science.gov (United States)

    Sixsmith, H.; Swift, W. L.

    1983-12-01

    This paper describes the design and development of a miniature tilting pad gas bearing developed for use in very small turbomachines. The bearings have been developed for cryogenic turboexpanders with shaft diameters down to about 0.3 cm and rotational speeds up to one million rpm. Cryogenic expansion turbines incorporating this type of bearing should be suitable for refrigeration rates down to about 10 w.

  19. 241-SY modular exhauster pad analysis

    International Nuclear Information System (INIS)

    The purpose of this document is to show the analytical results which were reached in analyzing the new 241-SY modular exhauster concrete pad and retaining wall. The analysis covers wind loading (80 mph), an equivalent static load due to a seismic event, and from those two results, a determination of the pad thickness and the location and size of reinforcement bar was made. The analysis of the exhauster assembly and sampling cabinet evaluated overturning of the assemblies as a whole. An analysis was then performed for the bolting requirements for these two assemblies. The reason why this was broken up into components was to determine if the individual components could take the load exerted by the workset case loading condition, whether it be wind or seismic. The retaining wall that will be located near the new concrete pad was also analyzed. The retaining wall was evaluated to determine the area of reinforcement required, the location of reinforcement, as well as the mass and configuration of the wall to prevent overturning or sliding. The wall was considered Non-Safety Class 4. Additional piping was required to tie-in the new exhauster to the existing primary ventilation ductwork. The design for the tie-in includes two butterfly valves, a tee fitting, elbows, flanges, straight pipe sections, and two new pipe supports to accommodate the additional weight. The valves will enable the new and existing exhausters to be isolated independently. The ductwork, couplings, and supports were analyzed for structural adequacy given Safety Class 2 loads

  20. Inflammation of the infrapatellar fat pad.

    Science.gov (United States)

    Eymard, Florent; Chevalier, Xavier

    2016-07-01

    The infrapatellar fat pad (IFP) of Hoffa's fat pad is the main adipose structure within the knee joint. It is located between the joint capsule and the synovial membrane, which lines its posterior aspect. The IFP is composed chiefly of adipocytes and receives an abundant supply of blood vessels and nerves. Immune cells can infiltrate the IFP, which can become a major source of numerous proinflammatory mediators (cytokines and adipokines). The physiological role for the IFP remains unclear but may involve shock absorption and the protection of adjacent tissues. Hoffa's disease is characterized by inflammation, hypertrophy, and fibrosis of the pad in response to repetitive trauma. Anterior knee pain is the most common symptom. In advanced forms, metaplasia of the IFP may result in the development of a sometimes sizable osteochondroma. The IFP may also contribute to the pathophysiology of knee osteoarthritis, in particular via procatabolic and proinflammatory effects on its synovial lining. Finally, in patients with knee osteoarthritis, inflammation of the IFP may be a source of pain. PMID:27068617

  1. Fallback level concepts for conventional and by-wire automotive brake systems

    International Nuclear Information System (INIS)

    Brake-by-wire represents the replacement of traditional brake components such as pumps, hoses, fluids, brake boosters, and master cylinders by electronic sensors and actuators. The different design of these brake concepts poses new challenges for the automotive industry with regard to availability and fallback levels in comparison to standard conventional brake systems. This contribution focuses on the development of appropriate fallback level concepts. Hardware-in-the-loop (HIL) techniques and field trials will be used to investigate the performance and the usability of such systems.

  2. Analysis of nanoparticles released from the car brakes

    Czech Academy of Sciences Publication Activity Database

    Švábenská, Eva; Roupcová, Pavla; Schneeweiss, Oldřich

    Ostrava: Tanger, 2015. ISBN 978-80-87294-59-8. [NANOCON 2015. International Conference /7./. Brno (CZ), 14.10.2015-16.10.2015] R&D Projects: GA MŠk(CZ) ED1.1.00/02.0068 Institutional support: RVO:68081723 Keywords : nanoparticles * wear debris * automotive brake Subject RIV: JJ - Other Materials

  3. T-type channels: release a brake, engage a gear

    Czech Academy of Sciences Publication Activity Database

    Weiss, Norbert; Laconova, L.

    2016-01-01

    Roč. 10, č. 2 (2016), s. 78-80. ISSN 1933-6950 Institutional support: RVO:61388963 Keywords : gating brake * pore opening * Ca(V)3.3 Subject RIV: CE - Biochemistry Impact factor: 2.410, year: 2014 http://www.tandfonline.com/doi/pdf/10.1080/19336950.2015.1106655

  4. Computational thermo-fluid analysis of a disk brake

    Science.gov (United States)

    Takizawa, Kenji; Tezduyar, Tayfun E.; Kuraishi, Takashi; Tabata, Shinichiro; Takagi, Hirokazu

    2016-06-01

    We present computational thermo-fluid analysis of a disk brake, including thermo-fluid analysis of the flow around the brake and heat conduction analysis of the disk. The computational challenges include proper representation of the small-scale thermo-fluid behavior, high-resolution representation of the thermo-fluid boundary layers near the spinning solid surfaces, and bringing the heat transfer coefficient (HTC) calculated in the thermo-fluid analysis of the flow to the heat conduction analysis of the spinning disk. The disk brake model used in the analysis closely represents the actual configuration, and this adds to the computational challenges. The components of the method we have developed for computational analysis of the class of problems with these types of challenges include the Space-Time Variational Multiscale method for coupled incompressible flow and thermal transport, ST Slip Interface method for high-resolution representation of the thermo-fluid boundary layers near spinning solid surfaces, and a set of projection methods for different parts of the disk to bring the HTC calculated in the thermo-fluid analysis. With the HTC coming from the thermo-fluid analysis of the flow around the brake, we do the heat conduction analysis of the disk, from the start of the breaking until the disk spinning stops, demonstrating how the method developed works in computational analysis of this complex and challenging problem.

  5. Oxygen-Diffused Titanium as a Candidate Brake Rotor Material

    Energy Technology Data Exchange (ETDEWEB)

    Qu, Jun [ORNL; Blau, Peter Julian [ORNL; Jolly, Brian C [ORNL

    2009-01-01

    Titanium alloys are one of several candidate materials for the next generation of truck disk brake rotors. Despite their advantages of lightweight relative to cast iron and good strength and corrosion resistance, titanium alloys are unlikely to be satisfactory brake rotor materials unless their friction and wear behavior can be significantly improved. In this study, a surface engineering process oxygen diffusion was applied to titanium rotors and has shown very encouraging results. The oxygen diffused Ti-6Al-4V (OD-Ti) was tested on a sub-scale brake tester against a flat block of commercial brake lining material and benchmarked against several other Ti-based materials, including untreated Ti-6Al-4V, ceramic particle-reinforced Ti composites (MMCs), and a thermal-spray-coated Ti alloy. With respect to friction, the OD-Ti outperformed all other candidate materials under the imposed test conditions with the friction coefficient remaining within a desirable range of 0.35-0.50, even under the harshest conditions when the disk surface temperature reached nearly 600 C. In addition, the OD-Ti showed significantly improved wear-resistance over the non-treated one and was even better than the Ti-based composite materials.

  6. Electromechanical design and optimization of electromagnetic brake for rail vehicles

    Czech Academy of Sciences Publication Activity Database

    Doležel, Ivo; Moravec, J.; Sedláček, J.; Ulrych, B.

    Lausanne: House EPFL Lausanne, 2005, s. 1-5. [Symposium on Advanced Electromechanical Motion Systems /6/ [0204121]. Lausanne (CH), 27.09.2005-29.09.2005] Institutional research plan: CEZ:AV0Z20570509 Keywords : optimization electromagnetic brake Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering

  7. A Laboratory Activity on the Eddy Current Brake

    Science.gov (United States)

    Molina-Bolivar, J. A.; Abella-Palacios, A. J.

    2012-01-01

    The aim of this paper is to introduce a simple and low-cost experimental setup that can be used to study the eddy current brake, which considers the motion of a sliding magnet on an inclined conducting plane in terms of basic physical principles. We present a set of quantitative experiments performed to study the influence of the geometrical and…

  8. Non-resonant magnetic braking on JET and TEXTOR

    DEFF Research Database (Denmark)

    Sun, Y.; Liang, Y.; Shaing, K.C.;

    2012-01-01

    The non-resonant magnetic braking effect induced by a non-axisymmetric magnetic perturbation is investigated on JET and TEXTOR. The collisionality dependence of the torque induced by the n = 1, where n is the toroidal mode number, magnetic perturbation generated by the error field correction coil...

  9. 16 CFR 1512.5 - Requirements for braking system.

    Science.gov (United States)

    2010-01-01

    ... as determined by the equivalent ground speed specified in § 1512.18(d)(2)(vi). (2) Hand lever access. Hand lever mechanisms shall be located on the handlebars in a position that is readily accessible to... dimension between the brake hand lever and the handlebars in the plane containing the centerlines of...

  10. Analysis of the surface layer of the brake disk

    Czech Academy of Sciences Publication Activity Database

    Švábenská, Eva; Roupcová, Pavla; Podstranská, Ivana; Petr, M.; Filip, J.; Schneeweiss, Oldřich

    Ostrava : TANGER Ltd, 2015. ISBN 978-80-87294-58-1. [METAL 2015. International Conference on Metallurgy and Materials /24./. Brno (CZ), 03.06.2015-05.06.2015] R&D Projects: GA MŠk(CZ) ED1.1.00/02.0068 Institutional support: RVO:68081723 Keywords : grey cast iron * brake disk * microstructure analysis * surface layer Subject RIV: JG - Metallurgy

  11. Braking index of isolated pulsars: open questions and ways forward

    CERN Document Server

    Hamil, Oliver

    2015-01-01

    Isolated pulsars are rotating neutron stars with accurately measured angular velocities $\\Omega$, and their time derivatives which show unambiguously that the pulsars are slowing down. Although the exact mechanism of the spin-down is a question of debate, the commonly accepted view is that it arises either through emission of magnetic dipole radiation (MDR) from a rotating magnetized body, through emission of a relativistic particle wind, or via higher order magnetic multipole or gravitational quadrupole radiation. The calculated energy loss by a rotating pulsar is model dependent and leads to the power law $\\dot{\\Omega}$ = -K $\\Omega^{\\rm n}$ where $n$ is called the braking index. The theoretical value for braking index is $n = 1, 3, 5$ for wind, MDR, quadrupole radiation respectively. The accepted view is that pulsar braking is strongly dominated by MDR. Highly precise observations of isolated pulsars yield braking index values in the range $1 < n < 2.8$ which are consistently less than the value pred...

  12. Can Dark Matter explain the Braking Index of Neutron Stars?

    CERN Document Server

    Kouvaris, Chris

    2014-01-01

    We explore a new mechanism of slowing down the rotation of neutron stars via accretion of millicharged dark matter. We find that this mechanism yields pulsar braking indices that can be substantially smaller than the standard $n\\sim 3$ of the magnetic dipole radiation model for millicharged dark matter particles that are not excluded by existing experimental constraints thus accommodating existing observations.

  13. Wear and related characteristics of an aircraft tire during braking

    Science.gov (United States)

    Mccarty, J. L.

    1972-01-01

    Wear and related characteristics of friction and temperature developed during braking of size 22 x 5.5, type aircraft tires are studied. The testing technique involved gearing the tire to a driving wheel of a ground vehicle to provide operations at constant slip ratios on asphalt, concrete, and slurry-seal surfaces. Data were obtained over the range of slip ratios generally attributed to an aircraft braking system during dry runway operations. The results show that the cumulative tire wear varies linearly with distance traveled and the wear rate increases with increasing slip ratio and is influenced by the runway-surface character. Differences in the wear rates associated with the various surfaces suggest that runways can be rated on the basis of tire wear. The results also show that the friction coefficients developed during fixed-slip-ratio operations are in good agreement with those obtained by other investigators during cyclic braking, in that the dry friction is insensitive to the tire tread temperature is shown to increase with increasing slip ratio and, at the higher ratios, to be greater during braking on asphalt and slurry seal than on concrete.

  14. Can dark matter explain the braking index of neutron stars?

    DEFF Research Database (Denmark)

    Kouvaris, C.; Perez-Garcia, M. A.

    2014-01-01

    We explore a new mechanism of slowing down the rotation of neutron stars via accretion of millicharged dark matter. We find that this mechanism yields pulsar braking indices that can be substantially smaller than the standard n similar to 3 of the magnetic dipole radiation model for millicharged...... dark matter particles that are not excluded by existing experimental constraints thus accommodating existing observations....

  15. Chinese Enterprises Slams the Brakes on Acquisition of Overseas Mines

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    <正>On June 25,China Mining Association revealed that,as of the middle of June,Chinese enterprises slammed the brakes on acquisition of overseas mines.There are only 53 overseas mine acquisition cases so far this year,

  16. Theoretical and experimental studies on a magnetorheological brake operating under compression plus shear mode

    Science.gov (United States)

    Sarkar, C.; Hirani, H.

    2013-11-01

    The torque characteristics of magnetorheological brakes, consisting of rotating disks immersed in a MR fluid and enclosed in an electromagnetic casing, are controlled by regulating the yield stress of the MR fluid. An increase in yield stress increases the braking torque, which means that the higher the yield strength of the MR fluid, the better the performance of the MR brake will be. In the present research an application of compressive force on MR fluid has been proposed to increase the torque capacity of MR brakes. The mathematical expressions to estimate the torque values for MR brake, operating under compression plus shear mode accounting Herschel-Bulkley shear thinning model, have been detailed. The required compressive force on MR fluid of the proposed brake has been applied using an electromagnetic actuator. The development of a single-plate MR disk brake and an experimental test rig are described. Experiments have been performed to illustrate braking torque under different control currents (0.0-2.0 A). The torque results have been plotted and compared with theoretical study. Experimental results as well as theoretical calculations indicate that the braking torque of the proposed MR brake is higher than that of the MR brake operating only under shear.

  17. Theoretical and experimental studies on a magnetorheological brake operating under compression plus shear mode

    International Nuclear Information System (INIS)

    The torque characteristics of magnetorheological brakes, consisting of rotating disks immersed in a MR fluid and enclosed in an electromagnetic casing, are controlled by regulating the yield stress of the MR fluid. An increase in yield stress increases the braking torque, which means that the higher the yield strength of the MR fluid, the better the performance of the MR brake will be. In the present research an application of compressive force on MR fluid has been proposed to increase the torque capacity of MR brakes. The mathematical expressions to estimate the torque values for MR brake, operating under compression plus shear mode accounting Herschel–Bulkley shear thinning model, have been detailed. The required compressive force on MR fluid of the proposed brake has been applied using an electromagnetic actuator. The development of a single-plate MR disk brake and an experimental test rig are described. Experiments have been performed to illustrate braking torque under different control currents (0.0–2.0 A). The torque results have been plotted and compared with theoretical study. Experimental results as well as theoretical calculations indicate that the braking torque of the proposed MR brake is higher than that of the MR brake operating only under shear. (paper)

  18. A low cost, light weight cenosphere–aluminium composite for brake disc application

    Indian Academy of Sciences (India)

    V Saravanan; P R Thyla; S R Balakrishnan

    2016-02-01

    The commonly used composite material for brake rotor consists of silicon carbide (SiC) or aluminium oxide (Al$_2$O$_3$) particles which are more expensive. The weight of conventionally used composite is more compared to base alloy. The aim of this paper is to develop a light weight material for brake disc applications thereby substituting base alloy and conventional composite. This analysis led to 10 vol% cenosphere reinforced aluminium alloy (AA) 6063 composite as the most appropriate material for brake disc. To ensure the manufacturability of composite, composite brake rotor was casted using the sand casting technique and was machined to achieve the final component. Thermal capability of brake disc was ensured by studying temperature variation through vehicle testing procedure of disc brake. Cost reduction is one of the important benefit acquired using cenosphere reinforced composite. This was ensured by cost estimation and analysis. The cost estimated to manufacture the AA6063 brake disc was compared with composite cost.

  19. Synthesis and Characterization of Antifriction Magnetorheological Fluids for Brake

    Directory of Open Access Journals (Sweden)

    Chiranjit Sarkar

    2013-07-01

    Full Text Available Magnetorheological (MR fluids are smart materials with shear strength ranging between zero to 100 kPa under the influence of magnetic field. The present paper discusses the synthesis of MR fluid and its application in brake. In MR brake, gap between stator and rotor is filled with low (off-state viscosity MR fluid. On the application of magnetic field, MR fluid changes its state from liquid to semi-solid by aligning magnetic particles in chains. Due to such chaining action, yield strength of fluid increases, friction between stator and rotor increases and fulfils the braking function. The strength of magnetic particle is a function of relative speed between stator and rotor, applied magnetic field, and volume percentage of magnetic particle. In this study antifriction (off-state and strong chain (on-state CI based MR fluid has been prepared by mixing oleic acid as antifriction additives and tetramethylammonium hydroxide as surfactant to reduce the agglomeration of the MR fluid. Yield strengths of the synthesized MR fluid in on-state and off-state have been compared with commercially available MRF 241ES fluid. A flywheel based MR brake experimental setup has been developed to analyze the performance of designed and developed MR brake.Results show that synthesized MR fluid is stronger and faster in response compared to MRF 241ES fluid.Defence Science Journal, 2013, 63(4, pp.408-412, DOI:http://dx.doi.org/10.14429/dsj.63.2633

  20. Tests of MVD prototype pad detector with a β- source

    International Nuclear Information System (INIS)

    The MVD group has been testing two versions of silicon pad detectors. One design uses a single metal layer for readout trace routing. The second type uses two layers of metal, allowing for greatly simplified signal routing. However, because the readout traces for the pads pass over the other pads in the same column (separated by an oxide layer), the double-metal design introduces crosstalk into the system. A simple test stand using a 90Sr β- source with scintillator triggers was made to estimate the crosstalk. The crosstalk between pads in the same column of the pad detector was 1.6-3.1%. The values measured between pads in different columns were very close to zero. The measured crosstalk was below our maximum allowed value of 7.8%

  1. iPad all-in-one for dummies

    CERN Document Server

    Muir, Nancy C

    2012-01-01

    Six minibooks in one show you how to power-use the iPad For work, play, and life on the road, the iPad has quickly become indispensable, and the new iPad is packed with even more features and power than ever. In this fun and practical guide, long-time For Dummies author Nancy C. Muir walks you through the latest functions, features, and capabilities of the iPad. Get up to speed on the basics, see how to use your iPad to get more organized and productive, learn to use your iPad for work, and discover all the ways to have fun. This book covers it all, and in full color! Packs six minibooks in on

  2. Take control of media on your iPad

    CERN Document Server

    Carlson, Jeff

    2011-01-01

    Join media-savvy author Jeff Carlson as he helps you enjoy media on your iPad like never before. Jeff explains basic and advanced ways of adding media to your iPad, and gives you a thorough grounding in Apple's core media apps-iBooks, iPod, Videos, and Photos. He also helps you integrate your iPad with an Apple TV and looks at various ways of using an iPad as a TV remote. You'll also get plenty of suggestions for third-party apps and products, whether you want to read books not available in the iBookstore, stream music from the Internet to your iPad, convert your own DVD library to iPad-frien

  3. PadSteg: Introducing Inter-Protocol Steganography

    CERN Document Server

    Jankowski, Bartosz; Szczypiorski, Krzysztof

    2011-01-01

    Hiding information in network traffic may lead to leakage of confidential information. In this paper we introduce a new steganographic system: the PadSteg (Padding Steganography). To authors' best knowledge it is the first information hiding solution which represents inter-protocol steganography i.e. usage of relation between two or more protocols from the TCP/IP stack to enable secret communication. PadSteg utilizes ARP and TCP protocols together with an Etherleak vulnerability (improper Ethernet frame padding) to facilitate secret communication for hidden groups in LANs (Local Area Networks). Basing on real network traces we confirm that PadSteg is feasible in today's networks and we estimate what steganographic bandwidth is achievable while limiting the chance of disclosure. We also point at possible countermeasures against PadSteg.

  4. Launch Pad Escape System Design (Human Spaceflight)

    Science.gov (United States)

    Maloney, Kelli

    2011-01-01

    A launch pad escape system for human spaceflight is one of those things that everyone hopes they will never need but is critical for every manned space program. Since men were first put into space in the early 1960s, the need for such an Emergency Escape System (EES) has become apparent. The National Aeronautics and Space Administration (NASA) has made use of various types of these EESs over the past 50 years. Early programs, like Mercury and Gemini, did not have an official launch pad escape system. Rather, they relied on a Launch Escape System (LES) of a separate solid rocket motor attached to the manned capsule that could pull the astronauts to safety in the event of an emergency. This could only occur after hatch closure at the launch pad or during the first stage of flight. A version of a LES, now called a Launch Abort System (LAS) is still used today for all manned capsule type launch vehicles. However, this system is very limited in that it can only be used after hatch closure and it is for flight crew only. In addition, the forces necessary for the LES/LAS to get the capsule away from a rocket during the first stage of flight are quite high and can cause injury to the crew. These shortcomings led to the development of a ground based EES for the flight crew and ground support personnel as well. This way, a much less dangerous mode of egress is available for any flight or ground personnel up to a few seconds before launch. The early EESs were fairly simple, gravity-powered systems to use when thing's go bad. And things can go bad very quickly and catastrophically when dealing with a flight vehicle fueled with millions of pounds of hazardous propellant. With this in mind, early EES designers saw such a passive/unpowered system as a must for last minute escapes. This and other design requirements had to be derived for an EES, and this section will take a look at the safety design requirements had to be derived for an EES, and this section will take a look at

  5. Metal pad instabilities in liquid metal batteries

    CERN Document Server

    Zikanov, Oleg

    2015-01-01

    A mechanical analogy is used to analyze the interaction between the magnetic field, electric current and deformation of interfaces in liquid metal batteries. It is found that, during charging or discharging, a sufficiently large battery is prone to instabilities of two types. One is similar to the metal pad instability known for aluminum reduction cells. Another type is new. It is related to the destabilizing effect of the Lorentz force formed by the azimuthal magnetic field induced by the base current and the current perturbations caused by the local variations of the thickness of the electrolyte layer.

  6. Launch Pad Coatings for Smart Corrosion Control

    Science.gov (United States)

    Calle, Luz M.; Hintze, Paul E.; Bucherl, Cori N.; Li, Wenyan; Buhrow, Jerry W.; Curran, Jerome P.; Whitten, Mary C.

    2010-01-01

    Corrosion is the degradation of a material as a result of its interaction with the environment. The environment at the KSC launch pads has been documented by ASM International (formerly American Society for Metals) as the most corrosive in the US. The 70 tons of highly corrosive hydrochloric acid that are generated by the solid rocket boosters during a launch exacerbate the corrosiveness of the environment at the pads. Numerous failures at the pads are caused by the pitting of stainless steels, rebar corrosion, and the degradation of concrete. Corrosion control of launch pad structures relies on the use of coatings selected from the qualified products list (QPL) of the NASA Standard 5008A for Protective Coating of Carbon Steel, Stainless Steel, and Aluminum on Launch Structures, Facilities, and Ground Support Equipment. This standard was developed to establish uniform engineering practices and methods and to ensure the inclusion of essential criteria in the coating of ground support equipment (GSE) and facilities used by or for NASA. This standard is applicable to GSE and facilities that support space vehicle or payload programs or projects and to critical facilities at all NASA locations worldwide. Environmental regulation changes have dramatically reduced the production, handling, use, and availability of conventional protective coatings for application to KSC launch structures and ground support equipment. Current attrition rate of qualified KSC coatings will drastically limit the number of commercial off the shelf (COTS) products available for the Constellation Program (CxP) ground operations (GO). CxP GO identified corrosion detection and control technologies as a critical, initial capability technology need for ground processing of Ares I and Ares V to meet Constellation Architecture Requirements Document (CARD) CxP 70000 operability requirements for reduced ground processing complexity, streamlined integrated testing, and operations phase affordability

  7. Tilting pad gas bearing design for micro gas turbines

    International Nuclear Information System (INIS)

    This paper presents the results of a dynamic stability investigation of a micro gas turbine supported by two flexible tilting pad bearings. The pad flexibility allows centrifugal and thermal shaft growth of the rotor but can also introduce undesirable rotor instabilities. An eigenvalue analysis on the linearised rotor-bearing dynamics is performed to estimate the required pad stiffness and damping for stability. Results of the eigenvalue analysis are evaluated by fully nonlinear orbit simulations

  8. Elastohydrodynamics Applied to Active Tilting-Pad Journal Bearings

    DEFF Research Database (Denmark)

    Haugaard, Martin Asger; Santos, Ilmar

    2010-01-01

    The static and dynamic properties of tilting-pad journal bearings with controllable radial oil injection are investigated theoretically. The tilting pads are modeled as flexible structures and their behavior is described using a three-dimensional finite element framework and linear elasticity. The...... dynamically perturbed and subsequently condensed to a 2 X 2 system, keeping only the lateral motion of the rotor. As expected, bearing dynamic coefficients are heavily influenced by the control parameters and pad compliance....

  9. Tilting pad gas bearing design for micro gas turbines

    Science.gov (United States)

    Nabuurs, M. J. H. W.; Al-Bender, F.; Reynaerts, D.

    2013-12-01

    This paper presents the results of a dynamic stability investigation of a micro gas turbine supported by two flexible tilting pad bearings. The pad flexibility allows centrifugal and thermal shaft growth of the rotor but can also introduce undesirable rotor instabilities. An eigenvalue analysis on the linearised rotor-bearing dynamics is performed to estimate the required pad stiffness and damping for stability. Results of the eigenvalue analysis are evaluated by fully nonlinear orbit simulations.

  10. 基于Por/E的电机线控制动器结构设计%Structure design of actuator brake by wire based on Por/E

    Institute of Scientific and Technical Information of China (English)

    张兴旺; 初长宝

    2011-01-01

    在Pro/E环境下,利用其内部开发程序,针对电机线控制动器的盘式制动器结构进行参数化设计,包括把圆周运动转化为直线运动的机构、增力机构、圆柱齿轮减速机构等.通过设计制动钳支架、摇臂杆、圆柱齿轮、制动盘、制动块总成、传动件等几何参数以及建立它们之间的基本参数关系,利用Pro/E中的拉伸、旋转功能将草绘图转换成空间轮廓图,并进行着色形成实体,在组件环境下将各零件组装为一体,完成电机线控盘式制动器的结构设计,有效地缩短了产品设计周期.%In the Por/E software environment,a parameterization design was applied to electric actuator structural design of disk brake by wire system by using the internal developing program,including converting the circular movement to the line of sports device,force booster device,cylindrical gear decelerate device.Geometric parameters of brake-caliper frame,rocker arm,cylindrical gear,brake disc,brake pad assembly,transmission—were designed.In order to change from sketching to space outline,stretch and rotation technologies were utilized.Entity model was established by coloration.Each component was assembled in Por/E software environment,and the actuator structural design of brake by wire system was finished.Parameterization design can effectively shorten the product design period.

  11. Pad Safety Personnel Launch Support For STS-200

    Science.gov (United States)

    Guarino, Jennifer

    2007-01-01

    The launch of a space shuttle is a complex and lengthy procedure. There are many places and components to look at and prepare. The components are the orbiter, solid rocket boosters, external tank, and ground equipment. Some of the places are the launch pad, fuel locations, and surrounding structures. Preparations for a launch include equipment checks, system checks, sniff checks for hazardous commodities, and countless walkdowns. Throughout these preparations, pad safety personnel must always be on call. This requires three shifts of multiple people to be ready when needed. Also, the pad safety personnel must be available for the non-launch tasks that are always present for both launch pads

  12. Tilting pad journal bearings - Measured and predicted stiffness coefficients

    Science.gov (United States)

    Parkins, D. W.; Horner, D.

    1993-07-01

    This paper presents measured and calculated characteristics of a tilting pad journal bearing suitable for high speed machinery. Descriptions are given of the experimental techniques used with this variety of bearing and the theoretical model for predicting performance. Measured values of pad temperature, eccentricity, attitude angle, and the four stiffness coefficients are given for a range of loads and rotational speeds. Data are given for both load on pad and between pad configurations, the two principal loading arrangements. Comparisons are made between the measured and predicted bearing temperatures and stiffness coefficients over a wide range of values.

  13. Heavy and Overweight Vehicle Brake Testing: Five-Axle Combination Tractor-Flatbed Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Lascurain, Mary Beth [ORNL; Capps, Gary J [ORNL; Franzese, Oscar [ORNL

    2013-10-01

    The Federal Motor Carrier Safety Administration, in coordination with the Federal Highway Administration, sponsored the Heavy and Overweight Vehicle Brake Testing (HOVBT) program in order to provide information about the effect of gross vehicle weight (GVW) on braking performance. Because the Federal Motor Carrier Safety Regulations limit the number of braking system defects that may exist for a vehicle to be allowed to operate on the roadways, the examination of the effect of brake defects on brake performance for increased loads is also relevant. The HOVBT program seeks to provide relevant information to policy makers responsible for establishing load limits, beginning with providing test data for a combination tractor/trailer. This testing was conducted on a five-axle combination vehicle with tractor brakes meeting the Reduced Stopping Distance requirement rulemaking. This report provides a summary of the testing activities, the results of various analyses of the data, and recommendations for future research. Following a complete brake rebuild, instrumentation, and brake burnish, stopping tests were performed from 20 and 40 mph with various brake application pressures (15 psi, 25 psi, 35 psi, 45 psi, 55 psi, and full system pressure). These tests were conducted for various brake conditions at the following GVWs: 60,000, 80,000, 91,000, 97,000, 106,000, and 116,000 lb. The 80,000-lb GVWs included both balanced and unbalanced loads. The condition of the braking system was also varied. To introduce these defects, brakes (none, forward drive axle, or rear trailer axle) were made inoperative. In addition to the stopping tests, performance-based brake tests were conducted for the various loading and brake conditions. Analysis of the stopping test data showed the stopping distance to increase with load (as expected) and also showed that more braking force was generated by the drive axle brakes than the trailer axle brakes. The constant-pressure stopping test data

  14. Use of a hydraulic brake as a source of thermal energy for the railway rolling stock

    Directory of Open Access Journals (Sweden)

    V.A.Gabrinets

    2012-12-01

    Full Text Available Introduction: In this paper the braking issues of passenger trains which have a great speed and frequent stops are examines. Problem statement: These processes are ехpensive and have big energy losses. The proposed solution to the problem: The kinetic energy of braking prosses propose to turn into thermal energy of heating fluid. For this purpose special hydraulic brake is proposed. The brake is connected with the wheel carriage pairs. The process is based on the energy dissipation in liqid when the disks with spikes rotate in it. Because the real liquid has friction and viscosity, it will be heat up, when the mechanical parts of the hydraulic brake are moved in it. The design, operating principle and characteristics of the hydraulic brake are proposed. Transmission of kinetic energy of carriage motion to brake system executed by mechanical clutches. It connected with the wheel pair and transmitting the energy the wheels rotation to hydraulic brake discs. The cylindrical rods are installed on the discs. Rods location fits the profile of the curved centrifugal pump vanes. As result, the fluid heatind prosess by rotatinge discs with rods take place also at the same time with the liquid pumping through the inner volume of brake system.Conclusions: Affordable passenger carriage braking dynamic is achieved by varying the size and number of rods. The heated liquid may be subsequently used for household needs and for heating the passenger carriage.

  15. Gecko adhesion pad: a smart surface?

    Science.gov (United States)

    Pesika, Noshir S.; Zeng, Hongbo; Kristiansen, Kai; Zhao, Boxin; Tian, Yu; Autumn, Kellar; Israelachvili, Jacob

    2009-11-01

    Recently, it has been shown that humidity can increase the adhesion of the spatula pads that form the outermost (adhesive) surface of the tokay gecko feet by 50% relative to the main adhesion mechanism (i.e. van der Waals adhesive forces), although the mechanism by which the enhancement is realized is still not well understood. A change in the surface hydrophobicity of a gecko setal array is observed when the array, which supports the spatulae, is exposed to a water drop for more than 20 min, suggesting a change in the hydrophilic-lyophilic balance (HLB), and therefore of the conformation of the surface proteins. A surface force apparatus (SFA) was used to quantify these changes, i.e. in the adhesion and friction forces, while shearing the setal array against a silica surface under (i) dry conditions, (ii) 100% humidity and (iii) when fully immersed in water. The adhesion increased in the humid environment but greatly diminished in water. Although the adhesion forces changed significantly, the friction forces remained unaffected, indicating that the friction between these highly textured surfaces is 'load-controlled' rather than 'adhesion-controlled'. These results demonstrate that the gecko adhesive pads have the ability to exploit environmental conditions to maximize their adhesion and stabilize their friction forces. Future designs of synthetic dry adhesives inspired by the gecko can potentially include similar 'smart' surfaces that adapt to their environment.

  16. Gecko adhesion pad: a smart surface?

    International Nuclear Information System (INIS)

    Recently, it has been shown that humidity can increase the adhesion of the spatula pads that form the outermost (adhesive) surface of the tokay gecko feet by 50% relative to the main adhesion mechanism (i.e. van der Waals adhesive forces), although the mechanism by which the enhancement is realized is still not well understood. A change in the surface hydrophobicity of a gecko setal array is observed when the array, which supports the spatulae, is exposed to a water drop for more than 20 min, suggesting a change in the hydrophilic-lyophilic balance (HLB), and therefore of the conformation of the surface proteins. A surface force apparatus (SFA) was used to quantify these changes, i.e. in the adhesion and friction forces, while shearing the setal array against a silica surface under (i) dry conditions, (ii) 100% humidity and (iii) when fully immersed in water. The adhesion increased in the humid environment but greatly diminished in water. Although the adhesion forces changed significantly, the friction forces remained unaffected, indicating that the friction between these highly textured surfaces is 'load-controlled' rather than 'adhesion-controlled'. These results demonstrate that the gecko adhesive pads have the ability to exploit environmental conditions to maximize their adhesion and stabilize their friction forces. Future designs of synthetic dry adhesives inspired by the gecko can potentially include similar 'smart' surfaces that adapt to their environment.

  17. Gecko adhesion pad: a smart surface?

    Energy Technology Data Exchange (ETDEWEB)

    Pesika, Noshir S [Chemical and Biomolecular Engineering Department, Tulane University, New Orleans, LA 70118 (United States); Zeng Hongbo [Chemical and Materials Engineering Department, University of Alberta, Edmonton, AB, T6G 2V4 (Canada); Kristiansen, Kai; Israelachvili, Jacob [Chemical Engineering Department, University of California, Santa Barbara, CA 93117 (United States); Zhao, Boxin [Chemical Engineering Department and Waterloo Institute of Nanotechnology, University of Waterloo, Ontario, N2L 3G1 (Canada); Tian Yu [State Key Laboratory of Tribology, Department of Precision Instruments, Tsinghua University, Beijing 100084 (China); Autumn, Kellar, E-mail: npesika@tulane.ed [Department of Biology, Lewis and Clark College, Portland, OR 97219 (United States)

    2009-11-18

    Recently, it has been shown that humidity can increase the adhesion of the spatula pads that form the outermost (adhesive) surface of the tokay gecko feet by 50% relative to the main adhesion mechanism (i.e. van der Waals adhesive forces), although the mechanism by which the enhancement is realized is still not well understood. A change in the surface hydrophobicity of a gecko setal array is observed when the array, which supports the spatulae, is exposed to a water drop for more than 20 min, suggesting a change in the hydrophilic-lyophilic balance (HLB), and therefore of the conformation of the surface proteins. A surface force apparatus (SFA) was used to quantify these changes, i.e. in the adhesion and friction forces, while shearing the setal array against a silica surface under (i) dry conditions, (ii) 100% humidity and (iii) when fully immersed in water. The adhesion increased in the humid environment but greatly diminished in water. Although the adhesion forces changed significantly, the friction forces remained unaffected, indicating that the friction between these highly textured surfaces is 'load-controlled' rather than 'adhesion-controlled'. These results demonstrate that the gecko adhesive pads have the ability to exploit environmental conditions to maximize their adhesion and stabilize their friction forces. Future designs of synthetic dry adhesives inspired by the gecko can potentially include similar 'smart' surfaces that adapt to their environment.

  18. 40 CFR 264.571 - Assessment of existing drip pad integrity.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 25 2010-07-01 2010-07-01 false Assessment of existing drip pad... DISPOSAL FACILITIES Drip Pads § 264.571 Assessment of existing drip pad integrity. (a) For each existing drip pad as defined in § 264.570 of this subpart, the owner or operator must evaluate the drip pad...

  19. 40 CFR 265.441 - Assessment of existing drip pad integrity.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 25 2010-07-01 2010-07-01 false Assessment of existing drip pad..., STORAGE, AND DISPOSAL FACILITIES Drip Pads § 265.441 Assessment of existing drip pad integrity. (a) For each existing drip pad as defined in § 265.440, the owner or operator must evaluate the drip pad...

  20. Differential Rotation in Neutron Stars Magnetic Braking and Viscous Damping

    CERN Document Server

    Shapiro, S L

    2000-01-01

    Diffferentially rotating stars can support significantly more mass in equilibrium than nonrotating or uniformly rotating stars, according to general relativity. The remnant of a binary neutron star merger may give rise to such a ``hypermassive'' object. While such a star may be dynamically stable against gravitational collapse and bar formation, the radial stabilization due to differential rotation is likely to be temporary. Magnetic braking and viscosity combine to drive the star to uniform rotation, even if the seed magnetic field and the viscosity are small. This process inevitably leads to delayed collapse, which will be accompanied by a delayed gravitational wave burst and, possibly, a gamma-ray burst. We provide a simple, Newtonian, MHD calculation of the braking of differential rotation by magnetic fields and viscosity. The star is idealized as a differentially rotating, infinite cylinder consisting of a homogeneous, incompressible conducting gas. We solve analytically the simplest case in which the ga...

  1. Syntegra: complete integration of traction, bogie and brake systems

    Energy Technology Data Exchange (ETDEWEB)

    Loewenstein, L.; Wangelin, F. von [Siemens AG, Transportation Systems, Erlangen (Germany). Group Technology TS GT; Teichmann, M.; Hoffmann, T. [Siemens TS, Graz (Austria); Joeckel, A. [Siemens Automation and Drives, Nuernberg (Germany)

    2007-07-01

    With Syntegra {sup registered} technology, Siemens has developed an approach to the complete integration of traction, bogie and brake systems, and this has initially been put into practice for metro, underground and S-Bahn (urban regional express) trains. Syntegra constitutes a fundamentally new approach, achieving a greater intensity of integration compared with the types of drive system that have been in use up until now. With Syntegra, the bogie, transmission and brake components are all brought together as part of one and the same system. The integration and, more especially, the technological advances within the three named areas bring about numerous synergies. The new generation of powered bogie features a combination of high efficiency, low dead weight and reduced emissions. A Syntegra drive system achieves a performance which is markedly better than that of conventional systems. (orig.)

  2. Can non-ideal magnetohydrodynamics solve the magnetic braking catastrophe?

    CERN Document Server

    Wurster, James; Bate, Matthew R

    2015-01-01

    We investigate whether or not the low ionisation fractions in molecular cloud cores can solve the `magnetic braking catastrophe', where magnetic fields prevent the formation of circumstellar discs around young stars. We perform three-dimensional smoothed particle non-ideal magnetohydrodynamics (MHD) simulations of the gravitational collapse of one solar mass molecular cloud cores, incorporating the effects of ambipolar diffusion, Ohmic resistivity and the Hall effect alongside a self-consistent calculation of the ionisation chemistry assuming 0.1 micron grains. When including only ambipolar diffusion or Ohmic resistivity, discs do not form in the presence of strong magnetic fields, similar to the cases using ideal MHD. With the Hall effect included, disc formation depends on the direction of the magnetic field with respect to the rotation vector of the gas cloud. When the vectors are aligned, strong magnetic braking occurs and no disc is formed. When the vectors are anti-aligned, a disc with radius of 13AU ca...

  3. Magnetic Braking and Protostellar Disk Formation: The Ideal MHD Limit

    Science.gov (United States)

    Mellon, Richard R.; Li, Zhi-Yun

    2008-07-01

    Magnetic fields are usually considered dynamically important in star formation when the dimensionless mass-to-flux ratio is close to, or less than, unity (λ lesssim 1). We show that, in disk formation, the requirement is far less stringent. This conclusion is drawn from a set of 2D (axisymmetric) simulations of the collapse of rotating, singular isothermal cores magnetized to different degrees. We find that a weak field corresponding to λ ~ 100 can begin to disrupt the rotationally supported disk through magnetic braking, by creating regions of rapid, supersonic collapse in the disk. These regions are separated by one or more centrifugal barriers, where the rapid infall is temporarily halted. The number of centrifugal barriers increases with the mass-to-flux ratio λ. When λ gtrsim 100, they merge together to form a more or less contiguous, rotationally supported disk. Even though the magnetic field in such a case is extremely weak on the scale of dense cores, it is amplified by collapse and differential rotation, to the extent that its pressure dominates the thermal pressure in both the disk and its surrounding region. For relatively strongly magnetized cores with λ lesssim 10, the disk formation is suppressed completely, as found previously. A new feature is that the mass accretion is highly episodic, due to reconnection of the magnetic field lines accumulated near the center. For rotationally supported disks to appear during the protostellar mass accretion phase of star formation in dense cores with realistic field strengths, the powerful magnetic brake must be weakened, perhaps through nonideal MHD effects. Another possibility is to remove, through protostellar winds, the material that acts to brake the disk rotation. We discuss the possibility of observing a generic product of the magnetic braking, an extended circumstellar region that is supported by a combination of toroidal magnetic field and rotation—a "magnetogyrosphere"—interferometrically.

  4. Subway Train Braking System: A Fuzzy Based Hardware Approach

    Directory of Open Access Journals (Sweden)

    Mamun B.I. Reaz

    2011-01-01

    Full Text Available Problem statement: Automated subway train-braking system require perfection, efficiency and fast response. In order to cope with this concerns, an appropriate algorithm need to be developed which need to be implemented in hardware for faster response. Approach: In this research, the FPGA realization of fuzzy based subway train braking system has been presented on an Alter FLEX10K device to provide an accurate and increased speed of convergence of the network. The fuzzy based subway train braking system is comprised of fusilier, inference, rule selector and defuzzifier modules. Sixteen rules are identified for the rule selector module. After determining the membership functions and its fuzzy variables, the Max-Min Composition method and Madman-Min implication operator are used for the inference module and the Centre of Gravity method is used for the defuzzification module. Each module is modeled individually using behavioral VHDL. The layers are then connected using structural VHDL. Two 8-bit and one 8-bit unsigned digital signals are used for input and output respectively. Six ROMs are defined in order to decrease the chances of processing and increasing the throughput of the system. Results: Functional simulations were commenced to verify the functionality of the individual modules and the system as well. We have validated the hardware implementation of the proposed approach through comparison, verification and analysis. The design has utilized 2372 units of LC with a system frequency of 139.8MHz. Conclusion: In this research, the FPGA realization of fuzzy brake system of subway train has been successfully implemented with minimum usage of logic cells. The validation study with C model shows that the hardware model is appropriate and the hardware approach shows faster and accurate response with full automatic control.

  5. Differential Rotation in Neutron Stars: Magnetic Braking and Viscous Damping

    OpenAIRE

    Shapiro, Stuart L.

    2000-01-01

    Diffferentially rotating stars can support significantly more mass in equilibrium than nonrotating or uniformly rotating stars, according to general relativity. The remnant of a binary neutron star merger may give rise to such a ``hypermassive'' object. While such a star may be dynamically stable against gravitational collapse and bar formation, the radial stabilization due to differential rotation is likely to be temporary. Magnetic braking and viscosity combine to drive the star to uniform ...

  6. Carbon nanotube torsional springs for regenerative braking systems

    Science.gov (United States)

    Liu, Sanwei; Martin, Corbin; Lashmore, David; Schauer, Mark; Livermore, Carol

    2015-10-01

    The modeling and demonstration of large stroke, high energy density and high power density torsional springs based on carbon nanotube (CNT) yarns is reported, as well as their application as energy-storing actuators for regenerative braking systems. An originally untwisted CNT yarn is cyclically loaded and unloaded in torsion, with the maximum rotation angle increasing incrementally until failure. The measured average extractable energy density values are 2.9 kJ kg-1  ±  1.2 kJ kg-1 and 3.4 kJ kg-1  ±  0.4 kJ kg-1 for 1-ply CNT yarns and 2-ply CNT yarns, respectively. Additionally, a regenerative braking system is demonstrated to capture the kinetic energy of a wheel and store it as elastic energy in twisted CNT yarns. When the yarn’s twist is released, the stored energy reaccelerates the wheel. The measured energy and mean power densities of the CNT yarns in the simple regenerative braking setup are on average 3.3 kJ kg-1 and 0.67 kW kg-1, respectively, with maximum measured values of up to 4.7 kJ kg-1 and 1.2 kW kg-1, respectively. A slightly lower energy density of up to 1.2 kJ kg-1 and a 0.29 kW kg-1 mean power density are measured for CNT yarns in a more complex setup that mimics a unidirectional rotating regenerative braking mechanism.

  7. Neural Signatures Enhance Emergency Braking Intention Detection during Simulated Driving

    OpenAIRE

    Stefan Haufe; M. F. Gugler; Sagebaum, M.

    2010-01-01

    In many safety-critical areas such as individual car traffic, human performance has become the limiting factor. Modern driving assistance systems can detect potential upcoming crashes and take preparatory measures or even initiate automatic emergency braking.We conducted a driving simulator study (N=20) using a customized version of the open-source racing software TORCS. The experiment comprised 3 blocks (45 minutes each) of driving, in which the subjects had to tightly follow a computer-cont...

  8. SPINDOWN OF ISOLATED NEUTRON STARS: GRAVITATIONAL WAVES OR MAGNETIC BRAKING?

    International Nuclear Information System (INIS)

    We study the spindown of isolated neutron stars from initially rapid rotation rates, driven by two factors: (1) gravitational wave emission due to r-modes and (2) magnetic braking. In the context of isolated neutron stars, we present the first study including self-consistently the magnetic damping of r-modes in the spin evolution. We track the spin evolution employing the RNS code, which accounts for the rotating structure of neutron stars for various equations of state. We find that, despite the strong damping due to the magnetic field, r-modes alter the braking rate from pure magnetic braking for B ≤ 1013 G. For realistic values of the saturation amplitude αsat, the r-mode can also decrease the time to reach the threshold central density for quark deconfinement. Within a phenomenological model, we assess the gravitational waveform that would result from r-mode-driven spindown of a magnetized neutron star. To contrast with the persistent signal during the spindown phase, we also present a preliminary estimate of the transient gravitational wave signal from an explosive quark-hadron phase transition, which can be a signal for the deconfinement of quarks inside neutron stars.

  9. Neuroendocrine brake for the treatment of morbid obesity. Preliminary report

    Directory of Open Access Journals (Sweden)

    Aureo Ludovico de Paula

    2005-06-01

    Full Text Available Objectives: To demonstrate the preliminary results of a newtechnique named neuroendocrine brake, for surgical treatment ofmorbid obesity. Methods: In November 2003, three patientsunderwent the neuroendocrine brake operation performed by thelaparoscopic approach. The mean age was 46.4 years; all patientswere female. Mean BMI was 42.3 kg/m2. The patients selectedpresented some relative or absolute contraindications to the useof gastrointestinal bypass techniques, including gastric ulcer anda family history of gastric malignancy(1 and chronic anemia (2.All patients had associated diseases, including type II diabetesmellitus (2, hypertension (2, obstructive sleep apnea (1,dyslipidemia (3, cholecystolithiasis (1, gastric ulcer (1 andchronic anemia (2. The laparoscopic technique consisted of anileal interposition at the proximal jejunum and longitudinalgastrectomy. Results: There was no conversion to open surgery orpostoperative complications. Sixteen months later, the meanpercentage of initial body weight loss was 44.6% and the meanBMI was 24.3 kg/m2. Glucose, triglyceride and cholesterol levelswere normalized, and sleep apnea showed remission. Conclusion:In spite of the reduced number of patients and short term followup, the good results suggest that the neuroendocrine brake maybecome an option for surgical treatment of morbid obesity in thenear future.

  10. Mechanism analysis and evaluation methodology of regenerative braking contribution to energy efficiency improvement of electrified vehicles

    International Nuclear Information System (INIS)

    Highlights: • The energy flow of an electric vehicle with regenerative brake is analyzed. • Methodology for measuring the regen brake contribution is discussed. • Evaluation parameters of regen brake contribution are proposed. • Vehicle tests are carried out on chassis dynamometer. • Test results verify the evaluation method and parameters proposed. - Abstract: This article discusses the mechanism and evaluation methods of contribution brought by regenerative braking to electric vehicle’s energy efficiency improvement. The energy flow of an electric vehicle considering the braking energy regeneration was analyzed. Then, methodologies for measuring the contribution made by regenerative brake to vehicle energy efficiency improvement were introduced. Based on the energy flow analyzed, two different evaluation parameters were proposed. Vehicle tests were carried out on chassis dynamometer under typical driving cycles with three different control strategies. The experimental results the difference between the proposed two evaluation parameters, and demonstrated the feasibility and effectiveness of the evaluation methodologies proposed

  11. A Combined Cooperative Braking Model with a Predictive Control Strategy in an Electric Vehicle

    Directory of Open Access Journals (Sweden)

    Hongqiang Guo

    2013-12-01

    Full Text Available Cooperative braking with regenerative braking and mechanical braking plays an important role in electric vehicles for energy-saving control. Based on the parallel and the series cooperative braking models, a combined model with a predictive control strategy to get a better cooperative braking performance is presented. The balance problem between the maximum regenerative energy recovery efficiency and the optimum braking stability is solved through an off-line process optimization stream with the collaborative optimization algorithm (CO. To carry out the process optimization stream, the optimal Latin hypercube design (Opt LHD is presented to discrete the continuous design space. To solve the poor real-time problem of the optimization, a high-precision predictive model based on the off-line optimization data of the combined model is built, and a predictive control strategy is proposed and verified through simulation. The simulation results demonstrate that the predictive control strategy and the combined model are reasonable and effective.

  12. Images of triple gas electron multiplier with pixel-pads

    International Nuclear Information System (INIS)

    Testing of a triple gas electron multiplier (GEM) with pixel-pads is described. Images by scanning and suspending radioactive sources were obtained by using 96 channels digital data acquisition (DAQ) system which was composed of 96 8 × 8 mm2 pads and associated electronics channels. (nuclear physics)

  13. EL device pad-printed on a curved surface

    International Nuclear Information System (INIS)

    This paper is unique in that the electroluminescence (EL) display device is fabricated on a curved surface using the pad-printing method. The precision of the pad-printing process is explored to verify whether it can be used for micro patterning. The minimum pattern size and pattern distortion, which is caused by use of the pad, were tested and simulated. The minimal pattern was found to be 35 µm wide and 2.4 µm thick. Pattern distortion when pad-printing on a flat surface, caused by the deformation of the silicon pad, was less than 5 µm. Numerical analysis shows how to estimate pattern distortion when pad-printing on a curved surface. The proposed EL display device consists of five layers, namely a bottom electrode, dielectric layer, phosphor, transparent electrode and a bus electrode. The ink of each layer was reformulated with solvents and the pad-printing conditions were controlled. A PEN film was used first in order to realize the pad-printing process condition of each layer. Finally, the EL display device was printed onto a dish with a radius of curvature of 80 mm. The luminance was 180 cd m−2

  14. iPad Use and Student Engagement in the Classroom

    Science.gov (United States)

    Mango, Oraib

    2015-01-01

    iPads and handheld digital devices have been securing their place in educational institutions surrounded by debates between advocates and skeptics. In light of not enough evidence supporting the use of iPads in education, this study examined the ways that college students in two foreign language classrooms perceived the influence of the use of…

  15. Implementing iPads in the Inclusive Classroom Setting

    Science.gov (United States)

    Maich, Kimberly; Hall, Carmen

    2016-01-01

    This column provides practical suggestions to help guide teachers in utilizing classroom sets of iPads. Following a brief introduction to tablet technology in inclusive classrooms and the origin of these recommendations from a case study focus group, important elements of setting up classroom iPad use, from finding funding to teaching apps, are…

  16. Detecting groan sources in drum brakes of commercial vehicles by TVA-FMEA

    OpenAIRE

    Karabay, Sedat; Baynal, Kasim; İğdeli, Cengiz

    2015-01-01

    In this article, the strategy followed by an automobile company for detecting the root causes of groan complaints related to rear drum brakes in commercial vehicles is presented using data collected from the sold troubled vehicles and from new vehicles from the production line, as well as the drum-brake test rig at the laboratory. Drum brake groan is often very intense and can cause large numbers of customer complaints. During a groan noise event, vehicle structure and suspension components a...

  17. Detecting groan sources in drum brakes of commercial vehicles by TVA-FMEA: a case study:

    OpenAIRE

    Baynal, Kasim; Igdeli, Cengiz; Karabay, Sedat

    2013-01-01

    In this article, the strategy followed by an automobile company for detecting the root causes of groan complaints related to rear drum brakes in commercial vehicles is presented using data collected from the sold troubled vehicles and from new vehicles from the production line, as well as the drum-brake test rig at the laboratory. Drum brake groan is often very intense and can cause large numbers of customer complaints. During a groan noise event, vehicle structure and suspension components a...

  18. Experimental characterization and numerical modelling of the squeal noise generated by railway disc brakes

    OpenAIRE

    CHIELLO,O; LORANG,X; Cordier, JF; MARGIOCCHI,F

    2007-01-01

    The squeal noise generated by railway disk brakes is an everyday source of discomfort for the passengers both inside and outside the trains in stations. The development of silent brake components is needed but beforehand requires a better characterisation and understanding of the phenomenon. This is the aim of the experimental and theoretical investigations performed on high power disc brakes in the framework of the CRISFIS project and presented in this paper. The first part is concerned with...

  19. An approach of inertia compensation based on electromagnetic induction in brake test

    Directory of Open Access Journals (Sweden)

    Xiaowen Li

    2016-04-01

    Full Text Available This paper briefly introduced the operational principle of the brake test bench, and points out the shortcomings when controlling the current of brake test, which means the reference measuring data is instantaneous. Aimed at this deficiency, a current control model based on electromagnetic induction and DC voltage is proposed. On the principle of electromagnetic induction, continuous data and automatic processes are realized. It significantly minimized errors owing to instantaneous data, and maximized the accuracy of the brake test.

  20. Thermo-Mechanical Simulation of Brake Disc Frictional Character by Moment of Inertia

    OpenAIRE

    Fei Gao

    2014-01-01

    The distribution of temperatures gradient and thermal stress of brake disc has been simulated by FEM code to make brake disc thermal stress more homogenously. In this study, using moment of inertia to simulate the realistic brake process instead of theoretically predefines the train deceleration rate, nonlinear deceleration rate and thermo-mechanical behavior has been revealed. The FEM models build upon LS-DYNA® thermo-mechanical code and contact algorithm. Non-uniform temperature alone disc ...

  1. Studies on Horizontal Axis Wind Turbine with Passive Teetered Brake & Damper Mechanism

    OpenAIRE

    Shimizu, Yukimaru; KAMADA, Yasunari; MAEDA, Takao

    1998-01-01

    In order to improve the reliability of megawatt wind turbines, the passive teetered brake & damper mechanism is applied. Its two unique effects, as its name implies, are braking and damping. The passive brake & damper mechanism is useful for variable speed control of the large wind turbine. It is comprised of teetering and feathering mechanisms. When the wind speed exceeds the rated wind speed, the blade is passively teetered in a downwind direction and, at the same time, a feathering mechani...

  2. Launch Pad Flame Trench Refractory Materials

    Science.gov (United States)

    Calle, Luz M.; Hintze, Paul E.; Parlier, Christopher R.; Bucherl, Cori; Sampson, Jeffrey W.; Curran, Jerome P.; Kolody, Mark; Perusich, Steve; Whitten, Mary

    2010-01-01

    The launch complexes at NASA's John F. Kennedy Space Center (KSC) are critical support facilities for the successful launch of space-based vehicles. These facilities include a flame trench that bisects the pad at ground level. This trench includes a flame deflector system that consists of an inverted, V-shaped steel structure covered with a high temperature concrete material five inches thick that extends across the center of the flame trench. One side of the "V11 receives and deflects the flames from the orbiter main engines; the opposite side deflects the flames from the solid rocket boosters. There are also two movable deflectors at the top of the trench to provide additional protection to shuttle hardware from the solid rocket booster flames. These facilities are over 40 years old and are experiencing constant deterioration from launch heat/blast effects and environmental exposure. The refractory material currently used in launch pad flame deflectors has become susceptible to failure, resulting in large sections of the material breaking away from the steel base structure and creating high-speed projectiles during launch. These projectiles jeopardize the safety of the launch complex, crew, and vehicle. Post launch inspections have revealed that the number and frequency of repairs, as well as the area and size of the damage, is increasing with the number of launches. The Space Shuttle Program has accepted the extensive ground processing costs for post launch repair of damaged areas and investigations of future launch related failures for the remainder of the program. There currently are no long term solutions available for Constellation Program ground operations to address the poor performance and subsequent failures of the refractory materials. Over the last three years, significant liberation of refractory material in the flame trench and fire bricks along the adjacent trench walls following Space Shuttle launches have resulted in extensive investigations of

  3. Learning through telepresence with iPads

    DEFF Research Database (Denmark)

    Meyer, Bente Tobiesen

    2015-01-01

    This study aims to present findings from an ongoing study in three rural schools in Denmark where videoconferences are used as part of the teaching at lower secondary level. The research focuses on how students learn from videoconferences that are both one-to-many and peer-to-peer. Videoconferenc......This study aims to present findings from an ongoing study in three rural schools in Denmark where videoconferences are used as part of the teaching at lower secondary level. The research focuses on how students learn from videoconferences that are both one-to-many and peer......-to-peer. Videoconferencing, conceptualized by the schools in question as telepresence, is performed in a unique combination of desktop interaction through mobile devices (iPads) and studio-based large screen lectures and interaction....

  4. Taking Your iPad 2 to the Max

    CERN Document Server

    Sadun, Erica; Sande, Steve

    2011-01-01

    iPad 2: It looks different. It acts different. It connects to the world, yet it is as personal as a well-worn book. And now it has two cameras!. Taking Your iPad 2 to the Max is written so that anyone can quickly get up to speed on Apple's latest hit. As bloggers at The Unofficial Apple Weblog (TUAW.com), the authors have the happy privilege of working with Apple products every day, and they'll guide you through all of the perks of being an iPad 2 owner. This book takes you from selecting and buying an iPad, to connecting it to the Internet, to using the incredible power of the iPad and all it

  5. MRI of Hoffa's fat pad

    Energy Technology Data Exchange (ETDEWEB)

    Saddik, D. [Department of Radiology, Nuffield Orthopaedic Centre, OX3 7LD, Headington, Oxford (United Kingdom); Department of Radiology, Mayne The Avenue Hospital, Melbourne, Victoria (Australia); McNally, E.G. [Department of Radiology, Nuffield Orthopaedic Centre, OX3 7LD, Headington, Oxford (United Kingdom); Richardson, M. [Department of Orthopaedics, Epworth Hospital, Melbourne, Victoria (Australia)

    2004-08-01

    The infrapatellar fat pad of Hoffa is commonly injured but rarely discussed in the radiological literature. Abnormalities within it most commonly are the consequences of trauma and degeneration, but inflammatory and neoplastic diseases of the synovium can be confined to the fat pad. The commonest traumatic lesions follow arthroscopy, but intrinsic signal abnormalities can also be due to posterior and superior impingements syndromes and following patellar dislocation. Infrapatellar plica syndrome may also be traumatic in aetiology. The precise aetiology of ganglion cysts is not understood; the principal differential diagnosis is a meniscal or cruciate cyst. Hoffa's fat pad contains residual synovial tissue, meaning that primary neoplastic conditions of synovium may originate and be confined to the fat pad. Inflammatory changes along the posterior border of the pad may also be used to help differentiate effusion from acute synovitis on unenhanced MR examinations. (orig.)

  6. Pad printer for electronics. Final report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-05-01

    This is the Final report on DARPA-sponsored development Program Pad Printer for Electronics DE-FC04-95AL87486 which was initiated in February, 1995 and intended to run 24 months to February 1997. The Program has significant value to the Thick Film processing industry, an electronic manufacturing alternative for producing functional modules integrated at the multichip level. The result is highly reliable, high volumetric efficiency, subassemblies for military applications and for commercial applications in severe environments, such as automotive, portable communications, and bio-implantable devices. The program progressed quite satisfactorily through 19 months, when it encountered severe, non-technical, difficulties. Resolving these difficulties resulted in several months of delay in completing the Program, but resulted in only a trivial increase in total program cost and no increase in cost to the sponsor. The principle Objective of the Program was the development of a printing system -- machine and appropriate inks -- compatible with existing thick-film processing but offering a 5x improvement in line density. This objective has been met. The Pad Printer is capable of printing suitable inks in traces 25 g wide on 50g centers to a fired thickness of 3 {mu}; each of these parameters is roughly 1/5 the value of the current alternative, silk-screen printing. The available inks represent an assortment of conductor, dielectric, and insulator formulations and the knowledge developed permits extending this family of inks to new and diverse functional materials. An important secondary objective was maximum compatibility with existing Thick Film processing; the printer and ink systems may be substituted directly for the silk screen printers in existing processes. The Program reached or exceeded its other Technical Objectives in almost every case and, in those few instances where the objective was only partially met, work continues under private funding.

  7. Beginning iPad Development for iPhone Developers Mastering the iPad SDK

    CERN Document Server

    Wooldridge, Dave; Mark, D

    2010-01-01

    It's in magazines and newspapers, it's on television and radio, it's on busses and billboards and pretty much everywhere you look (except for Apple stores, where it's likely still sold out). The iPad is the hot new touchscreen tablet from Apple, representing the next generation of mobile computing.Packed with dozens of new features, the iOS 3.2 SDK enables you to build sophisticated, desktop-quality apps for this exciting new platform. Every iPhone and iPod touch app developer looking to take the next step and move into the iPad arena will want to read this book from cover to cover. Beginning

  8. The performance of T-pad bearing pads, as a remedy against pressure tube crevice corrosion, on bundles irradiated at Bruce and Point Lepreau

    International Nuclear Information System (INIS)

    Crevice corrosion in CANDU reactors can occur between the standard design fuel bundle bearing pads and the pressure tube when the element operates at a sufficiently high power to create the crevice boiling condition necessary for the concentration of lithium hydroxide leading to enhanced oxidation of the bearing pad and pressure tube. Since crevice corrosion was discovered in Pickering pressure tubes, a concerted effort has been made on design changes to the standard bearing pads in order to minimize/elirninate crevice corrosion. This development program led to the T-Pad bearing pad design. Recent demonstration irradiations of prototype bundles, fitted with T-Pad bearing pads, were conducted in Bruce and Point Lepreau Nuclear Generating Stations. The subsequent post-irradiation examinations indicated, that except for increased hydrogen and deuterium pickup in the T-Pads, the performance of the T-Pads and bundles is consistent with standard bearing pad bundles. (author)

  9. Fat pad entrapment at the hip: a new diagnosis.

    Directory of Open Access Journals (Sweden)

    Narlaka Jayasekera

    Full Text Available PURPOSE: To establish if a positive impingement sign in femoroacetabular impingement (FAI may result from entrapment of the fat pad located at the anterior head-neck junction of the upper femur. This fat pad is routinely removed before any cam lesion excision. METHODS: We report a prospective study of 142 consecutive hip arthroscopies for symptomatic FAI where the aim was to remove the arthroscopically identified area of impingement, not necessarily to create a spherical femoral head. Patients were divided into two groups. Group 1 (n = 92; 34 females, 58 males, where a cam-type bony FAI lesion was identified and excised in addition to the fat pad which overlay it, and Group 2 (n = 50; 29 females, 21 males where the only identified point of impingement was a prominent fat pad. In this situation the fat pad was excised in isolation and the underlying bone preserved. Patients were assessed preoperatively, at six weeks, six months, one year and two years with a modified Harris hip score (mHHS. RESULTS: Both groups were comparable preoperatively for mean age, mean alpha angle and mean anterior offset ratio. Both groups improved significantly after surgery at all time points. However, Group 1 (fat pad and bone resection demonstrated 16.0% improvement in mHHS by two years while for Group 2 (fat pad resection only the improvement was 18.9% (p = 0.628. CONCLUSIONS: The fat pad found at the anterior head/neck junction of the hip joint can be a source of pain and we propose fat pad entrapment as a new, previously undescribed diagnosis. Our findings also suggest that a large number of cam lesions are being excised unnecessarily and that further efforts should be made to understand the role of the fat pad as a source of groin discomfort. LEVEL OF EVIDENCE: Level IV, case series.

  10. Calculation of pad cross-talk in a thin-gap multiwire detector with pad readout

    International Nuclear Information System (INIS)

    Mechanisms responsible for cross-talk in a thin-gap multiwire chamber with pad readout are discussed. Using a simple capacitive coupling model, the cross-talk is calculated as a function of chamber geometry, capacitances and charge integration time. Calculation results are compared and found to be in reasonable agreement with measurements. Suggestions are given for reducing cross-talk in such a chamber. (orig.)

  11. Design of a squeeze film magnetorheological brake considering compression enhanced shear yield stress of magnetorheological fluid

    Science.gov (United States)

    Sarkar, C.; Hirani, H.

    2013-02-01

    A magnetorheological brake, consisting of rotating disks immersed in a MR fluid and enclosed in an electromagnet, is proposed to replace the conventional heavy weight low response hydraulic disk brake. The frictional characteristics of the proposed brake can be controlled by regulating the yield stress of the MR fluid as function of magnetic field and normal compressive force. The controllable yield stress retards the surfaces of rotating disks, thus MR fluid can be used as a brake lining material. The present research work attempts designing a squeeze film MR brake by accounting compression enhanced shear yield stress of magnetorheological fluid. Theoretical calculations indicate that the estimated braking torque of the six plate squeeze film MR brake, under compression, is in the order of 600Nm. To validate the theoretical design and its findings, a prototype of single-plate squeeze film MR disk brake has been developed. Experimental test setup helps to illustrate braking torque under different control currents (0.0 to 1.25 A).

  12. Characteristic Analysis and Control of a Hybrid Excitation Linear Eddy Current Brake

    OpenAIRE

    Baoquan Kou; Yinxi Jin; Lu Zhang; He Zhang

    2015-01-01

    In this paper, a novel hybrid excitation linear eddy current brake is presented as a braking system for high-speed road and rail vehicles. The presence of the permanent magnets (PMs), whose flux lines in the primary core are oppositely directed with respect to the flux lines by the excitation windings, has the effect of mitigating the saturation of the iron in the teeth of the primary core. This allows the brake to be fed with more intense currents, improving the braking force. First, using...

  13. Optimal design of a novel hybrid MR brake for motorcycles considering axial and radial magnetic flux

    International Nuclear Information System (INIS)

    This work presents an optimal solution of a new type of motorcycle brake featuring different smart magnetorheological (MR) fluids. In this study, typical types of commercial MR fluid are considered there for the design of a motorcycle MR brake; MRF-122-2ED (low yield stress), MRF-132-DG (medium yield stress) and MRF-140-CG (high yield stress). As a first step, a new configuration featuring a T-shaped drum MR brake is introduced and a hybrid concept of magnetic circuit (using both axial and radial magnetic flux) to generate braking force is analyzed based on the finite element method. An optimal design of the MR brake considering the required braking torque, the temperature due to friction of the MR fluid, the mass of the brake system and all significant geometric dimensions is then performed. For the optimization, the finite element analysis (FEA) is used to achieve principal geometric dimensions of the MR brake. In addition, the size, mass and power consumption of three different MR motorcycle brakes are quantitatively analyzed and compared. (paper)

  14. Analysis of the stability of PTW riders in autonomous braking scenarios.

    Science.gov (United States)

    Symeonidis, Ioannis; Kavadarli, Gueven; Erich, Schuller; Graw, Matthias; Peldschus, Steffen

    2012-11-01

    While fatalities of car occupants in the EU decreased remarkably over the last decade, Powered Two Wheelers (PTWs) fatalities still increase following the increase of PTW ownership. Autonomous braking systems have been implemented in several types of vehicles and are presently addressed by research in the field of PTWs. A major concern in this context is the rider stability. Experiments with volunteers were performed in order to find out whether autonomous braking for PTWs will produce a greater instability of the rider in comparison to manual braking. The PTW's braking conditions were simulated in a laboratory with a motorcycle mock-up mounted on a sled, which was accelerated with an average of 0.35 g. The motion of the rider was captured in autonomous braking scenarios with and without pre-warning as well as in manual braking scenarios. No significant differences between the scenarios were found with respect to maximum forward displacement of the volunteer's torso and head (pautonomous braking at low deceleration will not cause significant instabilities of the rider in comparison to manual braking in idealized laboratory conditions. Based on this, further research into the development and implementation of autonomous braking systems for PTWs, e.g. by extensive riding tests, seems valuable. PMID:23036398

  15. Gravitational wave emission by the high braking index pulsar PSR J1640-4631

    CERN Document Server

    de Araujo, José C N; Costa, César A

    2016-01-01

    Recently, a braking index for the pulsar PSR J1640-4631 has been measured. With a braking index of $n = 3.15 \\pm 0.03$, this pulsar has the highest braking index ever measured. As it is well known, a pure magnetic dipole brake yields $n = 3$, whereas a pure gravitational wave brake yields $n = 5$. Therefore, each of these mechanisms alone can not account for the braking index found for PSR J1640-4631. Here we show that such a braking index can be accounted for if the spindown model combines magnetic dipole and gravitational wave brakes. Then, we briefly discuss the detectability of this pulsar by aLIGO and the planned Einstein Telescope. In particular, we show that the amplitude of the gravitational wave that comes from our model is around a factor four lower than the amplitude modeled exclusively by gravitational wave energy loss. Another interesting outcome of our modeling is that we are able to obtain the ellipticity from the braking index and other pulsar parameters.

  16. Real-Time Dynamic Brake Assessment Proof of Concept Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Lascurain, Mary Beth [ORNL; Franzese, Oscar [ORNL; Capps, Gary J [ORNL

    2011-11-01

    This proof-of-concept research was performed to explore the feasibility of using real-world braking data from commercial motor vehicles to make a diagnosis of brake condition similar to that of the performance-based brake tester (PBBT). This was done by determining the relationship between pressure and brake force (P-BF), compensating for the gross vehicle weight (GVW). The nature of this P-BF relationship (e.g., low braking force for a given brake application pressure) may indicate brake system problems. In order to determine the relationship between brake force and brake application pressure, a few key parameters of duty cycle information were collected. Because braking events are often brief, spanning only a few seconds, a sample rate of 10 Hz was needed. The algorithm under development required brake application pressure and speed (from which deceleration was calculated). Accurate weight estimation was also needed to properly derive the braking force from the deceleration. In order to ensure that braking force was the predominant factor in deceleration for the segments of data used in analysis, the data was screened for grade as well. Also, the analysis needed to be based on pressures above the crack pressure. The crack pressure is the pressure below which the individual brakes are not applied due the nature of the mechanical system. This value, which may vary somewhat from one wheel end to another, is approximately 10 psi. Therefore, only pressures 15 psi and above were used in the analysis. The Department of Energy s Medium Truck Duty Cycle research has indicated that under the real-world circumstances of the test vehicle brake pressures of up to approximately 30 psi can be expected. Several different types of data were collected during the testing task of this project. Constant-pressure stopping tests were conducted at several combinations of brake application pressure (15, 20, 25, and 30 psi), load conditions (moderately and fully laden), and speeds (20 and

  17. 重载列车制动管路对制动性能的影响%Influence of braking pipe on braking performance for heavy haul train

    Institute of Scientific and Technical Information of China (English)

    魏伟; 杜念博

    2011-01-01

    应用流体动力学理论,建立了重载列车制动管路模型与分配阀模型,求解了制动管路和边界点的动力学方程,仿真计算了制动过程中的制动系统性能,分析了列车主管和支管长度对制动系统性能的影响。分析结果表明:当列车主管长度由13.24 m增大为17.24 m时,在常用制动下,列车管路减压时间增大了30.75%,制动缸升压时间增大了20.45%,主管长度对常用制动的影响要强于对紧急制动的影响;当列车支管长度由0.50 m增大到5.00 m时,在常用制动下,列车管路减压时间增大了6.63%,制动缸升压时间增大了5.22%,支管长度对常用制动和紧急制动影响程度差别不大。列车制动管路长度增大降低了列车制动管路减压速度与制动缸升压速度;列车主管长度对制动性能的影响要明显大于列车支管长度的影响,车辆位置距机车越远影响越明显。%With fluid dynamics theory,the models of braking pipe and distributing valve for heavy haul train were built,the equations of braking pipe and boundary point were solved,the braking system performances in braking process were simulated,and the influence of the lengths of main pipe and branch pipe on the braking performances was analyzed.Analysis result shows that under common braking,when the length of main pipe increases from 13.24 m to 17.24 m,the decompression time of braking pipe increases by 30.75%,and the boost time of braking cylinder increases by 20.45%.The influence of main pipe on common braking is even stronger than that of main pipe on emergency braking.Under common braking,when the length of branch pipe increases from 0.50 m to 5.00 m,the decompression time of braking pipe increases by 6.63%,and the boost time of braking cylinder increases by 5.22%.The influence of branch pipe on common braking is almost same for that of branch pipe on emergency braking.The increase length of braking pipe reduces the decompression speed of braking pipe

  18. Effect of comfort pads and incubator design on neonatal radiography

    International Nuclear Information System (INIS)

    There has been increasing interest in patient dose reduction in neonatal intensive care units. Removing comfort pads for radiography has been identified as a potential means to decrease patient dose. To assess the effect of comfort pads and support trays on detector entrance exposure (DEE) and image quality for neonatal radiography, and its implication for patient dose. Comfort pads and support trays from three incubator and warmer systems were examined. The attenuation of the primary beam by these structures was measured using a narrow beam geometry. Their effect on DEE and image quality was then assessed using typical neonatal chest radiography techniques with three configurations: (1) both the comfort pad and support included in the beam, (2) only the support tray included and (3) both the comfort pad and support tray removed. Comfort pads and support trays were found to attenuate the primary beam by 6-15%. Eliminating these structures from the X-ray beam's path was found to increase the detector entrance exposure by 28-36% and increase contrast-to-noise ratio by more than 21%, suggesting room for patient dose reduction when the same image quality is maintained. Comfort pads and tray support devices can have a considerable effect on DEE and image quality, with large variations among different incubator designs. Positioning the image detector directly underneath neonatal patients for radiography is a potential means for patient dose reduction. However, such benefit should be weighed against the risks of moving the patient. (orig.)

  19. Heel pad avulsion injury: an approach with hyperbaric oxygen therapy

    Directory of Open Access Journals (Sweden)

    Pradeoth Korambayil Mukundan

    2015-04-01

    Full Text Available Aim: Crush injuries of the foot are often associated with partial or complete degloving of the heel pad. The purpose of this study is to present an algorithm for the management of various types of heel pad avulsion injuries, including hyperbaric oxygen (HBO therapy in the treatment regimen. Methods: We present a prospective study of 27 patients with various types of heel pad avulsion managed in our institution from December 2012 to June 2013. Heel pad avulsion injuries were classified according to the angiosomal pattern. Partial or complete avulsions were classified and treated accordingly. HBO therapy was administered postoperatively. The postoperative period, hospital course, and follow-up were documented in patients with heel pad avulsion injuries. Results: Of 27 patients, 20 cases presented with partial avulsion and 7 cases were complete avulsion. Of 20 cases of partial avulsion, one of the flaps was anchored with K-wire. Nineteen cases of partial heel pad avulsion were managed by suturing. Eight patients out of 20 required skin grafting as a secondary procedure at a later date. Out of 7 cases of complete avulsion, one was managed by full-thickness skin grafting, one case by reverse sural artery flap coverage, and four cases were managed by free tissue transfer. No flap revisions were required, and no complications were experienced for the transferred flaps. Conclusion: HBO therapy may be a useful adjunct in the treatment of heel pad avulsion injuries.

  20. Effect of comfort pads and incubator design on neonatal radiography

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Xia; Baad, Michael; Reiser, Ingrid; Feinstein, Kate A.; Lu, Zhengfeng [University of Chicago Medicine, Department of Radiology, Chicago, IL (United States)

    2016-01-15

    There has been increasing interest in patient dose reduction in neonatal intensive care units. Removing comfort pads for radiography has been identified as a potential means to decrease patient dose. To assess the effect of comfort pads and support trays on detector entrance exposure (DEE) and image quality for neonatal radiography, and its implication for patient dose. Comfort pads and support trays from three incubator and warmer systems were examined. The attenuation of the primary beam by these structures was measured using a narrow beam geometry. Their effect on DEE and image quality was then assessed using typical neonatal chest radiography techniques with three configurations: (1) both the comfort pad and support included in the beam, (2) only the support tray included and (3) both the comfort pad and support tray removed. Comfort pads and support trays were found to attenuate the primary beam by 6-15%. Eliminating these structures from the X-ray beam's path was found to increase the detector entrance exposure by 28-36% and increase contrast-to-noise ratio by more than 21%, suggesting room for patient dose reduction when the same image quality is maintained. Comfort pads and tray support devices can have a considerable effect on DEE and image quality, with large variations among different incubator designs. Positioning the image detector directly underneath neonatal patients for radiography is a potential means for patient dose reduction. However, such benefit should be weighed against the risks of moving the patient. (orig.)

  1. Analysis of heat conduction in a drum brake system of the wheeled armored personnel carriers

    Science.gov (United States)

    Puncioiu, A. M.; Truta, M.; Vedinas, I.; Marinescu, M.; Vinturis, V.

    2015-11-01

    This paper is an integrated study performed over the Braking System of the Wheeled Armored Personnel Carriers. It mainly aims to analyze the heat transfer process which is present in almost any industrial and natural process. The vehicle drum brake systems can generate extremely high temperatures under high but short duration braking loads or under relatively light but continuous braking. For the proper conduct of the special vehicles mission in rough terrain, we are talking about, on one hand, the importance of the possibility of immobilization and retaining position and, on the other hand, during the braking process, the importance movement stability and reversibility or reversibility, to an encounter with an obstacle. Heat transfer processes influence the performance of the braking system. In the braking phase, kinetic energy transforms into thermal energy resulting in intense heating and high temperature states of analyzed vehicle wheels. In the present work a finite element model for the temperature distribution in a brake drum is developed, by employing commercial finite element software, ANSYS. These structural and thermal FEA models will simulate entire braking event. The heat generated during braking causes distortion which modifies thermoelastic contact pressure distribution drum-shoe interface. In order to capture the effect of heat, a transient thermal analysis is performed in order to predict the temperature distribution transitional brake components. Drum brakes are checked both mechanical and thermal. These tests aim to establish their sustainability in terms of wear and the variation coefficient of friction between the friction surfaces with increasing temperature. Modeling using simulation programs led eventually to the establishment of actual thermal load of the mechanism of brake components. It was drawn the efficiency characteristic by plotting the coefficient of effectiveness relative to the coefficient of friction shoe-drum. Thus induced

  2. THE EFFECT OF FOOTBALL SHOULDER PADS ON PULMONARY FUNCTION

    Directory of Open Access Journals (Sweden)

    J. Richard Coast

    2005-12-01

    Full Text Available Restriction of expansion of the lungs or chest wall impedes inflation of the lungs during inhalation. Functional changes occurring during such restriction include reduced pulmonary and/or chest wall compliance, decreases in pulmonary function, and ultimately a decrease in exercise performance. Such restriction can be seen in several pathologic conditions such as scoliosis or obesity, as well as occupational situations such as the wearing of bullet-proof vests. This study investigated the hypothesis that tightened football shoulder pads produce decrements in pulmonary function similar to those shown in previous studies involving other external chest-wall restricting devices. In this study, 24 subjects, all members of a collegiate division IAA football team and used to wearing the pads, performed standard pulmonary function tests while wearing no pads (control, CTRL, wearing pads that were not secured (pads loose, PL and while wearing pads secured "game-tight" (pads tight, PT. The data showed that both forced vital capacity (FVC and forced expiratory volume in one second (FEV1.0 were significantly decreased in the PT condition compared to either the CTRL or PL condition, with no changes in the FEV1.0/FVC ratio or peak expiratory flow rate. These results are consistent with a restrictive condition and support our hypothesis that tightened shoulder pads reduce pulmonary function. Further studies remain to be performed to determine whether these changes lead to decreased exercise performance and whether equipment modifications can be made to limit alterations in pulmonary function without decreasing the protective value of the pads.

  3. Diagnostic accuracy of heel pad palpation - A phantom study

    DEFF Research Database (Denmark)

    Torp-Pedersen, Søren; Matteoli, Sara; Wilhjelm, Jens E.; Amris, K.; Bech, Jakob Ilsted; Christensen, R; Danneskiold-Samsøe, B.

    2008-01-01

    Falanga torture involves repetitive blunt trauma to the soles of the feet and typically leaves few detectable changes. Reduced elasticity in the heel pads has been reported as characteristic sequelae and palpatory testing of heel pad elasticity is therefore part of medicolegal assessment of alleged...... torture victims. The goal was to test the accuracy of two experienced investigators in determining whether a heel pad model was soft, medium or hard. The skin-to-bone distance in the models varied within the human range....

  4. Mechanical behaviour of the heel pad: experimental and numerical approach

    DEFF Research Database (Denmark)

    Matteoli, Sara; Fontanella, C. G.; Virga, A.; Wilhjelm, Jens E.; Corvi, A.; Natali, A. N.

    The aim of the present work was to investigate the stress relaxation phenomena of the heel pad region under different loading conditions. A 31-year-old healthy female was enrolled in this study and her left foot underwent both MRI and experimental compression tests. Experimental results were...... compared with those obtained from finite element analysis performed on numerical 3D subject-specific heel pad model built on the basis of MRI. The calcaneal fat pad tissue was described with a visco-hyperelastic model, while a fiber-reinforced hyperelastic model was formulated for the skin. The reliability...

  5. Stability of multi orifice active tilting-pad journal bearings

    DEFF Research Database (Denmark)

    Haugaard, Asger M.; Santos, Ilmar

    2010-01-01

    The stability properties of actively lubricated tilting-pad journal bearings are investigated theoretically. The bearing preload factor and control system gains are varied, and stable and unstable regions are identified. It is seen, that the control system influences bearing stability, and that the...... nature and magnitude of this influence depends on the rotor mass, preload factor and rotational speed. Furthermore, it is shown that assuming the bearing pads to be rigid can produce a substantial error. A rigid pad model will overpredict the stable range of the bearing, thus it may lead to failure if...

  6. Teach yourself visually the new iPad

    CERN Document Server

    Watson, Lonzell

    2012-01-01

    A new edition of a bestseller, fully updated on the latest features of the iPad! The evolution of the iPad continues to deliver amazing possibilities, which is exactly why this bestselling guide evolves right along with it! Fully updated with coverage on the latest generation of the iPad, this full-color, step-by-step guide is perfectly suited for anyone who is a visual learner and learns best by visual cues and a tactile interface. You'll learn to access and download books, apps, music, and video content as well as send photos and emails, sync with other devices and services, and confidently

  7. Elastic modulus of tree frog adhesive toe pads

    OpenAIRE

    Barnes, W. Jon. P.; Goodwyn, Pablo J. Perez; Nokhbatolfoghahai, Mohsen; Gorb, Stanislav N.

    2011-01-01

    Previous work using an atomic force microscope in nanoindenter mode indicated that the outer, 10- to 15-μm thick, keratinised layer of tree frog toe pads has a modulus of elasticity equivalent to silicone rubber (5–15 MPa) (Scholz et al. 2009), but gave no information on the physical properties of deeper structures. In this study, micro-indentation is used to measure the stiffness of whole toe pads of the tree frog, Litoria caerulea. We show here that tree frog toe pads are amongst the softes...

  8. The Pad HPD as photodetector of the LHCb RICH detectors

    CERN Document Server

    Braem, André; Filthaut, F; Go, A; Joram, C; Séguinot, Jacques; Weilhammer, Peter; Ypsilantis, Thomas

    2001-01-01

    This document is a proposal to equip the LHCb RICH detectors with Pad HPDs as photodetectors. The Pad HPD has been developed "in-house" at CERN. It is a five inch vacuum tube with bialkali cathode and segmented silicon anode, incorporating 2048 anode pads, each connected to analogue readout electronics, encapsulated within the vacuum envelope. The design of the baseline option is described. Results of R&D using measurements in laboratory and test beam are described. The future R&D programme and the detector costs and production schedule are outlined.

  9. Exploring the use of iPads in Danish schools

    DEFF Research Database (Denmark)

    Khalid, Md. Saifuddin; Jurisic, Olivera; Kristensen, Henrik Stein;

    2014-01-01

    Mobile devices, especially the integration and adoption of iPads in school classrooms, is gaining emphasis across the research and development forums of academic, policy, organizational, political, and public spheres. In April 2012, the Danish government announced that they would allocate DKK 500...... of integrating and adopting desktop computers and other educational technologies. However, there are some unique advantages that iPad and other mobile devices can enable through apps, readiness, etc. Policies and strategies should be adopted to combine training and maintenance along with ensuring access to iPads....

  10. Spindown of Isolated Neutron Stars: Gravitational Waves or Magnetic Braking?

    OpenAIRE

    Staff, Jan; Jaikumar, Prashanth; Chan, Vincent; Ouyed, Rachid

    2011-01-01

    We study the spindown of isolated neutron stars from initially rapid rotation rates, driven by two factors: (i) gravitational wave emission due to r-modes and (ii) magnetic braking. In the context of isolated neutron stars, we present the first study including self-consistently the magnetic damping of r-modes in the spin evolution. We track the spin evolution employing the RNS code, which accounts for the rotating structure of neutron stars for various equations of state. We find that, despit...

  11. MAGNETIC BRAKING AND FIELD DISSIPATION IN THE PROTOSTELLAR ACCRETION PHASE

    Directory of Open Access Journals (Sweden)

    D. Galli

    2009-01-01

    Full Text Available We summarize recent theoretical work addressing the role of magnetic elds in the process of star formation. First, we concentrate on the efficiency of magnetic braking during cloud collapse and its consequences on the formation of centrifugally supported disks around young stars. Then, we relate this issue to the well-known magnetic ux problem of star formation, and we show that the introduction of non-ideal MHD e ects is a necessary step toward the development of self-consistent models for the collapse of molecular clouds and the formation and evolution of accretion disks around young stars.

  12. Big brake singularity is accommodated as an exotic quintessence field

    OpenAIRE

    Chimento, Luis P.; Richarte, Martín G.

    2015-01-01

    We describe a big brake singularity in terms of a modified Chaplygin gas equation of state $p=(\\ga_{m}-1)\\rho+\\al\\ga_{m}\\rho^{-n}$, accommodate this late-time event as an exotic quintessence model obtained from an energy-momentum tensor, and focus on the cosmological behavior of the exotic field, its kinetic energy and the potential energy. At the background level, the exotic field does not blow up whereas its kinetic energy and potential both grow without limit near the future singularity. W...

  13. Dynamic Braking System of a Tidal Generator: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Muljadi, Eduard; Wright, Alan; Gevorgian, Vahan; Donegan, James; Marnagh, Cian; McEntee, Jarlath

    2016-08-01

    Renewable energy generation has experienced significant cost reductions during the past decades, and it has become more accepted by the global population. In the beginning, wind generation dominated the development and deployment of renewable energy; however, during recent decades, photovoltaic (PV) generation has grown at a very significant pace due to the tremendous decrease in the cost of PV modules. The focus on renewable energy generation has now expanded to include new types with promising future applications, such as river and tidal generation. The input water flow to these types of resources is more predictable than wind or solar generation. The data used in this paper is representative of a typical river or tidal generator. The analysis is based on a generator with a power rating of 40 kW. The tidal generator under consideration is driven by two sets of helical turbines connected to each side of the generator located in between the turbines. The generator is operated in variable speed, and it is controlled to maximize the energy harvested as well as the operation of the turbine generator. The electrical system consists of a three-phase permanent magnet generator connected to a three-phase passive rectifier. The output of the rectifier is connected to a DC-DC converter to match the rectifier output to the DC bus voltage of the DC-AC inverter. The three-phase inverter is connected to the grid, and it is controlled to provide a good interface with the grid. One important aspect of river and tidal generation is the braking mechanism. In a tidal generator, the braking mechanism is important to avoid a runaway condition in case the connection to the grid is lost when there is a fault in the lines. A runaway condition may lead to an overspeed condition and cause extreme stresses on the turbine blade structure and eventual disintegration of the mechanical structure. In this paper, the concept of the dynamic braking system is developed and investigated for normal

  14. Dynamic Control Applied to a Laboratory Antilock Braking System

    Directory of Open Access Journals (Sweden)

    Cuauhtémoc Acosta Lúa

    2015-01-01

    Full Text Available The control of an antilock braking system is a difficult problem due to the existence of nonlinear dynamics and uncertainties of its characteristics. To overcome these issues, in this work, a dynamic nonlinear controller is proposed, based on a nonlinear observer. To evaluate its performance, this controller has been implemented on an ABS Laboratory setup, representing a quarter car model. The nonlinear observer reconstructs some of the state variables of the setup, assumed not measurable, to establish a fair benchmark for an ABS system of a real automobile. The dynamic controller ensures exponential convergence of the state estimation, as well as robustness with respect to parameter variations.

  15. Parameter Analysis on Torque Stabilization for the Eddy Current Brake: A Developed Model, Simulation, and Sensitive Analysis

    OpenAIRE

    Quan Zhou; Xuexun Guo; Gangfeng Tan; Xiaomeng Shen; Yifan Ye; Zhaohua Wang

    2015-01-01

    Eddy current brake (ECB) is an attractive contactless brake whereas it suffers from braking torque attenuation when the rotating speed increases. To stabilize the ECB’s torque generation property, this paper introduces the concept of anti-magneto-motive force to develop the ECB model on the fundamental of magnetic circles. In the developed model, the eddy current demagnetization and the influence of temperature which make the braking torque attenuation are clearly presented. Using the develop...

  16. Comparing Variability of Parameters between Roller Bed Brakes Testers and Dynamometric Platform of Ministry Of Transport Facilities

    Directory of Open Access Journals (Sweden)

    Senabre C

    2015-01-01

    Full Text Available This study gives a comparison between which parameters may vary when braking on two different Ministry of Transport (MOT brake testers, such as roller bed brake tester and dynamometric platform. A comparative study between both types of brake testers have been carried out by the mechanical engineering staffs at the mechanical laboratory at the Miguel Hernández University in Elche to determinate which parameters can vary the result of the test.

  17. Energy-Regenerative Braking Control of Electric Vehicles Using Three-Phase Brushless Direct-Current Motors

    OpenAIRE

    Bo Long; Shin Teak Lim; Ji Hyoung Ryu; Kil To Chong

    2013-01-01

    Regenerative braking provides an effective way of extending the driving range of battery powered electric vehicles (EVs). This paper analyzes the equivalent power circuit and operation principles of an EV using regenerative braking control technology. During the braking period, the switching sequence of the power converter is controlled to inverse the output torque of the three-phase brushless direct-current (DC) motor, so that the braking energy can be returned to the battery. Compared with ...

  18. Pericruciate fat pad of the knee: anatomy and pericruciate fat pad inflammation: cadaveric and clinical study emphasizing MR imaging

    International Nuclear Information System (INIS)

    The pericruciate fat pad is located in the intercondylar fossa, intimate with the cruciate ligaments. With MR imaging, signal abnormality of the pericruciate fat pad has been observed in patients with posterior knee pain. The purpose of this study was to describe the anatomy of the pericruciate fat pad in cadaveric specimens and to document the clinical spectrum of pericruciate fat pad inflammation. Twelve cadaveric knees underwent MR imaging with T1 and T2 multiplanar images. Cadaveric sections were then prepared for macroscopic evaluation, with additional histologic analysis performed in four cases. MR images in seventeen patients (ten males, seven females; average age, 31.5 years; age range, 19-57 years) involved in intensive sporting activity and with posterior knee pain were reviewed. MR images in cadaveric specimens showed a fat pad that was located above and between the cruciate ligaments, near their attachment sites in the inner portion of the femoral condyles, within the intercondylar fossa. Fatty tissue covered by a thin layer of synovial membrane was confirmed at histology. Seventeen patients with posterior knee pain and without gross cartilage, meniscal, or ligamentous abnormalities all revealed an increased signal in this fat pad in fluid-sensitive fat-suppressed images, mainly in the sagittal and axial planes. In eight cases, enhancement of this fat pad was demonstrated following intravenous gadolinium administration. The pericruciate fat pad is a structure located in the intercondylar fossa, intimate with both the anterior and posterior cruciate ligaments. Inflammatory changes in this fat pad may be found in patients, especially athletes with posterior knee pain. (orig.)

  19. Pericruciate fat pad of the knee: anatomy and pericruciate fat pad inflammation: cadaveric and clinical study emphasizing MR imaging

    Energy Technology Data Exchange (ETDEWEB)

    Skaf, Abdalla Youssef [Hospital do Coracao (HCor), Department of Radiology, Sao Paulo, SP (Brazil); Hernandez Filho, Guinel [Santa Casa de Sao Paulo Hospital, Department of Radiology, Sao Paulo, SP (Brazil); Dirim, Berna [Izmir Atatuerk Training and Research Hospital, Department of Radiology, Karsiyaka, izmir (Turkey); Wangwinyuvirat, Mani [Rajavithi Hospital, Department of Radiology, Bangkok (Thailand); Trudell, Debra; Resnick, Donald [University of California, San Diego, Department of Radiology, Veterans Affairs Medical Center, La Jolla, CA (United States); Haghigi, Parvitz [University of California, San Diego, Department of Pathology, Veterans Affairs Medical Center, La Jolla, CA (United States)

    2012-12-15

    The pericruciate fat pad is located in the intercondylar fossa, intimate with the cruciate ligaments. With MR imaging, signal abnormality of the pericruciate fat pad has been observed in patients with posterior knee pain. The purpose of this study was to describe the anatomy of the pericruciate fat pad in cadaveric specimens and to document the clinical spectrum of pericruciate fat pad inflammation. Twelve cadaveric knees underwent MR imaging with T1 and T2 multiplanar images. Cadaveric sections were then prepared for macroscopic evaluation, with additional histologic analysis performed in four cases. MR images in seventeen patients (ten males, seven females; average age, 31.5 years; age range, 19-57 years) involved in intensive sporting activity and with posterior knee pain were reviewed. MR images in cadaveric specimens showed a fat pad that was located above and between the cruciate ligaments, near their attachment sites in the inner portion of the femoral condyles, within the intercondylar fossa. Fatty tissue covered by a thin layer of synovial membrane was confirmed at histology. Seventeen patients with posterior knee pain and without gross cartilage, meniscal, or ligamentous abnormalities all revealed an increased signal in this fat pad in fluid-sensitive fat-suppressed images, mainly in the sagittal and axial planes. In eight cases, enhancement of this fat pad was demonstrated following intravenous gadolinium administration. The pericruciate fat pad is a structure located in the intercondylar fossa, intimate with both the anterior and posterior cruciate ligaments. Inflammatory changes in this fat pad may be found in patients, especially athletes with posterior knee pain. (orig.)

  20. Short term braking capability during power interruptions for integrated matrix converter

    DEFF Research Database (Denmark)

    Klumpner, Christian; Blaabjerg, Frede

    2004-01-01

    attractive. Sinusoidal input currents and bi-directional power flow are other advantages of the matrix converter, but it is less immune to power grid disturbances compared to a standard ASD. In hoisting applications, short-term braking capability during a power outage is needed until the mechanical brake...

  1. Evolution of the pulsar inclination angle in the wind braking model

    CERN Document Server

    Kou, F F; Wang, N

    2016-01-01

    In a plasma filled magnetosphere, in addition to providing a torque to brake down the pulsar, the magnetosphere will also generate a torque to align the pulsar magnetic and rotational axes. The evolution of pulsar inclination angle in the wind braking model is calculated. In the wind braking model, the oblique pulsar tends to align. The pulsar alignment will also affect the spin-down behavior. Braking index will increase firstly and then decrease as the pulsar evolving from the magneto-dipole radiation dominated case to the wind braking dominated case. Braking index may be larger than $3$ in the early time. And during the following long time, braking index will be always smaller than $3$. This can explain braking index observations of larger than $3$ and smaller than $3$. Besides, the pulsar will evolve downwards straightly to the death valley after pulsar death in the $P-\\dot{P}$ diagram. This may explain the observed maximum spinning period of pulsars. And the long-term evolution of pulsars in the wind brak...

  2. Solid state circuit controls direction, speed, and braking of dc motor

    Science.gov (United States)

    Hanna, M. F.

    1966-01-01

    Full-wave bridge rectifier circuit controls the direction, speed, and braking of a dc motor. Gating in the circuit of Silicon Controlled Rectifiers /SCRS/ controls output polarity and braking is provided by an SCR that is gated to short circuit the reverse voltage generated by reversal of motor rotation.

  3. 76 FR 44829 - Federal Motor Vehicle Safety Standards; Air Brake Systems

    Science.gov (United States)

    2011-07-27

    ... 6x4 tractor with a 190-inch wheelbase, equipped with a hybrid disc brake configuration. The vehicle... National Highway Traffic Safety Administration 49 CFR Part 571 RIN 2127-AK84 Federal Motor Vehicle Safety... published a final rule that amended the Federal motor vehicle safety standard for air brake systems...

  4. Brake wear from vehicles as an important source of diffuse copper pollution

    NARCIS (Netherlands)

    Hulskotte, J.H.J.; Gon, H.A.C.D. van der; Visschedijk, A.J.H.; Schaap, M.

    2007-01-01

    In this article we show that brake wear from road traffic vehicles is an important source of atmospheric (participate) copper concentrations in Europe. Consequently, brake wear also contributes significantly to deposition fluxes of copper to surface waters. We estimated the copper emission due to br

  5. 77 FR 39561 - Advanced Braking Technologies That Rely on Forward-Looking Sensors; Request for Comments

    Science.gov (United States)

    2012-07-03

    ... Sensors; Request for Comments AGENCY: National Highway Traffic Safety Administration (NHTSA), Department... technologies that rely on forward-looking sensors to supplement driver braking or to actuate automatic braking... information from forward-looking sensors, usually a camera or radar, to determine whether or not a crash...

  6. Effect of Road Adhesion Coefficient on Tractor-Semitrailer Cornering Braking Stability

    Science.gov (United States)

    Wang, Wei; Li, Chen; Tang, Geteng; Wang, Cheng

    A dynamic model of tractor-semitrailer cornering braking was established in this paper, and the accuracy of the model was verified by real vehicle test. By model simulation of the cornering braking process, different road adhesion coefficient such as 0.15, 0.3, 0.45, 0.6, 0.75 was chosen to analyzed the changing curve of braking distance, articulation angle, yaw rate and lateral acceleration when initial speed of tractor-semitrailer was 30km h. The result showed that the peak values of articulation angle, yaw rate and lateral acceleration gotten by simulation were the largest. On the road of road adhesion coefficient 0.15, distance of tractor-semitrailer cornering braking was the longest. On the road of road adhesion coefficient 0.75, distance of tractor-semitrailer cornering braking was the shortest and the peak values of articulation angle, yaw rate and lateral acceleration were small relatively.

  7. Investigation of Friction Behaviors of Brake Shoe Materials using Metallic Filler

    Directory of Open Access Journals (Sweden)

    E. Surojo

    2015-12-01

    Full Text Available Some vehicles use brake shoe made from semi-metallic materials. Semi-metallic brake shoes are made from a combination of metallic and non-metallic materials. Metallic particles are added in the formulation of brake shoe material to improve composites characteristics. In this paper, friction behaviors of brake shoe material using metallic filler were investigated. Machining chips of cast iron and copper wire of electric motor used were incorporated in composite as metallic fillers with amount 0, 2, and 4 vol. %. Friction testing was performed to measure coefficient of friction by pressing surface specimen against the surface of rotating disc. The results show that cast iron chip and Cu short wire have effect on increasing coefficient of friction of brake shoe material. They form contact plateau at contact surface. At contact surface, the Cu short wires which have parallel orientation to the sliding contact were susceptible to detach from the matrix.

  8. Experimental investigation of passive auto depressurization system (PADS) for AHWR

    International Nuclear Information System (INIS)

    Recently work has been initiated on a novel passive safety system named Passive Auto Depressurization System (PADS) for AHWR. In case of small break LOCA, RELAP analysis indicate that with reactor shutdown condition and accumulator available, even after long time Main Heat Transport (MHT) pressure does not fall to 2 bar i.e. the required condition of water injection from GDWP. The unavailability of GDWP injection may lead to rise in fuel clad temperature due to insufficient MHT coolant inventory. This situation calls for faster depressurization of MHT system which is achieved by PADS. The successful design, fabrication, installation and commissioning of experimental facility provides an important platform for design validation and demonstration of PADS mechanism for AHWR. The experimental results will be used for design optimization of PPPT, validation of RELAP results and for understanding the transient behavior of PADS for AHWR

  9. Review of Tour of the Nile [iPad App

    Directory of Open Access Journals (Sweden)

    Helen Strudwick

    2013-07-01

    Full Text Available A review of the iPad app, Tour of the Nile. The app promises 'a virtual journey along the Nile Valley' plus the chance to 'handle' objects through the technology of augmented reality.

  10. Accurate micro Hall effect measurements on scribe line pads

    DEFF Research Database (Denmark)

    Østerberg, Frederik Westergaard; Petersen, Dirch Hjorth; Wang, Fei;

    2009-01-01

    Hall mobility and sheet carrier density are important parameters to monitor in advanced semiconductor production. If micro Hall effect measurements are done on small pads in scribe lines, these parameters may be measured without using valuable test wafers. We report how Hall mobility can be extra......Hall mobility and sheet carrier density are important parameters to monitor in advanced semiconductor production. If micro Hall effect measurements are done on small pads in scribe lines, these parameters may be measured without using valuable test wafers. We report how Hall mobility can...... be extracted from micro four-point measurements performed on a rectangular pad. The dimension of the investigated pad is 400 × 430 ¿m2, and the probe pitches range from 20 ¿m to 50 ¿m. The Monte Carlo method is used to find the optimal way to perform the Hall measurement and extract Hall mobility most...

  11. Lily Pad: Towards Real-time Interactive Computational Fluid Dynamics

    CERN Document Server

    Weymouth, Gabriel D

    2015-01-01

    Despite the fact that computational fluid dynamics (CFD) software is now (relatively) fast and freely available, it is still amazingly difficult to use. Inaccessible software imposes a significant entry barrier on students and junior engineers, and even senior researchers spend less time developing insights and more time on software issues. Lily Pad was developed as an initial attempt to address some of these problems. The goal of Lily Pad is to lower the barrier to CFD by adopting simple high-speed methods, utilising modern programming features and environments, and giving immediate visual feed-back to the user. The resulting software focuses on the fluid dynamics instead of the computation, making it useful for both education and research. LilyPad is open source and available online at https://github.com/weymouth/lily-pad for all use under the MIT license.

  12. Design of the Electronic Brake Pressure Modulator Using a Direct Adaptive Fuzzy Controller in Commercial Vehicles for the Safety of Braking in Fail

    Science.gov (United States)

    Kim, Hunmo

    In the brake systems, it is important to reduce the rear brake pressure in order to secure the safety of the vehicle in braking. So, there was some research that reduced and controlled the rear brake pressure exactly like a L. S. P. V and a E. L. S. P. V. However, the previous research has some weaknesses: the L. S. P. V is a mechanical system and its brake efficiency is lower than the efficiency of E. L. S. P. V. But, the cost of E. L. S. P. V is very higher so its application to the vehicle is very difficult. Additionally, when a fail appears in the circuit which controls the valves, the fail results in some wrong operation of the valves. But, the previous researchers didn't take the effect of fail into account. Hence, the efficiency of them is low and the safety of the vehicle is not confirmed. So, in this paper we develop a new economical pressure modulator that exactly controls brake pressure and confirms the safety of the vehicle in any case using a direct adaptive fuzzy controller.

  13. Insect tricks: two-phasic foot pad secretion prevents slipping

    OpenAIRE

    Dirks, Jan-Henning; Clemente, Christofer J.; Federle, Walter

    2009-01-01

    Many insects cling to vertical and inverted surfaces with pads that adhere by nanometre-thin films of liquid secretion. This fluid is an emulsion, consisting of watery droplets in an oily continuous phase. The detailed function of its two-phasic nature has remained unclear. Here we show that the pad emulsion provides a mechanism that prevents insects from slipping on smooth substrates. We discovered that it is possible to manipulate the adhesive secretion in vivo using smooth polyimide substr...

  14. Method for Producing Launch/Landing Pads and Structures Project

    Science.gov (United States)

    Mueller, Robert P. (Compiler)

    2015-01-01

    Current plans for deep space exploration include building landing-launch pads capable of withstanding the rocket blast of much larger spacecraft that that of the Apollo days. The proposed concept will develop lightweight launch and landing pad materials from in-situ materials, utilizing regolith to produce controllable porous cast metallic foam brickstiles shapes. These shapes can be utilized to lay a landing launch platform, as a construction material or as more complex parts of mechanical assemblies.

  15. Synovial hemangioma in Hoffa's fat pad (case report).

    Science.gov (United States)

    Aynaci, O; Ahmetoğlu, A; Reis, A; Turhan, A U

    2001-11-01

    A 15-year-old girl presented with anterolateral knee pain for 6 months. There were tenderness and pain at the anterolateral triangulation of the knee joint. Magnetic resonance imaging revealed a tumor in the anterolateral corner of the knee joint. Arthroscopy did not show the tumor because it was located in fat pad. The tumor was found during fat pad shaving and was resected arthroscopically. Synovial hemangioma was demonstrated histologically. The patient is asymptomatic postoperatively. PMID:11734873

  16. Development of fly ash-based automotive brake lining

    Energy Technology Data Exchange (ETDEWEB)

    Mohanty, S.; Chugh, Y.P. [South Illinois University, Carbondale, IL (United States). College of Engineering

    2007-07-15

    Coal-fired power plants all over the world generate huge amounts of fly ash each year, 70 million tons of which are produced in the United States alone. Only 40% of all fly ashes generated in the USA find beneficial applications and rest have to be disposed off, which is burden for the generation industry. Fly ash particles possess certain characteristics that make them suitable for use in friction composites as a filter material. An attempt has been made through this research to incorporate more than 50wt% of fly ash particles in automotive brake lining friction composites. This paper presents the research carried out on development of friction composites, using fly ash obtained from a specific power plant in Illinois. Ingredients such as phenolic resin, aramid pulp, glass fiber, potassium titanate, graphite, aluminum fiber and copper powder were used in the composite development phase, in addition to the fly ash. The developed brake lining composites have exhibited consistent coefficients of friction in the range of 0.35-0.4, and wear rates lower than 12wt%.

  17. A nonextensive view of the stellar braking indices

    Science.gov (United States)

    de Freitas, D. B.; Cavalcante, F. J.; Soares, B. B.; Silva, J. R. P.

    2015-08-01

    The present work is based on the effects of the magnetic braking for the angular-mometum loss evolution and, consequently, the relationship between stellar rotation and age. In general, this loss rate denoted by {d}J/{d}t depends on the angular velocity Ω in the form {d}J/ {d}t\\proptoΩq , where q is a parameter from nonextensive statistical mechanics. In the context of the stellar rotation, this parameter is directly related to the braking index. For q equal to unity, the scenario of the saturation of the magnetic field is recovered. Such an approach was proposed and investigated by de Freitas and De Medeiros for unsaturated field stars. We propose a new nonextensive approach for the stellar rotational evolution based on the Reiners and Mohanty model. We developed a nonextensive version of Reiners and Mohanty torque, and compare it with the model proposed in de Freitas and De Medeiros, by using a sample of velocity v\\sin i for ∼16000 field F- and G- stars. As a result, we show that the Kawaler and Reiners-Mohanty models exhibit strong discrepancies in relation to the domain of validity of the entropic index q. These discrepancies are mainly due to sensitivity on the stellar radius. Our results also showed that the modified Kawaler prescription is consistent in a wider mass ranges, while the Reiners and Mohanty model is restricted to masses less than from G6 stars.

  18. Big brake singularity is accommodated as an exotic quintessence field

    Science.gov (United States)

    Chimento, Luis P.; Richarte, Martín G.

    2016-02-01

    We describe a big brake singularity in terms of a modified Chaplygin gas equation of state p =(γm-1 )ρ +α γmρ-n, accommodate this late-time event as an exotic quintessence model obtained from an energy-momentum tensor, and focus on the cosmological behavior of the exotic field, its kinetic energy, and the potential energy. At the background level the exotic field does not blow up, whereas its kinetic energy and potential both grow without limit near the future singularity. We evaluate the classical stability of this background solution by examining the scalar perturbations of the metric along with the inclusion of entropy perturbation in the perturbed pressure. Within the Newtonian gauge, the gravitational field approaches a constant near the singularity plus additional regular terms. When the perturbed exotic field is associated with α >0 the perturbed pressure and contrast density both diverge, whereas the perturbed exotic field and the divergence of the exotic field's velocity go to zero exponentially. When the perturbed exotic field is associated with α <0 the contrast density always blows up, but the perturbed pressure can remain bounded. In addition, the perturbed exotic field and the divergence of the exotic field's velocity vanish near the big brake singularity. We also briefly look at the behavior of the intrinsic entropy perturbation near the singular event.

  19. Structure Analysis at the Micro Iron Pour at Gray Brake

    Directory of Open Access Journals (Sweden)

    Melya D. Sebayang

    2012-01-01

    Full Text Available The use of gray cast iron brake drum as the material is the most appropriate choice, because it has properties which have good heat conductivity, hardness, toughness, good friction properties and the ability to absorb vibration. The purpose of this study to determine the ratio of the microstructure on both original material drum that is new and original drum ex-wear. With the aim of analysis is expected to be used as basis in planning the development of better vehicle brakes. Of all the test results it can be mentioned chemical composition of test results with the main alloying elements, to drum new original: C 4:13%, 2:51% Si, 0.15% S, 0.65% Mn, 0.0054% P, and the original drum ex-wear: C 4:13%, 2:17% Si, 0.15% S, 0.53% Mn, 0.0054% P. So the comparison of properties of the resulting structure after the testing process on each drum is the hardness and resistance to wear and tear on a new original drum better when compared with the original drum ex-wear.

  20. Digital Sliding Mode Control of Anti-Lock Braking System

    Directory of Open Access Journals (Sweden)

    MITIC, D. B.

    2013-02-01

    Full Text Available The control of anti-lock braking system is a great challenge, because of the nonlinear and complex characteristics of braking dynamics, unknown parameters of vehicle environment and system parameter variations. Using some of robust control methods, such as sliding mode control, can be a right solution for these problems. In this paper, we introduce a novel approach to design of ABS controllers, which is based on digital sliding mode control with only input/output measurements. The relay term of the proposed digital sliding mode control is filtered through digital integrator, reducing the chattering phenomenon in that way, and the additional signal of estimated modelling error is introduced into control algorithm to enhance the system steady-state accuracy. The given solution was verified in real experimental framework and the obtained results were compared with the results of implementation of two other digital sliding mode control algorithms. It is shown that it gives better system response, higher steady-state accuracy and smaller chattering.

  1. A nonextensive view of the stellar braking indices

    CERN Document Server

    de Freitas, D B; Soares, B B; Silva, J R P

    2015-01-01

    The present work is based on a description for the angular mometum loss rate due to magnetic braking for main-sequence stars on the relationship between stellar rotation and age. In general, this loss rate denoted by $\\mathrm dJ/\\mathrm dt$ depends on angular velocity $\\Omega$ in the form $\\mathrm dJ/\\mathrm dt\\propto\\Omega^{q}$, where $q$ is a parameter extracted from nonextensive statistical mechanics. Already, in context of stellar rotation, this parameter is greater than unity and it is directly related to the braking index. For $q$ equal to unity, the scenario of saturation of the magnetic field is recovered, otherwise $q$ indicates an unsaturated field. This new approach have been proposed and investigated by de Freitas \\& De Medeiros for unsaturated field stars. In present work, we propose a nonextensive approach for the stellar rotational evolution based on the Reiners \\& Mohanthy model. In this sense, we developed a nonextensive version of Reiners \\& Mohanthy torque and also compare this ...

  2. Can non-ideal magnetohydrodynamics solve the magnetic braking catastrophe?

    Science.gov (United States)

    Wurster, James; Price, Daniel J.; Bate, Matthew R.

    2016-03-01

    We investigate whether or not the low ionization fractions in molecular cloud cores can solve the `magnetic braking catastrophe', where magnetic fields prevent the formation of circumstellar discs around young stars. We perform three-dimensional smoothed particle non-ideal magnetohydrodynamics (MHD) simulations of the gravitational collapse of one solar mass molecular cloud cores, incorporating the effects of ambipolar diffusion, Ohmic resistivity and the Hall effect alongside a self-consistent calculation of the ionization chemistry assuming 0.1 μm grains. When including only ambipolar diffusion or Ohmic resistivity, discs do not form in the presence of strong magnetic fields, similar to the cases using ideal MHD. With the Hall effect included, disc formation depends on the direction of the magnetic field with respect to the rotation vector of the gas cloud. When the vectors are aligned, strong magnetic braking occurs and no disc is formed. When the vectors are anti-aligned, a disc with radius of 13 au can form even in strong magnetic when all three non-ideal terms are present, and a disc of 38 au can form when only the Hall effect is present; in both cases, a counter-rotating envelope forms around the first hydrostatic core. For weaker, anti-aligned fields, the Hall effect produces massive discs comparable to those produced in the absence of magnetic fields, suggesting that planet formation via gravitational instability may depend on the sign of the magnetic field in the precursor molecular cloud core.

  3. 21 CFR 884.5425 - Scented or scented deodorized menstrual pad.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Scented or scented deodorized menstrual pad. 884... Therapeutic Devices § 884.5425 Scented or scented deodorized menstrual pad. (a) Identification. A scented or scented deodorized menstrual pad is a device that is a pad made of cellulosic or synthetic material...

  4. Modeling of Tilting-Pad Journal Bearings with Transfer Functions

    Directory of Open Access Journals (Sweden)

    J. A. Vázquez

    2001-01-01

    Full Text Available Tilting-pad journal bearings are widely used to promote stability in modern rotating machinery. However, the dynamics associated with pad motion alters this stabilizing capacity depending on the operating speed of the machine and the bearing geometric parameters, particularly the bearing preload. In modeling the dynamics of the entire rotor-bearing system, the rotor is augmented with a model of the bearings. This model may explicitly include the pad degrees of freedom or may implicitly include them by using dynamic matrix reduction methods. The dynamic reduction models may be represented as a set of polynomials in the eigenvalues of the system used to determine stability. All tilting-pad bearings can then be represented by a fixed size matrix with polynomial elements interacting with the rotor. This paper presents a procedure to calculate the coefficients of polynomials for implicit bearing models. The order of the polynomials changes to reflect the number of pads in the bearings. This results in a very compact and computationally efficient method for fully including the dynamics of tilting-pad bearings or other multiple degrees of freedom components that interact with rotors. The fixed size of the dynamic reduction matrices permits the method to be easily incorporated into rotor dynamic stability codes. A recursive algorithm is developed and presented for calculating the coefficients of the polynomials. The method is applied to stability calculations for a model of a typical industrial compressor.

  5. The CIMSS iPad Library and ESIP Teacher Workshops

    Science.gov (United States)

    Dahlman, L.; Mooney, M. E.

    2012-12-01

    The Cooperative Institute for Meteorological Satellite Studies (CIMSS) at the University of Wisconsin-Madison launched a new initiative in 2012 to engage teachers and students in data acquisition and regional climate studies. The CIMSS iPad Library, part of a NASA funded Climate Literacy Ambassadors project, loans iPads to science teachers for an entire school year. The first units were distributed at a NOAA funded teacher workshop conducted at the annual Earth Science Information Partners (ESIP) summer conference. Educators learned about numerous NOAA and NASA resources at the ESIP Teacher Workshop and also several different climate-related Apps, including SatCam, an application for iOS devices that allows users to collect observations of local cloud and surface conditions coordinated with an overpass of the Terra, Aqua, or Suomi NPP satellite. This presentation will outline connections between the Climate Literacy Ambassadors community and ESIP Teacher Workshops before delving into details about the new iPad Library and SatCam. We will discuss considerations and challenges related to a technology loaning library, software recoding to HTML5, and some advantages and limitations related to iPads. We will also share feedback acquired over the fall from ESIP Educators using the SatCam App with their students with the iPads they borrowed (like books) from the CIMSS iPad Library.

  6. Proof Pad: A New Development Environment for ACL2

    Directory of Open Access Journals (Sweden)

    Caleb Eggensperger

    2013-04-01

    Full Text Available Most software development projects rely on Integrated Development Environments (IDEs based on the desktop paradigm, with an interactive, mouse-driven user interface. The standard installation of ACL2, on the other hand, is designed to work closely with Emacs. ACL2 experts, on the whole, like this mode of operation, but students and other new programmers who have learned to program with desktop IDEs often react negatively to the process of adapting to an unfamiliar form of interaction. This paper discusses Proof Pad, a new IDE for ACL2. Proof Pad is not the only attempt to provide ACL2 IDEs catering to students and beginning programmers. The ACL2 Sedan and DrACuLa systems arose from similar motivations. Proof Pad builds on the work of those systems, while also taking into account the unique workflow of the ACL2 theorem proving system. The design of Proof Pad incorporated user feedback from the outset, and that process continued through all stages of development. Feedback took the form of direct observation of users interacting with the IDE as well as questionnaires completed by users of Proof Pad and other ACL2 IDEs. The result is a streamlined interface and fast, responsive system that supports using ACL2 as a programming language and a theorem proving system. Proof Pad also provides a property-based testing environment with random data generation and automated interpretation of properties as ACL2 theorem definitions.

  7. Aircraft Conceptual Design Using Vehicle Sketch Pad

    Science.gov (United States)

    Fredericks, William J.; Antcliff, Kevin R.; Costa, Guillermo; Deshpande, Nachiket; Moore, Mark D.; Miguel, Edric A. San; Snyder, Alison N.

    2010-01-01

    Vehicle Sketch Pad (VSP) is a parametric geometry modeling tool that is intended for use in the conceptual design of aircraft. The intent of this software is to rapidly model aircraft configurations without expending the expertise and time that is typically required for modeling with traditional Computer Aided Design (CAD) packages. VSP accomplishes this by using parametrically defined components, such as a wing that is defined by span, area, sweep, taper ratio, thickness to cord, and so on. During this phase of frequent design builds, changes to the model can be rapidly visualized along with the internal volumetric layout. Using this geometry-based approach, parameters such as wetted areas and cord lengths can be easily extracted for rapid external performance analyses, such as a parasite drag buildup. At the completion of the conceptual design phase, VSP can export its geometry to higher fidelity tools. This geometry tool was developed by NASA and is freely available to U.S. companies and universities. It has become integral to conceptual design in the Aeronautics Systems Analysis Branch (ASAB) here at NASA Langley Research Center and is currently being used at over 100 universities, aerospace companies, and other government agencies. This paper focuses on the use of VSP in recent NASA conceptual design studies to facilitate geometry-centered design methodology. Such a process is shown to promote greater levels of creativity, more rapid assessment of critical design issues, and improved ability to quickly interact with higher order analyses. A number of VSP vehicle model examples are compared to CAD-based conceptual design, from a designer perspective; comparisons are also made of the time and expertise required to build the geometry representations as well.

  8. The effect of football shoulder pads on pulmonary function.

    Science.gov (United States)

    Coast, J Richard; Baronas, Jessica L; Morris, Colleen; Willeford, K Sean

    2005-12-01

    Restriction of expansion of the lungs or chest wall impedes inflation of the lungs during inhalation. Functional changes occurring during such restriction include reduced pulmonary and/or chest wall compliance, decreases in pulmonary function, and ultimately a decrease in exercise performance. Such restriction can be seen in several pathologic conditions such as scoliosis or obesity, as well as occupational situations such as the wearing of bullet-proof vests. This study investigated the hypothesis that tightened football shoulder pads produce decrements in pulmonary function similar to those shown in previous studies involving other external chest-wall restricting devices. In this study, 24 subjects, all members of a collegiate division IAA football team and used to wearing the pads, performed standard pulmonary function tests while wearing no pads (control, CTRL), wearing pads that were not secured (pads loose, PL) and while wearing pads secured "game-tight" (pads tight, PT). The data showed that both forced vital capacity (FVC) and forced expiratory volume in one second (FEV1.0) were significantly decreased in the PT condition compared to either the CTRL or PL condition, with no changes in the FEV1.0/FVC ratio or peak expiratory flow rate. These results are consistent with a restrictive condition and support our hypothesis that tightened shoulder pads reduce pulmonary function. Further studies remain to be performed to determine whether these changes lead to decreased exercise performance and whether equipment modifications can be made to limit alterations in pulmonary function without decreasing the protective value of the pads. Key PointsThe shoulder pads used in American football extend to the xyphoid process and may provide a restriction to breathing. This was tested in the present study in 24 college-level football players with normal resting pulmonary function.The results showed that there was a decrease in FVC of approximately 150 ml and a similar

  9. Geometrical design parameters for journal bearings with flexure pads and compliant liners

    DEFF Research Database (Denmark)

    Thomsen, Kim; Klit, Peder

    2012-01-01

    flexure pads. uidelines are given to the design of the pads and are also covering the polymer liner. It is found that the use of flexure pads is an attractive alternative to pivoted pads. Pivot contact-related failure modes are eliminated and load capacity is not restricted by the force that can be...... transferred through the pivot contact. When combined with a polymer liner, the pad performance is enhanced further, especially when operating at thin lubricant films....

  10. Optimal design of disc-type magneto-rheological brake for mid-sized motorcycle: experimental evaluation

    Science.gov (United States)

    Sohn, Jung Woo; Jeon, Juncheol; Nguyen, Quoc Hung; Choi, Seung-Bok

    2015-08-01

    In this paper, a disc-type magneto-rheological (MR) brake is designed for a mid-sized motorcycle and its performance is experimentally evaluated. The proposed MR brake consists of an outer housing, a rotating disc immersed in MR fluid, and a copper wire coiled around a bobbin to generate a magnetic field. The structural configuration of the MR brake is first presented with consideration of the installation space for the conventional hydraulic brake of a mid-sized motorcycle. The design parameters of the proposed MR brake are optimized to satisfy design requirements such as the braking torque, total mass of the MR brake, and cruising temperature caused by the magnetic-field friction of the MR fluid. In the optimization procedure, the braking torque is calculated based on the Herschel-Bulkley rheological model, which predicts MR fluid behavior well at high shear rate. An optimization tool based on finite element analysis is used to obtain the optimized dimensions of the MR brake. After manufacturing the MR brake, mechanical performances regarding the response time, braking torque and cruising temperature are experimentally evaluated.

  11. Interactive design optimization of magnetorheological-brake actuators using the Taguchi method

    International Nuclear Information System (INIS)

    This research explored an optimization method that would automate the process of designing a magnetorheological (MR)-brake but still keep the designer in the loop. MR-brakes apply resistive torque by increasing the viscosity of an MR fluid inside the brake. This electronically controllable brake can provide a very large torque-to-volume ratio, which is very desirable for an actuator. However, the design process is quite complex and time consuming due to many parameters. In this paper, we adapted the popular Taguchi method, widely used in manufacturing, to the problem of designing a complex MR-brake. Unlike other existing methods, this approach can automatically identify the dominant parameters of the design, which reduces the search space and the time it takes to find the best possible design. While automating the search for a solution, it also lets the designer see the dominant parameters and make choices to investigate only their interactions with the design output. The new method was applied for re-designing MR-brakes. It reduced the design time from a week or two down to a few minutes. Also, usability experiments indicated significantly better brake designs by novice users

  12. Modeling of automotive drum brakes for squeal and parameter sensitivity analysis

    Science.gov (United States)

    Huang, Jinchun; Krousgrill, Charles M.; Bajaj, Anil K.

    2006-01-01

    Many fundamental studies have been conducted to explain the occurrence of squeal in disc and drum brake systems. The elimination of brake squeal, however, still remains a challenging area of research. Here, a numerical modeling approach is developed for investigating the onset of squeal in a drum brake system. The brake system model is based on the modal information extracted from finite element models for individual brake components. The component models of drum and shoes are coupled by the shoe lining material which is modeled as springs located at the centroids of discretized drum and shoe interface elements. The developed multi degree of freedom coupled brake system model is a linear non-self-adjoint system. Its vibrational characteristics are determined by a complex eigenvalue analysis. The study shows that both the frequency separation between two system modes due to static coupling and their associated mode shapes play an important role in mode merging. Mode merging and veering are identified as two important features of modes exhibiting strong interactions, and those modes are likely candidates that lead to coupled-mode instability. Techniques are developed for a parameter sensitivity analysis with respect to lining stiffness and the stiffness of the brake actuation system. The influence of lining friction coefficient on the propensity to squeal is also discussed.

  13. Why do the braking indices of pulsars span over more than 100 millions?

    CERN Document Server

    Zhang, Shuang-Nan

    2012-01-01

    Here we report that the observed braking indices of the 366 pulsars in the sample of Hobbs et al. (2012) span from about $-10^8$ to about $+10^8$ and are significantly correlated with their characteristic ages. Using the model of magnetic field evolution we developed previously (Zhang & Xie 2012) based on the same data, we derived an analytical expression of the braking index, which agrees with all the observed statistical properties of the braking indices of the pulsars in the sample of Hobbs et al. (2012). Our model is, however, incompatible to the previous interpretation that the magnetic field growth is responsible for the observed small values of braking indices ($<3$) of "baby" pulsars with characteristic ages of less than $2\\times 10^3$ yr. We find that the "instantaneous" braking index of a pulsar may be different from the "averaged" braking index obtained from fitting the data over a certain time span. The close match between our model predicted "instantaneous" braking indices and the observed...

  14. Experimental Method for Analyzing Friction Phenomenon Related to Drum Brake Squeal

    Directory of Open Access Journals (Sweden)

    J. GLIŠOVIĆ

    2010-12-01

    Full Text Available Automobile brakes have been intensively developed during past few decades, but the maximum motor’s power, that should amortized in vehicle brakes, has been significantly increased also. Most of the kinetic energy of the moving vehicles is transforming into heat through friction. But the small part of kinetic energy transforms into sound pressure and makes noise. Low frequency squeal of drum brakes is very intense and can lead to customers’ complain. The interaction between the brake system and the vehicle framework and suspension is often very substantial during occurrence of brake noise. Unfortunately, to solve this type of squeal problem is also difficult because of the large number of components involved. The other cause is attributed to self-excited vibration that is induced when the friction material has a negative slope in relation to the relative velocity. This paper illustrates an approach to experimental studies of drum brakes in road conditions in order to monitor changes in the coefficient of friction that can generate drum brake squeal at low frequencies.

  15. Position control optimization of aerodynamic brake device for high-speed trains

    Science.gov (United States)

    Zuo, Jianyong; Luo, Zhuojun; Chen, Zhongkai

    2014-03-01

    The aerodynamic braking is a clean and non-adhesion braking, and can be used to provide extra braking force during high-speed emergency braking. The research of aerodynamic braking has attracted more and more attentions in recent years. However, most researchers in this field focus on aerodynamic effects and seldom on issues of position control of the aerodynamic braking board. The purpose of this paper is to explore position control optimization of the braking board in an aerodynamic braking prototype. The mathematical models of the hydraulic drive unit in the aerodynamic braking system are analyzed in detail, and the simulation models are established. Three control functions—constant, linear, and quadratic—are explored. Two kinds of criteria, including the position steady-state error and the acceleration of the piston rod, are used to evaluate system performance. Simulation results show that the position steady state-error is reduced from around 12-2 mm by applying a linear instead of a constant function, while the acceleration is reduced from 25.71-3.70 m/s2 with a quadratic control function. Use of the quadratic control function is shown to improve system performance. Experimental results obtained by measuring the position response of the piston rod on a test-bench also suggest a reduced position error and smooth movement of the piston rod. This implies that the acceleration is smaller when using the quadratic function, thus verifying the effectiveness of control schemes to improve to system performance. This paper proposes an effective and easily implemented control scheme that improves the position response of hydraulic cylinders during position control.

  16. Detection of visually unrecognizable braking tracks using Laser-Induced Breakdown Spectroscopy, a feasibility study

    Science.gov (United States)

    Prochazka, David; Bilík, Martin; Prochazková, Petra; Brada, Michal; Klus, Jakub; Pořízka, Pavel; Novotný, Jan; Novotný, Karel; Ticová, Barbora; Bradáč, Albert; Semela, Marek; Kaiser, Jozef

    2016-04-01

    Identification of the position, length and mainly beginning of a braking track has proven to be essential for determination of causes of a road traffic accident. With the introduction of modern safety braking systems and assistance systems such as the Anti-lock Braking System (ABS) or Electronic Stability Control (ESC), the visual identification of braking tracks that has been used up until the present is proving to be rather complicated or even impossible. This paper focuses on identification of braking tracks using a spectrochemical analysis of the road surface. Laser-Induced Breakdown Spectroscopy (LIBS) was selected as a method suitable for fast in-situ element detection. In the course of detailed observations of braking tracks it was determined that they consist of small particles of tire treads that are caught in intrusions in the road surface. As regards detection of the "dust" resulting from wear and tear of tire treads in the environment, organic zinc was selected as the identification element in the past. The content of zinc in tire treads has been seen to differ with regard to various sources and tire types; however, the arithmetic mean and modus of these values are approximately 1% by weight. For in-situ measurements of actual braking tracks a mobile LIBS device equipped with a special module was used. Several measurements were performed for 3 different cars and tire types respectively which slowed down with full braking power. Moreover, the influence of different initial speed, vehicle mass and braking track length on detected signal is discussed here.

  17. Short term Braking Capability during Power Interruptions for Integrated Matrix Converter-Motor Drives

    DEFF Research Database (Denmark)

    Klumpner, Christian; Blaabjerg, Frede

    2002-01-01

    The new trend in Adjustable Speed Drives (ASD) is to integrate the inverter and the motor into a single unit in order to reduce the production cost, the commissioning time and the physical size of the equipment. This last issue becomes more important, making the matrix converter topology more...... engages or to perform more effective a combined braking.This paper proposes a new method to provide short-term braking capability during a power outage for matrix converters. A braking chopper is needed in the clamp circuit, which allows for a drastically reduction of the capacitor size. The power flow in...

  18. Optimization of a parity of brake forces of automobiles in view of a bias of road

    International Nuclear Information System (INIS)

    In clause it is shown a method optimization of brake of forces in view of a bias road it is established, that in mountain conditions of loss of coupling weight of automobiles than 2-3 times concerning flat conditions therma are more. The degree of use of coupling weight in result use of a regulator of brake forces very much increases also efficiency of brake systems such a kind of automobiles is provided with definition of optimum factor of coupling at which value of loss of coupling weight is provided minimal

  19. The emergency braking module for an electronic copilot design and first results

    Energy Technology Data Exchange (ETDEWEB)

    Ameling, C.; Kirchner, A. [Univ. of the Federal Armed Forces Hamburg (Germany). Dept. of Mechanical Engineering

    2000-07-01

    This paper deals with design and development of an emergency braking module for an electronic copilot (ECP). ECP is used within an autonomous vehicle as a partial redundant system for vehicle control. ECP receives the necessary information about the positions and relative velocities of obstacles from various sources such as laserscanner or vision sensors. In the current stage of development the emergency breaking module computes, whether an object collides with the front of the vehicle. If the time-to-collision falls below the braking capacity an emergency braking is triggered. Experimental results show the capabilities of the system. (orig.)

  20. Braking indices of pulsars obtained in the presence of an effective force

    CERN Document Server

    Magalhaes, N S; Frajuca, C

    2016-01-01

    Braking indices of pulsars present a scientific challenge as their theoretical calculation is still an open problem. In this paper we report results of a study regarding such calculation which adapts the canonical model (which admits that pulsars are rotating magnetic dipoles) basically by introducing a compensating component in the energy conservation equation of the system. This component would correspond to an effective force that varies with the first power of the tangential velocity of the pulsar's crust. We test the proposed model using data available and predict braking indices values for different stars. We comment on the high braking index recently measured of the pulsar J1640-4631.

  1. Atmospheric testing of wind turbine trailing edge aerodynamic brakes

    Energy Technology Data Exchange (ETDEWEB)

    Miller, L.S. [Wichita State Univ., KS (United States); Migliore, P.G. [National Renewable Energy Lab., Golden, CO (United States); Quandt, G.A.

    1997-12-31

    An experimental investigation was conducted using an instrumented horizontal-axis wind turbine that incorporated variable span trailing-edge aerodynamic brakes. A primary goal was to directly compare study results with (infinite-span) wind tunnel data and to provide information on how to account for device span effects during turbine design or analysis. Comprehensive measurements were utilized to define effective changes in the aerodynamic coefficients, as a function of angle of attack and control deflection, for three device spans and configurations. Differences in the lift and drag behavior are most pronounced near stall and for device spans of less than 15%. Drag performance is affected only minimally (<70%) for 15% or larger span devices. Interestingly, aerodynamic controls with characteristic vents or openings appear most affected by span reductions and three-dimensional flow.

  2. A laboratory activity on the eddy current brake

    International Nuclear Information System (INIS)

    The aim of this paper is to introduce a simple and low-cost experimental setup that can be used to study the eddy current brake, which considers the motion of a sliding magnet on an inclined conducting plane in terms of basic physical principles. We present a set of quantitative experiments performed to study the influence of the geometrical and electromagnetic properties of the magnet on the magnetic drag force. This video-based experiment is ideal for the study of kinematic graphs and the application of Newton's laws. Video motion analysis software enables students to make precise measurements of the magnet's position at incremental times during its motion, thus allowing them to quantify electromagnetic induction phenomena. The equipment needed for this experiment and data collection software are present in most physics teaching laboratories or are inexpensive and available. (paper)

  3. A new multi-grid type MSGC with pad readout

    International Nuclear Information System (INIS)

    Recently, a new multi-grid type MSGC has been proposed. Between the anode and the cathode, additional grid strips are placed in this new type of MSGC. Gaps between these strips are chosen to be around 10 μm which assure efficient removal of surface charges which even do not need the lower surface resistivity and bare glass can be used up to 106 cps/mm2. Another feature of the MSGC is its high gain capability. Owing to the existence of other strips of lower potentials, the field strength around the opposing grid to the anode strip is not so high as conventional small gap detectors. Furthermore, the contribution of the surface streamer is greatly suppressed because the electric field parallel to the surface is screened by the intermediate grid electrodes. However, the existence of additional electrodes also screens all the electric field upper than the substrate and we cannot observe induced signals from backside of the substrate. To overcome the difficulty, we propose another signal readout method using patterning approach. Floating pads are placed close to the cathode strip on the surface of the M-MSGC and induced charges are read out via the pads. If the area of pads is sufficiently large and the positive charges are moving toward the pads, backside electrodes can sense the induced charge. Collected charges on the pads are leaked through the surface resistivity. The basic experiment has been performed and the readout of the position along the cathode strips is successfully ensured

  4. Insect tricks: two-phasic foot pad secretion prevents slipping.

    Science.gov (United States)

    Dirks, Jan-Henning; Clemente, Christofer J; Federle, Walter

    2010-04-01

    Many insects cling to vertical and inverted surfaces with pads that adhere by nanometre-thin films of liquid secretion. This fluid is an emulsion, consisting of watery droplets in an oily continuous phase. The detailed function of its two-phasic nature has remained unclear. Here we show that the pad emulsion provides a mechanism that prevents insects from slipping on smooth substrates. We discovered that it is possible to manipulate the adhesive secretion in vivo using smooth polyimide substrates that selectively absorb its watery component. While thick layers of polyimide spin-coated onto glass removed all visible hydrophilic droplets, thin coatings left the emulsion in its typical form. Force measurements of stick insect pads sliding on these substrates demonstrated that the reduction of the watery phase resulted in a significant decrease in friction forces. Artificial control pads made of polydimethylsiloxane showed no difference when tested on the same substrates, confirming that the effect is caused by the insects' fluid-based adhesive system. Our findings suggest that insect adhesive pads use emulsions with non-Newtonian properties, which may have been optimized by natural selection. Emulsions as adhesive secretions combine the benefits of 'wet' adhesion and resistance against shear forces. PMID:19755498

  5. Visible light active photocatalyst from recycled disposable heating pads

    Science.gov (United States)

    Lee, Meng-Chien; Wang, Chun-Yu; Chen, Che-Chin; Wang, Chih-Ming; Hsiao, Ta-Chih; Tsai, Din Ping

    2016-01-01

    Alpha-Fe2O3 (α-Fe2O3) is cheap and abundant and has potential to be a highly efficient photocatalyst for water splitting. According to the report, there are a huge amount of disposable heating pads being created every year, and the pads are used one time then thrown away. We found that the main product of used heating pads is α-Fe2O3. Here, we collect and purify the α-Fe2O3 powder in the used heating pads using low power consumption processes. It is shown that the recycled heating pads can be used as a cost-effective photocatalyst for H2 energy and for decomposition of organic pollutants as well. Additionally, the plasmonic enhanced photocatalysis reaction of α-Fe2O3 is also investigated. It is found that H2 evolution rate can be enhanced 15% using α-Fe2O3 nanoparticles coated with a thin Au layer. The degradation of methylene blue can also enhance 12% compared to photocatalyst α-Fe2O3 nanoparticles coated without Au layer.

  6. iPads betydning for studerendes læring

    DEFF Research Database (Denmark)

    Bisgaard, Kirsten; Melander, Thomas; Sjøstedt, Peter

    Dette brief fremlægger resultaterne af en undersøgelse af iPads betydning for studerendes læring på Institut for Sprog ved Forsvarsakademiet. Undersøgelsen rejser en række pædagogiske og tekniske spørgsmål vedrørende anvendelse af iPads i undervisningen, der kan være relevante at drøfte og...... undersøge i forbindelse med anvendelse og anskaffelse af tablets i forbindelse med undervisning. Konklusionen på den gennemførte undersøgelse på Institut for Sprog er, at det lokale studiemiljø og de studerendes individuelle præferencer for teknologi og studieteknik har stor betydning for anvendelsen af iPads...

  7. The iPad as a Tool for Play

    DEFF Research Database (Denmark)

    Johansen, Stine Liv

    Over the last couple of years, tablets - especially Apple's iPad - have become more frequent as a new, truly mobile technology in school settings, day care institutions and private homes. Tablets are being used for numerous purposes, being a sort of mix between a ‘real’ computer and a mobile phone...... and as such providing new possibilities and affordances for leaning, communication, entertainment, and play in different settings – formal as well as informal. In this paper I will present the findings from an ongoing study on the iPad as a tool for play and relate these to a discussion on the...... methodological implications and challenges related to conducting ethnographically inspired fieldwork of people’s everyday uses of mobile technologies. What is interesting about the iPad as a tool - or a toy - is the way in which it invites and supports certain types of use, and how it contributes to new...

  8. 190-C Facility <90 Day Storage Pad inspection plan

    International Nuclear Information System (INIS)

    This document provides the inspection plan for the 190-C Facility <90 Day Storage Pad. The 190-C Facility <90 Day Storage Pad stores waste oils contaminated with lead generated while draining oil from equipment within 290-C. The 190-C pumphouse originally pumped water to the C Reactor after the water was treated/filtered in an adjacent building. Characteristic waste oil is removed from the facility equipment, packaged and stored in fifty-five-gallon drums. Included in this plan are the details concerning necessary security equipment, inspection for proper sign posting and other factors that may affect the integrity of the facility. The 190-C Facility <90 Day Storage Pad shall be inspected at lease once each calendar week

  9. Pad-weighing test performed with standardized bladder volume

    DEFF Research Database (Denmark)

    Lose, G; Rosenkilde, P; Gammelgaard, J;

    1988-01-01

    with a standardized bladder volume (50% of the cystometric bladder capacity). Twenty-five female patients with stress or mixed incontinence underwent two separate tests. Test-retest results were highly correlated (r = 0.97, p less than 0.001). Nonetheless, analysis of test-retest differences revealed a variation up...... to +/- 24 g between two tests. It is concluded that this setup (i.e., standardized bladder volume) of the one-hour pad-weighing test allows for a more reliable assessment of urinary incontinence for quantitative purposes.......The result of the one-hour pad-weighing test proposed by the International Continence Society has been demonstrated to depend on the urine load during the test. To increase reproducibility of the pad-weighing test by minimizing the influence of variation in urine load the test was done...

  10. Tilting-Pad Guide Bearing in Large Hydro-unit

    Directory of Open Access Journals (Sweden)

    Li-Feng Ma

    2000-01-01

    Full Text Available A new numerical method is proposed for predicting the nonlinearity of tilting-pad guide bearing oilfilm force in the rotor-bearing system in a large hydro-unit. Nonlinear displacement and velocity of the journal center, as well as nonlinear tilting angles and angular velocities of the pads in non-stationary Reynolds equation are taken into account. This method is also suited for other small rotor-bearing system. As an example, the response due to a momentarily created unbalance is Calculated. The nonlinear motion patterns of the pad and journal whirling orbit are obtained. Finally, the nonlinear orbit is compared to the linear one that could be calculated from linear stiffness and damping coefficients. It is shown that there are important differences between those two orbits and that the nonlinear simulation is more accurate.

  11. Closing microvascular lesions with fibrin sealant-attached muscle pads.

    Science.gov (United States)

    Fehm, Nando Percy; Vatankhah, Bijan; Dittmar, Michael S; Tevetoglu, Yesim; Retzl, Gerald; Horn, Markus

    2005-01-01

    Fibrin sealants are used in a variety of surgical procedures, mainly for purposes of hemostasis and assisted wound healing. The combined use of fibrin sealant and autologous muscle pads for hemostasis was not reported previously. Arterial incisions in the common carotid artery in rats were closed by the combined application of fibrin sealant and an autologous muscle pad. Postsurgical vessel patency and degree of stenosis were evaluated by color duplex sonography, computed tomography angiography, and postmortem histology. The combined application of muscle pad and fibrin sealant and achievement of hemostasis was feasible in all animals. Seventy-eight percent of animals showed no or only slight postsurgical vessel stenosis. Our method is simple and quick to perform, showing a high potential for hemostasis in microvascular lesions. Therefore, it might be used in future experimental studies for conservation of vessel patency after arterial catheterization and in experimental or clinical vascular surgery. PMID:16184526

  12. The SciencePAD treasure hunt of Persistent Identifiers

    CERN Multimedia

    Beatrice Bressan, for the European Middleware Initiative (EMI)

    2013-01-01

    Have you ever followed a reference for an article that eventually turned out to be unavailable? Have you always thought that experiment data or research results should be permanently accessible? If so, you will probably be interested in the latest news on the current status of software and digital information issues, and you shouldn’t miss the SciencePAD Persistent Identifiers Workshop (SPID2013).   The workshop is being organised by the European Middleware Initiative (EMI) together with its SciencePAD (formerly known as ScienceSoft) project and will take place on 30 January 2013 at CERN. SciencePAD is a community-enabler, working on providing the necessary one-stop-shop tools, including software, catalogues, statistics, reference citation systems, marketplaces, technical services links, platform integration supports, etc. It allows researchers and open source software developers from scientific communities to interact with each other within and beyond their area of expertise, and co...

  13. Commercial application of the compliant pad, a space technology innovation

    International Nuclear Information System (INIS)

    This paper describes the work done to transfer technology developed, in the course of the SP100 Space Reactor Program, to commercial applications. This paper describes a cooperative program conducted by AMM and HI-Z Corporation. In the application described, the compliant pads provide the interface between Pb-Te and Bi-Te based thermoelectric modules and a heat source. It is intended that the thermoelectric modules will be used to convert high temperature waste heat into electricity or used in thermoelectric generators that are heated with fossil fuels such as propane, diesel or gasoline. The work outlined describes the effort to produce a lower temperature more affordable compliant pad, and the planned testing of the pads with the thermoelectric modules to demonstrate the technology conversion under realistic commercial conditions and determine their heat transfer effectiveness, efficiency, ease of use and reliability

  14. EXPERIMENTAL DETERMINATION OF BRAKE THERMAL EFFICIENCY AND BRAKE SPECIFIC FUEL CONSUMPTION OF DIESEL ENGINE FUELLED WITH BIO-DIESEL

    Directory of Open Access Journals (Sweden)

    M. SHIVA SHANKAR

    2010-10-01

    Full Text Available The rapid depletion in world petroleum reserves and uncertainty in petroleum supply due to political and economical reasons, as well as, the sharp escalations in the petroleum prices have stimulated the search for alternatives to petroleum fuels. The situation is very grave in developing countries like India which imports 70% of the required fuel, spending 30% of her total foreign exchange earnings on oil imports. Petroleum fuels are being consumed by agriculture and transport sector for which diesel engine happens to be the prime mover. Diesel fuelled vehicles discharge significant amount of pollutants like CO, HC, NOx, soot, lead compounds which are harmful to the universe. Though there are wide varieties of alternative fuels available, the research has not yet provided the right renewable fuel to replace diesel. Vegetable oils due to their properties being close to diesel fuel may be a promising alternative for its use in diesel engines. The high viscosity and low volatility are the major drawbacks of the use of vegetable oils in diesel engines. India is the second largest cotton producing country in the world today. The cotton seeds are available in India at cheaper price. Experiments were conducted on 5.2 BHP single cylinder four stroke water-cooled variable compression diesel engine. Methyl ester of cottonseed oil is blended with the commercially available Xtramile diesel. Cottonseed oil methyl ester (CSOME is blended in four different compositions varying from 10% to 40% in steps of 10 vol%. Using these four blends and Xtramile diesel brake thermal efficiency (BTE and brake specific fuel consumption (BSFC are determined at 17.5 compression ratio.

  15. Design and control of a dual unidirectional brake hybrid actuation system for haptic devices.

    Science.gov (United States)

    Rossa, Carlos; Lozada, José; Micaelli, Alain

    2014-01-01

    Hybrid actuators combining brakes and motors have emerged as an efficient solution to achieve high performance in haptic devices. In this paper, an actuation approach using two unidirectional brakes and a DC motor is proposed. The brakes are coupled to overrunning clutches and can apply a torque in only one rotational direction. The associated control laws, that are independent of the virtual environment model, calculate the control gains in real time in order limit the energy and the stiffness delivered by the motor to ensure stability. The reference torque is respected using the combination of the motor and the brake. Finally, an user experiment has been performed to evaluate the influence of passive and active torque differences in the perception of elasticity. The proposed actuator has a torque range of 0.03 Nm to 5.5 Nm with a 17.75 kNm (-2) torque density. PMID:25122593

  16. ANALYSIS OF POSSIBILITY TO AVOID A RUNNING-DOW ACCIDENT TIMELY BRAKING

    Directory of Open Access Journals (Sweden)

    Sarayev, A.

    2013-06-01

    Full Text Available Such circumstances under which the drive can stop the vehicle by applying timely braking before reaching the pedestrian crossing or decrease the speed to the safe limit to avoid a running-down accident is considered.

  17. Morgan Brake National Wildlife Refuge Deer Harvest Records from 2011 Season

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — These harvest data are from Morgan Brake during the 2011 deer season. They measure weight, antler size, prevalence of milk, and number of deer harvested.

  18. Mathews Brake National Wildlife Refuge public use review and development plan

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This document addresses the ten Public Use Requirements for Mathews Brake National Wildlife Refuge as well as General Impressions of the review team.

  19. STUDY ON THE CONTROL SYSTEM OF HYDRAULIC MOMENT-ADJUSTED BRAKE FOR DOWNWARD BELT CONVEYOR

    Institute of Scientific and Technical Information of China (English)

    孟国营; 徐志强; 霍森; 方佳雨

    1997-01-01

    Having analyzed the drawbacks on the design of control system of hydraulic momentadjusted brake system, the author presents a closed loop control system in the process of start and braking of the conveyer. On the basis of the concept of the critical time and the critical acceleration and its deductions, the working mode of the conveyer can be identified and controlled in feedback, furthermore, thus realize the process of soft start. In the deceleration process, the author points out the problems that exist in the present control system and sets forward the control process that acted by the combined function of brake moment of motor and the drag torque of hydraulic brake at the beginning of deceleration, it will further improved reliability of conveyor system.

  20. Mathews Brake National Wildlife Refuge Deer Harvest Records from 2011 Season

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — These harvest data are from Mathews Brake during the 2011 deer season. They measure weight, antler size, prevalence of milk, and number of deer harvested.

  1. Upper Ouachita and Handy Brake National Wildlife Refuge: Comprehensive Conservation Plan

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This Comprehensive Conservation Plan CCP was written to guide management on Upper Ouachita and Handy Brake NWRs for the next 15 years. This plan outlines the...

  2. Dynamic Analysis of a Floating Vertical Axis Wind Turbine Under Emergency Shutdown Using Hydrodynamic Brake

    DEFF Research Database (Denmark)

    Wang, K.; Hansen, Martin Otto Laver; Moan, T.

    2014-01-01

    Emergency shutdown is always a challenge for an operating vertical axis wind turbine. A 5-MW vertical axis wind turbine with a Darrieus rotor mounted on a semi-submersible support structure was examined in this study. Coupled non-linear aero-hydro-servo-elastic simulations of the floating vertical...... axis wind turbine were carried out for emergency shutdown cases over a range of environmental conditions based on correlated wind and wave data. When generator failure happens, a brake should be applied to stop the acceleration of the rotor to prevent the rotor from overspeeding and subsequent disaster....... In addition to the traditional mechanical brake, a novel hydrodynamic brake was presented to apply to the shutdown case. The effects of the hydrodynamic brake on the platform motions and structural loads under normal operating conditions and during the emergency shutdown events were evaluated. The...

  3. Mobile Acoustical Bat Monitoring Annual Summary Report CY 2012 to 2015 - Morgan Brake National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — These reports summarize bat calls collected along transects at Morgan Brake National Wildlife Refuge between 2012 and 2015. Calls were classified using Bat Call ID...

  4. Mobile Acoustical Bat Monitoring Annual Summary Report CY 2012 to 2015 - Mathews Brake National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — These reports summarize bat calls collected along transects at Mathews Brake National Wildlife Refuge between 2012 and 2015. Calls were classified using Bat Call ID...

  5. Development of an Engine Air-Brake for Quiet Drag Applications Project

    Data.gov (United States)

    National Aeronautics and Space Administration — A novel quiet engine air-brake (EAB) is proposed in response to NASA's solicitation for active and passive noise control concepts for conventional and advanced...

  6. An analysis of the friction mechanism on brake gear of railway rolling stock

    Directory of Open Access Journals (Sweden)

    J. H. Barnard

    1985-03-01

    Full Text Available Friction energy dissipation at an interface involves a wide range of interdisciplinary concepts. As the demand for higher operating speeds increased, the limitations of cast iron as the traditional friction material for rail transport brakes became more apparent. Only through an intensive analysis of the interfacial interaction between the brake block and brake path could the problems encountered with other promising friction materials be solved. The article deals with the difficulties pertaining to the early composite materials, and indicates how these were overcome by the understanding and implementation of new techniques not previously associated with conventional systems connected with railway braking. Two composite materials, that is 840/N for locomotives and freight wagons where mass oriented momentum dominates, and high friction composite 655/C for passenger vehicles with a predominantly speed-oriented momentum, are presently used.

  7. Environmental Assessment of the Proposed Opening of Mathews Brake National Wildlife Refuge to Fishing

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This proposal calls for the opening of Mathews Brake NWR to sport fishing. General regulations pertaining to licenses, creel limits, and methods of taking fish will...

  8. Theoretical and experimental study of an energy-reinforced braking radiation photon beam

    International Nuclear Information System (INIS)

    This research thesis reports the theoretical study of a photon beam raised towards high energies, its experimental implementation, the definition of a gamma spectrometry method which aimed at checking various hypotheses used in the beam theoretical study. After a presentation of the theory of phenomena of electron braking radiation, of materialisation of photons into positon-negaton pair, and of issues related to multiple Coulomb diffusion, the author reports the study of the different solutions which allow a photon beam to be obtained. A braking radiation of mono-kinetic electron has been used. This braking radiation is reinforced by absorption of low energy protons in a column of lithium hydride. The author describes how the beam is built up, and the experimental approach. He describes how raw data are processed to get rid of the influence of the multiple Coulomb diffusion and of the braking radiation. Experimental results are compared with those obtained by convolution of photon spectra and differential cross section

  9. Development of an Engine Air-Brake for Quiet Drag Applications Project

    Data.gov (United States)

    National Aeronautics and Space Administration — A novel quiet engine air-brake is proposed in response to NASA's solicitation for concepts for active and passive control of noise sources for conventional and...

  10. An approach to evaluate capacitance, capacitive reactance and resistance of pivoted pads of a thrust bearing

    Science.gov (United States)

    Prashad, Har

    1992-07-01

    A theoretical approach is developed for determining the capacitance and active resistance between the interacting surfaces of pivoted pads and thrust collar, under different conditions of operation. It is shown that resistance and capacitive reactance of a thrust bearing decrease with the number of pads times the values of these parameters for an individual pad, and that capacitance increases with the number of pads times the capacitance of an individual pad. The analysis presented has a potential to diagnose the behavior of pivoted pad thrust bearings with the angle of tilt and the ratio of film thickness at the leading to trailing edge, by determining the variation of capacitance, resistance, and capacitive reactance.

  11. Compression Pad Cavity Heating Augmentation on Orion Heat Shield

    Science.gov (United States)

    Hollis, Brian R.

    2011-01-01

    An experimental study has been conducted to assess the effects of compression pad cavities on the aeroheating environment of the Project Orion Crew Exploration Vehicle heat shield. Testing was conducted in Mach 6 and 10 perfect-gas wind tunnels to obtain heating measurements in and around the compression pads cavities using global phosphor thermography. Data were obtained over a wide range of Reynolds numbers that produced laminar, transitional, and turbulent flow within and downstream of the cavities. The effects of cavity dimensions on boundary-layer transition and heating augmentation levels were studied. Correlations were developed for transition onset and for the average cavity-heating augmentation.

  12. The pixel readout system for the PHENIX pad chambers

    International Nuclear Information System (INIS)

    A new concept for two-dimensional position readout of wire chambers is described. The basic idea is to use a cathode segmented into small pixels that are read out in specific groups (pads). The electronics is mounted on the outer face of the chamber with a chip-on-board technique, pushing the material thickness to a minimum. The system described here, containing 210 000 readout channels, will be used to read out the pad chambers in the PHENIX experiment at the Relativistic Heavy Ion Collider (RHIC)

  13. SCIENTIFIC PROGRESS OF THE MC-PAD NETWORK

    CERN Document Server

    Aguilar, J; Ambalathankandy, P; Apostolakis, J; Arora, R; Balog, T; Behnke, T; Beltrame, P; Bencivenni, G; Caiazza, S; Dong, J; Heller, M; Heuser, J; Idzik, M; Joram, C; Klanner, R; Koffeman, E; Korpar, S; Kramberger, G; Lohmann, W; Milovanović, M; Miscetti, S; Moll, M; Novgorodova, O; Pacifico, N; Pirvutoiu, C; Radu, R; Rahman, S; Rohe, T; Ropelewski, L; Roukoutakis, F; Schmidt, C; Schön, R; Sibille, J; Tsagri, M; Turala, M; Van Beuzekom, M; Verheyden, R; Villa, M; Zappon, F; Zawiejski, L; Zhang, J

    2013-01-01

    MC-PAD is a multi-site Initial Training Network on particle detectors in physics experiments. It comprises nine academic participants, three industrial partners and two associated academic partners. 17 recruited Early Stage and 5 Experienced Researchers have performed their scientific work in the network. The research and development work of MC-PAD is organized in 12 work packages, which focus on a large variety of aspects of particle detector development, electronics as well as simulation and modelling. The network was established in November 2008 and lasted until October 2012 (48 months). This report describes the R&D activities and highlights the main results achieved during this period.

  14. Best iPad Apps The Guide for Discriminating Downloaders

    CERN Document Server

    Meyers, Peter

    2010-01-01

    What really wows iPad fans is when their touchscreen does what's impossible on other gadgets: the finger-painting app that turns a cross-country flight into a moving art class, the mini music studio (two-dozen instruments strong, each with motion-induced warble effects), and the portable fireworks display that you sculpt by swiping. Problem is, with tens of thousands of apps available for your iPad, who knows what to download? You can try to sort through a gazillion customer reviews with a mix of 5- and 1-star ratings, but that's a head-hurting time-waster. The stakes are getting higher, too

  15. The pixel readout system for the PHENIX pad chambers

    Energy Technology Data Exchange (ETDEWEB)

    Nilsson, Paul B., E-mail: paul.nilsson@kosufy.lu.se; Barrette, J.; Bryan, W.; Fraenkel, Z.; Greene, V.; Garpman, S.; Gustafsson, H.-A.; Jagadish, U.; Nikkinen, L.; Lacey, R.; Lauret, J.; Mark, S.K.; Milov, A.; O' Brien, E.; Oskarsson, A.; Oesterman, L.; Otterlund, I.; Pinkenburg, C.; Ravinovich, I.; Rose, A.; Silvermyr, D.; Sivertz, M.; Smith, M.; Stenlund, E.; Svensson, T.; Teodorescu, O.; Tserruya, I.; Xie, W.; Young, G.R

    1999-12-27

    A new concept for two-dimensional position readout of wire chambers is described. The basic idea is to use a cathode segmented into small pixels that are read out in specific groups (pads). The electronics is mounted on the outer face of the chamber with a chip-on-board technique, pushing the material thickness to a minimum. The system described here, containing 210 000 readout channels, will be used to read out the pad chambers in the PHENIX experiment at the Relativistic Heavy Ion Collider (RHIC)

  16. Validity of Spontaneous Braking and Lane Changing with Scope of Awareness by Using Measured Traffic Flow

    OpenAIRE

    Kohei Arai; Steven Ray Sentinuwo

    2013-01-01

    This paper presents the validation method and its evaluation of the spontaneous braking and lane changing with scope awareness parameter. By using the real traffic flow data, the traffic cellular automaton model that accommodate these two driver behaviors, e.g., spontaneous braking and driver scope awareness has been compared and evaluated. The real traffic flow data have been observed via video-recording captured from real traffic situation. The validation results shown that by accommodate s...

  17. Rail temperature rise characteristics caused by linear eddy current brake of high-speed train

    OpenAIRE

    Xiaoshan Lu; Yunfeng Li; Mengling Wu; Jianyong Zuo; Wei Hu

    2014-01-01

    The rail temperature rises when the linear eddy current brake of high-speed train is working, which may lead to a change of rail physical characteristics or an effect on train operations. Therefore, a study concerning the characteristics of rail temperature rise caused by eddy current has its practical necessity. In the research, the working principle of a linear eddy current brake is introduced and its FEA model is established. According to the generation mechanism of eddy current, the theor...

  18. An approach of inertia compensation based on electromagnetic induction in brake test

    OpenAIRE

    Xiaowen Li; Han Que

    2016-01-01

    This paper briefly introduced the operational principle of the brake test bench, and points out the shortcomings when controlling the current of brake test, which means the reference measuring data is instantaneous. Aimed at this deficiency, a current control model based on electromagnetic induction and DC voltage is proposed. On the principle of electromagnetic induction, continuous data and automatic processes are realized. It significantly minimized errors owing to instantaneous data, and ...

  19. Advanced Emergency Braking Controller Design for Pedestrian Protection Oriented Automotive Collision Avoidance System

    OpenAIRE

    Guo Lie; Ren Zejian; Ge Pingshu; Chang Jing

    2014-01-01

    Automotive collision avoidance system, which aims to enhance the active safety of the vehicle, has become a hot research topic in recent years. However, most of the current systems ignore the active protection of pedestrian and other vulnerable groups in the transportation system. An advanced emergency braking control system is studied by taking into account the pedestrians and the vehicles. Three typical braking scenarios are defined and the safety situations are assessed by comparing the cu...

  20. Magnetic Braking and Viscous Damping of Differential Rotation in Cylindrical Stars

    OpenAIRE

    Cook, James N.; Shapiro, Stuart L.; Stephens, Branson C.

    2003-01-01

    Differential rotation in stars generates toroidal magnetic fields whenever an initial seed poloidal field is present. The resulting magnetic stresses, along with viscosity, drive the star toward uniform rotation. This magnetic braking has important dynamical consequences in many astrophysical contexts. For example, merging binary neutron stars can form "hypermassive" remnants supported against collapse by differential rotation. The removal of this support by magnetic braking induces radial fl...

  1. Analysis of electrodynamic brake for utilization in systems with rotating shafts

    OpenAIRE

    Sokolov, Georgii

    2016-01-01

    The goal of this study was to conduct an analysis of an opportunity to apply eddy current brakes in dynamical systems containing rotating shafts. While conducting the research the general principles of deceleration, eddy currents’ origin, basics of magnetism and currently existing types of brakes were clarified and gathered briefly, but informatively. The theory which is explained in this thesis was taken from reliable secondary sources. The concepts of physics were investigated from sever...

  2. On a Flywheel-Based Regenerative Braking System for Regenerative Energy Recovery

    OpenAIRE

    Hsu, Tai-Ran

    2013-01-01

    This paper presents a unique flywheel-based regenerative energy recovery, storage and release system developed at the author's laboratory. It can recover and store regenerative energy produced by braking a motion generator with intermittent rotary velocity such as the rotor of a wind turbogenerator subject to intermittent intake wind and the axels of electric and hybrid gas-electric vehicles during frequent coasting and braking. Releasing of the stored regenerative energy in the flywheel is c...

  3. Physico-chemical characterization and oxidative reactivity evaluation of aged brake wear particles

    OpenAIRE

    Zhao Jiayuan; Lewinski Nastassja; Riediker Michael

    2015-01-01

    Brake wear dust is a significant component of traffic emissions and has been linked to adverse health effects. Previous research found a strong oxidative stress response in cells exposed to freshly generated brake wear dust. We characterized aged dust collected from passenger vehicles, using microscopy and elemental analyses. Reactive oxygen species (ROS) generation was measured with acellular and cellular assays using 2′7-dichlorodihydrofluorescein dye. Microscopy analyses revealed sam...

  4. Wear, friction, and temperature characteristics of an aircraft tire undergoing braking and cornering

    Science.gov (United States)

    Mccarty, J. L.; Yager, T. J.; Riccitiello, S. R.

    1979-01-01

    An investigation to evaluate the wear, friction, and temperature characteristics of aircraft tire treads fabricated from different elastomers is presented. The braking and cornering tests performed on aircraft tires retreaded with currently employed and experimental elastomers are described. The tread wear rate is discussed in relation to the slip ratio during braking and yaw angle during cornering. The extent of wear in either operational mode is examined in relation to the runway surface.

  5. Casting of Brake Disc and Impeller from Aluminium Scrap Using Silica Sand

    OpenAIRE

    Oladeji A. OGUNWOLE; Oluwafemi A. OLUGBOJI; Matthew S. ABOLARIN

    2007-01-01

    The impeller blade and the brake disc were produced using sand casting method. Wooden patterns of the two castings were constructed incorporating the necessary allowances. Green and moulding technique utilizing locally available materials were used for preparing the moulds. Aluminium scraps were used as the casting material. Melting of the Aluminium scraps was obtained using a crucible furnace and finally pouring the molten metal into the sand mould to obtain the impeller and the brake disc.A...

  6. Driver head displacement during (automatic) vehicle braking tests with varying levels of distraction

    OpenAIRE

    Rooij, L. van; Pauwelussen, J.; Camp, O.M.G.C. op den; Janssen, J. M.

    2013-01-01

    Vehicle occupant behavior in emergency driving conditions has a large effect on traffic safety. Distraction is estimated to be the cause of 15-20% of all crashes. Additionally, the posture of the occupants prior to the possibly unavoidable crash is known to have a large effect on the injury reducing performance of the restraint system. In this study it is investigated whether braking settings as well as driver distraction influence the kinematic response of an occupant during braking events, ...

  7. Swing characteristic of pads in tilting pad bearing%可倾瓦轴承瓦块摆动特性

    Institute of Scientific and Technical Information of China (English)

    王永亮; 刘占生; 钱大帅

    2011-01-01

    The geometric relations of pad on tilting-pad bearing were studied,the relationship between tile pendulum angle and structural parameters were established by the oil-film force model of finite length tilting pad bearing and equilibrium equation,and the basic law of tile pendulum angle change was analyzed.The study shows that the tile pendulum angle is determined by the pad structural parameters,the eccentricity ratio of tilting pad bearing and the clearance ratio,but independent of shaft rotating speed,viscosity of lubrication oil,etc.A case study of a tilting pad bearing with 80 deg pad arc angle,0.5 offset was performed to illustrate the law of tile pendulum angle varies with eccentricity ratio and clearance ratio.It is revealed that,when the structural parameters of tilting pad bearing are constant,the tile pendulum angle increases first and then decreases with the original eccentricity ratio increases,and increases linearly with the increasing of bearing clearance ratio.%研究可倾瓦轴承瓦块摆动几何关系,基于分离变量法建立了有限长轴承油膜压力模型及瓦块力矩平衡方程,获得瓦块摆角与轴承参数之间的函数关系;以瓦块包角为80°、支点偏移量为0.5的四瓦块可倾瓦轴承为研究对象,计算分析其瓦块的摆动特性.理论推导表明,瓦块静平衡摆角只与瓦块结构参数、轴颈相对瓦块偏心率、间隙比有关,而与轴颈转速、油膜粘度等无关;数值仿真结果表明,当瓦块结构参数一定时,瓦块静平衡摆角随原始偏心率增大呈先增大后减小趋势,随轴承间隙比增大呈线性增加趋势.研究结果为建立工程实用的可倾瓦轴承非线性油膜力模型提供理论依据.

  8. Silicon nanoparticle-functionalized fiberglass pads for sampling

    International Nuclear Information System (INIS)

    We used wet treatment to immobilize luminescent silicon nanoparticles on industrial glass fibers to impart optical and chemical functions to the fiber. Carpets or pads consisting of thousands of fibers are processed in parallel, enhancing the sensitivity of detection and the sampled volume. Treated pads exhibit strong luminescence, characteristic of the luminescence of the particles; showing no shift, broadening, or reduction of quantum efficiency. We demonstrate that drawing material by the pad due to physical adsorption can be reversed. We also demonstrate that allylamine can be covalently attached by photoinduced irradiation reactions, which results in imprinting the amine emission spectrum, providing spectral recognition. The imprint accompanied with a blue-shifting of the luminescence spectrum of the probe, allowing examination of the effect of termination on the nanoparticle structure. The shift is found to be consistent with an increase in the bandgap of the Si nanoparticle and is consistent with Quantum Monte Carlo calculations. In addition to sampling, the nano probe pad has the potential to enable a variety of biomedical applications through subsequent attachment.

  9. Fibroma of tendon sheath of the infrapatellar fat pad

    International Nuclear Information System (INIS)

    We report on a 13-year-old boy who was found to have a fibroma of the tendon sheath associated with the patellar tendon and within Hoffa's fat pad of the knee. This benign tumor has never been described in this location previously. The MRI characteristics are correlated with the histologic findings. (orig.)

  10. Fabrication and testing of a large area cathode pad chamber

    International Nuclear Information System (INIS)

    Saha Institute of Nuclear Physics (SINP) is participating in the Forward Muon Spectrometer collaboration of ALICE at CERN and is responsible in the design and fabrication of the second tracking station. The tracking detectors will be cathode pad chambers (CPC). Two small CPC prototypes have already been fabricated and tested at CERN

  11. Evaluation of the microdialysis technique in the dog fat pad

    DEFF Research Database (Denmark)

    Stallknecht, B; Madsen, J; Galbo, H; Bülow, J

    In the present study the microdialysis technique was evaluated in an isolated autoperfused dog fat pad. Concentrations of glucose, lactate, and glycerol were measured in interstitial fluid by microdialysis and simultaneously in arterial and adipose venous plasma. Adipose tissue blood flow was...

  12. Quantum mutual information and the one-time pad

    International Nuclear Information System (INIS)

    Alice and Bob share a correlated composite quantum system AB. If AB is used as the key for a one-time pad cryptographic system, we show that the maximum amount of information that Alice can send securely to Bob is the quantum mutual information of AB

  13. Safety assessment of the Area 6 Decontamination Pad and Laundry

    International Nuclear Information System (INIS)

    The Safety Assessment of the Area 6 Decontamination Pad and Laundry, prepared in accordance with DOE Order 5481.1A, identifies and evaluates potential radiation and chemical hazards to personnel, and impacts on the environment. Site and facility characteristics, as well as routine and nonroutine operations are discussed. Hypothetical incidents and accidents are described and evaluated. 3 figures, 1 table

  14. The floating cardiac fat pad-sign of occult pneumothorax.

    Science.gov (United States)

    Kaufman, Claire; Bokhari, S A Jamal

    2016-08-01

    Pneumothoraces are a possible sequela of chest trauma with potential morbidity and mortality if not recognized and treated promptly. A portable supine chest radiograph is frequently the first radiologic study performed in the setting of trauma. While large pneumothoraces can be readily recognized on these radiographs, smaller pneumothoraces are missed in up to 15 % of trauma patients. There are many radiographic signs of occult pneumothoraces, and we are presenting a new radiographic sign of occult pneumothorax. The floating cardiac fat pad sign occurs when pleural air collects anteriorly and superiorly in the most non-dependent portion of the chest lifting the pericardial fat pad off the diaphragm. Lung markings are still seen surrounding the pericardial fat pad due to the inflated lower lobe of the lung resting dependently. Rapid and accurate identification of pneumothoraces is critical but often difficult on chest radiographs. Although there are many existing radiographic signs for identification of pneumothorax, prospective identification of small pneumothoraces is still relatively poor. Here, we describe an additional sign which aides in the detection of pneumothoraces, the floating cardiac fat pad. When present, this should prompt further evaluation with chest CT or upright chest radiograph. PMID:27250975

  15. Discontinuity effects in dynamically loaded tilting pad journal bearings

    DEFF Research Database (Denmark)

    Thomsen, Kim; Klit, Peder; Vølund, Anders

    2011-01-01

    This paper describes two discontinuity effects that can occur when modelling radial tilting pad bearings subjected to high dynamic loads. The first effect to be treated is a pressure build-up discontinuity effect. The second effect is a contact-related discontinuity that disappears when a contact...

  16. Using the iPad in a Sport Education Season

    Science.gov (United States)

    Sinelnikov, Oleg A.

    2012-01-01

    The latest advances in technology are inevitably making their way into schools and gymnasiums across the country. This article provides a descriptive account of how one physical education teacher incorporated the use of an iPad in a middle-school volleyball sport education season. The salient structural elements of sport education, such as…

  17. Prevent P.A.D.: Know Your Numbers

    Science.gov (United States)

    ... the progression of P.A.D.," she adds. African Americans at Risk African Americans have a particularly high prevalence of risk factors ... have high blood pressure, hypertension, and diabetes. Further, African Americans, especially women, tend toward obesity and inactivity. The ...

  18. Control and sensor techniques for PAD servo motor drive

    DEFF Research Database (Denmark)

    Zsurzsan, Tiberiu-Gabriel; Zhang, Zhe; Andersen, Michael A. E.;

    2015-01-01

    torque is 4 Nm, without any additional gearing. The whole motor is fully non-magnetic, enabling its use in applications where magnetic neutrality is of importance. The main challenges of the PAD are the hysteretic behavior of the ceramic actuators used and their highly capacitive nature. After...

  19. Ereaders, the iPad--Is That All There Is?

    Science.gov (United States)

    Lankes, R. David

    2010-01-01

    The device industry is blowing a great opportunity to revolutionize reading. At the Consumer Electronics Show in January, a dozen or more ebook readers and tablets were trotted out as the wave of the future. Since then, Apple has revealed the iPad, Sony has started shipping a touchscreen version of its eBook, and Spring Design has started shipping…

  20. The effect and clinical application of homemade tracheotomy incision nursing pads.

    Science.gov (United States)

    Yao, Yachun; Xu, Li; Du, Kun; Zhang, Jiajun

    2014-09-01

    To investigate the effect and clinical application of the homemade tracheotomy incision nursing pads. 83 patients suffering tracheotomy were randomly divided into experimental and control groups. The experimental group was treated with the homemade tracheotomy incision nursing pads, and the control group was treated with the traditional tracheotomy nursing pads. Subsequently, the number of nursing pads used in 2 weeks, tracheotomy incision bacterial colonies and the comfort of patient between the two groups of pads was compared. The number of nursing pads used by the experimental group was smaller than the control group, and the tracheotomy incision bacterial colonies in the experimental group were fewer than the control group (P 0.05). Thus, the results show that the effect of homemade tracheotomy incision nursing pads is greater compared to the traditional nursing pads. PMID:24633484

  1. Facts about Peripheral Arterial Disease (P.A.D.) for African Americans

    Science.gov (United States)

    ... About Peripheral Arterial Disease (P.A.D.) for African Americans One in every 20 Americans over the age ... stroke. P.A.D. is more common in African Americans than any other racial or ethnic group. This ...

  2. Metacarpophalangeal joint synovial pad fibrotic proliferation in 63 horses

    International Nuclear Information System (INIS)

    Medical records, radiographs, and sonograms of 63 horses with metacarpophalangeal joint synovial pad proliferation were examined retrospectively. AR horses had lameness, joint effusion, or both signs associated with one or both metacarpophalangeal joints. Bony remodeling and concavity of the distodorsal aspect of the third metacarpal bone (Mc3) just proximal to the metacarpal condyles was identified by radiography in 71 joints (93%); 24 joints (32%) had radiographic evidence of a chip fracture located at the proximal dorsal aspect of the proximal phalanx. Fifty-four joints (71%) were examined by ultrasound. The mean +- SD sagittal thickness of the synovial pad was 11.3 +- 2.8 mm. Seventy-nine percent of the horses had single joint involvement with equal distribution between the right and left forelimbs. Sixty-eight joints in 55 horses were treated by arthroscopic surgery. Sixty joints (88%) had debridement of chondral or osteochondral fragmentation from the dorsal surface of Mc3 beneath the synovial pad and 30 joints (44%) had a bone chip fracture removed from the medial or lateral proximal dorsal eminence of the proximal phalanx. Complete or partial excision of both medial and lateral synovial pads was completed in 42 joints. Only the medial synovial pad was excised or trimmed in 21 joints, and 5 joints had only the lateral pad removed. Eight joints in eight horses were treated by stall rest, administration of intra-articular medication and systemic nonsteroidal anti-inflammatory drugs. Follow-up information was obtained for 50 horses treated surgically and for eight horses treated medically. Forty-three (86%) that had surgery returned to racing; 34 (68%) raced at an equivalent or better level than before surgery. Three (38%) of the medically treated horses returned to racing; only one horse raced better than the preinjury level. Horses that returned to racing at a similar or equal level of performance were significantly younger in age than horses returning at a

  3. A global strategy based on experiments and simulations for squeal prediction on industrial railway brakes

    Science.gov (United States)

    Sinou, J.-J.; Loyer, A.; Chiello, O.; Mogenier, G.; Lorang, X.; Cocheteux, F.; Bellaj, S.

    2013-09-01

    This paper presents an overview of recent experimental and numerical investigations on industrial railway brakes. The goal of the present study is to discuss the relevance of the mechanical modeling strategy for squeal prediction. Specific experimental set-ups based on transient and controlled braking tests are designed for this purpose. Measurements are performed on it to investigate the dynamic behavior of TGV squeal noise and its squeal characterization through experiments. It will be demonstrated that it is possible to build consistent and efficient finite element models to simulate squeal events in TGV brake systems. The numerical strategy will be presented, including not only the modeling of the TGV brake system and the stability analysis, but also the transient nonlinear dynamic and computational process based on efficient reduced basis. This complete numerical strategy allows us to perform relevance squeal prediction on industrial railway brakes. This study comes within the scope of a research program AcouFren that is supported by ADEME (Agence De l'Environnement et de la Maîtrise de l'Energie) concerning the reduction of the squeal noise generated by high power railway disc brakes. experiments with an evolution of the rotational speed of the disc: these tests are called "transient braking tests" and correspond to real braking tests, experiments with a controlled steady rotational speed (i.e. dynamic fluctuations in rotational speed are not significant): these tests are called "controlled braking tests". In the present study, the Continuous Wavelet Transform (CWT) [20] is used to study the time-history responses of the TGV brake system. So, a brief basic theory of the wavelet analysis that transforms a signal into wavelets that are well localized both in frequency and time is presented in this part of the paper. Considering a function f(t), the associated Continuous Wavelet Transform (CWT) corresponds to a wavelet transform given by W(a,b

  4. Functionally different pads on the same foot allow control of attachment: stick insects have load-sensitive "heel" pads for friction and shear-sensitive "toe" pads for adhesion.

    Directory of Open Access Journals (Sweden)

    David Labonte

    Full Text Available Stick insects (Carausius morosus have two distinct types of attachment pad per leg, tarsal "heel" pads (euplantulae and a pre-tarsal "toe" pad (arolium. Here we show that these two pad types are specialised for fundamentally different functions. When standing upright, stick insects rested on their proximal euplantulae, while arolia were the only pads in surface contact when hanging upside down. Single-pad force measurements showed that the adhesion of euplantulae was extremely small, but friction forces strongly increased with normal load and coefficients of friction were [Formula: see text] 1. The pre-tarsal arolium, in contrast, generated adhesion that strongly increased with pulling forces, allowing adhesion to be activated and deactivated by shear forces, which can be produced actively, or passively as a result of the insects' sprawled posture. The shear-sensitivity of the arolium was present even when corrected for contact area, and was independent of normal preloads covering nearly an order of magnitude. Attachment of both heel and toe pads is thus activated partly by the forces that arise passively in the situations in which they are used by the insects, ensuring safe attachment. Our results suggest that stick insect euplantulae are specialised "friction pads" that produce traction when pressed against the substrate, while arolia are "true" adhesive pads that stick to the substrate when activated by pulling forces.

  5. The Influence of Swirl Brakes on the Rotordynamic Forces Generated by Discharge-to-Suction Leakage Flows in Centrifugal Pumps

    OpenAIRE

    Sivo, Joseph M.; Allan J. Acosta; Brennen, Christopher E.; Caughey, Thomas K.

    1995-01-01

    Increasing interest has been given to swirl brakes as a means of reducing destabilizing rotordynamic forces due to leakage flows in new high speed rocket turbopumps. Although swirl brakes have been used successfully in practice (such as with the Space Shuttle HPOTP), no experimental tests until now have been performed to demonstrate their beneficial effect over a range of leakage flow rates. The present study investigates the effect of swirl brakes on rotordynamic forces generated by discha...

  6. Effect of coordination of optimal reclosing and fuzzy controlled braking resistor on transient stability during unsuccessful reclosing

    OpenAIRE

    Ali, Mohd.Hasan; Murata, Toshiaki; Tamura, Junji

    2006-01-01

    This paper analyzes the effect of the coordination of optimal reclosing and fuzzy logic-controlled braking resistor on the transient stability of a multimachine power system in case of an unsuccessful reclosing of circuit breakers. The transient stability performance of the coordinated operation of optimal reclosing and fuzzy controlled braking resistor is compared to that of the coordinated operation of conventional auto-reclosing and fuzzy controlled braking resistor. The effectiveness of t...

  7. Arachnids secrete a fluid over their adhesive pads.

    Directory of Open Access Journals (Sweden)

    Anne M Peattie

    Full Text Available BACKGROUND: Many arachnids possess adhesive pads on their feet that help them climb smooth surfaces and capture prey. Spider and gecko adhesives have converged on a branched, hairy structure, which theoretically allows them to adhere solely by dry (solid-solid intermolecular interactions. Indeed, the consensus in the literature is that spiders and their smooth-padded relatives, the solifugids, adhere without the aid of a secretion. METHODOLOGY AND PRINCIPAL FINDINGS: We investigated the adhesive contact zone of living spiders, solifugids and mites using interference reflection microscopy, which allows the detection of thin liquid films. Like insects, all the arachnids we studied left behind hydrophobic fluid footprints on glass (mean refractive index: 1.48-1.50; contact angle: 3.7-11.2°. Fluid was not always secreted continuously, suggesting that pads can function in both wet and dry modes. We measured the attachment forces of single adhesive setae from tarantulas (Grammostola rosea by attaching them to a bending beam with a known spring constant and filming the resulting deflection. Individual spider setae showed a lower static friction at rest (26%±2.8 SE of the peak friction than single gecko setae (Thecadactylus rapicauda; 96%±1.7 SE. This may be explained by the fact that spider setae continued to release fluid after isolation from the animal, lubricating the contact zone. SIGNIFICANCE: This finding implies that tarsal secretions occur within all major groups of terrestrial arthropods with adhesive pads. The presence of liquid in an adhesive contact zone has important consequences for attachment performance, improving adhesion to rough surfaces and introducing rate-dependent effects. Our results leave geckos and anoles as the only known representatives of truly dry adhesive pads in nature. Engineers seeking biological inspiration for synthetic adhesives should consider whether model species with fluid secretions are appropriate to their

  8. Test results with a novel high-resolution wire chamber with interpolative pad readout

    International Nuclear Information System (INIS)

    A novel type of wire chamber has been constructed and first results have been obtained. The chamber has a specially constructed cathode plane, consisting of 1.5x2 mm2 pads in parallel rows. The pads in a row are connected resistively and every nth pad is read out. A position resolution of about 100 μm has been measured along the pad rows using charge division, with 6 mm between the readout points. (orig.)

  9. Performance analysis of a two stage pad cooling system in broiler houses

    OpenAIRE

    Petek, Metin; DİKMEN, Serdal; OĞAN, Mehmet Mustafa

    2012-01-01

    The cooling performance of a traditional (control) and two stage evaporative pad cooling system (experiment), including pad and fan with tunnel ventilation, for poultry houses and the growth performance of broilers reared in these systems was compared in a study performed during extreme summer temperatures. The experimental unit had a two stage pad cooling system, which consisted of underground tubes and a box, followed by a pad cooling system with tunnel ventilation. The control unit had a t...

  10. Big brake singularity is accommodated as an exotic quintessence field

    CERN Document Server

    Chimento, Luis P

    2015-01-01

    We describe a big brake singularity in terms of a modified Chaplygin gas equation of state $p=(\\ga_{m}-1)\\rho+\\al\\ga_{m}\\rho^{-n}$, accommodate this late-time event as an exotic quintessence model obtained from an energy-momentum tensor, and focus on the cosmological behaviour of the exotic field, its kinetic energy and the potential energy. At background level, the exotic field does not blow-up whereas its kinetic energy and potential both grow without limit near the future singularity. We evaluate the classical stability of this background solution by examining the scalar perturbations of the metric along with the inclusion of entropy perturbation in the perturbed pressure. Within the Newtonian gauge, the gravitational field approaches to a constant near the singularity plus additional regular terms. When the perturbed exotic field is associated with $\\al>0$, the perturbed pressure and contrast density both diverge whereas the perturbed exotic field and the divergence of exotic field's velocity go to zero e...

  11. Braking index of isolated uniformly rotating magnetized pulsars

    CERN Document Server

    Hamil, Oliver; Urbanec, Martin; Urbancova, Gabriela

    2015-01-01

    Isolated pulsars are rotating neutron stars with accurately measured angular velocities $\\Omega$, and their time derivatives which show unambiguously that the pulsars are slowing down. Although the exact mechanism of the spin-down is a question of debate in detail, the commonly accepted view is that it arises through emission of magnetic dipole radiation (MDR) from a rotating magnetized body. Other processes, including the emission of gravitational radiation, and of relativistic particles (pulsar wind), are also being considered. The calculated energy loss by a rotating pulsar with a constant moment of inertia is assumed proportional to a model dependent power of $\\Omega$. This relation leads to the power law $\\dot{\\Omega}$ = -K $\\Omega^{\\rm n}$ where $n$ is called the braking index. The MDR model predicts $n$ exactly equal to 3. Selected observations of isolated pulsars provide rather precise values of $n$, individually accurate to a few percent or better, in the range 1$ <$ n $ < $ 2.8, which is consi...

  12. Radiative braking in the extended exosphere of GJ436b

    CERN Document Server

    Bourrier, Vincent; Etangs, Alain Lecavelier des

    2015-01-01

    The recent detection of a giant exosphere surrounding the warm Neptune GJ436 b has shed new light on the evaporation of close-in planets, revealing that moderately irradiated, low-mass exoplanets could make exceptional targets for studying this mechanism and its impact on the exoplanet population. Three HST/STIS observations were performed in the Lyman-$\\alpha$ line of GJ436 at different epochs, showing repeatable transits with large depths and extended durations. Here, we study the role played by stellar radiation pressure on the structure of the exosphere and its transmission spectrum. We found that the neutral hydrogen atoms in the exosphere of GJ436 b are not swept away by radiation pressure as shown to be the case for evaporating hot Jupiters. Instead, the low radiation pressure from the M-dwarf host star only brakes the gravitational fall of the escaping hydrogen toward the star and allows its dispersion within a large volume around the planet, yielding radial velocities up to about -120 km s$^{-1}$ tha...

  13. Friction and wear behavior of carbon fiber reinforced brake materials

    Institute of Scientific and Technical Information of China (English)

    Du-qing CHENG; Xue-tao WANG; Jian ZHU; Dong-bua QIU; Xiu-wei CHENG; Qing-feng GUAN

    2009-01-01

    A new composite brake material was fabri-cated with metallic powders, barium sulphate and modified phenolic resin as the matrix and carbon fiber as the reinforced material. The friction, wear and fade character-istics of this composite were determined using a D-MS friction material testing machine. The surface structure of carbon fiber reinforced friction materials was analyzed by scanning electronic microscopy (SEM). Glass fiber-reinforced and asbestos fiber-reinforced composites with the same matrix were also fabricated for comparison. The carbon fiber-reinforced friction materials (CFRFM) shows lower wear rate than those of glass fiber- and asbestos fiber-reinforced composites in the temperature range of 100℃-300℃. It is interesting that the frictional coefficient of the carbon fiber-reinforced friction materials increases as frictional temperature increases from 100℃ to 300℃, while the frictional coefficients of the other two composites decrease during the increasing temperatures. Based on the SEM observation, the wear mechanism of CFRFM at low temperatures included fiber thinning and pull-out. At high temperature, the phenolic matrix was degraded and more pull-out enhanced fiber was demonstrated. The properties of carbon fiber may be the main reason that the CFRFM possess excellent tribological performances.

  14. Line short circuit detection by d.c. motor vehicles with regenerative braking equipment; Streckenkurzschlusserkennung in rueckspeisenden Gleichstromtriebfahrzeugen

    Energy Technology Data Exchange (ETDEWEB)

    Loesel, T.; Roehling, S. [elbas Elektrische Bahnsysteme Ingenieurgesellschaft mbH, Dresden (Germany)

    1996-12-31

    Line short circuits which occur during regenerative braking of traction vehicles cannot be detected reliably by conventional d.c. substation equipment. A method will be described how braking d.c. traction vehicles can detect a line short circuit and as a consequence interrupt regenerative braking. Unnecessary triggering can be detected and braking restored. Design and experiences will be presented. (orig.) [Deutsch] Die Erkennung von Streckenkurzschluessen, die waehrend des Einsatzes der Netzbremse auftreten, ist im Unterwerk nicht immer moeglich. Es wird ein Verfahren beschrieben, mit dem das bremsende Fahrzeug einen Kurzschluss selbst erkennt und die Netzbremsung daraufhin unterbricht. Das Verfahren kann Fehlausloesungen feststellen und zuruecknehmen. (orig.)

  15. 21 CFR 890.3790 - Cane, crutch, and walker tips and pads.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Cane, crutch, and walker tips and pads. 890.3790... (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Prosthetic Devices § 890.3790 Cane, crutch, and walker tips and pads. (a) Identification. Cane, crutch, and walker tips and pads are...

  16. 77 FR 50508 - Brain-Pad, Inc; Analysis of Proposed Consent Order To Aid Public Comment

    Science.gov (United States)

    2012-08-21

    ... Brain-Pad, Inc; Analysis of Proposed Consent Order To Aid Public Comment AGENCY: Federal Trade... SUPPLEMENTARY INFORMATION section below. Write ``Brain-Pad, File No. 122 3073'' on your comment, and file your... must receive it on or before September 17, 2012. Write ``Brain-Pad, File No. 122 3073'' on your...

  17. Inclination angle and braking index evolution of pulsars with plasma-filled magnetosphere: application to high braking index of PSR J1640-4631

    CERN Document Server

    Ekşi, Kazım Yavuz; Çıkıntoğlu, Sercan; Gügercinoğlu, Erbil; Motlagh, Armin Vahdat; Kızıltan, Bülent

    2016-01-01

    The recently discovered rotationally powered pulsar PSR J1640-4631 is the first to have a braking index measured, with high enough precision, to be greater than three. An inclined magnetic rotator in vacuum or plasma would be subject to not only spin-down torque but also to an alignment torque. The vacuum model can address the braking index only for an almost orthogonal rotator which is incompatible with the single peaked pulse profile. We show that the magnetic dipole model with the corotating plasma predicts braking indices between $3-3.25$ and can explain the braking index of $3.15$ for two different inclination angles, $18.5\\pm 3$ degrees and $56 \\pm 4$ degrees. Of these the former is preferred given the pulse profile has a single peak. We infer the change in the inclination angle to be at the rate $-0.23$ degrees per century, three times smaller in absolute value than the rate recently observed from the Crab pulsar.

  18. On the potential of uncertainty analysis for prediction of brake squeal propensity

    Science.gov (United States)

    Zhang, Zhi; Oberst, Sebastian; Lai, Joseph C. S.

    2016-09-01

    Brake squeal is a source of significant warranty-related claims for automotive manufacturers because it is annoying and is often perceived by customers as a safety concern. A brake squeal analysis is complex due to changing environmental and operating conditions, high sensitivity to manufacturing and assembly tolerances as well as the not so well understood role of nonlinearities. Although brake squeal is essentially a nonlinear problem, the standard analysis tool in industry is the linear complex eigenvalue analysis (CEA) which may under-predict or over-predict the number of unstable vibration modes. A nonlinear instability analysis is more predictive than CEA but is still computationally too expensive to be used routinely in industry for a full brake finite element model. Also, although the net work analysis of a linearised brake system has shown potential in predicting the origin of brake squeal, it has not been extensively used. In this study, the net work of an analytical viscously damped self-excited 4-dof friction oscillator with cubic contact force nonlinearity is compared with the instability prediction using the CEA and a nonlinear instability analysis. Results show that both the net work analysis and CEA under-predict the instability because of their inability to detect the sub-critical Hopf bifurcation. Then, the uncertainty analysis is applied to examine if it can improve instability prediction of a nonlinear system using linear methods and its limitations. By applying a variance-based global sensitivity analysis to parameters of the oscillator, suitable candidates for an uncertainty analysis are identified. Results of uncertainty analyses by applying polynomial chaos expansions to net work and CEA correlate well with those of the nonlinear analysis, hence demonstrating the potential of an uncertainty analysis in improving the prediction of brake squeal propensity using a linear method.

  19. Detection of braking intention in diverse situations during simulated driving based on EEG feature combination

    Science.gov (United States)

    Kim, Il-Hwa; Kim, Jeong-Woo; Haufe, Stefan; Lee, Seong-Whan

    2015-02-01

    Objective. We developed a simulated driving environment for studying neural correlates of emergency braking in diversified driving situations. We further investigated to what extent these neural correlates can be used to detect a participant's braking intention prior to the behavioral response. Approach. We measured electroencephalographic (EEG) and electromyographic signals during simulated driving. Fifteen participants drove a virtual vehicle and were exposed to several kinds of traffic situations in a simulator system, while EEG signals were measured. After that, we extracted characteristic features to categorize whether the driver intended to brake or not. Main results. Our system shows excellent detection performance in a broad range of possible emergency situations. In particular, we were able to distinguish three different kinds of emergency situations (sudden stop of a preceding vehicle, sudden cutting-in of a vehicle from the side and unexpected appearance of a pedestrian) from non-emergency (soft) braking situations, as well as from situations in which no braking was required, but the sensory stimulation was similar to stimulations inducing an emergency situation (e.g., the sudden stop of a vehicle on a neighboring lane). Significance. We proposed a novel feature combination comprising movement-related potentials such as the readiness potential, event-related desynchronization features besides the event-related potentials (ERP) features used in a previous study. The performance of predicting braking intention based on our proposed feature combination was superior compared to using only ERP features. Our study suggests that emergency situations are characterized by specific neural patterns of sensory perception and processing, as well as motor preparation and execution, which can be utilized by neurotechnology based braking assistance systems.

  20. iPad for the Older and Wiser Get Up and Running Safely and Quickly with the Apple iPad

    CERN Document Server

    McManus, Sean

    2011-01-01

    Easy-to-follow, friendly advice on using the iPad 2 This heavily illustrated, approachable guide for the anyone over 50 provides a solid resource for learning how to use the iPad in everyday situations. Veteran author and technology expert Sean McManus clearly explains how to use the iPad to send e-mails, listen to music, watch movies, and play games. Detailed coverage walks you step by step through setting up and registering your iPad, connecting to the Internet, syncing your iPad to other devices, and much more. The iPad is an ideal companion for making your life easier, and this friendly gu