Sample records for hydraulic power pack

  1. Power assisted hydraulic control

    SciTech Connect

    Dauvergne, J.L.R.

    1984-05-22

    The invention provides a power assisted hydraulic control system suitable for actuating clutches and brakes. The system incorporates a master cylinder having a master piston therein defining a control chamber, a hydraulic power assistance unit, and a distributor adapted to connect, by means of a slide valve, the power assistance unit with the hydraulic receiver controlling the brake or clutch unit. The distributor comprises a slide-valve having a plunger one end of which is subjected to the pressure in the control chamber and the other end of which is subjected to the pressure in the receiver. A bypass channel links the control chamber of the master cylinder to the pipeline connecting the operating port of the distributor to the receiver. The bypass channel has a bypass valve controlled by a spring which opens in the event of failure of the power assistance to permit manual operation by the master piston.

  2. Recover Power with Hydraulic Motors

    E-print Network

    Brennan, J. R.

    1982-01-01

    displacement device, the HPRM torque and speed are almost completely independent - unlike hydraulic power recovery turbines (centrifugal motors). Three screw HPRM's have low moments of inertia, operate at low vibration and noise levels and extract power...

  3. Fluid Power/Basic Hydraulics. Instructor's Guide.

    ERIC Educational Resources Information Center

    Stanbery, Richard

    This guide is designed to assist industrial vocational instructors in teaching a course on fluid power and basic hydraulics. Covered in the unit on the basics of fluid power and hydraulics are the following topics: the fundamentals of fluid power and hydraulics, basic hydraulic circuits, and servicing a hydraulic jack. The second unit, consisting…

  4. Hydraulic Wind Power Transfer Technology Afshin Izadian

    E-print Network

    Zhou, Yaoqi

    Hydraulic Wind Power Transfer Technology Afshin Izadian Purdue School of Engineering and Technology wind power, and by doing so, it reduces the capital equipment of the entire power plant to regulate the wind power and load variations. #12;

  5. Power Consumption Prediction and Power-Aware Packing in Consolidated

    E-print Network

    Urgaonkar, Bhuvan

    Power Consumption Prediction and Power-Aware Packing in Consolidated Environments Jeonghwan Choi the power consumption of groups of colocated applications. Such characterization is crucial for effective prediction and enforcement of appropriate limits on power consumption--power budgets--within the data center

  6. Space Shuttle Upgrades Advanced Hydraulic Power System

    NASA Technical Reports Server (NTRS)

    2004-01-01

    Three Auxiliary Power Units (APU) on the Space Shuttle Orbiter each provide 145 hp shaft power to a hydraulic pump which outputs 3000 psi hydraulic fluid to 41 hydraulic actuators. A hydrazine fuel powered APU utilized throughout the Shuttle program has undergone many improvements, but concerns remain with flight safety, operational cost, critical failure modes, and hydrazine related hazards. The advanced hydraulic power system (AHPS), also known as the electric APU, is being evaluated as an upgrade to replace the hydrazine APU. The AHPS replaces the high-speed turbine and hydrazine fuel supply system with a battery power supply and electric motor/pump that converts 300 volt electrical power to 3000 psi hydraulic power. AHPS upgrade benefits include elimination of toxic hydrazine propellant to improve flight safety, reduction in hazardous ground processing operations, and improved reliability. Development of this upgrade provides many interesting challenges and includes development of four hardware elements that comprise the AHPS system: Battery - The battery provides a high voltage supply of power using lithium ion cells. This is a large battery that must provide 28 kilowatt hours of energy over 99 minutes of operation at 300 volts with a peak power of 130 kilowatts for three seconds. High Voltage Power Distribution and Control (PD&C) - The PD&C distributes electric power from the battery to the EHDU. This 300 volt system includes wiring and components necessary to distribute power and provide fault current protection. Electro-Hydraulic Drive Unit (EHDU) - The EHDU converts electric input power to hydraulic output power. The EHDU must provide over 90 kilowatts of stable, output hydraulic power at 3000 psi with high efficiency and rapid response time. Cooling System - The cooling system provides thermal control of the Orbiter hydraulic fluid and EHDU electronic components. Symposium presentation will provide an overview of the AHPS upgrade, descriptions of the four hardware elements, and a summary of development results to date.

  7. Activity Packing in FPGAs for Leakage Power Reduction

    Microsoft Academic Search

    Hassan Hassan; Mohab Anis; Antoine El Daher Mohamed

    In this paper, two packing algorithms for the detection of ac- tivity profiles in MTCMOS-based FPGA structures are proposed for leakage power mitigation. The first algorithm is a connection- based packing technique by which the proximity of the logic blocks is accounted for, and the second algorithm is a logic-based pack- ing approach by which the weighted Hamming distance between

  8. Tiny hydraulics for powered orthotics.

    PubMed

    Durfee, William; Xia, Jicheng; Hsiao-Wecksler, Elizabeth

    2011-01-01

    Untethered, powered orthotics require an actuation system with power supply and control, transmission line and actuator. Fluid power has unmatched force-to-weight and power-to-weight compared to electromechanical systems, but it is unclear if those same advantages hold for small systems in the 10 to 100 W range. A systems analysis approach suggests that a fluid power system will be lighter than an electromechanical system with the same output power and efficiency if the fluid power is run at pressures over about 200 psi. A theoretical analysis of small bore cylinders suggests that eliminating the piston seal will result in a higher efficiency actuator if the clearance gap is small. A demonstration, battery powered electrohydraulic actuator assembled from off-the-shelf components had the force and power suited to a powered ankle orthosis, but is too large and too heavy, suggesting the need to develop custom components. PMID:22275671

  9. Autoerotic fatalities with power hydraulics.

    PubMed

    O'Halloran, R L; Dietz, P E

    1993-03-01

    We report two cases in which men used the hydraulic shovels on tractors to suspend themselves for masochistic sexual stimulation. One man developed a romantic attachment to a tractor, even giving it a name and writing poetry in its honor. He died accidentally while intentionally asphyxiating himself through suspension by the neck, leaving clues that he enjoyed perceptual distortions during asphyxiation. The other man engaged in sexual bondage and transvestic fetishism, but did not purposely asphyxiate himself. He died when accidentally pinned to the ground under a shovel after intentionally suspending himself by the ankles. We compare these cases with other autoerotic fatalities involving perceptual distortion, cross-dressing, machinery, and postural asphyxiation by chest compression. PMID:8454997

  10. Experimental Studies of Wave Hydraulic Power Units

    Microsoft Academic Search

    V. P. Drobakhin; N. D. Nolirovskaya; V. A. Osadchuk; A. V. Savchenko

    2003-01-01

    At the Ukrgidroproekt Joint-Stock Co. (Kharkov), research and development studies concerned with the use of wave energy have been conducted over a period of years. Under a Reseacrh and Developement program in 1994 – 1995, a model of a wave power plant was tested at a laboratory for large-scale hydraulic and geotechnic studies (LHGSL, Dneprodzerzhinsk) and promising results were obtained

  11. 8. HIGH POWER SPRAY IN MEN'S PACK ROOM. Hot ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    8. HIGH POWER SPRAY IN MEN'S PACK ROOM. - Hot Springs National Park Bathhouse Row, Maurice Bathhouse: Mechanical & Piping Systems, State Highway 7, 1 mile north of U.S. Highway 70, Hot Springs, Garland County, AR

  12. Lightweight, Flexible, Thin, Integrated Solar-Power Packs

    NASA Technical Reports Server (NTRS)

    Hanson, Robert R.

    2004-01-01

    Lightweight, flexible, thin, one-piece, solar-power packs are undergoing development. Each power pack of this type is a complete, modular, integrated power-supply system comprising three power subsystems that, in conventional practice, have been constructed as separate units and connected to each other by wires. These power packs are amenable to a variety of uses: For example, they could be laminated to the tops of tents and other shelters to provide or augment power for portable electronic equipment in the field, and they could be used as power sources for such small portable electronic systems as radio transceivers (including data relays and cellular telephones), laptop computers, video camcorders, and Global Positioning System receivers.

  13. Centre Hydraulic Power Supply Unit University of Saskatchewan -Mechanical Engineering Fluid Power and Controls

    E-print Network

    Saskatchewan, University of

    Centre Hydraulic Power Supply Unit University of Saskatchewan - Mechanical Engineering ­ Fluid Power and Controls ID: FP0003 Rev: 001 Date: May 31, 2010 Page: 1 of 7 Centre Hydraulic Power Supply;Centre Hydraulic Power Supply Unit University of Saskatchewan - Mechanical Engineering ­ Fluid Power

  14. HYPower Hydraulic Power Supply Unit University of Saskatchewan -Mechanical Engineering Fluid Power and Controls

    E-print Network

    Saskatchewan, University of

    HYPower Hydraulic Power Supply Unit University of Saskatchewan - Mechanical Engineering ­ Fluid Power and Controls ID: FP0002 Rev: 002 Date: May 31, 2010 Page: 1 of 7 Hydraulic Power Supply (HYPower-5462 Secondary Contact: #12;HYPower Hydraulic Power Supply Unit University of Saskatchewan - Mechanical

  15. East Hydraulic Power Supply Unit University of Saskatchewan -Mechanical Engineering Fluid Power and Controls

    E-print Network

    Saskatchewan, University of

    East Hydraulic Power Supply Unit University of Saskatchewan - Mechanical Engineering ­ Fluid Power and Controls ID: FP0004 Rev: 001 Date: May 31, 2010 Page: 1 of 7 East Hydraulic Power Supply and Test Bench. Approved By: Primary Contact: Doug Bitner Rm: 1B15.1 966-5462 Secondary Contact: #12;East Hydraulic Power

  16. Control\\/structure interaction in hydraulic power steering systems

    Microsoft Academic Search

    Gary R. Ferries; R. Larry Arbanas

    1997-01-01

    A hydraulic power steering system uses feedback control to assist the driver in applying steering input commands to the vehicle. A small vibration, known as shudder, can occur in the system during low speed steering manoeuvres. It is shown that power steering shudder is a closed-loop limit cycle caused by the interaction of the hydraulic and structural dynamics of the

  17. Control issues for a hydraulically powered dissimilar teleoperated system

    SciTech Connect

    Jansen, J.F.; Kress, R.L.

    1995-12-31

    This paper will address two issues associated with the implementation of a hydraulically powered dissimilar master-slave teleoperated system. These issues are the overall system control architecture and the design of robust hydraulic servo controllers for the position control problem. Finally, a discussion of overall system performance on an actual teleoperated system will be presented. (Schilling`s Titan II hydraulic manipulators are the slave manipulators and the master manipulators are from the Oak Ridge National Laboratory-developed Advanced Servo Manipulator.)

  18. Analysis of response lag in hydraulic power steering system

    Microsoft Academic Search

    Shinji Nishimura; Tsugiharu Matsunaga

    2000-01-01

    Response lag during rapid steering in the hydraulic power steering system of a vehicle was analyzed with a numerical simulation mathematical model which considered the propagation of pressure waves in a hydraulic line and visco-elastic characteristics of the hose. Pressure perturbation by pump flow ripple and self-excited vibration which were incompatible with the response, were analyzed by the simulation. From

  19. Hydraulics.

    ERIC Educational Resources Information Center

    Decker, Robert L.; Kirby, Klane

    This curriculum guide contains a course in hydraulics to train entry-level workers for automotive mechanics and other fields that utilize hydraulics. The module contains 14 instructional units that cover the following topics: (1) introduction to hydraulics; (2) fundamentals of hydraulics; (3) reservoirs; (4) lines, fittings, and couplers; (5)…

  20. Hybrid hydraulic-electric power unit for field and service robots

    Microsoft Academic Search

    Kurt Amundson; Justin Raade; Nathan Harding; H. Kazerooni

    2005-01-01

    Energetic autonomy of a hydraulic-based mobile field robot requires a power source capable of both electrical and hydraulic power generation. While the hydraulic power is used for locomotion, the electric power is used for the computer, sensors and other peripherals. An internal combustion engine was used as the prime mover due to the high energy density of gasoline. The primary

  1. Hydraulics.

    ERIC Educational Resources Information Center

    Engelbrecht, Nancy; And Others

    These instructional materials provide an orientation to hydraulics for use at the postsecondary level. The first of 12 sections presents an introduction to hydraulics, including discussion of principles of liquids, definitions, liquid flow, the two types of hydraulic fluids, pressure gauges, and strainers and filters. The second section identifies…

  2. Low-power microfluidic electro-hydraulic pump (EHP).

    PubMed

    Lui, Clarissa; Stelick, Scott; Cady, Nathaniel; Batt, Carl

    2010-01-01

    Low-power electrolysis-based microfluidic pumps utilizing the principle of hydraulics, integrated with microfluidic channels in polydimethylsiloxane (PDMS) substrates, are presented. The electro-hydraulic pumps (EHPs), consisting of electrolytic, hydraulic and fluidic chambers, were investigated using two types of electrodes: stainless steel for larger volumes and annealed gold electrodes for smaller-scale devices. Using a hydraulic fluid chamber and a thin flexible PDMS membrane, this novel prototype successfully separates the reagent fluid from the electrolytic fluid, which is particularly important for biological and chemical applications. The hydraulic advantage of the EHP device arises from the precise control of flow rate by changing the electrolytic pressure generated, independent of the volume of the reagent chamber, mimicking the function of a hydraulic press. Since the reservoirs are pre-filled with reagents and sealed prior to testing, external fluid coupling is minimized. The stainless steel electrode EHPs were manufactured with varying chamber volume ratios (1 : 1 to 1 : 3) as a proof-of-concept, and exhibited flow rates of 1.25 to 30 microl/min with electrolysis-based actuation at 2.5 to 10 V(DC). The miniaturized gold electrode EHPs were manufactured with 3 mm diameters and 1 : 1 chamber volume ratios, and produced flow rates of 1.24 to 7.00 microl/min at 2.5 to 10 V(AC), with a higher maximum sustained pressure of 343 KPa, suggesting greater device robustness using methods compatible with microfabrication. The proposed technology is low-cost, low-power and disposable, with a high level of reproducibility, allowing for ease of fabrication and integration into existing microfluidic lab-on-a-chip and analysis systems. PMID:20024053

  3. Nonlinear State Space Model of a Hydraulic Wind Power Transfer Masoud Vaezi1

    E-print Network

    Zhou, Yaoqi

    Nonlinear State Space Model of a Hydraulic Wind Power Transfer Masoud Vaezi1 , Majid Deldar1 1, IUPUI. Gearless hydraulic wind power systems are considered as nonlinear models because of some discrete nonlinear governing equations for the elements in the proposed hydraulic wind power configuration. Nonlinear

  4. 46 CFR 128.240 - Hydraulic or pneumatic power and control-materials and pressure design.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...2010-10-01 2010-10-01 false Hydraulic or pneumatic power and control-materials...Materials and Pressure Design § 128.240 Hydraulic or pneumatic power and control—materials...flanges, and standard valves) for hydraulic or pneumatic power and control...

  5. 49 CFR 173.172 - Aircraft hydraulic power unit fuel tank.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...2010-10-01 2010-10-01 false Aircraft hydraulic power unit fuel tank. 173.172 Section...Class 1 and Class 7 § 173.172 Aircraft hydraulic power unit fuel tank. Aircraft hydraulic power unit fuel tanks containing a...

  6. International Space Station power module thermal control system hydraulic performance

    SciTech Connect

    Goldberg, V. [Boeing North American, Inc., Canoga Park, CA (United States). Rocketdyne Div.

    1997-12-31

    The International Space Station (ISS) uses four photovoltaic power modules (PVMs) to provide electric power for the US On-Orbit Segment. The PVMs consist of photovoltaic arrays (PVAs), orbit replaceable units (ORUs), photovoltaic radiators (PVRs), and a thermal control system (TCS). The PVM TCS function is to maintain selected PVM components within their specified operating ranges. The TCS consists of the pump flow control subassembly (PFCS), piping system, including serpentine tubing for individual component heat exchangers, headers/manifolds, fluid disconnect couplings (FQDCs), and radiator (PVR). This paper describes the major design requirements for the TCS and the results of the system hydraulic performance predictions in regard to these requirements and system component sizing. The system performance assessments were conducted using the PVM TCS fluid network hydraulic model developed for predicting system/component pressure losses and flow distribution. Hardy-Cross method of iteration was used to model the fluid network configuration. Assessments of the system hydraulic performance were conducted based on an evaluation of uncertainties associated with the manufacturing and design tolerances. Based on results of the analysis, it was concluded that all design requirements regarding system performance could be met. The hydraulic performance range, enveloping possible system operating parameter variations was determined.

  7. Powered orthosis and attachable power-assist device with Hydraulic Bilateral Servo System.

    PubMed

    Ohnishi, Kengo; Saito, Yukio; Oshima, Toru; Higashihara, Takanori

    2013-01-01

    This paper discusses the developments and control strategies of exoskeleton-type robot systems for the application of an upper limb powered orthosis and an attachable power-assist device for care-givers. Hydraulic Bilateral Servo System, which consist of a computer controlled motor, parallel connected hydraulic actuators, position sensors, and pressure sensors, are installed in the system to derive the joint motion of the exoskeleton arm. The types of hydraulic component structure and the control strategy are discussed in relation to the design philosophy and target joints motions. PMID:24110321

  8. A NEW PASSIVE CONTROLLER FOR A HYDRAULIC HUMAN POWER AMPLIFIER Perry Y. Li

    E-print Network

    Li, Perry Y.

    A NEW PASSIVE CONTROLLER FOR A HYDRAULIC HUMAN POWER AMPLIFIER Perry Y. Li Department of Mechanical A new, intrinsically passive controller for hydraulic human power amplifier is presented. The hydraulic. The control objective is to cause the system to behave like a passive mechanical tool when interacting

  9. Simulation and experimental validation study on the drive performance of a new hydraulic power assist system

    Microsoft Academic Search

    Guo-Qing Liu; Ye-Cui Yan; Jie Chen; Tian-Ming Na

    2009-01-01

    Hydraulic power assist system is a hydraulic regeneration system, which can improve fuel economy significantly coupled to a conventional bus operating in urban traffic. This paper presents a new hydraulic power assist system-HPAS. For the special configuration and control strategy, HPAS can be easily installed in an old bus as well as a new one. In this paper, more attention

  10. 46 CFR 111.97-5 - Electric and hydraulic power supply.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...2010-10-01 false Electric and hydraulic power supply. 111.97-5 Section...Systems § 111.97-5 Electric and hydraulic power supply. (a) Each electric...operated watertight door system that uses a hydraulic system common to more than one...

  11. Hydraulics.

    ERIC Educational Resources Information Center

    Decker, Robert L.

    Designed for use in courses where students are expected to become proficient in the area of hydraulics, including diesel engine mechanic programs, this curriculum guide is comprised of fourteen units of instruction. Unit titles include (1) Introduction, (2) Fundamentals of Hydraulics, (3) Reservoirs, (4) Lines, Fittings, and Couplers, (5) Seals,…

  12. Analysis and design of a novel hydraulic power source for mobile robots

    Microsoft Academic Search

    Justin W. Raade; H. Kazerooni

    2005-01-01

    We have developed a novel device to supply hydraulic power for anaerobic mobile robotic systems. This power source demonstrates the possibility of operation in oxygen-free environments, such as underwater or in space. Unlike the internal combustion engine, the design produces power on demand, eliminating idling when there is no load on the system. This monopropellant-powered free piston hydraulic pump (FPHP)

  13. Hydraulics

    NSDL National Science Digital Library

    These interactive learning objects, created by instructors from Fox Valley Technical College and other colleges in the Wisconsin Technical College program, focus on concepts that cover a broad-based electromechanical program. Here visitors will find learning objects in Hydraulics with over 25 lessons in Actuators, Relief Valves, Basic Concepts, and Directional Control Valves.

  14. Hydraulic turbines for electric power generation. (Latest citations from the NTIS bibliographic database). Published Search

    SciTech Connect

    Not Available

    1993-12-01

    The bibliography contains citations concerning the design, construction and applications of hydraulic turbines used for electric power generation. Erosion, corrosion, fatigue cracking, cavitation and runners in hydraulic turbines are discussed. Performance evaluations for design innovations of hydraulic turbomachinery for underground pumped hydroelectric storage of regulated and unregulated turbines as well as vibration analysis of hydro units in hydroelectric power plants are included. (Contains a minimum of 142 citations and includes a subject term index and title list.)

  15. FUTURE POWER GRID INITIATIVE GridPACK: Grid Parallel Advanced

    E-print Network

    in Focus Area Two will use high-throughput data streams produced by projects in Focus Area One Pacific Northwest National Laboratory (509) 375-3899 bruce.palmer@pnnl.gov ABOUT FPGI The Future Power Operations Center (EIOC), the Pacific Northwest National Laboratory's (PNNL) national electric grid research

  16. Research on new automobile power hydraulic braking system by vibratory energy

    Microsoft Academic Search

    Ding Zhi-hua; Lei Zheng-bao; Lei Mu-xi

    2011-01-01

    A new automobile power hydraulic braking system by vibratory energy is introduced which includes four vibration dampers, four energy accumulators, hydraulic booster, one storage tank, four wheel cylinders, four electromagnetic one-way valves, brake master cylinder, vacuum booster, brake pedal and loading sensing pressure proportioning valve(LSPV). Vibration damper is composed of nitrogen cavity, piston, piston rod, shell, rebound valve, compression valve,

  17. Geomorphological and hydrological implications of a given hydraulic geometry relationship, beyond the power-law

    NASA Astrophysics Data System (ADS)

    Kim, JongChun; Paik, Kyungrock

    2015-04-01

    Channel geometry and hydraulic characteristics of a given river network, i.e., spatio-temporal variability of width, depth, and velocity, can be described as power functional relationships of flow discharge, named 'hydraulic geometry' (Leopold and Maddock, 1953). Many studies have focused on the implication of this power-law itself, i.e., self-similarity, and accordingly its exponents. Coefficients of the power functional relationships, on the contrary, have received little attention. They are often regarded as empirical constants, determined by 'best fitting' to the power-law without significant scientific implications. Here, we investigate and claim that power-law coefficients of hydraulic geometry relationships carry vital information of a given river system. We approach the given problem on the basis of 'basin hydraulic geometry' formulation (Stall and Fok, 1968) which decomposes power-law coefficients into more elementary constants. The linkage between classical power-law relationship (Leopold and Maddock, 1953) and the basin hydraulic geometry is provided by Paik and Kumar (2004). On the basis of this earlier study, it can be shown that coefficients and exponents of power-law hydraulic geometry are interrelated. In this sense, we argue that more elementary constants that constitute both exponents and coefficients carry important messages. In this presentation, we will demonstrate how these elementary constants vary over a wide range of catchments provided from Stall and Fok (1968) and Stall and Yang (1970). Findings of this study can provide new insights on fundamental understanding about hydraulic geometry relationships. Further, we expect that this understanding can help interpretation of hydraulic geometry relationship in the context of flood propagation through a river system as well. Keywords: Hydraulic geometry; Power-law; River network References Leopold, L. B., & Maddock, T. J. (1953). The hydraulic geometry of stream channels and some physiographic implications. U. S. Geological Survey Professional Paper, 252. Paik, K., & Kumar, P. (2004). Hydraulic geometry and the nonlinearity of the network instantaneous response, Water Resource Research, 40, W03602. Stall, J. B., & Fok, Y. S. (1968). Hydraulic geometry of Illinois streams. University of Illinois Water Resources Center Research Report, 15. Stall, J. B., & Yang, C. T. (1970). Hydraulic geometry of 12 selected stream systems of the United States. University of Illinois Water Resources Center Research Report, 32.

  18. NEUTRONIC AND THERMAL HYDRAULIC DESIGNS OF ANNULAR FUEL FOR HIGH POWER DENSITY BWRS

    E-print Network

    Morra, P.

    As a promising new fuel for high power density light water reactors, the feasibility of using annular fuel for BWR services is explored from both thermal hydraulic and neutronic points of view. Keeping the bundle size ...

  19. Base-Bleed Effect on X-33 Aerospike Plume Induced Base-Heating Environment During Power-Pack Out

    NASA Technical Reports Server (NTRS)

    Wang, Tee-See; Droege, Alan; D'Agostino, Mark; Lee, Young-Ching; Williams, Robert

    2003-01-01

    A computational heat transfer methodology was developed to study the dual-engine linear aerospike plume induced base-heating environment during one power-pack out, in ascent flight. One power-pack out results in reduction of power levels for both engines. That, in turn, reduces the amount of base-bleed and changes the distribution of base-bleed on the two pillows. Hence, the concern of increased base-heating during power-pack out. The thermo-flowfield of the entire vehicle was computed. The computational methodology for the convective heating is based on a three-dimensional, finite-volume, viscous, chemically reacting, and pressure-based computational fluid dynamics formulation. The computational methodology for the radiative heating is based on a three-dimensional, finite-volume, and spectral-line-based weighted-sum-of-gray-gases absorption computational radiation heat transfer formulation. A separate radiation model was used for diagnostic purposes. The computational methodology was systematically benchmarked. In this study, near-base radiative heat fluxes were computed and they compared well with those measured from an installed linear aerospike engine tests. The base-heating environment of 18 trajectory points selected from three power-pack out ascent scenarios was computed and is presented here. The power-pack out condition has the most impact on convective base-heating when it happens early in flight. The some of its impact comes from the asymmetric and reduced base-bleed.

  20. Anaerobic treatment of rice winery wastewater in an upflow filter packed with steel slag under different hydraulic loading conditions.

    PubMed

    Jo, Yeadam; Kim, Jaai; Hwang, Seokhwan; Lee, Changsoo

    2015-10-01

    Rice-washing drainage (RWD), a strong organic wastewater, was anaerobically treated using an upflow filter filled with blast-furnace slag. The continuous performance of the reactor was examined at varying hydraulic retention times (HRTs). The reactor achieved 91.7% chemical oxygen demand removal (CODr) for a 10-day HRT (0.6gCOD/Ld organic loading rate) and maintained fairly stable performance until the HRT was shortened to 2.2days (CODr>84%). Further decreases in HRT caused process deterioration (CODr<50% and pH<5.5 for a 0.7-day HRT). The methane production rate increased with decreasing HRT to reach the peak level for a 1.3-day HRT, whereas the yield was significantly greater for 3.4-day or longer HRTs. The substrate removal and methane production kinetics were successfully evaluated, and the generated kinetic models produced good performance predictions. The methanogenic activity of the reactor likely relies on the filter biofilm, with Methanosaeta being the main driver. PMID:26117235

  1. Packings with large minimum kissing numbers For each proper power of 4, n, we describe a simple explicit construction of a finite collection

    E-print Network

    Shamir, Ron

    Packings with large minimum kissing numbers Noga Alon Abstract For each proper power of 4, n, we if the centers of the balls form a lattice in Rn. The minimum kissing number of a packing is the minimum number and construction of lattice packings with high kissing numbers received a considerable amount of attention

  2. Survey of thermal-hydraulic models of commercial nuclear power plants

    SciTech Connect

    Determan, J.C.; Hendrix, C.E.

    1992-12-01

    A survey of the thermal-hydraulic models of nuclear power plants has been performed to identify the NRC`s current analytical capabilities for critical event response. The survey also supports ongoing research for accident management. The results of the survey are presented here. The PC database which records detailed data on each model is described.

  3. Survey of thermal-hydraulic models of commercial nuclear power plants

    SciTech Connect

    Determan, J.C.; Hendrix, C.E.

    1992-12-01

    A survey of the thermal-hydraulic models of nuclear power plants has been performed to identify the NRC's current analytical capabilities for critical event response. The survey also supports ongoing research for accident management. The results of the survey are presented here. The PC database which records detailed data on each model is described.

  4. Modeling and Simulation of Dynamic Characteristics of a Bipropellant-Powered Hydraulic Free Piston Engine

    Microsoft Academic Search

    Bizhong Xia; Xiaoliang Li; Haibo Xie; Huayong Yang

    2011-01-01

    Bipropellant-powered hydraulic free piston engine (BHFPE) is a new type HFPE, which takes advantage of bipropellant in place of conventional fossil fuel, and employs catalytic ignition instead of spark or compression ignition. Under the alternative drive of the left and right combustion chamber, free piston assembly (FPA) within the BHFPE moves linearly back and forth between left and right extremes

  5. An Integrated Power Pack of Dye-Sensitized Solar Cell and Li Battery Based on Double-Sided TiO2 Nanotube Arrays

    E-print Network

    Wang, Zhong L.

    An Integrated Power Pack of Dye-Sensitized Solar Cell and Li Battery Based on Double-Sided TiO2 harvest and storage processes. This power pack incorporates a series-wound dye- sensitized solar cell material.11,15 Compared with other integrated solar power supplies,16,17 double-sided TiO2 NTs with large

  6. Design, simulation, and testing of a novel hydraulic power take-off system for the Pelamis wave energy converter

    Microsoft Academic Search

    Ross Henderson

    2006-01-01

    The economic viability of a wave energy converter depends largely on its power take-off system. Active control of the power take-off is necessary to maximise power capture across a range of sea-states and can also improve survivability. The high force, low speed regime of wave energy conversion makes it a suitable application for high-pressure hydraulics.This paper describes the hydraulic power

  7. Rechargeable hydraulic power source for actuating downhole tool

    SciTech Connect

    Schultz, R.L.

    1992-07-07

    This patent describes a downhole tool apparatus. It comprises a housing having a power chamber, a supply chamber and an isolation chamber defined therein, and having port means defined therein for communicating the isolation chamber with a low pressure zone of a well; a power transfer element disposed in the power chamber; a pressure transfer piston slidably disposed in the supply chamber and dividing the supply chamber into first and second portions; an isolation piston slidably disposed in the isolation chamber and dividing the isolation chamber into first and second portions; power passage means for communicating the power chamber with the first portion of the supply chamber and with the first portion of the isolation chamber.

  8. Preliminary evaluation of the use of hydraulic air compressors in water-compensated reservoir compressed air storage power plants

    Microsoft Academic Search

    F. W. Ahrens; J. A. Berghmans

    1978-01-01

    An air compression system for CAES applications, based on the hydraulic compressor principle, is described and evaluated. In addition to yielding a more efficient use of energy from the base power plant, due to isothermal air compression, the hydraulic air compressor does not require the conventional intercoolers and it replaces the air compressors with water pumps. Using performance characteristics predicted

  9. On-Shore Central Hydraulic Power Generation for Wind and Tidal Energy

    NASA Technical Reports Server (NTRS)

    Jones, Jack A.; Bruce, Allan; Lim, Steven; Murray, Luke; Armstrong, Richard; Kimball, Richard; Cook-Chenault, Kimberly; DeGennaro, Sean

    2012-01-01

    Tidal energy, offshore wind energy, and onshore wind energy can be converted to electricity at a central ground location by means of converting their respective energies into high-pressure hydraulic flows that are transmitted to a system of generators by high-pressure pipelines. The high-pressure flows are then efficiently converted to electricity by a central power plant, and the low-pressure outlet flow is returned. The Department of Energy (DOE) is presently supporting a project led by Sunlight Photonics to demonstrate a 15 kilowatt tidal hydraulic power generation system in the laboratory and possibly later submerged in the ocean. All gears and submerged electronics are completely eliminated.A second portion of this DOE project involves sizing and costing a 15 megawatt tidal energy system for a commercial tidal energy plant. For this task, Atlantis Resources Corporation's 18-m diameter demonstrated tidal blades are rated to operate in a nominal 2.6 m/sec tidal flow to produce approximately one megawatt per set of tidal blades. Fifteen units would be submerged in a deep tidal area, such as in Maine's Western Passage. All would be connected to a high-pressure (20 megapascals, 2900 pounds per square inch) line that is 35 cm ID. The high-pressure HEPG fluid flow is transported 500-m to on-shore hydraulic generators. HEPG is an environmentally-friendly, biodegradable, water-miscible fluid. Hydraulic adaptations to ORPC's cross-flow turbines are also discussed.For 15 megawatt of wind energy that is onshore or offshore, a gearless, high efficiency, radial piston pump can replace each set of top-mounted gear-generators. The fluid is then pumped to a central, easily serviceable generator location. Total hydraulic/electrical efficiency is 0.81 at full rated wind or tidal velocities and increases to 0.86 at 1/3 rated velocities.

  10. On-Shore Central Hydraulic Power Generation for Wind and Tidal Energy

    NASA Technical Reports Server (NTRS)

    Jones, Jack A.; Bruce, Allan; Lim, Steven; Murray, Luke; Armstrong, Richard; Kimbrall, Richard; Cook-Chenault, Kimberly; DeGennaro, Sean

    2012-01-01

    Tidal energy, offshore wind energy, and onshore wind energy can be converted to electricity at a central ground location by means of converting their respective energies into high-pressure hydraulic flows that are transmitted to a system of generators by high-pressure pipelines. The high-pressure flows are then efficiently converted to electricity by a central power plant, and the low-pressure outlet flow is returned. The Department of Energy (DOE) is presently supporting a project led by Sunlight Photonics to demonstrate a 15 kW tidal hydraulic power generation system in the laboratory and possibly later submerged in the ocean. All gears and submerged electronics are completely eliminated. A second portion of this DOE project involves sizing and costing a 15 MW tidal energy system for a commercial tidal energy plant. For this task, Atlantis Resources Corporation s 18-m diameter demonstrated tidal blades are rated to operate in a nominal 2.6 m/sec tidal flow to produce approximately one MW per set of tidal blades. Fifteen units would be submerged in a deep tidal area, such as in Maine s Western Passage. All would be connected to a high-pressure (20 MPa, 2900 psi) line that is 35 cm ID. The high-pressure HEPG fluid flow is transported 500-m to on-shore hydraulic generators. HEPG is an environmentally-friendly, biodegradable, watermiscible fluid. Hydraulic adaptations to ORPC s cross-flow turbines are also discussed. For 15 MW of wind energy that is onshore or offshore, a gearless, high efficiency, radial piston pump can replace each set of top-mounted gear-generators. The fluid is then pumped to a central, easily serviceable generator location. Total hydraulic/electrical efficiency is 0.81 at full rated wind or tidal velocities and increases to 0.86 at 1/3 rated velocities.

  11. Horizontal Steam Generator Thermal-Hydraulics at Various Steady-State Power Levels

    Microsoft Academic Search

    Vladimir D. Stevanovic; Zoran V. Stosic; Michael Kiera; Uwe Stoll

    2002-01-01

    Three-dimensional computer simulation and analyses of the horizontal steam generator thermal-hydraulics of the WWER 1000 nuclear power plant have been performed for 50% and 75% partial loads, 100% nominal load and 110% over-load. Presented results show water and steam mass flow rate vectors, steam void fraction spatial distribution, recirculation zones, swell level position, water mass inventory on the shell side,

  12. Vehicle having hydraulic and power steering systems using a single high pressure pump

    DOEpatents

    Bartley, Bradley E. (Manito, IL); Blass, James R. (Bloomington, IL); Gibson, Dennis H. (Chillicothe, IL)

    2001-06-22

    A vehicle comprises a plurality of wheels attached to a vehicle housing. Also attached to the vehicle housing is a power steering system, including a fluid flow circuit, which is operably coupled to a number of the wheels. An internal combustion engine attached to the vehicle housing is connected to a hydraulically actuated system that includes a high pressure pump. An outlet of the high pressure pump is in fluid communication with the fluid flow circuit.

  13. Analysis of hydraulic power transduction in regenerative rotary shock absorbers as function of working fluid kinematic viscosity

    E-print Network

    Avadhany, Shakeel N

    2009-01-01

    This investigation seeks to investigate the relationship of kinematic fluid viscosity to the effective power transduction seen by a hydraulic motor. Applications of this research specifically relate to energy recovery from ...

  14. [Application of ICP-AES in automotive hydraulic power steering system fault diagnosis].

    PubMed

    Chen, Li-Dan

    2013-01-01

    The authors studied the innovative applications of the inductively coupled plasma-atomic emission spectrometry in automotive hydraulic power steering system fault diagnosis. After having determined Fe, Cu and Al content in the four groups of Buick Regal 2.4 main metal power-steering fluid whose travel course was respectively 2-9 thousand kilometers, 11-18 thousand kilometers, 22-29 thousandkilometers, and 31-40 thousand kilometers, and the database of primary metal content in the Buick Regal 2.4 different mileage power-steering fluid was established. The research discovered that the main metal content increased with increasing mileage and its normal level is between the two trend lines. Determination of the power-steering fluid main metal content and comparison with its database value can not only judge the wear condition of the automotive hydraulic power steering system and maintain timely to avoid the traffic accident, but also help the automobile detection and maintenance personnel to diagnose failure reasons without disintegration. This reduced vehicle maintenance costs, and improved service quality. PMID:23586258

  15. Numerical Hydraulic Study on Seawater Cooling System of Combined Cycle Power Plant

    NASA Astrophysics Data System (ADS)

    Kim, J. Y.; Park, S. M.; Kim, J. H.; Kim, S. W.

    2010-06-01

    As the rated flow and pressure increase in pumping facilities, a proper design against surges and severe cavitations in the pipeline system is required. Pressure surge due to start-up, shut-down process and operation failure causes the water hammer in upstream of the closing valve and the cavitational hammer in downstream of the valve. Typical cause of water hammer is the urgent closure of valves by breakdown of power supply and unexpected failure of pumps. The abrupt changes in the flow rate of the liquid results in high pressure surges in upstream of the valves, thus kinetic energy is transformed into potential energy which leads to the sudden increase of the pressure that is called as water hammer. Also, by the inertia, the liquid continues to flow downstream of the valve with initial speed. Accordingly, the pressure decreases and an expanding vapor bubble known as column separation are formed near the valve. In this research, the hydraulic study on the closed cooling water heat exchanger line, which is the one part of the power plant, is introduced. The whole power plant consists of 1,200 MW combined power plant and 220,000 m3/day desalination facility. Cooling water for the plant is supplied by sea water circulating system with a capacity of 29 m3/s. The primary focus is to verify the steady state hydraulic capacity of the system. The secondary is to quantify transient issues and solutions in the system. The circuit was modeled using a commercial software. The stable piping network was designed through the hydraulic studies using the simulation for the various scenarios.

  16. Thermal-hydraulics and safety analysis of sectored compact reactor for lunar surface power

    SciTech Connect

    Schriener, T. M. [Inst. for Space and Nuclear Power Studies, Univ. of New Mexico, Albuquerque, NM (United States); Chemical and Nuclear Engineering Dept., Univ. of New Mexico, Albuquerque, NM (United States); El-Genk, M. S. [Inst. for Space and Nuclear Power Studies, Univ. of New Mexico, Albuquerque, NM (United States); Chemical and Nuclear Engineering Dept., Univ. of New Mexico, Albuquerque, NM (United States); Mechanical Engineering Dept., Univ. of New Mexico, Albuquerque, NM (United States)

    2012-07-01

    The liquid NaK-cooled, fast-neutron spectrum, Sectored Compact Reactor (SCoRe-N 5) concept has been developed at the Univ. of New Mexico for lunar surface power applications. It is loaded with highly enriched UN fuel pins in a triangular lattice, and nominally operates at exit and inlet coolant temperatures of 850 K and 900 K. This long-life reactor generates up to 1 MWth continuously for {>=} 20 years. To avoid a single point failure in reactor cooling, the core is divided into 6 sectors that are neutronically and thermally coupled, but hydraulically independent. This paper performs a 3-D the thermal-hydraulic analysis of SCoRe--N 5 at nominal operation temperatures and a power level of 1 MWth. In addition, the paper investigates the potential of continuing reactor operation at a lower power in the unlikely event that one sector in the core experiences a loss of coolant (LOC). Redesigning the core with a contiguous steel matrix enhances the cooling of the sector experiencing a LOC. Results show that with a core sector experiencing a LOC, SCORE-N 5 could continue operating safely at a reduced power of 166.6 kWth. (authors)

  17. Design of a hydraulic power take-off system for the wave energy device with an inverse pendulum

    NASA Astrophysics Data System (ADS)

    Zhang, Da-hai; Li, Wei; Zhao, Hai-tao; Bao, Jing-wei; Lin, Yong-gang

    2014-04-01

    This paper describes a dual-stroke acting hydraulic power take-off (PTO) system employed in the wave energy converter (WEC) with an inverse pendulum. The hydraulic PTO converts slow irregular reciprocating wave motions to relatively smooth, fast rotation of an electrical generator. The design of the hydraulic PTO system and its control are critical to maximize the generated power. A time domain simulation study and the laboratory experiment of the full-scale beach test are presented. The results of the simulation and laboratory experiments including their comparison at full-scale are also presented, which have validated the rationality of the design and the reliability of some key components of the prototype of the WEC with an inverse pendulum with the dual-stroke acting hydraulic PTO system.

  18. Numerical and field tests of hydraulic transients at Piva power plant

    NASA Astrophysics Data System (ADS)

    Giljen, Z.

    2014-03-01

    In 2009, a sophisticated field investigation was undertaken and later, in 2011, numerical tests were completed, on all three turbine units at the Piva hydroelectric power plant. These tests were made in order to assist in making decisions about the necessary scope of the reconstruction and modernisation of the Piva hydroelectric power plant, a plant originally constructed in the mid-1970s. More specifically, the investigation included several hydraulic conditions including both the start-up and stopping of each unit, load rejection under governor control from different initial powers, as well as emergency shut-down. Numerical results were obtained using the method of characteristics in a representation that included the full flow system and the characteristics of each associated Francis turbine. The impact of load rejection and emergency shut-down on the penstock pressure and turbine speed changes are reported and numerical and experimental results are compared, showing close agreement.

  19. Analysis of power-law self-similar solutions to the problem of hydraulic fracture crack formation

    Microsoft Academic Search

    N. N. Smirnov; V. R. Tagirova

    2007-01-01

    The problem of hydraulic fracture crack propagation in a porous medium is studied in the approximation of small crack opening\\u000a and the inertialess flow of an incompressible Newtonian hydraulic fracturing fluid inside the crack. A one-parameter family\\u000a of power-law self-similar solutions is considered in order to determine the crack width evolution, the fluid velocity in the\\u000a crack, and the seepage

  20. Modeling the performance of the piston ring-pack with consideration of non-axisymmetric characteristics of the power cylinder system in internal combustion engines

    E-print Network

    Liu, Liang, 1971-

    2005-01-01

    The performance of the piston ring-pack is directly associated with the friction, oil consumption, wear, and blow-by in internal combustion engines. Because of non-axisymmetric characteristics of the power cylinder system, ...

  1. Horizontal Steam Generator Thermal-Hydraulics at Various Steady-State Power Levels

    SciTech Connect

    Stevanovic, Vladimir D. [University of Belgrade, Kraljice Marije 16, 11000 Belgrade, Serbia and Montenegro (Yugoslavia); Stosic, Zoran V.; Kiera, Michael; Stoll, Uwe [Framatome ANP GmbH, P.O. Box 3220, 91050 Erlangen (Germany)

    2002-07-01

    Three-dimensional computer simulation and analyses of the horizontal steam generator thermal-hydraulics of the WWER 1000 nuclear power plant have been performed for 50% and 75% partial loads, 100% nominal load and 110% over-load. Presented results show water and steam mass flow rate vectors, steam void fraction spatial distribution, recirculation zones, swell level position, water mass inventory on the shell side, and other important thermal-hydraulic parameters. The simulations have been performed with the computer code 3D ANA, based on the 'two-fluid' model approach. Steam-water interface transport processes, as well as tube bundle flow resistance, energy transfer, and steam generation within tube bundles are modelled with {sup c}losure laws{sup .} Applied approach implies non-equilibrium thermal and flow conditions. The model is solved by the control volume procedure, which has been extended in order to take into account the 3D flow of liquid and gas phase. The methodology is validated by comparing numerical and experimental results of real steam generator operational conditions at various power levels of the WWER Novovoronezh, Unit 5. One-dimensional model of the horizontal steam generator has been built with the RELAP 5 standard code on the basis of the multidimensional two-phase flow structure obtained with the 3D ANA code. RELAP 5 and 3D ANA code results are compared, showing acceptable agreement. (authors)

  2. Valve Packing

    NASA Technical Reports Server (NTRS)

    1992-01-01

    "S Glass" yarn was originally developed by NASA for high temperature space and aeronautical applications. When John Crane, Inc. required material that would withstand temperatures higher than 1,200 degrees Fahrenheit, they contacted Owens-Corning, which had developed a number of applications for the material. John Crane combines the yarn with other components to make Style 287-I packing. The product can be used in chemical processing operations, nuclear power stations, petroleum products, etc. Advantages include increased service life and reduced maintenance costs.

  3. High-Order Modeling of Hydraulic Power Plant in Islanded Power Network

    Microsoft Academic Search

    Christophe Nicolet; Bob Greiveldinger; Jean Jacques Herou; Basile Kawkabani; Philippe Allenbach; Jean-Jacques Simond

    2007-01-01

    Numerical simulations of the transient operation of an islanded power network subject to load rejections are performed. The islanded power network case study consists of a 1-GW hydroelectric power plant featuring four generating units, a long penstock, and a surge tank connected to four 1.3-GW thermal power plants and passive consumers. The modeling of every network component is described and

  4. Thermal-Hydraulic Performance of Cross-Shaped Spiral Fuel in High-Power-Density BWRs

    SciTech Connect

    Conboy, Thomas; Hejzlar, Pavel [Massachusetts Institute of Technology, 77 massachusetts avenue cambridge, ma 02139-4307 (United States)

    2006-07-01

    Power up-rating of existing nuclear reactors promises to be an area of great study for years to come. One of the major approaches to efficiently increasing power density is by way of advanced fuel design, and cross-shaped spiral-fuel has shown such potential in previous studies. Our work aims to model the thermal-hydraulic consequences of filling a BWR core with these spiral-shaped pins. The helically-wound pins have a cross-section resembling a 4-petaled flower. They fill an assembly in a tight bundle, their dimensions chosen carefully such that the petals of neighboring pins contact each other at their outer-most extent in a self-supporting lattice, absent of grid spacers. Potential advantages of this design raise much optimism from a thermal-hydraulic perspective. These spiral rods possess about 40% larger surface area than traditional rods, resulting in increased cooling and a proportional reduction in average surface heat flux. The thin petal-like extensions help by lowering thermal resistance between the hot central region of the pin and the bulk coolant flow, decreasing the maximum fuel temperature by 200 deg. C according to Finite Element (COSMOS) models. However, COSMOS models also predict a potential problem area at the 'elbow' region of two adjoining petals, where heat flux peaking is twice that along the extensions. Preliminary VIPRE models, which account only for the surface area increase, predict a 22% increase in critical power. It is also anticipated that the spiral twist would provide the flowing coolant with an additional radial velocity component, and likely promote turbulence and mixing within an assembly. These factors are expected to provide further margin for increased power density, and are currently being incorporated into the VIPRE model. The reduction in pressure drop inherent in any core without grid-spacers is also expected to be significant in aiding core stability, though this has not yet been quantified. Spiral-fuel seems to be a favorable alternative to traditional pins from a thermal-hydraulic standpoint, though further study of the trends shown in this paper are required. (authors)

  5. Advanced EV/HEV battery pack testing using the ABC-150 power system

    SciTech Connect

    Gill, J. [AeroVironment, Inc., Monrovia, CA (United States)

    1997-12-01

    The ABC-150 battery test system is the first system designed for the demanding requirements of electric vehicle (EV) and hybrid electric vehicle (HEV) battery testing. With high accuracy, fast response and flexible test automation capabilities, the ABC-150 provides the most advanced set of capabilities for EV/HEV battery pack testing. These features are described and several examples of actual use are given.

  6. Constant-Pressure Hydraulic Pump

    NASA Technical Reports Server (NTRS)

    Galloway, C. W.

    1982-01-01

    Constant output pressure in gas-driven hydraulic pump would be assured in new design for gas-to-hydraulic power converter. With a force-multiplying ring attached to gas piston, expanding gas would apply constant force on hydraulic piston even though gas pressure drops. As a result, pressure of hydraulic fluid remains steady, and power output of the pump does not vary.

  7. Hydraulic turbines for electric power generation. January 1970-February 1981 (citations from the NTIS data base). Report for January 1970-February 1981. [41 citations

    SciTech Connect

    Not Available

    1981-02-01

    This bibliography covers information on studies, design, construction, and applications of hydraulic turbines used for electric power generation and water pumping. Topics include erosion, corrosion, fatigue cracking, cavitation, and runners in hydraulic turbines. (Contains 41 citations fully indexed and including a title list.)

  8. Hydraulic turbines for electric power generation. January 1970-February 1981 (citations from the Engineering Index data base). Report for January 1970-February 1981. [198 citations

    SciTech Connect

    Not Available

    1981-02-01

    This bibliography covers information on studies, design, construction, and applications of hydraulic turbines used for electric power generation and water pumping. Topics include erosion, corrosion, fatigue cracking, cavitation, and runners in hydraulic turbines. (Contains 198 citations fully indexed and including a title list.)

  9. Hydraulic turbines for electric power generation. January 1976-February 1981 (citations from the Energy Data Base). Report for January 1976-February 1981. [200 citations

    SciTech Connect

    Not Available

    1981-02-01

    This bibliography covers information on studies, design, construction, and applications of hydraulic turbines used for electric power generation and water pumping. Topics include erosion, corrosion, fatigue cracking, cavitation, and runners in hydraulic turbines. (Contains 200 citations fully indexed and including a title list.)

  10. Extending PowerPack for Profiling and Analysis of High Performance Accelerator-Based Systems

    SciTech Connect

    Li, Bo; Chang, Hung-Ching; Song, Shuaiwen; Su, Chun-Yi; Meyer, Timmy; Mooring, John; Cameron, Kirk

    2014-12-01

    Accelerators offer a substantial increase in efficiency for high-performance systems offering speedups for computational applications that leverage hardware support for highly-parallel codes. However, the power use of some accelerators exceeds 200 watts at idle which means use at exascale comes at a significant increase in power at a time when we face a power ceiling of about 20 megawatts. Despite the growing domination of accelerator-based systems in the Top500 and Green500 lists of fastest and most efficient supercomputers, there are few detailed studies comparing the power and energy use of common accelerators. In this work, we conduct detailed experimental studies of the power usage and distribution of Xeon-Phi-based systems in comparison to the NVIDIA Tesla and at SandyBridge.

  11. Research on the energy-saving potentiality of electro-hydraulic Power Steering System based on energy flow

    Microsoft Academic Search

    Zhu Renxue; Gao Lanfang; Li Xuezhi

    2010-01-01

    The development and design of new energy-saving system of electro-hydraulic power steering (EHPS) has extensive application prospect. EHPS system is analyzed by using energy flow method, system model based on energy cost is established, and relevant compute simulation is performed. Tests are carried out on the hardware-in-the-loop (HIL) bench. The results showed that system voltage supply, PWM duty cycle, pump

  12. American Recovery & Reinvestment Act: Fuel Cell Hybrid Power Packs and Hydrogen Refueling for Lift Trucks

    SciTech Connect

    Block, Gus

    2011-07-31

    HEB Grocery Company, Inc. (H-E-B) is a privately-held supermarket chain with 310 stores throughout Texas and northern Mexico. H-E-B converted 14 of its lift reach trucks to fuel cell power using Nuvera Fuel Cells’ PowerEdge™ units to verify the value proposition and environmental benefits associated with the technology. Issues associated with the increasing power requirements of the distribution center operation, along with high ambient temperature in the summer and other operating conditions (such as air quality and floor surface condition), surfaced opportunities for improving Nuvera’s PowerEdge fuel cell system design in high-throughput forklift environments. The project included on-site generation of hydrogen from a steam methane reformer, called PowerTap™ manufactured by Nuvera. The hydrogen was generated, compressed and stored in equipment located outside H-E-B’s facility, and provided to the forklifts by hydrogen dispensers located in high forklift traffic areas. The PowerEdge fuel cell units logged over 25,300 operating hours over the course of the two-year project period. The PowerTap hydrogen generator produced more than 11,100 kg of hydrogen over the same period. Hydrogen availability at the pump was 99.9%. H-E-B management has determined that fuel cell forklifts help alleviate several issues in its distribution centers, including truck operator downtime associated with battery changing, truck and battery maintenance costs, and reduction of grid electricity usage. Data collected from this initial installation demonstrated a 10% productivity improvement, which enabled H-E-B to make economic decisions on expanding the fleet of PowerEdge and PowerTap units in the fleet, which it plans to undertake upon successful demonstration of the new PowerEdge reach truck product. H-E-B has also expressed interst in other uses of hydrogen produced on site in the future, such as for APUs used in tractor trailers and refrigerated transport trucks in its fleet.

  13. Evaluation of Army engine oils in hydraulic/power-transmission-system components. Final report, August 1984-November 1985

    SciTech Connect

    Marbach, H.W.; Lestz, S.J.

    1985-11-01

    The objective of the MACI Hydraulic System and Components Program is to perform technical evaluation and assessment of commerically available qualified and fielded Army engine oils and to determine if such oils can be used as hydraulic fluids in Army commercial construction equipment and material-handling equipment. Five Army specification engine lubricants--four MIL-L-2104D (one grade 10W, one grade 30, two grade 15W-40) and one MIL-L-46167, grade 0W-20--were evaluated using four critical component performance tests used by manufacturers. Data compiled from this and previous work have shown that the limiting factors of the Army engine oils used as hydraulic and multipurpose power transmission fluids appear to be (1) wet-brake chatter noise, (2) hydraulic-pump wear problems with some piston pumps using MIL-L-46167 Arctic engine oils at temperatures hotter-than-expected Arctic conditions, and possibly (3) copper corrosion. The prime area of concern is the wet-brake chatter noise.

  14. Treatment of screened dairy manure by upflow anaerobic fixed bed reactors packed with waste tyre rubber and a combination of waste tyre rubber and zeolite: effect of the hydraulic retention time.

    PubMed

    Umaña, Oscar; Nikolaeva, Svetlana; Sánchez, Enrique; Borja, Rafael; Raposo, Francisco

    2008-10-01

    Two laboratory-scale anaerobic fixed bed reactors were evaluated while treating dairy manure at upflow mode and semicontinuous feeding. One reactor was packed with a combination of waste tyre rubber and zeolite (R1) while the other had only waste tyre rubber as a microorganism immobilization support (R2). Effluent quality improved when the hydraulic retention time (HRT) increased from 1.0 to 5.5 days. Higher COD, BOD5, total and volatile solids removal efficiencies were always achieved in the reactor R1. No clogging was observed during the operation period. Methane yield was also a function of the HRT and of the type of support used, and was 12.5% and 40% higher in reactor R1 than in R2 for HRTs of 5.5 and 1.0 days, respectively. The results obtained demonstrated that this type of reactor is capable of operating with dairy manure at a HRT 5 times lower than that used in a conventional reactor. PMID:18280149

  15. Pack Saddle

    USGS Multimedia Gallery

    This is a pack saddle used by Arnold Hague in the late 1800s. The wooden saddle has leather straps and a cinch used for the animal's comfort when carrying especially large loads. Pack saddles could be used to carry panniers or other large objects. Object ID: USGS-000014...

  16. Thermal-hydraulic analysis of cross-shaped spiral fuel in high power density BWRs

    E-print Network

    Conboy, Thomas M

    2007-01-01

    Preliminary analysis of the cross-shaped spiral (CSS) fuel assembly suggests great thermal-hydraulic upside. According to computational models, the increase in rod surface area, combined with an increase in coolant turbulence ...

  17. HYDRAULIC CONDUCTIVITY OF ESSENTIALLY SATURATED PEAT

    SciTech Connect

    Nichols, R

    2008-02-27

    The Savannah River National Laboratory measured the hydraulic conductivity of peat samples using method ASTM D4511-00. Four samples of peat were packed into 73mm diameter plastic tubes and saturated from the bottom up with water. The columns were packed with Premier ProMoss III TBK peat to a dry density of approximately 0.16 gm/cc (10 lb/ft3). One column was packed using oven dried peat and the other 3 were packed using as delivered peat. The oven dried sample was the most difficult to saturate. All of the peat samples expanded during saturation resulting in a sample length (L) that was longer than when the sample was initially packed. Table 1 contains information related to the column packing. After saturation the hydraulic conductivity test was conducted using the apparatus shown in Figure 1. Three of the samples were tested at 2 different flow conductions, 1 high and 1 low. Table 2 and Figure 2 contain the results of the hydraulic conductivity testing. Each test was run for a minimum of 40 minutes to allow the test conditions to stabilize. The hydraulic conductivity at the end of each test is reported as the hydraulic conductivity for that test. The hydraulic conductivity of the 4 peat samples is 0.0052 {+-} 0.0009 cm/sec. This result compares well with the hydraulic conductivity measured in the pilot scale peat bed after approximately 2 months of operation. The similarity in results between the dry pack sample and moist pack samples shows the moisture content at the time of packing had a minimal effect on the hydraulic conductivity. Additionally, similarity between the results shows the test is reproducible. The hydraulic conductivity results are similar to those reported by other tests of peat samples reported in the literature.

  18. Electric-hydraulic car

    SciTech Connect

    Clark, R.W.; Greene, H.

    1993-07-27

    A propulsion system is described for a vehicle having a chassis and at least one drive wheel, the propulsion system including in combination: a constant speed power source comprising an alternating current electric motor operated at a constant speed corresponding to its optimum performance; a source of energy comprising a storage battery and an inverter connected to the electric motor for operating the electric motor of the constant speed power source; a hydraulic fluid system including a main hydraulic pump coupled with the electric motor of the constant speed power source and driven thereby; at least one hydraulic drive motor coupled with the hydraulic pump for receiving fluid flow therefrom; and means for varying the fluid flow through the main hydraulic pump to vary the speed of operation of the hydraulic drive motor.

  19. Hydraulic Transport of Ice-Water Mixtures

    NASA Astrophysics Data System (ADS)

    Fujita, Toshihiko

    When an ice thermal storage system is introduced into a district cooling system,the hydraulic ice transport system must have an advantage over a conventional water transport system in saving pipe sizes and pumping powers. Referring to the literature providing direct information on the hydraulic transport of ice-water mixtures,the author comments on the following subjects : •Definitions of an ice packing factor. • The capacity of heat transported with ice-water mixtures. • District distribution system. • Flow patterns in ice-water two-phase flow in straight pipes. • General expressions for pressure losses in solid-liquid two-phase flow. • The characteristics of pressure losses in ice-water two-phase flow. •Choking phenomena in channels.

  20. Degradation of Phosphate Ester Hydraulic Fluid in Power Station Turbines Investigated by a Three-Magnet Unilateral Magnet Array

    PubMed Central

    Guo, Pan; He, Wei; García-Naranjo, Juan C.

    2014-01-01

    A three-magnet array unilateral NMR sensor with a homogeneous sensitive spot was employed for assessing aging of the turbine oils used in two different power stations. The Carr-Purcell-Meiboom-Gill (CPMG) sequence and Inversion Recovery-prepared CPMG were employed for measuring the 1H-NMR transverse and longitudinal relaxation times of turbine oils with different service status. Two signal components with different lifetimes were obtained by processing the transverse relaxation curves with a numeric program based on the Inverse Laplace Transformation. The long lifetime components of the transverse relaxation time T2eff and longitudinal relaxation time T1 were chosen to monitor the hydraulic fluid aging. The results demonstrate that an increase of the service time of the turbine oils clearly results in a decrease of T2eff,long and T1,long. This indicates that the T2eff,long and T1,long relaxation times, obtained from the unilateral magnetic resonance measurements, can be applied as indices for degradation of the hydraulic fluid in power station turbines. PMID:24736132

  1. Degradation of phosphate ester hydraulic fluid in power station turbines investigated by a three-magnet unilateral magnet array.

    PubMed

    Guo, Pan; He, Wei; García-Naranjo, Juan C

    2014-01-01

    A three-magnet array unilateral NMR sensor with a homogeneous sensitive spot was employed for assessing aging of the turbine oils used in two different power stations. The Carr-Purcell-Meiboom-Gill (CPMG) sequence and Inversion Recovery-prepared CPMG were employed for measuring the ¹H-NMR transverse and longitudinal relaxation times of turbine oils with different service status. Two signal components with different lifetimes were obtained by processing the transverse relaxation curves with a numeric program based on the Inverse Laplace Transformation. The long lifetime components of the transverse relaxation time T?eff and longitudinal relaxation time T? were chosen to monitor the hydraulic fluid aging. The results demonstrate that an increase of the service time of the turbine oils clearly results in a decrease of T?eff,long and T?,long. This indicates that the T?eff,long and T?,long relaxation times, obtained from the unilateral magnetic resonance measurements, can be applied as indices for degradation of the hydraulic fluid in power station turbines. PMID:24736132

  2. Use of electrical power for heat supply at hydraulic engineering projects

    Microsoft Academic Search

    P. M. Matko

    1971-01-01

    Conclusions  \\u000a \\u000a \\u000a \\u000a 1. \\u000a \\u000a A detailed analysis and cost estimate of the conditions of electrical and fuel supply systems for each specific case should\\u000a precede the selection of the heat supply system for hydraulic engineering projects.\\u000a \\u000a \\u000a \\u000a \\u000a 2. \\u000a \\u000a In the case of commensurable cost indices of comparable heat supply systems preference should be given to electrical heat\\u000a supply systems which technically most fully

  3. Safety properties of liquid state soft pack high power batteries with carbon-coated LiFePO 4 \\/graphite electrodes

    Microsoft Academic Search

    Yan-Bing He; Guo-Wei Ling; Zhi-Yuan Tang; Quan-Sheng Song; Quan-Hong Yang; Wu Chen; Wei Lv; Yan-Jun Su; Qiang Xu

    2010-01-01

    The carbon-coated LiFePO4 materials were synthesized, and their structure and morphology were characterized by X-ray diffraction and transmission electron\\u000a microscopy. The safety and heating mechanism of the 066094-type liquid state soft pack high power batteries with carbon-coated\\u000a LiFePO4\\/graphite electrodes under abusive conditions, such as overcharge, overdischarge, and short current were extensively investigated.\\u000a It was found that the increase in the

  4. Hydraulic turbines: hydroelectric and tidal power systems. January, 1973-September, 1981 (citations from the BHRA Fluid Engineering data base). Report for Jan 73-Sep 81

    SciTech Connect

    Not Available

    1981-09-01

    The hydrodynamics of adjustable blade hydraulic turbines are discussed as it applies to hydroelectric and tidal power generation. The adjustable blade concept is presented in terms of cavitation minimization as well as vibrational induced stresses on the blades. (Contains 91 citations fully indexed and including a title list.)

  5. ENVIRONMENTAL HYDRAULICS

    EPA Science Inventory

    The thermal, chemical, and biological quality of water in rivers, lakes, reservoirs, and near coastal areas is inseparable from a consideration of hydraulic engineering principles: therefore, the term environmental hydraulics. In this chapter we discuss the basic principles of w...

  6. Hydraulics Lectures

    NSDL National Science Digital Library

    Pytel, Jim

    This page from the WindTech TV project provides a link to lectures created by Jim Pytel for his hydraulics course at Columbia Gorge Community College. The lectures consist of live videos and screen capture style presentations and may be viewed free of charge. Clicking on the video link in the center of the page will lead users to a YouTube page with 31 lectures. Topics include hydraulics math, hydraulic safety, basic hydraulic schematics, viscosity, piston pumps, actuators, troubleshooting and more. These lectures would be extremely useful for technical and community college students taking a fundamental hydraulics course. Flash is required to view the videos.

  7. Paper Number Sizing and Optimal Operation of a Power Split Hydraulic

    E-print Network

    Li, Perry Y.

    hybrid technologies, including flywheel energy storage are rarely found in transportation vehicles is at rest or when a sufficient amount of energy is stored in the alternative energy storage. Various hybrid as alternative energy storage and electric motors and generators are used to assist the engine in power, is often

  8. Portable Hydraulic Powerpack

    NASA Technical Reports Server (NTRS)

    Anderson, L. A.; Henry, R. L.; Fedor, O. H.; Owens, L. J.

    1986-01-01

    Rechargeable hydraulic powerpack functions as lightweight, compact source of mechanical energy. Self-contained hydraulic powerpack derives energy from solid chemical charge. Combustion of charge initiated by small hammer, and revolving feeder replaces charges expended. Combustion gases cool during expansion in turbine and not too hot for release to atmosphere. Unit has applications driving wheelchairs and operating drills, winches, and other equipment in remote areas. Also replaces electric motors and internal-combustion engines as source of power in explosive atmospheres.

  9. Preliminary evaluation of the use of hydraulic air compressors in water-compensated reservoir compressed air storage power plants. [Entrainment of air bubbles by a column of downward-flowing water

    Microsoft Academic Search

    F. W. Ahrens; J. A. Berghmans

    1978-01-01

    A new air compression system for CAES applications, based on the hydraulic compressor principle, is described and evaluated. In addition to yielding a more efficient use of energy from the base power plant, due to isothermal air compression, the hydraulic air compressor does not require the conventional intercoolers and aftercooler, and it replaces the air compressors with water pumps. Using

  10. Architecture-specific packing for virtex-5 FPGAs

    Microsoft Academic Search

    Taneem Ahmed; Paul D. Kundarewich; Jason Helge Anderson; Brad L. Taylor; Rajat Aggarwal

    2008-01-01

    We consider packing in the commercial FPGA context and examine the speed, performance and power trade-offs associ- ated with packing in a state-of-the art FPGA - the Xilinx R VirtexTM-5 FPGA. Two aspects of packing are discussed: 1) packing for general logic blocks, and 2) packing for large IP blocks. Virtex-5 logic blocks contain dual-output 6-input look-up-tables (LUTs). Such LUTs

  11. Investigation of alternate power source for Space Shuttle Orbiter hydraulic system

    NASA Technical Reports Server (NTRS)

    Simon, William E.; Young, Fred M.

    1993-01-01

    This investigation consists of a short-term feasibility study to determine whether or not an alternate electrical power source would trade favorably from a performance, reliability, safety, operation, and weight standpoint in replacing the current auxiliary power unit subsystems with its attendant components (water spray boiler, hydrazine fuel and tanks, feed and vent lines, controls, etc.), operating under current flight rules. Results of this feasibility study are used to develop recommendations for the next step (e.g., to determine if such an alternate electrical power source would show an advantage given that the current operational flight mode of the system could be modified in such a way as not to constrain the operational capability and safety of the vehicle). However, this next step is not within the scope of this investigation. This study does not include a cost analysis, nor does it include investigation of the integration aspects involved in such a trade, except in a qualitative sense for the determination of concept feasibility.

  12. Analysis of Small-Scale Hydraulic Systems Jicheng Xia

    E-print Network

    Durfee, William K.

    Analysis of Small-Scale Hydraulic Systems Jicheng Xia Department of Mechanical Engineering, MN, 55455 Email: wkdurfee@umn.edu We investigated small-scale hydraulic power system using a system- mine whether the high power density advantage of hydraulic power system holds at small sizes. Hydraulic

  13. Variable-Displacement Hydraulic Drive Unit

    NASA Technical Reports Server (NTRS)

    Lang, D. J.; Linton, D. J.; Markunas, A.

    1986-01-01

    Hydraulic power controlled through multiple feedback loops. In hydraulic drive unit, power closely matched to demand, thereby saving energy. Hydraulic flow to and from motor adjusted by motor-control valve connected to wobbler. Wobbler angle determines motor-control-valve position, which in turn determines motor displacement. Concept applicable to machine tools, aircraft controls, and marine controls.

  14. Hydraulic properties of two-dimensional random fracture networks following a power law length distribution: 1. Effective connectivity

    NASA Astrophysics Data System (ADS)

    de Dreuzy, Jean-Raynald; Davy, Philippe; Bour, Olivier

    2001-08-01

    Natural fracture networks involve a very broad range of fractures of variable lengths and apertures, modeled, in general, by a power law length distribution and a lognormal aperture distribution. The objective of this two-part paper is to characterize the permeability variations as well as the relevant flow structure of two-dimensional isotropic models of fracture networks as determined by the fracture length and aperture distributions and by the other parameters of the model (such as density and scale). In this paper we study the sole influence of the fracture length distribution on permeability by assigning the same aperture to all fractures. In the following paper [de Dreuzy et al., this issue] we study the more general case of networks in which fractures have both length and aperture distributions. Theoretical and numerical studies show that the hydraulic properties of power law length fracture networks can be classified into three types of simplified model. If a power law length distribution n (l) ˜ l-a is used in the network design, the classical percolation model based on a population of small fractures is applicable for a power law exponent a higher than 3. For a lower than 2, on the contrary, the applicable model is the one made up of the largest fractures of the network. Between these two limits, i.e., for a in the range 2-3, neither of the previous simplified models can be applied so that a simplified two-scale structure is proposed. For this latter model the crossover scale is the classical correlation length, defined in the percolation theory, above which networks can be homogenized and below which networks have a multipath, multisegment structure. Moreover, the determination of the effective fracture length range, within which fractures significantly contribute to flow, corroborates the relevance of the previous models and clarifies their geometrical characteristics. Finally, whatever the exponent a, the sole significant scale effect is a decrease of the equivalent permeability for networks below or at percolation threshold.

  15. Well packing system

    Microsoft Academic Search

    Drnevich

    1990-01-01

    This patent describes a packing structure and method of packing which can be used in the wellbore of injection wells for the recovery of heavy oils, shale oils, and tars, and in well shafts for in-situ coal gasification. The packing can also be used in the wellbore of gas and light oil production wells. The packing is used to provide

  16. Tribology of hydraulic pumps

    SciTech Connect

    Yamaguchi, A. [Yokohama National Univ. (Japan). Dept. of Mechanical Engineering and Materials Science

    1997-12-31

    To obtain much higher performance than that of alternative power transmission systems, hydraulic systems have been continuously evolving to use high-pressure. Adoption of positive displacement pumps and motors is based on this reason. Therefore, tribology is a key terminology for hydraulic pumps and motors to obtain excellent performance and durability. In this paper the following topics are investigated: (1) the special feature of tribology of hydraulic pumps and motors; (2) indication of the important bearing/sealing parts in piston pumps and effects of the frictional force and leakage flow to performance; (3) the methods to break through the tribological limitation of hydraulic equipment; and (4) optimum design of the bearing/sealing parts used in the fluid to mixed lubrication regions.

  17. Hydraulics. FOS: Fundamentals of Service.

    ERIC Educational Resources Information Center

    John Deere Co., Moline, IL.

    This manual on hydraulics is one of a series of power mechanics texts and visual aids for training in the servicing of agricultural and industrial machinery. Focus is on oil hydraulics. Materials provide basic information and illustrations for use by vocational students and teachers as well as shop servicemen and laymen. The twelve chapters focus…

  18. Extended Kalman filtering for battery management systems of LiPB-based HEV battery packs

    Microsoft Academic Search

    Gregory L. Plett

    2004-01-01

    Battery management systems in hybrid electric vehicle battery packs must estimate values descriptive of the pack’s present operating condition. These include: battery state of charge, power fade, capacity fade, and instantaneous available power. The estimation mechanism must adapt to changing cell characteristics as cells age and therefore provide accurate estimates over the lifetime of the pack.In a series of three

  19. DESIGN OF INTELLIGENT HYDRAULIC EXCAVATOR CONTROL SYSTEM BASED ON

    E-print Network

    DESIGN OF INTELLIGENT HYDRAULIC EXCAVATOR CONTROL SYSTEM BASED ON PID METHOD Jun Zhang 1 the constant power design method and set 85%~90% of engine power as the hydraulic system adoption power the power matching between engine and pump through engine speed. Based on negative flux hydraulic system

  20. Lock for hydraulic actuators

    NASA Technical Reports Server (NTRS)

    Wood, R. H.

    1981-01-01

    Two clamps hold rod in fixed extension from cylinder even when power is off, converting actuator into stiff structural member. Locked actuator is useful as mechanical support or linkage or as fail-safe device in case of loss of hydraulic pressure. Potential applications include manufacturing processes and specialized handling and holding devices.

  1. Packing Patterns into Words

    Microsoft Academic Search

    Alexander Burstein; Peter Hästö; Toufik Mansour

    2002-01-01

    Abstract In this article we generalize packing density problems from permutations to patterns with repeated letters and generalized patterns We are able to find the packing density for some classes of patterns and several other short patterns

  2. AUTOMOTIVE DIESEL MAINTENANCE 2. UNIT III, AUTOMATIC TRANSMISSIONS--HYDRAULICS (PART I).

    ERIC Educational Resources Information Center

    Human Engineering Inst., Cleveland, OH.

    THIS MODULE OF A 25-MODULE COURSE IS DESIGNED TO INTRODUCE BASIC HYDRAULIC PRINCIPLES AND PROVIDE AN UNDERSTANDING OF HYDRAULIC TRANSMISSIONS USED IN DIESEL POWERED VEHICLES. TOPICS ARE WHY USE HYDRAULICS, REVIEWING BASIC PHYSICS LAWS IN RELATION TO HYDRAULICS, UNDERSTANDING THE HYDRAULIC SYSTEM, AND DEVELOPING A BASIC HYDRAULIC SYSTEM. THE MODULE…

  3. PERFORMANCE OF AN AERIAL VARIABLE-RATE APPLICATION SYSTEM WITH A HYDRAULICALLY POWERED CHEMICAL PUMP AND SPRAY VALVE

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The performance was evaluated for a variable-rate system that consisted of a SATLOC M3 with AirTrac software with WAAS corrected DGPS (5 Hz position update) and an AutoCal II automatic flow controller. This system was installed on an Air Tractor 402B equipped with an auxiliary hydraulic package tha...

  4. On Discrete Hyperbox Packing 

    E-print Network

    Li, Xiafeng

    2010-01-14

    Bin packing is a very important and popular research area in the computer science field. Past work showed many good and real-world packing algorithms. How- ever, due to the complexity of the problem in multiple-dimensional bin packing, also called...

  5. Keeping hydraulic fluid clean

    SciTech Connect

    Downs, D.C. [Vickers, Inc., Maumee, OH (United States)

    1997-03-01

    Overall, fluid power is one of the most reliable and repeatable forms of motion control. However, failures do occur. Recent research has found that the root cause of many hydraulic component and system failures is fluid contamination and inadequate contamination control practices. Preventing unplanned downtime through systemic contamination control and proactive or predictive maintenance is an effective strategy that significantly reduces problems. Understanding the principles involved assist the plant engineer, machine operators, and maintenance personnel in economically achieving maximum hydraulic system life and minimum downtime. The paper discusses the sources of contamination, contamination damage, systematic contamination control, filters, and filter location.

  6. Servo Hydraulic and Pneumatic Drive

    Microsoft Academic Search

    Kok Kiong Tan; Andi Sudjana Putra

    \\u000a Among the various drives available, the hydraulic drive ranks at the forefront in terms of application history. The history\\u000a of hydraulic power dated to the beginning of civilization, where artefacts show the applications of water turbines in power\\u000a generation (Wikander, Handbook of Ancient Water Technology: Technology and Change in History, Brill, Leiden, 2000). However, more significant progress in this field

  7. Random sphere packing lattices

    NASA Astrophysics Data System (ADS)

    Kallus, Yoav

    2015-03-01

    Bravais lattices have always been an important special case of the high-dimensional sphere packing problem, but from the statistical mechanics and random packing perspectives, they have not been studied much until recently. I will discuss the statistical mechanical phenomena exhibited by a system of one sphere under periodic boundary conditions, where the only degrees of freedom are the unit cell parameters. Equilibrium behavior includes a ``crystallization'' transition, but most of the interest comes from studying non-equilibrium behavior: glass transition, random packing, and hysteresis. The random-packed lattices exhibit surprising properties, including a density remarkably higher than amorphous random packing and a quasicontact divergence.

  8. Hydraulic line pressure control system for an infinitely variable transmission

    Microsoft Academic Search

    1987-01-01

    An improved control system is described for an infinitely variable transmission for transmitting the power of an internal combustion engine mounted on a vehicle. The transmission comprises: a primary pulley having a hydraulically shiftable disc and a hydraulic cylinder for shifting the disc, a secondary pulley having a hydraulically shiftable disc and a hydraulic cylinder for operating the disc, a

  9. Hydraulic Conductivity Measurements Barrow 2014

    DOE Data Explorer

    Katie McKnight; Tim Kneafsey; Craig Ulrich; Jil Geller

    Six individual ice cores were collected from Barrow Environmental Observatory in Barrow, Alaska, in May of 2013 as part of the Next Generation Ecosystem Experiment (NGEE). Each core was drilled from a different location at varying depths. A few days after drilling, the cores were stored in coolers packed with dry ice and flown to Lawrence Berkeley National Laboratory (LBNL) in Berkeley, CA. 3-dimensional images of the cores were constructed using a medical X-ray computed tomography (CT) scanner at 120kV. Hydraulic conductivity samples were extracted from these cores at LBNL Richmond Field Station in Richmond, CA, in February 2014 by cutting 5 to 8 inch segments using a chop saw. Samples were packed individually and stored at freezing temperatures to minimize any changes in structure or loss of ice content prior to analysis. Hydraulic conductivity was determined through falling head tests using a permeameter [ELE International, Model #: K-770B]. After approximately 12 hours of thaw, initial falling head tests were performed. Two to four measurements were collected on each sample and collection stopped when the applied head load exceeded 25% change from the original load. Analyses were performed between 2 to 3 times for each sample. The final hydraulic conductivity calculations were computed using methodology of Das et al., 1985.

  10. Hydraulic flywheel

    SciTech Connect

    Maxwell, T.J.

    1982-06-22

    A pair of separable sections forming a hollow structure are coupled to a rotatable shaft. Controlled quantities of hydraulic fluid are introduced into the hollow structure through a passageway within the shaft. One of the sections is selectively slidable along the shaft, for release of fluid from within the structure.

  11. Hydraulic plant

    Microsoft Academic Search

    1983-01-01

    The plant described resolves the problem of recovering the energy generated by heat engines under test, acceptance trials or experimental tests by the generation of alternating electrical current for which the alternator is always connected to the supply network even in the absence of mechanical energy produced by said engines under test, there being provided hydraulic pumping dynamometric units which

  12. Leaf Pack Network

    NSDL National Science Digital Library

    The Leaf Pack Network (LPN) is a network of teachers and students investigating their local stream ecosystems by participating in the leaf pack experiment, which involves creating an artificial leaf pack (dry leaves in a mesh bag), immersing it in a stream for 3-4 weeks, and examining it for signs of aquatic insects as indicators of stream health. Participating classrooms share their data through the internet. This activity highlights the connection between streamside forests and the ecology of rivers and streams.

  13. Simultaneous hydraulic fracturing

    Microsoft Academic Search

    Uhri

    1989-01-01

    A process is described for simultaneous hydraulic fracturing of a hydrocarbonaceous fluid-bearing formation comprising: (a) determining a hydraulic pressure necessary to fracture the formation from at least two wells which penetrate the formation; (b) injecting a hydraulic fracturing fluid into both wells under the determined hydraulic pressure; and (c) applying simultaneously the determined hydraulic pressure to the hydraulic fluid contained

  14. Characteristics of effective industrial packings for evaporative cooling of circulating water in cooling towers

    Microsoft Academic Search

    A. M. Kagan; A. S. Pushnov; M. G. Berengarten; A. S. Ryabushenko; V. I. Shishov

    2009-01-01

    Results are presented for comparative tests of the aerothermal characteristics of basic types of regular packings on a test\\u000a bench developed by the Vedeneev All-Russia Research Institute of Hydraulic Engineering. These packings are widely used in\\u000a draft sections and similar cooling towers employed in the chemical and other branches of industry. It is demonstrated that\\u000a the drop-film type of packing

  15. Design, modeling, fabrication and testing of a piezoelectric microvalve for high pressure, high frequency hydraulic applications

    E-print Network

    Roberts, David C. (David Christopher)

    2002-01-01

    A piezoelectrically-driven hydraulic amplification microvalve for use in high specific power hydraulic pumping applications was designed, fabricated, and experimentally characterized. High frequency, high force actuation ...

  16. Hydraulic Arm Challenge

    NSDL National Science Digital Library

    Center for Engineering Educational Outreach,

    Students design and build a mechanical arm that lifts and moves an empty 12-ounce soda can using hydraulics for power. Small design teams (1-2 students each) design and build a single axis for use in the completed mechanical arm. One team designs and builds the grasping hand, another team the lifting arm, and a third team the rotation base. The three groups must work to communicate effectively through written and verbal communication and sketches.

  17. Electric versus hydraulics versus pneumatics

    SciTech Connect

    Not Available

    1985-01-01

    This book presents a collection of papers from a conference which considered the advantages and disadvantages of electric, hydraulic and pneumatic drives and actuators. The volume follows on the success of the 1983 conference on electric and hydraulic drives. Topics considered include fork lift trucks - an ideal application for regenerative transmissions; a hybrid-electric power system with hydrostatic transmission; electrics and hydraulics on roadheader machinery; hydraulic, electrical, pneumatic control - which way to go. an electrically-powered servo to drive the two axes of a missile launching platform - pros and cons when compared with the traditional hydraulic solution; the encapsulation of a novel intrinsically safe displacement transducer; mobile cryogenic pumping systems; automation of a wood-turning machine, hydraulic or electric. The choice of a servo motor for a specific application; developments in the design and control of pneumatic linear actuators; compressed air purification for instrumentation in the high technology industries; trends in prime mover choice for powered hand tools; and choosing the drive system for the right application.

  18. Experimental investigations of thermal-hydraulic processes arising during operation of the passive safety systems used in new projects of nuclear power plants equipped with VVER reactors

    NASA Astrophysics Data System (ADS)

    Morozov, A. V.; Remizov, O. V.; Kalyakin, D. S.

    2014-05-01

    The results obtained from experimental investigations into thermal-hydraulic processes that take place during operation of the passive safety systems used in new-generation reactor plants constructed on the basis of VVER technology are presented. The experiments were carried out on the model rigs available at the Leipunskii Institute for Physics and Power Engineering. The processes through which interaction occurs between the opposite flows of saturated steam and cold water moving in the vertical steam line of the additional system for passively flooding the core from the second-stage hydro accumulators are studied. The specific features pertinent to undeveloped boiling of liquid on a single horizontal tube heated by steam and steam-gas mixture that is typical for of the condensing operating mode of a VVER reactor steam generator are investigated.

  19. Estimation of the hydraulic conductivity of a two-dimensional fracture network using effective medium theory and power-law averaging

    NASA Astrophysics Data System (ADS)

    Zimmerman, R. W.; Leung, C. T.

    2009-12-01

    Most oil and gas reservoirs, as well as most potential sites for nuclear waste disposal, are naturally fractured. In these sites, the network of fractures will provide the main path for fluid to flow through the rock mass. In many cases, the fracture density is so high as to make it impractical to model it with a discrete fracture network (DFN) approach. For such rock masses, it would be useful to have recourse to analytical, or semi-analytical, methods to estimate the macroscopic hydraulic conductivity of the fracture network. We have investigated single-phase fluid flow through generated stochastically two-dimensional fracture networks. The centers and orientations of the fractures are uniformly distributed, whereas their lengths follow a lognormal distribution. The aperture of each fracture is correlated with its length, either through direct proportionality, or through a nonlinear relationship. The discrete fracture network flow and transport simulator NAPSAC, developed by Serco (Didcot, UK), is used to establish the “true” macroscopic hydraulic conductivity of the network. We then attempt to match this value by starting with the individual fracture conductances, and using various upscaling methods. Kirkpatrick’s effective medium approximation, which works well for pore networks on a core scale, generally underestimates the conductivity of the fracture networks. We attribute this to the fact that the conductances of individual fracture segments (between adjacent intersections with other fractures) are correlated with each other, whereas Kirkpatrick’s approximation assumes no correlation. The power-law averaging approach proposed by Desbarats for porous media is able to match the numerical value, using power-law exponents that generally lie between 0 (geometric mean) and 1 (harmonic mean). The appropriate exponent can be correlated with statistical parameters that characterize the fracture density.

  20. Graphitic packing removal tool

    DOEpatents

    Meyers, Kurt Edward (Avella, PA); Kolsun, George J. (Pittsburgh, PA)

    1997-01-01

    Graphitic packing removal tools for removal of the seal rings in one piece. he packing removal tool has a cylindrical base ring the same size as the packing ring with a surface finish, perforations, knurling or threads for adhesion to the seal ring. Elongated leg shanks are mounted axially along the circumferential center. A slit or slits permit insertion around shafts. A removal tool follower stabilizes the upper portion of the legs to allow a spanner wrench to be used for insertion and removal.

  1. Graphitic packing removal tool

    SciTech Connect

    Meyers, K.E.; Kolsun, G.J.

    1996-12-31

    Graphitic packing removal tools are described for removal of the seal rings in one piece from valves and pumps. The packing removal tool has a cylindrical base ring the same size as the packing ring with a surface finish, perforations, knurling or threads for adhesion to the seal ring. Elongated leg shanks are mounted axially along the circumferential center. A slit or slits permit insertion around shafts. A removal tool follower stabilizes the upper portion of the legs to allow a spanner wrench to be used for insertion and removal.

  2. Hydraulic wind energy conversion system

    SciTech Connect

    Not Available

    1981-07-01

    The purpose of this research was to design, build and test a hydraulic wind energy system. This design used a three bladed turbine, which drove a hydraulic pump. The energy is transmitted from the pump through a long hose and into a hydraulic motor, where the energy is used. This wind system was built and tested during the winter of 1980-1981. The power train included a five meter, three bladed wind turbine, a 9.8:1 ratio gearbox, a 1.44 cubic inch displacement pump with a small supercharge gear pump attached. The hydraulic fluid was pumped through a 70', 3/4'' I-D-high pressure flexhose, then through a volume control valve and into a 1.44 cubic inch displacement motor. The fluid was returned through a 70', 1'' I-D-flexhose.

  3. Low energy consumption hydraulic techniques

    NASA Astrophysics Data System (ADS)

    Greene, J. B.; Jeffrey, J. R.; Lohe, S. N.; Pehowski, S. E.; Pierce, N. J.

    1988-08-01

    This report documents the efforts to develop and test low energy consumption hydraulic techniques. Included is a discussion of the efforts to select and analyze a baseline hydraulic system (Phase 1) and conduct trade studies on various candidate design approaches which could reduce weight and power consumption (Phase 2). In addition, the report discusses the development of a test plan (Phase 3) and the results of an endurance test (Phase 4). This program was directed at 8000 psi hydraulic system technology using a nonflammable hydraulic fluid chlorotrifluoroethylene (CTFE) although the concepts developed could be applied to any fluid at any system pressure. The concepts selected for test were variable system pressure, flow augmentation with load recovery valves and overlapped main valves.

  4. Development, setup and testing of a dynamic hydraulic fracture conductivity apparatus 

    E-print Network

    Pongthunya, Potcharaporn

    2009-06-02

    One of the most critical parameters in the success of a hydraulic fracturing treatment is to have sufficiently high fracture conductivity. Unbroken polymers can cause permeability impairment in the proppant pack and/or in the matrix along...

  5. The impact of gravity segregation on multiphase non-Darcy flow in hydraulically fractured gas wells 

    E-print Network

    Dickins, Mark Ian

    2008-10-10

    Multiphase and non-Darcy flow effects in hydraulically fractured gas wells reduce effective fracture conductivity. Typical proppant pack laboratory experiments are oriented in such a way such that phase segregation is not possible, which results...

  6. Development, setup and testing of a dynamic hydraulic fracture conductivity apparatus

    E-print Network

    Pongthunya, Potcharaporn

    2009-06-02

    One of the most critical parameters in the success of a hydraulic fracturing treatment is to have sufficiently high fracture conductivity. Unbroken polymers can cause permeability impairment in the proppant pack and/or in the matrix along...

  7. The purpose of this pack This pack presents the Forestry

    E-print Network

    The purpose of this pack This pack presents the Forestry Commission's key messages on climate change. It draws together the information available from the Forestry Commission, Forest Research in tackling climate change. Who is this pack aimed at? The pack is primarily aimed at Forestry Commission

  8. Nasal packing and stenting

    PubMed Central

    Weber, Rainer K.

    2011-01-01

    Nasal packs are indispensable in ENT practice. This study reviews current indications, effectiveness and risks of nasal packs and stents. In endoscopic surgery, nasal packs should always have smooth surfaces to minimize mucosal damage, improve wound healing and increase patient comfort. Functional endoscopic endonasal sinus surgery allows the use of modern nasal packs, since pressure is no longer required. So called hemostatic/resorbable materials are a first step in this direction. However, they may lead to adhesions and foreign body reactions in mucosal membranes. Simple occlusion is an effective method for creating a moist milieu for improved wound healing and avoiding dryness. Stenting of the frontal sinus is recommended if surgery fails to produce a wide, physiologically shaped drainage path that is sufficiently covered by intact tissue. PMID:22073095

  9. Hydraulic clutch

    SciTech Connect

    Ohkubo, M.

    1986-11-18

    This patent describes a hydraulic clutch comprising: an input member, an output member rotatable coaxially with the input member; friction means provided between the input and output members for selectively engaging and disengaging the members from each other; an annular hydraulic piston slidably mounted on one of the members for selectively actuating the friction means, and having an axially directed back face and an annular coned disc spring interposed between the piston and the friction means, the spring having a radially inner peripheral end, a radially outer peripheral end, and a piston-contacting portion radially intermediate inner and outer peripheral ends. The inner peripheral end is supported on the piston-mounting member at a position apart from the piston, the spring having a cross-sectional shape such that the piston contacting portion is axially closest to the back face of the piston relative to both the inner peripheral end and the outer peripheral end. The piston-contacting portion move gradually radially outwardly with increasing contact pressure by the piston.

  10. Sequential Vector Packing

    Microsoft Academic Search

    Mark Cieliebak; Alexander Hall; Riko Jacob; Marc Nunkesser

    2007-01-01

    We introduce a novel variant of the well known d-dimensional bin (or vector) packing problem. Given a sequence of non-negative d-dimensional vectors, the goal is to pack these into as few bins as possible. In the classical problem the bin size vector is given and the sequence can be partitioned arbi- trarily. We study a variation where the vectors have

  11. Hydraulic well pump

    SciTech Connect

    Dollison, W.W.

    1986-02-25

    This patent describes a system for operating a sucker rod string connected with a well pump. This pump consists of: a double-acting fluid cylinder having opposing power ends; means for connecting the cylinder with the sucker rod string for raising and lowering the string to operate the pump; means for supplying pressurized fluid alternately to the cylinder ends including a direction control movable between extend and retract conditions to extend and retract the cylinder; drive means for shifting the direction control; control means for operating the drive means responsive to the extend and retract movements of the cylinder; including limit valves positioned to simulate the hydraulic cylinder extend and retract stroke end locations, the limit valves being movably mounted for changing the location of each limit valve and the distance between the limit valves for selectively adjusting the length of the strokes of the hydraulic cylinder and the end limit of the extend and retract strokes of the cylinder. A cam operator is for opening and closing each of the limit valves at the end locations and means connecting the cam operator means with the hydraulic cylinder. Cable is reeved over the movable and fixed sheave means and secured along the second end thereof at a fixed location; and means for applying a fluid counterbalancing force into the cylinder for offsetting the combined weights of the sucker rods string, a production fluid column in a well core above the pump, and movable surface equipment supported on the cylinder.

  12. Hydraulic well pump

    SciTech Connect

    Dollison, W.W.

    1987-09-08

    This patent describes a system for operating a sucker rod string connected with a well pump comprising: a double-acting fluid cylinder having opposing power ends; means for connecting the cylinder with the sucker rod string for raising and lowering the string to operate the pump; hydraulic pump means for supplying pressurized fluid alternately to the cylinder ends including a direction control movable between extend and retract conditions to extend and retract the cylinder; drive means for shifting the direction control; control means for operating the drive means responsive to the extend and retract movements of the cylinder; and means for applying a fluid counterbalancing force into the cylinder for offsetting the combined weights of the sucker rod string. A production fluid column in a well bore above the pump, and movable surface equipment supported on the cylinder include an accumulator connected with the hydraulic pump means and the direction control for supercharging the intake of the pump during the extend movement of the cylinder and for applying an opposing hydraulic force to the cylinder during the retract movement.

  13. Extended Kalman filtering for battery management systems of LiPB-based HEV battery packs

    Microsoft Academic Search

    Gregory L. Plett

    2004-01-01

    Battery management systems in hybrid-electric-vehicle battery packs must estimate values descriptive of the pack’s present operating condition. These include: battery state-of-charge, power fade, capacity fade, and instantaneous available power. The estimation mechanism must adapt to changing cell characteristics as cells age and therefore provide accurate estimates over the lifetime of the pack.In a series of three papers, we propose methods,

  14. Extended Kalman filtering for battery management systems of LiPB-based HEV battery packs

    Microsoft Academic Search

    Gregory L. Plett

    2004-01-01

    Battery management systems (BMS) in hybrid-electric-vehicle (HEV) battery packs must estimate values descriptive of the pack’s present operating condition. These include: battery state of charge, power fade, capacity fade, and instantaneous available power. The estimation mechanism must adapt to changing cell characteristics as cells age and therefore provide accurate estimates over the lifetime of the pack.In a series of three

  15. Hydraulic oil well pumping apparatus

    SciTech Connect

    McDuffie, T.F.

    1983-09-27

    The preferred embodiment is directed to an oil well pumping apparatus incorporating a walking beam having a horsehead at one end which connects to the sucker rods in the oil well. The opposite end of the walking beam is supported on a fixed pivot. A hydraulic and pneumatic combination unit connects from a supporting platform to a central point on the beam to raise and lower the beam. The improved apparatus utilizes air pressure to balance the static load on the apparatus and dynamically strokes the sucker rod string by imparting a reciprocating motion through hydraulic power applied at a specified rate to raise and lower the walking beam. A pump and motor system for a closed hydraulic loop is included. Alternate preferred embodiments are disclosed. In one form, a lubricating system is incorporated. First and second alternate forms of pickoff apparatus which powers the pneumatically balanced pumping apparatus is also included.

  16. An Intelligent Combined Method Based on Power Spectral Density, Decision Trees and Fuzzy Logic for Hydraulic Pumps Fault Diagnosis

    Microsoft Academic Search

    Kaveh Mollazade; Hojat Ahmadi; Mahmoud Omid; Reza Alimardani

    2008-01-01

    Recently, the issue of machine condition monitoring and fault diagnosis as a part of maintenance system became global due to the potential advantages to be gained from reduced maintenance costs, improved productivity and increased machine availability. The aim of this work is to investigate the effectiveness of a new fault diagnosis method based on power spectral density (PSD) of vibration

  17. Pessimal shapes for packing

    NASA Astrophysics Data System (ADS)

    Kallus, Yoav

    2014-03-01

    The question of which convex shapes leave the most empty space in their densest packing is the subject of Reinhardt's conjecture in two dimensions and Ulam's conjecture in three dimensions. Such conjectures about pessimal packing shapes have proven notoriously difficult to make progress on. I show that the regular heptagon is a local pessimum among all convex shapes, and that the 3D ball is a local pessimum among origin-symmetric shapes. Any shape sufficiently close in the space of shapes to these local pessima can be packed at a greater efficiency than they. In two dimensions and in dimensions above three, the ball is not a local pessimum, so the situation in 3D is unusual and intriguing. I will discuss what conditions conspire to make the 3D ball a local pessimum and whether we can prove that it is also a global pessimum.

  18. Hydraulic controls of summer Arctic pack ice albedo

    Microsoft Academic Search

    H. Eicken; T. C. Grenfell; D. K. Perovich; J. A. Richter-Menge; K. Frey

    2004-01-01

    Linkages between albedo, surface morphology, melt pond distribution, and properties of first-year and multiyear sea ice have been studied at two field sites in the North American Arctic between 1998 and 2001. It is shown that summer sea-ice albedo depends critically on surface melt-pond hydrology, controlled by melt rate, ice permeability, and topography. Remarkable short-term and interannual variability in pond

  19. 46 CFR 58.30-10 - Hydraulic fluid.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...2010-10-01 2010-10-01 false Hydraulic fluid. 58.30-10 Section 58...and Control Systems § 58.30-10 Hydraulic fluid. (a) The requirements...inspection. (b) The fluid used in hydraulic power transmission systems shall...

  20. Composite hydraulic system

    SciTech Connect

    Williamson, W.A.

    1987-03-17

    A composite hydraulic system is described for a work vehicle having an implement hydraulic circuit and a steering hydraulic circuit comprising a first pump which supplies the implement hydraulic circuit primarily, a second pump which supplies the steering hydraulic circuit primarily, a third pump which is operable also as a motor and which transfers hydraulic fluid between the implement and the steering hydraulic circuits, an engine which operates the three pumps simultaneously, and servo system means whereby the third pump under at least one condition of operation operates as a motor to provide regeneration.

  1. Study of hydraulic transients in hydropower plants through simulation of nonlinear model of penstock and hydraulic turbine model

    Microsoft Academic Search

    N. Barbieri; A. H. M. Santos

    1999-01-01

    Study of hydraulic transients in hydropower plants specifically in hydraulic turbine units, with penstock, spiral case and draft tube-is necessary due to power and frequency oscillations which normally occur in generator units, mainly during load rejections. In turn, this causes large pressure and subpressure oscillations in turbine hydraulic systems and must be evaluated to avoid mechanical failures. In this context,

  2. Hydraulic pump

    SciTech Connect

    Polak, P.R.; Jantzen, D.E.

    1984-05-15

    This invention relates to an improved pump jack characterized by a hollow piston rod which telescopes down over the sucker rod to which it is clamped for reciprocating motion. The cylinder, in turn, is fastened in fixed position directly to the upper exposed end of the well casing. As fluid is introduced into the lower end of the cylinder it raises the piston into engagement with a pushrod housed in the upper cylinder head that lifts switch-actuating means associated therewith into a position operative to actuate a switch located adjacent thereto thereby causing the latter to change state and actuate a multi-function solenoid valve so as to cut off fluid flow to the cylinder. As gravity lowers the sucker rod and piston exhausting the hydraulic fluid therebeneath, an adjustable stop engages the pushrod from above so as to return it together with the switch-actuating means associated therewith to their original positions thereby resetting the switch to complete the operating cycle.

  3. Knapsack packing networks.

    PubMed

    Hellstrom, B J; Kanal, L N

    1992-01-01

    A knapsack packing neural network of 4n units with both low-order and conjunctive asymmetric synapses is derived from a non-Hamiltonian energy function. Parallel simulations of randomly generated problems of size n in {5, 10, 20} are used to compare network solutions with those of simple greedy fast parallel enumerative algorithms. PMID:18276431

  4. Nutrition Action Pack.

    ERIC Educational Resources Information Center

    Sockut, Joanne; Stumpe, Stephanie

    One of five McDonald's Action Packs, these instructional materials integrate elementary school-level nutrition education into other disciplines--biology, sociology, physiology, mathematics, and art. Contents include four units consisting of twelve activities. Unit 1, Why You Need Food, is a self-examination of what is needed for growth, health,…

  5. DIY Fraction Pack.

    ERIC Educational Resources Information Center

    Graham, Alan; Graham, Louise

    2003-01-01

    Describes a very successful attempt to teach fractions to year 5 pupils based on pupils making their own fraction pack. Children decided for themselves how to make the fractional slices used in the activity using colored cardboard sheets and templates of a paper circle consisting of 24 equal slices. (Author/NB)

  6. Optimization of blended battery packs

    E-print Network

    Erb, Dylan C. (Dylan Charles)

    2013-01-01

    This thesis reviews the traditional battery pack design process for hybrid and electric vehicles, and presents a dynamic programming (DP) based algorithm that eases the process of cell selection and pack design, especially ...

  7. Industrial investigations of a final gas cooler with plane-parallel packing

    SciTech Connect

    Gulyaev, V.M.; Sidogin, V.P.

    1983-01-01

    The volume of coke oven gas to be refined is continually increasing. Present equipment in coking plants cannot provide further growth in capacity, since when the gas phase velocity is increased there is a significant decrease in efficiency and an increase in the hydraulic resistance. Equipment with plane-parallel packing contain significant reserves for improvement of the process. This paper describes the performance testing of a final gas cooler with plane-parallel packing and a tube irrigation device which have proved highly reliable and efficient, with low hydraulic resistance, in a coking plant in USSR. 5 references, 2 figures, 2 tables.

  8. Prepacking perforations improves gravel packs

    SciTech Connect

    Hall, B.E.; Pace, J.R. (Western Co., The Woodlands, TX (US))

    1990-05-21

    Productivity can be increased by prepacking perforations with gravel before a major gravel pack is pumped. The main gravel-pack treatment follows immediately after the prepack. This procedure can increase perforation permeability due to a more complete gravel fill of the perforation. The gravel pack prevents perforations from collapsing or filling with formation sand.

  9. Packed Bed Combustion: An Overview

    E-print Network

    Hallett, William L.H.

    Packed Bed Combustion: An Overview William Hallett Dept. of Mechanical Engineering Université d'Ottawa - University of Ottawa #12;Packed Bed Combustion - University of Ottawa - CICS 2005 Introduction air fuel feedproducts xbed grate Packed Bed Combustion: fairly large particles of solid fuel on a grate, air supplied

  10. 7 CFR 51.310 - Packing requirements.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...United States Standards for Grades of Apples Packing Requirements § 51.310 Packing requirements. (a) Apples tray packed or cell packed in cartons...3 2 “Fairly tight” means that apples are of the proper size for...

  11. 7 CFR 51.310 - Packing requirements.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...United States Standards for Grades of Apples Packing Requirements § 51.310 Packing requirements. (a) Apples tray packed or cell packed in cartons...3 2 “Fairly tight” means that apples are of the proper size for...

  12. 7 CFR 51.310 - Packing requirements.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...United States Standards for Grades of Apples Packing Requirements § 51.310 Packing requirements. (a) Apples tray packed or cell packed in cartons...3 2 “Fairly tight” means that apples are of the proper size for...

  13. 7 CFR 51.310 - Packing requirements.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...United States Standards for Grades of Apples Packing Requirements § 51.310 Packing requirements. (a) Apples tray packed or cell packed in cartons...3 2 “Fairly tight” means that apples are of the proper size for...

  14. 7 CFR 51.310 - Packing requirements.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...United States Standards for Grades of Apples Packing Requirements § 51.310 Packing requirements. (a) Apples tray packed or cell packed in cartons...3 2 “Fairly tight” means that apples are of the proper size for...

  15. Selfish Bin Packing

    Microsoft Academic Search

    Leah Epstein; Elena Kleiman

    2008-01-01

    Following recent interest in the study of computer science problems in a game theoretic setting, we consider the well known\\u000a bin packing problem where the items are controlled by selfish agents. Each agent is charged with a cost according to the fraction\\u000a of the used bin space its item requires. That is, the cost of the bin is split among

  16. Selfish Bin Packing

    Microsoft Academic Search

    Leah Epstein; Elena Kleiman

    2011-01-01

    Following recent interest in the study of computer science problems in a game theoretic setting, we consider the well known\\u000a bin packing problem where the items are controlled by selfish agents. Each agent is charged with a cost according to the fraction\\u000a of the used bin space its item requires. That is, the cost of the bin is split among

  17. Hydraulic well pumping apparatus

    SciTech Connect

    Wright, C.P.

    1987-03-03

    This patent describes a hydraulic powered well pumping apparatus for operation of a sucker rod well pump in a well borehole, the apparatus comprising: (a) an elongate polished rod having upper and lower ends, the rod being aligned above and adapted to connect to a string of sucker rods in a well borehole therebelow; (b) an adjustably positioned sleeve means aligned above and enclosing a portion of the polished rod and having a shorter length than the polished rod to enable the polished rod to extend above the sleeve means and below the sleeve means for connection to the string of sucker rods in the well borehole; (c) an axially hollow upstanding cylinder slideably receiving the sleeve means therethrough and enclosing a piston therein, the piston being: (1) moved on admitting hydraulic oil to the cylinder, and (2) joined to the sleeve means for moving the sleeve means and thereby moving the polished rod; (d) means for mounting the upstanding cylinder directly aligned with and above a casing at the top of a well adapted to have a sucker rod string positioned therein; (e) means for adjusting the stroke length imparted to the sucker rod string between minimum and maximum stroke lengths; and (f) means for adjusting the location of the sleeve means relative to the polished rod to vary the relative length of polished rod below the sleeve means and wherein a portion of the polished rod extends above the sleeve means dependent on the relative respective portions thereof.

  18. Commercial utility frequency AC to high frequency AC soft switching power conversion circuit with non smoothing DC link for IH dual packs heater

    Microsoft Academic Search

    Hisayuki Sugimura; Tarek Ahmed; Mohamed Orabi; Hyun-Woo Lee; Mutsuo Nakaoka

    2004-01-01

    In this paper, a novel topology of soft switching PWM high frequency AC power conversion conditioning and processing circuit without DC smoothing capacitor filter link from the voltage grid of utility frequency AC power supply source with 60 Hz-100 V or 60 Hz-200 V is proposed and introduced for innovative consumer induction heating (IH) boiler applications as a hot water

  19. Enumerating rigid sphere packings

    E-print Network

    Miranda C. Holmes-Cerfon

    2015-05-08

    Packing problems, which ask how to arrange a collection of objects in space to meet certain criteria, are important in a great many physical and biological systems, where geometrical arrangements at small scales control behaviour at larger ones. In many systems there is no single, optimal packing that dominates, but rather one must understand the entire set of possible packings. As a step in this direction we enumerate rigid clusters of identical hard spheres for $n\\leq 14$, and clusters with the maximum number of contacts for $n\\leq 19$. A rigid cluster is one that cannot be continuously deformed while maintaining all contacts. This is a nonlinear notion that arises naturally because such clusters are the metastable states when the spheres interact with a short-range potential, as is the case in many nano- or micro-scale systems. We expect these lists are nearly complete, except for a small number of highly singular clusters (linearly floppy but nonlinearly rigid.) The data contains some major geometrical surprises, such as the prevalence of hypostatic clusters: those with less than the $3n-6$ contacts generically necessary for rigidity. We discuss these and several other unusual clusters, whose geometries may shed insight into physical mechanisms, pose mathematical and computational problems, or bring inspiration for designing new materials.

  20. Hydraulic dynamic analysis

    NASA Technical Reports Server (NTRS)

    Gale, R. L.; Nease, A. W.; Nelson, D. J.

    1978-01-01

    Computer program mathematically describes complete hydraulic systems to study their dynamic performance. Program employs subroutines that simulate components of hydraulic system, which are then controlled by main program. Program is useful to engineers working with detailed performance results of aircraft, spacecraft, or similar hydraulic systems.

  1. Piezoelectric hydraulic pump performance

    NASA Astrophysics Data System (ADS)

    Mauck, Lisa D.; Oates, William S.; Lynch, Christopher S.

    2001-06-01

    A piezohydraulic pump making use of the step and repeat capability of piezoelectric actuators has been developed for actuation of aircraft control surfaces. The piezohydraulic pump utilizes a piezoelectric stack actuator to drive a piston in a cylinder. The cylinder is fitted with two check valves. On the compression stroke, oil is forced out of the cylinder. On the intake stroke, oil is drawn into the cylinder. The oil is used to drive a linear actuator. The actuator was driven at 7cm/sec with a 271N (61lb) blocking force. To achieve this, the piezoelectric stack actuator was driven at 60Hz with a switching power supply. The system utilizes an accumulator to eliminate cavitation. This work discusses piezohydraulic pumping theory, pump design, and pump performance. Consideration of pump performance includes the effects of varying accumulator pressure, hydraulic oil viscosity, and load imposed on the linear actuator.

  2. Hydraulic type starting clutch

    SciTech Connect

    Ohzono, K.; Hayashi, K.; Saito, M.; Kato, M.; Yoshida, Y.

    1987-07-14

    This patent describes a hydraulic type starting clutch comprising: an input shaft; an input rotating member arranged for rotation in unison with the input shaft; an output shaft; an output rotating member arranged for rotation in unison with the output shaft; friction plates interposed between the input rotating member and the output rotating member for engagement to transmit torque from the input rotating member to the output rotating member; urging means interposed between the friction plates and the output rotating member for urging the friction plates to cause the transmission of torque from the input rotating member to the output rotating member; a hydraulic pressure chamber defined between the urging means and the output rotating member and disposed to be supplied with a hydraulic fluid for acting upon the urging means to urge the friction plates; a hydraulic fluid source for supplying the hydraulic fluid to the hydraulic pressure chamber; pressure regulating valve means for regulating the pressure of the hydraulic fluid in the hydraulic pressure chamber; and control means for controlling the pressure regulating valve means to regulate the pressure of the hydraulic fluid in the hydraulic pressure chamber so as to increase with an increase in the rotational speed of the input shaft, the control means.

  3. Implication of hydraulic properties of bioremediated diesel-contaminated soil.

    PubMed

    Hyun, Seunghun; Ahn, Mi-Youn; Zimmerman, Andrew R; Kim, Minhee; Kim, Jeong-Gyu

    2008-04-01

    The hydraulic properties, such as hydraulic conductivity and water retention, of aged diesel-contaminated and bioremediated soils were examined and implications of the hydraulic properties for assessing bioremediation performance of soils were proposed. Bioremediation of diesel-contaminated soil was performed over 80 d using three treatments; (I) no nutrient added, column-packed soil, (II) nutrient added, column-packed soil, and (III) nutrient added, loosen soil. Diesel reduction in treatment I soil (control soil) was negligible while treatment III showed the greatest extent of diesel biodegradation. All treatments showed greatest rates of diesel biodegradation during the first 20 d, followed by a much retarded biodegradation rate in the remaining incubation period. Reduction of the degradation rate due to entrained diesel within inaccessible soil pores was hypothesized and tested by measuring the hydraulic properties of two column-packed soils (treatments I and II). The hydraulic conductivity of treatment II soil (nutrient added) was consistently above that of treatment I soil (no nutrient added) at pressure heads between 0 and 15 cm. In addition, the water retention of treatment II soil was greater at pressure heads <100 cm (equivalent to pore size of >30 microm), suggesting that biodegradative removal of hydrocarbons results in enhanced wettability of larger soil pores. However, water retention was not significantly different for control and biodegraded soils at pressure heads >100 cm, where smaller size soil pores were responsible for the water retention, indicating that diesel remained in smaller soil pores (e.g., <30 microm). Both incubation kinetics and hydraulic measurements suggest that hydrocarbons located in small pores with limited microbe accessibility may be recalcitrant to bioremediation. PMID:18321559

  4. Low-profile flat pack: a high-power fiber coupled laser diode package for low-cost high-reliability applications

    NASA Astrophysics Data System (ADS)

    Singh, Raj; Heminway, Trebor; Krasnick, Richard; Griffin, Peter; Powers, Michael

    2004-06-01

    In recent years, high power diode lasers have become established in many applications like material processing, fiber laser and amplifier pumping, free space communication, direct printing and medical diagnosis and procedures. In particular, advances in laser diode packaging have resulted in devices with high wall-plug efficiency, enhanced reliability and low cost of ownership. Despite the advances of recent years, packaging, testing and reliability assurance still account for a majority of the cost of a fiber coupled laser diode. At MKPA-Panasonic, we are developing new fiber coupled laser diode package designs to enable low cost, high reliability assemblies that are amenable to high volume manufacturing. In this paper, we present a new low-profile, uncooled package for single-emitter high power laser diode packaging applications. Detailed design information, thermal modeling and reliability data for this small footprint, low profile optical flat package (OFP) with 4W output power in a 0.15NA, 100 micron core fiber is presented. The unique packaging technology resulting in good thermal and reliability performance in uncooled environments is discussed. All the assembly processes for the package are performed in a flux-free environment. The package is devoid of epoxy and can be hermetically sealed for high reliability operation. A reduced bill of materials and assembly steps result in significant cost savings. The design eliminates all non-vertical assembly processes for ease of assembly. Other features include passive die attach and integrated fiber mount. This package is specifically designed to address the fiber laser pump, industrial material processing, solid state laser pumping, printing and medical application markets.

  5. Hydraulic fracture design optimization

    SciTech Connect

    Lee, Tae-Soo; Advani, S.H.

    1992-06-01

    This research and development investigation, sponsored by US DOE and the oil and gas industry, extends previously developed hydraulic fracture geometry models and applied energy related characteristic time concepts towards the optimal design and control of hydraulic fracture geometries. The primary objective of this program is to develop rational criteria, by examining the associated energy rate components during the hydraulic fracture evolution, for the formulation of stimulation treatment design along with real-time fracture configuration interpretation and control.

  6. Hydraulic fracture design optimization

    SciTech Connect

    Advani, S.H.; Lee, T.S. [Lehigh Univ., Bethlehem, PA (United States)

    1992-05-01

    This research and development investigation, sponsored by U.S. DOE and the oil and gas industry, extends previously developed hydraulic fracture geometry models and applies energy related characteristic time concepts towards the optimal design and control of hydraulic fracture geometries. The primary objective of this program is to develop rational criteria, by examining the associated energy rate components during the hydraulic fracture evolution, for the formulation of stimulation treatment design along with real-time fracture configuration interpretation and control.

  7. Hydraulic fracture design optimization

    SciTech Connect

    Lee, Tae-Soo; Advani, S.H.

    1992-01-01

    This research and development investigation, sponsored by US DOE and the oil and gas industry, extends previously developed hydraulic fracture geometry models and applied energy related characteristic time concepts towards the optimal design and control of hydraulic fracture geometries. The primary objective of this program is to develop rational criteria, by examining the associated energy rate components during the hydraulic fracture evolution, for the formulation of stimulation treatment design along with real-time fracture configuration interpretation and control.

  8. Packing-limited growth of irregular objects.

    PubMed

    Dodds, Peter Sheridan; Weitz, Joshua S

    2003-01-01

    We study growth limited by packing for irregular objects in two dimensions. We generate packings by seeding objects randomly in time and space and allowing each object to grow until it collides with another object. The objects we consider allow us to investigate the separate effects of anisotropy and nonunit aspect ratio. By means of a connection to the decay of pore-space volume, we measure power law exponents for the object size distribution. We carry out a scaling analysis, showing that it provides an upper bound for the size distribution exponent. We find that while the details of the growth mechanism are irrelevant, the exponent is strongly shape dependent. Potential applications lie in ecological and biological environments where sessile organisms compete for limited space as they grow. PMID:12636574

  9. The EMSL Hydraulic Properties Apparatus: A Fully Automated Tool for Hydraulic Conductivity and Soil Moisture Retention Determinations

    NASA Astrophysics Data System (ADS)

    Wietsma, T. W.; Oostrom, M.; Covert, M. A.; Fayer, M. J.

    2006-12-01

    Knowledge of hydraulic properties, such as hydraulic conductivity and soil moisture retention, is crucial for understanding flow and contaminant transport in the subsurface. Hydraulic properties are often important input parameters for numerical simulation of flow and transport. Unfortunately, acquisition of these properties is usually time consuming and costly because of the manual labor associated with the currently available laboratory techniques. Another drawback of standard techniques is that different packings or cores are used to determine different properties, which might result in inconsistent data sets. Lately, there has been increased interest in automating laboratory techniques to reduce analysis time and improve data consistency. The newly designed fully automated Hydraulic Properties Apparatus (HPA), located in EMSL's Subsurface Flow and Transport Experimental Laboratory, provides enhanced capabilities. The HPA is unique in that it can determine a consistent set of hydraulic properties for a single packing or core using multiple techniques (i.e., falling- head, constant-head, constant flux, multistep, and soil moisture retention relations). This paper demonstrates the new apparatus and presents data sets for standard laboratory Accusand and a Hanford Site porous media.

  10. Thermally Actuated Hydraulic Pumps

    NASA Technical Reports Server (NTRS)

    Jones, Jack; Ross, Ronald; Chao, Yi

    2008-01-01

    Thermally actuated hydraulic pumps have been proposed for diverse applications in which direct electrical or mechanical actuation is undesirable and the relative slowness of thermal actuation can be tolerated. The proposed pumps would not contain any sliding (wearing) parts in their compressors and, hence, could have long operational lifetimes. The basic principle of a pump according to the proposal is to utilize the thermal expansion and contraction of a wax or other phase-change material in contact with a hydraulic fluid in a rigid chamber. Heating the chamber and its contents from below to above the melting temperature of the phase-change material would cause the material to expand significantly, thus causing a substantial increase in hydraulic pressure and/or a substantial displacement of hydraulic fluid out of the chamber. Similarly, cooling the chamber and its contents from above to below the melting temperature of the phase-change material would cause the material to contract significantly, thus causing a substantial decrease in hydraulic pressure and/or a substantial displacement of hydraulic fluid into the chamber. The displacement of the hydraulic fluid could be used to drive a piston. The figure illustrates a simple example of a hydraulic jack driven by a thermally actuated hydraulic pump. The pump chamber would be a cylinder containing encapsulated wax pellets and containing radial fins to facilitate transfer of heat to and from the wax. The plastic encapsulation would serve as an oil/wax barrier and the remaining interior space could be filled with hydraulic oil. A filter would retain the encapsulated wax particles in the pump chamber while allowing the hydraulic oil to flow into and out of the chamber. In one important class of potential applications, thermally actuated hydraulic pumps, exploiting vertical ocean temperature gradients for heating and cooling as needed, would be used to vary hydraulic pressures to control buoyancy in undersea research vessels. Heretofore, electrically actuated hydraulic pumps have been used for this purpose. By eliminating the demand for electrical energy for pumping, the use of the thermally actuated hydraulic pumps could prolong the intervals between battery charges, thus making it possible to greatly increase the durations of undersea exploratory missions.

  11. What kind of pack and basic packing guide page: What kind of pack

    E-print Network

    Blanchette, Robert A.

    tolerable. ! The Backpack The backpack is with good reason the most common choice for young travelers frame style packs. An external frame pack is more comfortable for long and intensive backpacking. It allows the weight to rest more comfortably on your hips and gives ventilation to keep you cooler

  12. Valve stem and packing assembly

    DOEpatents

    Wordin, J.J.

    1991-09-03

    A valve stem and packing assembly is provided in which a rotatable valve stem includes a first tractrix surface for sliding contact with a stem packing and also includes a second tractrix surface for sliding contact with a bonnet. Force is applied by means of a spring, gland flange, and gland on the stem packing so the stem packing seals to the valve stem and bonnet. This configuration serves to create and maintain a reliable seal between the stem packing and the valve stem. The bonnet includes a second complementary tractrix surface for contacting the second sliding tractrix surface, the combination serving as a journal bearing for the entire valve stem and packing assembly. The journal bearing so configured is known as a Schiele's pivot. The Schiele's pivot also serves to maintain proper alignment of the valve stem with respect to the bonnet. Vertical wear between the surfaces of the Schiele's pivot is uniform at all points of contact between the second sliding tractrix surface and the second complementary tractrix surface of a bonnet. The valve stem is connected to a valve plug by means of a slip joint. The valve is opened and closed by rotating the valve stem. The slip joint compensates for wear on the Schiele's pivot and on the valve plug. A ledge is provided on the valve bonnet for the retaining nut to bear against. The ledge prevents over tightening of the retaining nut and the resulting excessive friction between stem and stem packing. 2 figures.

  13. Valve stem and packing assembly

    DOEpatents

    Wordin, John J. (Bingham County, ID)

    1991-01-01

    A valve stem and packing assembly is provided in which a rotatable valve stem includes a first tractrix surface for sliding contact with a stem packing and also includes a second tractrix surface for sliding contact with a bonnet. Force is applied by means of a spring, gland flange, and gland on the stem packing so the stem packing seals to the valve stem and bonnet. This configuration serves to create and maintain a reliable seal between the stem packing and the valve stem. The bonnet includes a second complementary tractrix surface for contacting the second sliding tractrix surface, the combination serving as a journal bearing for the entire valve stem and packing assembly. The journal bearing so configured is known as a Schiele's pivot. The Schiele's pivot also serves to maintain proper alignment of the valve stem with respect to the bonnet. Vertical wear between the surfaces of the Schiele's pivot is uniform at all points of contact between the second sliding tractrix surface and the second complementary tractrix surface of a bonnet. The valve stem is connected to a valve plug by means of a slip joint. The valve is opened and closed by rotating the valve stem. The slip joint compensates for wear on the Schiele's pivot and on the valve plug. A ledge is provided on the valve bonnet for the retaining nut to bear against. The ledge prevents overtightening of the retaining nut and the resulting excessive friction between stem and stem packing.

  14. Dense periodic packings of tori

    NASA Astrophysics Data System (ADS)

    Gabbrielli, Ruggero; Jiao, Yang; Torquato, Salvatore

    2014-02-01

    Dense packings of nonoverlapping bodies in three-dimensional Euclidean space R3 are useful models of the structure of a variety of many-particle systems that arise in the physical and biological sciences. Here we investigate the packing behavior of congruent ring tori in R3, which are multiply connected nonconvex bodies of genus 1, as well as horn and spindle tori. Specifically, we analytically construct a family of dense periodic packings of unlinked tori guided by the organizing principles originally devised for simply connected solid bodies [22 Torquato and Jiao, Phys. Rev. E 86, 011102 (2012), 10.1103/PhysRevE.86.011102]. We find that the horn tori as well as certain spindle and ring tori can achieve a packing density not only higher than that of spheres (i.e., ? /?18 =0.7404...) but also higher than the densest known ellipsoid packings (i.e., 0.7707...). In addition, we study dense packings of clusters of pair-linked ring tori (i.e., Hopf links), which can possess much higher densities than corresponding packings consisting of unlinked tori.

  15. Downhole hydraulic seismic generator

    Microsoft Academic Search

    D. L. Gregory; H. C. Hardee; D. O. Smallwood

    1990-01-01

    A downhole hydraulic seismic generator system for transmitting energy wave vibrations into earth strata surrounding a borehole. The system contains an elongated, unitary housing operably connected to a well head aboveground by support and electrical cabling, and contains clamping apparatus for selectively clamping the housing to the walls of the borehole. The system further comprises a hydraulic oscillator containing a

  16. Downhole hydraulic seismic generator

    Microsoft Academic Search

    Danny L. Gregory; Harry C. Hardee; David O. Smallwood

    1992-01-01

    A downhole hydraulic seismic generator system for transmitting energy wave vibrations into earth strata surrounding a borehole. The system contains an elongated, unitary housing operably connected to a well head aboveground by support and electrical cabling, and contains clamping apparatus for selectively clamping the housing to the walls of the borehole. The system further comprises a hydraulic oscillator containing a

  17. Downhole hydraulic seismic generator

    DOEpatents

    Gregory, Danny L. (Corrales, NM); Hardee, Harry C. (Albuquerque, NM); Smallwood, David O. (Albuquerque, NM)

    1992-01-01

    A downhole hydraulic seismic generator system for transmitting energy wave vibrations into earth strata surrounding a borehole. The system contains an elongated, unitary housing operably connected to a well head aboveground by support and electrical cabling, and contains clamping apparatus for selectively clamping the housing to the walls of the borehole. The system further comprises a hydraulic oscillator containing a double-actuating piston whose movement is controlled by an electro-servovalve regulating a high pressure hydraulic fluid flow into and out of upper and lower chambers surrounding the piston. The spent hydraulic fluid from the hydraulic oscillator is stored and pumped back into the system to provide high pressure fluid for conducting another run at the same, or a different location within the borehole.

  18. Method for packing chromatographic beds

    DOEpatents

    Freeman, David H. (Potomac, MD); Angeles, Rosalie M. (Germantown, MD); Keller, Suzanne (Rockville, MD)

    1991-01-01

    Column chromatography beds are packed through the application of static force. A slurry of the chromatography bed material and a non-viscous liquid is filled into the column plugged at one end, and allowed to settle. The column is transferred to a centrifuge, and centrifuged for a brief period of time to achieve a predetermined packing level, at a range generally of 100-5,000 gravities. Thereafter, the plug is removed, other fixtures may be secured, and the liquid is allowed to flow out through the bed. This results in an evenly packed bed, with no channeling or preferential flow characteristics.

  19. Packing grains by thermally cycling

    E-print Network

    K. Chen; J. Cole; C. Conger; J. Draskovic; M. Lohr; K. Klein; T. Scheidemantel; P. Schiffer

    2006-08-04

    One of the oldest and most intriguing problems in the handling of materials is how a collection of solid grains packs together. While granular packing is normally determined by how grains are poured or shaken, we find that a systematic and controllable increase in packing is induced by simply raising and lowering the temperature, e.g., without the input of mechanical energy. The results demonstrate that thermal processing provides a largely unexplored mechanism of grain dynamics, as well as an important practical consideration in the handling and storage of granular materials.

  20. 46 CFR 58.30-10 - Hydraulic fluid.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...2012-10-01 2012-10-01 false Hydraulic fluid. 58.30-10 Section 58.30-10...AUXILIARY MACHINERY AND RELATED SYSTEMS Fluid Power and Control Systems § 58.30-10 Hydraulic fluid. (a) The requirements of this...

  1. 46 CFR 58.30-10 - Hydraulic fluid.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...2011-10-01 2011-10-01 false Hydraulic fluid. 58.30-10 Section 58.30-10...AUXILIARY MACHINERY AND RELATED SYSTEMS Fluid Power and Control Systems § 58.30-10 Hydraulic fluid. (a) The requirements of this...

  2. 46 CFR 58.30-10 - Hydraulic fluid.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...2014-10-01 2014-10-01 false Hydraulic fluid. 58.30-10 Section 58.30-10...AUXILIARY MACHINERY AND RELATED SYSTEMS Fluid Power and Control Systems § 58.30-10 Hydraulic fluid. (a) The requirements of this...

  3. 46 CFR 58.30-10 - Hydraulic fluid.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...2013-10-01 2013-10-01 false Hydraulic fluid. 58.30-10 Section 58.30-10...AUXILIARY MACHINERY AND RELATED SYSTEMS Fluid Power and Control Systems § 58.30-10 Hydraulic fluid. (a) The requirements of this...

  4. Trouble-free hydraulic valve package for crane winches

    Microsoft Academic Search

    DeLamatyr

    1983-01-01

    Baker Marine Corporation has been producing hydraulically powered pedestal type cranes for the offshore industry for approximately three years. The original hydraulic system cranes was of the open loop type with multiple gear pumps driven by a single diesel engine. One pump in the stack serviced the main and auxiliary hook winches, while another worked the boom winch, and a

  5. Large-scale simulation of flow and transport in reconstructed HPLC-microchip packings.

    PubMed

    Khirevich, Siarhei; Höltzel, Alexandra; Ehlert, Steffen; Seidel-Morgenstern, Andreas; Tallarek, Ulrich

    2009-06-15

    Flow and transport in a particle-packed microchip separation channel were investigated with quantitative numerical analysis methods, comprising the generation of confined, polydisperse sphere packings by a modified Jodrey-Tory algorithm, 3D velocity field calculations by the lattice-Boltzmann method, and modeling of convective-diffusive mass transport with a random-walk particle-tracking approach. For the simulations, the exact conduit cross section, the particle-size distribution of the packing material, and the respective average interparticle porosity (packing density) of the HPLC-microchip packings was reconstructed. Large-scale simulation of flow and transport at Peclet numbers of up to Pe = 140 in the reconstructed microchip packings (containing more than 3 x 10(5) spheres) was facilitated by the efficient use of supercomputer power. Porosity distributions and fluid flow velocity profiles for the reconstructed microchip packings are presented and analyzed. Aberrations from regular geometrical conduit shape are shown to influence packing structure and, thus, porosity and velocity distributions. Simulated axial dispersion coefficients are discussed with respect to their dependence on flow velocity and bed porosity. It is shown by comparison to experimental separation efficiencies that the simulated data genuinely reflect the general dispersion behavior of the real-life HPLC-microchip packings. Differences between experiment and simulation are explained by differing morphologies of real and simulated packings (intraparticle porosity, packing structure in the corner regions). PMID:19459621

  6. A solid hydraulically amplified piezoelectric microvalve

    NASA Astrophysics Data System (ADS)

    Wu, Xiaosong; Kim, Seong-Hyok; Ji, Chang-Hyeon; Allen, Mark G.

    2011-09-01

    We report a piezoelectrically driven and hydraulically amplified axial polymer microvalve. The microvalve is normally open and is assembled primarily with stereolithographically fabricated polymer components. An incompressible elastomer is used as a solid hydraulic medium to convert the small axial displacement of a piezoelectric actuator into a large valve head stroke while maintaining a large blocking force. Also, the axial design of the microvalve enables densely packed valve arrays. One application of this microvalve is in pneumatic tactile displays, which operates against gas pressure up to approximately 90 kPa and switching speed between 1 and 200 Hz. The current valve design has a maximum static hydraulic amplification ratio of 5 at 30 V driving voltage and a maximum valve head stroke of 37 µm at 150 V. Under a 94.4 kPa differential pressure, the flow rate of the valve and the closing voltage measure are 785 mL min-1 and 150 V, respectively. The function of the microvalve as an on-off switch for a pneumatic microbubble tactile actuator is demonstrated.

  7. AUTOMOTIVE DIESEL MAINTENANCE 2. UNIT IX, AUTOMATIC TRANSMISSIONS--HYDRAULIC SYSTEM (PART I).

    ERIC Educational Resources Information Center

    Human Engineering Inst., Cleveland, OH.

    THIS MODULE OF A 25-MODULE COURSE IS DESIGNED TO DEVELOP AN UNDERSTANDING OF THE OIL FLOW WITHIN HYDRAULIC TRANSMISSIONS USED ON DIESEL POWERED VEHICLES. TOPICS ARE GENERAL DESCRIPTION, HYDRAULIC CIRCUITS, AND BRAKE HYDRAULIC CIRCUIT AND OPERATION. THE MODULE CONSISTS OF A SELF-INSTRUCTIONAL PROGRAMED TRAINING FILM "LEARNING ABOUT THE ALLISON…

  8. Empirical equations for some soil hydraulic properties

    Microsoft Academic Search

    Roger B. Clapp; George M. Hornberger

    1978-01-01

    with a power function relating soil moisture and hydraulic conductivitymis used to derive a formula for the wetting front suction required by the Green-Ampt equation. Representative parameters for the moisture charac- teristic, the wetting front suction, and the sorptivity, a parameter in the infiltration equation derived by Philip (1957), are computed by using the desorption data of Holtan et al.

  9. Hydraulic system design for full hybrid transmission

    Microsoft Academic Search

    Han Bing; Cai Yixi; Zhang Tong

    2011-01-01

    The design method of hydraulic system of power split full hybrid transmission is studied. Oil volume flow and pressure requirement is confirmed according to the vehicle control strategy. Mechanical gear pump and electric pump are used to supply oil flow for all driving modes. Self-adapted pressure regulation circuit is designed to supply high pressure oil for brake engagement. Dynamic model

  10. Suspensions in hydraulic fracturing

    SciTech Connect

    Shah, S.N. [Univ. of Oklahoma, Norman, OK (United States)

    1996-12-31

    Suspensions or slurries are widely used in well stimulation and hydraulic fracturing processes to enhance the production of oil and gas from the underground hydrocarbon-bearing formation. The success of these processes depends significantly upon having a thorough understanding of the behavior of suspensions used. Therefore, the characterization of suspensions under realistic conditions, for their rheological and hydraulic properties, is very important. This chapter deals with the state-of-the-art hydraulic fracturing suspension technology. Specifically it deals with various types of suspensions used in well stimulation and fracturing processes, their rheological characterization and hydraulic properties, behavior of suspensions in horizontal wells, review of proppant settling velocity and proppant transport in the fracture, and presently available measurement techniques for suspensions and their merits. Future industry needs for better understanding of the complex behavior of suspensions are also addressed. 74 refs., 21 figs., 1 tab.

  11. Hydraulic Fracturing Sand

    USGS Multimedia Gallery

    Fine-grained silica sand is mixed with chemicals and water before being pumped into rock formations to prevent the newly created artificial fractures from closing after hydraulic fracturing is completed....

  12. Stable hydraulic pressure regulator

    NASA Technical Reports Server (NTRS)

    Gold, H.

    1979-01-01

    Neither sensing line restrictors nor frictional dampers are required for stability. Analysis presents method by which stability margin, response, and droop magnitude can be incorporated during design of direct-acting hydraulic pressure regulators.

  13. Sleeping distance in wild wolf packs

    USGS Publications Warehouse

    Knick, S.T.; Mech, L.D.

    1980-01-01

    Sleeping distances were observed among members of 13 wild wolf (Canis lupus) packs and 11 pairs in northeastern Minnesota to determine if the distances correlated with pack size and composition. The study utilized aerial radio-tracking and observation during winter. Pack size and number of adults per pack were inversely related to pack average sleeping distance and variability. No correlation between sleeping distance and microclimate was observed. Possible relationships between social bonding and our results are discussed.

  14. Angling hydraulic jumps

    NASA Astrophysics Data System (ADS)

    Belmonte, Andrew; Thiffeault, Jean-Luc

    2008-11-01

    We present an experimental and mathematical study of the normal impact of a jet onto an inclined solid surface, focusing on the characteristics of the hydraulic jump. The angle of the surface is varied between vertical and horizontal positions, using both flat and curved (patterned) surfaces. Comparisons of the outer envelope of the hydraulic jump are made with the ballistic theory and the model of Edwards, Howison, Ockendon, & Ockendon.

  15. United packing: Alcohol feasibility study. Final report

    SciTech Connect

    Not Available

    1981-10-01

    The disposal of cull fruit coming from packing sheds is a large but seasonal solid waste management problem in the Central Valley. Present disposal practices include landfilling, land spreading, and use as animal feed. Typically, these methods represent an economic liability to the packers in addition to being a waste of potential resources. Cull fruit contains significant amounts of sugar which can be converted into ethanol using current technology. The ethanol has several uses, one of which is a fuel to provide on-site energy for plant processing needs. This report was intended to evaluate the potential for ethanol production from cull fruit at United Packing's Sanger plant. However, ethanol production is only one part in an overall energy management plan for the plant. Cogeneration and other power production options utilizing ethanol, to provide both total and partial energy independence from utilities are also examined. Information from the alcohol production evaluation, energy survey, biomass profile, and power production analysis is integrated in the final chapter, and an overall energy management plan is defined.

  16. [Electroflotation packing of mycelial wastes].

    PubMed

    Nikolaev, V B; Karpukhin, V F; Zav'ialova, E V; Faingol'd, Z L

    1989-04-01

    Data on testing a pilot plant for electroflotative packing of mycelial wastes are presented. Both the mycelial wastes and their mixtures were used. Concentration of dry substances raged from 3.5 to 131 g/l. The process was performed with varying flow density and consumption rate of the liquid supplied to the plant. Insoluble magnetite and ruthenium oxide anodes were used. The moister content in the packed phase was 81-97.5 per cent. The study provided specification of the process technological parameters and investigation of the flotator hydroulic characteristics. PMID:2751387

  17. Cylinder valve packing nut studies

    SciTech Connect

    Blue, S.C. [Martin Marietta Energy Systems, Inc., Paducah, KY (United States)

    1991-12-31

    The design, manufacture, and use of cylinder valve packing nuts have been studied to improve their resistance to failure from stress corrosion cracking. Stress frozen photoelastic models have been analyzed to measure the stress concentrations at observed points of failure. The load effects induced by assembly torque and thermal expansion of stem packing were observed by strain gaging nuts. The effects of finishing operations and heat treatment were studied by the strain gage hole boring and X-ray methods. Modifications of manufacturing and operation practices are reducing the frequency of stress corrosion failures.

  18. Simulator for a packing and weighing system of granulated powders.

    PubMed

    Couto Rodrigues de Oliveira, Rafael; Garcia, Claudio

    2013-09-01

    The development of a simulator for a packing and weighing system (PWS) of granulated powder is described. It employed system identification to obtain the deterministic part of the model and stochastic processes to reproduce disturbances. It reproduces the fluctuations in carton weight observed in real packing systems. Its final use is to evaluate proposed improvements in the PWS, aiming at reducing overweight and underweight. Its performance is satisfactory, as the oscillations observed in the carton weights, due to powder density variability, are close to reality as well as the monetary losses due to overweight and underweight and the power spectral density graphs of the real and simulated weights. PMID:23870321

  19. Dense crystalline dimer packings of regular tetrahedra

    E-print Network

    Elizabeth R. Chen; Michael Engel; Sharon C. Glotzer

    2010-07-25

    We present the densest known packing of regular tetrahedra with density phi = 4000/4671 = 0.856347... Like the recently discovered packings of Kallus et al. [arXiv:0910.5226] and Torquato-Jiao [arXiv:0912.4210], our packing is crystalline with a unit cell of four tetrahedra forming two triangular dipyramids (dimer clusters). We show that our packing has maximal density within a three-parameter family of dimer packings. Numerical compressions starting from random configurations suggest that the packing may be optimal at least for small cells with up to 16 tetrahedra and periodic boundaries.

  20. Hydrogen storage for fuel cell systems with stationary applications— I. Transient measurement technique for packed bed evaluation

    Microsoft Academic Search

    S Lévesque; M Ciureanu; R Roberge; Theodore Motyka

    2000-01-01

    Data are presented on a metal hydride storage unit used as a hydrogen source for a 500 W fuel cell power supply system powering the electrical components of a gas furnace. The investigated packed bed had special design features for the internal heat transfer optimization: the hydride material was packed into Al foam, and an inner coaxial U-shaped tube enabled

  1. Geostatistical inference of hydraulic conductivity and dispersivities from hydraulic heads and tracer data

    E-print Network

    Cirpka, Olaf Arie

    Geostatistical inference of hydraulic conductivity and dispersivities from hydraulic heads; accepted 25 April 2006; published 10 August 2006. [1] In groundwater, hydraulic heads and solute arrival times depend primarily on the hydraulic conductivity field and hydraulic boundary conditions. The spread

  2. TU Delft: Hydraulic Engineering

    NSDL National Science Digital Library

    Given the Dutch reputation for water management, it's no surprise that one of their leading technical institutes, The Technische Universiteit Delft, offers a program in Hydraulic Engineering. The website, in both Dutch and English, describes their program as an attempt "to bridge the gap between basic sciences (fluid mechanics and soil mechanics in particular) and practical engineering applications in the design, construction, maintenance, management and eventually the demolition of hydraulic structures." The Education section of the website posts MSc theses completed by their students. The research section describes current and recently completed research projects and includes a listing of publications, some of which are available to download. The website also has a link to a Hydraulic Engineering portal, which offers various publication databases (some in Dutch only), and the Civil Engineering Knowledge Centre, which provides library access and discussion forums for students and staff of Civil Engineering.

  3. Packing tube assembly for pumping wells

    SciTech Connect

    Towner, G.F.; Carter, C.A.

    1987-09-22

    A packing tube assembly for replacing a conventional stuffing box is described. The packing tube assembly comprising: a packing tube; a rod adaptor adapted to be coupled between the polished rod and the sucker rod string and adapted to extend throughout the packing tube when positioned therein; compressible packing means on the rod adaptor adapted to provide a seal between the rod adaptor and the packing tube when the rod adaptor is in position within the packing tube; stabilizing means on the rod adaptor adapted to engage the packing tube to stabilize the rod adaptor within the packing tube during operation; and a mounting bushing connected to the top of the packing tube and adapted to be threaded into the pumping tee to secure the packing tube position within the production tubing string. A method of converting a conventional stuffing box-equipped pumping well to a packing tube-equipped well is described. It consists of: disconnecting the polished rod of the pumping well from the sucker rod string while suspending the sucker rod string within the well by the use of slips; unthreading the conventional stuffing box from the pumping tee of the well and removing the stuffing box; attaching the polished rod to the upper end of a rod adaptor of a packing tube assembly, inserting the rod adaptor with the polished rod attached into the packing tube of the packing tube assembly; aligning the packing tube assembly with the sucker rod string; connecting the lower end of the rod adaptor to the sucker rod string; removing the slips and lowering the packer tube assembly through the pumping tee; and connecting the upper end of the packing tube to the pumping tee.

  4. 48 CFR 211.272 - Alternate preservation, packaging, and packing.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...272 Alternate preservation, packaging, and packing. Use the provision...211-7004, Alternate Preservation, Packaging, and Packing, in solicitations which include military preservation, packaging, or packing specifications...

  5. 48 CFR 211.272 - Alternate preservation, packaging, and packing.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...272 Alternate preservation, packaging, and packing. Use the provision...211-7004, Alternate Preservation, Packaging, and Packing, in solicitations which include military preservation, packaging, or packing specifications...

  6. 48 CFR 211.272 - Alternate preservation, packaging, and packing.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...272 Alternate preservation, packaging, and packing. Use the provision...211-7004, Alternate Preservation, Packaging, and Packing, in solicitations which include military preservation, packaging, or packing specifications...

  7. Wiggling Worms ClassPack

    NSDL National Science Digital Library

    2010-04-23

    Using More Picture-Perfect Science Lessons: Using Children's Books to Guide Inquiry, K-4 in your classroom is easier than ever! NSTA's ClassPacks, each sufficient for a class of 28 students, are lesson-specific collections of materials--an unmatche

  8. Loco Beans ClassPack

    NSDL National Science Digital Library

    2010-04-22

    Using More Picture-Perfect Science Lessons: Using Children's Books to Guide Inquiry, K-4 in your classroom is easier than ever! NSTA's ClassPacks, each sufficient for a class of 28 students, are lesson-specific collections of materials--an unmatche

  9. Roller Coasters ClassPack

    NSDL National Science Digital Library

    2010-04-25

    Using More Picture-Perfect Science Lessons: Using Children's Books to Guide Inquiry, K-4 in your classroom is easier than ever! NSTA's ClassPacks, each sufficient for a class of 28 students, are lesson-specific collections of materials--an unmatche

  10. Imaginative Inventions ClassPack

    NSDL National Science Digital Library

    2010-04-25

    Using More Picture-Perfect Science Lessons: Using Children's Books to Guide Inquiry, K-4 in your classroom is easier than ever! NSTA's ClassPacks, each sufficient for a class of 28 students, are lesson-specific collections of materials--an unmatche

  11. Ecology and Energy Action Pack.

    ERIC Educational Resources Information Center

    McDonald's Corp., Oak Brook, IL.

    One of five McDonald's Action Packs, these elementary school-level instructional materials are for use as an introduction to existing units of study, supplements to a textbook, or a source of special projects for environmental education. Contents include these six units: Make Your Own Ecology Mini-spinner, Let's Look at a Food Chain, Drip the…

  12. Students & Mental Health Resource Pack

    E-print Network

    Stevenson, Mark

    Students & Mental Health Resource Pack Produced by - www.rethink.org/at-ease/ SHEFFIELD EARLY is severe mental illness? 1.4 Treatment and prognosis What is mental health awareness? 2.1 Introduction 2 for students with experience of mental health problems 5.1 Introduction 5.2 Pre-entry guidance for students 5

  13. What Is Hydraulic Fracturing?

    NSDL National Science Digital Library

    2012-01-01

    Hydraulic fracturing is a process used in nine out of 10 natural gas wells in the United States, where millions of gallons of water, sand and chemicals are pumped underground to break apart the rock and release the gas. Scientists are worried that the chemicals used in fracturing may pose a threat either underground or when waste fluids are handled and sometimes spilled on the surface. This poster presentation illustrates the under surface process of hydraulic fracking and the distribution flow to the market.

  14. Hydraulics of wells

    USGS Publications Warehouse

    McLaughlin, Thad G.

    1955-01-01

    Although the subject of this lecture is supposed to be concerned primarily with the hydraulics of wells, Professor Weers has asked that I also discuss the effects tat geological formations have on the quantity and quality of water available to wells. I will discuss the geology of Colorado in relation to the availability and quality of water with particular reference to the most productive aquifers or water-bearing formations in the State. I will then discuss the hydraulics of wells with the aim of emphasizing the differences between water-table and artesian conditions.

  15. Determining the Porosity and Saturated Hydraulic Conductivity of Binary Mixtures

    SciTech Connect

    Zhang, Z. F.; Ward, Anderson L.; Keller, Jason M.

    2009-09-27

    Gravels and coarse sands make up significant portions of some environmentally important sediments, while the hydraulic properties of the sediments are typically obtained in the laboratory using only the fine fraction (e.g., <2 mm or 4.75 mm). Researchers have found that the content of gravel has significant impacts on the hydraulic properties of the bulk soils. Laboratory experiments were conducted to measure the porosity and the saturated hydraulic conductivity of binary mixtures with different fractions of coarse and fine components. We proposed a mixing-coefficient model to estimate the porosity and a power-averaging method to determine the effective particle diameter and further to predict the saturated hydraulic conductivity of binary mixtures. The proposed methods could well estimate the porosity and saturated hydraulic conductivity of the binary mixtures for the full range of gravel contents and was successfully applied to two data sets in the literature.

  16. Packing hyperspheres in high-dimensional Euclidean spaces

    NASA Astrophysics Data System (ADS)

    Skoge, Monica; Donev, Aleksandar; Stillinger, Frank H.; Torquato, Salvatore

    2006-10-01

    We present a study of disordered jammed hard-sphere packings in four-, five-, and six-dimensional Euclidean spaces. Using a collision-driven packing generation algorithm, we obtain the first estimates for the packing fractions of the maximally random jammed (MRJ) states for space dimensions d=4 , 5, and 6 to be ?MRJ?0.46 , 0.31, and 0.20, respectively. To a good approximation, the MRJ density obeys the scaling form ?MRJ=c1/2d+(c2d)/2d , where c1=-2.72 and c2=2.56 , which appears to be consistent with the high-dimensional asymptotic limit, albeit with different coefficients. Calculations of the pair correlation function g2(r) and structure factor S(k) for these states show that short-range ordering appreciably decreases with increasing dimension, consistent with a recently proposed “decorrelation principle,” which, among other things, states that unconstrained correlations diminish as the dimension increases and vanish entirely in the limit d?? . As in three dimensions (where ?MRJ?0.64 ), the packings show no signs of crystallization, are isostatic, and have a power-law divergence in g2(r) at contact with power-law exponent ?0.4 . Across dimensions, the cumulative number of neighbors equals the kissing number of the conjectured densest packing close to where g2(r) has its first minimum. Additionally, we obtain estimates for the freezing and melting packing fractions for the equilibrium hard-sphere fluid-solid transition, ?F?0.32 and ?M?0.39 , respectively, for d=4 , and ?F?0.20 and ?M?0.25 , respectively, for d=5 . Although our results indicate the stable phase at high density is a crystalline solid, nucleation appears to be strongly suppressed with increasing dimension.

  17. 7 CFR 917.13 - Pack.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...MARKETING SERVICE (Marketing Agreements and Orders; Fruits, Vegetables, Nuts), DEPARTMENT OF AGRICULTURE FRESH PEARS AND PEACHES GROWN IN CALIFORNIA Order Regulating Handling Definitions § 917.13 Pack. Pack means the specific...

  18. 7 CFR 917.13 - Pack.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...MARKETING SERVICE (MARKETING AGREEMENTS AND ORDERS; FRUITS, VEGETABLES, NUTS), DEPARTMENT OF AGRICULTURE FRESH PEARS AND PEACHES GROWN IN CALIFORNIA Order Regulating Handling Definitions § 917.13 Pack. Pack means the specific...

  19. 7 CFR 917.13 - Pack.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...MARKETING SERVICE (MARKETING AGREEMENTS AND ORDERS; FRUITS, VEGETABLES, NUTS), DEPARTMENT OF AGRICULTURE FRESH PEARS AND PEACHES GROWN IN CALIFORNIA Order Regulating Handling Definitions § 917.13 Pack. Pack means the specific...

  20. 7 CFR 917.13 - Pack.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...MARKETING SERVICE (Marketing Agreements and Orders; Fruits, Vegetables, Nuts), DEPARTMENT OF AGRICULTURE FRESH PEARS AND PEACHES GROWN IN CALIFORNIA Order Regulating Handling Definitions § 917.13 Pack. Pack means the specific...

  1. 7 CFR 958.16 - Pack.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...Orders; Fruits, Vegetables, Nuts), DEPARTMENT OF AGRICULTURE ONIONS GROWN IN CERTAIN DESIGNATED COUNTIES IN IDAHO, AND MALHEUR...Definitions § 958.16 Pack. Pack means a quantity of onions in any type of container and which falls within specific...

  2. 7 CFR 982.11 - Pack.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...Fruits, Vegetables, Nuts), DEPARTMENT OF AGRICULTURE HAZELNUTS GROWN IN OREGON AND WASHINGTON Order Regulating Handling...internal quality, and external appearance and condition of hazelnuts packed in accordance with any of the pack specifications...

  3. 7 CFR 917.13 - Pack.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...Agreements and Orders; Fruits, Vegetables, Nuts), DEPARTMENT OF AGRICULTURE FRESH PEARS AND PEACHES GROWN IN CALIFORNIA Order Regulating Handling Definitions § 917.13 Pack. Pack means the specific arrangement, size,...

  4. 7 CFR 924.16 - Pack.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...Fruits, Vegetables, Nuts), DEPARTMENT OF AGRICULTURE FRESH PRUNES GROWN IN DESIGNATED COUNTIES IN WASHINGTON AND IN UMATILLA COUNTY, OREGON Order Regulating Handling Definitions § 924.16 Pack. Pack means the specific...

  5. 7 CFR 51.1311 - Packing.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...shall not be allowed in any standard pack. When wrapped, each pear shall be fairly well enclosed by its individual wrapper. (d) Pears packed in round stave bushel baskets, tubs, or in barrels shall be ring...

  6. 7 CFR 51.1270 - Packing.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...bridge shall not be allowed in any standard pack. When wrapped, each pear shall be fairly well enclosed by its individual wrapper. (d) Pears packed in round stave bushel baskets, tubs or in barrels shall be ring...

  7. 21 CFR 890.5700 - Cold pack.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Therapeutic Devices § 890.5700 Cold pack. (a) Identification. A cold pack is a...

  8. 21 CFR 890.5700 - Cold pack.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Therapeutic Devices § 890.5700 Cold pack. (a) Identification. A cold pack...

  9. 21 CFR 890.5700 - Cold pack.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Therapeutic Devices § 890.5700 Cold pack. (a) Identification. A cold pack...

  10. 21 CFR 890.5700 - Cold pack.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Therapeutic Devices § 890.5700 Cold pack. (a) Identification. A cold pack...

  11. 46 CFR 28.405 - Hydraulic equipment.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...Hydraulic equipment. (a) Each hydraulic system must be so designed and installed...operating pressure. (c) Each hydraulic system must be equipped with at least... (d) All material in a hydraulic system must be suitable for use...

  12. 46 CFR 28.405 - Hydraulic equipment.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...Hydraulic equipment. (a) Each hydraulic system must be so designed and installed...operating pressure. (c) Each hydraulic system must be equipped with at least... (d) All material in a hydraulic system must be suitable for use...

  13. 46 CFR 28.405 - Hydraulic equipment.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...Hydraulic equipment. (a) Each hydraulic system must be so designed and installed...operating pressure. (c) Each hydraulic system must be equipped with at least... (d) All material in a hydraulic system must be suitable for use...

  14. 46 CFR 28.405 - Hydraulic equipment.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...Hydraulic equipment. (a) Each hydraulic system must be so designed and installed...operating pressure. (c) Each hydraulic system must be equipped with at least... (d) All material in a hydraulic system must be suitable for use...

  15. 46 CFR 28.880 - Hydraulic equipment.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...Hydraulic equipment. (a) Each hydraulic system must be so designed and installed...operating pressure. (c) Each hydraulic system must be equipped with at least... (d) All material in a hydraulic system must be suitable for use...

  16. Laboratory Determination of Hydraulic Conductivity

    NSDL National Science Digital Library

    From D.B. McWhorterand D. K. Sunda's 1977 Ground-Water Hydrology and Hydraulics, this two page excerpt outlines and details Laboratory Determination of Hydraulic Conductivity. Here, visitors will find illustrations and formula to understand the concept.

  17. Nonlinear elastic stress response in granular packings

    E-print Network

    B. P. Tighe; J. E. S. Socolar

    2007-12-18

    We study the nonlinear elastic response of a two-dimensional material to a localized boundary force, with the particular goal of understanding the differences observed between isotropic granular materials and those with hexagonal anisotropy. Corrections to the classical Boussinesq result for the stresses in an infinite half-space of a linear, isotropic material are developed in a power series in inverse distance from the point of application of the force. The breakdown of continuum theory on scales of order of the grain size is modeled with phenomenological parameters characterizing the strengths of induced multipoles near the point of application of the external force. We find that the data of Geng et al. on isotropic and hexagonal packings of photoelastic grains can be fit within this framework. Fitting the hexagonal packings requires a choice of elastic coefficients with hexagonal anisotropy stronger than that of a simple ball and spring model. For both the isotropic and hexagonal cases, induced dipole and quadrupole terms produce propagation of stresses away from the vertical direction over short distances. The scale over which such propagation occurs is significantly enhanced by the nonlinearities that generate hexagonal anisotropy.

  18. On the kinetics of pack aluminization

    NASA Technical Reports Server (NTRS)

    Gupta, B. K.; Sarkhel, A. K.; Seigle, L. L.

    1975-01-01

    A theory of pack aluminization has been formulated by combining gaseous and solid-state diffusion rates. This theory relates the surface composition of the coating and therefore, in principle, the phase morphology and the growth rate of the coating, to pack operating parameters such as pack aluminum density, type of activator, temperature and others. Experimental data on the aluminization of unalloyed nickel in pure aluminum packs obtained to date are in good agreement with the predictions of the theory.

  19. Cradle modification for hydraulic ram

    SciTech Connect

    Koons, B.M.

    1995-03-02

    The analysis of the cradle hydraulic system considers stress, weld strength, and hydraulic forces required to lift and support the cradle/pump assembly. The stress and weld strength of the cradle modifications is evaluated to ensure that they meet the requirements of the American Institute for Steel Construction (AISC 1989). The hydraulic forces are evaluated to ensure that the hydraulic system is capable of rotating the cradle and pump assembly to the vertical position (between 70{degrees} and 90{degrees}).

  20. Investigation of reliability of hydraulic-robots for hazardous environments using analytic redundancy

    Microsoft Academic Search

    Martin L. Leuschen; Ian D. Walker; Joseph R. Cavallaro

    1999-01-01

    The Rosie mobile worksystem is a robot that is on the cutting edge of hazardous environment robotics. It is a heavy-duty hydraulic robot designed for nuclear reactor decontamination and dismantlement. The robot consists of a wheeled platform containing a central hydraulic power supply powered by an electric tether, four independently steerable wheels, and a heavy-duty crane\\/manipulator. The hydraulic wheel actuator

  1. 7 CFR 51.1217 - Standard pack.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... United States Standards for Grades of Peaches Standard Pack § 51.1217 Standard...Each package shall be packed so that the peaches in the shown face shall be reasonably...the contents of the package. (b) Peaches packed in U.S. Standard bushel...

  2. 7 CFR 51.1217 - Standard pack.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... United States Standards for Grades of Peaches Standard Pack § 51.1217 Standard...Each package shall be packed so that the peaches in the shown face shall be reasonably...the contents of the package. (b) Peaches packed in U.S. Standard bushel...

  3. 7 CFR 51.1217 - Standard pack.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... United States Standards for Grades of Peaches Standard Pack § 51.1217 Standard...Each package shall be packed so that the peaches in the shown face shall be reasonably...the contents of the package. (b) Peaches packed in U.S. Standard bushel...

  4. 7 CFR 51.1217 - Standard pack.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... United States Standards for Grades of Peaches Standard Pack § 51.1217 Standard...Each package shall be packed so that the peaches in the shown face shall be reasonably...the contents of the package. (b) Peaches packed in U.S. Standard bushel...

  5. Viscous Hydraulic Jumps Submitted by

    E-print Network

    Bush, John W.M.

    Viscous Hydraulic Jumps Submitted by Jeffrey M. Aristoff, Jeffrey D. Leblanc, Annette E. Hosoi, and John W. M. Bush, Massachusetts Institute of Technology We examine the form of the viscous hydraulic of height 2­10 mm. Elegaard et al.1 first demonstrated that the axial symme- try of the viscous hydraulic

  6. Hydraulic assist turbocharger system

    SciTech Connect

    Kobayashi, R.J.

    1992-05-19

    This patent describes a turbocharger system for supplying charge air to a combustion engine. It comprises a pair of turbochargers each having a first turbine and compressor mounted on a common shaft for concurrent rotation, the first turbine being adapted to be rotatably driven by exhaust gases from the combustion engine to rotatably drive the compressor to produce charge air for supply to the engine, the turbocharger further including a second turbine mounted on the shaft, the second turbine comprising an hydraulic turbine for rotatably driving the common shaft to rotatably drive the compressor; pump means for producing a supply of hydraulic fluid under pressure; conduit means for delivering the hydraulic fluid under pressure to the second turbine to rotatably drive the second turbine; electrohydraulic control valve means for regulating passage of the hydraulic fluid through the conduit means to selectively control rotatable driving of the shaft by the second turbine in accordance with engine operating parameters; and a common support frame having the pair of turbochargers and the control valve means and the pump means mounted thereon to define a substantially unitary package adapted for facilitated mounting onto the engine.

  7. Integration in Hydraulics.

    ERIC Educational Resources Information Center

    Sworder, Steven C.

    This paper presents an application of integration to the field of hydraulics. An integral relation for the time required to drop the fluid contained in a cylindrical tank from one level to another using a hole in the tank wall is derived. Procedures for constructing the experimental equipment and procedures for determining the coefficient of…

  8. Hydraulic Shutdown Monitor

    NASA Technical Reports Server (NTRS)

    Fleming, S. T.; Harrington, D. B.

    1986-01-01

    Adding switch allows inappropriate control actions to be overridden. Four-pole, double-throw switch added to front panel of controller to disable tracking-error and endpoint-error circuitry yet still retain overload-detection capability. Previously, it was necessary to use adjustable-voltage-level detection equipment connected with cables to hydraulic "dump" or shutdown circuitry in controller.

  9. Water Treatment Technology - Hydraulics.

    ERIC Educational Resources Information Center

    Ross-Harrington, Melinda; Kincaid, G. David

    One of twelve water treatment technology units, this student manual on hydraulics provides instructional materials for three competencies. (The twelve units are designed for a continuing education training course for public water supply operators.) The competencies focus on the following areas: head loss in pipes in series, function loss in…

  10. Force fluctuations in bead packs.

    PubMed

    Liu, C H; Nagel, S R; Schecter, D A; Coppersmith, S N; Majumdar, S; Narayan, O; Witten, T A

    1995-07-28

    Experimental observations and numerical simulations of the large force inhomogeneities present in stationary bead packs are presented. Forces much larger than the mean occurred but were exponentially rare. An exactly soluble model reproduced many aspects of the experiments and simulations. In this model, the fluctuations in the force distribution arise because of variations in the contact angles and the constraints imposed by the force balance on each bead in the pile. PMID:17842361

  11. Improving energy efficiency in robot limbs through hydraulic dangle

    NASA Astrophysics Data System (ADS)

    Whitman, Julian S.; Meller, Mike; Garcia, Ephrahim

    2015-03-01

    Animals often allow their limbs to swing passively under their own inertia. For example, about 40% of a human walking gait consists of the primarily passive swing phase. Current hydraulic robots employ traditional actuation methods in which fluid power is expended for all limb movements, even when passive dynamics could be utilized. "Dangle" is the ability to allow a hydraulic actuator to freely sway in response to external loads, in which both sides of the actuator are disconnected from pressure and connected to the tank. Dangle offers the opportunity for efficiency gains by enabling the use of momentum, gravity, and external loads to move a limb without expending fluid power. To demonstrate these efficiency gains, this paper presents an experiment that compares the fluid power consumed to actuate a two degree of freedom hydraulic leg following a human walking gait cycle trajectory in both a traditional manner and utilizing dangle. It was shown that the use of dangle can decrease fluid power consumption by 20% by utilizing pendular dynamics during the swing phase. At speeds higher than the free dangling rate, more power must be used to maintain the desired trajectory due to damping inherent in the configuration. The use of dangle as a power saving method when driving hydraulic limbs could increase operation time for untethered hydraulic walking robots.

  12. Adhesive Loose Packings of Small Particles

    E-print Network

    Wenwei Liu; Shuiqing Li; Adrian Baule; Hernán A. Makse

    2014-10-08

    We explore adhesive loose packings of dry small spherical particles of micrometer size using 3D discrete-element simulations with adhesive contact mechanics. A dimensionless adhesion parameter ($Ad$) successfully combines the effects of particle velocities, sizes and the work of adhesion, identifying a universal regime of adhesive packings for $Ad>1$. The structural properties of the packings in this regime are well described by an ensemble approach based on a coarse-grained volume function that includes correlations between bulk and contact spheres. Our theoretical and numerical results predict: (i) An equation of state for adhesive loose packings that appears as a continuation from the frictionless random close packing (RCP) point in the jamming phase diagram; (ii) The existence of a maximal loose packing point at the coordination number $Z=2$ and packing fraction $\\phi=1/2^{3}$. Our results highlight that adhesion leads to a universal packing regime at packing fractions much smaller than the random loose packing, which can be described within a statistical mechanical framework. We present a general phase diagram of jammed matter comprising frictionless, frictional, adhesive as well as non-spherical particles, providing a classification of packings in terms of their continuation from the spherical frictionless RCP.

  13. Hydraulic manipulator research at ORNL

    SciTech Connect

    Kress, R.L.; Jansen, J.F. [Oak Ridge National Lab., TN (United States); Love, L.J. [Oak Ridge Inst. for Science and Education, TN (United States)

    1997-03-01

    Recently, task requirements have dictated that manipulator payload capacity increase to accommodate greater payloads, greater manipulator length, and larger environmental interaction forces. General tasks such as waste storage tank cleanup and facility dismantlement and decommissioning require manipulator life capacities in the range of hundreds of pounds rather than tens of pounds. To meet the increased payload capacities demanded by present-day tasks, manipulator designers have turned once again to hydraulics as a means of actuation. In order to successfully design, build, and deploy a new hydraulic manipulator (or subsystem), sophisticated modeling, analysis, and control experiments are usually needed. Oak Ridge National Laboratory (ORNL) has a history of projects that incorporate hydraulics technology, including mobile robots, teleoperated manipulators, and full-scale construction equipment. In addition, to support the development and deployment of new hydraulic manipulators, ORNL has outfitted a significant experimental laboratory and has developed the software capability for research into hydraulic manipulators, hydraulic actuators, hydraulic systems, modeling of hydraulic systems, and hydraulic controls. The purpose of this article is to describe the past hydraulic manipulator developments and current hydraulic manipulator research capabilities at ORNL. Included are example experimental results from ORNL`s flexible/prismatic test stand.

  14. Piezoelectric Hydraulic Pump System Dynamic Model

    Microsoft Academic Search

    William S. Oates; Christopher S. Lynch

    2001-01-01

    A system dynamic model was developed for use in the design of piezohydraulic pumps. The model was implemented in MATLAB to predict the electrical\\/mechanical\\/fluid coupled behavior of the piezoelectric pump system. Model results were used in a performance assessment of a pumping system that was comprised of a stack actuator driven pump, accumulator, power supply, four-way valve, and hydraulic actuator.

  15. Kinetics of pack aluminization of nickel

    NASA Technical Reports Server (NTRS)

    Seigle, L. L.; Gupta, B. K.; Shankar, R.; Sarkhel, A. K.

    1978-01-01

    The kinetics of pack aluminization of unalloyed nickel in packs of varying aluminum activity with various halide activators were studied. Surface compositions of the coatings as functions of time, temperature, and pack composition were obtained in order to establish the boundary conditions for diffusion in the system. The structure of the packs was also examined in order to clarify the mechanism of aluminum transport. The results indicate that the kinetics of pack aluminization are controlled jointly by gas diffusion in the pack and solid diffusion in the coating. Levine and Caves' model for gas diffusion was combined with calculations of rates of diffusion in the solid to formulate a more complete theory for the kinetics of pack aluminization.

  16. Electrical and fluid transport in consolidated sphere packs

    NASA Astrophysics Data System (ADS)

    Zhan, Xin; Schwartz, Lawrence M.; Toksöz, M. Nafi

    2015-05-01

    We calculate geometrical and transport properties (electrical conductivity, permeability, specific surface area, and surface conductivity) of a family of model granular porous media from an image based representation of its microstructure. The models are based on the packing described by Finney and cover a wide range of porosities. Finite difference methods are applied to solve for electrical conductivity and hydraulic permeability. Two image processing methods are used to identify the pore-grain interface and to test correlations linking permeability to electrical conductivity. A three phase conductivity model is developed to compute surface conductivity associated with the grain-pore interface. Our results compare well against empirical models over the entire porosity range studied. We conclude by examining the influence of image resolution on our calculations.

  17. Energy-Saving Control of Single-Rod Hydraulic Cylinders with Programmable Valves and Improved Working Mode Selection

    E-print Network

    Yao, Bin

    states and current states. INTRODUCTION The use of hydraulic systems is widespread throughout industry due to the large power to size ratio. Hydraulic systems are used very heavily in the construction that sophisticated electronic control can be applied to control the system. The control of a hydraulic system is far

  18. Hydraulic root water uptake models: old concerns and new insights

    NASA Astrophysics Data System (ADS)

    Couvreur, V.; Carminati, A.; Rothfuss, Y.; Meunier, F.; Vanderborght, J.; Javaux, M.

    2014-12-01

    Root water uptake (RWU) affects underground water dynamics, with consequences on plant water availability and groundwater recharge. Even though hydrological and climate models are sensitive to RWU parameters, no consensus exists on the modelling of this process. Back in the 1940ies, Van Den Honert's catenary approach was the first to investigate the use of connected hydraulic resistances to describe water flow in whole plants. However concerns such as the necessary computing when architectures get complex made this approach premature. Now that computing power increased dramatically, hydraulic RWU models are gaining popularity, notably because they naturally produce observed processes like compensatory RWU and hydraulic redistribution. Yet major concerns remain. Some are more fundamental: according to hydraulic principles, plant water potential should equilibrate with soil water potential when the plant does not transpire, which is not a general observation when using current definitions of bulk or average soil water potential. Other concerns regard the validation process: water uptake distribution is not directly measurable, which makes it hard to demonstrate whether or not hydraulic models are more accurate than other models. Eventually parameterization concerns exist: root hydraulic properties are not easily measurable, and would even fluctuate on an hourly basis due to processes like aquaporin gating. While offering opportunities to validate hydraulic RWU models, newly developed observation techniques also make us realize the increasing complexity of processes involved in soil-plant hydrodynamics, such as the change of rhizosphere hydraulic properties with soil drying. Surprisingly, once implemented into hydraulic models, these processes do not necessarily translate into more complex emerging behavior at plant scale, and might justify the use of simplified representations of the soil-plant hydraulic system.

  19. Design of a portable hydraulic ankle-foot orthosis.

    PubMed

    Neubauer, Brett C; Nath, Jonathan; Durfee, William K

    2014-08-01

    Small-scale hydraulics is ideal for powered human assistive devices including powered ankle foot orthoses because a large torque can be generated with an actuator that is small and light. A portable hydraulic ankle foot orthosis has been designed and is undergoing preliminary prototyping and engineering bench test evaluation. The device provides 90 Nm of ankle torque and has an operating pressure of 138 bar (2,000 psi). The battery-operated hydraulic power supply weighs about 3 kg and is worn at the waist. The ankle component weighs about 1.2 Kg and connects to the power supply with two hoses. Performance simulation and preliminary bench testing suggests that the device could be useful in certain rehabilitation applications. PMID:25570175

  20. Remotely Adjustable Hydraulic Pump

    NASA Technical Reports Server (NTRS)

    Kouns, H. H.; Gardner, L. D.

    1987-01-01

    Outlet pressure adjusted to match varying loads. Electrohydraulic servo has positioned sleeve in leftmost position, adjusting outlet pressure to maximum value. Sleeve in equilibrium position, with control land covering control port. For lowest pressure setting, sleeve shifted toward right by increased pressure on sleeve shoulder from servovalve. Pump used in aircraft and robots, where hydraulic actuators repeatedly turned on and off, changing pump load frequently and over wide range.

  1. Packed, Printable, and Polymorphic Return-Oriented Programming

    Microsoft Academic Search

    Kangjie Lu; Dabi Zou; Weiping Wen; Debin GAO

    2011-01-01

    Return-oriented programming (ROP) is an attack that has been shown to be able to circumvent W ^X protection. However, it was not clear if ROP can be made as powerful as non-ROP malicious code in other aspects, e.g., be packed to make static analysis difficult, be print- able to evade non-ASCII filtering, be polymorphic to evade signature-based detection, etc. Research

  2. Moving water well: comparing hydraulic efficiency in twigs and trunks of coniferous, ring-porous, and diffuse-

    E-print Network

    Weiblen, George D

    of stem conductivity (Kh) with stem diameter was used to model the hydraulic conductance of the stem network. · Ring-porous trees showed the steepest increase in Kh with stem size. Temperate diffuse. Scaling of Kh was influenced by differences in the allometry of conduit diameter (taper) and packing

  3. Dense packing crystal structures of physical tetrahedra

    E-print Network

    Kallus, Yoav

    2010-01-01

    We present a method for discovering dense packings of general convex hard particles and apply it to study the dense packing behavior of a one-parameter family of particles with tetrahedral symmetry representing a deformation of the ideal mathematical tetrahedron into a less ideal, physical, tetrahedron and all the way to the sphere. Thus, we also connect the two well studied problems of sphere packing and tetrahedron packing on a single axis. Our numerical results uncover a rich optimal-packing behavior, compared to that of other continuous families of particles previously studied. We present four structures as candidates for the optimal packing at different values of the parameter, providing an atlas of crystal structures which might be observed in systems of nano-particles with tetrahedral symmetry.

  4. Application of smart material-hydraulic actuators

    NASA Astrophysics Data System (ADS)

    Anderson, Eric H.; Bales, Gregory L.; White, Edward V.

    2003-08-01

    The application of a new class of actuators is considered. The actuators under development combine a high energy density smart material, specifically a piezoelectric material, with internal servohydraulic components. Large displacement outputs are produced, while the high force capacity of the stiff smart material is retained, for a net high-energy output. The actuator is considered "power-by-wire" because only electrical power is provided from the vehicle or system controller. A primary motivating application is in unmanned combat air vehicles (UCAVs). The particular actuation needs of these vehicles, in flight control and other utility functions, are described and distilled to a set of relevant device requirements. Other potential applications, such as flight motion simulation, are also highlighted. The new actuation architecture offers specific advantages over centralized hydraulic systems and has capabilities not present in electromechanical actuators (EMAs). The main advantage over centralized hydraulic systems is the elimination of the need for hydraulic lines. Compared to motor-driven ball screw type EMAs, the new actuators offer higher frequency response, and a larger peak-to-average output. A laboratory test facility designed to represent the loading experienced by a UCAV control surface is described. Key steps necessary to flight qualify the actuator are introduced.

  5. Close-packing of growing discs

    SciTech Connect

    Bursill, L.A.; Xudong, F. (Melbourne Univ., Parkville (Australia). School of Physics)

    1988-12-01

    Spiral lattices are derived by allowing growing discs to aggregate under a close-packing rule. Both Fibonacci and Lucas numbers of visible spirals arise naturally, dependent only on the choice of growth centre. Both the rate of convergence towards an ideal spiral, and chirality, are determined by the initial placement of the first few discs (initial conditions). Thus the appearance of spiral packings is no more or less mysterious than the appearance of hexagonal packed arrays of equal discs.

  6. Wet packing of crushed rock fine aggregate

    Microsoft Academic Search

    W. W. S. Fung; A. K. H. Kwan; H. H. C. Wong

    2009-01-01

    It is well known that the performance of concrete is dependent on the packing density of the aggregate. All existing methods\\u000a of measuring the packing density of aggregate are carried out under dry condition. However, these dry packing methods are\\u000a sensitive to the amount of compaction applied and do not account for the effect of water in the concrete mix.

  7. Circle Packing for Origami Design Is Hard

    E-print Network

    Demaine, Erik D; Lang, Robert J

    2010-01-01

    We show that deciding whether a given set of circles can be packed into a rectangle, an equilateral triangle, or a unit square are NP-hard problems, settling the complexity of these natural packing problems. On the positive side, we show that any set of circles of total area 1 can be packed into a square of size 8/pi=2.546... These results are motivated by problems arising in the context of origami design.

  8. Diffusion in jammed particle packs

    NASA Astrophysics Data System (ADS)

    Bolintineanu, Dan S.; Silbert, Leonardo E.; Grest, Gary S.; Lechman, Jeremy B.

    2015-03-01

    Diffusive transport in jammed particle packs is of interest for a number of applications, as well as being a potential indicator of structural properties near the jamming point. To this end, we report stochastic simulations of equilibrium diffusion through monodisperse sphere packs near the jamming point in the limit of a perfectly insulating surrounding medium. The time dependence of various diffusion properties is resolved over several orders of magnitude. Two time regimes of expected Fickian diffusion are observed, separated by an intermediate regime of anomalous diffusion. This intermediate regime grows as the particle volume fraction approaches the critical jamming transition. The diffusion behavior is fully controlled by the extent of the contacts between neighboring particles, which in turn depend on proximity to the jamming point. In particular, the mean first passage time associated with the escape of random walkers between neighboring particles is shown to control both the time to recover Fickian diffusion and the long time diffusivity. Scaling laws are established that relate these quantities to the difference between the actual and critical jamming volume fractions. Sandia National Laboratories is a multiprogram laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's NNSA under Contract DE- AC04-94AL85000.

  9. Random packing of spheres in Menger sponge

    NASA Astrophysics Data System (ADS)

    Cie?la, Micha?; Barbasz, Jakub

    2013-06-01

    Random packing of spheres inside fractal collectors of dimension 2 < d < 3 is studied numerically using Random Sequential Adsorption (RSA) algorithm. The paper focuses mainly on the measurement of random packing saturation limit. Additionally, scaling properties of density autocorrelations in the obtained packing are analyzed. The RSA kinetics coefficients are also measured. Obtained results allow to test phenomenological relation between random packing saturation density and collector dimension. Additionally, performed simulations together with previously obtained results confirm that, in general, the known dimensional relations are obeyed by systems having non-integer dimension, at least for d < 3.

  10. Dense crystalline dimer packings of regular tetrahedra

    E-print Network

    Chen, Elizabeth R; Glotzer, Sharon C

    2010-01-01

    We have discovered the densest known packing of regular tetrahedra with a density phi = 4000/4671 = 0.856347.... Like the recently discovered packings of Kallus et al. [arXiv:0910.5226] and Torquato-Jiao [arXiv:0912.4210], our packing is crystalline with a unit cell of four tetrahedra forming two triangular bipyramids (dimer clusters) and is cluster transitive. The densest packing is a special case of an analytical three-parameter family of dimer packings we have constructed. The slightly lower packing densities of phi = 100/117 = 0.854700... (Kallus et al.) and phi = 12250/14319 = 0.855506... (Torquato-Jiao), obtained via analytical one-parameter and two-parameter families of dimer packings, respectively, are shown to be suboptimal cases of our more general formalism. Numerical compressions starting from random configurations confirm that the reported packing is optimal at least for small systems with up to 16 tetrahedra. For all systems with four or more tetrahedra, we obtain packings with densities higher ...

  11. 110. TUBING FOR HYDRAULIC FLUID AT BACK OF HYDRAULIC CONTROL ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    110. TUBING FOR HYDRAULIC FLUID AT BACK OF HYDRAULIC CONTROL PANEL IN UMBILICAL MAST PUMP ROOM (109), LSB (BLDG. 770) ACCUMULATOR FOR MAST RETRACTION ON LEFT. - Vandenberg Air Force Base, Space Launch Complex 3, Launch Pad 3 West, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

  12. 128. TUBING FOR HYDRAULIC FLUID AT BACK OF HYDRAULIC CONTROL ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    128. TUBING FOR HYDRAULIC FLUID AT BACK OF HYDRAULIC CONTROL PANEL IN UMBILICAL MAST PUMP ROOM (209), LSB (BLDG. 751). PUMP ON RIGHT; ACCUMULATOR FOR MAST RETRACTION ON LEFT. - Vandenberg Air Force Base, Space Launch Complex 3, Launch Pad 3 East, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

  13. Field investigation of heat transfer in hydraulic fractures and the effect of heat transfer on fracturing fluid design

    SciTech Connect

    Craig, D.P.; Brown, T.D.; Ely, J.W.

    1996-12-31

    Fracturing fluid temperature is a key variable in the design of hydraulic fracturing treatments and the formulation of fracturing fluids. Heat transfer in a hydraulic fracture dictates the fluid formulation and the concentration of chemical {open_quotes}breakers{close_quotes} used to degrade the fluid and maximize proppant pack conductivity. This paper contains the results of an investigation of heat transfer in hydraulic fractures, and documents the recording of bottomhole temperature during Piceance Basin Mesaverde fracturing treatments and during immediate flow back ({open_quotes}forced closure{close_quotes}). Bottomhole temperature was measured with a gauge set in a perforated interval, and the data shows minimal {open_quotes}cool down{close_quotes} of fracturing fluids, i.e., flow back temperatures increased rapidly to near bottomhole static temperature. Computer simulations are also presented and a fracturing fluid design methodology is suggested which balances fluid rheological requirements with degradation requirements, for maximizing proppant pack conductivity.

  14. Grain Packing Resistance to Particle Mobility

    NASA Astrophysics Data System (ADS)

    Buxton, T. H.; Yager, E.; Buffington, J. M.; Hassan, M. A.; Fremier, A. K.

    2014-12-01

    We report model results for quantifying grain packing resistance to particle motion. Packing resistance was modeled as the difference between the total resistance acting on individual grains (measured with a load cell) and the resistance that occurs when grains interact with the geometry of their resting pocket (measured with a tilt board). Monte Carlo simulations were conducted to develop distributions of packing resistance from observed distributions of total and pocket angle resistance because paired measurements were not available. Results show that packing was the dominant form of resistance to grain motion, exceeding pocket angle resistance by up to 88%. Expressed as coefficients of friction, packing resistance was close to 18 times higher for smaller grains because such particles tend to be more embedded, increasing the extent of packing by surrounding grains. We developed a predictive equation from these data, expressing packing resistance as a function of grain size, embeddedness, and the standard deviation of grain sizes on the bed surface (sorting), which collectively control the frictional surface area of the grain. Including observed values of packing resistance in calculations of critical bed shear stress increased thresholds of grain motion by 8 to 46% (21% on average) over that calculated with pocket angle resistance. This has significant implications for bed load transport predictions, which are typically nonlinear functions of the difference between applied and critical shear stresses; as such, small differences in critical shear stress can cause large prediction errors. Given the importance of packing resistance, future studies are warranted to better understand the physical and biological controls on packing, as well as the mechanics of packing resistance.

  15. Hydraulic and Habitat Suitability Analyses Technical Memorandum

    E-print Network

    Appendix D Hydraulic and Habitat Suitability Analyses Technical Memorandum #12;COPYRIGHT DECEMBER Series 2 and Pond Series 3 Hydraulic and Habitat Suitability Analyses Prepared for Bureau of Reclamation HILL, INC. III Hydraulic and Habitat Suitability Analyses

  16. 14 CFR 23.1435 - Hydraulic systems.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...2011-01-01 2011-01-01 false Hydraulic systems. 23.1435 Section 23.1435 Aeronautics...Miscellaneous Equipment § 23.1435 Hydraulic systems. (a) Design. Each hydraulic system must be designed as follows:...

  17. 14 CFR 29.1435 - Hydraulic systems.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...2011-01-01 2011-01-01 false Hydraulic systems. 29.1435 Section 29.1435 Aeronautics...Miscellaneous Equipment § 29.1435 Hydraulic systems. (a) Design. Each hydraulic system must be designed as follows:...

  18. 14 CFR 27.1435 - Hydraulic systems.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...2012-01-01 2012-01-01 false Hydraulic systems. 27.1435 Section 27.1435 Aeronautics...Equipment Safety Equipment § 27.1435 Hydraulic systems. (a) Design. Each hydraulic system and its elements must withstand,...

  19. 14 CFR 29.1435 - Hydraulic systems.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...2013-01-01 2013-01-01 false Hydraulic systems. 29.1435 Section 29.1435 Aeronautics...Miscellaneous Equipment § 29.1435 Hydraulic systems. (a) Design. Each hydraulic system must be designed as follows:...

  20. 14 CFR 23.1435 - Hydraulic systems.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...2014-01-01 2014-01-01 false Hydraulic systems. 23.1435 Section 23.1435 Aeronautics...Miscellaneous Equipment § 23.1435 Hydraulic systems. (a) Design. Each hydraulic system must be designed as follows:...

  1. 14 CFR 23.1435 - Hydraulic systems.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...2012-01-01 2012-01-01 false Hydraulic systems. 23.1435 Section 23.1435 Aeronautics...Miscellaneous Equipment § 23.1435 Hydraulic systems. (a) Design. Each hydraulic system must be designed as follows:...

  2. 14 CFR 29.1435 - Hydraulic systems.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...2014-01-01 2014-01-01 false Hydraulic systems. 29.1435 Section 29.1435 Aeronautics...Miscellaneous Equipment § 29.1435 Hydraulic systems. (a) Design. Each hydraulic system must be designed as follows:...

  3. 14 CFR 27.1435 - Hydraulic systems.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...2013-01-01 2013-01-01 false Hydraulic systems. 27.1435 Section 27.1435 Aeronautics...Equipment Safety Equipment § 27.1435 Hydraulic systems. (a) Design. Each hydraulic system and its elements must withstand,...

  4. 14 CFR 27.1435 - Hydraulic systems.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...2014-01-01 2014-01-01 false Hydraulic systems. 27.1435 Section 27.1435 Aeronautics...Equipment Safety Equipment § 27.1435 Hydraulic systems. (a) Design. Each hydraulic system and its elements must withstand,...

  5. 14 CFR 27.1435 - Hydraulic systems.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...2011-01-01 2011-01-01 false Hydraulic systems. 27.1435 Section 27.1435 Aeronautics...Equipment Safety Equipment § 27.1435 Hydraulic systems. (a) Design. Each hydraulic system and its elements must withstand,...

  6. 14 CFR 25.1435 - Hydraulic systems.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...2012-01-01 2012-01-01 false Hydraulic systems. 25.1435 Section 25...Miscellaneous Equipment § 25.1435 Hydraulic systems. (a) Element design. Each element of the hydraulic system must be designed...

  7. 14 CFR 25.1435 - Hydraulic systems.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...2014-01-01 2014-01-01 false Hydraulic systems. 25.1435 Section 25...Miscellaneous Equipment § 25.1435 Hydraulic systems. (a) Element design. Each element of the hydraulic system must be designed...

  8. 14 CFR 25.1435 - Hydraulic systems.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...2013-01-01 2013-01-01 false Hydraulic systems. 25.1435 Section 25...Miscellaneous Equipment § 25.1435 Hydraulic systems. (a) Element design. Each element of the hydraulic system must be designed...

  9. 14 CFR 29.1435 - Hydraulic systems.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...2012-01-01 2012-01-01 false Hydraulic systems. 29.1435 Section 29.1435 Aeronautics...Miscellaneous Equipment § 29.1435 Hydraulic systems. (a) Design. Each hydraulic system must be designed as follows:...

  10. 14 CFR 23.1435 - Hydraulic systems.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...2013-01-01 2013-01-01 false Hydraulic systems. 23.1435 Section 23.1435 Aeronautics...Miscellaneous Equipment § 23.1435 Hydraulic systems. (a) Design. Each hydraulic system must be designed as follows:...

  11. Hydraulic Fracturing in Michigan Integrated Assessment

    E-print Network

    Kamat, Vineet R.

    Hydraulic Fracturing in Michigan Integrated Assessment #12;Agenda · Welcome and introduction and timeline · Panel presentation and discussion · Facilitated Q & A · Closing remarks #12;Hydraulic Fracturing · Leverages resources IA BENEFITS Benefits of Integrated Assessment #12;Key Points: · Hydraulic Fracturing (HF

  12. 14 CFR 25.1435 - Hydraulic systems.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...2010-01-01 2010-01-01 false Hydraulic systems. 25.1435 Section 25...Miscellaneous Equipment § 25.1435 Hydraulic systems. (a) Element design. Each element of the hydraulic system must be designed...

  13. 14 CFR 27.1435 - Hydraulic systems.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...2010-01-01 2010-01-01 false Hydraulic systems. 27.1435 Section 27.1435 Aeronautics...Equipment Safety Equipment § 27.1435 Hydraulic systems. (a) Design. Each hydraulic system and its elements must withstand,...

  14. 14 CFR 29.1435 - Hydraulic systems.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...2010-01-01 2010-01-01 false Hydraulic systems. 29.1435 Section 29.1435 Aeronautics...Miscellaneous Equipment § 29.1435 Hydraulic systems. (a) Design. Each hydraulic system must be designed as follows:...

  15. 14 CFR 23.1435 - Hydraulic systems.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...2010-01-01 2010-01-01 false Hydraulic systems. 23.1435 Section 23.1435 Aeronautics...Miscellaneous Equipment § 23.1435 Hydraulic systems. (a) Design. Each hydraulic system must be designed as follows:...

  16. Hydraulic accumulator-motor-generator energy regeneration system for a hybrid hydraulic excavator

    NASA Astrophysics Data System (ADS)

    Lin, Tianliang; Wang, Qingfeng

    2012-11-01

    Though the traditional energy regeneration system(ERS) which used a hydraulic motor and a generator in hybrid excavators can regenerate part of the energy, the power of the motor and the generator should be larger and the time for regenerating energy is so short. At first, the structure of new ERS that combines the advantages of an electric and hydraulic accumulator is analyzed. The energy can be converted into both the electric energy and the hydraulic energy at the lowering of the boom and the generator can still works when the boom stops going down. Then, a method how to set the working pressure of the hydraulic accumulator is proposed. To avoid the excess loss, extra noise and shock pressure, a two-level pressure threshold method that the generator starts to work at the rising edge of the high pressure threshold and stops working at the falling edge of the low pressure threshold is presented to characterize the working mode of the generator. The control strategies on how to control the boom velocity at the lowering of the boom and how to improve the recovery efficiency when the boom stops going down are presented. The test bench of hybrid excavator with ERS is constructed, with which the studies on the influences of ERS on energy conversion efficiency and control performance are carried out. Experimental results show that the proposed ERS features better speed control performance of the boom than traditional ERS. It is also observed that an estimated 45% of the total potential energy could be regenerated at the lowering of the boom in the proposed ERS, and the power level of the generator and the hydraulic motor could be reduced by 60%. Hence, the proposed ERS has obvious advantages over the traditional ERS on the improvement of energy regeneration time, energy efficiency, control performance and economy.

  17. Containment of Massive Hydraulic Fractures

    Microsoft Academic Search

    E. R. Simonson; A. S. Abou-Sayed; R. J. Clifton

    1978-01-01

    Based on two-dimensional analyses of three cases involving the relationship of linear fracture mechanics to the containment of massive hydraulic fractures (MHF), Terra Tek Inc. concluded that the mechanical properties of the pay zone and the barrier formation, as well as the minimum horizontal in situ stresses for these layers, play important roles in the prediction of hydraulic-fracture containment. The

  18. Tractor Hydraulics. A Teaching Reference.

    ERIC Educational Resources Information Center

    American Association for Vocational Instructional Materials, Athens, GA.

    The manual was developed to help provide a better understanding of how and why hydraulic principles serve the purposes of weight reduction, increase of physical effort, and more precise control to machines of all types. The four components that are necessary to have a workable hydraulic system--a reservoir, a pump, a valve, and a motor (cylinder)…

  19. Leaf Hydraulics Lawren Sack1

    E-print Network

    Sack, Lawren

    Leaf Hydraulics Lawren Sack1 and N. Michele Holbrook2 1 Department of Botany, University of Hawai the leaf constitute a substantial (30%) part of the resistance to water flow through plants, and thus influence rates of transpiration and photosynthesis. Leaf hydraulic conductance (Kleaf) varies more than 65

  20. Hydraulics of open channel flow

    Microsoft Academic Search

    Sergio Montes

    1998-01-01

    ``Hydraulics of Open Channel Flow'' provides a complete understanding of open channel flow phenomena, and clearly explains the methods for solving the theoretical equations that represent these phenomena. Researchers and practicing engineers in charge of design of hydraulics structures, generation of hydropower, and computation of pollutant diffusion in channels and lakes will find in this essential reference a wealth of

  1. Voronoia: analyzing packing in protein structures

    Microsoft Academic Search

    Kristian Rother; Peter Werner Hildebrand; Andrean Goede; Bjoern Gruening; Robert Preissner

    2009-01-01

    The packing of protein atoms is an indicator for their stability and functionality, and applied in determin- ing thermostability, in protein design, ligand binding and to identify flexible regions in proteins. Here, we present Voronoia, a database of atomic-scale pack- ing data for protein 3D structures. It is based on an improved Voronoi Cell algorithm using hyperboloid interfaces to construct

  2. Hamiltonian mappings and circle packing phase spaces

    E-print Network

    A. J. Scott; C. A. Holmes; G. J. Milburn

    2001-02-21

    We introduce three area preserving maps with phase space structures which resemble circle packings. Each mapping is derived from a kicked Hamiltonian system with one of three different phase space geometries (planar, hyperbolic or spherical) and exhibits an infinite number of coexisting stable periodic orbits which appear to `pack' the phase space with circular resonances.

  3. Reliability Analysis of Aircraft Air Conditioning Packs

    Microsoft Academic Search

    A. Z. Al-Garni; M. Tozan; A. Kassem; S. Farooq

    Air conditioning packs of aircraft are subject to a number of failures like other aircraft components. However, the number and results of unexpected failures in the Kingdom are expected to be more severe than the corresponding failures in many other countries due to climatic conditions. This paper examines the time-to failure distribution of Boeing 737 air conditioning packs by using

  4. Pack Density Limitations of Hybrid Parachutes

    NASA Technical Reports Server (NTRS)

    Zwicker, Matthew L.; Sinclair, Robert J.

    2013-01-01

    The development and testing of the Orion crew capsule parachute system has provided a unique opportunity to study dense parachute packing techniques and limits, in order to establish a new baseline for future programs. The density of parachute packs has a significant influence on vibration loads, retention system stresses, and parachute mortar performance. Material compositions and pack densities of existing designs for space capsule recovery were compared, using the pack density of the Apollo main parachutes as the current baseline. The composition of parachutes has changed since Apollo, incorporating new materials such as Kevlar , Vectran , Teflon and Spectra . These materials have different specific densities than Nylon, so the densities of hybrid parachute packs cannot be directly compared to Nylon parachutes for determination of feasibility or volume allocation. Six parachute packs were evaluated in terms of weighted average solid density in order to achieve a non-dimensional comparison of packing density. Means of mitigating damage due to packing pressure and mortar firing were examined in light of the Capsule Parachute Assembly System (CPAS) and Apollo experience. Parachute design improvements including incorporation of modern materials and manufacturing processes serves to make CPAS the new knowledge base on which future spacecraft parachute systems will be built.

  5. Is incest common in gray wolf packs?

    Microsoft Academic Search

    Deborah Smith; Thomas Meier; Eli Geffen; L. David Mech; John W. Burch; Layne G. Adams; Robert K. Wayne

    1997-01-01

    Wolf packs generally consist of a breeding pair and their maturing of&pring that help provision and protect pack young. Because the reproductive tenure in wolves is often short, reproductively mature offspring might replace their parents, resulting in sibling or parent-offspr ing matings. To determine the extent of incestuous pairings, we measured relatedness based on variability in 20 microsatellit e loci

  6. Modelling of cooling tower splash pack

    Microsoft Academic Search

    A. A. Dreyer; P. J. Erens

    1996-01-01

    A mathematical model and a computer simulation program have been developed for the modelling of counterflow cooling tower splash pack thermal performance. The one-dimensional model uses basic aerodynamic, hydrodynamic and heat\\/mass transfer information to predict the performance of the packing material without depending on cooling tower test data. The predicted transfer characteristics and pressure drop data obtained with the simulation

  7. Pack rats (Neotoma spp.): Keystone ecological engineers?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The potential role of two species of pack rats (Neotoma albigula and Neotoma micropus) as keystone ecological engineers was examined by estimating the species diversity of invertebrates living in the nest middens, and nitrogen mineralization rates in soils associated with the middens. Although pack-...

  8. SHAPE DETECTION BY PACKING CONTOURS A DISSERTATION

    E-print Network

    Shi, Jianbo

    SHAPE DETECTION BY PACKING CONTOURS Qihui Zhu A DISSERTATION in Computer and Information Science Zhao, Peng Li, Liang Huang, Stephen Tse, John Blitzer, Jinsong Tan, Mengmeng Liu, Zhuowei Bao, Jianzhou SHAPE DETECTION BY PACKING CONTOURS Qihui Zhu Jianbo Shi Humans have an amazing ability to localize

  9. Data Envelopment Analysis Course Welcome Pack

    E-print Network

    Hall, Julian

    1 NATCOR Data Envelopment Analysis Course 28th June 2014 Welcome Pack This pack contains. ABSTRACT Data Envelopment Analysis (DEA) is a rapidly growing area of operational research that deals: Cooper, W. W., L. M. Seiford, K. Tone. 2006. Introduction to Data Envelopment Analysis and Its Uses

  10. Cluster and constraint analysis in tetrahedron packings.

    PubMed

    Jin, Weiwei; Lu, Peng; Liu, Lufeng; Li, Shuixiang

    2015-04-01

    The disordered packings of tetrahedra often show no obvious macroscopic orientational or positional order for a wide range of packing densities, and it has been found that the local order in particle clusters is the main order form of tetrahedron packings. Therefore, a cluster analysis is carried out to investigate the local structures and properties of tetrahedron packings in this work. We obtain a cluster distribution of differently sized clusters, and peaks are observed at two special clusters, i.e., dimer and wagon wheel. We then calculate the amounts of dimers and wagon wheels, which are observed to have linear or approximate linear correlations with packing density. Following our previous work, the amount of particles participating in dimers is used as an order metric to evaluate the order degree of the hierarchical packing structure of tetrahedra, and an order map is consequently depicted. Furthermore, a constraint analysis is performed to determine the isostatic or hyperstatic region in the order map. We employ a Monte Carlo algorithm to test jamming and then suggest a new maximally random jammed packing of hard tetrahedra from the order map with a packing density of 0.6337. PMID:25974480

  11. Particle packing using computational and experimental simulation

    Microsoft Academic Search

    Mohamad Waseem Dekelbab

    2002-01-01

    The prediction of the packing density for a granular mixture is a problem of relevance to cement concrete. It is also relevant to many other industrial sectors (e.g., compacting pills for pharmaceutical industry, packing and storing seeds for agriculture, deposition of natural sand, etc.) Many composite materials like concrete are made of granular material embedded in a binding matrix. The

  12. Cluster and constraint analysis in tetrahedron packings

    NASA Astrophysics Data System (ADS)

    Jin, Weiwei; Lu, Peng; Liu, Lufeng; Li, Shuixiang

    2015-04-01

    The disordered packings of tetrahedra often show no obvious macroscopic orientational or positional order for a wide range of packing densities, and it has been found that the local order in particle clusters is the main order form of tetrahedron packings. Therefore, a cluster analysis is carried out to investigate the local structures and properties of tetrahedron packings in this work. We obtain a cluster distribution of differently sized clusters, and peaks are observed at two special clusters, i.e., dimer and wagon wheel. We then calculate the amounts of dimers and wagon wheels, which are observed to have linear or approximate linear correlations with packing density. Following our previous work, the amount of particles participating in dimers is used as an order metric to evaluate the order degree of the hierarchical packing structure of tetrahedra, and an order map is consequently depicted. Furthermore, a constraint analysis is performed to determine the isostatic or hyperstatic region in the order map. We employ a Monte Carlo algorithm to test jamming and then suggest a new maximally random jammed packing of hard tetrahedra from the order map with a packing density of 0.6337.

  13. The Maximum Resource Bin Packing Problem

    Microsoft Academic Search

    Joan Boyar; Leah Epstein; Lene M. Favrholdt; Jens S. Kohrt; Kim S. Larsen; Morten Monrad Pedersen; Sanne Wøhlk

    2005-01-01

    Usually, for bin packing problems, we try to minimize the number of bins used or in the case of the dual bin packing problem, maximize the number or total size of accepted items. This paper presents results for the opposite problems, where we would like to maximize the number of bins used or minimize the number or total size of

  14. The maximum resource bin packing problem

    Microsoft Academic Search

    Joan Boyar; Leah Epstein; Lene M. Favrholdt; Jens S. Kohrt; Kim S. Larsen; Morten Monrad Pedersen; Sanne Wøhlk

    2006-01-01

    Abstract. Usually, for bin packing problems, we try to minimize the number of bins used or in the case of the dual bin packing problem, maximize the number or total size of accepted items. This paper presents results for the opposite problems, where we would like to maximize the number of bins used or minimize the number,or total size of

  15. Hydraulically actuated well shifting tool

    SciTech Connect

    Roth, B.A.

    1992-10-20

    This patent describes a hydraulically actuated shifting tool for actuating a sliding member in a well tool. It comprises: a housing having a hydraulic fluid bore therein; shifting dog means positioned on the housing for movement away and toward the housing; locking dog means positioned on the housing for movement away and toward the body; shifting dog hydraulic actuating means in fluid communication with the bore for causing engagement of the shifting dogs with the sliding member; locking dog hydraulic actuating means in communication with the bore for causing engagement of the locking dogs with the locking means; and hydraulic shifting means in communication with the bore for causing relative movement between the shifting dog means and the locking dog means for shifting the sliding sleeve.

  16. Powered Remote Manipulators Perform Hazardous Retrieval, Handling, and Size Reduction Operations

    SciTech Connect

    Cole, M.D.; Owen, J.R.; Adams, S.R. [S.A.Robotics, Inc., 3985 S. Lincoln Avenue, Suite 100, Loveland, Colorado 80241 (United States)

    2006-07-01

    This paper describes a new lightweight, powered remote manipulator (PRM) that S.A.Robotics has developed for remote material handling and size reduction in hazardous environments such as reactor decommissioning projects. PRMs can be mounted to various deployment platforms such as remote controlled track-driven vehicles, commercial All Terrain Vehicles, or crane-mounted arms. They can also be installed as replacements for traditional Master-Slave Manipulators (MSMs) in hot cells. The PRM is a six degree of freedom manipulator with carbon fiber structural components that can provide up to a 3 meter (10 foot) reach. Either electric or hydraulic power options can be used and a variety of hydraulic fluids are available to meet combustible material limitations. The PRM is operated with easy-to-use joystick controls that allow operators to sit in a comfortable work station and handle 90 kg (200 pound) loads with a hydraulic power pack or 45 kg (100 pounds) with electric servo-motor driven equipment. With a quick disconnect tool changer, the manipulator can operate grippers, drills, shears, saws, sampling and survey instruments, and the arm can also deploy cameras and lights to support a wide range of remote applications. (authors)

  17. Packing of elastic wires in flexible shells

    E-print Network

    Roman Vetter; Falk K. Wittel; Hans J. Herrmann

    2015-04-03

    The packing problem of long thin filaments that are injected into confined spaces is of fundamental interest for physicists, biologists and materials engineers alike. How linear threads pack and coil is well known only for the ideal case of rigid containers, however. Here, we force long elastic rods into flexible spatial confinement borne by an elastic shell to examine under which conditions recently acquired knowledge on wire packing in rigid spheres breaks down. We find that unlike in rigid cavities, friction plays a key role by giving rise to the emergence of two distinct packing patterns. At low friction, the wire densely coils into an ordered toroidal bundle with semi-ellipsoidal cross section, while at high friction, it packs into a highly disordered, self-similar structure. These two morphologies are shown to be separated by a continuous phase transition.

  18. Packing of elastic wires in flexible shells

    E-print Network

    Vetter, Roman; Herrmann, Hans J

    2015-01-01

    The packing problem of long thin filaments that are injected into confined spaces is of fundamental interest for physicists, biologists and materials engineers alike. How linear threads pack and coil is well known only for the ideal case of rigid containers, however. Here, we force long elastic rods into flexible spatial confinement borne by an elastic shell to examine under which conditions recently acquired knowledge on wire packing in rigid spheres breaks down. We find that unlike in rigid cavities, friction plays a key role by giving rise to the emergence of two distinct packing patterns. At low friction, the wire densely coils into an ordered toroidal bundle with semi-ellipsoidal cross section, while at high friction, it packs into a highly disordered, self-similar structure. These two morphologies are shown to be separated by a continuous phase transition.

  19. Coalescence preference in densely packed microbubbles

    PubMed Central

    Kim, Yeseul; Lim, Su Jin; Gim, Bopil; Weon, Byung Mook

    2015-01-01

    A bubble merged from two parent bubbles with different size tends to be placed closer to the larger parent. This phenomenon is known as the coalescence preference. Here we demonstrate that the coalescence preference can be blocked inside a densely packed cluster of bubbles. We utilized high-speed high-resolution X-ray microscopy to clearly visualize individual coalescence events inside densely packed microbubbles with a local packing fraction of ~40%. The surface energy release theory predicts an exponent of 5 in a relation between the relative coalescence position and the parent size ratio, whereas our observation for coalescence in densely packed microbubbles shows a different exponent of 2. We believe that this result would be important to understand the reality of coalescence dynamics in a variety of packing situations of soft matter. PMID:25583640

  20. Study of compound differential gear train based on pump load hydraulic speed regulation

    Microsoft Academic Search

    Lin Li; Xiaoming Rui; Zhiyong Ma

    2009-01-01

    Based on the operating characteristics of pump load, the hydraulic speed regulation is widely used in the high-power pump load to realize the speed regulation and energy saving. This paper analyzes the energy saving features of the currently-adopted hydraulic speed regulation method in the high-power pump load and the inevitable power loss problems. According to the fundamental features of differential

  1. Monument Creek hydraulics project

    NSDL National Science Digital Library

    Eric Leonard

    Students are given some general questions (file "IntroQuestions_07.pdf") related to project design during the class session before the main project is handed out. They need to use their textbook and/or other class resources to attempt to answer these questions and to prepare to discuss them the next class session. These questions concern field reconstruction of flood hydraulics, specifically. of bankfull flow. At this next class session we discuss their answers to the preliminary questions. Students are then given the main project handout (Monument_Ck_Problem_07.pdf). This gives them the general questions to be answered in the project. After reading it, students brainstorm again as a class about how to go about answering the questions. Students then divide themselves into research of three. These teams will synthesize data together and ultimately write up the project together. Each team then sends one member to join members of other teams to do one of the three main aspects of the field or computer work (1) field identification of the bankfull channel and measurement of bankfull channel geometry, (2) field determination of modern channel roughness from modern stream hydraulics (Manning's n is back-calculated from present channel geometry and flow), (3) development of a flood-frequency curve for this reach of Monument Creek from USGS discharge data. These working groups (with one member from each research team) work initially independently in the field and subsequently doing calculations in the lab, or on the computer. Once each working group has completed what it can do on its own, these groups split up and each member of each group carries the groups results back to his/her research team, and explains to the other members of the research team what he/she has done to this point and what results he/she has for the team. The team then works to synthesize he results into an overall answer to the questions posed at the beginning of the lab (confusing enough for you?). Each research team then writes up the results, sometimes (as in 2007) as a lab write up, in other years in scientific paper format. Whether the project is turned in simply as a lab write up or as a scientific paper, students are always asked to assess sources of error and how they might affect the results. Key words: Fluvial geomorphology, fluvial hydraulics, bankfull discharge, flood-frequency analysis Designed for a geomorphology course

  2. Hydraulic system for a ratio change transmission

    DOEpatents

    Kalns, Ilmars (Northville, MI)

    1981-01-01

    Disclosed is a drive assembly (10) for an electrically powered vehicle (12). The assembly includes a transaxle (16) having a two-speed transmission (40) and a drive axle differential (46) disposed in a unitary housing assembly (38), an oil-cooled prime mover or electric motor (14) for driving the transmission input shaft (42), an adapter assembly (24) for supporting the prime mover on the transaxle housing assembly, and a hydraulic system (172) providing pressurized oil flow for cooling and lubricating the electric motor and transaxle and for operating a clutch (84) and a brake (86) in the transmission to shift between the two-speed ratios of the transmission. The adapter assembly allows the prime mover to be supported in several positions on the transaxle housing. The brake is spring-applied and locks the transmission in its low-speed ratio should the hydraulic system fail. The hydraulic system pump is driven by an electric motor (212) independent of the prime mover and transaxle.

  3. Performance evaluation of a refitted hydraulic press using for water hyacinth dewatering

    Microsoft Academic Search

    Xu Dayong

    2010-01-01

    This article describes the design and construction of a refitted hydraulic press used for water hyacinth dewatering. The performance under different pressures of the press was investigated. The press system mainly composed five parts: support frame, round press plates, cylindrical sieve vessel, collection bucket and hydraulic power system. When the pressure increased from 10 MPa to 35 MPa, the residues

  4. The development, modeling, and testing of a hydraulic topography with integrated energy recovery (TIER)

    Microsoft Academic Search

    John P. Andruch

    2010-01-01

    Current state-of-the art hydraulic systems suffer from poor efficiencies. A significant portion of these losses is due to the power loss across metering valves. Current research trends in hydraulics have been moving in two separate directions. The first movement is towards a displacement control system, while the second movement has been towards independent metering valve systems. The system, called a

  5. AUTOMOTIVE DIESEL MAINTENANCE 2. UNIT X, AUTOMATIC TRANSMISSIONS--HYDRAULIC SYSTEMS (PART II).

    ERIC Educational Resources Information Center

    Human Engineering Inst., Cleveland, OH.

    THIS MODULE OF A 25-MODULE COURSE IS DESIGNED TO PROVIDE A SUMMARY OF MAINTENANCE PROCEDURES FOR AUTOMATIC TRANSMISSIONS USED ON DIESEL POWERED VEHICLES. TOPICS ARE (1) CHECKING THE HYDRAULIC SYSTEM, (2) SERVICING THE HYDRAULIC SYSTEM, (3) EXAMINING THE RANGE CONTROL VALVE, (4) EXAMINING THE LOCK-UP AND FLOW VALVE, (5) EXAMINING THE MAIN REGULATOR…

  6. 29 CFR 1926.305 - Jacks-lever and ratchet, screw, and hydraulic.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...Labor 8 2014-07-01 2014-07-01 false Jacks-lever and ratchet, screw, and hydraulic. 1926.305 Section...CONSTRUCTION Tools-Hand and Power § 1926.305 Jacks—lever and ratchet, screw, and hydraulic. (a) General...

  7. 29 CFR 1926.305 - Jacks-lever and ratchet, screw, and hydraulic.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...Labor 8 2013-07-01 2013-07-01 false Jacks-lever and ratchet, screw, and hydraulic. 1926.305 Section...CONSTRUCTION Tools-Hand and Power § 1926.305 Jacks—lever and ratchet, screw, and hydraulic. (a) General...

  8. 29 CFR 1926.305 - Jacks-lever and ratchet, screw, and hydraulic.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...Labor 8 2011-07-01 2011-07-01 false Jacks-lever and ratchet, screw, and hydraulic. 1926.305 Section...CONSTRUCTION Tools-Hand and Power § 1926.305 Jacks—lever and ratchet, screw, and hydraulic. (a) General...

  9. 29 CFR 1926.305 - Jacks-lever and ratchet, screw, and hydraulic.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...Labor 8 2012-07-01 2012-07-01 false Jacks-lever and ratchet, screw, and hydraulic. 1926.305 Section...CONSTRUCTION Tools-Hand and Power § 1926.305 Jacks—lever and ratchet, screw, and hydraulic. (a) General...

  10. Laboratory imaging of stimulation fluid displacement from hydraulic fractures

    SciTech Connect

    Tidwell, V. [Sandia National Lab., Albuquerque, NM (United States); Parker, M. [SPE, Richardson, TX (United States)

    1996-11-01

    Laboratory experiments were conducted to physically investigate the processes governing stimulation fluid displacement from hydraulic fractures. Experiments were performed on two scales: meter-scale in a 1500 cm{sup 2} sand pack and core-scale in a 65 cm{sup 2} API linear conductivity cell. High-resolution light transmission imaging was employed at the meter-scale to visualize and quantify processes governing fluid displacement. For comparison, complimentary tests were performed using an API conductivity cell under ambient test conditions and at elevated closure stress. In these experiments viscous fingering and gravity drainage were identified as the dominant processes governing fluid displacement. Fluid viscosity was found to dictate the relative importance of the competing displacement processes and ultimately determine the residual liquid saturation of the sand pack. The process by which fluid displacement occurs was seen to effect the shape of both the gas and liquid phase relative permeability functions. Knowledge of such viscosity/relative permeability relationships may prove useful in bounding predictions of post-stimulation recovery of gels from the fracture pack.

  11. Laboratory imaging of stimulation fluid displacement from hydraulic fractures

    SciTech Connect

    Tidwell, V.; Parker, M.

    1996-12-31

    Laboratory experiments were conducted to physically investigate the processes governing stimulation fluid displacement from hydraulic fractures. Experiments were performed on two scales: meter-scale in a 1500 cm{sup 2} sand pack and core-scale in a 65 cm{sup 2} API linear conductivity cell. High-resolution light transmission imaging was employed at the meter-scale to visualize and quantify processes governing liquid displacement. For comparison, complimentary tests were performed using an API conductivity cell under ambient test conditions and at elevated closure stress. In these experiments viscous fingering and gravity drainage were identified as the dominant processes governing liquid displacement. Fluid viscosity was found to dictate the relative importance of the competing displacement processes and ultimately determine the residual liquid saturation of the sand pack. The process by which fluid displacement occurs was seen to affect the shape of both the gas and liquid phase relative permeability functions. Knowledge of such viscosity/relative permeability relationships may prove useful in bounding predictions of post-stimulation recovery of gels from the fracture pack.

  12. VIPRE-01: A thermal-hydraulic code for reactor cores:

    SciTech Connect

    Stewart, C.W.; Cuta, J.M.

    1988-03-01

    VIPRE (Versatile Internals and Component Program for Reactors;EPRI) has been developed for nuclear power utility thermal-hydraulic analysis applications. It is designed to help evaluate nuclear reactor core safety limits including minimum departure from nucleate boiling ratio (NDNBR), critical power ratio (CPR), fuel and clad temperatures, and coolant state in normal operation and assumed accident conditions. This volume discusses general and specific considerations in using VIPRE as a thermal-hydraulic analysis tool. Volume 1: Mathematical Modeling, explains the major thermal-hydraulic models and supporting mathematial correlations in detail. Volume 2: Users's Manual, describes the input requirements of the codes in the VIPRE code package. Volume 3: Programmer's Manual, explains the code structure and computer interface. Experimence in running VIPRE is documented in Volume 4: Applications. 25 refs., 31 figs., 7 tabs.

  13. Performance of Savonius Rotor for Environmentally Friendly Hydraulic Turbine

    NASA Astrophysics Data System (ADS)

    Nakajima, Miyoshi; Iio, Shouichiro; Ikeda, Toshihiko

    The aim of this investigation was to develop an environmentally friendly nano-hydraulic turbine. A model of a two-bucket Savonius type hydraulic turbine was constructed and tested in a water tunnel to arrive at an optimum installation condition. Effects of two installation parameters, namely a distance between a rotor and a bottom wall of the tunnel, a rotation direction of the rotor, on the power performance were studied. A flow field around the rotor was examined visually to clarify influences of installation conditions on the flow field. The flow visualization showed differences of flow pattern around the rotor by the change of these parameters. From this study it was found that the power performances of Savonius hydraulic turbine were changed with the distance between the rotor and the bottom wall of the tunnel and with a rotation direction of the rotor.

  14. Fast Kinetics of Fe2+ Oxidation in Packed-Bed Reactors

    PubMed Central

    Grishin, Sergei I.; Tuovinen, Olli H.

    1988-01-01

    Thiobacillus ferrooxidans was used in fixed-film bioreactors to oxidize ferrous sulfate to ferric sulfate. Glass beads, ion-exchange resin, and activated-carbon particles were tested as support matrix materials. Activated carbon was tested in both a packed-bed bioreactor and a fluidized-bed bioreactor; the other matrix materials were used in packed-bed reactors. Activated carbon displayed the most suitable characteristics for use as a support matrix of T. ferrooxidans fixed-film formation. The reactors were operated within a pH range of 1.35 to 1.5, which effectively reduced the amount of ferric iron precipitation and eliminated diffusion control of mass transfer due to precipitation. The activated-carbon packed-bed reactor displayed the most favorable biomass holdup and kinetic performance related to ferrous sulfate oxidation. The fastest kinetic performance achieved with the activated-carbon packed-bed bioreactor was 78 g of Fe2+ oxidized per liter per h (1,400 mmol of Fe2+ oxidized per liter per h) at a true dilution rate of 40/h, which represents a hydraulic retention time of 1.5 min. PMID:16347798

  15. Hydraulic characteristics of biological filters.

    PubMed

    Muslu, Y

    1991-01-01

    Relationships between the removal efficiency and the hydraulic regimes of trickling filters were investigated. At low flow rates, where break-up of liquid jets occurs and drops form, completely mixed conditions prevail. For large hydraulic loadings effluent concentrations were calculated by means of a dispersed plug flow model. The ranges of validity of these models were studied theoretically. The effects of drop formation and breakage of liquid jets on the substrate utilization are expressed in terms of hydraulic and physical properties of the media and liquid. PMID:1369006

  16. Electrokinetic high pressure hydraulic system

    DOEpatents

    Paul, Phillip H. (Livermore, CA); Rakestraw, David J. (Fremont, CA)

    2000-01-01

    A compact high pressure hydraulic pump having no moving mechanical parts for converting electric potential to hydraulic force. The electrokinetic pump, which can generate hydraulic pressures greater than 2500 psi, can be employed to compress a fluid, either liquid or gas, and manipulate fluid flow. The pump is particularly useful for capillary-base systems. By combining the electrokinetic pump with a housing having chambers separated by a flexible member, fluid flow, including high pressure fluids, is controlled by the application of an electric potential, that can vary with time.

  17. Permeability variation in propped hydraulic fractures with changing fracture stress state in gas reservoirs

    SciTech Connect

    Ochs, D.E.

    1995-12-31

    Most hydraulic fracture design optimization models do not account for any change in the permeability of a propped hydraulic fracture due to the changing stress on the proppant pack with time. The assumption that this change is not significant may cause a serious overprediction of the future production of a fractured well leading to a non-optimal treatment design. This problem is investigated here through the use of an integrated fracture propagation, reservoir production, and economic computer simulation based on published analytical models. This simulation changes the permeability of the hydraulic fracture as the stress on the fracture increases over time, demonstrating the sensitivity of the fracture design optimization process to this parameter in terms of the net present value of the stimulation project.

  18. Leadership in wolf, Canis lupus, packs

    USGS Publications Warehouse

    Mech, L.D.

    2000-01-01

    I examine leadership in Wolf (Canis lupus) packs based on published observations and data gathered during summers from 1986 to 1998 studying a free-ranging pack of Wolves on Ellesmere Island that were habituated to my presence. The breeding male tended to initiate activities associated with foraging and travel, and the breeding female to initiate, and predominate in, pup care and protection. However, there was considerable overlap and interaction during these activities such that leadership could be considered a joint function. In packs with multiple breeders, quantitative information about leadership is needed.

  19. A Hermite cubic collocation scheme for plane strain hydraulic fractures Department of Mathematics, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z2

    E-print Network

    Peirce, Anthony

    A Hermite cubic collocation scheme for plane strain hydraulic fractures A. Peirce Department Accepted 13 February 2010 Available online 4 March 2010 Keywords: Hydraulic fractures Integro the propagation of a hydraulic fracture in a state of plane strain. Special blended cubic Hermite-power­law basis

  20. A Hermite cubic collocation scheme for plane strain hydraulic fractures Department of Mathematics, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z2

    E-print Network

    Peirce, Anthony

    A Hermite cubic collocation scheme for plane strain hydraulic fractures A. Peirce Department Accepted 13 February 2010 Available online xxxx Keywords: Hydraulic fractures Integro-partial differential of a hydraulic fracture in a state of plane strain. Special blended cubic Hermite-power­law basis functions

  1. Ringhals 2 steam control system reliability\\/thermal-hydraulic analysis

    Microsoft Academic Search

    T. Bueter; J. Freeland; R. Reiner; T. Andreychek

    1996-01-01

    This paper evaluates the reliability of the proposed Westinghouse Distributed Processing Family (WDPF) control system and compares it to the reliability of the existing mechanical\\/ hydraulic control system at the Ringhals 2 nuclear power plant. The probabilities of the postulated failures in the existing control system are contrasted to those that would exist for the WDPF enhanced control and protection

  2. Development of a miniaturised hydraulic actuation system for artificial hands

    Microsoft Academic Search

    A. Kargov; T. Werner; C. Pylatiuk; S. Schulz

    2008-01-01

    This article will present a powerful miniaturised hydraulic system of compact design that is used for the actuation of artificial hands. This system was developed as an alternative to today's commonly used electromechanical prosthetic actuation systems. System components and hand prototypes reflect many years of experience of our laboratory in rehabilitation medicine, CAD design and prototyping, mechanical engineering, electronic construction,

  3. Analysis of Small-Scale Hydraulic Actuation Jicheng Xia

    E-print Network

    Durfee, William K.

    of force and power while at the same time being relatively light weight compared to the equivalent to an equivalent electromechanical system comprised of off-the-shelf components. Calculation results revealed that high operating pressures are needed for small-scale hydraulics to be lighter than the equivalent

  4. Hydraulic actuated automotive cooling systems—Nonlinear control and test

    Microsoft Academic Search

    M. H. Salah; P. M. Frick; J. R. Wagner; D. M. Dawson

    2009-01-01

    The replacement of traditional automotive mechanical cooling system components with computer controlled servo-motor driven actuators can improve temperature tracking and reduce parasitic losses. The integration of hydraulic actuators in the engine cooling circuit offers greater power density in a smaller package space when compared with electric actuators. In this paper, a comprehensive nonlinear backstepping robust control technique is developed to

  5. Indirect Adaptive Robust Control of Electro-Hydraulic Systems Driven by Single-Rod Hydraulic Actuator

    E-print Network

    Yao, Bin

    Indirect Adaptive Robust Control of Electro-Hydraulic Systems Driven by Single-Rod Hydraulic) of electro-hydraulic systems driven by single- rod hydraulic actuators. Unlike the tracking that the proposed IARC achieves good tracking performance and accurate parameter estimation. INTRODUCTION Electro-hydraulic

  6. Ensemble smoother assimilation of hydraulic head and return flow data to estimate hydraulic conductivity distribution

    E-print Network

    Bau, Domenico A.

    of transmissivity, hydraulic conductivity, or storativity in an aquifer system given measurements of hydraulic headEnsemble smoother assimilation of hydraulic head and return flow data to estimate hydraulic and data measurements, an ensemble smoother (ES) to provide enhanced estimates of aquifer hydraulic

  7. Hydraulic timer for downhole tool

    SciTech Connect

    Schultz, R.L.; Beck, H.K.

    1992-04-14

    This patent describes a downhole tool apparatus, it comprises: an operating mechanism; a hydraulic timer means, operably associated with the operating mechanism, for providing a time delay prior to operation of the operating mechanism, including: a supply chamber filled with a predetermined volume of hydraulic fluid; a low pressure receiving chamber; a fluid flow restriction communicating the supply chamber with the receiving chamber; a piston means, slidably disposed in the supply chamber, for displacing the hydraulic fluid from the supply chamber through the fluid flow restriction into the receiving chamber; and spring biasing means for moving the piston means through the supply chamber; and mechanism initiation means for starting the hydraulic timer means prior to placement of the apparatus in a well.

  8. Hydraulic drive system prevents backlash

    NASA Technical Reports Server (NTRS)

    Acord, J. D.

    1965-01-01

    Hydraulic drive system uses a second drive motor operating at reduced torque. This exerts a relative braking action which eliminates the normal gear train backlash that is intolerable when driving certain heavy loads.

  9. Cold regions hydrology and hydraulics

    SciTech Connect

    Ryan, W.L. (HDR Engineers, Inc., Anchorage, AK (US)); Crissman, R.D. (NY Power Authority, Niagra Falls, NY (US))

    1990-01-01

    This monograph addresses a narrow aspect of cold regions engineering, namely the effects of cold weather on the traditional civil engineering disciplines of hydrology and hydraulics. Hydrologic and hydraulic considerations in the design, construction, and operation of civil works are very important. Many of the problems encountered in the design and construction of buildings, transportation systems, water supply facilities, waste treatment facilities, and hazardous waste disposal facilities, for example are closely tied to the characteristics of the site hydrology.

  10. Hydraulic Loaders in Forestry Operations

    Microsoft Academic Search

    Peter B. L. Lindgren

    1977-01-01

    I Historical background:Development from horse-skidding, wire cranes to hydraulic loaders.II Application of hydraulic loaders In forestry:Description of the different existing forestry applications and characterisations of different types of loaders.III Forestry loaders versus materials handling cranes:Differences in design and use.IV What are the requirements for a timber loader?Importance of reach, capacity strength, weight, geometry, flexibility and safety aspects.V Prerequisites for producing

  11. Fluid Power

    NSDL National Science Digital Library

    Leske, Cavin.

    2002-01-01

    Hydraulics and pneumatics are both forms of fluid power, a common means of driving and controlling mechanical motions. It is one of the three kinds of power, with the other two being mechanical and electrical. Fluid power systems are widely used in most machinery, such as automobiles and construction equipment.The National Fluid Power Association (1) has an excellent introduction to the topic, which includes a general overview and descriptions of over 20 practical applications. It also looks at the current state of fluid power technology and how it has progressed in recent years. For a more detailed discussion of fluid power principles and how hydraulic and pneumatic devices operate, Integrated Publishing (2) offers twelve chapters of material, complete with diagrams. Fluid Power Web (3) is a comprehensive source of information about components, vendors, and software. Ideas and Applications is an especially interesting section, as it periodically gives a new article about clever, innovative ways of using fluid power systems. Every two months, the Fluid Power Society (4) publishes a journal with a few articles about industry news and trends. Three specialized issues are offered each year, and there is an archive with issues that date back to 1998. A complete hydraulics system is broken down into its constituent parts and explained at this Web site (5). The author uses many drawings and animations to illustrate the physical processes involved in hydraulics. The Institute of Hydraulics and Automation (6), located at the University of Tampere in Finland, has a very active research program with many focus areas. Telerobotics, mobile hydraulics, cavitation, and virtual testing are all investigated at the institute, and project descriptions in each of these areas are given on the site. The Division of Fluid Power Technology (7) at a Swedish university has developed a digital simulation tool for fluid power system design. Called HOPSAN, the software can be freely downloaded from the Web site to run on the Windows operating system (a Fortran compiler is required for Windows 95 and newer). Students at Purdue University (8) have recently built "what is thought to be the first vehicle that uses water in all of its hydraulic systems." This article highlights the students' achievement and considers the rationale behind this original design.

  12. Hydraulic tests of emergency cooling system: L-Area

    SciTech Connect

    Hinton, J H

    1988-01-01

    The delay in L-Area startup provided an opportunity to obtain valuable data on the Emergency Cooling System (ECS) which will permit reactor operation at the highest safe power level. ECS flow is a major input to the FLOOD code which calculates reactor ECS power limits. The FLOOD code assesses the effectiveness of the ECS cooling capacity by modeling the core and plenum hydraulics under accident conditions. Presently, reactor power is not limited by the ECS cooling capacity (power limit). However, the manual calculations of ECS flows had been recently updated to include piping changes (debris strainer, valve changes, pressure release systems) and update fitting losses. Both updates resulted in reduced calculated ECS flows. Upon completion of the current program to update, validate, and document, reactor power may be limited under certain situations by ECS cooling capacity for some present reactor charge designs. A series of special hydraulic tests (Reference 1, 3) were conducted in L-Area using all sources of emergency coolant including the ECS pumps (Reference 2). The tests provided empirical hydraulic data on the ECS piping. These data will be used in computer models of the system as well as manual calculations of ECS flows. The improved modeling and accuracy of the flow calculations will permit reactor operation at the highest safe power level with respect to an ECS power limit.

  13. 7 CFR 920.13 - Pack.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...Fruits, Vegetables, Nuts), DEPARTMENT OF AGRICULTURE KIWIFRUIT GROWN IN CALIFORNIA Definitions § 920.13 Pack. ...arrangement, size, weight, count, or grade of a quantity of kiwifruit in a particular type and size of container, or any...

  14. 7 CFR 29.3538 - Packing.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...AGRICULTURE COMMODITY STANDARDS AND STANDARD CONTAINER REGULATIONS TOBACCO INSPECTION Standards Official Standard Grades for Dark Air-Cured Tobacco (u.s. Types 35, 36, 37 and Foreign Type 95) § 29.3538 Packing. A lot of tobacco...

  15. 7 CFR 29.3538 - Packing.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...AGRICULTURE COMMODITY STANDARDS AND STANDARD CONTAINER REGULATIONS TOBACCO INSPECTION Standards Official Standard Grades for Dark Air-Cured Tobacco (u.s. Types 35, 36, 37 and Foreign Type 95) § 29.3538 Packing. A lot of tobacco...

  16. 7 CFR 29.3538 - Packing.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...AGRICULTURE COMMODITY STANDARDS AND STANDARD CONTAINER REGULATIONS TOBACCO INSPECTION Standards Official Standard Grades for Dark Air-Cured Tobacco (u.s. Types 35, 36, 37 and Foreign Type 95) § 29.3538 Packing. A lot of tobacco...

  17. 7 CFR 29.3538 - Packing.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...AGRICULTURE COMMODITY STANDARDS AND STANDARD CONTAINER REGULATIONS TOBACCO INSPECTION Standards Official Standard Grades for Dark Air-Cured Tobacco (u.s. Types 35, 36, 37 and Foreign Type 95) § 29.3538 Packing. A lot of tobacco...

  18. 7 CFR 29.3538 - Packing.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...AGRICULTURE COMMODITY STANDARDS AND STANDARD CONTAINER REGULATIONS TOBACCO INSPECTION Standards Official Standard Grades for Dark Air-Cured Tobacco (u.s. Types 35, 36, 37 and Foreign Type 95) § 29.3538 Packing. A lot of tobacco...

  19. Finite Element Simulation of Dense Wire Packings

    E-print Network

    R. Vetter; F. K. Wittel; N. Stoop; H. J. Herrmann

    2012-07-03

    A finite element program is presented to simulate the process of packing and coiling elastic wires in two- and three-dimensional confining cavities. The wire is represented by third order beam elements and embedded into a corotational formulation to capture the geometric nonlinearity resulting from large rotations and deformations. The hyperbolic equations of motion are integrated in time using two different integration methods from the Newmark family: an implicit iterative Newton-Raphson line search solver, and an explicit predictor-corrector scheme, both with adaptive time stepping. These two approaches reveal fundamentally different suitability for the problem of strongly self-interacting bodies found in densely packed cavities. Generalizing the spherical confinement symmetry investigated in recent studies, the packing of a wire in hard ellipsoidal cavities is simulated in the frictionless elastic limit. Evidence is given that packings in oblate spheroids and scalene ellipsoids are energetically preferred to spheres.

  20. Groundwater well with reactive filter pack

    DOEpatents

    Gilmore, T.J.; Holdren, G.R. Jr.; Kaplan, D.I.

    1998-09-08

    A method and apparatus are disclosed for the remediation of contaminated soil and ground water wherein a reactive pack material is added to the annular fill material utilized in standard well construction techniques. 3 figs.

  1. Groundwater well with reactive filter pack

    DOEpatents

    Gilmore, Tyler J. (Pasco, WA); Holdren, Jr., George R. (Kennewick, WA); Kaplan, Daniel I. (Richland, WA)

    1998-01-01

    A method and apparatus for the remediation of contaminated soil and ground water wherein a reactive pack material is added to the annular fill material utilized in standard well construction techniques.

  2. Hydraulic release oil tool

    SciTech Connect

    Mims, M.G.; Mueller, M.D.; Ehlinger, J.C.

    1992-03-11

    This patent describes a hydraulic release tool. It comprises a setting assembly; a coupling member for coupling to drill string or petroleum production components, the coupling member being a plurality of sockets for receiving the dogs in the extended position and attaching the coupling member the setting assembly; whereby the setting assembly couples to the coupling member by engagement of the dogs in the sockets of releases from and disengages the coupling member in movement of the piston from its setting to its reposition in response to a pressure in the body in exceeding the predetermined pressure; and a relief port from outside the body into its bore and means to prevent communication between the relief port and the bore of the body axially of the piston when the piston is in the setting position and to establish such communication upon movement of the piston from the setting position to the release position and reduce the pressure in the body bore axially of the piston, whereby the reduction of the pressure signals that the tool has released the coupling member.

  3. Software For Nearly Optimal Packing Of Cargo

    NASA Technical Reports Server (NTRS)

    Fennel, Theron R.; Daughtrey, Rodney S.; Schwaab, Doug G.

    1994-01-01

    PACKMAN computer program used to find nearly optimal arrangements of cargo items in storage containers, subject to such multiple packing objectives as utilization of volumes of containers, utilization of containers up to limits on weights, and other considerations. Automatic packing algorithm employed attempts to find best positioning of cargo items in container, such that volume and weight capacity of container both utilized to maximum extent possible. Written in Common LISP.

  4. Compound hydraulic shear-modulated vortex amplifiers

    NASA Technical Reports Server (NTRS)

    Goldschmied, F. R.

    1977-01-01

    A novel two-stage shear-modulated hydraulic vortex amplifier (U.S. patent 3,520,317) has been fabricated and put through preliminary steady-state testing at the 1000 psi supply pressure level with flows up to 15 gpm. The invention comprises a conventional fluidic vortex power stage and a shear-modulated pilot stage. In the absence of any mechanical moving parts, water may be used as the hydraulic medium thus opening the way to many underseas applications. At blocked load, a control input from 0 to 150 psi was required to achieve an output from 0 to 900 psi; at wide-open load, a control input of 0 to 120 psi was needed to achieve an output from 0 to 15 gpm. The power stage has been found unsuitable for the proportional control mode because of its nonlinear performance in the intermediate load range and because of strong pressure fluctuations (plus or minus 150 psi) in the intermediate control range. The addition of the shear-modulated pilot stage improves intermediate load linearity.

  5. Hydraulic fracture crack propagation driven by a non-Newtonian fluid

    Microsoft Academic Search

    V. R. Tagirova

    2009-01-01

    The problem of hydraulic fracture crack propagation in a porous medium is considered. The fracture is driven by an incompressible\\u000a viscous fluid with a power-law rheology of the pseudoplastic type. The fluid seepage is described by an equation generalizing\\u000a the Darcy law in the hydraulic approximation. It is shown that the system of governing equations has a power-law self-similar\\u000a solution,

  6. Thermal-Hydraulic Design of the Accelerator Production of Tritium Tungsten Neutron Source

    Microsoft Academic Search

    Kemal O. Pasamehmetoglu; Gordon J. Jr. Willcutt; Jay S. Elson; Donald A. Siebe

    2000-01-01

    The thermal-hydraulic design of the accelerator production of tritium (APT) tungsten neutron source is presented. A carefully engineered thermal-hydraulic design is required to remove the deposited power effectively during normal operations and remove the decay power during plant shutdown and postulated accidents. For steady-state operations and operational and anticipated transients, the design criterion is to maintain single-phase flow conditions with

  7. Determining the Molecular Packing Arrangements on Protein Crystal Faces by Atomic Force Microscopy

    NASA Technical Reports Server (NTRS)

    Li, Huayu; Perozzo, Mary A.; Konnert, John H.; Nadarajan, Arunan; Pusey, Marc L.

    1998-01-01

    Periodic Bond Chain (PBC) analysis of the packing of tetragonal lysozyme crystals have revealed that there are two possible molecular packing arrangements for the crystal faces. The analysis also predicted that only one of these, involving the formation of helices about the 4(sub 3) axes, would prevail during crystal growth. In this study high resolution atomic force microscopy (AFM) was employed to verify these predictions for the (110) crystal face. A computer program was developed which constructs the expected AFM image for a given tip shape for each possible molecular packing arrangement. By comparing the actual AFM image with the predicted images the correct packing arrangement was determined. The prediction of an arrangement involving 4(sub 3) helices was confirmed in this manner,"while the alternate arrangement was not observed. The investigation also showed the protein molecules were packed slightly closer about the 4(sub 3) axes than in the crystallographic arrangement of the crystal interior. This study demonstrates a new approach for determining the molecular packing arrangements on protein crystal faces. It also shows the power of combining a theoretical PBC analysis with experimental high resolution AFM techniques in probing protein crystal growth processes at the molecular level.

  8. Dense periodic packings of tetrahedra with small repeating units

    E-print Network

    Yoav Kallus; Veit Elser; Simon Gravel

    2010-03-19

    We present a one-parameter family of periodic packings of regular tetrahedra, with the packing fraction $100/117\\approx0.8547$, that are simple in the sense that they are transitive and their repeating units involve only four tetrahedra. The construction of the packings was inspired from results of a numerical search that yielded a similar packing. We present an analytic construction of the packings and a description of their properties. We also present a transitive packing with a repeating unit of two tetrahedra and a packing fraction $\\frac{139+40\\sqrt{10}}{369}\\approx0.7194$.

  9. Control apparatus for hydraulically driven generator

    SciTech Connect

    Beckwith, S.

    1985-08-06

    Apparatus for controlling a hydraulically driven generator for supplying electrical power to power mains. The generator is coupled to a turbine driven by a fluid flow through a duct. The duct has a one-fourth turn butterfly valve controlled by a fluid-actuated operator and the operator receives fluid from the duct by way of a normally closed valve which, when energized, creates water pressure on the operator for opening the butterfly valve. A second, normally open solenoid provides an emergency exit for the water from the operator to relieve the water pressure thereon and thereby close the butterfly valve when certain conditions exist, such as sudden loss of line voltage, overvoltage or deviation in frequency of the line voltage. A differential pressure switch across the turbine rotor also controls the starting of the system to assure proper flow of fluid through the duct before commencing operation of the generator itself.

  10. 77 FR 55770 - Airworthiness Directives; Cessna Aircraft Company Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-11

    ...from the area of the landing gear's hydraulic power pack system. This proposed AD would require you inspect the aircraft's hydraulic power pack wiring for incorrect installation...from the area of the landing gear's hydraulic power pack system and resulted in a...

  11. Reduction of matrix interferences and improvement of detection power in flame AAS by a high-performance flow\\/hydraulic high-pressure nebulization system for sample introduction (HPF\\/HHPN)

    Microsoft Academic Search

    H. Berndt; A. Müller

    1993-01-01

    For analysis of highly concentrated salt solutions, the samples are injected into a high-performance carrier stream and transported to a special high-pressure nebulization nozzle (max. pressure: 400 bar\\/40 MPa). An aerosol of very small droplets is formed only by the high fluid pressure without using nebulization gas. The nozzle replaces the pneumatic nebulizer (high-performance flow\\/hydraulic high-pressure nebulization system: HPF\\/HHPN). In

  12. Application of new packing material in endoscopic nasal surgery

    PubMed Central

    Yin, Haiying; Han, Fei; Cui, Zhaoyang

    2015-01-01

    Objective: To show the efficacy and comfort of pneumatic bag packing after the endoscopic nasal surgery. Pneumatic bag packing may be recommendable in terms of comfort and efficacy after endoscopic nasal surgery. Significant findings: There were statistical significant differences between the pneumatic bag packing and the expansive sponge packing regarding subjective symptoms and objective findings after surgery. Conclusions: Pneumatic bag packing may be recommendable in terms of comfort and efficacy after endoscopic nasal surgery. PMID:25785173

  13. Inherent Limitations of Hydraulic Tomography

    USGS Publications Warehouse

    Bohling, G.C.; Butler, J.J.

    2010-01-01

    We offer a cautionary note in response to an increasing level of enthusiasm regarding high-resolution aquifer characterization with hydraulic tomography. We use synthetic examples based on two recent field experiments to demonstrate that a high degree of nonuniqueness remains in estimates of hydraulic parameter fields even when those estimates are based on simultaneous analysis of a number of carefully controlled hydraulic tests. We must, therefore, be careful not to oversell the technique to the community of practicing hydrogeologists, promising a degree of accuracy and resolution that, in many settings, will remain unattainable, regardless of the amount of effort invested in the field investigation. No practically feasible amount of hydraulic tomography data will ever remove the need to regularize or bias the inverse problem in some fashion in order to obtain a unique solution. Thus, along with improving the resolution of hydraulic tomography techniques, we must also strive to couple those techniques with procedures for experimental design and uncertainty assessment and with other more cost-effective field methods, such as geophysical surveying and, in unconsolidated formations, direct-push profiling, in order to develop methods for subsurface characterization with the resolution and accuracy needed for practical field applications. Copyright ?? 2010 The Author(s). Journal compilation ?? 2010 National Ground Water Association.

  14. Sound wave velocities in dry and lubricated granular packings packings: numerical simulations and experiments

    E-print Network

    Paris-Sud XI, Université de

    influences the material stiffness more than its density, is notably higher in lubricated packings. 1 INTRODUCTION The mechanical properties of granular packings are sensitive to fine geometric details of the medium, the granular medium is effectively a homogeneous continuum to the prop- agating wave, while

  15. Computer simulations of proppant transport in a hydraulic fracture

    SciTech Connect

    Unwin, A.T.; Hammond, P.S.

    1995-12-31

    The equations of motion of a slurry in a narrow slot, such as a hydraulic fracture, are presented and solved numerically to obtain an estimate of the amount of gravity-driven vertical motion of proppant that can occur within a fracture during placement. Two types of gravity-driven motion are studied: settling of heavy proppant particles; and convective proppant transport, which refers to the motion driven by large-scale density differences between regions of different proppant concentration. Computer simulations are performed using realistic parameter values. In particular, the authors compare the vertical motion of proppant in a slurry in which the proppant particles are uniformly distributed across the fracture width (referred to as homogeneous flow) with that in a slurry in which some unspecified, but rapid, process has caused all the proppant to migrate across the fracture width into a close-packed sheet at the fracture center (referred to as sheet flow).

  16. Deterioration of organic packing materials commonly used in air biofiltration: effect of VOC-packing interactions.

    PubMed

    Lebrero, Raquel; Estrada, José M; Muñoz, Raúl; Quijano, Guillermo

    2014-05-01

    The abiotic deterioration of three conventional organic packing materials used in biofiltration (compost, wood bark and Macadamia nutshells) caused by their interaction with toluene (used as a model volatile organic compound) was here studied. The deterioration of the materials was evaluated in terms of structural damage, release of co-substrates and increase of the packing biodegradability. After 21 days of exposure to toluene, all packing materials released co-substrates able to support microbial growth, which were not released by the control materials not exposed to toluene. Likewise, the exposure to toluene increased the packing material biodegradability by 26% in wood bark, 20% in compost and 17% in Macadamia nutshells. Finally, scanning electron microscopy analysis confirmed the deterioration in the structure of the packing materials evaluated due to the exposure to toluene, Macadamia nutshells being the material with the highest resistance to volatile organic compound attack. PMID:24603032

  17. Inverse modeling of hydraulic tests in fractured crystalline rock based on a transition probability geostatistical approach

    NASA Astrophysics Data System (ADS)

    Blessent, Daniela; Therrien, René; Lemieux, Jean-Michel

    2011-12-01

    This paper presents numerical simulations of a series of hydraulic interference tests conducted in crystalline bedrock at Olkiluoto (Finland), a potential site for the disposal of the Finnish high-level nuclear waste. The tests are in a block of crystalline bedrock of about 0.03 km3 that contains low-transmissivity fractures. Fracture density, orientation, and fracture transmissivity are estimated from Posiva Flow Log (PFL) measurements in boreholes drilled in the rock block. On the basis of those data, a geostatistical approach relying on a transitional probability and Markov chain models is used to define a conceptual model based on stochastic fractured rock facies. Four facies are defined, from sparsely fractured bedrock to highly fractured bedrock. Using this conceptual model, three-dimensional groundwater flow is then simulated to reproduce interference pumping tests in either open or packed-off boreholes. Hydraulic conductivities of the fracture facies are estimated through automatic calibration using either hydraulic heads or both hydraulic heads and PFL flow rates as targets for calibration. The latter option produces a narrower confidence interval for the calibrated hydraulic conductivities, therefore reducing the associated uncertainty and demonstrating the usefulness of the measured PFL flow rates. Furthermore, the stochastic facies conceptual model is a suitable alternative to discrete fracture network models to simulate fluid flow in fractured geological media.

  18. 2D packing using the Myriad framework

    NASA Astrophysics Data System (ADS)

    Chatburn, Luke T.; Batchelor, Bruce G.

    2004-02-01

    Myriad is a framework for building networked and distributed vision systems and is described in a companion paper in this conference. Myriad allows the components of a multi-camera, multi-user vision system (web-cameras, image processing engines, intelligent device controllers, databases and the user interface terminals) to be interconnected and operated together, even if they are physically separated by many hundreds, or thousands, of kilometres. This is achieved by operating them as Internet services. The principal objective in this article is to illustrate the simplicity of harmonising visual control with an existing system using Myriad. However, packing of 2-dimensional blob-like objects is of considerable commercial importance in some industries and involves robotic handling and/or cutting. The shapes to be packed may be cut from sheet metal, glass, cloth, leather, wood, card, paper, composite board, or flat food materials. In addition, many 3D packing applications can realistically be tackled only by regarding them as multi-layer 2D applications. Using Myriad to perform 2D packing, a set of blob-like input objects ("shapes") can be digitised using a standard camera (e.g. a "webcam"). The resulting digital images are then analysed, using a separate processing engine, perhaps located on a different continent. The packing is planned by another processing system, perhaps on a third continent. Finally, the assembly is performed using a robot, usually but not necessarily, located close to the camera.

  19. Study on the Key Image Processing Technology in the Inspection of Packing Quality for Small-Pack Cigarettes

    Microsoft Academic Search

    Hu Fang-xia; He xin; Niu Tian-gui

    2007-01-01

    Image processing is a key factor in the inspection of packing quality by machine vision. Targeting the inspection of packing quality for small-pack cigarettes in tobacco enterprises, this paper proposes a series of key image processing techniques: a fast algorithm for small-pack edge collecting based on fast Hough transformation, an online differentiating algorithm based on GLCM parameters, and packing-flaw detection

  20. Multi-Sized Sphere Packing , , (MPS73-48) Multi-Sized Sphere Packing 2009 3 6 1 / 18

    E-print Network

    Kanno,Jinko

    . . Multi-Sized Sphere Packing 1 2 3 1 2 NTT 3 2009 3 6 , , (MPS73-48) Multi-Sized Sphere Packing 2009 3 6 1 / 18 #12;.. , , (MPS73-48) Multi-Sized Sphere Packing 2009 3 6 2 / 18 #12;.. , , (MPS73-48) Multi-Sized Sphere Packing 2009 3 6 2 / 18 #12;.. , , (MPS73-48) Multi-Sized Sphere Packing 2009 3 6 2

  1. Electrokinetic high pressure hydraulic system

    DOEpatents

    Paul, Phillip H.; Rakestraw, David J.; Arnold, Don W.; Hencken, Kenneth R.; Schoeniger, Joseph S.; Neyer, David W.

    2003-06-03

    An electrokinetic high pressure hydraulic pump for manipulating fluids in capillary-based system. The pump uses electro-osmotic flow to provide a high pressure hydraulic system, having no moving mechanical parts, for pumping and/or compressing fluids, for providing valve means and means for opening and closing valves, for controlling fluid flow rate, and manipulating fluid flow generally and in capillary-based systems (microsystems), in particular. The compact nature of the inventive high pressure hydraulic pump provides the ability to construct a micro-scale or capillary-based HPLC system that fulfills the desire for small sample quantity, low solvent consumption, improved efficiency, the ability to run samples in parallel, and field portability. Control of pressure and solvent flow rate is achieved by controlling the voltage applied to an electrokinetic pump.

  2. Electrokinetic high pressure hydraulic system

    DOEpatents

    Paul, Phillip H. (Livermore, CA); Rakestraw, David J. (Fremont, CA); Arnold, Don W. (Livermore, CA); Hencken, Kenneth R. (Pleasanton, CA); Schoeniger, Joseph S. (Oakland, CA); Neyer, David W. (Castro Valley, CA)

    2001-01-01

    An electrokinetic high pressure hydraulic pump for manipulating fluids in capillary-based systems. The pump uses electro-osmotic flow to provide a high pressure hydraulic system, having no moving mechanical parts, for pumping and/or compressing fluids, for providing valve means and means for opening and closing valves, for controlling fluid flow rate, and manipulating fluid flow generally and in capillary-based systems (Microsystems), in particular. The compact nature of the inventive high pressure hydraulic pump provides the ability to construct a micro-scale or capillary-based HPLC system that fulfills the desire for small sample quantity, low solvent consumption, improved efficiency, the ability to run samples in parallel, and field portability. Control of pressure and solvent flow rate is achieved by controlling the voltage applied to an electrokinetic pump.

  3. Wellhead with hydraulic pump actuator

    SciTech Connect

    Brown, H.D.; Brown, M.A.; Rohling, L.J.

    1984-07-31

    A wellhead assembly especially suited for oil wells has a wide working pressure range and employs three components which fit together to seal the well casing, hold the tubing against high wellhead pressures, and provide a connection to the tubing through which the sucker rods are operated. The primary casing seal is formed by the mating contact of metal surfaces that are not subject to deterioration. The actuator for the subsurface pump is a vertically disposed hydraulic cylinder unit aligned with the sucker rods and forming the uppermost section of an elongated cylindrical housing, which also has a lowermost section on the wellhead that provides the outlets for the fluid pumped from the well, and an intermediate, control section that contains a spool valve for controlling the hydraulic actuator. The spool is shifted by the piston and rod of the hydraulic actuator at the upper and lower limits of their stroke to thereby reciprocate the sucker rods and operate the subsurface pump.

  4. Optimal Core Wrapper Width Selection and SOC Test Scheduling Based on 3-D Bin Packing Algorithm

    Microsoft Academic Search

    Yu Huang; Sudhakar M. Reddy; Wu-tung Cheng; Paul Reuter; Nilanjan Mukherjee; Chien-chung Tsai; Omer Samman; Yahya Zaidan

    2002-01-01

    This paper presents a method to consider a given SOC with pin and peak power constraints, and simultaneously (1) determine an optimal wrapper width for each core, (2) allocate SOC pins to cores and (3) schedule core tests to minimize the test completion time. For the first time the stated problem is formulated as a restricted 3 dimensional bin-packing problem

  5. Reducing hydraulic conductivity of porous media using CaCO? precipitation induced by Sporosarcina pasteurii.

    PubMed

    Eryürük, Ka?an; Yang, Suyin; Suzuki, Daisuke; Sakaguchi, Iwao; Akatsuka, Tetsuji; Tsuchiya, Takayuki; Katayama, Arata

    2015-03-01

    The effect on hydraulic conductivity in porous media of CaCO3 precipitation induced by Sporosarcina pasteurii (ATCC 11859) was investigated using continuous-flow columns containing glass beads between 0.01 mm and 3 mm in diameter. Resting S. pasteurii cells and a precipitation solution composed of 0.5 M CaCl2 and 0.5 M urea were introduced into the columns, and it was shown that the subsequent formation of CaCO3 precipitation reduced hydraulic conductivity from between 8.38 × 10(-1) and 3.27 × 10(-4) cm/s to between 3.70 × 10(-1) and 3.07 × 10(-5) cm/s. The bacterial cells themselves did not decrease the hydraulic conductivity. The amount of precipitation was proportional with the bacterial number in the column. The specific CaCO3 precipitation rate of the resting cells was estimated as 4.0 ± 0.1 × 10(-3) ?g CaCO3/cell. Larger amounts of CaCO3 precipitation were deposited in columns packed with small glass beads than in those packed with large glass beads, resulting in a greater reduction in the hydraulic conductivity of the columns containing small glass beads. Analysis using the Kozeny-Carman equation suggested that the effect of microbially induced CaCO3 precipitation on hydraulic conductivity was not due to the formation of individual CaCO3 crystals but instead that the precipitate aggregated with the glass beads, thus increasing their diameter and consequently decreasing the pore size in the column. PMID:25239069

  6. Hydraulic jumps on an incline

    E-print Network

    Jean-Luc Thiffeault; Andrew Belmonte

    2010-09-01

    When a fluid jet strikes an inclined solid surface at normal incidence, gravity creates a flow pattern with a thick outer rim resembling a parabola and reminiscent of a hydraulic jump. There appears to be little theory or experiments describing simple aspects of this phenomenon, such as the maximum rise height of the fluid above the impact point, and its dependence on jet velocity and inclination angle. We address this with experiments, and present a simple theory based on horizontal hydraulic jumps which accounts for the rise height and its scaling, though without describing the shape of the parabolic envelope.

  7. Electokinetic high pressure hydraulic system

    DOEpatents

    Paul, Phillip H. (Livermore, CA); Rakestraw, David J. (Fremont, CA)

    2000-01-01

    A compact high pressure hydraulic system having no moving parts for converting electric potential to hydraulic force and for manipulating fluids. Electro-osmotic flow is used to provide a valve and means to compress a fluid or gas in a capillary-based system. By electro-osmotically moving an electrolyte between a first position opening communication between a fluid inlet and outlet and a second position closing communication between the fluid inlet and outlet the system can be configured as a valve. The system can also be used to generate forces as large as 2500 psi that can be used to compress a fluid, either a liquid or a gas.

  8. Safety considerations for fabricating lithium battery packs

    NASA Astrophysics Data System (ADS)

    Ciesla, J. J.

    1986-09-01

    Lithium cell safety is a major issue with both manufacturers and end users. Most manufacturers have taken great strides to develop the safest cells possible while still maintaining performance characteristics. The combining of lithium cells for higher voltages, currents, and capacities requires the fabricator of lithium battery packs to be knowledgable about the specific electrochemical system being used. Relatively high rate, spirally wound (large surface area) sulfur oxychloride cells systems, such as Li/Thionyl or Sulfuryl chloride are considered. Prior to the start of a design of a battery pack, a review of the characterization studies for the cells should be conducted. The approach for fabricating a battery pack might vary with cell size.

  9. Safety considerations for fabricating lithium battery packs

    NASA Technical Reports Server (NTRS)

    Ciesla, J. J.

    1986-01-01

    Lithium cell safety is a major issue with both manufacturers and end users. Most manufacturers have taken great strides to develop the safest cells possible while still maintaining performance characteristics. The combining of lithium cells for higher voltages, currents, and capacities requires the fabricator of lithium battery packs to be knowledgable about the specific electrochemical system being used. Relatively high rate, spirally wound (large surface area) sulfur oxychloride cells systems, such as Li/Thionyl or Sulfuryl chloride are considered. Prior to the start of a design of a battery pack, a review of the characterization studies for the cells should be conducted. The approach for fabricating a battery pack might vary with cell size.

  10. Hydraulic jet pumping in a remote location

    SciTech Connect

    Tjondrodiputro, B.; Gaul, R.B.; Gower, G.H.

    1986-12-01

    Hydraulic jet pumping equipment was installed in six Sembakung field (N.E. Kalimantan) wells by Atlantic Richfield Indonesia Inc., for Pertamina during 1983, and this article presents the experience acquired in the process of installing and operating this type of artificial-lift equipment in a remote location. Characteristics of the wells and equipment are reviewed, and possible future installations in similar circumstances are discussed. Sembakung oil field, discovered in late 1975, contained 17 wells after complete development. By 1983, some were flowing weakly and several zones were dead, indicating the need for some form of artificial lift. The choice of artificial lift methods was limited by the lack of gas-lift gas, absence of a field-wide power distribution system, unavailability of a rod pumping well servicing unit, and lack of roads in the marshy environment. Thus, hydraulic (free-type) jet pumping was selected as the optimum technique. Jet pumps were installed in six of 17 wells in the field at the end of 1983. Downhole equipment was installed using a heli-rig, and all surface equipment was delivered to location using helicopters. Since startup, some operating problems occurred, but they have all been resolved. Well pumping rates range from 340 to 650 bpd gross, with 0 to 50% BSandW. The jet-pumped wells produced satisfactorily through July 1984, at which time operations were turned over to Pertamina Unit IV at the conclusion of the contractual term.

  11. 23 CFR 650.111 - Location hydraulic studies.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 2010-04-01 false Location hydraulic studies. 650.111 Section 650...STRUCTURES, AND HYDRAULICS Location and Hydraulic Design of Encroachments on Flood Plains § 650.111 Location hydraulic studies. (a) National...

  12. Dense packing: surgical indications and technical considerations.

    PubMed

    Farjo, Bessam; Farjo, Nilofer

    2013-08-01

    Dense packing is the philosophy of fitting more than 30 to 35 follicular unit grafts per square centimeter in one operation. The aim is to produce a more even, consistent, and natural looking flow of hair after just one procedure. Although desirable in principle, not all patients are suitable candidates nor is it possible to achieve in certain patients (eg, coarse or curly hair). Patients who have sufficient donor availability, reasonably stable hair loss, and high hair-to-skin color ratios are the ideal candidates. The authors highlight their philosophies and strategies for dense packing. PMID:24017984

  13. Confined packings of frictionless spheres and polyhedra

    E-print Network

    Jean-François Camenen; Yannick Descantes; Patrick Richard

    2013-07-22

    By means of numerical simulations, we study the influence of confinement on three-dimensional random close packed (RCP) granular materials subject to gravity. The effects of grain shape (spherical or polyhedral) and polydispersity on this dependence are investigated. In agreement with a simple geometrical model, the solid fraction is found to decrease linearly for increasing confinement no matter the grain shape. This decrease remains valid for bidisperse sphere packings although the gradient seems to reduce significantly when the proportion of small particles reaches 40% by volume. The aforementioned model is extended to capture the effect of the confinement on the coordination number.

  14. Thermo-hydraulic analysis of the gradual cool-down to 80 K of the ITER toroidal field coil

    Microsoft Academic Search

    N. Peng; L. Q. Liu; L. Serio; L. Y. Xiong; L. Zhang

    2009-01-01

    A time-dependent thermo-hydraulic simulation for an ITER toroidal field (TF) coil gradual cool-down to 80K has been performed using a new FORTRAN code. The code is based on a 1D helium flow and 1D multi-region solid heat conduction model. The whole TF coil is simulated taking into account thermal conduction between winding pack and case, which are cooled down separately.

  15. Hydraulic conductivity imaging from 3-D transient hydraulic tomography at several pumping/observation densities

    E-print Network

    Barrash, Warren

    Hydraulic conductivity imaging from 3-D transient hydraulic tomography at several pumping August 2013; accepted 7 September 2013; published 13 November 2013. [1] 3-D Hydraulic tomography (3-D HT (primarily hydraulic conductivity, K) is estimated by joint inversion of head change data from multiple

  16. Creation of multiple sequential hydraulic fractures via hydraulic fracturing combined with controlled pulse fracturing

    Microsoft Academic Search

    Uhri

    1988-01-01

    A method for creating multiple sequential hydraulic fractures via hydraulic fracturing combined with controlled pulse fracturing is described comprising: (a) creating more than two simultaneous multiple vertical radial fractures via a controlled pulse fracturing method; (b) applying thereafter hydraulic pressure to the formation in an amount sufficient to fracture; (c) maintaining the hydraulic pressure on the formation while pumping alternate

  17. Hydraulic circuit construction for a tractor having a hydraulic stepless change speed apparatus

    Microsoft Academic Search

    Ishimori

    1986-01-01

    A hydraulic circuit construction is described for a tractor comprising: a hydraulic stepless change speed means adapted to be driven by an engine through a main clutch and including a charge oil line; a hydraulic pump adapted to be directly driven by the engine; a single-acting hydraulic cylinder for operating a work implement; flow priority valve means to divide pressure

  18. LA-12968-MS The Unsaturated Hydraulic

    E-print Network

    LA-12968-MS The Unsaturated Hydraulic Characteristics of the BandelierTuff LosN A T I O N A L L A B technical correctness. #12;The Unsaturated Hydraulic Characteristics of the Bandelier Tuff David B. Rogers........................................................................................................4 Hydraulic Data Presentation

  19. 4, 37193769, 2007 A model for hydraulic

    E-print Network

    Paris-Sud XI, Université de

    HESSD 4, 3719­3769, 2007 A model for hydraulic redistribution G. G. Amenu and P. Kumar Title Page are under open-access review for the journal Hydrology and Earth System Sciences A model for hydraulic;HESSD 4, 3719­3769, 2007 A model for hydraulic redistribution G. G. Amenu and P. Kumar Title Page

  20. Hydraulic conductivity tests on compacted clay

    Microsoft Academic Search

    Stephen S. Boynton; David E. Daniel

    1985-01-01

    Permeability tests were performed in the laboratory on compacted clay to study the effects of type of permeameter, hydraulic anisotropy, diameter of test specimens, storage time, and desiccation cracking. Essentially identical hydraulic conductivities were measured with compaction-mold, consolidationcell, and flexible-wall permeameters. With good bonding between lifts, hydraulic conductivity was isotropic. Test specimens having a diameter of 15 cm were twice

  1. Numerical Study of a Turbulent Hydraulic Jump

    E-print Network

    Zhao, Qun

    Numerical Study of a Turbulent Hydraulic Jump Qun Zhao, Shubhra Misra, Ib. A. Svendsen and James T of a Turbulent Hydraulic Jump ­ p.1/14 #12;Objective Our ultimate goal is to study the breaking waves. Numerical Study of a Turbulent Hydraulic Jump ­ p.2/14 #12;A moving bore Qiantang Bore China (Courtesy of Dr J

  2. Hydraulic actuator motion limiter ensures operator safety

    NASA Technical Reports Server (NTRS)

    Steinmetz, C. P.

    1971-01-01

    Device regulates action of hydraulic linkage to control column to minimize hazard to operator. Primary components of device are flow rate control valve, limiter accumulator, and shutoff valve. Limiter may be incorporated into other hydraulic systems to prevent undue wear on hydraulic actuators and associated components.

  3. Research on One Borehole Hydraulic Coal Mining System

    NASA Astrophysics Data System (ADS)

    XIA, Bairu; ZENG, Xiping; MAO, Zhixin

    The Borehole Hydraulic Coal Mining System (BHCMS) causes fragmentation of coal seams and removes coal slump through a drilled hole using high-pressure water jet. Then the mixture of coal and water as slurry are driven out of the borehole by hydraulic or air-lifting method, and are separated at the surface. This paper presents a case study of hydraulic borehole coal mining. The three key techniques of the BHCMS, namely, hydraulic lift of jet pump, air lift, and water jet disintegration are discussed and analyzed in this paper based on theoretical analysis and field experiments. Some useful findings have been obtained: (1) The design of jet pump, air lift system, and water jet has to be integrated appropriately in order to improve mining efficiency and coal recovery rate, and to decrease energy consumption. The design of hydraulic lift jet pump must meet the requirement of the minimum floating speed of coal particles. The optimization of nondimensional parameters and prevention of cavitation have to be considered in the design; (2) With regard to selecting the nozzle types of jet pump, center nozzle or annular nozzle can be selected according to the size of the removed particles; (3) Through air-lift and back pressure, the water head can be decreased to improve the lift capacity of jet pump and decrease the power loss. The air lift has great limitation if it is used solely to extract coal, but if it is employed in conjunction with jet pump, the lift capacity of jet pump can be increased greatly; (4) With water jets, the air lift can improve the fragmentation radius and capacity. The main factors that affect the effect of water jet are the submergible status of jet, jet pressure, and flowrate. The ideal jet of the monitor in the borehole hydraulic coal-mining system is a nonsubmergible free jet. Through air lift, the nonsubmergible free jet can be set up in the mining hole.

  4. Laboratory Simulations of Hydraulic Fracturing

    Microsoft Academic Search

    J. M. Papadopoulos; V. M. Narendran; M. P. Cleary

    1983-01-01

    Two novel distinctly different laboratory apparatus have been developed to allow controlled, precise, repeatable and observable experimental simulations of hydraulic fracturing over a broad range of well-determined dominant parameters and practical geometries. One system avoids specimen preparation (by using predetermined interface separation), while the other most efficiently employs castable blocks with proper scaling of fracture toughness to correctly capture crack

  5. Containment of massive hydraulic fractures

    Microsoft Academic Search

    E. R. Simonson; A. S. Abou-Sayed; R. J. Clifton

    1976-01-01

    Hydraulic fracture containment is discussed from the point of view of linear elastic fracture mechanics. Three cases are analyzed: (a) Effect of different material properties for the pay zone and the barrier formation, (b) Characteristic of fracture propagation into region of varying in situ stress and (c) Effect of hydrostatic pressure gradients on fracture propagation into overlying or underlying barrier

  6. Hydraulic Fracture Containment in Sand

    Microsoft Academic Search

    Y. Dong

    2010-01-01

    The mechanism of hydraulic fracturing in soft, high permeability material is considered fundamentally different from that in hard, low permeability rock, where a tensile fracture is created and conventional linear elastic fracture mechanics (LEFM) applies. The fracturing and associated modeling work is then a relatively new area. Particularly, the fracture containment in layered formations remains unknown. This research is aiming

  7. Hydro Hydraulics - a disappearing art?

    Microsoft Academic Search

    J. L. Gordon

    2007-01-01

    Over the past decade, there have been several instances where the performance of new hydro developments has been compromised by unsatisfactory operation of some component associated with the hydraulic design of the facility. This paper will outline the types of deficiencies encountered, and suggest some remedies. The incidents include - gravel entrainment at intakes; \\

  8. Life testing hydraulic gear motors

    Microsoft Academic Search

    James A McLinn

    2005-01-01

    A hydraulic gear motor for pump oil may be run as a component in an endurance type of accelerated life test (ALT) with several different applied stresses. The main failure modes may be first established and the life test developed based upon the failure modes. The purpose of an accelerated test is to demonstrate a minimum life in a simulated

  9. Reducing leaks in hydraulic systems

    SciTech Connect

    Simko, D.M. [Swagelok Co., Solon, OH (United States)

    1995-07-10

    This article examines the effect of hydraulic system leaks on energy efficiency and cost. The topics of the article include causes of leakage, external and internal leakage, safety hazards, simple seals and sealants for tapered pipe threads, maintaining, retrofitting, or reworking welded systems, and lowering leakage by reducing the number of fittings.

  10. Introduction to Hydraulics. Student's Manual.

    ERIC Educational Resources Information Center

    Texas Univ., Austin. Extension Instruction and Materials Center.

    This manual on hydraulics is one of a series of individualized instructional materials for students. The manual is self-paced, but is designed to be used under the supervision of an instructor. The manual contains 10 assignments, each with all the information needed, a list of objectives that should be met, and exercise questions that can help in…

  11. Introduction to Hydraulics. Instructor's Guide.

    ERIC Educational Resources Information Center

    Texas Univ., Austin. Extension Instruction and Materials Center.

    This instructor's guide on hydraulics is part of a series of individualized instructional materials. The guide is provided to help the instructor make certain that each student gets the most benefit possible from both the student's manual and what he/she does on the job. Notes for the instructor contain suggestions on how the student should use…

  12. Thermal-Hydraulic-Analysis Program

    NASA Technical Reports Server (NTRS)

    Walton, J. T.

    1993-01-01

    ELM computer program is simple computational tool for modeling steady-state thermal hydraulics of flows of propellants through fuel-element-coolant channels in nuclear thermal rockets. Evaluates various heat-transfer-coefficient and friction-factor correlations available for turbulent pipe flow with addition of heat. Comparisons possible within one program. Machine-independent program written in FORTRAN 77.

  13. Flow Distribution in Hydraulic Systems

    NASA Technical Reports Server (NTRS)

    Nguyen, S. N.

    1983-01-01

    General Flow Distribution Program analyzes pressure drops and flow distribution in closed and open hydraulic systems. Analyzes system on basis of incompressible flow though system may contain either compressible or incompressible fluid. Program solves fixed or variable flow problems for series, parallel, or series/parallel systems.

  14. Manual or hydraulic gearshifting apparatus

    SciTech Connect

    Ishida, H.; Kojima, Y.

    1986-04-08

    A vehicle transmission control apparatus is described which consists of: a plurality of shift members for operating a vehicle transmission; a lever adapted for linear movement into a plurality of positions, one each of the lever being operatively coupled to a different one of the shift members in each of the positions; the lever being further adapted for pivotal movement in response to which the one end of the lever actuates the operatively coupled shift member; a select actuator means comprising a select hydraulic cylinder and a select piston retained thereby, the select piston being coupled to the lever and hydraulically controlled to produce the linear movement thereof; a shift actuator means comprising a shift hydraulic cylinder and a shift piston retained thereby, the shift piston being coupled to the lever and hydraulically controlled to produce the pivotal movement thereof; a casing means retaining the lever, the select actuator means, and the shift actuator means; and a control member comprising a portion within the casing means and coupled to the lever and a manually accessible portion always disposed outside the casing means and having means adapted for manual actuation to produce either the linear or the pivotal movement of the lever.

  15. Hierarchical Control Strategy for a Hybrid Hydro-mechanical Transmission (HMT) Power-Train

    E-print Network

    Li, Perry Y.

    Fluid Power (CCEFP) as a test-bed for hydraulic system and components research. The CCEFP hydraulic Cheong, Zhekang Du, Perry Y. Li and Thomas R. Chase Abstract-- A hydraulic hybrid passenger vehicle using and the efficiency is dependent on the energy management used. I. INTRODUCTION Hydraulic hybrid vehicles reduce fuel

  16. Pair correlation function characteristics of nearly jammed disordered and ordered hard-sphere packings

    NASA Astrophysics Data System (ADS)

    Donev, Aleksandar; Torquato, Salvatore; Stillinger, Frank H.

    2005-01-01

    We study the approach to jamming in hard-sphere packings and, in particular, the pair correlation function g2(r) around contact, both theoretically and computationally. Our computational data unambiguously separate the narrowing ? -function contribution to g2 due to emerging interparticle contacts from the background contribution due to near contacts. The data also show with unprecedented accuracy that disordered hard-sphere packings are strictly isostatic: i.e., the number of exact contacts in the jamming limit is exactly equal to the number of degrees of freedom, once rattlers are removed. For such isostatic packings, we derive a theoretical connection between the probability distribution of interparticle forces Pf(f) , which we measure computationally, and the contact contribution to g2 . We verify this relation for computationally generated isostatic packings that are representative of the maximally random jammed state. We clearly observe a maximum in Pf and a nonzero probability of zero force, shedding light on long-standing questions in the granular-media literature. We computationally observe an unusual power-law divergence in the near-contact contribution to g2 , persistent even in the jamming limit, with exponent -0.4 clearly distinguishable from previously proposed inverse-square-root divergence. Additionally, we present high-quality numerical data on the two discontinuities in the split-second peak of g2 and use a shared-neighbor analysis of the graph representing the contact network to study the local particle clusters responsible for the peculiar features. Finally, we present the computational data on the contact contribution to g2 for vacancy-diluted fcc crystal packings and also investigate partially crystallized packings along the transition from maximally disordered to fully ordered packings. We find that the contact network remains isostatic even when ordering is present. Unlike previous studies, we find that ordering has a significant impact on the shape of Pf for small forces.

  17. Development of the Packed Bed Reactor ISS Flight Experiment

    NASA Technical Reports Server (NTRS)

    Patton, Martin O.; Bruzas, Anthony E.; Rame, Enrique; Motil, Brian J.

    2012-01-01

    Packed bed reactors are compact, require minimum power and maintenance to operate, and are highly reliable. These features make this technology a leading candidate as a potential unit operation in support of long duration human space exploration. On earth, this type of reactor accounts for approximately 80% of all the reactors used in the chemical process industry today. Development of this technology for space exploration is truly crosscutting with many other potential applications (e.g., in-situ chemical processing of planetary materials and transport of nutrients through soil). NASA is developing an ISS experiment to address this technology with particular focus on water reclamation and air revitalization. Earlier research and development efforts funded by NASA have resulted in two hydrodynamic models which require validation with appropriate instrumentation in an extended microgravity environment. The first model developed by Motil et al., (2003) is based on a modified Ergun equation. This model was demonstrated at moderate gas and liquid flow rates, but extension to the lower flow rates expected in many advanced life support systems must be validated. The other model, developed by Guo et al., (2004) is based on Darcy s (1856) law for two-phase flow. This model has been validated for a narrow range of flow parameters indirectly (without full instrumentation) and included test points where the flow was not fully developed. The flight experiment presented will be designed with removable test sections to test the hydrodynamic models. The experiment will provide flexibility to test additional beds with different types of packing in the future. One initial test bed is based on the VRA (Volatile Removal Assembly), a packed bed reactor currently on ISS whose behavior in micro-gravity is not fully understood. Improving the performance of this system through an accurate model will increase our ability to purify water in the space environment.

  18. 25 kWe solar thermal stirling hydraulic engine system: Final conceptual design report

    SciTech Connect

    Not Available

    1988-01-01

    This report documents the conceptual design and analysis of a solar thermal free-piston Stirling hydraulic engine system designed to deliver 25 kWe when coupled to the 11-meter Test Bed Concentrator at Sandia National Laboratories. A manufacturing cost assessment for 10,000 units per year was made by Pioneer Engineering and Manufacturing. The design meets all program objectives including a 60,000-hr design life, dynamic balancing, fully automated control, >33.3% overall system efficiency, properly conditioned power, maximum utilization of annualized insolation, and projected production costs of $300/kW. The system incorporates a simple, rugged, reliable pool boiler reflux heat pipe to transfer heat from the solar receiver to the Stirling engine. The free-piston engine produces high-pressure hydraulic flow which powers a commercial hydraulic motor that, in turn, drives a commercial rotary induction generator. The Stirling hydraulic engine uses hermetic bellows seals to separate helium working gas from hydraulic fluid which provides hydrodynamic lubrication to all moving parts. Maximum utilization of highly refined, field proven commercial components for electric power generation minimizes development cost and risk. The engine design is based on a highly refined Stirling hydraulic engine developed over 20 years as a fully implantable artificial heart power source. 4 refs., 19 figs., 3 tabs.

  19. Novel press pack IGBT device and switch assembly for Pulse Modulators

    Microsoft Academic Search

    Philip Bill; Adriaan Welleman; Esie Ramezani; Soto Gekenidis; Reto Leutwyler

    2011-01-01

    As the trend for Pulse Modulator applications nowadays is moving strongly into the direction of switch-on\\/-off devices, ABB has developed a new IGBT module which is designed to operate under specific pulsed power, non industrial standard conditions. A press pack IGBT module will be presented which is optimized for pulsed power applications. The device has a collector-emitter voltage Vces of

  20. Six-pack IGBT dynamic electro-thermal model: parameter extraction and validation

    Microsoft Academic Search

    J. Reichl; D. Berning; A. Hefner; J.-S. Lai

    2004-01-01

    An electro-thermal simulation model is developed for a six-pack IGBT power module. A measurement system suitable for extracting transient thermal data for short term, high-power heating conditions is used in this work for thermal model validation. A set of parameter extraction software tools is used to extract the electrical parameters as well as temperature dependent parameters associated with the IGBT

  1. Vertical fracture containment during massive hydraulic fracturing

    SciTech Connect

    Cormack, D.E.; Fung, R.L.; Vijayakumar, S.

    1983-01-01

    Massive hydraulic fractures are projected to play a major role in the recovery of the tremendous reserves of gas tied up in the tight gas sands of the Deep Basin of N. Alberta and British Columbia. One of the major problems in designing fractures in such formations is the uncertain vertical extent of these fractures: fracture containment. This work presents a procedure for predicting the vertical extent of fractures in multi-layered formations with varying material properties and tectonic stresses. The numeric procedure uses the finite element technique for the rock deformation calculations and employs special high order, crack-tip elements to improve the accuracy of stress intensity calculations. Furthermore, it makes use of the powerful numeric technique of static condensation to reduce computer memory and computation time. The elastic deformation calculation can be coupled to a fluid flow model to predict dynamic fracture growth.

  2. Dense Packings of Polyhedra: Platonic and Archimedean Solids

    E-print Network

    S. Torquato; Y. Jiao

    2009-09-09

    We formulate the problem of generating dense packings of nonoverlapping, non-tiling polyhedra within an adaptive fundamental cell subject to periodic boundary conditions as an optimization problem, which we call the Adaptive Shrinking Cell (ASC) scheme. This novel optimization problem is solved here (using a variety of multi-particle initial configurations) to find the dense packings of each of the Platonic solids in three-dimensional Euclidean space R3 , except for the cube, which is the only Platonic solid that tiles space. We find the densest known packings of tetrahedra, icosahedra, dodecahedra, and octahedra with densities 0.823, 0.836, 0.904, and 0.947, respectively. It is noteworthy that the densest tetrahedral packing possesses no long-range order. Unlike the densest tetrahedral packing, which must not be a Bravais lattice packing, the densest packings of the other non-tiling Platonic solids that we obtain are their previously known optimal (Bravais) lattice packings. We also derive a simple upper bound on the maximal density of packings of congruent nonspherical particles, and apply it to Platonic solids, Archimedean solids, superballs and ellipsoids. Our simulation results, rigorous upper bounds, and other theoretical arguments lead us to the conjecture that the densest packings of Platonic and Archimedean solids with central symmetry are given by their corresponding densest lattice packings. In addition, we conjecture that the optimal packing of any convex, congruent polyhedron without central symmetry generally is not a lattice packing.

  3. Bucking the pack ice to Prudhoe Bay

    Microsoft Academic Search

    Kizzia

    1976-01-01

    Forty-seven giant barges with a billion dollars worth of freight for the Alaska pipeline had been waiting since July 4, 1975 to proceed on through the ice to make the 300-mile run to Prudhoe Bay. Normally, easterly summer winds blow the pack ice into the Chukchi Sea where wave action breaks it up, leaving a broad highway of open water

  4. Covering and packing pumpkin models Dimitris Chatzidimitriou

    E-print Network

    Dimitrios, Thilikos

    Covering and packing pumpkin models Dimitris Chatzidimitriou Jean-Florent Raymond Ignasi Sau§ Dimitrios M. Thilikos§ Abstract Let r (the r-pumpkin) be the multi-graph containing two vertices and r. This graph is also known as the r-pumpkin and is denoted by r. In [7], Fiorini, Joret, and Sau proved

  5. Radiological and practical aspects of body packing

    PubMed Central

    Reginelli, A; Pinto, F; Sica, G; Scaglione, M; Berger, F H; Romano, L; Brunese, L

    2014-01-01

    Body packing represents the concealment of illegal substances in a person's body with the aim of smuggling. “Body packers” either swallow drug-filled packets or introduce drug-filled packets into their bodies rectally or vaginally with the purpose of concealing them. The three main smuggled drugs are cocaine, heroin and cannabis products. Body packing represents a serious risk of acute narcotic toxicity from drug exposure, intestinal obstruction owing to pellet impaction and bowel perforation with consequent abdominal sepsis. A suspected body packer is generally admitted to hospital to perform imaging investigations and confirm the presence of drugs in his/her body. Radiological imaging methods are essential to diagnose body packing and to detect potential complications. Increasing sophistication of traffickers and improvements in packaging add to the detection difficulty. Radiologists should be aware of the appearance of drug packets in a range of imaging modalities. This article informs physicians about the challenging aspects of body packing, its background and medicolegal issues, what imaging methods can be used and what criteria are necessary to perform a correct diagnosis. PMID:24472727

  6. 7 CFR 51.3152 - Standard pack.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...Nectarines packed in containers equipped with cell compartments, cardboard fillers or molded trays shall be of the proper size for the cells, fillers, or molds in which they are...measured at right angles to a line from stem to blossom end of the fruit....

  7. 7 CFR 51.2338 - Standard pack.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... (1) Fruit packed in containers with cell compartments, cardboard fillers or molded trays shall be of proper size for the cells, fillers, or molds in which they are...measured at right angles to a line from stem to blossom end. (f) In order...

  8. 7 CFR 51.3152 - Standard pack.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...Nectarines packed in containers equipped with cell compartments, cardboard fillers or molded trays shall be of the proper size for the cells, fillers, or molds in which they are...measured at right angles to a line from stem to blossom end of the fruit....

  9. 7 CFR 51.2338 - Standard pack.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... (1) Fruit packed in containers with cell compartments, cardboard fillers or molded trays shall be of proper size for the cells, fillers, or molds in which they are...measured at right angles to a line from stem to blossom end. (f) In order...

  10. 7 CFR 51.2338 - Standard pack.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... (1) Fruit packed in containers with cell compartments, cardboard fillers or molded trays shall be of proper size for the cells, fillers, or molds in which they are...measured at right angles to a line from stem to blossom end. (f) In order...

  11. 7 CFR 51.3152 - Standard pack.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...Nectarines packed in containers equipped with cell compartments, cardboard fillers or molded trays shall be of the proper size for the cells, fillers, or molds in which they are...measured at right angles to a line from stem to blossom end of the fruit....

  12. Leadership in Wolf, Canis lupus, Packs

    NSDL National Science Digital Library

    Mech, L. David.

    The Northern Prairie Wildlife Research Center (NPWRC) continues to place scientific/ management resources online for general viewing. L. David Mech recently published this article in Canadian Field-Naturalist [114(2):259-263, 2000] describing leadership in wolf packs. It may be browsed online or downloaded as a .zip file.

  13. An algorithm for packing connectors J. Keijsper

    E-print Network

    Keijsper, Judith

    An algorithm for packing connectors J. Keijsper University of Amsterdam Department of MathematicsS; Tg of V , an S--T connector is a set of edges F ` E such that every component of the subgraph (V; F ) intersects both S and T . If either S or T is a singleton, then an S--T connector is a spanning subgraph of G

  14. Hear Your Heart ClassPack

    NSDL National Science Digital Library

    2010-04-22

    Using More Picture-Perfect Science Lessons: Using Children's Books to Guide Inquiry, K-4 in your classroom is easier than ever! NSTA's ClassPacks, each sufficient for a class of 28 students, are lesson-specific collections of materials--an unmatche

  15. Computer simulation of interfacial packing in concrete

    Microsoft Academic Search

    M. W. Grutzeck; D. Shi; G. Liu; S. Kwan

    1993-01-01

    Computer simulation of particle packing against an aggregate surface was undertaken to show the effects of four variables on interfacial porosity profiles. The variables in order of significance and their assumed physical meaning are: sticking probability (tendency of cement particles to flocculate), amplitude of particle motion (energy of mixing), travel distance of particle to surface (thickness of water film surrounding

  16. Assessment of packing characteristics by computer simulation

    Microsoft Academic Search

    Piet Stroeven; Martijn Stroeven

    1999-01-01

    Most relevant engineering mechanical properties of normal concretes such as compressive strength are to a large extent governed by the density and the uniformity of the aggregate packing as the load-bearing structure. Nevertheless, the integrity of this skeleton will gradually break down under increased loadings. In cementitious materials this is due to debonding of particle-matrix interfaces, which leads to crack

  17. Characteristics of Stratified Bedded Pack Dairy Manure

    Technology Transfer Automated Retrieval System (TEKTRAN)

    "Compost" dairy barns are a relatively new housing system that generates a deep (0.9 to 1.5 m), stratified bedded pack (SBP) manure source. Bedding composed of sawdust, wood chips, or crop residues accumulates as additions are made to maintain a dry surface. Surface drying is promoted by a combinati...

  18. Simple cloud chambers using gel ice packs

    Microsoft Academic Search

    Masahiro Kamata; Miki Kubota

    2012-01-01

    Although cloud chambers are highly regarded as teaching aids for radiation education, school teachers have difficulty in using cloud chambers because they have to prepare dry ice or liquid nitrogen before the experiment. We developed a very simple and inexpensive cloud chamber that uses the contents of gel ice packs which can substitute for dry ice or liquid nitrogen. The

  19. Inertness of Bonded Silica Gel Packings

    Microsoft Academic Search

    M. Ohhira; F. Ohmura; T. Hanai

    1989-01-01

    Stability and inertness of bonded silica gel packings were examined from the retention behavior of acidic and basic compounds, and also metal sensitive compounds. Bonded silica gels made from pure silica gel were stable in acidic and basic solutions, and did not interfere with chromatography of chelate reagents in reversed-phase liquid chromatography.

  20. Packing, tiling, and covering with tetrahedra

    Microsoft Academic Search

    J. H. Conway; S. Torquato

    2006-01-01

    It is well known that three-dimensional Euclidean space cannot be tiled by regular tetrahedra. But how well can we do? In this work, we give several constructions that may answer the various senses of this question. In so doing, we provide some solutions to packing, tiling, and covering problems of tetrahedra. Our results suggest that the regular tetrahedron may not

  1. Optimal packing using the multiple mating method

    Microsoft Academic Search

    Chan Yu; Souran Manoochehri

    2003-01-01

    A new method for the solution of the packing problem is presented. The method introduces a mating concept to the problem. The mating allows one or more objects to be positioned relative to the other by applying mating conditions that are derived from the geometric features among them. Once mated, objects within a mating pair or a mating group are

  2. Simple Cloud Chambers Using Gel Ice Packs

    ERIC Educational Resources Information Center

    Kamata, Masahiro; Kubota, Miki

    2012-01-01

    Although cloud chambers are highly regarded as teaching aids for radiation education, school teachers have difficulty in using cloud chambers because they have to prepare dry ice or liquid nitrogen before the experiment. We developed a very simple and inexpensive cloud chamber that uses the contents of gel ice packs which can substitute for dry…

  3. 7 CFR 51.1005 - Standard pack.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...container may vary more than four-sixteenths of an inch in diameter. (d) In order to allow for variations, other than sizing, incident to proper packing, not more than 5 percent of the packages in any lot may fail to meet the requirements of...

  4. 7 CFR 51.630 - Standard Pack.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...27 size and larger—not more than nine-sixteenths inch in diameter. (d) In order to allow for variations, other than sizing, incident to proper packing, not more than 5 percent of the packages in any lot may fail to meet the requirements of...

  5. 7 CFR 51.630 - Standard Pack.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...27 size and larger—not more than nine-sixteenths inch in diameter. (d) In order to allow for variations, other than sizing, incident to proper packing, not more than 5 percent of the packages in any lot may fail to meet the requirements of...

  6. 7 CFR 51.630 - Standard Pack.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...27 size and larger—not more than nine-sixteenths inch in diameter. (d) In order to allow for variations, other than sizing, incident to proper packing, not more than 5 percent of the packages in any lot may fail to meet the requirements of...

  7. 7 CFR 51.1005 - Standard pack.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...container may vary more than four-sixteenths of an inch in diameter. (d) In order to allow for variations, other than sizing, incident to proper packing, not more than 5 percent of the packages in any lot may fail to meet the requirements of...

  8. 7 CFR 51.630 - Standard Pack.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...27 size and larger—not more than nine-sixteenths inch in diameter. (d) In order to allow for variations, other than sizing, incident to proper packing, not more than 5 percent of the packages in any lot may fail to meet the requirements of...

  9. 7 CFR 51.1005 - Standard pack.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...container may vary more than four-sixteenths of an inch in diameter. (d) In order to allow for variations, other than sizing, incident to proper packing, not more than 5 percent of the packages in any lot may fail to meet the requirements of...

  10. 7 CFR 51.3055 - Standard pack.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...the container. Size of the avocados may be specified by count. (b) In order to allow for variations incident to proper sizing and packing, not more than 5 percent, by count, of the avocados in any container may weigh less than 75 percent of the...

  11. 7 CFR 51.1005 - Standard pack.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...container may vary more than four-sixteenths of an inch in diameter. (d) In order to allow for variations, other than sizing, incident to proper packing, not more than 5 percent of the packages in any lot may fail to meet the requirements of...

  12. 7 CFR 51.630 - Standard Pack.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...27 size and larger—not more than nine-sixteenths inch in diameter. (d) In order to allow for variations, other than sizing, incident to proper packing, not more than 5 percent of the packages in any lot may fail to meet the requirements of...

  13. Thermal Hydraulic Analysis of HTGR Coupled with Hydrogen Plant

    SciTech Connect

    Chang Oh; Cliff Davis; Robert Barner; Paul Pickard

    2006-06-01

    The US Department of Energy is investigating the use of high-temperature gas-cooled reactors (HTGR) to produce electricity and hydrogen. Although the hydrogen production processes using the nuclear energy are in an early stage of development, coupling hydrogen plant to HTGR requires both efficient heat transfer and adequate separation of the facilities to assure that off-normal events in the production facility do not impact the nuclear plant. In anticipation of the design, development and procurement of an advanced power conversion system for HTGR, this study was initiated to identify the major design and technology options and their tradeoffs in the evaluation of power conversion system (PCS) coupled to hydrogen plant. In this study, we investigated a number of design configurations and performed thermal hydraulic analyses using various working fluids and various conditions. This paper includes a portion of thermal hydraulic results based on a direct cycle and a parallel intermediate heat exchanger (IHX) configuration option.

  14. Barrier properties of k-mer packings

    NASA Astrophysics Data System (ADS)

    Lebovka, N.; Khrapatiy, S.; Vygornitskyi; Pivovarova, N.

    2014-08-01

    This work discusses numerical studies of the barrier properties of k-mer packings by the Monte Carlo method. The studied variants of regular and non-regular arrangements on a square lattice included models of random sequential adsorption (RSA) and random deposition (RD). The discrete problem of diffusion through the bonds of a square lattice was considered. The k-mers were perfectly oriented perpendicular to the diffusion direction and blocked certain fraction of bonds fb against diffusion. The barrier efficiency was estimated by calculation of the ratio D/Do where D is diffusion coefficient in direction perpendicular to the orientation of k-mers and Do is the same value for diffusion on the square lattice without blocked bonds, i.e., at fb=0. The value of k varied from 1 to 512 and different lattice sizes up to L=8192 lattice units were used. For dense packings (p=1), the obtained D/Do versus fb dependences deviated from the theoretical prediction of effective medium (EM) theory and deviation was the most obvious for the regular non-staggered arrangement. For loose RSA and RD packings, the percolation like-behavior of D/Do with threshold at fb=p? was observed and the data evidenced that their barrier properties at large values of k may be more effective than those of some dense packings. Such anomalous behavior can reflect the details of k-mer spatial organization (aggregation) and structure of pores in RD and RSA packings. The contradictions between simulation data and predictions of EM theory were also discussed.

  15. Transitive Packing: A Unifying Concept in Combinatorial Optimization

    E-print Network

    Schulz, Andreas S.

    This paper attempts to give a better understanding of the facial structure of previously separately investigated polyhedra. It introduces the notion of transitive packing and the transitive packing polytope. Polytopes that ...

  16. 36 CFR 34.10 - Saddle and pack animals.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...animals. 34.10 Section 34.10 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR EL PORTAL ADMINISTRATIVE SITE REGULATIONS § 34.10 Saddle and pack animals. The use of saddle and pack animals is...

  17. Energy Saving in Distillation Using Structured Packing and Vapor Recompression

    E-print Network

    Hill, J.H.

    "Distillation is a big consumer of energy in process plant operations. A first step to energy cost savings is the use of high efficiency structured packing in place of trays or dumped packings in conventionally operated distillation columns. Larger...

  18. 7 CFR 51.2840 - Export packing requirements.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...CERTIFICATION, AND STANDARDS) United States Standards for Grades of Onions (Other Than Bermuda-Granex-Grano and Creole Types) Export...Requirements § 51.2840 Export packing requirements. Onions specified as meeting Export Packing Requirements shall...

  19. 7 CFR 51.2840 - Export packing requirements.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...CERTIFICATION, AND STANDARDS) United States Standards for Grades of Onions (Other Than Bermuda-Granex-Grano and Creole Types) Export...Requirements § 51.2840 Export packing requirements. Onions specified as meeting Export Packing Requirements shall be...

  20. 7 CFR 51.2840 - Export packing requirements.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...CERTIFICATION, AND STANDARDS) United States Standards for Grades of Onions (Other Than Bermuda-Granex-Grano and Creole Types) Export...Requirements § 51.2840 Export packing requirements. Onions specified as meeting Export Packing Requirements shall be...

  1. 27 CFR 24.308 - Bottled or packed wine record.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...2010-04-01 false Bottled or packed wine record. 24.308 Section 24.308 ...BUREAU, DEPARTMENT OF THE TREASURY LIQUORS WINE Records and Reports § 24.308 Bottled or packed wine record. A proprietor who bottles,...

  2. 27 CFR 24.255 - Bottling or packing wine.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 2010-04-01 false Bottling or packing wine. 24.255 Section 24.255 Alcohol...BUREAU, DEPARTMENT OF THE TREASURY LIQUORS WINE Storage, Treatment and Finishing of Wine Bottling, Packing, and Labeling of Wine...

  3. Pump tests for hydraulic fluid wear qualification

    SciTech Connect

    Tessmann, R.K.; Heer, D.J. [FES, Inc., Stillwater, OK (United States)

    1997-12-31

    Modern hydraulic systems are operating at higher pressures and higher temperatures than ever before. In addition, the life and reliability of the hydraulic components and hence the hydraulic system is becoming more and more dependent upon the characteristics of the circulating fluid in the system. The hydraulic component which normally suffers most when the correct fluid is not used in the system is the hydraulic pump. Three different types of hydraulic pumps are widely used in hydraulic systems. Vane pumps have been the dominant type of pump for hydraulic systems. Gear pumps have replaced vane pumps in many applications. Piston pumps are rapidly gaining popularity. Therefore, the pump manufacturers are conducting tests to qualify fluids for use with their pumps and the fluids formulators are conducting tests to show that their formulations are compatible with hydraulic components. Unfortunately, the tests most widely used are either no industry standards or do not address problems encountered with some hydraulic pumps. This paper presents an overview of the pump tests which are currently available or which are specific to certain hydraulic pumps. Since there are few standard pump tests, many companies have devised their own tests to be confident of the fluids which they qualify. Additional concepts in pump testing are proposed and discussed.

  4. Frictionless bead packs have macroscopic friction, but no dilatancy

    NASA Astrophysics Data System (ADS)

    Peyneau, Pierre-Emmanuel; Roux, Jean-Noël

    2008-07-01

    The statement of the title is shown by numerical simulation of homogeneously sheared assemblies of frictionless, nearly rigid beads in the quasistatic limit. Results coincide for steady flows at constant shear rate ?? in the limit of small ?? and static approaches, in which packings are equilibrated under growing deviator stresses. The internal friction angle ? , equal to 5.76°±0.22° in simple shear, is independent of average pressure P in the rigid limit and stems from the ability of stable frictionless contact networks to form stress-induced anisotropic fabrics. No enduring strain localization is observed. Dissipation at the macroscopic level results from repeated network rearrangements, similar to the effective friction of a frictionless slider on a bumpy surface. Solid fraction ? remains equal to the random close packing value ?0.64 in slowly or statically sheared systems. Fluctuations of stresses and volume are observed to regress in the large system limit. Defining the inertial number as I=??m/(aP) , with m the grain mass and a its diameter, both internal friction coefficient ??=tan? and volume 1/? increase as powers of I in the quasistatic limit of vanishing I , in which all mechanical properties are determined by contact network geometry. The microstructure of the sheared material is characterized with a suitable parametrization of the fabric tensor and measurements of coordination numbers.

  5. Velocity dependence of cavitation shock pressures in a hydraulic turbomachinery

    Microsoft Academic Search

    R. Oba; Y. Ito; J. Higuchi; K. T. Kim

    1979-01-01

    The cavitation aspects as well as the shock pressures are accurately analyzed in a high-speed hydraulic turbomachinery for various hydrodynamic quantities as a first step to clarify the mechanism for cavitation erosion, especially the velocity dependence. As the flow velocity V(R) is increased, the shock pressures greatly increase with the n-th power of V(R) in the lower speed range of

  6. Coupled neutronics\\/thermal–hydraulics analysis of CANDU–SCWR fuel channel

    Microsoft Academic Search

    Jianqiang Shan; Wei Chen; Bo Wook Rhee; Laurence K. H. Leung

    2010-01-01

    At supercritical pressure condition, the thermal–hydraulics behavior of water differs strongly from that at sub-critical pressure due to a rapid variation of the thermal–physical properties across the pseudo-critical line. A coupling analysis of neutronics and thermal–hydraulics has become important for SCWR, because of the strong link between the water density and the neutron spectrum and subsequently the power distribution. The

  7. Packing Algorithms for Arborescences (and Spanning Trees) in Capacitated Graphs

    Microsoft Academic Search

    Harold N. Gabow; K. S. Manu

    1995-01-01

    In a digraph with real-valued edge capacities, we pack the greatest number of arborescences in time O(n\\u000a3\\u000am log (n\\u000a2\\/m)); the packing uses at most m distinct arborescences. Here n and m denote the number of vertices and edges respectively. Similar results hold for integral packing: we pack the greatest number of arborescences in time O(minn, log (nN)n

  8. Disordered, Quasicrystalline and Crystalline Phases of Densely Packed Tetrahedra

    Microsoft Academic Search

    Amir Haji-Akbari; Michael Engel; Aaron S. Keys; Xiaoyu Zheng; Rolfe G. Petschek; Peter Palffy-Muhoray; Sharon C. Glotzer

    2010-01-01

    All hard, convex shapes are conjectured by Ulam to pack more densely than\\u000aspheres, which have a maximum packing fraction of {\\\\phi} = {\\\\pi}\\/\\\\sqrt18 ~\\u000a0.7405. For many shapes, simple lattice packings easily surpass this packing\\u000afraction. For regular tetrahedra, this conjecture was shown to be true only\\u000avery recently; an ordered arrangement was obtained via geometric construction\\u000awith {\\\\phi}

  9. Disordered, quasicrystalline and crystalline phases of densely packed tetrahedra

    Microsoft Academic Search

    Amir Haji-Akbari; Michael Engel; Aaron S. Keys; Xiaoyu Zheng; Rolfe G. Petschek; Peter Palffy-Muhoray; Sharon C. Glotzer

    2009-01-01

    All hard, convex shapes are conjectured by Ulam to pack more densely than spheres, which have a maximum packing fraction of phi = pi\\/&surd;18~0.7405. Simple lattice packings of many shapes easily surpass this packing fraction. For regular tetrahedra, this conjecture was shown to be true only very recently; an ordered arrangement was obtained via geometric construction with phi = 0.7786

  10. Consumer perceptions of bonus packs: an exploratory analysis

    Microsoft Academic Search

    Beng Soo Ong; Foo Nin Ho; Carolyn Tripp

    1997-01-01

    Presents an account of a study which examined consumer perceptions of bonus pack offers. A bonus pack is a manufacturer’s sales promotion technique of giving the buyer an extra quantity of a product at the usual price (e.g. an extra 6 oz free; buy four, get one free). No scholarly research on bonus packs was uncovered by the literature review.

  11. Solving Bin Packing Related Problems Using an Arc Flow Formulation

    E-print Network

    Filipe Brandão

    2012-04-13

    Apr 13, 2012 ... Solving Bin Packing Related Problems Using an Arc Flow Formulation ... cutting stock, cardinality constrained bin packing, and 2D-vector bin packing. ... a large advantage of this formulation with respect to the traditional ones. ... Category 2: Applications -- OR and Management Sciences (Transportation ).

  12. 21 CFR 890.5730 - Moist heat pack.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...2011-04-01 2011-04-01 false Moist heat pack. 890.5730 Section 890.5730 Food...Medicine Therapeutic Devices § 890.5730 Moist heat pack. (a) Identification. A moist heat pack is a device intended for medical...

  13. 21 CFR 890.5730 - Moist heat pack.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...2010-04-01 2010-04-01 false Moist heat pack. 890.5730 Section 890.5730 Food...Medicine Therapeutic Devices § 890.5730 Moist heat pack. (a) Identification. A moist heat pack is a device intended for medical...

  14. Relating protein conformational changes to packing efficiency and disorder

    E-print Network

    Gerstein, Mark

    Relating protein conformational changes to packing efficiency and disorder Nitin Bhardwaj1 and Mark, Connecticut 06520 3 Department of Computer Science, Yale University, New Haven, Connecticut 06520 Received 10 in relation to two key structural metrics: packing efficiency and disorder. Packing has been shown

  15. On online bin packing with LIB constraints Leah Epstein

    E-print Network

    Epstein, Leah

    On online bin packing with LIB constraints Leah Epstein Abstract In many applications of packing with LIB (Larger Item in the Bottom) constraints. We give an improved analysis of First Fit showing(I) . In the online bin packing problem with LIB (Larger Item in the Bottom) constraints [9, 10, 4, 11], the sub

  16. Mass transfer in aqueous two-phases system packed column

    Microsoft Academic Search

    L Igarashi; T. G Kieckbusch; T. T Franco

    2004-01-01

    The behavior of xylanase extraction in a packed column using polyethylene glycol (PEG) 4000 and dipotassium phosphate was studied. The possibility of using the packed column in continuous operations for enzyme extraction was studied since the previous work had only addressed the semi-continuous extraction of enzyme. The influence of several kinds of packings, Raschig rings, glass spheres and polystyrene rings

  17. Exhaustive approaches to 2D rectangular perfect packings

    Microsoft Academic Search

    Neal Lesh; Joe Marks; A. Mcmahon; Michael Mitzenmacher

    2004-01-01

    In this paper, we consider the two-dimensional rectangular strip packing problem, in the case where there is a perfect packing; that is, there is no wasted space. One can think of the problem as a jigsaw puzzle with oriented rectangular pieces. Although this comprises a quite special case for strip packing, we have found it useful as a subroutine in

  18. Disordered, quasicrystalline and crystalline phases of densely packed tetrahedra

    E-print Network

    Palffy-Muhoray, Peter

    LETTERS Disordered, quasicrystalline and crystalline phases of densely packed tetrahedra Amir Haji easily surpass this packing fraction2,3 . For regular tetrahedra, this conjec- ture was shown to be true with different initial condi- tions led to w 5 0.8230 (ref. 6). Here we show that tetrahedra pack evenmoredensely

  19. 21 CFR 890.5710 - Hot or cold disposable pack.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 2010-04-01 2010-04-01 false Hot or cold disposable pack. 890.5710 Section...Medicine Therapeutic Devices § 890.5710 Hot or cold disposable pack. (a) Identification. A hot or cold disposable pack is a device...

  20. 21 CFR 890.5710 - Hot or cold disposable pack.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 2013-04-01 2013-04-01 false Hot or cold disposable pack. 890.5710 Section...Medicine Therapeutic Devices § 890.5710 Hot or cold disposable pack. (a) Identification. A hot or cold disposable pack is a device...

  1. 21 CFR 890.5710 - Hot or cold disposable pack.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 2011-04-01 2011-04-01 false Hot or cold disposable pack. 890.5710 Section...Medicine Therapeutic Devices § 890.5710 Hot or cold disposable pack. (a) Identification. A hot or cold disposable pack is a device...

  2. 21 CFR 890.5710 - Hot or cold disposable pack.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 2012-04-01 2012-04-01 false Hot or cold disposable pack. 890.5710 Section...Medicine Therapeutic Devices § 890.5710 Hot or cold disposable pack. (a) Identification. A hot or cold disposable pack is a device...

  3. 21 CFR 890.5710 - Hot or cold disposable pack.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 2014-04-01 2014-04-01 false Hot or cold disposable pack. 890.5710 Section...Medicine Therapeutic Devices § 890.5710 Hot or cold disposable pack. (a) Identification. A hot or cold disposable pack is a device...

  4. Hydraulic wellbore erosion while drilling

    SciTech Connect

    Chemerinski, B. [British Borneo Exploration, Houston, TX (United States); Robinson, L. [OGCI, Houston, TX (United States)

    1996-12-01

    This article is the first to identify nozzle hydraulic effects in a field evaluation of hole erosion. Common practice normally identifies annular velocity as the culprit for excessive hole washout. But field tests in this article clearly identify excessive nozzle hydraulics as the cause for hole erosion. Both oil-based and water-based drilling fluids were used during the field test. The primary contribution of this study is a simple guideline to assist drillers in preventing excessive hole erosion. This article describes drilling conditions and caliper logs, and discusses sequences of events that could explain the observations. Some preliminary guidelines are presented so that drillers can prevent erosion of the wellbore from high shear rates at bit nozzles.

  5. Hydraulic fracturing process and compositions

    SciTech Connect

    Constien, V. G.; King, M. T.

    1985-09-17

    Improved fracturing processes are described which use novel aqueous hydraulic fracturing fluids. The fluids comprise: (a) an aqueous medium, and (b) a thickening amount of a thickener composition comprising (i) a water-soluble or water-dispersible interpolymer having pendant hydrophobic groups chemically bonded thereto, (ii) a nonionic surfactant having a hydrophobic group(s) that is capable of associating with the hydrophobic groups on said organic polymer, and (iii) a water-soluble electrolyte. Additionally, the fluids preferably contain a stabilizing amount of a thiosulfate salt. As an example, an interpolymer of acrylamide and dodecyl acrylate was used in combination with a nonionic surfactant (HLB of about 10 to about 14) to thicken a dilute aqueous solution of KCl and sodium thiosulfate; the aqueous solution had excellent properties for use as a high temperature hydraulic fracturing fluid.

  6. Hydraulic fracture during epithelial stretching.

    PubMed

    Casares, Laura; Vincent, Romaric; Zalvidea, Dobryna; Campillo, Noelia; Navajas, Daniel; Arroyo, Marino; Trepat, Xavier

    2015-03-01

    The origin of fracture in epithelial cell sheets subject to stretch is commonly attributed to excess tension in the cells' cytoskeleton, in the plasma membrane, or in cell-cell contacts. Here, we demonstrate that for a variety of synthetic and physiological hydrogel substrates the formation of epithelial cracks is caused by tissue stretching independently of epithelial tension. We show that the origin of the cracks is hydraulic; they result from a transient pressure build-up in the substrate during stretch and compression manoeuvres. After pressure equilibration, cracks heal readily through actomyosin-dependent mechanisms. The observed phenomenology is captured by the theory of poroelasticity, which predicts the size and healing dynamics of epithelial cracks as a function of the stiffness, geometry and composition of the hydrogel substrate. Our findings demonstrate that epithelial integrity is determined in a tension-independent manner by the coupling between tissue stretching and matrix hydraulics. PMID:25664452

  7. Hydraulic redistribution may stimulate decomposition

    Microsoft Academic Search

    Zachary T. Aanderud; James H. Richards

    2009-01-01

    Roots influence root litter decomposition through multiple belowground processes. Hydraulic lift or redistribution (HR) by\\u000a plants is one such process that creates diel drying–rewetting cycles in soil. However, it is unclear if this phenomenon influences\\u000a decomposition. Since decomposition in deserts is constrained by low soil moisture and is stimulated when dry soils are rewetted,\\u000a we hypothesized that diel drying–rewetting, via

  8. GCFR thermal-hydraulic experiments

    SciTech Connect

    Schlueter, G.; Baxi, C.B.; Dalle Donne, M.; Gat, U.; Fenech, H.; Hanson, D.; Hudina, M.

    1980-01-01

    The thermal-hydraulic experimental studies performed and planned for the Gas-Cooled Fast Reactor (GCFR) core assemblies are described. The experiments consist of basic studies performed to obtain correlations, and bundle experiments which provide input for code validation and design verification. These studies have been performed and are planned at European laboratories, US national laboratories, Universities in the US, and at General Atomic Company

  9. PILOT-SCALE HYDRAULIC TESTING OF RESORCINOL FORMALDEHYDE ION EXCHANGE RESIN

    SciTech Connect

    Adamson, D.

    2009-05-28

    Savannah River National Laboratory (SRNL) performed pilot-scale hydraulic/chemical testing of spherical resorcinol formaldehyde (RF) ion exchange (IX) resin for the River Protection Project-Hanford Tank Waste Treatment & Immobilization Plant (WTP) Project. The RF resin hydraulic cycle testing was conducted in two pilot-scale IX columns, 1/4 and 1/2 scale. A total of twenty-three hydraulic/chemical cycles were successfully completed on the spherical RF resin. Sixteen of these cycles were completed in the 24-inch IX Column (1/2 scale column). Hydraulic testing showed that the permeability of the RF resin remained essentially constant, with no observed trend in the reduction of the permeability as the number of cycles increased. The permeability during the pilot-scale testing was 3 times better than the design requirements of the WTP full-scale IX system. The RF resin bed showed no tendency to form fissures or pack more densely as the number of cycles increased. Particle size measurements of the RF resin showed no indication of particle size change (for a given chemical) with cycles and essentially no fines formation. The permeability of the resin bed was uniform with respect to changes in bed depth. Upflow Regeneration and Simulant Introduction in the IX columns revealed another RF resin benefit; negligible radial pressures to the column walls from the swelling of resin beads. The hydraulic and chemical performance of the spherical RF resin during cycle testing was found to be superior to all other tested IX resins. The pilot-scale testing indicates that the RF resin is durable and should hold up to many hydraulic cycles in actual radioactive Cesium (Cs) separation.

  10. Hydraulic jumps with upstream shear

    NASA Astrophysics Data System (ADS)

    Ogden, Kelly; Helfrich, Karl

    2013-11-01

    Hydraulic jumps in flows with background shear are investigated, motivated by applications such as the flow over sills in Knight Inlet and the Pre-Bosphorus Channel. The full solution space and allowable solutions to several two-layer theories for hydraulic jumps with upstream shear are identified. The two-layer theories considered, including a recent theory by Borden et al. (JFM, 2012), are distinguished by how dissipation is partitioned between the layers. It is found that upstream shear with a faster and thinner lower layer causes an increase in bore speed, for a given jump height. Further, these two-layer solutions only exist for a limited range of upstream shear. 2D numerical simulations are conducted, guided by the two-layer theory solution space, and the results are compared to the theories. The simulations show the qualitative types of hydraulic transitions that occur, including undular bores, fully turbulent jumps, and conjugate state-like solutions; the type depends on the jump height and upstream shear for fixed upstream layer depths. Numerical simulations are used to investigate the mixing. Finally, a few 3D numerical simulations were made and are found to be consistent with the 2D results.

  11. Description and analysis of cored hydraulic fractures -- Lost Hills field, Kern County, California

    SciTech Connect

    Fast, R.E.; Murer, A.S.; Timmer, R.S. (Mobil E and P U.S. Inc., Bakersfield, CA (United States))

    1994-05-01

    An inclined observation well was drilled in shallow (2,000 ft) Opal-A diatomite. Seven sand-propped hydraulic fractures were cored and recovered. The hydraulic fractures were found within 5[degree] of the azimuth measured with tilt meters and were tilted 15[degree] from vertical, oriented perpendicular to the formation bedding dip. Hydraulic fractures widths ranged from less than one sand grain (40/60 mesh) to 0.4 in. Scanning electron microscopy (SEM) examination of fracture faces showed no damage to the matrix from proppant embedment or compaction, and no evidence of guard residue was detected in the proppant pack or on the formation face. Fractures appear to be considerably longer than modeled. Three closely spaced fractures are interpreted to be branches of a single hydraulic fracture treatment. This paper presents a description of the fractures recovered during coring in Well OO2. Findings related to fracture dimensions and orientations, fracture sources, fracture permeability measurements, and fracture characteristics (proppant embedment, presence of gel residue) are presented. Implications related to field development are discussed.

  12. Importance of mechanical testing of hydraulic fluids

    SciTech Connect

    Reichel, J. [DMT-Gesellschaft fuer Forschung und Pruefung mbH, Essen (Germany)

    1997-12-31

    Anti-wear properties of hydraulic fluids are important because hydraulic pump and motor wear is costly. Hydraulic fluid performance specifications represent minimum requirements. International hydraulic fluid performance standards are being developed by ISO/TC28/SC4 committee as draft (ISO DIS 11158 ``Specifications for Mineral Oil Hydraulic Fluids``). Performance specifications for non-mineral oil hydraulic fluids are also being developed. Typically, both the user and fluid manufacturer have insufficient information relating to the anti-wear properties of a new fluid to be used in hydraulic equipment, such as axial piston pumps, vane pumps or radial piston motors. Therefore, pump lubrication and operation requirements, preferably pre-existing in pump manufacturer`s specifications, must be determined. The required fluid lubrication properties may be determined by either laboratory pump tests or by a field trial, often at the expense of the customer. More preferably, the lubrication properties of the hydraulic fluid should be determined under mechanical conditions equivalent to field practice. In this paper, the use of both the vane pump test and the FZG Gear Test to predetermine the recommended hydraulic fluid lubrication performance will be discussed. In this way, fluid performance may be determined at significantly lower cost than more expensive large scale hydraulic pump and motor tests which are slower and more energy consuming.

  13. Is incest common in gray wolf packs?

    USGS Publications Warehouse

    Smith, D.; Meier, T.; Geffen, E.; Mech, L.D.; Burch, J.W.; Adams, L.G.; Wayne, R.K.

    1997-01-01

    Wolf packs generally consist of a breeding pair and their maturing offspring that help provision and protect pack young. Because the reproductive tenure in wolves often is short, reproductively mature offspring might replace their parents, resulting in sibling or parent-offspring matings. To determine the extent of incestuous pairings, we measure relatedness based on variability in 20 microsatellite loci of mated pairs, parent-offspring pairs and siblings in two populations of gray wolves. Our 16 sampled mated pairs had values of relatedness not overlapping those of known parent-offspring or sibling dyads, which is consistent with their being unrelated or distantly related. These results suggest that full siblings or a parent and their offspring rarely mate and that incest avoidance is an important constraint on gray wolf behavioral ecology.

  14. Mineral scale in gravel packed wells

    SciTech Connect

    Schmidt, T.; Soereide, F. [Statoil, Stavanger (Norway)

    1994-12-31

    Mineral scales of barium, strontium and calcium sulphate are well known to the oil industry. The most common scale is calcium carbonate. However carbonate, unlike the three other scales mentioned, is acid soluble and it is perhaps the sulphate scales which gives the greatest problems. One additional feature of the sulphate scales is that they very often coprecipitate radium sulphate which is radioactive and difficult to dispose of and troublesome to work with from a health and safety aspect. This paper presents the production history of gravel packed wells which have experienced the deposition and removal of mainly strontium sulphate (SrSO{sub 4}) scale. A scale prediction program is used to analyze the scale tendencies under both equilibrium and kinetic controlled conditions. The flow and scale characteristics of gravel packed and naturally completed wells are compared.

  15. Body packing: from seizures to laparotomy.

    PubMed

    Janczak, Joanna M; Beutner, Ulrich; Hasler, Karin

    2015-01-01

    Body packing is a common method for illegal drug trafficking. Complications associated with body packing can be severe and even lead to rapid death. Thus, a timely diagnosis is warranted. As most body packers initially do not show any symptoms, making a correct diagnosis can be rather challenging. We describe a case of a 41-year-old male, who was admitted with an epileptic seizure and who turned out to be a cocaine intoxicated body packer. Due to neurological and cardiovascular deterioration an emergency surgery was performed. Four bags of cocaine could be removed. We discuss the current management regimen in symptomatic and asymptomatic body packers and highlight pearls and pitfalls with diagnosis and treatment. PMID:25883813

  16. Performance comparison of different fuel cell vehicle power trains

    Microsoft Academic Search

    Gao Dawei; Jin Zhenhua; Lu Qingchun

    2008-01-01

    The power train of fuel cell vehicle adopts the hybridization with a fuel cell system and an energy storage system, which can be battery pack or super capacitor pack, in order to improve the fuel economy of the vehicle through regenerative braking and possibly to increase the specific power and to decrease the cost of the power train. The hybrid

  17. Hydraulic Redistribution: A Modeling Perspective

    NASA Astrophysics Data System (ADS)

    Daly, E.; Verma, P.; Loheide, S. P., III

    2014-12-01

    Roots play a key role in the soil water balance. They extract and transport water for transpiration, which usually represents the most important soil water loss in vegetated areas, and can redistribute soil water, thereby increasing transpiration rates and enhancing root nutrient uptake. We present here a two-dimensional model capable of describing two key aspects of root water uptake: root water compensation and hydraulic redistribution. Root water compensation is the ability of root systems to respond to the reduction of water uptake from areas of the soil with low soil water potential by increasing the water uptake from the roots in soil parts with higher water potential. Hydraulic redistribution is a passive transfer of water through the root system from areas of the soil with greater water potential to areas with lower water potential. Both mechanisms are driven by gradients of water potential in the soil and the roots. The inclusion of root water compensation and hydraulic redistribution in models can be achieved by describing root water uptake as a function of the difference in water potential between soil and root xylem. We use a model comprising the Richards equation for the water flow in variably saturated soils and the Darcy's equation for the water flow in the xylem. The two equations are coupled via a sink term, which is assumed to be proportional to the difference between soil and xylem water potentials. The model is applied in two case studies to describe vertical and horizontal hydraulic redistribution and the interaction between vegetation with different root depths. In the case of horizontal redistribution, the model is used to reproduce the fluxes of water across the root system of a tree subjected to uneven irrigation. This example can be extended to situations when only part of the root system has access to water, such as vegetation near creeks, trees at the edge of forests, and street trees in urban areas. The second case is inspired by recent agro-ecosystems experiments that combined different vegetation species to increase crop yield. The presence of deep rooted plants (nursing species) near shallow rooted crops (nursed species) enhanced crop growth thanks to vertical and horizontal hydraulic redistribution. The model is able to reproduce the patterns of water redistribution observed in this scenario.

  18. Integer and Fractional Packings in Dense Graphs

    Microsoft Academic Search

    Penny E. Haxell; Vojtech Rödl

    2001-01-01

      Let be any fixed graph. For a graph G we define to be the maximum size of a set of pairwise edge-disjoint copies of in G. We say a function from the set of copies of in G to [0, 1] is a fractional \\u000a \\u000a \\u000a -packing of G if for every edge e of G. Then is defined to be the

  19. Strengthening of face packing surfaces with powders

    Microsoft Academic Search

    N. N. Dorozhkin; V. N. Gimelfarb; L. P. Kashitsyn

    1983-01-01

    The primary reason for failure of centrifugal pumps used in chemical fiber production plants is failure of the tightness of the rubbing surfaces of the face packing surfaces caused by mechanical-corrosion wear. To increase the life, coatings of Ni-Cr-B-Si selffluxing alloy powders are normally applied to their working surface. A process has been developed for induction coalescing under the action

  20. Influence of fiber packing structure on permeability

    NASA Technical Reports Server (NTRS)

    Cai, Zhong; Berdichevsky, Alexander L.

    1993-01-01

    The study on the permeability of an aligned fiber bundle is the key building block in modeling the permeability of advanced woven and braided preforms. Available results on the permeability of fiber bundles in the literature show that a substantial difference exists between numerical and analytical calculations on idealized fiber packing structures, such as square and hexagonal packing, and experimental measurements on practical fiber bundles. The present study focuses on the variation of the permeability of a fiber bundle under practical process conditions. Fiber bundles are considered as containing openings and fiber clusters within the bundle. Numerical simulations on the influence of various openings on the permeability were conducted. Idealized packing structures are used, but with introduced openings distributed in different patterns. Both longitudinal and transverse flow are considered. The results show that openings within the fiber bundle have substantial effect on the permeability. In the longitudinal flow case, the openings become the dominant flow path. In the transverse flow case, the fiber clusters reduce the gap sizes among fibers. Therefore the permeability is greatly influenced by these openings and clusters, respectively. In addition to the porosity or fiber volume fraction, which is commonly used in the permeability expression, another fiber bundle status parameter, the ultimate fiber volume fraction, is introduced to capture the disturbance within a fiber bundle.