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1

Hydraulically refueled battery employing a packed bed metal particle electrode  

DOEpatents

A secondary zinc air cell, or another selected metal air cell, employing a spouted/packed metal particle bed and an air electrode is described. More specifically, two embodiments of a cell, one that is capable of being hydraulically recharged, and a second that is capable of being either hydraulically or electrically recharged. Additionally, each cell includes a sloped bottom portion to cause stirring of the electrolyte/metal particulate slurry when the cell is being hydraulically emptied and refilled during hydraulically recharging of the cell. 15 figs.

Siu, S.C.; Evans, J.W.

1998-12-15

2

Hydraulically refueled battery employing a packed bed metal particle electrode  

DOEpatents

A secondary zinc air cell, or another selected metal air cell, employing a spouted/packed metal particle bed and an air electrode. More specifically, two embodiments of a cell, one that is capable of being hydraulically recharged, and a second that is capable of being either hydraulically or electrically recharged. Additionally, each cell includes a sloped bottom portion to cause stirring of the electrolyte/metal particulate slurry when the cell is being hydraulically emptied and refilled during hydraulically recharging of the cell.

Siu, Stanley C. (Castro Valley, CA); Evans, James W. (Piedmont, CA)

1998-01-01

3

Fluid Power/Basic Hydraulics. Instructor's Guide.  

ERIC Educational Resources Information Center

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…

Stanbery, Richard

4

MARKET POWER IN BEEF PACKING: FEEDLOT \\  

Microsoft Academic Search

Concentration in the beef packing industry has been rising for the past 25 years. Many studies of market power in beef packing are based on the conjectural variations framework, which depends on accurate estimates of packer input and processing costs. We propose an alternative measure of packer behavior which does not rely on estimates of packer costs. We also suggest

Lynn Hunnicutt; Michelle Crook; DeeVon Bailey

2001-01-01

5

Space Shuttle Upgrades Advanced Hydraulic Power System  

NASA Technical Reports Server (NTRS)

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.

2004-01-01

6

Microbial community in methanogenic packed-bed reactor successfully operating at short hydraulic retention time.  

PubMed

The microbial community in a thermophilic anaerobic packed-bed reactor, which had been successfully operated to convert acetic and butyric acids to methane at a short hydraulic retention time (from 24 h to 1.9 h), was investigated. Archaea closely related to known methanogens were detected by 16S rRNA gene analyses of the effluents, together with diverse types of unidentified bacteria. PMID:16716930

Sasaki, Kengo; Haruta, Shin; Tatara, Masahiro; Yamazawa, Akira; Ueno, Yoshiyuki; Ishii, Masaharu; Igarashi, Yasuo

2006-03-01

7

Ocean thermal gradient hydraulic power plant.  

PubMed

Solar energy stored in the oceans may be used to generate power by exploiting ploiting thermal gradients. A proposed open-cycle system uses low-pressure steam to elevate vate water, which is then run through a hydraulic turbine to generate power. The device is analogous to an air lift pump. PMID:17813707

Beck, E J

1975-07-25

8

Lightweight, Flexible, Thin, Integrated Solar-Power Packs  

NASA Technical Reports Server (NTRS)

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.

Hanson, Robert R.

2004-01-01

9

Control issues for a hydraulically powered dissimilar teleoperated system  

SciTech Connect

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.)

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

1995-12-31

10

Hydraulic characteristics in superconducting power transmission cables  

NASA Astrophysics Data System (ADS)

The hydraulic characteristics of sub-cooled nitrogen in superconducting power transmission line have been investigated to design the transmission line. To estimate the friction factor in corrugated pipes, the pressure drop was measured across a 10-m length corrugated pipe for various mass flow rates and compared with that in smooth pipes (Proc. 17th Cryo. Eng. Conf. (1998) 475). Another concern is the cooling method of the transmission line. A usual counter-flow cooling method has been found to be very difficult at liquid nitrogen temperature, because the thermal conductivity of the dielectric materials between the counter-flows at liquid nitrogen temperature are 10 times larger than that at liquid helium temperature. Instead, an externally cooling method was proposed (Proc. 17th Cryo. Eng. Conf. (1998) 475). As the results, the friction factor of outer corrugated jacket within three cables has become an important parameter to design the transmission lines. This friction factor is measured and compared with various formulas in this paper.

Fuchino, S.; Tamada, N.; Ishii, I.; Higuchi, N.

2001-05-01

11

HIGH-POWER RF DISTRIBUTION SYSTEMFOR THE 8-PACK PROJECT  

SciTech Connect

The 8-Pack Project at SLAC is a prototype rf system whose goal is to demonstrate the high-power X-band technology developed in the NLC/GLC (Next/Global Linear Collider) program. In its first phase, it has reliably produced a 400 ns rf pulse of over 500 MW using a solidstate modulator, four 11.424 GHz klystrons and a dualmoded SLED-II pulse compressor. In Phase 2, the output power of the system has been delivered into the bunker of the NLCTA (Next Linear Collider Test Accelerator) and divided between several accelerator structures for beam acceleration. The authors describe here the design, cold-test measurements, and processing of this power distribution system. Due to the high power levels and the need for efficiency, overmoded waveguide and components are used. For power transport, the TE{sub 01} mode is used in 7.44 cm and 4.064 cm diameter circular waveguide. Only near the structures is standard WR90 rectangular waveguide employed. Components used to manipulate the rf power include transitional tapers, mode converters, overmoded bends, fractional directional couplers, and hybrids.

Nantista, C

2004-08-24

12

The research of wind power optimized capacity configuration in hydraulic power system  

Microsoft Academic Search

Buerjin power grid of Xinjiang province in China is an alone hydraulic-wind power mutual compensation system, which is composed of two hydraulic generators with capacity of 2000 KW and one with 2500 KW and seven wind generators with capacity of 150 KW, the wind power capacity account for almost 13.0 percent of total power system capacity. In order to study

Feng-ting Li; Qin Chao; Xun-jiang Dai

2008-01-01

13

The Free Piston Power Pack: Sustainable Power for Hybrid Electric Vehicles  

Microsoft Academic Search

The Free Piston Power Pack (FP3) represents a new concept in the design of free piston engines. The FP3 is a free piston engine with an integral generator for electrical power output. Its novel features are an integral compressor and a passive intake valve located in the head of the piston. These improvements eliminate undesirable problems that affect conventional free

Douglas Carter; Edward Wechner

14

Distillation columns containing structured packings: A comprehensive model for their performance. 1. Hydraulic models  

Microsoft Academic Search

A mechanistically-based model has been developed to aid the analysis and design of distillation columns containing structured packings of the corrugated plate type. The model encompasses the important, and related, parameters of liquid holdup, pressure drop, flooding, and mass-transfer efficiency. Since it deals with the countercurrent contacting of liquid with gas or vapor, the model may also be applied to

J. Antonio Rocha; Jose L. Bravo; James R. Fair

1993-01-01

15

HEAT TRANSFER AND HYDRAULIC RESISTANCE IN CLOSE-PACKED ROD BUNDLES PROVIDED WITH VOIDS  

Microsoft Academic Search

Grouping the fuel rods in the reactor in the form of closely-packed ; bundles represent a simplified design which does not require special devices to ; prevent deformation of the rods. The relatively high void content of 21.5% of ; this arrangement ensures a high flow rate of the coolant through the reactor. In ; order to obtain additional information

P. A. Ushakov; V. I. Subbotin; B. N. Gabrianovich; V. D. Talanov; I. P. Sviridenko

1962-01-01

16

State Control in Hydroelectric Power Plants. Hydraulic Loss Monitoring.  

National Technical Information Service (NTIS)

The report describes a method of monitoring the hydraulic losses in a hydroelectric power plant. By means of measurements in the water way, of the electric power, inflow and water level, the flow of water and loss coefficients of the water way and the tur...

T. K. Nielsen J. A. Sandvik O. Skarstein

1987-01-01

17

Power packs: A passive approach to extinguishing fire in combat vehicles  

Microsoft Academic Search

Thin (12.7 and 6.4 mm) panels of fire extinguishing powder in a honeycomb matrix were tested for their ability to extinguish fires in the FAASV ammunition resupply vehicle. These powder packs were applied to the exterior of hydraulic fluid reservoirs and fuel cells for protection from hydrocarbon fires caused by shaped charge jets penetrating the fluid containers. It was found

Anthony E. Finnerty

1991-01-01

18

Hydraulic Bureaucracies and the Hydraulic Mission: Flows of Water, Flows of Power  

Microsoft Academic Search

Anchored in 19th century scientism and an ideology of the domination of nature, inspired by colonial hydraulic feats, and fuelled by technological improvements in high dam constructions and power generation and transmission, large-scale water resources development has been a defining feature of the 20th century. Whether out of a need to increase food production, raise rural incomes, or strengthen state

F. Molle; P. P. Mollinga; P. Wester

2009-01-01

19

Hydraulics.  

ERIC Educational Resources Information Center

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)…

Decker, Robert L.; Kirby, Klane

20

Design of a MR hydraulic power actuation system  

NASA Astrophysics Data System (ADS)

A magnetorheological (MR) fluid-based hydraulic power system is analyzed and experimentally validated by testing a prototype. A set of MR valves is proposed to implement within a Wheatstone bridge hydraulic power circuit to drive a hydraulic actuator using a pump. The MR valves are used in place of conventional mechanical servo valves. The proposed use of MR valves in hydraulic actuator systems has many advantages. First, MR valves have no moving parts, enhancing reliability. Second, the MR valves operate at the same speed as the actuation bandwidth (typically below twenty Hz in our applications). Third, the actuator relies on flow rates for a given pump speed, and avoids, to a large degree fluid compliance. Fourth, if a change in stroke direction is required, the flow through each of the MR valves can be controlled smoothly via changing the applied magnetic field. The performance of the Wheatstone bridge with MR valves is theoretically derived using three different models of the MR fluid behaviors: an idealized model, a Bingham-plastic model and a biviscous model. The analytical system efficiency in each case is compared, and departures from ideal behavior are recognized. The driving force and efficiency will be evaluated in the MR hydraulic power actuator system for both Bingham plastic and biviscous flows. An MR valve is designed using a magnetic finite element analysis. The magnetic flux density developed in the MR valve are verified by analytical and experimental methods. The yield stresses achieved in the MR valve due to the applied current are also measured to validate the design methodology. The overall performance of the MR fluid based hydraulic power system is described using the experimental MR valve performance data.

Yoo, Jin-Hyeong; Sirohi, Jayant; Wereley, Norman M.

2001-08-01

21

Hydraulics.  

ERIC Educational Resources Information Center

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…

Engelbrecht, Nancy; And Others

22

Modeling and Co-simulation of Hydraulic Power Steering System  

Microsoft Academic Search

Hydraulic power steering systems, which can provide large steering assist force, are widely used for heavy- duty commercial vehicles to enhance the driving comfort. Such systems have great influences on vehicle controllability, steering stability and safety. However, interpolated table from experiment data was used as the assist force to study the vehicle dynamics in many previous works, so the transient

Ying Sun; Ping He; Yunqing Zhang; Liping Chen

2011-01-01

23

Hydraulics.  

ERIC Educational Resources Information Center

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,…

Decker, Robert L.

24

An Improved Lead–Acid Battery Pack Model for Use in Power Simulations of Electric Vehicles  

Microsoft Academic Search

A new model for a lead–acid battery pack is proposed for use in power simulations of electric vehicles. A linear approximation using a constant voltage drop has been used to model the charge-transfer resistance of the battery pack, and an exponential voltage-recovery equation has been used to model the transient capacitance effects following a period of discharge. The new model

Rebecca Carter; Andrew Cruden; Peter J. Hall; Ammar S. Zaher

2012-01-01

25

Accelerated electromechanical dynamic modelling of a distributed generation power pack  

Microsoft Academic Search

Distributed diesel generation is widely used to supply electric power in a variety of applications. These applications range from backup power supply systems and combined wind- diesel generation to providing power in places where grid connection is either technically impractical or financially uneconomic. Modelling and optimisation of such systems as a whole is extremely difficult due to the long-time load

C. I. Hill; P. Zanchetta; S. V. Bozhko

2011-01-01

26

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.

2011-01-03

27

A Methodology for Selecting High Thermal-Hydraulic Performance Fuel Configurations for Tightly Packed Epithermal Core Designs  

Microsoft Academic Search

Cylindrical fuel pins with wires are the design of choice for tightly packed fuel arrays. However, it is important to investigate novel fuel configurations in order to increase the thermal margins. Hence, new fuel designs have been studied for the epithermal option of the light water-cooled IRIS core. These designs are also of potential use in other tightly packed, epithermal

Antonino Romano; Neil E. Todreas

2002-01-01

28

Hydraulically powered soil core sampler and its application to soil density and porosity estimation  

Microsoft Academic Search

The design of a hydraulically powered soil core sampler used to collect undisturbed soil samples at different depths in the field is presented. The hydraulic actuation of the coring probe reduces the physical effort and time required by the operators. The device is constructed from a three-point hitch frame equipped with a gearbox, retractable legs, hydraulic cylinder and probe. The

Nidal H Abu-Hamdeh; Hamid F Al-Jalil

1999-01-01

29

Power-law friction in closely packed granular materials  

NASA Astrophysics Data System (ADS)

In order to understand the nature of friction in dense granular materials, a discrete element simulation on granular layers subjected to isobaric plain shear is performed. It is found that the friction coefficient increases as the power of the shear rate, the exponent of which does not depend on the material constants. Using a nondimensional parameter that is known as the inertial number, the power law can be cast in a generalized form so that the friction coefficients at different confining pressures collapse on the same curve. We show that the volume fraction also obeys a power law.

Hatano, Takahiro

2007-06-01

30

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

SciTech Connect

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.)

Not Available

1993-12-01

31

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

SciTech Connect

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 75 citations and includes a subject term index and title list.)

NONE

1995-02-01

32

49 CFR 173.172 - Aircraft hydraulic power unit fuel tank.  

Code of Federal Regulations, 2010 CFR

...and Class 7 § 173.172 Aircraft hydraulic power unit fuel tank. Aircraft hydraulic power unit fuel...installation as complete units in aircraft are excepted from the specification...The unit must consist of an aluminum pressure vessel made...

2010-10-01

33

49 CFR 173.172 - Aircraft hydraulic power unit fuel tank.  

Code of Federal Regulations, 2010 CFR

...and Class 7 § 173.172 Aircraft hydraulic power unit fuel tank. Aircraft hydraulic power unit fuel...installation as complete units in aircraft are excepted from the specification...The unit must consist of an aluminum pressure vessel made...

2009-10-01

34

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

Code of Federal Regulations, 2010 CFR

... 2009-10-01 2009-10-01 false Electric and hydraulic power supply. 111.97-5...SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Electric Power-Operated Watertight Door Systems...

2009-10-01

35

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

Code of Federal Regulations, 2013 CFR

... 2013-10-01 2013-10-01 false Electric and hydraulic power supply. 111.97-5...SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Electric Power-Operated Watertight Door Systems...

2013-10-01

36

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...SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Electric Power-Operated Watertight Door Systems...

2010-10-01

37

Power and thermal characterization of a lithium-ion battery pack for hybrid-electric vehicles  

Microsoft Academic Search

A 1D electrochemical, lumped thermal model is used to explore pulse power limitations and thermal behavior of a 6Ah, 72 cell, 276V nominal Li-ion hybrid-electric vehicle (HEV) battery pack. Depleted\\/saturated active material Li surface concentrations in the negative\\/positive electrodes consistently cause end of high-rate (?25C) pulse discharge at the 2.7Vcell?1 minimum limit, indicating solid-state diffusion is the limiting mechanism. The

Kandler Smith; Chao-Yang Wang

2006-01-01

38

Design and analysis of a thermal hydraulic integral test facility for Bushehr nuclear power plant  

Microsoft Academic Search

In this paper, design and analysis of a thermal hydraulic integral test facility for Bushehr Nuclear Power Plant (NPP) is presented. The Bushehr Integral Test Facility (BITF) is a test facility designed to model the thermal-hydraulic behaviours of the Bushehr NPP (VVER-1000) pressurized water reactors currently in use in IRAN. These reactors have unique features that differ from other PWR

Toraj Khoshnevis; Jalil Jafari; Mostafa Sohrabpour

2009-01-01

39

Performance of Army Arctic Engine Oils in Hydraulic and Power Transmission Fluid Systems.  

National Technical Information Service (NTIS)

Development of the Army's new Arctic Engine Oil (OEA) Specification MIL-L-46167 required numerous laboratory and field engine evaluations as well as large scale laboratory and field testing of these new lubricants in military hydraulic and power transmiss...

S. J. Lestz P. D. Hopler T. C. Bowen

1975-01-01

40

Uprated dc power system and thermal-hydraulic facilities at Columbia University. Final report  

Microsoft Academic Search

The necessity of carrying out large scale nuclear thermal-hydraulic simulations is increasing. Such experiments call for large power sources, and to meet those requirements the D.C. power system at the Heat Transfer Research Facility of Columbia University has been upgraded to 11.5 MW. The uprated system, its installations, various subsystems, and operations are described. The thermal-hydraulic loops and their auxiliary

W. E. Hovemeyer; S. R. Sreepada; J. E. Casterline

1978-01-01

41

Aluminide coatings on iron-chromium-molybdenum steel synthesized by pack cementation for power generation applications  

NASA Astrophysics Data System (ADS)

Aluminide coatings on ferritic/martensite Fe-9Cr-1Mo steel substrates for power generation applications were developed via a pack cementation process at both high temperatures (1050°C) and low temperatures (650 and 700°C). Thermodynamic analysis was first conducted using HSC 5.0 software to provide a guideline for the selection of a masteralloy and the amount of the activator in the pack. Equilibrium partial pressures of halide gaseous species were calculated for packs containing Cr-Al binary alloys with Al contents varying from 5wt%Al to pure Al at both 1050°C and 700°C (Except for 650°C, at which only pure Al masteralloy was used). The calculation was also made for packs containing Hf, HfO2 or HfCl4 for developing Hf-modified aluminide coatings. At 1050°C, both simple and Hf-modified aluminide coatings were synthesized using a Cr-25wt.%Al binary masteralloy with a noncontact pack arrangement. Oxidation testing in air + 10vol.% H2O at 700°C indicates that simple pack aluminide coatings exhibited similar oxidation behavior to the model coatings fabricated via chemical vapor deposition (CVD). For up to 4,600h, Hf-modified aluminide coatings showed an improved oxidation resistance to CVD coatings. Low temperature aluminide coatings were synthesized at temperatures of 650 and 700°C, below the tempering temperature of the ferritic/martensite steel substrate. Initial coating development showed that a continuous Fe 2Al5 coating layer was deposited at 650°C with pure Al masteralloy. However, the coating thickness was not uniform and cracks were observed in the coatings. Cr-25wt%Al and Cr-15wt.%Al binary alloys with reduced Al activities were used to reduce the tendency of forming the brittle, Al-rich Fe2Al5 phase. With Cr-25wt.%Al masteralloy at 700°C, the synthesized coating consisted of a thin layer of Fe2Al 5 and an underlying layer of FeAl. The masteralloy of Cr-15wt.%Al was then utilized to further reduce the Al activity, and FeAl coatings with improved uniformity of coating thickness were obtained. The effect of the amount of Cr-15wt.%Al masteralloy on the FeAl coating thickness and composition profiles was also investigated.

Wang, Yongqing

42

Constant-Pressure Hydraulic Pump: Higher efficiency and constant output pressure are made possible by a unique gas-to-hydraulic power converter.  

National Technical Information Service (NTIS)

This citation summarizes a one page announcement of technology available for utilization. Constant output pressure in a gasdriven hydraulic pump would be assured in a new design for a gas-to-hydraulic power converter. With a force-multiplying ring attache...

1982-01-01

43

Analysis on the capacity degradation mechanism of a series lithium-ion power battery pack based on inconsistency of capacity  

NASA Astrophysics Data System (ADS)

The lithium-ion battery has been widely used as an energy source. Charge rate, discharge rate, and operating temperature are very important factors for the capacity degradations of power batteries and battery packs. Firstly, in this paper we make use of an accelerated life test and a statistical analysis method to establish the capacity accelerated degradation model under three constant stress parameters according to the degradation data, which are charge rate, discharge rate, and operating temperature, and then we propose a capacity degradation model according to the current residual capacity of a Li-ion cell under dynamic stress parameters. Secondly, we analyze the charge and discharge process of a series power battery pack and interpret the correlation between the capacity degradations of the battery pack and its charge/discharge rate. According to this cycling condition, we establish a capacity degradation model of a series power battery pack under inconsistent capacity of cells, and analyze the degradation mechanism with capacity variance and operating temperature difference. The comparative analysis of test results shows that the inconsistent operating temperatures of cells in the series power battery pack are the main cause of its degradation; when the difference between inconsistent temperatures is narrowed by 5 °C, the cycle life can be improved by more than 50%. Therefore, it effectively improves the cycle life of the series battery pack to reasonably assemble the batteries according to their capacities and to narrow the differences in operating temperature among cells.

Wang, Zhen-Po; Liu, Peng; Wang, Li-Fang

2013-08-01

44

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

NASA Technical Reports Server (NTRS)

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.

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

2003-01-01

45

Modern water hydraulics—the new energy-transmission technology in fluid power  

Microsoft Academic Search

With the increasing demand for an environmentally-friendly fluid medium in the fluid-power industries, recent advances in water hydraulics technology have sparked renewed interest in the application of water, instead of oil, as the energy-transmission medium. This paper introduces the history of water hydraulics and its present research. The advantages and disadvantages of water as an energy-transmission medium are discussed. A

G. H. Lim; P. S. K. Chua; Y. B. He

2003-01-01

46

Power generation costs and ultimate thermal hydraulic power limits in hypothetical advanced designs with natural circulation  

SciTech Connect

Maximum power limits for hypothetical designs of natural circulation plants can be described analytically. The thermal hydraulic design parameters are those which limit the flow, being the elevations, flow areas, and loss coefficients. WE have found some simple ``design`` equations for natural circulation flow to power ratio, and for the stability limit. The analysis of historical and available data for maximum capacity factor estimation shows 80% to be reasonable and achievable. The least cost is obtained by optimizing both hypothetical plant performance for a given output,a nd the plant layout and design. There is also scope to increase output and reduce cost by considering design variations of primary and secondary pressure, and by optimizing component elevations and loss coefficients. The design limits for each are set by stability and maximum flow considerations, which deserve close and careful evaluation.

Duffey, R.B.; Rohatgi, U.S.

1996-12-31

47

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

Code of Federal Regulations, 2013 CFR

...power and control-materials and pressure design. 128.240 Section 128.240 Shipping...EQUIPMENT AND SYSTEMS Materials and Pressure Design § 128.240 Hydraulic or pneumatic power and controlâmaterials and pressure design. (a) Each standard piping...

2013-10-01

48

Proceedings of international nuclear power plant thermal hydraulics and operations topical meeting  

SciTech Connect

This conference presents information on the following topics: analysis of BWR transients; thermal hydraulic experiments and their interpretation; analysis for reactor setpoints and technical specifications; thermal hydraulic analysis related to thermal margin; regulatory requirements for safety analysis and operation; implementation of post-TMI backfit requirements; power plant testing, operation, and maintenance experience; nuclear manpower planning and personnel training; application of probabilistic risk assessment technique on reactor operation and design; equipment qualification; thermal performance improvements of nuclear power plants; and analysis of PWR transients. Ninety-four papers were presented.

Chao, J.; Chiu, C.

1984-01-01

49

PowerPACK: A wireless power distribution system for wearable devices  

Microsoft Academic Search

Motivated by the prevalence of small, battery-powered devices in many pervasive computing research and deployment scenarios, and the frustration encountered when a particular device is found to be useless due to a discharged internal battery, we present a backpack-worn wireless (non-contact) power distribution system. This system is designed to distribute power from a single point of generation or bulk storage

Travis Deyle; Matthew Reynolds

2008-01-01

50

THE THERMAL AND HYDRAULIC CHARACTERISTICS OF POWER REACTOR FUEL BUNDLE DESIGNS  

Microsoft Academic Search

The type of fuel bundle evolved for the various Canadian heavy water-; moderated power reactors is described. The data necessary for estimating the ; thermal and hydraulic characteristics of this type of fuel bundle are indicated. ; The calculations and experimentation undertaken in the general fields of fluid ; flow, heat transfer, and coolant mixing are then described. The future

G. T. Leaist; R. D. Page; R. J. Klock

1963-01-01

51

Survey of thermal-hydraulic models of commercial nuclear power plants  

SciTech Connect

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.

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

1992-12-01

52

Survey of thermal-hydraulic models of commercial nuclear power plants  

SciTech Connect

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.

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

1992-12-01

53

Geodynamic Effects on the Dams in Cascade of the Sulak Hydraulic Power Systems  

Microsoft Academic Search

In view of the passage of the Federal statute, ”On the safety of hydraulic structures,” in 1999 and 2000 the Institute of Physics of the Earth of the Russian Academy of Sciences, the Dagestan Power Authority, and the Dagestan Scientific Center (Russian Academy of Sciences) carried out field investigations of geodynamic effects on the safety of the cascade of Sulak

A. N. Marchuk; A. R. Abakarov; M. G. Daniyalov; O. A. Asmanov; M. M. Mirzaliev; R. A. Levkovich

2001-01-01

54

The Wolf Pack: Power Shared and Power Earned--Building a Middle School Nation.  

ERIC Educational Resources Information Center

Discusses a middle school project to create a "nation" within the classroom environment in order to explore questions of identity, problem solving, inequity and power, as well as issues of United States history. Includes governance documents and sample class activities. (JPB)

Frost, Richard; Olson, Erik; Valiquette, Lynne

2000-01-01

55

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

Microsoft Academic Search

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

Thomas Conboy; Pavel Hejzlar

2006-01-01

56

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

Microsoft Academic Search

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

Ross Henderson

2006-01-01

57

LVP modeling and dynamic characteristics prediction of a hydraulic power unit in deep-sea  

NASA Astrophysics Data System (ADS)

A hydraulic power unit (HPU) is the driving "heart" of deep-sea working equipment. It is critical to predict its dynamic performances in deep-water before being immerged in the seawater, while the experimental tests by simulating deep-sea environment have many disadvantages, such as expensive cost, long test cycles, and difficult to achieve low-temperature simulation, which is only used as a supplementary means for confirmatory experiment. This paper proposes a novel theoretical approach based on the linear varying parameters (LVP) modeling to foresee the dynamic performances of the driving unit. Firstly, based on the varying environment features, dynamic expressions of the compressibility and viscosity of hydraulic oil are derived to reveal the fluid performances changing. Secondly, models of hydraulic system and electrical system are accomplished respectively through studying the control process and energy transfer, and then LVP models of the pressure and flow rate control is obtained through the electro-hydraulic models integration. Thirdly, dynamic characteristics of HPU are obtained by the model simulating within bounded closed sets of varying parameters. Finally, the developed HPU is tested in a deep-sea imitating hull, and the experimental results are well consistent with the theoretical analysis outcomes, which clearly declare that the LVP modeling is a rational way to foresee dynamic performances of HPU. The research approach and model analysis results can be applied to the predictions of working properties and product designs for other deep-sea hydraulic pump.

Cao, Xue-peng; Ye, Min; Deng, Bin; Zhang, Cui-hong; Yu, Zu-ying

2013-03-01

58

Recognizing hydraulic power plant and aimpoint choosing from clutter background  

NASA Astrophysics Data System (ADS)

Large power stations are usually chosen as the target for missiles guided by IR seeker. This paper presents an aimpoint finding algorithm. The high light blob of boiler and straight lines of chimneys or water cooling towers are taken as the reference feature objects for locating and keeping the aimpoint form long to short distance. Some experiment results are given to show the validity of our method.

Li, Zhiyong; Yang, Weiping; Shen, Hai-Xin

1997-10-01

59

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

NASA Technical Reports Server (NTRS)

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.

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

2012-01-01

60

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

DOEpatents

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.

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

2001-06-22

61

Asymmetric Base-Bleed Effect on Aerospike Plume-Induced Base-Heating Environment During Power-Pack Out  

NASA Technical Reports Server (NTRS)

A computational heat transfer design methodology was developed to study tbe dual-engine linear aerospike plume-induced base-heating environment during one power-pack out, in ascent flight. It includes a three-dimensional, finite volume, viscous, chemically reacting, and pressure-based computational fluid dynamics formulation, a special base-bleed boundary condition, and 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 during static linear aerospike engine tests. The base-heating environment of 18 trajectory points secected from three power-pack out scenarios was computed. The computed asymmetric base-heating physics were analyzed. The power-pack out condition has the most impact on convective base heating when it happens early in flight. The soume of its impact comes from the asymmetric and reduced base bleed.

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

2003-01-01

62

Hydraulic Car  

NSDL National Science Digital Library

In this activity, learners build cars using syringes and water-powered hydraulics. Learners construct the car frame out of cardboard and set up a hydraulic system to raise and lower the car. Use this project to introduce learners to incompressible fluids and Pascal's Principle.

Workshop, Watsonville E.

2011-01-01

63

Valve Packing  

NASA Technical Reports Server (NTRS)

"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.

1992-01-01

64

Study on the Uneven cells Problem of the Power Battery Pack in the Automotive Application by ECM  

NASA Astrophysics Data System (ADS)

Uneven cells problem is a universal phenomenon in the cell grouping application. It will cause performance and safety problems if the uneven is not considered during pack design and application, especially for the automotive application. The ECM model is used for the study of the uneven cells phenomenon of the power battery pack in the automotive application. An EV model and a FCV model are used for simulating the current profiles for two representative powertrain systems. The links of the ECM are set in five conditions for separate study on the impact. The results show different impact on the SOC and voltage with the same sets of links for the two powertrain model. The cell grouping design and the balance algorithm should be adjusted according to the different application background when the uneven cells problems are considered.

Jiayuan, Wang; Zechang, Sun; Xuezhe, Wei; Haifeng, Dai

65

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

NASA Astrophysics Data System (ADS)

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.

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

2010-06-01

66

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

SciTech Connect

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)

Schriener, T. M. [Inst. for Space and Nuclear Power Studies, Univ. of New Mexico, Albuquerque, NM (United States) [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) [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

67

Thermal-hydraulics for space power, propulsion, and thermal management system design  

SciTech Connect

The present volume discusses thermal-hydraulic aspects of current space projects, Space Station thermal management systems, the thermal design of the Space Station Free-Flying Platforms, the SP-100 Space Reactor Power System, advanced multi-MW space nuclear power concepts, chemical and electric propulsion systems, and such aspects of the Space Station two-phase thermal management system as its mechanical pumped loop and its capillary pumped loop's supporting technology. Also discussed are the startup thaw concept for the SP-100 Space Reactor Power System, calculational methods and experimental data for microgravity conditions, an isothermal gas-liquid flow at reduced gravity, low-gravity flow boiling, computations of Space Shuttle high pressure cryogenic turbopump ball bearing two-phase coolant flow, and reduced-gravity condensation.

Krotiuk, W.J.

1990-01-01

68

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

NASA Astrophysics Data System (ADS)

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.

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

2014-04-01

69

Thermal-hydraulic tests of a recirculation cooling installation for the Rostov nuclear power station  

NASA Astrophysics Data System (ADS)

Results obtained from thermal-hydraulic tests of the recirculation cooling installation used as part of the air cooling system under the containments of the Rostov nuclear power station Units 3 and 4 are presented. The operating modes of the installation during normal operation (air cooling on the surface of finned tubes), under the conditions of anticipated operational occurrences (air cooling and steam condensation from a steam-air mixture), and during an accident (condensation of pure steam) are considered. Agreement is obtained between the results of tests and calculations carried out according to the recommendations given in the relevant regulatory documents. A procedure of carrying out thermal calculation for the case of steam condensation from a steam-air mixture on the surface of fins is proposed. The possibility of efficient use of the recirculation cooling installation in the system for reducing emergency pressure under the containment of a nuclear power station is demonstrated.

Balunov, B. F.; Balashov, V. A.; Il'in, V. A.; Krayushnikov, V. V.; Lychakov, V. D.; Meshalkin, V. V.; Ustinov, A. N.; Shcheglov, A. A.

2013-09-01

70

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

SciTech Connect

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)

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

2006-07-01

71

Optimisation of a distributed generation power pack using a novel dynamic system model including efficiency characteristics  

Microsoft Academic Search

Distributed diesel generation is still widely used to supply electric power in a variety of applications. These applications range from backup power supply systems and combined wind-diesel generation to providing power in places where grid connection is either technically impractical or financially uneconomic. Due to the ever increasing cost of diesel fuel and the environmental issues associated with its use,

C. I. Hill; P. Zanchetta; S. V. Bozhko; J. Li

2011-01-01

72

A study of thermal-hydraulic requirements for increasing the power rates for natural-circulation boiling water reactors  

Microsoft Academic Search

In this paper, the feasibility of higher power rates for natural-circulation boiling water reactors (BWRs) is studied with the objective of examining the flexibility of the plant power rate in constructing such plants to cope with the increasing demand for electricity. By applying existing one-dimensional design codes, the riser heights necessary to meet two major thermal-hydraulic requirements, i.e., critical power

A. Yasuo; F. Inada; M. Hidaka

1992-01-01

73

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...

2009-07-22

74

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

SciTech Connect

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.

Block, Gus

2011-07-31

75

Conversion rates in power plant plumes based on filter pack data: The oil fired Northport plume  

NASA Astrophysics Data System (ADS)

More than 60 airborne plume studies were conducted at a large oil fired power station during a 3 build1/2 year period. These studies were conducted to determine the typical rate of formation of sulfate in the plume and the conditions which most influence these atmospheric processes. The power plant chosen for this program is located in the northeast region of the U.S. and during the course of these studies a typical variety of meteorological conditions were encountered. This is probably the most extensive body of plume data ever gathered from a single power plant. The effect on the oxidation rate was explored for a wide variety of and variation in meteorological conditions. Plume sulfate rarely accounted for more than 5 % of the total plume sulfur even for plume travel times of up to 4 h. For most experiments more than half of the observed plume sulfate was that emitted from the power plant units. The rate of atmospheric oxidation of sulfur dioxide to sulfate was not readily discernible due to the low rate of conversion and the relatively high amount of the sulfate emitted. The results reported in this paper generally indicate an apparent oxidation rate of less than 1 % h -. A diurnal influence or effects due to changes in various meteorological conditions are difficult to discern.

Garber, Robert W.; Forrest, Joseph; Newman, Leonard

76

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

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

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

2008-10-01

77

In vivo measurements of skeletal muscle in a linear configuration powering a hydraulically actuated VAD.  

PubMed

Linear contracting skeletal muscle can provide more power and physiologic efficiency for cardiac assistance than muscle wrapping configurations. In this study, the insertion of the porcine latissimus dorsi muscle was removed from the humerus and reattached to a muscle powered ventricular assist device (MVAD), consisting of a mechanical to hydraulic piston energy convertor coupled to a Thoratec VAD. Effects of muscle preload stretch and thoracodorsal nerve stimulation parameters on in vivo unconditioned muscle work and MVAD stroke volume were studied. Stroke work increased linearly with muscle preload, and the slope of this relationship (Mprsw) provided an index of muscle "contractility," similar to the preload-recruitable stroke work relationship for the heart. With 5 V, 220 microseconds stimulation pulses over a 200 msec contraction period at 60 bpm, the Mprsw increased with stimulation frequencies from 0.055 J/cm at 30 Hz to 0.149 J/cm at 60 Hz, and to 0.212 J/cm at 90 Hz. Stroke work up to 1 J was achieved during muscle shortening of 2.5 cm with forces up to 6 kgf and energy convertor pressure of 112 psi (approximately 760 kPa). This produced an ejected MVAD stroke volume of 40 ml into a systolic pressure of 92 mmHg on a mock loop, at a filling pressure of 10 mmHg. The MVAD is designed as an alternative to cardiac transplantation, to provide completely implantable circulatory support free from batteries and other power conditioning hardware required with electromechanical systems. PMID:8555530

Farrar, D J; Reichenbach, S H; Hill, J D

1994-01-01

78

Frac pack technology still evolving  

SciTech Connect

Success of frac packs depends on candidate selection, treatment design, fluids and proppants, downhole tools, and treatment implementation. Current frac packing techniques have partially evolved from high-permeability stimulation in the Kuparuk field, Alaska. In the Gulf of Mexico (GOM), attempts were made as early as the mid-1960s to hydraulically fracture sands. These early treatments were not highly successful because of techniques, understanding of rock mechanical properties, and poor candidate selection. This article focuses primarily on frac packs in GOM wells, although this technique is also used in South America, Southeast Asia, Pakistan, Nigeria, Alaska, and Europe. Through mid-year 1995 in the GOM alone, there have been over 600 frac packs.

Ebinger, C.D. [Ely and Associates Inc., Houston, TX (United States)

1995-10-23

79

Close-packed poly(methyl methacrylate) nanoparticle arrays-coated polyethylene separators for high-power lithium-ion polymer batteries  

Microsoft Academic Search

In an endeavor to improve the discharge C-rate performance of lithium-ion polymer batteries targeting high-power applications, we develop a novel gel polymer electrolyte-coated separator, which is based on introduction of close-packed poly(methyl methacrylate) (PMMA) nanoparticle arrays onto a polyethylene (PE) separator. In contrast to a conventional PMMA dense coating layer, a noticeable feature of the PMMA nanoparticle array coating layer

Jang-Hoon Park; Woong Park; Jong Hun Kim; Dongjo Ryoo; Hoon Sik Kim; Yeon Uk Jeong; Dong-Won Kim; Sang-Young Lee

2011-01-01

80

HYDRAULIC CONDUCTIVITY OF ESSENTIALLY SATURATED PEAT  

SciTech Connect

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.

Nichols, R

2008-02-27

81

HYDRAULIC POWER TRANSFER SYSTEMS. AGRICULTURAL MACHINERY--SERVICE OCCUPATIONS, MODULE NUMBER 9.  

ERIC Educational Resources Information Center

ONE OF A SERIES DESIGNED TO HELP TEACHERS PREPARE POSTSECONDARY-LEVEL STUDENTS FOR THE AGRICULTURAL MACHINERY SERVICE OCCUPATIONS AS PARTS MEN, MECHANICS, MECHANIC'S HELPERS, AND SERVICE SUPERVISORS, THIS GUIDE AIMS TO DEVELOP STUDENT COMPETENCY IN UNDERSTANDING BASIC HYDRAULICS AND ITS APPLICATION TO AGRICULTURAL MACHINERY. IT WAS DEVELOPED BY A…

Ohio State Univ., Columbus. Center for Vocational and Technical Education.

82

Evaluation of Navigation Receiver Model 700 and Recorder/Power Package Model 700 RP. Make Tracor Evaluatie Navigatie-Ontvanger Model 700 en Recorder/Power Pack Model 700 RP. Fabrikaat: Tracor.  

National Technical Information Service (NTIS)

A technical evaluation was carried out for the navigation receiver model 700 and the recorder/power pack model 700 RP manufactured by Tracor. The receiver operates at 10.2 and 13.6 kHz according to the Omega navigation system. The equipment was found to b...

J. Olk

1973-01-01

83

Method for dense packing discovery  

NASA Astrophysics Data System (ADS)

The problem of packing a system of particles as densely as possible is foundational in the field of discrete geometry and is a powerful model in the material and biological sciences. As packing problems retreat from the reach of solution by analytic constructions, the importance of an efficient numerical method for conducting de novo (from-scratch) searches for dense packings becomes crucial. In this paper, we use the divide and concur framework to develop a general search method for the solution of periodic constraint problems, and we apply it to the discovery of dense periodic packings. An important feature of the method is the integration of the unit-cell parameters with the other packing variables in the definition of the configuration space. The method we present led to previously reported improvements in the densest-known tetrahedron packing. Here, we use the method to reproduce the densest-known lattice sphere packings and the best-known lattice kissing arrangements in up to 14 and 11 dimensions, respectively, providing numerical evidence for their optimality. For nonspherical particles, we report a dense packing of regular four-dimensional simplices with density ?=128/219?0.5845 and with a similar structure to the densest-known tetrahedron packing.

Kallus, Yoav; Elser, Veit; Gravel, Simon

2010-11-01

84

Thermal-hydraulics Analysis of a Radioisotope-powered Mars Hopper Propulsion System  

SciTech Connect

Thermal-hydraulics analyses results produced using a combined suite of computational design and analysis codes are presented for the preliminary design of a concept Radioisotope Thermal Rocket (RTR) propulsion system. Modeling of the transient heating and steady state temperatures of the system is presented. Simulation results for propellant blow down during impulsive operation are also presented. The results from this study validate the feasibility of a practical thermally capacitive RTR propulsion system.

Robert C. O'Brien; Andrew C. Klein; William T. Taitano; Justice Gibson; Brian Myers; Steven D. Howe

2011-02-01

85

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

PubMed Central

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.

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

2014-01-01

86

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

PubMed

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

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

2014-01-01

87

Hydraulic resistance and convective heat transfer within independent power generation micro sources (IPM) channels  

NASA Astrophysics Data System (ADS)

The introduction of new structural materials and technologies contributes to the efficiency increase for the compact IPMs used in various branches of engineering. Use of a driving high-temperature (TIT600K), regenerative (the regeneration ratio is E>85%) micro gas turbine engine ?GTE, major components which are made of structural ceramics, allows not only to maintain the effective efficiency at ?e=26-30%, but, also, sharply reduce the material consumption rate for the micro source as a whole. Application of the laser prototyping technique to manufacture the air heater, which is a part of ?GTE, increases the IPM compactness. Miniaturization of the air heater, manufactured by the structural ceramics laser fusion, can significantly reduce the hydraulic diameter (dh<=1.0 mm) of the channels, designed to transport the working media inside it. Reducing dh leads to a significant increase in the hydraulic resistance of the micro channels. The associated increase in the energy consumption for ?GTE's own needs is compensated by increasing the TIT, E, and heat transfer coefficients in micro channels, and by eliminating the need in cooling for high temperature IPM components.

V, Sudarev A.; V, Sudarev B.; A, Suryaninov A.

2012-05-01

88

Water Power and construction of Complex Hydraulic Works During Fifty Years of Soviet Rule.  

National Technical Information Service (NTIS)

The first section concerns developments and improvements in the construction of hydro plant installations, the manufacture and improvements of the basic power equipment of hydro power plants, and developments in the constructional techniques of hydro stru...

D. M. Yurinov

1978-01-01

89

Packed Bed Reactor Experiment  

NASA Video Gallery

The purpose of the Packed Bed Reactor Experiment in low gravity is to determine how a mixture of gas and liquid flows through a packed bed in reduced gravity. A packed bed consists of a metal pipe ...

90

Production of uniform packing blocks using bag filters  

Microsoft Academic Search

The authors describe a method for intensifying the heat transfer and hydraulic conductivity and, consequently, the overall energy efficiency of a petroleum extraction column by the implementation of bag filters as the packing medium. Diagrams and schematics of the proposed column are presented and test results are cited indicating the high efficiency of the crosscurrent packing design for a wide

K. F. Bogatykh; I. A. Mnushkin

1988-01-01

91

The design and evaluation of a hydraulic-solar powered tracking device  

Microsoft Academic Search

The design and construction of a self-contained heliostat are described. The heliostat operates without external conventional power and with minimal maintenance. The tracking device uses the pressure differential in irradiated sensors to produce the power to align a collector with the sun. Preliminary data suggest that the fluid-mechanical drive system provides adequate accuracy and minimal response time for highly efficient

E. A. Farber; H. A. Ingley; C. A. Morrison; N. Cope

1978-01-01

92

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...

93

Well packing system  

Microsoft Academic Search

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

Drnevich

1990-01-01

94

Evaluating hydraulic losses in FRKDI bag filters  

Microsoft Academic Search

Methods for evaluating and reducing the hydraulic resistance and optimizing the power consumption of FRKDI filters were assessed. Hydraulic losses were calculated by determining local hydraulic resistances along the gas flow from the inlet to the outlet of the filter and summing these values. The hydraulic resistance was at a maximum in the inlet and outlet nozzles. The design variations

Yu. I. Gromov; S. V. Obichkin

1988-01-01

95

Hydraulics Lectures  

NSDL National Science Digital Library

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.

Pytel, Jim

2013-07-18

96

Hydrodynamic and mass transfer characteristic of a novel grid-structured plastic packing  

Microsoft Academic Search

The hydraulic and mass transfer characteristic of a novel grid-structured plastic packing is presented. The geometry of this\\u000a structured packings differ substantially from conventional corrugated structured packings resulting in an open structure which\\u000a enables a free exchange of vapour and liquid also in horizontal direction. The hydraulic performance has been measured by\\u000a air–water experiments in a 440 mm diameter column, the

Markus Lehner; Karin Hoffmann; Werner Geipel

2011-01-01

97

Conversion rates in power plant plumes based on filter pack data. Part II: The oil fired Northport plume  

Microsoft Academic Search

More than 60 airborne plume studies were conducted at a large oil-fired power station during a 3-1\\/2 year period. These studies were conducted to determine the typical rate of formation of sulfate in the plume and the conditions which most influence these atmospheric processes. The power plant chosen for this program is located in the northeast region of the US

R. W. Garber; J. Forrest; L. Newman

2008-01-01

98

Thermal-Hydraulic Analysis of the Nuclear Power Engineering Corporation Containment Experiments with GOTHIC  

Microsoft Academic Search

GOTHIC version 7.0 was used to model five tests that were conducted in the Nuclear Power Engineering Corporation facility in Japan. The tests involved steam and helium injection into a preheated, spray-moderated, 1\\/4-scale model of a pressurized water reactor dry containment. Comparison of GOTHIC predictions to measured data for pressure, vapor temperatures, structure surface temperatures, and helium concentrations provided the

Lawrence E. Wiles; Thomas L George

2003-01-01

99

Investigation of alternate power source for Space Shuttle Orbiter hydraulic system  

NASA Technical Reports Server (NTRS)

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.

Simon, William E.; Young, Fred M.

1993-01-01

100

Investigation of alternate power source for Space Shuttle Orbiter hydraulic system  

NASA Astrophysics Data System (ADS)

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.

Simon, William E.; Young, Fred M.

1993-05-01

101

Portable Hydraulic Powerpack  

NASA Technical Reports Server (NTRS)

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.

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

1986-01-01

102

Carbonization and activation of inexpensive semicoke-packed electrodes to enhance power generation of microbial fuel cells.  

PubMed

A simple and low-cost modification method was developed to improve the power generation performance of inexpensive semicoke electrode in microbial fuel cells (MFCs). After carbonization and activation with water vapor at 800-850?°C, the MFC with the activated coke (modified semicoke) anode produced a maximum power density of 74 Wm(-3) , 17 Wm(-3) , and 681 mWm(-2) (normalized to anodic liquid volume, total reactor volume, and projected membrane surface area, respectively), which was 124 % higher than MFCs using a semicoke anode (33 Wm(-3) , 8 Wm(-3) , and 304 mWm(-2) ). When they were used as biocathode materials, activated coke produced a maximum power density of 177 Wm(-3) , 41 Wm(-3) , and 1628 mWm(-2) (normalized to cathodic liquid volume, total reactor volume, and projected membrane surface area, respectively), which was 211 % higher than that achieved by MFCs using a semicoke cathode (57 Wm(-3) , 13 Wm(-3) , and 524 mWm(-2) ). A substantial increase was also noted in the conductivity, C/O mass ratio, and specific area for activated coke, which reduced the ohmic resistance, increased biomass density, and promoted electron transfer between bacteria and electrode surface. The activated coke anode also produced a higher Coulombic efficiency and chemical oxygen demand removal rate than the semicoke anode. PMID:22639403

Wei, Jincheng; Liang, Peng; Zuo, Kuichang; Cao, Xiaoxin; Huang, Xia

2012-06-01

103

Israelachvili Packing factor  

NSDL National Science Digital Library

Israelachvili Packing factor. The geometry of associated structures depends upon "packing" properties of the molecule: the optimal area of the head group, a0, volume of the chain, V, and the critical length of the tether, lc.

Iacovella, Christopher R.

2006-08-02

104

Two-Phase Flow Studies in Nuclear Power Plant Primary Circuits Using the Three-Dimensional Thermal-Hydraulic Code BAGIRA  

Microsoft Academic Search

in this paper we present recent results of the application of the thermal-hydraulic code BAGIRA to the analysis of complex two-phase flows in nuclear power plants primary loops. In particular, we performed benchmark numerical simulation of an integral LOCA experiment performed on a test facility modeling the primary circuit of VVER-1000. In addition, we have also analyzed the flow patterns

S. D. Kalinichenko; A. E. Kroshilin; V. E. Kroshilin; A. V. Smirnov; P. Kohut

2006-01-01

105

TWO-PHASE FLOW STUDIES IN NUCLEAR POWER PLANT PRIMARY CIRCUITS USING THE THREE-DIMENSIONAL THERMAL-HYDRAULIC CODE BAGIRA  

Microsoft Academic Search

In this paper we present recent results of the application of the thermal-hydraulic code BAGIRA to the analysis of complex two-phase flows in nuclear power plants primary loops. In particular, we performed benchmark numerical simulation of an integral LOCA experiment performed on a test facility modeling the primary circuit of VVER-1000. In addition, we have also analyzed the flow patterns

P. KOHURT; S. D. KALINICHENKO; A. E. KROSHILIN; V. E. KROSHILIN; A. V. SMIRNOV

2006-01-01

106

Variable-Displacement Hydraulic Drive Unit  

NASA Technical Reports Server (NTRS)

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.

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

1986-01-01

107

Analysis of X-33 Linear Aerospike Plume Induced Base-Heating Environment During Power-Pack Out  

NASA Technical Reports Server (NTRS)

The objectives of this viewgraph presentation are to predict the following: (1) dual-engine base-heating at 57% PL at sea level, and (2) dual-engine base-heating during PPO at three ascent abort trajectories. A systematically anchored computational fluid dynamics and heat transfer three-dimensional transfer simulation is being used to study the effect of reduced power levels on base-heating environments during sea level testing and during PPO. Preliminary results show the following: (1) convective heating is higher for the 57% PL than for 100% PL on most of the pillows and flex seals during sea level testing; and (2) convective heating on pillows and flex seals on the 'off' engine side is higher than that on the 'on' engine side.

Wang, Ten-See; Williams, Robert; Droege, Alan; Dagnostino, Mark; Lee, Young-Ching; Douglas, Stan; Turner, James E. (Technical Monitor)

2001-01-01

108

Simulacion hidraulica de los sistemas de una central nuclear para el calculo de cargas en canerias. (Hydraulic simulation of the systems of a nuclear power plant for charges calculation in piping).  

National Technical Information Service (NTIS)

This work presents a general description of the methodology used by the ENACE S.A. Fluids Working Group for hydraulics simulation of a nuclear power plant system for the calculation charges in piping. (Author). (Atomindex citation 23:054231)

N. Masriera

1990-01-01

109

Hydraulics. FOS: Fundamentals of Service.  

ERIC Educational Resources Information Center

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…

John Deere Co., Moline, IL.

110

Charging models & the performance of battery packs for electric bicycles  

Microsoft Academic Search

Electric bicycles are becoming very popular in China in the last several years. 99% of all electric bicycles in China use VRLA battery pack as a power source. The cycle life of most VRLA battery packs is much shorter than a single battery's. In 95% of all failed battery packs, only one battery is dysfunctional. Overcharge and over-discharge are the

Weili Ke; Ning Zhang

2007-01-01

111

Hydraulic Amplifier.  

National Technical Information Service (NTIS)

The proposed hydraulic amplifier differs from those already known for increasing accuracy, simplifying the design and ensuring the independence of the output parameter from a change in pressure and drainage head; the throttle valve in it is incorporated i...

A. A. Lyubimov E. D. Magner M. V. Shevyakov

1969-01-01

112

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.

113

Complex of operations for increasing reliability of hydraulic turbogenerator units of the At-Bashinsk hydroelectric power plant  

Microsoft Academic Search

Vibrational testing conducted on the structure of the room containing the suspension type hydraulic generators is described. Results indicated that a high vibration value (2A-50..mu..) was caused by close coincidence of the frequency of inherent vibrations of the covering of the floor with the frequency of induced vibrations generated by the bearing bases the hydro units - that is, a

V. E. Engel; V. I. Kolen Kolesnikov; A. S. Dolgopolov

1980-01-01

114

Breaker Concentrations Required To Improve the Permeability of Proppant Packs Damaged by Concentrated Linear and Borate-Crosslinked Fracturing Fluids  

Microsoft Academic Search

This paper reports on the concentrations of an oxidative breaker required to reduce significantly the proppant-pack permeability damage caused by aqueous hydraulic fracturing fluids. Long-term, proppant-pack permeability testing was used to evaluate linear and borate-crosslinked gels. Results indicate that increasing the breaker concentration can reduce proppant-pack permeability damage very effectively.

H. D. Brannon; R. J. Pulsinelli

1992-01-01

115

Thermal Hydraulic Performance of Tight Lattice Bundle  

Microsoft Academic Search

Recently, the reduced moderation spectrum BWR has been studied. The fast neutron spectrum is obtained through triangular tight lattice fuel. However, there are few thermal hydraulic test data and thermal hydraulic correlation applicable to critical power prediction in such a tight lattice bundle. This study aims to enhance the database of the thermal hydraulic performance of the tight lattice bundle

Yasushi Yamamoto; Miyuki Akiba; Shinichi Morooka; Kenetsu Shirakawa; Nobuaki Abe

2006-01-01

116

Modelling of Maldistribution in Structured Packings: From Detail to Column Design.  

National Technical Information Service (NTIS)

The aim of the thesis was to determine the origin and extent of both small scale and large scale maldistribution in corrugated sheet structured packings and to develop a complete predictive model for hydraulic and separation performance of industrial scal...

C. F. Stoter

1993-01-01

117

Electrically recharged battery employing a packed/spouted bed metal particle electrode  

DOEpatents

A secondary metal air cell, employing a spouted/packed metal particle bed and an air electrode. More specifically a zinc air cell well suited for use in electric vehicles which is capable of being either electrically or hydraulically recharged.

Siu, Stanley C. (Alameda, CA); Evans, James W. (Piedmont, CA); Salas-Morales, Juan (Berkeley, CA)

1995-01-01

118

Thermal Hydraulic Performance of Tight Lattice Bundle  

NASA Astrophysics Data System (ADS)

Recently, the reduced moderation spectrum BWR has been studied. The fast neutron spectrum is obtained through triangular tight lattice fuel. However, there are few thermal hydraulic test data and thermal hydraulic correlation applicable to critical power prediction in such a tight lattice bundle. This study aims to enhance the database of the thermal hydraulic performance of the tight lattice bundle whose rod gap is about 1mm. Therefore, thermal hydraulic performance measurement tests of tight lattice bundles for the critical power, the pressure drop and the counter current flow limiting were performed. Moreover, the correlations to evaluate the thermal-hydraulic performance of the tight lattice bundle were developed.

Yamamoto, Yasushi; Akiba, Miyuki; Morooka, Shinichi; Shirakawa, Kenetsu; Abe, Nobuaki

119

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

ERIC Educational Resources Information Center

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…

Human Engineering Inst., Cleveland, OH.

120

Hydrodynamics of a packed countercurrent column for the gas extraction  

Microsoft Academic Search

The hydraulic capacity of a countercurrent column with gauze packing was examined at pressures between 8 and 30 MPa and temperatures between 313 and 373 K. The systems used were water + carbon dioxide, aqueous surfactant solution + carbon dioxide, and Toco, a substance whose physical properties are roughly similar to those of α-Tocopherol + carbon dioxide. A distinctive change

Ron Stockfleth; Gerd Brunner

1999-01-01

121

Packed tower distributors tested  

SciTech Connect

Various distributor designs are tested by using a computer model to simulate the liquid flow through a packed bed. The effects of nonhomogeneous liquid flow within the distributor also are studied. The results show the design of the distributor can have a marked effect on the overall efficiency and operation of a packed column. The conclusions are as follows: Every packing has a natural liquid flow distribution. No matter how perfect or imperfect the initial distribution is, the flows will tend toward the natural distribution. Given a deep enough packing bed, the natural distribution will be reached. Perfect distribution will degrade to natural. Maldistribution will improve--sometimes very slowly--to natural. For any real distributor, there is an initial distribution-other than perfect--that will minimize the bed depth required to reach natural distribution. The best drip pan distributor is one that has one drip point for each 10 to 12 pieces of packing in the top layer of packing. The best single spray distributor is one that just reaches the column wall and is as near homogeneous as possible. The best seven-spot multiple spray is a set that overlap and is adjusted so that the column diameter/individual spray diameter (at the packing surface) is about 2.4. Each individual spray must be as homogeneous as possible.

Albright, M.A.

1984-09-01

122

Active (air-cooled) vs. passive (phase change material) thermal management of high power lithium-ion packs: Limitation of temperature rise and uniformity of temperature distribution  

Microsoft Academic Search

The effectiveness of passive cooling by phase change materials (PCM) is compared with that of active (forced air) cooling. Numerical simulations were performed at different discharge rates, operating temperatures and ambient temperatures of a compact Li-ion battery pack suitable for plug-in hybrid electric vehicle (PHEV) propulsion. The results were also compared with experimental results. The PCM cooling mode uses a

Rami Sabbah; R. Kizilel; J. R. Selman; S. Al-Hallaj

2008-01-01

123

Graphitic packing removal tool  

DOEpatents

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.

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

1997-01-01

124

Graphitic packing removal tool  

DOEpatents

Graphitic packing removal tools for removal of the seal rings in one piece are disclosed. 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. 5 figs.

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

1997-11-11

125

Thermal hydraulic calculations to support increase in operating power in McClellen Nuclear Radiation Center(MNRC) TRIGA reactor.  

SciTech Connect

The RELAP5/Mod3.1 computer program has been used to successfully perform thermal-hydraulic analyses to support the Safety Analysis for increasing the MNRC reactor from 1.0 MW to 2.0 MW. The calculation results show the reactor to have operating margin for both the fuel temperature and critical heat flux limits. The calculated maximum fuel temperature of 705 C is well below the 750 C operating limit. The critical heat flux ratio was calculated to be 2.51.

Jensen, R. T.

1998-05-05

126

Solar energy: Packing heat  

NASA Astrophysics Data System (ADS)

Nanoscopic templates functionalized with light-reactive chromophores could ultimately be used to store solar energy and later release it as heat. Now, it has been shown that packing the chromophores together increases both storage capacity and lifetime.

Neale, Nathan R.

2014-05-01

127

Packing Peanut Properties  

NSDL National Science Digital Library

Students work with various types of packing peanuts to investigate states of matter and chemical and physical changes. One of the activities involves making slime. The activities can easily be modified for students with learning disabilities.

Hall, Dori; Hall, Sue

2002-02-02

128

Applying Switched Reluctance Motor to Oil Hydraulic Pump Use  

Microsoft Academic Search

Hydraulic pump units are widely used to operate hydraulic actuators. In a typical machine shop, conventional constant speed hydraulic pump units consume more than 20% of the total electric power necessary to operate CNC machine tools. Most of that energy are wasted to run the axial piston pump at idle. This paper describes a variable speed hydraulic pump unit using

Hiroyuki Yamai; Yuzo Sawada; Kazunobu Ohyama

2004-01-01

129

Tiber winding pack design  

SciTech Connect

A preliminary winding pack design was performed with the goal of showing feasibility of producing 10-T maximum field with a pack current density of 40 A.mm/sup -2/ while accepting 2.7 kW per coil nuclear heating. A cable-in-conduit conductor design (CIC), reported at the 6th Topical Meeting on the Technology of Fusion Energy, was based on several key issues.

Miller, J.R.

1985-08-19

130

Hydraulic Arm Challenge  

NSDL National Science Digital Library

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) 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 design groups must work to communicate effectively through written and verbal communication and sketches.

The Tufts Center For Engineering Educational Outreach

131

Hydraulic drilling machine  

US Patent & Trademark Office Database

A hydraulic drilling machine comprises a drill tool (1) connected to a hydraulic motor (3), a hydraulic percussive mechanism (4) connected via a hydraulic distributor (15) to a hydraulic pressure line (11) and to a hydraulic discharge line (21), and a means (16) for sucking the liquid from the working chamber of the hydraulic percussive mechanism (4) during its idle stroke. The means (16) includes a mixing chamber (17) connected to the discharge line of the hydraulic percussive mechanism, an ejector (18) connected to the discharge line of the hydraulic motor (3), and a diffuser (19) connected to the hydraulic discharge line (21) and accommodating a nozzle of the ejector (18).

1991-04-30

132

Theory of random packings  

NASA Astrophysics Data System (ADS)

We review a recently proposed theory of random packings. We describe the volume fluctuations in jammed matter through a volume function, amenable to analytical and numerical calculations. We combine an extended statistical mechanics approach `a la Edwards' (where the role traditionally played by the energy and temperature in thermal systems is substituted by the volume and compactivity) with a constraint on mechanical stability imposed by the isostatic condition. We show how such approaches can bring results that can be compared to experiments and allow for an exploitation of the statistical mechanics framework. The key result is the use of a relation between the local Voronoi volume of the constituent grains and the number of neighbors in contact that permits a simple combination of the two approaches to develop a theory of random packings. We predict the density of random loose packing (RLP) and random close packing (RCP) in close agreement with experiments and develop a phase diagram of jammed matter that provides a unifying view of the disordered hard sphere packing problem and further shedding light on a diverse spectrum of data, including the RLP state. Theoretical results are well reproduced by numerical simulations that confirm the essential role played by friction in determining both the RLP and RCP limits. Finally we present an extended discussion on the existence of geometrical and mechanical coordination numbers and how to measure both quantities in experiments and computer simulations.

Song, Chaoming; Wang, Ping; Makse, Hernán A.

2010-05-01

133

[Nasal packing and stenting].  

PubMed

Despite nasal packing is not necessary after functional endoscopic sinus surgery according to modern surgical techniques, nasal packing is a necessary tool in ENT. Therefore the state of the art regarding indications, benefit and risk of nasal packing and stents are given. In endonasal surgery only those conventional nasal packing materials should be used--if necessary--which have a smooth surface and minimize mucosal damage, potential worsening of wound healing and negative impact on patient comfort. Modern FESS implicates modern types of nasal packing, which leave the old concept of performing pressure and occupying space. So called hemostatic/resorbable materials are a first step in this direction. But they are critical, because these materials cause increased synechiae and sometimes foreign body reactions because of incorporation into the mucosa. Occlusion of the nose via simple taping of the nasal entrance is a simple and very effective method to create a moist environment to optimize endonasal wound healing or management of a dry nose. Stenting of the frontal sinus is only recommended if it is not possible to realize a sufficiently wide, physiologically formed and in large areas with mucosa covered frontal sinus outflow tract. PMID:19353455

Weber, R K

2009-05-01

134

TWO-PHASE FLOW STUDIES IN NUCLEAR POWER PLANT PRIMARY CIRCUITS USING THE THREE-DIMENSIONAL THERMAL-HYDRAULIC CODE BAGIRA.  

SciTech Connect

In this paper we present recent results of the application of the thermal-hydraulic code BAGIRA to the analysis of complex two-phase flows in nuclear power plants primary loops. In particular, we performed benchmark numerical simulation of an integral LOCA experiment performed on a test facility modeling the primary circuit of VVER-1000. In addition, we have also analyzed the flow patterns in the VVER-1000 steam generator vessel for stationary and transient operation regimes. For both of these experiments we have compared the numerical results with measured data. Finally, we demonstrate the capabilities of BAGIRA by modeling a hypothetical severe accident for a VVER-1000 type nuclear reactor. The numerical analysis, which modeled all stages of the hypothetical severe accident up to the complete ablation of the reactor cavity bottom, shows the importance of multi-dimensional flow effects.

KOHURT, P. (BNL), KALINICHENKO, S.D.; KROSHILIN, A.E.; KROSHILIN, V.E.; SMIRNOV, A.V.

2006-06-04

135

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)

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.

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

2014-05-01

136

Frac packs: A specialty option or primary completion technique?  

SciTech Connect

High permeability fracture treatments have taken place at Alaska`s North Slope, in the North Sea, and most recently, in the unconsolidated Miocene formations of the Gulf of Mexico -- where gravel pack completions have historically been used to prevent sand production. In the Gulf of Mexico, attempts were made as early as the mid-1960s to hydraulically fracture sands. However, some of these early treatments failed because of improper techniques, poor candidate selection and lack of understanding of rock property mechanics. Recent developments in fracturing technology, and the use of this technology to fracture through damage has achieved more favorable results than gravel packing and sandstone acidizing, and has led to widespread use of these fracture treatments. The procedure for fracturing high permeability formations is called frac packing. These frac pack treatments are typically used to remove near-wellbore damage that occurs from drilling and completion operations.

NONE

1997-03-01

137

Physico-chemical characterization of mortars as a tool in studying specific hydraulic components: application to the study of ancient Naxos aqueduct  

NASA Astrophysics Data System (ADS)

Mortars and plasters from the ancient aqueduct on the island of Naxos, Greece, were studied with regard to mineralogical and chemical composition, grain size distribution, raw materials and hydraulic properties, in order to assess their characteristics and design compatible repair mortars. The authentic materials contained lime, crushed-brick, siliceous and calcitic aggregates, in different proportions according to mortar type. Crushed-bricks fired at low temperatures and lightweight volcanic aggregates contained amorphous phases, which upon reaction with lime yielded hydraulic components capable of protecting the construction from the continuous presence of water. Hydraulic calcium silicate/aluminate hydrates, the proportions and the perfect packing of the raw materials, along with the diligent application justify the longevity and durability of the studied samples. The hydraulic properties of samples were pointed out through (a) the well-established CO2/H2O ratio derived from the thermogravimetric analysis and (b) by introducing two powerful indices issued from the chemical analysis, namely CaOhydr and soluble SiO2 hydr. These indices improved the clustering of hydraulic mortars and provided better correlation between mortars, plasters and their binders. By comparing grain size distribution and hydraulicity indices it was possible to distinguish among the construction phases. Based on this study, repair mortars were formulated by hydraulic lime, siliceous sand, calcareous and crushed-brick aggregates, with the optimal water content, ensuring optimum workability and compatible appearance with the authentic ones.

Maravelaki-Kalaitzaki, P.; Galanos, A.; Doganis, I.; Kallithrakas-Kontos, N.

2011-07-01

138

Power Capability Investigation Based on Electrothermal Models of Press-Pack IGBT Three-Level NPC and ANPC VSCs for Multimegawatt Wind Turbines  

Microsoft Academic Search

Wind turbine power capability is an essential set of data for both wind turbine manufacturers\\/operators and transmission system operators since the power capability determines whether a wind turbine is able to fulfill transmission system reactive power requirements and how much it is able to provide reactive power support as an ancillary service. For multimegawatt full-scale wind turbines, power capability depends

Osman S. Senturk; Lars Helle; Stig Munk-Nielsen; Pedro Rodriguez; Remus Teodorescu

2012-01-01

139

New Bounds for Multi-Dimensional Packing.  

National Technical Information Service (NTIS)

New upper and lower bounds are presented for a multi-dimensional generalization of bin packing called box packing. Several variants of this problem, including bounded space box packing, square packing, variable sized box packing and resource augmented box...

R. Van Stee S. Seiden

2001-01-01

140

Hydraulic borehole mining system  

SciTech Connect

A hydraulic underground mining system is disclosed for operating through a small diameter borehole into a subterranean body. An elongated mining tool includes a liquid jet nozzle that is movable in vertical direction along the length of the mining tool for forming a directed jet stream to impact material in the ore body and convert the material into a slurry. An orifice is positioned below the jet so that slurry flows into the orifice, the latter being connected to a jet pump which returns generated slurry to the surface. Suitable hydraulic power means are provided for operating the jet pump and for moving the jet stream in vertical and circular directions. Means for monitoring and controlling the progress of mining and the condition of components of the system are provided to monitor and control the system from a centralized location.

Archibald, W.R.

1983-08-30

141

Gravel pack method  

Microsoft Academic Search

This completion method can be performed in the following sequence: (1) deforming the formation by injecting a fluid therein to form a cavity adjacent the well bore; and (2) pressure packing the cavity with an aggregate to further displace the formation outward, the aggregate being graded to form an outer sand exclusion zone and an inner high permeability zone. In

D. B. Wood; O. M. Kiel

1972-01-01

142

Packing Steiner trees  

Microsoft Academic Search

The Steiner packing problem is to find the maximum number of edge-disjoint subgraphs of a given graph G that connect a given set of required points S. This problem is motivated by practical applications in VLSI- layout and broadcasting, as well as theoretical reasons. In this paper, we study this problem and present an algorithm with an asymptotic approximation factor

Kamal Jain; Mohammad Mahdian; Mohammad R. Salavatipour

2003-01-01

143

Packing Directed Circuits Fractionally  

Microsoft Academic Search

LetG be a digraph, and letk=1, such that no “fractional” packing of directed circuits ofG has value >k, when every vertex is given “capacity” 1. We prove there is a set ofO (k logk logk) vertices meeting all directed circuits ofG.

Paul D. Seymour

1995-01-01

144

Find Your Pack  

NSDL National Science Digital Library

This activity introduces learners to wolf behavior and communication. Learners explore how wolves communicate with each other by using their sense of smell to identify members of their "pack." Activity also includes suggestions for connecting this activity to a discussion of how habitat loss can affect wolf populations.

Eduweb; Zoo, Minnesota

2012-01-01

145

46 CFR 112.50-3 - Hydraulic starting.  

Code of Federal Regulations, 2010 CFR

...POWER SYSTEMS Emergency Diesel and Gas Turbine Engine Driven Generator Sets § 112.50-3 Hydraulic starting...that provides the cranking torque and engine starting RPM recommended by the engine manufacturer. The hydraulic...

2009-10-01

146

46 CFR 112.50-3 - Hydraulic starting.  

Code of Federal Regulations, 2010 CFR

...POWER SYSTEMS Emergency Diesel and Gas Turbine Engine Driven Generator Sets § 112.50-3 Hydraulic starting...that provides the cranking torque and engine starting RPM recommended by the engine manufacturer. The hydraulic...

2010-10-01

147

46 CFR 112.50-3 - Hydraulic starting.  

Code of Federal Regulations, 2013 CFR

...OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING EMERGENCY LIGHTING AND POWER SYSTEMS Emergency Diesel and Gas Turbine Engine Driven Generator Sets § 112.50-3 Hydraulic starting. A hydraulic starting system must meet the...

2013-10-01

148

Hydraulic fracturing-1  

SciTech Connect

This book contains papers on hydraulic fracturing. Topics covered include: An overview of recent advances in hydraulic fracturing technology; Containment of massive hydraulic fracture; and Fracturing with a high-strength proppant.

Not Available

1990-01-01

149

Relating Relative Hydraulic Conductivity and Electrical Conductivity in the Unsaturated Zone  

NASA Astrophysics Data System (ADS)

Monitoring flow in the unsaturated zone is an important task, especially for overseeing managed aquifer recharge, tracking contaminant transport, and optimizing agricultural operations. Geophysical data can provide in-situ unsaturated subsurface information with much higher temporal and spatial resolution over a larger areal extent than traditional hydrologic methods. The measurement of electrical conductivity is a geophysical technique of particular interest in the vadose zone because the geophysical parameter that is obtained is highly correlated with saturation. Changes in saturation can then be used to make qualitative inferences on the rate of fluid motion within the unsaturated zone. However, quantitative information on infiltration rates and unsaturated flow rates via saturation is typically hard to find and usually requires a cumbersome hydrologic inversion that cannot be done in real-time. In this work, we used numerical simulations to find a relationship that relates electrical conductivity not to saturation, but to relative hydraulic conductivity, which has been shown to be a useful proxy for direct estimation of infiltration and unsaturated flow rates even under transient conditions. We obtained this relationship through numerical modeling by generating pore-scale soil structures, partially saturating them through morphological operations according to both wetting and draining schemes and calculating their hydraulic and electrical conductivities at a range of saturations. We found that a power law relationship exists between relative hydraulic conductivity (hydraulic conductivity divided by saturated conductivity) and relative electrical conductivity for each of the sixteen tested media. The power law exponent in the relationship changes depending on whether the medium is being wetted or drained as would be expected as hysteresis is evident in both unsaturated hydraulic and electrical conductivity. Parameters that are typically seen to be related to both saturated conductivities, such as tortuosity, porosity and surface area to volume ratio were calculated for each sphere pack and plotted against the exponent. No correlation was seen between the exponent and these parameters for either the wetting or draining curves. However, the exponent was well constrained for the wetting curve to between 2.45 and 3 and the draining curve to between 1.6 and 2.2. The error introduced by using values within these bounds to estimate the hydraulic conductivity of any of the numerical soil packs using electrical conductivity was negligible, meaning that mean values of 2.75 and 1.8 could be used to estimate the hydraulic conductivity for any pack. These results are applicable to media with minimal surface conduction. We went on to analyze the effects of surface conduction via mineralogy and clay on the power law relationship between electrical and hydraulic conductivity via a number of approaches. We found that the power law relationship between hydraulic and electrical conductivity breaks down when clay content exceeds 5%. However, for media with less clay, use of the relationship with the mean values for exponents found for the clean medium results in less than ten percent error.

Mawer, C. M.; Knight, R. J.; Kitanidis, P. K.

2013-12-01

150

Flooding characteristics of Goodloe packing  

Microsoft Academic Search

Experimental flooding data for the countercurrent flow of air and water in a 7.62-cm-diam glass column filled with Goodloe packing were compared with a correlation reported by the packing manufacturer. Flooding rates observed in this study were as low as one-half those predicted by the correlation. Rearranging the packing by inverting the column and removing some packing segments yielded results

J. M. Begovich; J. S. Watson

1976-01-01

151

Investigation into Hydraulic Gear Pump Efficiencies during the First Few Hours of the Pumps' Lives and a Comparative Study of Accelerated Life Test Methods on Hydraulic Fluid Power Gear Pumps. Parts 1 and 2.  

National Technical Information Service (NTIS)

This interim report summarizes the results obtained in evaluating the changes in overall efficiency of 18 hydraulic gear pumps during the first few hours of the pumps' lives, that is, during the break-in period. A literature search and a mail survey of in...

1979-01-01

152

Packing fraction of geometric random packings of discretely sized particles  

NASA Astrophysics Data System (ADS)

The packing fraction of geometric random packings of discretely sized particles is addressed in the present paper. In an earlier paper [Brouwers, Phys. Rev. EPLEEE81063-651X10.1103/PhysRevE.74.031309 74, 031309 (2006); Brouwers, Phys. Rev. EPLEEE81063-651X10.1103/PhysRevE.74.069901 74, 069901(E) (2006)], analytical solutions were presented for the packing fraction of polydisperse geometric packings for discretely sized particles with infinitely large size ratio and the packing of continuously sized particles. Here the packing of discretely sized particles with finite size ratio u is analyzed and compared with empirical data concerning five ternary geometric random close packings of spheres with a size ratio of 2, yielding good agreement.

Brouwers, H. J. H.

2011-10-01

153

95. BUILDING NO. 539, SMALL ARMS POWDER BLENDER AND PACKING ...  

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

95. BUILDING NO. 539, SMALL ARMS POWDER BLENDER AND PACKING HOUSE, LOOKING SOUTHEAST AT NORTHWEST ELEVATION FROM NORTH SHORE OF PICATINNY LAKE. - Picatinny Arsenal, 500 Area, Powder Factory & Power House, State Route 15 near I-80, Dover, Morris County, NJ

154

97. BUILDING NO. 539, SMALL ARMS POWDER BLENDER AND PACKING ...  

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

97. BUILDING NO. 539, SMALL ARMS POWDER BLENDER AND PACKING HOUSE, LOOKING NORTH AT SOUTHEAST ELEVATION. - Picatinny Arsenal, 500 Area, Powder Factory & Power House, State Route 15 near I-80, Dover, Morris County, NJ

155

Random Very Loose Packings  

NASA Astrophysics Data System (ADS)

We measure the number ?(?) of mechanically stable states of volume fraction ? of a granular assembly under gravity. The granular entropy S(?)=log??(?) vanishes both at high density, at ???rcp, and a low density, at ???rvlp, where ?rvlp is a new lower bound we call random very loose pack. ?rlp is the volume fraction where the entropy is maximal. These findings allow for a clear explanation of compaction experiments and provide the first first-principle definition of the random loose volume fraction. In the context of the statistical mechanics approach to static granular materials, states with ?

Ciamarra, Massimo Pica; Coniglio, Antonio

2008-09-01

156

Optimal configuration design for hydraulic split hybrid vehicles  

Microsoft Academic Search

Hydraulic hybrid vehicles are more suitable for heavy-duty applications in urban driving than hybrid electric vehicles because of the high power density and low cost of hydraulic devices. However, the low rotational speeds of hydraulic pump\\/motor and the low energy density of the accumulator impose severe constraints on the design and control for these vehicles. The split configuration is an

Chiao-Ting Li; Huei Peng

2010-01-01

157

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

Microsoft Academic Search

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,

N. Barbieri; A. H. M. Santos

1999-01-01

158

Hydraulic well pumping apparatus  

SciTech Connect

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.

Wright, C.P.

1987-03-03

159

BWR 9 X 9 Fuel Assembly Thermal-Hydraulic Tests (2): Hydraulic Vibration Test  

SciTech Connect

Nuclear Power Engineering Corporation (NUPEC) conducted thermal-hydraulic projects for verification of thermal-hydraulic design reliability for BWR high-burnup 8 x 8 and 9 x 9 fuel assemblies, entrusted by the Ministry of Economy, Trade and Industry (METI). As a part of the NUPEC thermal-hydraulic projects, hydraulic vibration tests using full-scale test assemblies simulating 9 x 9 fuel assemblies were carried out to evaluate BWR fuel integrity. The test data were applied to development of a new correlation for the estimation of fuel rod vibration amplitude. (authors)

Yoshiaki Tsukuda; Katsuichiro Kamimura; Toshiitsu Hattori [Nuclear Power Engineering Corporation, 17-1 Toranomon 3-chome, Minato-ku, Tokyo 105-0001 (Japan); Akira Tanabe [Global Nuclear Fuel-Japan Co., Ltd., Tokyo (Japan); Noboru Saito; Masahiko Warashina [Toshiba Corporation (Japan); Yuji Nishino [Nuclear Fuel Industries Ltd. (Japan)

2002-07-01

160

Packing Products: Polystyrene vs. Cornstarch  

ERIC Educational Resources Information Center

Packing materials such as polystyrene take thousands of years to decompose, whereas packing peanuts made from cornstarch, which some companies are now using, can serve the same purpose, but dissolve in water. The author illustrates this point to her class one rainy day using the sculptures students made from polystyrene and with the cornstarch…

Starr, Suzanne

2009-01-01

161

Flooding Characteristics of Goodloe Packing.  

National Technical Information Service (NTIS)

Experimental flooding data for the countercurrent flow of air and water in a 7.62-cm-diam glass column filled with Goodloe packing were compared with a correlation reported by the packing manufacturer. Flooding rates observed in this study were as low as ...

J. M. Begovich J. S. Watson

1976-01-01

162

Packed Planetary Systems  

NASA Astrophysics Data System (ADS)

Planetary systems display a wide range of appearances, with apparently arbitrary values of semi-major axis, eccentricity, etc. We reduce the complexity of orbital configurations to a single value, ? , which is a measure of how close, over secular timescales ( ˜10,000 orbits), two consecutive planets come to each other. We measure this distance relative to the sum of the radii of their Hill spheres, sometimes referred to as mutual Hill radii (MHR). We determine the closest approach distance by numerically integrating the entire system on coplanar orbits, using minimum masses. For non-resonant systems, close approach occurs during apsidal alignment, either parallel or anti-parallel. For resonant pairs the distance at conjunction determines the closest approach distance. Previous analytic work found that planets on circular orbits were assuredly unstable if they came within 3.5 MHR (i.e. Gladman 1993; Chambers, Wetherill & Boss 1996). We find that most known pairs of jovian planets (including those in our solar system) come within 3.5 -- 7 MHR of each other. We also find that several systems are unstable (their closest approach distance is less than 3.5 MHR). These systems, if they are real, probably exist in an observationally permitted location somewhat different from the current best fit. In these cases, the planets' closest approach distance will most likely also be slightly larger than 3.5 MHR. Most pairs beyond 7 MHR probably experienced post-formation migration (i.e. tidal circularization, inward scattering of small bodies) which moved them further apart. This result is even more remarkable since we have used the minimum masses; most likely the systems are inclined to the line of sight, making the Hill spheres larger, and shrinking ? . This dense packing may reflect a tendency for planets to form as close together as they can without being dynamically unstable. This result further implies there may be a large number of smaller, currently undetectable companions packed in orbits around stars with known planets.

Barnes, R.; Greenberg, R.

2005-08-01

163

Piezoelectric hydraulic pump  

NASA Astrophysics Data System (ADS)

A hybrid piezohydraulic pump is under development for smart structures applications. Structural control applications often require large force be delivered over a large displacement. Piezoelectric actuators produce a large force over a small displacement. This can be repeated many times per second. Step and repeat piezoelectric devices, such as inchworm motors, increase the power output of the actuators and have the potential to produce large forces and large displacements simultaneously. The piezohydraulic pump makes use of the step and repeat capability. The pump utilizes a piezoelectric stack actuator to drive a piston in a cylinder. The forward stroke pressurizes the hydraulic fluid in the cylinder and forces it out through a check valve. The reverse stroke draws fluid into the cylinder through a second check valve. The prototype pump has produced a working pressure of 6.9 MPa (1000 psi) and a flow rate of 45 ccm.

Mauck, Lisa D.; Lynch, Christopher S.

1999-06-01

164

Piezoelectric hydraulic pump performance  

NASA Astrophysics Data System (ADS)

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.

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

2001-06-01

165

Nasal packing after septoplasty: a randomized comparison of packing versus no packing in 88 patients.  

PubMed

The once-common practice of packing the nose after septoplasty was based on a desire to prevent postoperative complications such as bleeding, septal hematoma, and adhesion formation. However, it was since found that not only is nasal packing ineffective in this regard, it can actually cause these complications. Although the consensus in the world literature is that packing should be avoided, to the best of our knowledge, no truly randomized study has been undertaken in Southwest Asia upon which to justify this recommendation here. Therefore, we conducted a prospective randomized comparison of the incidence of a variety of postoperative signs and symptoms in 88 patients, 15 years of age and older, who did (n = 44) and did not (n = 44) undergo nasal packing following septoplasty. We found that the patients who underwent packing experienced significantly more postoperative pain, headache, epiphora, dysphagia, and sleep disturbance on the night of surgery. Oral and nasal examinations 7 days postoperatively revealed no significant difference between the two groups in the incidence of bleeding, septal hematoma, adhesion formation, and local infection. Finally, the packing group reported a moderate to high level of pain during removal of the packing. Our findings confirm that nasal packing after septoplasty is not only unnecessary, it is actually a source of patient discomfort and other signs and symptoms. PMID:19006062

Awan, Mohammad Sohail; Iqbal, Moghira

2008-11-01

166

Characterization of Ankara meat packing plant wastewater and treatment with a rotating biological contactor  

Microsoft Academic Search

The general characteristics of Ankara Meat Packing Plant wastewater have been determined by taking samples and analyzing them. Also, treatability of wastewater from the plant has been studied at different hydraulic and organic loading rates by using a rotating biological contactor (RBC). The experimental results showed that the channel where wastewater of the slaughtering unit is discharged has a higher

Mustafa O?uz; Meral O?uz

1993-01-01

167

Experiment and modeling to evaluate the effects of proppant-pack diagenesis on fracture treatments  

Microsoft Academic Search

Observed reductions in the permeability of propped hydraulic fractures are examined by considering the role of mechanical stresses and the chemistry of pore fluids at elevated temperatures as agents of proppant diagenesis. Stress-enhanced dissolution of proppant increases the density of grain packing and reprecipitation of mineral matter further occludes pores — together these mechanisms additively reduce porosity and permeability. Experiments

Dae Sung Lee; Derek Elsworth; Hideaki Yasuhara; Jim D. Weaver; Richard Rickman

2010-01-01

168

Valve stem and packing assembly  

DOEpatents

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.

Wordin, J.J.

1991-09-03

169

Valve stem and packing assembly  

DOEpatents

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.

Wordin, John J. (Bingham County, ID)

1991-01-01

170

Dense periodic packings of tori  

NASA Astrophysics Data System (ADS)

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.

Gabbrielli, Ruggero; Jiao, Yang; Torquato, Salvatore

2014-02-01

171

Theory and applications of drilling fluid hydraulics  

SciTech Connect

A reference on drilling fluid hydraulics, this text provides information, nomenclature and equations. Chapter 1 introduces the basic principles of fluid properties. Chapter 2 discusses the general principles, models and measurements related to fluid flow. Newtonian, Bingham, Power Law, Casson, Robertson-Stiff and Herschel-Bulkley models are all discussed. Chapters 3 through 10 analyze hydraulic problems specific to drilling fluids and the drilling process including: viscometric measurements, pressure losses, swab and surge pressures, cuttings transport, and hydraulics optimization. Each chapter concludes with a bibliography. For consistency, nomenclature remains constant and SI units are used throughout the text. All key equations using oilfield units are listed in the appendices.

Whittaker, A.

1985-01-01

172

Hydraulic Model Studies of the Forebay Reservoir Inlet-Outlet Structure for Mt. Elbert Pumped-Storage Power plant, Fryingpan-Arkansas Project, Colorado.  

National Technical Information Service (NTIS)

Hydraulic model studies were performed to assure satisfactory flow conditions through the forebay reservoir inlet-outlet structure for Mt. Elbert Pumped-Storage Powerplant, Colorado. The main purpose for the studies was to develop a design to provide a un...

P. L. Johnson

1972-01-01

173

Performance Analysis of 'Star' Pack Cushion Inserts.  

National Technical Information Service (NTIS)

The objectives of the study were two-fold: (1) Modify 'Star' pack cushion inserts to provide more uniform cushioning protection and most cost effective pack; and (2) determine adequacy of previously published 'Star' pack performance data for representing ...

R. V. Brown

1974-01-01

174

Method for packing chromatographic beds  

DOEpatents

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.

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

1991-01-01

175

PackBot: a versatile platform for military robotics  

NASA Astrophysics Data System (ADS)

The iRobot PackBot is a combat-tested, man-portable UGV that has been deployed in Afghanistan and Iraq. The PackBot is also a versatile platform for mobile robotics research and development that supports a wide range of payloads suitable for many different mission types. In this paper, we describe four R&D projects that developed experimental payloads and software using the PackBot platform. CHARS was a rapid development project to develop a chemical/radiation sensor for the PackBot. We developed the CHARS payload in six weeks and deployed it to Iraq to search for chemical and nuclear weapons. Griffon was a research project to develop a flying PackBot that combined the capabilities of a UGV and a UAV. We developed a Griffon prototype equipped with a steerable parafoil and gasoline-powered motor, and we completed successful flight tests including remote-controlled launch, ascent, cruising, descent, and landing. Valkyrie is an ongoing research and development project to develop a PackBot payload that will assist medics in retrieving casualties from the battlefield. Wayfarer is an applied research project to develop autonomous urban navigation capabilities for the PackBot using laser, stereo vision, GPS, and INS sensors.

Yamauchi, Brian M.

2004-09-01

176

Regular Packings on Periodic Lattices  

NASA Astrophysics Data System (ADS)

We investigate the problem of packing identical hard objects on regular lattices in d dimensions. Restricting configuration space to parallel alignment of the objects, we study the densest packing at a given aspect ratio X. For rectangles and ellipses on the square lattice as well as for biaxial ellipsoids on a simple cubic lattice, we calculate the maximum packing fraction ?d(X). It is proved to be continuous with an infinite number of singular points X?min?,X?max?, ?=0,±1,±2,…. In two dimensions, all maxima have the same height, whereas there is a unique global maximum for the case of ellipsoids. The form of ?d(X) is discussed in the context of geometrical frustration effects, transitions in the contact numbers, and number-theoretical properties. Implications and generalizations for more general packing problems are outlined.

Ras, Tadeus; Schilling, Rolf; Weigel, Martin

2011-11-01

177

Regular packings on periodic lattices.  

PubMed

We investigate the problem of packing identical hard objects on regular lattices in d dimensions. Restricting configuration space to parallel alignment of the objects, we study the densest packing at a given aspect ratio X. For rectangles and ellipses on the square lattice as well as for biaxial ellipsoids on a simple cubic lattice, we calculate the maximum packing fraction ?(d)(X). It is proved to be continuous with an infinite number of singular points X(?)(min), X(?)(max), ? = 0, ±1, ±2,…. In two dimensions, all maxima have the same height, whereas there is a unique global maximum for the case of ellipsoids. The form of ?(d)(X) is discussed in the context of geometrical frustration effects, transitions in the contact numbers, and number-theoretical properties. Implications and generalizations for more general packing problems are outlined. PMID:22181895

Ras, Tadeus; Schilling, Rolf; Weigel, Martin

2011-11-18

178

On packing R-trees  

Microsoft Academic Search

We propose new R-tree packing techniques for static databases. Given a collection of rectangles, we sort them and build the R-tree bottom-up. There are several ways to sort the rectangles; the innovation of this work is the use of fractals, and specifically the hilbert curve, to achieve better ordering of the rectangles and eventually better pack- ing. We proposed and

Ibrahim Kamel; Christos Faloutsos

1993-01-01

179

Frac-and-pack stimulation: Application, design, and field experience  

SciTech Connect

This paper discusses the criteria for selecting wells to be frac-and-packed. The authors show how systematic study of the inflow performance can be used to assess the potential of frac-and-packed wells, to identify the controlling factors, and to optimize design parameters. They also show that fracture conductivity is often the key to successful treatment. This conductivity depends largely on proppant size; formation permeability damage around the created fracture has less effect. Appropriate allowance needs to be made for flow restrictions caused by the presence of the perforations, partial penetration, and non-Darcy effects. They describe the application of the overpressure-calibrated hydraulic fracture model in frac-and-pack treatment design, and discuss some operational considerations with reference to field examples. The full potential of this promising new completion method can be achieved only if the design is tailored to the individual well. This demands high-quality input data, which can be obtained only from a calibration test. This paper presents their strategy for frac-and-pack design, drawing on examples from field experience. They also point out several areas that the industry needs to address, such as the sizing of proppant in soft formations and the interaction between fracturing fluids and resin in resin-coated proppant.

Roodhart, L.P.; Fokker, P.A.; Davies, D.R.; Shlyapobersky, J.; Wong, G.K.

1994-03-01

180

Are proteins well-packed?  

PubMed Central

The average packing density inside proteins is as high as in crystalline solids. Does this mean proteins are well-packed? We go beyond average densities, and look at the full distribution functions of free volumes inside proteins. Using a new and rigorous Delaunay triangulation method for parsing space into empty and filled regions, we introduce formal definitions of interior and surface packing densities. Although proteins look like organic crystals by the criterion of average density, they look more like liquids and glasses by the criterion of their free volume distributions. The distributions are broad, and the scalings of volume-to-surface, volume-to-cluster-radius, and numbers of void versus volume show that the interiors of proteins are more like randomly packed spheres near their percolation threshold than like jigsaw puzzles. We find that larger proteins are packed more loosely than smaller proteins. And we find that the enthalpies of folding (per amino acid) are independent of the packing density of a protein, indicating that van der Waals interactions are not a dominant component of the folding forces.

Liang, J; Dill, K A

2001-01-01

181

MICROBIAL TRANSPORT THROUGH POROUS MEDIA; THE EFFECTS OF HYDRAULIC CONDUCTIVITY AND INJECTION VELOCITY. (R825513C019)  

EPA Science Inventory

The effects of hydraulic conductivity and injection velocity on microbial transport through porous media were investigated. Glass chromatography columns were packed separately with clean quartz sand of two diameters (0.368mm or 0.24O mm) and two hydraulic conductivities (1.37&...

182

Enabling Microliquid Chromatography by Microbead Packing of Microchannels  

NASA Technical Reports Server (NTRS)

The microbead packing is the critical element required in the success of on-chip microfabrication of critical microfluidic components for in-situ analysis and detection of chiral amino acids. In order for microliquid chromatography to occur, there must be a stationary phase medium within the microchannel that interacts with the analytes present within flowing fluid. The stationary phase media are the microbeads packed by the process discussed in this work. The purpose of the microliquid chromatography is to provide a lightweight, low-volume, and low-power element to separate amino acids and their chiral partners efficiently to understand better the origin of life. In order to densely pack microbeads into the microchannels, a liquid slurry of microbeads was created. Microbeads were extracted from a commercially available high-performance liquid chromatography column. The silica beads extracted were 5 microns in diameter, and had surface coating of phenyl-hexyl. These microbeads were mixed with a 200- proof ethanol solution to create a microbead slurry with the right viscosity for packing. A microfilter is placed at the outlet via of the microchannel and the slurry is injected, then withdrawn across a filter using modified syringes. After each injection, the channel is flushed with ethanol to enhance packing. This cycle is repeated numerous times to allow for a tightly packed channel of microbeads. Typical microbead packing occurs in the macroscale into tubes or channels by using highly pressurized systems. Moreover, these channels are typically long and straight without any turns or curves. On the other hand, this method of microbead packing is completed within a microchannel 75 micrometers in diameter. Moreover, the microbead packing is completed into a serpentine type microchannel, such that it maximizes microchannel length within a microchip. Doing so enhances the interactions of the analytes with the microbeads to separate efficiently amino acids and amino acid enantiomers.

Balvin, Manuel; Zheng, Yun

2014-01-01

183

Enabling Microliquid Chromatography by Microbead Packing of Microchannels  

NASA Technical Reports Server (NTRS)

The microbead packing is the critical element required in the success of on-chip microfabrication of critical microfluidic components for in-situ analysis and detection of chiral amino acids. In order for microliquid chromatography to occur, there must be a stationary phase medium within the microchannel that interacts with the analytes present within flowing fluid. The stationary phase media are the microbeads packed by the process discussed in this work. The purpose of the microliquid chromatography is to provide a lightweight, low-volume, and low-power element to separate amino acids and their chiral partners efficiently to understand better the origin of life. In order to densely pack microbeads into the microchannels, a liquid slurry of microbeads was created. Microbeads were extracted from a commercially available high-performance liquid chromatography column. The silica beads extracted were 5 microns in diameter, and had surface coating of phenyl-hexyl. These microbeads were mixed with a 200- proof ethanol solution to create a microbead slurry with the right viscosity for packing. A microfilter is placed at the outlet via of the microchannel and the slurry is injected, then withdrawn across a filter using modified syringes. After each injection, the channel is flushed with ethanol to enhance packing. This cycle is repeated numerous times to allow for a tightly packed channel of microbeads. Typical microbead packing occurs in the macroscale into tubes or channels by using highly pressurized systems. Moreover, these channels are typically long and straight without any turns or curves. On the other hand, this method of microbead packing is completed within a microchannel 75 micrometers in diameter. Moreover, the microbead packing is completed into a serpentine type microchannel, such that it maximizes microchannel length within a microchip. Doing so enhances the interactions of the analytes with the microbeads to separate efficiently amino acids and amino acid enantiomers.

Balvin, Manuel; Zheng, Yun

2013-01-01

184

Thermally Actuated Hydraulic Pumps  

NASA Technical Reports Server (NTRS)

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.

Jones, Jack; Ross, Ronald; Chao, Yi

2008-01-01

185

Disc pack cleaning table saves computer time  

NASA Technical Reports Server (NTRS)

Disc pack holding table is support frame upon which computer disc pack is loaded and protective cover released. This combination permits manual off-line cleaning of disc pack storage units at any time without shutting down the computer, and eliminates on-line disc drive unit to hold pack during cleaning.

Guy, J. T., Sr.

1970-01-01

186

Thermal hydraulic tests for reactor safety system -Research on the improvement of nuclear safety-.  

National Technical Information Service (NTIS)

The present research aims at the development of the thermal hydraulic verification test technology for the reactor safety system of the conventional and advanced nuclear power plant and the development of the advanced thermal hydraulic measuring technique...

M. K. Chung C. K. Park S. K. Yang C. H. Chung S. Y. Chun

1994-01-01

187

Hydraulic hoisting and backfilling  

Microsoft Academic Search

In a country such as South Africa, with its large deep level mining industry, improvements in mining and hoisting techniques could result in substantial savings. Hoisting techniques, for example, may be improved by the introduction of hydraulic hoisting. The following are some of the advantages of hydraulic hoisting as against conventional skip hoisting: (1) smaller shafts are required because the

H. B. Sauermann

1982-01-01

188

Downhole hydraulic seismic generator  

DOEpatents

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.

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

1992-01-01

189

Sleeping distance in wild wolf packs  

USGS Publications Warehouse

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.

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

1980-01-01

190

[Electroflotation packing of mycelial wastes].  

PubMed

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

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

1989-04-01

191

Packing microstructure and local density variations of experimental and computational pebble beds  

SciTech Connect

In pebble bed type nuclear reactors the fuel is contained in graphite pebbles, which form a randomly stacked bed with a non-uniform packing density. These variations can influence local coolant flow and power density and are a possible cause of hotspots. To analyse local density variations computational methods are needed that can generate randomly stacked pebble beds with a realistic packing structure on a pebble-to-pebble level. We first compare various properties of the local packing structure of a computed bed with those of an image made using computer aided X-ray tomography, looking at properties in the bulk of the bed and near the wall separately. Especially for the bulk of the bed, properties of the computed bed show good comparison with the scanned bed and with literature, giving confidence our method generates beds with realistic packing microstructure. Results also show the packing structure is different near the wall than in the bulk of the bed, with pebbles near the wall forming ordered layers similar to hexagonal close packing. Next, variations in the local packing density are investigated by comparing probability density functions of the packing fraction of small clusters of pebbles throughout the bed. Especially near the wall large variations in local packing fractions exists, with a higher probability for both clusters of pebbles with low (<0.6) and high (>0.65) packing fraction, which could significantly affect flow rates and, together with higher power densities, could result in hotspots. (authors)

Auwerda, G. J.; Kloosterman, J. L.; Lathouwers, D.; Van Der Hagen, T. H. J. J. [Delft Univ. of Technology, Mekelweg 15, 2629 JB, Delft (Netherlands)

2012-07-01

192

New hydraulics laboratory  

NASA Astrophysics Data System (ADS)

The DeFrees Hydraulics Laboratory was opened in June 1984 as a 500-m2 addition to the former hydraulics teaching laboratory in Cornell University's School of Civil and Environmental Engineering. Total laboratory space is now about 800 m2 and is dedicated to basic and applied research and teaching in hydraulics, fluid mechanics, and hydrology. Three major equipment installations are in progress: a 33-m wave tank with a random wave generator for coastal/ocean engineering research, a 24-m wind-water tunnel for stratified flow and interfacial transfer research, and a 24-m tilting flume for open channel turbulence and sediment transport research.

193

Packing Schemes for Gang Scheduling  

Microsoft Academic Search

. Jobs that do not require all processors in the system can bepacked together for gang scheduling. We examine accounting traces fromseveral parallel computers to show that indeed many jobs have small sizesand can be packed together. We then formulate a number of such packingalgorithms, and evaluate their effectiveness using simulations based onour workload study. The results are that two

Dror G. Feitelson

1996-01-01

194

Wire and Packing Tape Sandwiches  

ERIC Educational Resources Information Center

In this article, the author describes how students can combine craft wire with clear packing tape to create a two-dimensional design that can be bent and twisted to create a three-dimensional form. Students sandwich wire designs between two layers of tape. (Contains 1 online resource.)

Rabinowitz, Sandy

2009-01-01

195

Disk packings and planar separators  

Microsoft Academic Search

We demonstrate that the geometric separator algorithm of Miller, Teng, Thurston, and Vavasis finds a 3\\/4-separator of size 1.84+ for every n node planar graph. Our bound is derived from an analysis of disk packings on the sphere,

Daniel A. Spielmant; Shang-Hua Teng

1996-01-01

196

Mystery Pellets ClassPack  

NSDL National Science Digital Library

Using Picture-Perfect Science Lessons 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 unmatched time-saver and a great deal. This Cla

2010-04-19

197

Mirror, Mirror ClassPack  

NSDL National Science Digital Library

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

2010-04-25

198

Imaginative Inventions ClassPack  

NSDL National Science Digital Library

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

2010-04-25

199

The Design & Planning Games Pack.  

ERIC Educational Resources Information Center

Over the next 10 months, five sections of a pack of environmental exercises will be presented (Houses Game, Planning Game, Building Designs, Planning Enquiry, Future Communities). This introduction (which includes instructions and materials for the Houses Game) suggests why such exercises are needed and describes problems they will help with.…

Bishop, Jeff; Russell, Graham

1982-01-01

200

Some thermal hydraulic challenges in sodium cooled fast reactors  

Microsoft Academic Search

Sodium cooled fast reactors have been developed in France for nearly 50 years with successively Rapsodie, Phenix and Superphenix plants. Thermal hydraulic challenges have progressively increased with the power and the size of the reactors. After Superphenix stop in 1997, the thermal hydraulic activity on sodium cooled fast reactors was drastically reduced for about 10 years. Nowadays, the so-called Astrid

D. Tenchine

2010-01-01

201

Hydraulic Pressure Intensifiers for Use by Working Divers.  

National Technical Information Service (NTIS)

The need for a reliable high pressure (10,000 psi) source of hydraulic power for use by divers has led to the evaluation and modification of two commercially available hydraulic pressure intensifiers, The operation of the internal mechanism of the intensi...

A. M. Parisi R. L. Brackett

1974-01-01

202

Applying Switched Reluctance Motor to Oil Hydraulic Pump Use  

NASA Astrophysics Data System (ADS)

Hydraulic pump units are widely used to operate hydraulic actuators. In a typical machine shop, conventional constant speed hydraulic pump units consume more than 20% of the total electric power necessary to operate CNC machine tools. Most of that energy are wasted to run the axial piston pump at idle. This paper describes a variable speed hydraulic pump unit using a switched reluctance motor (SRM), which saves energy drastically. SRM was selected as the most suitable motor for this application. Design and control strategy of this motor are described. Application examples to machine tools shows the effectiveness of the new hybrid pump system in saving energy and in reducing acoustic noise.

Yamai, Hiroyuki; Sawada, Yuzo; Ohyama, Kazunobu

203

Minimum Size and Maximum Packing Density of Nonredundant Semiconductor Devices  

Microsoft Academic Search

It is shown that there exists an absolute lower limit to device size and an absolute upper limit to packing density of nonredundant semiconductor devices, whether integrated or nonintegrated, based on fundamental physical phenomena such as statistical variations in impurity distribution, maximum resolution of semiconductor fabrication methods, power density and influence of cosmic rays. The influence of these phenomena falls

J. T. Wallmark; S. M. Marcus

1962-01-01

204

Hydraulic Hoisting and Backfilling.  

National Technical Information Service (NTIS)

In a country such as South Africa, with its large deep level mining industry, improvements in mining and hoisting techniques could result in substantial savings. Hoisting techniques, for example, may be improved by the introduction of hydraulic hoisting. ...

H. B. Sauermann

1982-01-01

205

Investigations of Hydraulic Turbines.  

National Technical Information Service (NTIS)

Contents: Effects of the initial degree of turbulence on the hydrodynamic coefficients of the blade systems of axial hydraulic turbines; Accuracy of determining the flow around straight blade cascades; Application of Stanitz and Prian's approximate theory...

G. A. Svinarev

1969-01-01

206

Aircraft Hydraulic Servomechanisms.  

National Technical Information Service (NTIS)

The authors have attempted to present to others concerned with the analysis, design, and testing of integrated aircraft control systems, certain fundamental information regarding the hydraulic servomechanisms used to position the aircraft control surfaces...

I. L. Ashkenas G. E. Click D. Graham J. W. Hager A. P. Henry

1969-01-01

207

Particle packing from an earth science viewpoint  

NASA Astrophysics Data System (ADS)

Particle packings are relevant to many aspects of the Earth sciences, and there is a long history of the study of packings from an Earth science viewpoint. Packings have also been studied in connection with other subjects and disciplines. Allen (1982) produced a major review which provides a solid base for Earth science related studies. This review complements Allen's work and in particular focuses on advances in the study of random packings over the last ten years. Transitions from packing to packing may be as important as the packings themselves, and possibly easier to model. This paper places emphasis on certain neglected works, in particular Morrow and Graves (1969) and the packing transition envelope, Kahn (1956) and the measurement of packing parameters, Griffiths (1962) on packings in one-dimension, and Getis and Boots (1978) on packings in two dimensions. Certain packing problems are relevant to current areas of study including structure collapse in loess (hydroconsolidation), flowslides in very sensitive soils, wind erosion, jewel quality in opals and the structure and functions of sand dunes. The region where interparticle forces become active (particles < 200 ?m) is considered and the implications for packing are examined.

Rogers, C. D. F.; Dijkstra, T. A.; Smalley, I. J.

1994-04-01

208

The crack tip region in hydraulic fracturing  

Microsoft Academic Search

We present analytical tip region solutions for fracture width and pressure when a power law fluid drives a plane strain fracture in an impermeable linear elastic solid. Our main result is an intermediate asymptotic solution in which the tip region stress is dominated by a singularity which is particular to the hydraulic fracturing problem. Moreover this singularity is weaker than

J. Desroches; E. Detournay; B. Lenoach; P. Papanastasiou; J. R. A. Pearson; M. Thiercelin; A. Cheng

1994-01-01

209

Empirical equations for some soil hydraulic properties  

Microsoft Academic Search

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.

Roger B. Clapp; George M. Hornberger

1978-01-01

210

Simulator for a packing and weighing system of granulated powders.  

PubMed

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

Couto Rodrigues de Oliveira, Rafael; Garcia, Claudio

2013-09-01

211

Water Vapor Permeability of Plastic Fast Packs.  

National Technical Information Service (NTIS)

The objective of this investigation was to perform nondestructive tests that quantitatively measured the water vapor permeability of a plastic (high density polyethylene) Type I Fast Pack design. The water vapor transmission rate (WVTR) of the new pack de...

J. A. Hincks

1978-01-01

212

Generation of Random Particle Packings for Discrete Element Models  

NASA Astrophysics Data System (ADS)

An important step in the setup process of Discrete Element Model (DEM) simulations is the generation of a suitable particle packing. There are quite a number of properties such a granular material specimen should ideally have, such as high coordination number, isotropy, the ability to fill arbitrary bounding volumes and the absence of locked-in stresses. An algorithm which is able to produce specimens fulfilling these requirements is the insertion based sphere packing algorithm originally proposed by Place and Mora, 2001 [2] and extended in this work. The algorithm works in two stages. First a number of "seed" spheres are inserted into the bounding volume. In the second stage the gaps between the "seed" spheres are filled by inserting new spheres in a way so they have D+1 (i.e. 3 in 2D, 4 in 3D) touching contacts with either other spheres or the boundaries of the enclosing volume. Here we present an implementation of the algorithm and a systematic statistical analysis of the generated sphere packings. The analysis of the particle radius distribution shows that they follow a power-law with an exponent ? D (i.e. ?3 for a 3D packing and ?2 for 2D). Although the algorithm intrinsically guarantees coordination numbers of at least 4 in 3D and 3 in 2D, the coordination numbers realized in the generated packings can be significantly higher, reaching beyond 50 if the range of particle radii is sufficiently large. Even for relatively small ranges of particle sizes (e.g. Rmin = 0.5Rmax) the maximum coordination number may exceed 10. The degree of isotropy of the generated sphere packing is also analysed in both 2D and 3D, by measuring the distribution of orientations of vectors joining the centres of adjacent particles. If the range of particle sizes is small, the packing algorithm yields moderate anisotropy approaching that expected for a face-centred cubic packing of equal-sized particles. However, once Rmin < 0.3Rmax a very high degree of isotropy is demonstrated in both 2D and 3D. The analysis demonstrates that this space-filling packing algorithm fulfills many of the requirements required to produce granular material specimens for DEM simulations. These include a high coordination number, isotropy and the absence of lock-in stresses. The algorithm has been implemented as a module (called gengeo[1]) for the Python[3] scripting language and provides the capacity to fill arbitrary bounding volumes or combinations of bounding volumes. The main disadvantage of this space-filling packing approach is the inability to specify a priori the particle size distribution of the final specimen.

Abe, S.; Weatherley, D.; Ayton, T.

2012-04-01

213

Nonlinear elastic stress response in granular packings  

NASA Astrophysics Data System (ADS)

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 [Phys. Rev. Lett. 87, 035506 (2001)] on isotropic and hexagonal packings of photoelastic grains can be fitted 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.

Tighe, Brian P.; Socolar, Joshua E. S.

2008-03-01

214

Cell aggregation: Packing soft grains  

NASA Astrophysics Data System (ADS)

Cellular aggregates may be considered as collections of membrane enclosed units with a pressure difference between the internal and external liquid phases. Cells are kept together by membrane adhesion and/or confined space compression. Pattern formation and, in particular, intercellular spacing have important roles in controlling solvent diffusion within such aggregates. A physical approach is used to study generic aspects of cellular packings in a confined space. Average material properties are derived from the free energy. The appearance of penetrating intercellular void channels is found to be critically governed by the cell wall adhesion mechanisms during the formation of dense aggregates. A fully relaxed aggregate efficiently hinders solvent diffusion at high hydrostatic pressures, while a small fraction (˜0.1) of adhesion related packing frustration is sufficient for breaking such a blockage even at high a pressure.

Åström, J. A.; Karttunen, M.

2006-06-01

215

Free-piston regenerative hot gas hydraulic engine  

NASA Technical Reports Server (NTRS)

A displacer piston which is driven pneumatically by a high-pressure or low-pressure gas is included in a free-piston regenerative hydraulic engine. Actuation of the displacer piston circulates the working fluid through a heater, a regenerator and a cooler. The present invention includes an inertial mass such as a piston or a hydraulic fluid column to effectively store and supply energy during portions of the cycle. Power is transmitted from the working fluid to a hydraulic fluid across a diaphragm or lightweight piston to achieve a hydraulic power out-put. The displacer piston of the present invention may be driven pneumatically, hydraulically or electromagnetically. In addition, the displacer piston and the inertial mass of the present invention may be positioned on the same side of the diaphragm member or may be separated by the diaphragm member.

Beremand, D. G. (inventor)

1980-01-01

216

Light Water Breeder Reactor movable fuel hydraulic balancing system (LWBR Development Program)  

Microsoft Academic Search

Reactivity control in the Light Water Breeder Reactor (LWBR) is obtained by axial positioning of twelve movable fuel assemblies, which thus serve the dual purpose of contributing to reactor power and functioning as neutron economic control elements. A hydraulic technique is used to automatically counterbalance the upward hydraulic force of these elements. Hydraulic balancing is accomplished using the Bypass Inlet

P. R. Bengel; J. R. Turner; S. W. Jr. Sinderson

1979-01-01

217

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

ERIC Educational Resources Information Center

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…

Human Engineering Inst., Cleveland, OH.

218

Characteristics of fluidized-packed beds  

NASA Technical Reports Server (NTRS)

Study of fluidized-packed bed includes investigation of heat transfer, solids-gas mixing, and elutriation characteristics. A fluidized-packed bed is a system involving the fluidization of small particles in the voids of a packed bed of larger nonfluidized particles.

Gabor, J. D.; Mecham, W. J.

1968-01-01

219

Two-dimensional packing problems: A survey  

Microsoft Academic Search

We consider problems requiring to allocate a set of rectangular items to larger rectangular standardized units by minimizing the waste. In two-dimensional bin packing problems these units are finite rectangles, and the objective is to pack all the items into the minimum number of units, while in two-dimensional strip packing problems there is a single standardized unit of given width,

Andrea Lodi; Silvano Martello; Michele Monaci

2002-01-01

220

A numerical case study of packed columns  

Microsoft Academic Search

This paper presents results concerning the validation of a recently developed packing algorithm. The basic ethos of this algorithm, known as DigiPac, is to use three-dimensional methods to digitise particle shapes, and to use this digital information directly in computations of how particles pack together without further conversion or the need for modelling. A variety of simulations of packed columns,

R. Caulkin; M. Fairweather; X. Jia; R. A. Williams

2005-01-01

221

DNA Organization and Thermodynamics during Viral Packing  

Microsoft Academic Search

An elastic DNA molecular mechanics model is used to compare DNA structures and packing thermodynamics in two bacteriophage systems, T7 and ?29. A discrete packing protocol allows for multiple molecular dynamics simulations of the entire packing event. In T7, the DNA is coaxially spooled around the cylindrical core protein, whereas the ?29 system, which lacks a core protein, organizes the

C. Rebecca Locker; Stephen D. Fuller; Stephen C. Harvey

2007-01-01

222

Planet packing in circumbinary systems  

NASA Astrophysics Data System (ADS)

The recent discovery of planets orbiting main-sequence binaries will provide crucial constraints for theories of binary and planet formation. The formation pathway for these planets is complicated by uncertainties in the formation mechanism of the host stars. In this paper, we compare the dynamical states of single- and binary-star planetary systems. Specifically, we pose two questions: (1) What does it mean for a circumbinary system to be dynamically packed? (2) How many systems are required to differentiate between a population of packed or sparse planets? We determine when circumbinary systems become dynamically unstable as a function of the separation between the host-stars and the inner planet, and the first and second planets. We show that these represent unique stability constraints compared to single-star systems. We find that although the existing Kepler data is insufficient to distinguish between a population of packed or sparse circumbinary systems, a more thorough study of circumbinary Transit Timing Variations (TTVs) combined with an order of magnitude increase in the number of systems may prove conclusive. Future space missions such as TESS provide the best opportunity for increasing the sample size.

Kratter, Kaitlin M.; Shannon, Andrew

2014-02-01

223

A packed-bed fungal bioreactor for the continuous decolourisation of azo-dyes (Orange II)  

Microsoft Academic Search

The degradation of an azo dye, Orange II, by immobilised Phanerochaete chrysosporium in a continuous packed bed bioreactor for periods longer than 30 days has been carried out. Nearly complete decolourisation (>95%) was achieved when working at a high dye load rate of 0.2 g l?1 d?1, a temperature of 37°C, a hydraulic retention time (HRT) of 24 h and

I Mielgo; M. T Moreira; G Feijoo; J. M Lema

2001-01-01

224

Frequency distribution of mechanically stable disk packings  

SciTech Connect

Relative frequencies of mechanically stable (MS) packings of frictionless bidisperse disks are studied numerically in small systems. The packings are created by successively compressing or decompressing a system of soft purely repulsive disks, followed by energy minimization, until only infinitesimal particle overlaps remain. For systems of up to 14 particles, most of the MS packings were generated. We find that the packings are not equally probable as has been assumed in recent thermodynamic descriptions of granular systems. Instead, the frequency distribution, averaged over each packing-fraction interval {delta}{phi}, grows exponentially with increasing {phi}. Moreover, within each packing-fraction interval, MS packings occur with frequencies f{sub k} that differ by many orders of magnitude. Also, key features of the frequency distribution do not change when we significantly alter the packing-generation algorithm; for example, frequent packings remain frequent and rare ones remain rare. These results indicate that the frequency distribution of MS packings is strongly influenced by geometrical properties of the multidimensional configuration space. By adding thermal fluctuations to a set of the MS packings, we were able to examine a number of local features of configuration space near each packing. We measured the time required for a given packing to break to a distinct one, which enabled us to estimate the energy barriers that separate one packing from another. We found a gross positive correlation between the packing frequencies and the heights of the lowest energy barriers {epsilon}{sub 0}; however, there is significant scatter in the data. We also examined displacement fluctuations away from the MS packings to assess the size and shape of the local basins near each packing. The displacement modes scale as d{sub i}{approx}{epsilon}{sub 0}{sup {gamma}{sub i}} with {gamma}{sub i} ranging from {approx}0.6 for the largest eigenvalues to 1.0 for the smallest ones. These scalings suggest that the packing frequencies are not determined by the local volume of configuration space near each packing, which would require that the dependence of f{sub k} on {epsilon}{sub 0} is much stronger than the dependence we observe. The scatter in our data implies that in addition to {epsilon}{sub 0} there are also other, as yet undetermined variables that influence the packing probabilities.

Gao Guojie; Blawzdziewicz, Jerzy [Department of Mechanical Engineering, Yale University, New Haven, Connecticut 06520-8284 (United States); O'Hern, Corey S. [Department of Mechanical Engineering, Yale University, New Haven, Connecticut 06520-8284 (United States); Department of Physics, Yale University, New Haven, Connecticut 06520-8120 (United States)

2006-12-15

225

Effects of packing rates of cubic-shaped polyurethane foam carriers on the microbial community and the removal of organics and nitrogen in moving bed biofilm reactors.  

PubMed

The effects of packing rates (20%, 30%, and 40%) of polyurethane foam (PUF) to the removal of organics and nitrogen were investigated by continuously feeding artificial sewage in three aerobic moving bed biofilm reactors. The results indicated that the packing rate of the PUF carriers had little influence on the COD removal efficiency (81% on average). However, ammonium removal was affected by the packing rates, which was presumably due to the different relative abundances of nitrifying bacteria. A high ammonium removal efficiency of 96.3% at a hydraulic retention time of 5h was achieved in 40% packing rate reactor, compared with 37.4% in 20% packing rate. Microprofiles of dissolved oxygen and nitrate revealed that dense biofilm limits the DO transfer distance and nitrate diffusion. Pyrosequencing analysis of the biofilm showed that Proteobacteria, Bacteroidetes and Verrucomicrobia were the three most abundant phyla, but the proportions of the microbial community varied with the packing rate of the PUF carriers. PMID:22621807

Feng, Quan; Wang, Yuxiao; Wang, Tianmin; Zheng, Hao; Chu, Libing; Zhang, Chong; Chen, Hongzhang; Kong, Xiuqin; Xing, Xin-Hui

2012-08-01

226

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.

227

Kinetics of pack aluminization of nickel  

NASA Technical Reports Server (NTRS)

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.

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

1978-01-01

228

What Is Hydraulic Fracturing?  

NSDL National Science Digital Library

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.

2012-01-01

229

Simple description of flow instability with application to a packed bed.  

National Technical Information Service (NTIS)

A simplified explanation for gas flow instability in parallel heated channels is presented with specific applications to channels containing packed beds of power-producing particles. The explanation captures the basic governing physics of the viscosity-dr...

D. Dobranich

1993-01-01

230

Performance estimation of dust wipers for hydraulic cylinders and optimization of geometric design variables  

Microsoft Academic Search

Hydraulic cylinders are widely used as actuators for construction machines, airplanes and military machines. In the case of these devices, due to their use under severe environmental conditions, such as excessive water, SiO2 and dust seals which has a high packing ability and long service life have normally been required. These characteristics are largely influenced by the material and geometries

K. O. Lee; Y. M. Hur; J. H. Kang; S. S. Kang

2007-01-01

231

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.

2008-02-07

232

Coarse coal hydraulic transport  

Microsoft Academic Search

Consolidation Coal Co's work on hydraulic transport in underground mining is recommended. After initial testing of the transport of coarse coal in a surface test plant, a pilot system was installed at Robinson Run Mine in West Virginia to investigate transport from a continuous miner to the surface of the drift and thence to the preparation plant. A pipe-wear pilot

Petry

1982-01-01

233

Downhole hydraulic actuated pump  

Microsoft Academic Search

This patent describes a downhole hydraulically actuated pump assembly of the type having a main housing within which an engine and pump is enclosed; a connecting rod, an engine piston, a pump plunger, means by which the engine and connecting rod reciprocate the pump plunger and thereby produces fluid; the main housing has a lower end having a formation fluid

Roeder

1988-01-01

234

Hydraulic Network Simulation.  

National Technical Information Service (NTIS)

The report summarizes the work done simulating a water radiator heating system as a whole coupled with the building using design data as input and using measured data for verification of the predictions. The exercise had three stages: hydraulic balance, t...

R. Kohonen A. Laitinen M. Virtanen

1989-01-01

235

Hydraulic Structures for Wetlands.  

National Technical Information Service (NTIS)

This technical note examines hydraulic structures presently being used in wetland design. The examples given will provide insight to structure types being used in the field and how well they are succeeding. The design and construction of a wetland site re...

1993-01-01

236

Hydraulic Impulse Speargun.  

National Technical Information Service (NTIS)

A hydraulic speargun has an elongated elastomeric bladder for charging the gun. One end of the bladder selectively communicates with the breech chamber at the end of the gun barrel. The other end of the bladder is connected to a pump for inflating the bla...

L. Bissonnette

1996-01-01

237

Hydraulic borehole mining system  

Microsoft Academic Search

A hydraulic underground mining system is disclosed for operating through a small diameter borehole into a subterranean body. An elongated mining tool includes a liquid jet nozzle that is movable in vertical direction along the length of the mining tool for forming a directed jet stream to impact material in the ore body and convert the material into a slurry.

1983-01-01

238

Water Treatment Technology - Hydraulics.  

ERIC Educational Resources Information Center

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…

Ross-Harrington, Melinda; Kincaid, G. David

239

Integration in Hydraulics.  

ERIC Educational Resources Information Center

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…

Sworder, Steven C.

240

Hydraulic Shutdown Monitor  

NASA Technical Reports Server (NTRS)

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.

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

1986-01-01

241

Digital Hydraulic Actuator Study.  

National Technical Information Service (NTIS)

The progress is reported on the Digital Hydraulic Actuator (DHA) Study as related to a Polaris application. The purpose of the DHA Phase I Study is to establish and define the pertinent parameters which impact control system performance with Polaris as a ...

1964-01-01

242

Hydraulic Pressure Intensifier.  

National Technical Information Service (NTIS)

A hydraulic pressure intensifier is used to raise the pressure in an accumulator above a given input pressure. An oscillating piston provides a boost pressure while a pilot valve and a dump valve and restrictors allow the oscillating piston to move. (Auth...

R. S. Andrews

1985-01-01

243

Statistical mechanics of jammed packings of spheres  

NASA Astrophysics Data System (ADS)

The problem of finding the most efficient way to pack spheres has an illustrious history, dating back to the crystalline arrays conjectured by Kepler and the random geometries explored by Bernal in the 60's. There are presently numerous experiments showing that randomly packing spheres of equal size into a container consistently results in a static configuration with a density of 0.64. The ubiquity of random close packing (RCP) rather than the equilibrium crystalline array at 0.74 begs a new statistical framework. Here we introduce a general volume ensemble statistical approach for jammed packings of spheres. This approach provides a thermodynamic definition of RCP: RCP can be interpreted as a manifestation of a thermodynamic singularity, which defines it as the "freezing point'' in a first-order phase transition between ordered and disordered packing phases. We generalize the theory to jammed packings of high dimensional and different size spheres. The asymptotic high-dimensional scaling of the RCP density is consistent with that of other approaches, such as replica theory and density functional theory. The theory predicts the density of random close packing and random loose packing (RLP) of polydisperse systems for a given distribution of sphere size. The present mean-field approach may help to treat packing problems of non-spherical particles, and could serve as a starting point to understand the higher-order correlations present in jammed packings.

Jin, Yuliang

244

Cradle modification for hydraulic ram  

SciTech Connect

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}).

Koons, B.M.

1995-03-02

245

Flexibility and packing in proteins  

NASA Astrophysics Data System (ADS)

Structural flexibility is an essential attribute, without which few proteins could carry out their biological functions. Much information about protein flexibility has come from x-ray crystallography, in the form of atomic mean-square displacements (AMSDs) or B factors. Profiles showing the AMSD variation along the polypeptide chain are usually interpreted in dynamical terms but are ultimately governed by the local features of a highly complex energy landscape. Here, we bypass this complexity by showing that the AMSD profile is essentially determined by spatial variations in local packing density. On the basis of elementary statistical mechanics and generic features of atomic distributions in proteins, we predict a direct inverse proportionality between the AMSD and the contact density, i.e., the number of noncovalent neighbor atoms within a local region of ~1.5 nm3 volume. Testing this local density model against a set of high-quality crystal structures of 38 nonhomologous proteins, we find that it accurately and consistently reproduces the prominent peaks in the AMSD profile and even captures minor features, such as the periodic AMSD variation within helices. The predicted rigidifying effect of crystal contacts also agrees with experimental data. With regard to accuracy and computational efficiency, the model is clearly superior to its predecessors. The quantitative link between flexibility and packing density found here implies that AMSDs provide little independent information beyond that contained in the mean atomic coordinates.

Halle, Bertil

2002-02-01

246

Hydraulic Drives of Aircraft. Part I.  

National Technical Information Service (NTIS)

Contents: The place occupied by hydraulic systems in equipment of aircraft; Working fluids and their properties; Basic information on hydraulics of pipelines; Pumps and hydraulic motors; Pumps and hydraulic motors of piston types; Axial-piston pumps and h...

T. M. Bashta

1969-01-01

247

Determining the Porosity and Saturated Hydraulic Conductivity of Binary Mixtures  

SciTech Connect

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.

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

2011-02-14

248

Determining the Porosity and Saturated Hydraulic Conductivity of Binary Mixtures  

SciTech Connect

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.

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

2009-09-27

249

Computer simulation of hydraulic fractures  

Microsoft Academic Search

We provide a brief historical background of the development of hydraulic fracturing models for use in the petroleum and other industries. We discuss scaling laws and the propagation regimes that control the growth of hydraulic fractures from the laboratory to the field scale. We introduce the mathematical equations and boundary conditions that govern the hydraulic fracturing process, and discuss numerical

J. Adachi; E. Siebrits; A. Peirce; J. Desroches

2007-01-01

250

Electrokinetic high pressure hydraulic system  

Microsoft Academic Search

A compact high pressure hydraulic pump having no moving mechanical parts for converting electric potential to hydraulic force is described. The electrokinetic pump, which can generate hydraulic pressures greater than 2,500 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

P. H. Paul; D. J. Rakestraw

2000-01-01

251

Electrokinetic high pressure hydraulic system  

Microsoft Academic Search

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

Phillip H. Paul; David J. Rakestraw

2000-01-01

252

Iterative packing for demand matching and sparse packing.  

SciTech Connect

The main result we will present is a 2k-approximation algorithm for the following 'k-hypergraph demand matching' problem: given a set system with sets of size <=k, where sets have profits & demands and vertices have capacities, find a max-profit subsystem whose demands do not exceed the capacities. The main tool is an iterative way to explicitly build a decomposition of the fractional optimum as 2k times a convex combination of integral solutions. If time permits we'll also show how the approach can be extended to a 3-approximation for 2-column sparse packing. The second result is tight w.r.t the integrality gap, and the first is near-tight as a gap lower bound of 2(k-1+1/k) is known.

Parekh, Ojas

2010-11-01

253

The Packing of Granular Polymer Chains  

SciTech Connect

Rigid particles pack into structures, such as sand dunes on the beach, whose overall stability is determined by the average number of contacts between particles. However, when packing spatially extended objects with flexible shapes, additional concepts must be invoked to understand the stability of the resulting structure. Here, we examine the disordered packing of chains constructed out of flexibly connected hard spheres. Using x-ray tomography, we find that long chains pack into a low-density structure whose mechanical rigidity is mainly provided by the backbone. On compaction, randomly oriented, semi-rigid loops form along the chain, and the packing of chains can be understood as the jamming of these elements. Finally, we uncover close similarities between the packing of chains and the glass transition in polymers.

Zou, Ling-Nan; Cheng, Xiang; Rivers, Mark L.; Jaeger, Heinrich M.; Nagel, Sidney R.; UC

2009-12-01

254

Theory of cylindrical dense packings of disks  

NASA Astrophysics Data System (ADS)

We have previously explored cylindrical packings of disks and their relation to sphere packings. Here we extend the analytical treatment of disk packings, analyzing the rules for phyllotactic indices of related structures and the variation of the density for line-slip structures, close to the symmetric ones. We show that rhombic structures, which are of a lower density, are always unstable, i.e., can be increased in density by small perturbations.

Mughal, A.; Weaire, D.

2014-04-01

255

Preservation, Packaging and Packing for Space Systems.  

National Technical Information Service (NTIS)

The document establishes the general requirements for preparation for delivery including cleaning, preservation, packaging, packing, and marking for shipment and storage of deliverable material items for space systems.

1966-01-01

256

Random close packing of polydisperse jammed emulsions  

NASA Astrophysics Data System (ADS)

Packing problems are everywhere, ranging from oil extraction through porous rocks to grain storage in silos and the compaction of pharmaceutical powders into tablets. At a given density, particulate systems pack into a mechanically stable and amorphous jammed state. Theoretical frameworks have proposed a connection between this jammed state and the glass transition, a thermodynamics of jamming, as well as geometric modeling of random packings. Nevertheless, a simple underlying mechanism for the random assembly of athermal particles, analogous to crystalline ordering, remains unknown. Here we use 3D measurements of polydisperse packings of emulsion droplets to build a simple statistical model in which the complexity of the global packing is distilled into a local stochastic process. From the perspective of a single particle the packing problem is reduced to the random formation of nearest neighbors, followed by a choice of contacts among them. The two key parameters in the model, the available space around a particle and the ratio of contacts to neighbors, are directly obtained from experiments. Remarkably, we demonstrate that this ``granocentric'' view captures the properties of the polydisperse emulsion packing, ranging from the microscopic distributions of nearest neighbors and contacts to local density fluctuations and all the way to the global packing density. Further applications to monodisperse and bidisperse systems quantitatively agree with previously measured trends in global density. This model therefore reveals a general principle of organization for random packing and lays the foundations for a theory of jammed matter.

Brujic, Jasna

2010-03-01

257

Numerical simulation of a shear-thinning fluid through packed spheres  

NASA Astrophysics Data System (ADS)

Flow behaviors of a non-Newtonian fluid in spherical microstructures have been studied by a direct numerical simulation. A shear-thinning (power-law) fluid through both regular and randomly packed spheres has been numerically investigated in a representative unit cell with the tri-periodic boundary condition, employing a rigorous three-dimensional finite-element scheme combined with fictitious-domain mortar-element methods. The present scheme has been validated for the classical spherical packing problems with literatures. The flow mobility of regular packing structures, including simple cubic (SC), body-centered cubic (BCC), face-centered cubic (FCC), as well as randomly packed spheres, has been investigated quantitatively by considering the amount of shear-thinning, the pressure gradient and the porosity as parameters. Furthermore, the mechanism leading to the main flow path in a highly shear-thinning fluid through randomly packed spheres has been discussed.

Liu, Hai Long; Moon, Jong Sin; Hwang, Wook Ryol

2012-12-01

258

The application of hydraulics in the 2,000 kW wind turbine generator  

Microsoft Academic Search

A 2000 kW turbine generator using hydraulic power in two of its control systems is being built under the management of NASA Lewis Research Center. The hydraulic systems providing the control torques and forces for the yaw and blade pitch control systems are discussed. The yaw-drive-system hydraulic supply provides the power for positioning the nacelle so that the rotary axis

S. Onufreiczuk

1978-01-01

259

Chain packing in polycarbonate glasses  

NASA Astrophysics Data System (ADS)

Chain packing in homogeneous blends of carbonate 13C-labeled bisphenol A polycarbonate with either (i) CF3-labeled bisphenol A polycarbonate or (ii) ring-F-labeled bisphenol A polycarbonate has been characterized using 13C{19F} rotational-echo double-resonance (REDOR) nuclear magnetic resonance. In both blends, the 13C observed spin was at high concentration, and the 19F dephasing or probe spin was at low concentration. In this situation, an analysis in terms of a distribution of isolated heteronuclear pairs of spins is valid. Nearest-neighbor separation of 13C and 19F labels was determined by accurately mapping the initial dipolar evolution using a shifted-pulse version of REDOR. Based on the results of this experiment, the average distance from a ring-fluorine to the nearest 13C=O is more than 1.2 A? greater than the corresponding CF3-13C=O distance. Next-nearest and more-distant-neighbor separations of labels were measured in a 416-rotor-cycle constant-time version of REDOR for both blends. Statistically significant local order was established for the nearest-neighbor labels in the methyl-labeled blend. These interchain packing results are in qualitative agreement with predictions based on coarse-grained simulations of a specially adapted model for bisphenol A polycarbonate. The model itself has been previously used to determine static and dynamic properties of polycarbonate with results in good agreement with those from rheological and neutron scattering experiments.

Stueber, Dirk; Yu, Tsyr-Yan; Hess, Berk; Kremer, Kurt; O'Connor, Robert D.; Schaefer, Jacob

2010-03-01

260

Mathematical modeling of high-rate Anammox UASB reactor based on granular packing patterns.  

PubMed

A novel mathematical model was developed to estimate the volumetric nitrogen conversion rates of a high-rate Anammox UASB reactor based on the packing patterns of granular sludge. A series of relationships among granular packing density, sludge concentration, hydraulic retention time and volumetric conversion rate were constructed to correlate Anammox reactor performance with granular packing patterns. It was suggested that the Anammox granules packed as the equivalent simple cubic pattern in high-rate UASB reactor with packing density of 50-55%, which not only accommodated a high concentration of sludge inside the reactor, but also provided large pore volume, thus prolonging the actual substrate conversion time. Results also indicated that it was necessary to improve Anammox reactor performance by enhancing substrate loading when sludge concentration was higher than 37.8 gVSS/L. The established model was carefully calibrated and verified, and it well simulated the performance of granule-based high-rate Anammox UASB reactor. PMID:23434474

Tang, Chong-Jian; He, Rui; Zheng, Ping; Chai, Li-Yuan; Min, Xiao-Bo

2013-04-15

261

Remotely Adjustable Hydraulic Pump  

NASA Technical Reports Server (NTRS)

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.

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

1987-01-01

262

Liquid distribution studies in packed beds  

Microsoft Academic Search

Recent research has shown that liquid distribution is even more important to the apparent efficiency of packed columns than was previously believed. An ''Adjustable Liquid Distributor'' which allows distribution to be changed with the column in operation has been designed and is being used to gain more insight into packed column operation. Preliminary conclusions are that discontinuities and zonal flows

J. G. Kunesh; L. L. Lahm; T. Yanagi

1985-01-01

263

Multipoint, packed wire, and monolithic armatures  

Microsoft Academic Search

There are three types of nonarcing solid armatures that have been experimented with in railguns: multipoint armatures in which the faces of the armatures in sliding electrical contact with the rails consist of many more or less independent contact points or small patches; packed wire armatures in which the contact faces consist of very many packed wire ends; and monolithic

R. A. Marshall

1995-01-01

264

The Leader Pack: Outdoor Travel Insurance.  

ERIC Educational Resources Information Center

Provides outdoor leaders with suggestions for items to include in a leader pack. The pack should include a first aid kit, as well as survival and emergency gear. Recommends using a journal to document information about participants, events, and accidents. (KS)

Kozolanka, Karne

1992-01-01

265

Heat transfer in high temperature packed beds  

Microsoft Academic Search

A packed bed is modeled as a homogeneous gray medium in which heat is transferred by conduction, convection, and radiation. The problem is formulated wherein the packed bed is contained between concentric gray cylinders that are axially isothermal. The outer cylinder is at a high temperature, and heat transfer is radial through the bed to the low temperature inner cylinder.

1984-01-01

266

Rectangle-packing-based module placement  

Microsoft Academic Search

The first and the most critical stage in VLSI layout design is the placement, the background of which is the rectangle packing problem: Given many rectangular modules of arbitrary size, place them without overlapping on a layer in the smallest bounding rectangle. Since the variety of the packing is infinite (two- dimensionally continuous) many, the key issue for successful optimization

Hiroshi Murata; Kunihiro Fujiyoshi; Shigetoshi Nakatake; Yoji Kajitani

1995-01-01

267

A typology of cutting and packing problems  

Microsoft Academic Search

Cutting and packing problems appear under various names in literature, e.g. cutting stock or trim loss problem, bin or strip packing problem, vehicle, pallet or container loading problem, nesting problem, knapsack problem etc. The paper develops a consistent and systematic approach for a comprehensive typology integrating the various kinds of problems. The typology is founded on the basic logical structure

Harald Dyckhoff

1990-01-01

268

Pack Density Limitations of Hybrid Parachutes  

NASA Technical Reports Server (NTRS)

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.

Zwicker, Matthew L.; Sinclair, Robert J.

2013-01-01

269

Probe with integrated heater and thermocouple pack  

SciTech Connect

This patent describes a gamma thermometer probe for detecting heat produced within the thermometer probe. It comprises: an outer elongate thermometer sheath; an elongate rod; annular recesses; a longitudinal bore; and an integrated thermocouple pack. The thermocouple pack comprises: a first type wire, and second type wires. The second type wires comprises: an outer section; and an inner segment.

McCulloch, R.W.; Dial, R.E.; Finnell, W.F.R.

1988-02-16

270

NEW TEACHER WELCOME PACK: ELEMENTARY SCHOOL  

NSDL National Science Digital Library

Assortment of "Best-Selling" books for Elementary School Teachers. Pack includes the following books. Picture Perfect Science, Exemplary Science Grades K-4, Uncovering Student Ideas in Science, Volume 1, Using Science Notebooks, and Everyday Science Mysteries. Books are packed into a waterproof, nylon briefcase with handle and shoulder strap. Front flap of briefcase is printed with the NSTA logo.

1900-01-01

271

Record high Wolf, Canis lupus, pack density  

USGS Publications Warehouse

This report documents a year-around Wolf (Canis lupus) density of 18.2/100 km2 and a summer density of 30.8/100 km2, in a northeastern Minnesota Wolf pack. The previous record was a summer density of 14.1/100 km2, for a Wolf pack on Vancouver Island, British Columbia, Canada.

Mech, L. D.; Tracy, S.

2004-01-01

272

Record high wolf, Canis lupus, pack density  

USGS Publications Warehouse

This report documents a year-around wolf (Canis lupus) density of 18.2/100 m2 and summer density of 30.8/100 km2, in a northeastern Minnesota wolf pack. The previous record was a summer density of 14.1/100 km2, for a wolf pack on Vancouver Island, BC, Canada.

Mech, L. D.; Tracy, S.

2004-01-01

273

Orientational order in random packings of ellipses  

NASA Astrophysics Data System (ADS)

By means of Monte Carlo simulations, we examine the behavior of random packings of hard ellipses formed by pouring into a two-dimensional container. The particles pack so that their semimajor axes are preferentially aligned with the horizontal, and their orientational alignment increases with increasing aspect ratio. This self-organizational effect is accompanied by a corresponding reduction in the translational order of the centers of masses of the particles. For sufficiently elongated particles no translational order is present: The packings are amorphous, but still exhibit long-range orientational order. We call this state a ``nematic glass.'' We find that the orientational order also increases as the rate of deposition is reduced. The orientational order decreases if the packings are shaken. The behavior of the packings can be explained heuristically as being the result of competition between two local-potential-energy-minimization processes. The relevance of our results to materials science and petroleum engineering is discussed.

Buchalter, B. J.; Bradley, R. Mark

1992-09-01

274

Consolidated proppant pack for producing formations  

SciTech Connect

This patent describes a method for forming a porous, consolidated proppant pack at or in a producing formation in an earthen well. The method comprising: mixing both proppants which have been coated with an unset consolidating material and particles of a dissolvable material into a carrier liquid; flowing the carrier fluid with the proppants and the particles entrained therein down the well to the formation; allowing the proppants and the particles to remain at rest until the consolidating material on the proppants sets and consolidates to form the porous consolidated proppant pack; and dissolving the particles of the dissolvable material after the proppant pack has been consolidated to thereby increase the porosity and hence, the permeability of the pack. Also described is a similar method to form a porous, consolidated proppant pack in an earthen well.

Manna, M.L.

1989-10-24

275

Microbial community analysis in biocathode microbial fuel cells packed with different materials  

PubMed Central

Biocathode MFCs using microorganisms as catalysts have important advantages in lowering cost and improving sustainability. Electrode materials and microbial synergy determines biocathode MFCs performance. In this study, four materials, granular activated carbon (GAC), granular semicoke (GS), granular graphite (GG) and carbon felt cube (CFC) were used as packed cathodic materials. The microbial composition on each material and its correlation with the electricity generation performance of MFCs were investigated. Results showed that different biocathode materials had an important effect on the type of microbial species in biocathode MFCs. The microbes belonging to Bacteroidetes and Proteobacteria were the dominant phyla in the four materials packed biocathode MFCs. Comamonas of Betaproteobacteria might play significant roles in electron transfer process of GAC, GS and CFC packed biocathode MFCs, while in GG packed MFC Acidovorax may be correlated with power generation. The biocathode materials also had influence on the microbial diversity and evenness, but the differences in them were not positively related to the power production.

2012-01-01

276

Grain packing resistance to particle mobility  

NASA Astrophysics Data System (ADS)

We report the first measurements of grain packing resistance to particle motion. Packing resistance was resolved 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). Because paired measurements were not available, Monte Carlo simulations were conducted to develop distributions of packing resistance from observed distributions of total and pocket angle resistance. Expressed as coefficients of friction, grain packing increased with decreasing grain size and was close to 18 times higher for smaller grains (22.6 for the 5.7 mm size class) than larger grains (1.5 for the 22.6 mm size class) because small grains tend to be more embedded, which increases the extent of packing by surrounding grains. Grain weight is included in the packing resistance force, which increased with grain size from 5 grams-force to over 98 grams-force, and was the dominant form of resistance to grain motion, exceeding pocket angle resistance by up to 88%. Percentiles of packing forces and packing coefficients of friction diverge from common origins as a function of relative grain size (Di/D50). Packing force percentiles can be expressed as a function of grain size, embeddedness, and the standard deviation of grain sizes on the bed surface (sorting), which collectively control the friction surface area of the grain. Including packing in calculations of critical bed shear stress increased thresholds of grain motion by 8 to 46% (21% average) over that calculated with pocket angles of resistance alone. 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.

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

2013-12-01

277

Hydraulic mining method  

DOEpatents

A method of hydraulically mining an underground pitched mineral vein comprising drilling a vertical borehole through the earth's lithosphere into the vein and drilling a slant borehole along the footwall of the vein to intersect the vertical borehole. Material is removed from the mineral vein by directing a high pressure water jet thereagainst. The resulting slurry of mineral fragments and water flows along the slant borehole into the lower end of the vertical borehole from where it is pumped upwardly through the vertical borehole to the surface.

Huffman, Lester H. (Kent, WA); Knoke, Gerald S. (Kent, WA)

1985-08-20

278

Modular hydraulic control system  

NASA Astrophysics Data System (ADS)

A system of modular electrohydraulic servovalves is centrally controlled and may be used to control the operation of critical hydraulic actuators. A programmable controller operates a group of modular servovalves which each deliver a portion of the total actuator fluid requirements. The flow rate, valve position, and valve pressure of each servovalve is monitored by the controller and compared to expected values in memory to determine whether a servovalve malfunction exists. If so, the controller maintains the required flow rate to the actuator by closing the malfunctioning valve and either activating a spare or proportionally increasing the flow rates of the remaining servovalves to compensate for the loss.

Winyard, David C.; Lindstrom, Waldemar C.

1994-06-01

279

Operation of Packed-Bed Reactors Studied in Microgravity  

NASA Technical Reports Server (NTRS)

The operation of a packed bed reactor (PBR) involves gas and liquid flowing simultaneously through a fixed-bed of solid particles. Depending on the application, the particles can be various shapes and sizes but are generally designed to force the two fluid phases through a tortuous route of narrow channels connecting the interstitial space. The PBR is the most common type of reactor in industry because it provides for intimate contact and high rates of transport between the phases needed to sustain chemical or biological reactions. The packing may also serve as either a catalyst or as a support for growing biological material. Furthermore, this type of reactor is relatively compact and requires minimal power to operate. This makes it an excellent candidate for unit operations in support of long-duration human space activities.

Motil, Brian J.; Balakotaiah, Vemuri

2004-01-01

280

Proceedings of the fifth nuclear thermal hydraulics  

SciTech Connect

This book contains the fifth proceedings of Nuclear Thermal Hydraulics. Topics covered include: General Thermal-Hydraulics Modeling and Experiments; Thermal-Hydraulics Aspects of Passive Safety and New Generation Reactors; Thermal Hydraulics of Severe Accidents and Degraded Cores; General Thermal-Hydraulics Modeling and Experiments; Scaling and Uncertainties in Computer Code Predictions; Thermal Hydraulics of Reactor Operations; Thermal-Hydraulic Aspects of Passive Safety and New Generation Reactors; Thermal-Hydraulic Reactor Systems; and Thermal-Hydraulic Aspects of Passive Safety and New Generation Reactors.

Not Available

1989-01-01

281

Hydraulic Pumps and Hydraulic Equipment at Low Temperatures.  

National Technical Information Service (NTIS)

The ambient temperature may be -40 - -60 deg C in arctic conditions. This causes hardening and shrinkage of seals, deterioration of the suction ability of hydraulic pumps, brittleness in metals and more viscous hydraulic fluids. This may result in oil lea...

R. Soudunsaari A. Lehto

1987-01-01

282

Dual hydraulic safety valve  

SciTech Connect

This patent describes a subsurface well safety valve for controlling the fluid flow through a well conduit and including a housing having a bore and a valve closure member moving between open and closed positions for controlling the fluid flow through the bore, a tubular member telescopically moving in the housing for controlling the movement of the valve closure member. The improvement in fluid actuating means for actuating the valve closure member comprising, a first piston and cylinder assembly in the housing adapted to be connected to a hydraulic control line, the first assembly connected to the tubular member, a second piston and cylinder assembly in the housing adapted to be connected to a hydraulic control line, the second assembly disconnected from the tubular member, and means for disconnecting the first assembly from the tubular member and connecting the second assembly to the tubular member. The method of operating a subsurface well safety valve for controlling the fluid flow through a well conduit in which the valve includes a housing having a bore and a valve closure member moving between open and closed positions for controlling the fluid flow through the bore.

Leismer, D.D.; Blizzard, W.A. Jr.

1989-06-13

283

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

Code of Federal Regulations, 2013 CFR

...Alternate preservation, packaging, and packing. 211.272 Section 211.272 Federal...Alternate preservation, packaging, and packing. Use the provision at 252.211-7004, Alternate Preservation, Packaging, and Packing, in solicitations which include...

2013-10-01

284

75 FR 31283 - Clarification of Parachute Packing Authorization  

Federal Register 2010, 2011, 2012, 2013

...2120-AJ08 Clarification of Parachute Packing Authorization AGENCY: Federal Aviation...parachute rigger) was expressly limited to packing a main parachute of a dual-parachute...next jumper'' situations, parachute packing must be accomplished by or overseen...

2010-06-03

285

48 CFR 552.211-75 - Preservation, Packaging and Packing.  

Code of Federal Regulations, 2013 CFR

... false Preservation, Packaging and Packing. 552.211-75 Section 552.211-75...211-75 Preservation, Packaging and Packing. As prescribed in 511.204(b...clause: Preservation, Packaging, and Packing (FEB 1996) Unless otherwise...

2013-10-01

286

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

Code of Federal Regulations, 2010 CFR

...2010-10-01 false Alternate preservation, packaging, and packing. 211... 211.272 Alternate preservation, packaging, and packing. Use...211-7004, Alternate Preservation, Packaging, and Packing, in...

2010-10-01

287

48 CFR 552.211-75 - Preservation, Packaging and Packing.  

Code of Federal Regulations, 2010 CFR

...2010-10-01 false Preservation, Packaging and Packing. 552.211-75...Clauses 552.211-75 Preservation, Packaging and Packing. As prescribed...the following clause: Preservation, Packaging, and Packing (FEB...

2010-10-01

288

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

Code of Federal Regulations, 2010 CFR

...2009-10-01 false Alternate preservation, packaging, and packing. 211... 211.272 Alternate preservation, packaging, and packing. Use...211-7004, Alternate Preservation, Packaging, and Packing, in...

2009-10-01

289

48 CFR 552.211-75 - Preservation, Packaging and Packing.  

Code of Federal Regulations, 2010 CFR

...2009-10-01 false Preservation, Packaging and Packing. 552.211-75...Clauses 552.211-75 Preservation, Packaging and Packing. As prescribed...the following clause: Preservation, Packaging, and Packing (FEB...

2009-10-01

290

Flooding Characteristics of Packed Columns with High Efficiency.  

National Technical Information Service (NTIS)

Flooding characteristics of four high efficiency column packings, including Scientific Development Co. (SDC) protruded stainless distillation packing, Norton stainless pall rings, Podbielniak bronze Helipak, and Goodloe stainless wire mesh packing were de...

W. M. Choi R. C. Michel J. L. P. Varlet

1976-01-01

291

Packing, tiling, and covering with tetrahedra  

PubMed Central

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 be able to pack as densely as the sphere, which would contradict a conjecture of Ulam. The regular tetrahedron might even be the convex body having the smallest possible packing density.

Conway, J. H.; Torquato, S.

2006-01-01

292

DEM simulation of experimental dense granular packing  

SciTech Connect

In this study we present numerical analysis performed on the experimental results of sphere packings of mono-sized hard sphere whose packing fraction spans across a wide range of 0.59<{Phi}<0.72. Using X-ray Computed Tomography (XCT), we have full access to the 3D structure of the granular packings. Numerical analysis performed on thr data provides the first experimental proofs of how densification affects local order parameters. Furthermore by combining Discrete Element Method (DEM) and the experimental results from XCT, we investigate how the intergranular forces change with the onset of crystallization.

Hanifpour, Maryam; Allaei, Mehdi Vaez [Department of Physics, University of Tehran, Tehran (Iran, Islamic Republic of); Francois, Nicolas; Saadatfar, Mohammad [Department of Applied Mathematics, Research School of Physics and Engineering, Australian National University, Canberra (Australia)

2013-06-18

293

Leadership in wolf, Canis lupus, packs  

USGS Publications Warehouse

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.

Mech, L. D.

2000-01-01

294

Computer aided design in high pressure hydraulic systems  

SciTech Connect

There is a high demand made on the quality and efficiency of hydraulic systems. Increasing value is set on the knowledge of the dynamic behaviour of individual elements as well as on the layout of controlled systems. The use of the computer as an aid in the design, development and manufacture of components and systems is becoming increasingly common. Computer aided design has revolutionised industry. This book is a collection of case studies and research reports which make a valuable and practical contribution to the literature. Topics considered include benefit derived from Computer Aided Design in mining machinery; experience in using Computer Aided Design and draughting equipment in the mining manufacturing industry; CAD for the port plate of a two-bearing axial piston pump or motor; computer predictions of cyclic excitation sources for an external gear pump; component design by DSH programme; end plate balance in gear pumps; the design of self-centring seal-less hydraulic pistons; experience with computers in a hydraulics company; digital computer simulation as an aid to improving the performance of positive displacement pumps with self-acting valves; the development of an automatic procedure for the digital simulation of hydraulic systems; a micro-computer based aids for hydraulic system designers; computer aided design of split power hydrostatic transmission systems; desk top computer performance prediction package; program package HYKON for planning and design of hydraulic control blocks; and the solid modelling of fluid power components.

Not Available

1984-01-01

295

Tractor Hydraulics. A Teaching Reference.  

ERIC Educational Resources Information Center

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)…

American Association for Vocational Instructional Materials, Athens, GA.

296

Toxicological Profile for Hydraulic Fluids.  

National Technical Information Service (NTIS)

Hydraulic fluids have been found in at least 10 of the 1,428 current or former NPL sites. Hydraulic fluids are a very large class of materials that are used in machines and equipment to transfer pressure from one point to another. This profile covers only...

J. J. Corcoran M. O. Harris P. McClure R. L. Chessin

1997-01-01

297

FOREWORD: 26th IAHR Symposium on Hydraulic Machinery and Systems  

NASA Astrophysics Data System (ADS)

The 26th IAHR Symposium on Hydraulic Machinery and Systems, will be held in Beijing, China, 19-23 August 2012. It is jointly organized by Tsinghua University, State Key Laboratory of Hydro Science and Hydraulic Engineering, China, Jiangsu University, Xi'an University of Technology, China Agricultural University, National Engineering Research Center of Hydropower Equipment and Dongfang Electric Machinery Co., Ltd. It is the second time that China hosts such a symposium. By the end of 2011, the China electrical power system had a total of 1 050 GW installed power, out of which 220 GW was in hydropower plants. The energy produced in hydropower facilities was 662.6 TWh from a total of 4,720 TWh electrical energy production in 2011. Moreover, in 2020, new hydropower capacities are going to be developed, with a total of 180 GW installed power and an estimated 708 TWh/year energy production. And in 2011, the installed power of pumped storage stations was about 25GW. In 2020, the data will be 70GW. At the same time, the number of pumps used in China is increasing rapidly. China produces about 29,000,000 pumps with more than 220 series per year. By the end of 2011, the Chinese pumping system has a total of 950 GW installed power. The energy consumed in pumping facilities was 530 TWh in 2011. The pump energy consumption accounted for about 12% of the national electrical energy production. Therefore, there is a large market in the field of hydraulic machinery including water turbines, pump turbines and a variety of pumps in China. There are also many research projects in this field. For example, we have conducted National Key Research Projects on 1000 MW hydraulic turbine, and on the pump turbines with high head, as well as on the large capacity pumps for water supply. Tsinghua University of Beijing is proud to host the 26th IAHR Symposium on Hydraulic Machinery and Systems. Tsinghua University was established in 1911, after the founding of the People's Republic of China. It was molded into a polytechnic institute focusing on engineering in the nationwide restructuring of universities and colleges undertaken in 1952. At present, the university has 14 schools and 56 departments with faculties in science, engineering, humanities, law, medicine, history, philosophy, economics, management, education and art. The University now has over 25 900 students, including 13 100 undergraduates and 12 800 graduate students. As one of China's most renowned universities, Tsinghua has become an important institution for fostering talents and scientific research. The International Association of Hydro-Environment Engineering and Research (IAHR) particularly promotes the advancement and exchange of knowledge through working groups, specialty symposia, congresses, and publications on water resources, river and coastal hydraulics, risk analysis, energy, environment, disaster prevention, and industrial processes. The IAHR Committee on Hydraulic Machinery and Systems deals with the advancement of technology associated with the understanding of steady and unsteady flow characteristics in hydraulic machinery and conduit systems connected to the machinery. The technology elements include the fluid behaviour within machine components, hydro-elastic behaviour of machine components, cavitation and two phase flow in turbines and pumps, hydraulic machine and plant control systems, the use of hydraulic machines to improve water quality, and even considerations to improve fish survival in their passage through hydro plants. The main emphases of the IAHR Committee on Hydraulic Machinery and Systems are to stimulate research and understanding of the technologies associated with hydraulic machinery and to promote interaction between the machine designers, machine users, the academic community, and the community as a whole. Hydraulic machinery is both cost effective and environmentally friendly. The goals of the IAHR Committee on Hydraulic Machinery and Systems are to improve the value of hydraulic machinery to the end user, to the societies, and to improve societies u

Wu, Yulin; Wang, Zhengwei; Liu, Shuhong; Yuan, Shouqi; Luo, Xingqi; Wang, Fujun

2012-11-01

298

Life-Cycle Cost Sensitivity to Battery-Pack Voltage of an HEV  

Microsoft Academic Search

A detailed component performance, ratings, and cost study was conducted on series and parallel hybrid electric vehicle (HEV) configurations for several battery pack and main electric traction motor voltages while meeting stringent Partnership for a New Generation of Vehicles (PNGV) power delivery requirements. A computer simulation calculated maximum current and voltage for each component as well as power and fuel

John W. McKeever; Sujit Das; Leon M. Tolbert; Laura D. Marlino; Ashok Nedungadi

2000-01-01

299

Design Packing to Safely Mail Raw Spaghetti  

NSDL National Science Digital Library

Students use their creative skills to determine a way to safely mail raw (dry, uncooked) spaghetti using only the provided materials. To test the packing designs, the spaghetti is mailed through the postal system and evaluated after delivery.

Center For Engineering Educational Outreach

300

A Versatile, Automatic Chromatographic Column Packing Device  

ERIC Educational Resources Information Center

Describes an inexpensive apparatus for packing liquid and gas chromatographic columns of high efficiency. Consists of stainless steel support struts, an Automat Getriebmotor, and an associated three-pulley system capable of 10, 30, and 300 rpm. (MLH)

Barry, Eugene F.; And Others

1977-01-01

301

Laboratory Evaluation of Australian Ration Packs.  

National Technical Information Service (NTIS)

Results of analyses of ration pack items of the 1976/77 packaging programme are presented. Energy values are reported in Kilojoules. Some of the rations have become nutritionally unbalanced, particularly with respect to protein content. Total energy value...

P. E. Body C. H. Forbes-Ewan

1978-01-01

302

Field Evaluation of Australian Ration Packs.  

National Technical Information Service (NTIS)

Troop feeding trials were conducted to determine the consumer acceptability and Service suitability of the Patrol Ration (One Man) and Combat Ration (One Man) packs on issue to Australian Servicemen. These trials were superimposed upon field exercises whi...

W. E. Badcock D. J. Lichtenstein

1978-01-01

303

Universal structural characteristics of planar granular packs.  

PubMed

The dependence of structural self-organization of granular materials on preparation and grain parameters is key to predictive modeling. We study 60 different mechanically equilibrated polydisperse disc packs, generated numerically by two protocols. We show that, for same-variance disc size distributions (DSDs), (1) the mean coordination number of rattler-free packs versus the packing fraction is a function independent of initial conditions, friction, and the DSD, and (2) all quadron volume and cell order distributions collapse to universal forms, also independent of the above. This apparent universality suggests that, contrary to common wisdom, equilibrated granular structures may be determined mainly by the packing protocol and higher moments of the DSD. PMID:24655281

Matsushima, Takashi; Blumenfeld, Raphael

2014-03-01

304

A 6-DOF vibration isolation system for hydraulic hybrid vehicles  

NASA Astrophysics Data System (ADS)

This paper presents the results of vibration isolation analysis for the pump/motor component of hydraulic hybrid vehicles (HHVs). The HHVs are designed to combine gasoline/diesel engine and hydraulic power in order to improve the fuel efficiency and reduce the pollution. Electric hybrid technology is being applied to passenger cars with small and medium engines to improve the fuel economy. However, for heavy duty vehicles such as large SUVs, trucks, and buses, which require more power, the hydraulic hybridization is a more efficient choice. In function, the hydraulic hybrid subsystem improves the fuel efficiency of the vehicle by recovering some of the energy that is otherwise wasted in friction brakes. Since the operation of the main component of HHVs involves with rotating parts and moving fluid, noise and vibration are an issue that affects both passengers (ride comfort) as well as surrounding people (drive-by noise). This study looks into the possibility of reducing the transmitted noise and vibration from the hydraulic subsystem to the vehicle's chassis by using magnetorheological (MR) fluid mounts. To this end, the hydraulic subsystem is modeled as a six degree of freedom (6-DOF) rigid body. A 6-DOF isolation system, consisting of five mounts connected to the pump/motor at five different locations, is modeled and simulated. The mounts are designed by combining regular elastomer components with MR fluids. In the simulation, the real loading and working conditions of the hydraulic subsystem are considered and the effects of both shock and vibration are analyzed. The transmissibility of the isolation system is monitored in a wide range of frequencies. The geometry of the isolation system is considered in order to sustain the weight of the hydraulic system without affecting the design of the chassis and the effectiveness of the vibration isolating ability. The simulation results shows reduction in the transmitted vibration force for different working cycles of the regenerative system.

Nguyen, The; Elahinia, Mohammad; Olson, Walter W.; Fontaine, Paul

2006-04-01

305

Pliability of hydraulic connectors of mineshaft equipment  

SciTech Connect

The authors present a mathematical formulation for comparatively assessing the pliability, hydraulic conductivity, and performance of hydraulic hoses for underground cutter loaders for the purpose of optimizing and simplifying the selection and sizing of the appropriate hydraulic connector.

Ovsyannikov, P.A.; Golubev, S.M.; Karalyus, A.A.

1987-09-01

306

Monument Creek hydraulics project  

NSDL National Science Digital Library

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

Leonard, Eric

307

Liquid distribution studies in packed beds  

SciTech Connect

Recent research has shown that liquid distribution is even more important to the apparent efficiency of packed columns than was previously believed. An ''Adjustable Liquid Distributor'' which allows distribution to be changed with the column in operation has been designed and is being used to gain more insight into packed column operation. Preliminary conclusions are that discontinuities and zonal flows have the most severe impact on efficiency.

Kunesh, J.G.; Lahm, L.L.; Yanagi, T.

1985-01-01

308

Measuring the ordering of closely packed particles  

NASA Astrophysics Data System (ADS)

We look at irregularity and phase transitions in two-dimensional patterns. Two independent methods are provided for identifying and measuring hexagonal close packing of particles. We implemented these methods on images of melting colloidal films at different melting processes. We could easily spot various defects in the hexagonal crystal film. The feasibility of the methods is also demonstrated on human retinal images, for measuring the unit cell size and fraction of close-packed cone photoreceptors.

Meitav, Nizan; Ribak, Erez N.

2011-11-01

309

NEW TEACHER WELCOME PACK: HIGH SCHOOL  

NSDL National Science Digital Library

Assortment of "Best Selling" books for High School Science Teachers. Pack includes the following books. Investigating Safely, Science Educator's Guide to Laboratory Assessment, How to Write to Learn Science, Science as Inquiry in the Secondary Setting, and The Biologist's Handbook. Books are packed into a waterproof, nylon briefcase with handle and shoulder strap. Front flap of briefcase is printed with the NSTA logo. Includes free sample of the journal, The Science Teacher .

1900-01-01

310

NEW TEACHER WELCOME PACK: MIDDLE SCHOOL  

NSDL National Science Digital Library

Assortment of "Best Selling" books for Middle School Science Teachers. Pack includes the following books. Help! I'm Teaching Middle School Science, Exemplary Science Grades 5-8, Uncovering Student Ideas in Science, Volume 2, Doing Good Science in Middle School, Stop Faking It: Force and Motion. Books are packed into a waterproof, nylon briefcase with handle and shoulder strap. Front flap of briefcase is printed with the NSTA logo. Includes a free sample of the journal, Science Scope .

1900-01-01

311

Hydraulically actuated well shifting tool  

SciTech Connect

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.

Roth, B.A.

1992-10-20

312

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

NASA Astrophysics Data System (ADS)

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.

Lin, Tianliang; Wang, Qingfeng

2012-11-01

313

Decontamination of pesticide packing using ionizing radiation  

NASA Astrophysics Data System (ADS)

The Brazilian agriculture activities have consumed about 288,000 tons of pesticides per year conditioned in about 107,000,000 packing with weight of approximately 23,000 tons. The discharge of empty plastic packing of pesticides can be an environmental concern causing problems to human health, animals, and plants if done without inspection and monitoring. The objective of this work is to study the ionizing radiation effect in the main pesticides used in Brazil for plastic packing decontamination. Among the commercial pesticides, chlorpyrifos has significant importance because of its wide distribution and extensive use and persistence. The radiation-induced degradation of chlorpyrifos in liquid samples and in polyethylene pack was studied by gamma radiolysis. Packing of high-density polyethylene (HDPE) three layer coextruded, named COEX, contaminated with chlorpyrifos, were irradiated using both a multipurpose Co-60 gamma irradiator and a gamma source with 5000 Ci total activity Gamma cell type. The chemical analysis of the chlorpyrifos was made using a gas chromatography associated to the Mass Spectrometry—GCMS from Shimadzu Model QP 5000. Gamma radiation was efficient for removing chlorpyrifos from the plastic packing, in all studied cases.

Duarte, C. L.; Mori, M. N.; Kodama, Yasko; Oikawa, H.; Sampa, M. H. O.

2007-11-01

314

Coarse coal hydraulic transport  

SciTech Connect

Discusses the development of coarse coal pipeline technology requiring a minimum of product size reduction. Initial concentration on continuous face haulage and later on mainline haulage areas led eventually to the system in operation at Loveridge mine in West Virginia. Key features of the hydraulic transport system (as shown in diagram) include the pump house, vertical hoisting, overland slurry lines, a preparation/ dewatering plant, a continuous miner, a coal crusher/injection vehicle, a flexible hose hauler, a rigid slurry line, a longwall injection station, and a slurry storage/reclaim system. Explains that the system was built primarily to serve a longwall face, but it also handles coal from 2 continuous miners on longwall development work.

Petry, E.F.

1982-10-01

315

Dielectric Properties of Close-Packed Disordered Suspensions  

NASA Astrophysics Data System (ADS)

Multiple scattering techniques are used to calculate the dielectric properties of composites, specifically, close-packed disordered suspensions. Composites are usually described using single-site, long-wavelength approximations which are not applicable for either close-packed or disordered systems. In a suspension, the dielectric properties can be described in terms of electromagnetic waves multiply scattered from the inclusions and, therefore, we can use the power of Multiple-Scattering Theory together with Roth's Effective-Medium Approximation (EMA). The EMA goes beyond previous approximations as it includes particle size effects and local field fluctuations. We apply the EMA to two types of suspensions: (1) strong scattering systems of metal spheres embedded in insulating hosts and (2) a weak scattering system of pressed Al(,2)O(,3) particles. The EMA reproduces the basic features of the relevant experimental results better than other approximations. In order to further explore the utility of the EMA, we examine a model system of a Drude metal in an insulating host. The trends observed in the EMA results are those expected for a close -packed composite on the basis of general theoretical arguments.

Davis, Victoria Ann

316

Perchlorate remediation using packed-bed bioreactors and electricity generation in microbial fuel cells (MFCs)  

NASA Astrophysics Data System (ADS)

Two pilot-scale fixed bed bioreactors were operated in continuous mode in order to treat groundwater contaminated by perchlorate. The bioreactors were constructed and operated side-by-side at the Texas Street Well Facility in Redlands, California. Each reactor was packed with either sand or plastic media. A perchlorate-reducing bacterium, Dechlorosoma sp. KJ, was used to inoculate the bioreactors. Perchlorate was successfully removed down to a non-detectable level (<4mug/L) in both bioreactors with acetate as a carbon source and nutrients at loading rates less than 0.063 L/s (1 gpm; 0.34 L/m2s). The sand medium bioreactor could achieve complete-perchlorate removal up to flow rate of 0.126 L/s. A regular backwashing cycle (once a week) was an important factor for completely removing perchlorate in groundwater. Power generation directly from pure or mixed organic matter was examined using microbial fuel cells (MFCs), which were run either in batch or continuous mode. In batch experiments, both a pure culture (Geobactor metallireducens) and a mixed culture (wastewater inoculum) were used as the biocatalyst, and acetate was added as substrate in the anode chamber of the MFC. Power output in a membrane MFC with either inoculum was essentially the same, with 40 +/- 1 mW/m2 for G. metallireducens and 38 +/- 1 mW/m2 for mixed culture. A different type of the MFC containing a salt bridge instead of a membrane system was examined to generate power using the same substrate and pure culture as used in the membrane MFC. Power output in the salt bridge MFC was 2.2 mW/m 2. It was found that the lower power output was directly attributed to the higher internal resistance of the salt bridge system (19920 +/- 50 O) in comparison with that of the membrane system (1286 +/- 1 O). Continuous electricity generation was examined in a flat plate microbial fuel cell (FPMFC) using domestic wastewater and specific organic substrates. The FPMFC, containing a combined electrode/proton exchange membrane (PEM), was initially acclimated for one month to domestic wastewater, and then was operated as a plug flow reactor system. Power density using domestic wastewater as a substrate was 72 +/- 1 mW/m2 at a liquid flow rate of 0.39 mL/min (1.1 hr hydraulic retention time, HRT), and COD removal was 42%. At a longer HRT of 4.0 hr, the COD removal increased to 79%, and power density was 43 mW/m2. Several organic compounds (about 1000 mg-COD/L) also generated high power densities including: glucose (212 +/- 2 mW/m2), acetate (286 +/- 3 mW/m2), butyrate (220 +/- 1 mW/m2), dextran (150 +/- 1 mW/m 2), and starch (242 +/- 3 mW/m2). Therefore, it was shown that power could be successfully generated in a continuous-mode MFC with a variety of organic substrates. Animal wastewater was also tested as substrate to generate power in an air-cathode single chamber MFC operated in batch mode. This preliminary experiment demonstrated that power generation could be sustained with animal wastewater and that wastewater strength and odors were substantially reduced in the reactor after only one day of operation.

Min, Booki

317

Hydraulic system for a ratio change transmission  

DOEpatents

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.

Kalns, Ilmars (Northville, MI)

1981-01-01

318

Hydraulic conductivity of compacted zeolites.  

PubMed

Hydraulic conductivities of compacted zeolites were investigated as a function of compaction water content and zeolite particle size. Initially, the compaction characteristics of zeolites were determined. The compaction test results showed that maximum dry unit weight (?(dmax)) of fine zeolite was greater than that of granular zeolites. The ?(dmax) of compacted zeolites was between 1.01 and 1.17 Mg m(-3) and optimum water content (w(opt)) was between 38% and 53%. Regardless of zeolite particle size, compacted zeolites had low ?(dmax) and high w(opt) when compared with compacted natural soils. Then, hydraulic conductivity tests were run on compacted zeolites. The hydraulic conductivity values were within the range of 2.0 × 10(-3) cm s(-1) to 1.1 × 10(-7) cm s(-1). Hydraulic conductivity of all compacted zeolites decreased almost 50 times as the water content increased. It is noteworthy that hydraulic conductivity of compacted zeolite was strongly dependent on the zeolite particle size. The hydraulic conductivity decreased almost three orders of magnitude up to 39% fine content; then, it remained almost unchanged beyond 39%. Only one report was found in the literature on the hydraulic conductivity of compacted zeolite, which is in agreement with the findings of this study. PMID:23460541

Oren, A Hakan; Ozdamar, Tu?çe

2013-06-01

319

Hydraulic design of Three Gorges right bank powerhouse turbine for improvement of hydraulic stability  

NASA Astrophysics Data System (ADS)

This paper presents the hydraulic design of Three Gorges Right Bank Powerhouse turbine for improvement of hydraulic stability. The technical challenges faced in the hydraulic design of the turbine are given. The method of hydraulic design for improving the hydraulic stability and particularly for eliminating the upper part load pressure pulsations is clarified. The final hydraulic design results of Three Gorges Right Bank Powerhouse turbine based on modern hydraulic design techniques are presented.

Shi, Q.

2010-08-01

320

Electrokinetic high pressure hydraulic system  

DOEpatents

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.

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

2000-01-01

321

Hydraulic characteristics of biological filters.  

PubMed

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

Muslu, Y

1991-01-01

322

Development of Cushioning Data for Fast Pack Program.  

National Technical Information Service (NTIS)

The Star pack design of Fast Pack containers currently being used in the Air Force Fast Pack program will provide the packaging requirements for numerous items requiring protection from shock and vibration. To insure the effective use of these Star pack c...

R. S. Larsen

1973-01-01

323

48 CFR 1846.672-6 - Packing list instructions.  

Code of Federal Regulations, 2013 CFR

...2013-10-01 2013-10-01 false Packing list instructions. 1846.672-6...and Receiving Reports 1846.672-6 Packing list instructions. Copies of the MIRR may be used as a packing list. The packing list copies...

2013-10-01

324

Packed bed carburization of tantalum and tantalum alloy  

Microsoft Academic Search

Packed bed carburization of a tantalum or tantalum alloy object is disclosed. A method for producing corrosion-resistant tantalum or tantalum alloy objects is described. The method includes the steps of placing the object in contact with a carburizing pack, heating the packed object in vacuum furnace to a temperature whereby carbon from the pack diffuses into the object forming grains

P. C. Lopez; P. J. Rodriguez; R. A. Pereyra

1999-01-01

325

Packed bed carburization of tantalum and tantalum alloy  

Microsoft Academic Search

Packed bed carburization of a tantalum or tantalum alloy object. A method for producing corrosion-resistant tantalum or tantalum alloy objects is described. The method includes the steps of placing the object in contact with a carburizing pack, heating the packed object in vacuum furnace to a temperature whereby carbon from the pack diffuses into the object forming grains with tantalum

Peter C. Lopez; Patrick J. Rodriguez; Ramiro A. Pereyra

1999-01-01

326

Laboratory imaging of stimulation fluid displacement from hydraulic fractures  

SciTech Connect

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.

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

1996-11-01

327

Effects of Nasopore Packing on Dacryocystorhinostomy  

PubMed Central

Purpose To investigate the effects of placement of the absorbable packing material Nasopore at the anastomosis site of newly formed mucosal flaps on postoperative re-bleeding, discomfort, and on the success rate of dacryocystorhinostomy (DCR). Methods A review of the medical records of patients with primary acquired nasolacrimal duct obstruction that underwent external or endonasal DCR by a single surgeon was performed. The degree of re-bleeding, discomfort, and postoperative results, including anatomical success, functional success and postoperative nasal findings such as granulation, synechiae, and membrane formation were compared in patients whose anastomosis site was packed with either Nasopore or Merocel, a non-absorbable packing material. Results A total of 77 patients (101 eyes) were included. Of the 101 eyes, 30 were packed with Nasopore, while 71 were packed with Merocel. The Nasopore group showed significantly better results than the Merocel group in the degree of re-bleeding and the level of patient discomfort (p = 0.000, 0.039, respectively; Pearson's chi-square test), whereas there were no statistically significant differences between the two groups in postoperative anatomical and functional success (p > 0.05). Conclusions Nasopore significantly reduced postoperative nasal re-bleeding and patient discomfort during the early post-surgical period, but failed to show an effect on the postoperative anatomical and functional success of DCR.

Jang, Sun Young; Lee, Kyou Ho; Lee, Sang Yeul

2013-01-01

328

2D packing using the Myriad framework  

NASA Astrophysics Data System (ADS)

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.

Chatburn, Luke T.; Batchelor, Bruce G.

2004-02-01

329

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

PubMed

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

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

2014-05-01

330

The Virtual Laboratory of Machine Tool Hydraulics  

NSDL National Science Digital Library

The Virtual Laboratory of Machine Tool Hydraulics is an interactive, web-based graphic animation of machine tool hydraulics. It includes fundamentals, troubleshooting, problem-solving, and interactive demonstrations of hydraulic circuits and components. This is a great interactive activity for those interested in learning the fundamental concepts of hydraulic systems.

Song, Xueshu

2009-10-29

331

Cold regions hydrology and hydraulics  

SciTech Connect

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.

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

1990-01-01

332

Applying GIS to Hydraulic Analysis  

Microsoft Academic Search

HEC-RAS is the one of popular programs that are made for hydraulic analysis. This is designed to perform one-dimensional hydraulic calculations for a full network of natural and constructed channels. In spite of many benefit of this program, some problems are founded while running HEC-RAS. The most significant problem is the geometric input data. This procedure requires lots of manual

Chae Kwan

333

Method for packed column separations and purifications  

DOEpatents

The invention encompasses a method of packing and unpacking a column chamber. A mixture of a fluid and a matrix material are introduced through a column chamber inlet so that the matrix material is packed within a column chamber to form a packed column. The column chamber having the column chamber inlet or first port for receiving the mixture further has an outlet port and an actuator port. The outlet port is partially closed for capturing the matrix material and permitting the fluid to flow therepast by rotating relative one to the other of a rod placed in the actuator port. Further rotation relative one to the other of the rod and the column chamber opens the outlet and permits the matrix material and the fluid to flow therethrough thereby unpacking the matrix material from the column chamber.

Holman, David A. (Richland, WA); Bruckner-Lea, Cynthia J. (Richland, WA); Brockman, Fred J. (Kennewick, WA); Chandler, Darrell P. (Richland, WA)

2006-08-15

334

Spontaneous crystallization in athermal polymer packings.  

PubMed

We review recent results from extensive simulations of the crystallization of athermal polymer packings. It is shown that above a certain packing density, and for sufficiently long simulations, all random assemblies of freely-jointed chains of tangent hard spheres of uniform size show a spontaneous transition into a crystalline phase. These polymer crystals adopt predominantly random hexagonal close packed morphologies. An analysis of the local environment around monomers based on the shape and size of the Voronoi polyhedra clearly shows that Voronoi cells become more spherical and more symmetric as the system transits to the ordered state. The change in the local environment leads to an increase in the monomer translational contribution to the entropy of the system, which acts as the driving force for the phase transition. A comparison of the crystallization of hard-sphere polymers and monomers highlights similarities and differences resulting from the constraints imposed by chain connectivity. PMID:23263666

Karayiannis, Nikos Ch; Foteinopoulou, Katerina; Laso, Manuel

2012-01-01

335

Spontaneous Crystallization in Athermal Polymer Packings  

PubMed Central

We review recent results from extensive simulations of the crystallization of athermal polymer packings. It is shown that above a certain packing density, and for sufficiently long simulations, all random assemblies of freely-jointed chains of tangent hard spheres of uniform size show a spontaneous transition into a crystalline phase. These polymer crystals adopt predominantly random hexagonal close packed morphologies. An analysis of the local environment around monomers based on the shape and size of the Voronoi polyhedra clearly shows that Voronoi cells become more spherical and more symmetric as the system transits to the ordered state. The change in the local environment leads to an increase in the monomer translational contribution to the entropy of the system, which acts as the driving force for the phase transition. A comparison of the crystallization of hard-sphere polymers and monomers highlights similarities and differences resulting from the constraints imposed by chain connectivity.

Karayiannis, Nikos Ch.; Foteinopoulou, Katerina; Laso, Manuel

2013-01-01

336

Excitations of ellipsoid packings near jamming  

NASA Astrophysics Data System (ADS)

We study the vibrational modes of three-dimensional jammed packings of soft ellipsoids of revolution as a function of particle aspect ratio ? and packing fraction. At the jamming transition for ellipsoids, as distinct from the idealized case using spheres where ?=1, there are many unconstrained and nontrivial rotational degrees of freedom. These constitute a set of zero-frequency modes that are gradually mobilized into a new rotational band as |?-1| increases. Quite surprisingly, as this new band is separated from zero frequency by a gap, and lies below the onset frequency for translational vibrations, ?*, the presence of these new degrees of freedom leaves unaltered the basic scenario that the translational spectrum is determined only by the average contact number. Indeed, ?* depends solely on coordination as it does for compressed packings of spheres. We also discuss the regime of large |?-1|, where the two bands merge.

Zeravcic, Z.; Xu, N.; Liu, A. J.; Nagel, S. R.; van Saarloos, W.

2009-07-01

337

Safety considerations for fabricating lithium battery packs  

NASA Astrophysics Data System (ADS)

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.

Ciesla, J. J.

1986-09-01

338

Safety considerations for fabricating lithium battery packs  

NASA Technical Reports Server (NTRS)

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.

Ciesla, J. J.

1986-01-01

339

Active cooling debris bypass fin pack  

US Patent & Trademark Office Database

Aspects of the disclosure relate generally to active cooling or removing heat generated by a processor in a computing device. More specifically, a cooling system in a computing device may include a heatpipe which moves heat along a fin pack. The fin pack may include top and bottom ends as well as a plurality of fins. The fins may extend only a portion of the way between the ends thus creating an air duct. The air duct may allow debris to move along an edge of the fin and out of the computing device. The fins may also be curved to promote the forcing of debris through the fin pack while still allowing the heat to be expelled through the fins.

2014-04-15

340

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

NASA Technical Reports Server (NTRS)

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.

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

1998-01-01

341

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

SciTech Connect

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)

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

342

Sequential random packings of spheres and ellipsoids  

NASA Astrophysics Data System (ADS)

We introduce sequential random procedures to pack polydisperse spheres and ellipsoids. For spheres, we generalize the recent study of random space-filling bearings to a situation, where the offset varies randomly and show that it reproduces well the fractal dimension observed in real fault gouges. For ellipsoids, we show how to use variational methods to determine both translations and rotations for packing them sequentially. The algorithm considers an external gravitational field and retrieves the contact points according to the rotations and translations obtained from two variational procedures.

Lind, Pedro G.

2009-06-01

343

A PDMS lipseal for hydraulic and pneumatic microactuators  

Microsoft Academic Search

Recent publications show that hydraulic and pneumatic microactuators offer superior power and force densities at the microscale. The main technological barrier for the development of these actuators is the lack of microseal technologies. These seals must prevent the driving fluid leaking to the outside world without introducing friction. This paper presents a method to fabricate miniature lipseals in batch quantities.

Michaël DeVolder; Frederik Ceyssens; Dominiek Reynaerts; Robert Puers

2007-01-01

344

Fault diagnosis of water hydraulic actuators under some simulated faults  

Microsoft Academic Search

Water hydraulics captured the imagination of engineers some 2500 years ago and recently it has revived to become a powerful alternative in areas where the environment and health are of great concern. Previously, this field of knowledge suffered some setbacks as technology was still at its developing stage, but with better tolerances and the availability of better materials, this technology

Alfred C. H. Tan; Patrick S. K. Chua; G. H. Lim

2003-01-01

345

Thermal Hydraulic Analysis of MH-1A Core 5.  

National Technical Information Service (NTIS)

This report presents the thermal hydraulic analysis of Core 5 for the MH-1A Floating Barge Nuclear Power Plant. The primary purpose of this study is to demonstrate that the reactor core is capable of meeting normal steady-state and transient performance r...

H. C. Gignilliat P. E. Francisco T. M. Rotchford R. M. DeVault

1974-01-01

346

View south of hydraulic hammer in boilermakers shop (probably the ...  

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

View south of hydraulic hammer in boilermakers shop (probably the oldest piece of equipment in the yard, originally powered by steam) nameplate: United Engineers and FDRY. Co. Pittsburgh, Pa, USA Davy Brothers LTD. Patents - Aug 1, 1905, Feb, 1901, Sept 8, 1908 - 10000 lbs. - Naval Base Philadelphia-Philadelphia Naval Shipyard, Structure Shop, League Island, Philadelphia, Philadelphia County, PA

347

Hydraulic tests of emergency cooling system: L-Area  

SciTech Connect

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.

Hinton, J H

1988-01-01

348

On Ulam's packing conjecture: is the ball the worst shape for packing?  

NASA Astrophysics Data System (ADS)

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. In two dimensions, a regular octagon whose corners have been smoothed to arcs of hyperbolas is known to be a local minimum of the optimal packing fraction and the circle is known to not be a local minimum. In three dimensions, we show that the ball is a local minimum: it is the worst packing shape among shapes of sufficiently low asphericity. We also discuss related results in higher dimensions and for the worst shape for other optimal arrangement problems.

Kallus, Yoav

2013-03-01

349

Pressure drop of internals for packed columns  

Microsoft Academic Search

Because of their low pressure drop per equilibrium stage, random and particularly structured packings are frequently used in vacuum distillation. For applications requiring operation at absolute pressures below 100mbar usually the total allowable pressure drop is specified. Demanding separations require frequent collection and redistribution of liquid. This means dealing with an additional source of pressure drop which is usually ignored,

A. Rix; Z. Olujic

2008-01-01

350

Name That Shell! ClassPack  

NSDL National Science Digital Library

Using Picture-Perfect Science Lessons 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 unmatched time-saver and a great deal. This Cla

2010-04-15

351

Parallel Approximation Algorithms for Bin Packing.  

National Technical Information Service (NTIS)

The authors study the parallel complexity of polynomial heuristics for the bin packing problem. They show that some well-known (and simple) methods like first-fit-decreasing are p-complete, and it is hence very unlikely that they can be efficiently parall...

R. J. Anderson E. W. Mayr M. K. Warmuth

1988-01-01

352

Vertex packings: Structural properties and algorithms  

Microsoft Academic Search

We consider a binary integer programming formulation (VP) for the weighted vertex packing problem in a simple graph. A sufficient “local” optimality condition for (VP) is given and this result is used to derive relations between (VP) and the linear program (VLP) obtained by deleting the integrality restrictions in (VP). Our most striking result is that those variables which assume

G. L. Nemhauser

1975-01-01

353

Porous bead packings for gas chromatography  

NASA Technical Reports Server (NTRS)

Porous polyaromatic packing beads have low polarity, high efficiency, short retention time, and may be synthesized in size range of 50 to 150 micrometers (100 to 270 mesh). Mechanically strong beads may be produced using various materials depending on elements and compounds to be identified.

Pollock, G. E.; Woeller, F. H.

1979-01-01

354

PackBot EOD firing system  

Microsoft Academic Search

The PackBot EOD firing system was developed to allow the safe initiation of disruptors used to disable improvised explosive devices (IEDs). Safety is assured despite the use of communication links shared by possibly insecure computers on UGVs and control stations. This specific firing system was developed to enforce a particular EOD operational protocol where a single operator is responsible for

Pavlo Rudakevych; Mike Ciholas

2005-01-01

355

Leadership in Wolf, Canis lupus, Packs  

NSDL National Science Digital Library

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.

Mech, L. D.

2000-01-01

356

PERM for solving circle packing problem  

Microsoft Academic Search

In this paper, we develop a new algorithm that incorporates the improved PERM into an already existing simple deterministic heuristic, the principle of maximum cave degree for corner-occupying actions, to solve the problem of packing equal or unequal circles into a larger circle container. We compare the performance of our algorithm on several problem instances taken from the literature with

Lü Zhipeng; Wenqi Huang

2008-01-01

357

Elastic moduli of cemented sphere packs  

Microsoft Academic Search

We present a method for estimating the effective elastic moduli of a dense random pack of identical elastic spheres with elastic binder (cement). The cement concentration in the pore space varies from a few percent (where it fills the space at grain contacts) to 100%. To construct the solution we start at a small cement concentration value where the effective

Jack Dvorkin; Jim Berryman; Amos Nur

1999-01-01

358

Sheep in a Jeep ClassPack  

NSDL National Science Digital Library

Using Picture-Perfect Science Lessons 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 unmatched time-saver and a great deal. This Cla

2010-04-21

359

Parametric Studies on the Load-Deflection Characteristics of Hydraulic Snubbers.  

National Technical Information Service (NTIS)

Hydraulic snubbers are extensively used in the nuclear power industry for supporting high energy piping systems subjected to dynamic loadings. These devices allow the piping system to displace freely under slowly applied loads, but lock up under sudden ex...

M. Subudhi J. B. P. Curreri M. Hartzman

1984-01-01

360

Hand-Held Hydraulic Rock Drill and Seafloor Fasteners for Use by Divers.  

National Technical Information Service (NTIS)

Underwater construction operations require an improved diver-operable rock drill and efficient and reliable seafloor rock fasteners. An experimental hydraulically powered rock drill was fabricated from commercially available components. The results from t...

R. L. Brackett A. M. Parisi

1975-01-01

361

Barrier properties of k-mer packings  

NASA Astrophysics Data System (ADS)

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.

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

2014-08-01

362

Fluid Power  

NSDL National Science Digital Library

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.

Leske, Cavin.

2002-01-01

363

Application study of magnetic fluid seal in hydraulic turbine  

NASA Astrophysics Data System (ADS)

The waterpower resources of our country are abundant, and the hydroelectric power is developed, but at present the main shaft sealing device of hydraulic turbine is easy to wear and tear and the leakage is great. The magnetic fluid seal has the advantages of no contact, no wear, self-healing, long life and so on. In this paper, the magnetic fluid seal would be used in the main shaft of hydraulic turbine, the sealing structure was built the model, meshed the geometry, applied loads and solved by using MULTIPHYSICS in ANSYS software, the influence of the various sealing structural parameters such as tooth width, height, slot width, sealing gap on the sealing property were analyzed, the magnetic fluid sealing device suitable for large-diameter shaft and sealing water was designed, the sealing problem of the hydraulic turbine main shaft was solved effectively which will bring huge economic benefits.

Yu, Z. Y.; Zhang, W.

2012-11-01

364

Pressure solution creep of random packs of spheres  

NASA Astrophysics Data System (ADS)

performed numerical calculations of compaction in aggregates of spherical grains, using Lehner and Leroy's (2004, hereinafter LL) constitutive model of pressure solution at grain contacts. That model is founded on a local definition of the thermodynamic driving force and leads to a fully coupled formulation of elastic deformation, dissolution, and diffusive transport along the grain boundaries. The initial geometry of the aggregate was generated by random packing of spheres with a small standard deviation of the diameters. During the simulations, isostatic loading was applied. The elastic displacements at the contacts were calculated according to Digby's (1981) nonlinear contact force model, and deformation by dissolution was evaluated using the LL formulation. The aggregate strain and porosity were tracked as a function of time for fixed temperature, applied effective pressure, and grain size. We also monitored values of the average and standard deviation of total load at each contact, the coordination number for packing, and the statistics of the contact dimensions. Because the simulations explicitly exclude processes such as fracturing, plastic flow, and transport owing to surface curvature, they can be used to test the influence of relative changes in the kinetics of dissolution and diffusion processes caused by contact growth and packing rearrangements. We found that the simulated strain data could be empirically fitted by two successive power laws of the form, ?x ? t?, where ? was equal to 1 at very early times, but dropped to as low as 0.3 at longer times. The apparent sensitivity of strain rate to stress found in the simulations was much lower than predicted from constitutive laws that assume a single dominant process driven by average macroscopic loads. Likewise, the apparent activation enthalpy obtained from the simulated data was intermediate between that assumed for dissolution and diffusion, and, further, tended to decrease with time. These results are similar to the experimental observations of Visser et al.'s (2012), who used an aggregate geometry and physical conditions closely resembling the present numerical simulations.

Bernabé, Y.; Evans, B.

2014-05-01

365

Development of the Packed Bed Reactor ISS Flight Experiment  

NASA Technical Reports Server (NTRS)

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.

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

2012-01-01

366

Power.  

ERIC Educational Resources Information Center

This issue addresses advantages and disadvantages of having power. Includes Web sites, CD-ROMs and software, videos, books, and additional resources with suggested age levels and disciplines as well as ideas for appropriate related activities. Sidebars discuss the power of the pen, the power of peace, and the power of the media. (LRW)

Online-Offline, 1999

1999-01-01

367

Tuning jammed frictionless disk packings from isostatic to hyperstatic  

NASA Astrophysics Data System (ADS)

We perform extensive computational studies of two-dimensional static bidisperse disk packings using two distinct packing-generation protocols. The first involves thermally quenching equilibrated liquid configurations to zero temperature over a range of thermal quench rates r and initial packing fractions followed by compression and decompression in small steps to reach packing fractions ?J at jamming onset. For the second, we seed the system with initial configurations that promote micro- and macrophase-separated packings followed by compression and decompression to ?J. Using these protocols, we generate more than 104 static packings over a wide range of packing fraction, contact number, and compositional and positional order. We find that disordered, isostatic packings exist over a finite range of packing fractions in the large-system limit. In agreement with previous calculations, the most dilute mechanically stable packings with ?min?0.84 are obtained for r>r*, where r* is the rate above which ?J is insensitive to rate. We further compare the structural and mechanical properties of isostatic versus hyperstatic packings. The structural characterizations include the contact number, several order parameters, and mixing ratios of the large and small particles. We find that the isostatic packings are positionally and compositionally disordered (with only small changes in a number of order parameters), whereas bond-orientational and compositional order increase strongly with contact number for hyperstatic packings. In addition, we calculate the static shear modulus and normal mode frequencies (in the harmonic approximation) of the static packings to understand the extent to which the mechanical properties of disordered, isostatic packings differ from partially ordered packings. We find that the mechanical properties of the packings change continuously as the contact number increases from isostatic to hyperstatic.

Schreck, Carl F.; O'Hern, Corey S.; Silbert, Leonardo E.

2011-07-01

368

7 CFR 2902.28 - Stationary equipment hydraulic fluids.  

Code of Federal Regulations, 2010 CFR

...Stationary equipment hydraulic fluids. 2902...Stationary equipment hydraulic fluids. (a...use in stationary hydraulic equipment systems...various mechanical parts, such as cylinders, pumps, valves, pistons, and...

2009-01-01

369

7 CFR 2902.28 - Stationary equipment hydraulic fluids.  

Code of Federal Regulations, 2010 CFR

...Stationary equipment hydraulic fluids. 2902...Stationary equipment hydraulic fluids. (a...use in stationary hydraulic equipment systems...various mechanical parts, such as cylinders, pumps, valves, pistons, and...

2010-01-01

370

Fluid shear influences on the performance of hydraulic flocculation systems.  

PubMed

Gravity driven hydraulic flocculators that operate in the absence of reliable electric power are better suited to meet the water treatment needs of green communities, resource-poor communities, and developing countries than conventional mechanical flocculators. However, current understanding regarding the proper design and operation of hydraulic flocculation systems is insufficient. Of particular interest is the optimal fluid shear level needed to produce low turbidity water. A hydraulic tube flocculator was used to study how fluid shear levels affect the settling properties of a flocculated alum-kaolin suspension. A Flocculation Residual Turbidity Analyzer (FReTA) was used to quantitatively compare the sedimentation velocity distributions and the post-sedimentation residual turbidities of the flocculated suspensions to see how they were affected by varying fluid shear, G, and hydraulic residence time, ?, while holding collision potential, G?, constant. Results show that floc breakup occurred at all velocity gradients evaluated. High floc settling velocities were correlated with low residual turbidities, both of which were optimized at low fluid shear levels and long fluid residence times. This study shows that, for hydraulic flocculation systems under the conditions described in this paper, low turbidity water is produced when fluid shear is kept at a minimum. Use of the product G? for design of laminar flow tube flocculators is insufficient if residual turbidity is used as the metric for performance. At any G? within the range tested in this study, best performance is obtained when G is small and ? is long. PMID:21880341

Tse, Ian C; Swetland, Karen; Weber-Shirk, Monroe L; Lion, Leonard W

2011-11-01

371

Mathematical model of hydraulic jackhammer  

SciTech Connect

A hydraulic jackhammer as shown in this paper, consists of an impact mechanism, state sensors, a slide-valve distributor, and pressure and overflow lines. The problem of designing hydraulic jackhammers is distinguished by the multiplicity of possible solutions and the need to take account of and estimate many indices. In this paper, the authors formulate a mathematical model to estimate the optimal hammer parameters at the design stage. In formulating such a model, the initial quantities are the productivity of the pump, the force applied to the handle by the operator, and the characteristics of the hammer-instrument interaction. The algorithm of the program is shown. The laws of time variation of the working-liquid pressure are shown here. The use of the mathematical model developed here offers the possibility of investigating the operation of a hydraulic jackhammer both in dynamic synthesis and in dynamic analysis.

Eshutkin, D.N.; Piven', G.G.; Grigorchak, V.S.; Ten, G.S.

1987-05-01

372

Electrokinetic high pressure hydraulic system  

DOEpatents

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.

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

373

Method for directional hydraulic fracturing  

DOEpatents

A method for directional hydraulic fracturing using borehole seals to confine pressurized fluid in planar permeable regions, comprising: placing a sealant in the hole of a structure selected from geologic or cemented formations to fill the space between a permeable planar component and the geologic or cemented formation in the vicinity of the permeable planar component; making a hydraulic connection between the permeable planar component and a pump; permitting the sealant to cure and thereby provide both mechanical and hydraulic confinement to the permeable planar component; and pumping a fluid from the pump into the permeable planar component to internally pressurize the permeable planar component to initiate a fracture in the formation, the fracture being disposed in the same orientation as the permeable planar component.

Swanson, David E. (West St. Paul, MN); Daly, Daniel W. (Crystal, MN)

1994-01-01

374

Review of computational thermal-hydraulic modeling  

SciTech Connect

Corrosion of heat transfer tubing in nuclear steam generators has been a persistent problem in the power generation industry, assuming many different forms over the years depending on chemistry and operating conditions. Whatever the corrosion mechanism, a fundamental understanding of the process is essential to establish effective management strategies. To gain this fundamental understanding requires an integrated investigative approach that merges technology from many diverse scientific disciplines. An important aspect of an integrated approach is characterization of the corrosive environment at high temperature. This begins with a thorough understanding of local thermal-hydraulic conditions, since they affect deposit formation, chemical concentration, and ultimately corrosion. Computational Fluid Dynamics (CFD) can and should play an important role in characterizing the thermal-hydraulic environment and in predicting the consequences of that environment,. The evolution of CFD technology now allows accurate calculation of steam generator thermal-hydraulic conditions and the resulting sludge deposit profiles. Similar calculations are also possible for model boilers, so that tests can be designed to be prototypic of the heat exchanger environment they are supposed to simulate. This paper illustrates the utility of CFD technology by way of examples in each of these two areas. This technology can be further extended to produce more detailed local calculations of the chemical environment in support plate crevices, beneath thick deposits on tubes, and deep in tubesheet sludge piles. Knowledge of this local chemical environment will provide the foundation for development of mechanistic corrosion models, which can be used to optimize inspection and cleaning schedules and focus the search for a viable fix.

Keefer, R.H.; Keeton, L.W.

1995-12-31

375

Extended Kalman filtering for battery management systems of LiPB-based HEV battery packs. Part 3. State and parameter estimation  

NASA Astrophysics Data System (ADS)

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, based on extended Kalman filtering (EKF), that are able to accomplish these goals for a lithium ion polymer battery pack. We expect that they will also work well on other battery chemistries. These papers cover the required mathematical background, cell modeling and system identification requirements, and the final solution, together with results. This third paper concludes the series by presenting five additional applications where either an EKF or results from EKF may be used in typical BMS algorithms: initializing state estimates after the vehicle has been idle for some time; estimating state-of-charge with dynamic error bounds on the estimate; estimating pack available dis/charge power; tracking changing pack parameters (including power fade and capacity fade) as the pack ages, and therefore providing a quantitative estimate of state-of-health; and determining which cells must be equalized. Results from pack tests are presented.

Plett, Gregory L.

376

Electokinetic high pressure hydraulic system  

DOEpatents

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.

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

2000-01-01

377

Extraction of Caprolactam with Toluene in a Pulsed Disc and Doughnut Column—Part I: Recommendation of a Model for Hydraulic Characteristics  

Microsoft Academic Search

Caprolactam, the monomer for Nylon?6, is industrially recovered from an aqueous feed containing ammonium sulphate by extraction with organic solvents like benzene, toluene, or chlorinated hydrocarbons followed by back?extraction with water. Extraction columns like the Rotating Disk Contactor and Pulsed Packed Column are industrially applied. In this paper a model is recommended for the description of the hydraulic characteristics of

M. L. van Delden; N. J. M. Kuipers; A. B. de Haan

2006-01-01

378

Pilot-scale comparison of constructed wetlands operated under high hydraulic loading rates and attached biofilm reactors for domestic wastewater treatment  

Microsoft Academic Search

Four different pilot-scale treatment units were constructed to compare the feasibility of treating domestic wastewater in the City of Heraklio, Crete, Greece: (a) a free water surface (FWS) wetland system, (b) a horizontal subsurface flow (HSF) wetland system, (c) a rotating biological contactor (RBC), and (d) a packed bed filter (PBF). All units operated in parallel at various hydraulic loading

M. S. Fountoulakis; S. Terzakis; A. Chatzinotas; H. Brix; N. Kalogerakis; T. Manios

2009-01-01

379

Effect of Styrofoam Interlayers in Fragment Witness Packs.  

National Technical Information Service (NTIS)

Witness packs are used to obtain the mass velocity distribution of fragments generated, for example, at complete perforation of a target. A witness pack consists of several metallic layers of various materials and thicknesses spaced evenly. The STANAG 419...

G. McIntosh

1999-01-01

380

VIEW NORTHEAST, WEST FRONT OF PACKING SHED (BUILDING 20) AND ...  

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

VIEW NORTHEAST, WEST FRONT OF PACKING SHED (BUILDING 20) AND BAMBOO STAND ALONG SOUTH FRONT - U.S. Plant Introduction Station, Packing Shed, 11601 Old Pond Road, Glenn Dale, Prince George's County, MD

381

11. Boiler building at west end of Packing house adjacent ...  

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

11. Boiler building at west end of Packing house adjacent to railroad tracks, looking east, northeast. - College Heights Lemon Packing House, 519-532 West First Street, Claremont, Los Angeles County, CA

382

Nonuniversality of density and disorder in jammed sphere packings  

NASA Astrophysics Data System (ADS)

We show for the first time that collectively jammed disordered packings of three-dimensional monodisperse frictionless hard spheres can be produced and tuned using a novel numerical protocol with packing density ? as low as 0.6. This is well below the value of 0.64 associated with the maximally random jammed state and entirely unrelated to the ill-defined ``random loose packing'' state density. Specifically, collectively jammed packings are generated with a very narrow distribution centered at any density ? over a wide density range ??(0.6,0.740 48...) with variable disorder. Our results support the view that there is no universal jamming point that is distinguishable based on the packing density and frequency of occurrence. Our jammed packings are mapped onto a density-order-metric plane, which provides a broader characterization of packings than density alone. Other packing characteristics, such as the pair correlation function, average contact number, and fraction of rattlers are quantified and discussed.

Jiao, Yang; Stillinger, Frank H.; Torquato, Salvatore

2011-01-01

383

Airborne asbestos exposures associated with gasket and packing replacement: A simulation study and meta-analysis.  

PubMed

Exposures to airborne asbestos during the removal and installation of internal gaskets and packing associated with a valve overhaul were characterized and compared to published data according to different variables (e.g., product, equipment, task, tool, setting, duration). Personal breathing zone and area samples were collected during twelve events simulating gasket and packing replacement, clean-up and clothing handling. These samples were analyzed using PCM and TEM methods and PCM-equivalent (PCME) airborne asbestos concentrations were calculated. A meta-analysis was performed to compare these data with airborne asbestos concentrations measured in other studies involving gaskets and packing. Short-term mechanic and assistant airborne asbestos concentrations during valve work averaged 0.013f/cc and 0.008f/cc (PCME), respectively. Area samples averaged 0.008f/cc, 0.005f/cc, and 0.003f/cc (PCME) for center, bystander, and remote background, respectively. Assuming a tradesman conservatively performs 1-3 gasket and/or packing replacements daily, an average 8-h TWA was estimated to be 0.002-0.010f/cc (PCME). Combining these results in a meta-analysis of the published exposure data showed that the majority of airborne asbestos exposures during work with gaskets and packing fall within a consistent and low range. Significant differences in airborne concentrations were observed between power versus manual tools and removal versus installation tasks. Airborne asbestos concentrations resulting from gasket and packing work during a valve overhaul are consistent with historical exposure data on replacement of asbestos-containing gasket and packing materials involving multiple variables and, in nearly all plausible scenarios, result in average airborne asbestos concentrations below contemporaneous occupational exposure limits for asbestos. PMID:24768989

Madl, Amy K; Hollins, Dana M; Devlin, Kathryn D; Donovan, Ellen P; Dopart, Pamela J; Scott, Paul K; Perez, Angela L

2014-08-01

384

Is incest common in gray wolf packs?  

USGS Publications Warehouse

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.

Smith, D.; Meier, T.; Geffen, E.; Mech, L.D.; Burch, J.W.; Adams, L.G.; Wayne, R.K.

1997-01-01

385

How relative humidity affects random packing experiments.  

PubMed

The influence of relative humidity (RH) on the extremely slow compaction dynamics of a granular assembly has been experimentally investigated. Millimeter-sized glass beads are considered. Compaction curves are fitted by stretched exponentials with characteristic time ? and exponent ?, which are seen to be deeply affected by the moisture content. A kinetic model, taking into account both triboelectric and capillary effects, is in excellent agreement with our results. It confirms the existence of an optimal condition at a relative humidity ?45% for minimizing cohesive interactions between glass beads. The exponent ? is seen to depend strongly on the diffusive character of grains and voids inside the packing: diffusion for cohesiveless particles and subdiffusion when cohesion plays a role. As a consequence, the RH represents a relevant parameter that should be reported for every experimental work on a slowly driven dense random packing. PMID:22587094

Vandewalle, N; Lumay, G; Ludewig, F; Fiscina, J E

2012-03-01

386

An alternative cooling system to enhance the safety of Li-ion battery packs  

Microsoft Academic Search

A passive thermal management system is evaluated for high-power Li-ion packs under stressful or abusive conditions, and compared with a purely air-cooling mode under normal and abuse conditions. A compact and properly designed passive thermal management system utilizing phase change material (PCM) provides faster heat dissipation than active cooling during high pulse power discharges while preserving sufficiently uniform cell temperature

Riza Kizilel; Rami Sabbah; J. Robert Selman; Said Al-Hallaj

2009-01-01

387

Gamma scanning evaluation for random packed columns  

Microsoft Academic Search

In the present study, the liquid (water) holdup distribution was measured in a packed column (7.62 cm diameter) filled with 0.9 cm glass Rashig rings using noninvasive gamma ray technique. Three different radioactive sources: 11.1 MBq 60Co (1133 keV), 74 GBq 131I (380 keV), and 740 GBq 99mTc (140 keV) with a CsI(Tl) detector coupled to a photodiode were used

Vasquez PAS; F. E. Costa; P. R. Rela; W. A. P. Calvo; G. A. C. LeRoux; M. M. Hamada

2005-01-01

388

Close Packing of Layers of Spheres  

NSDL National Science Digital Library

An animation of the close packing of layers of spheres. In this version, clicking on text links adds the second and third layers, with two options for the third layer. After both ways of adding the third layer have been explored the user has an option to go to a second version that has no text but rather allows the user to drag the layers over one another.

389

Partitioning And Packing Equations For Parallel Processing  

NASA Technical Reports Server (NTRS)

Algorithm developed to identify parallelism in set of coupled ordinary differential equations that describe physical system and to divide set into parallel computational paths, along with parts of solution proceeds independently of others during at least part of time. Path-identifying algorithm creates number of paths consisting of equations that must be computed serially and table that gives dependent and independent arguments and "can start," "can end," and "must end" times of each equation. "Must end" time used subsequently by packing algorithm.

Arpasi, Dale J.; Milner, Edward J.

1989-01-01

390

Ultralow thermal conductivity of nanoparticle packed bed  

NASA Astrophysics Data System (ADS)

We show that thermal conductivity of packed bed of alumina nanoparticles can be as low as 0.035 W/m K which is only 35% higher than the thermal conductivity of air and is smaller than the recently reported lowest thermal conductivity of solids using disordered layered WeS2. These findings show a promising approach for making low-cost and ultralow thermal conductivity thermal insulation materials with high density and good sustainability at high pressures.

Hu, X. Jack; Prasher, Ravi; Lofgreen, Kelly

2007-11-01

391

PackBot EOD firing system  

NASA Astrophysics Data System (ADS)

The PackBot EOD firing system was developed to allow the safe initiation of disruptors used to disable improvised explosive devices (IEDs). Safety is assured despite the use of communication links shared by possibly insecure computers on UGVs and control stations. This specific firing system was developed to enforce a particular EOD operational protocol where a single operator is responsible for the loading and use of the weapon. A unique combination of hardware and software design allows for unprecedented safety.

Rudakevych, Pavlo; Ciholas, Mike

2005-05-01

392

Frac packs complicate PNC log evaluation  

SciTech Connect

Borate-crosslinked fluids and/or ceramic proppants commonly included in frac-pack well completions can compliance pulsed neutron capture (PNC) log evaluation. PNC logs are routinely run in cased holes. Two common applications include identifying formation fluid and calculating the percent water saturation in the rock pore spaces near the well bore. The paper discusses PNC logs, a case history of a West Delta oil well, laboratory work, and results. Recommendations are given.

Bean, C.L.; Ali, S.A. [Chevron U.S.A. Production Co., New Orleans, LA (United States); Salaita, G.N. [Chevron Petroleum Technology Co., Houston, TX (United States)

1996-12-23

393

Hydraulic jet pumping in a remote location  

SciTech Connect

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.

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

1986-12-01

394

Chain Packing and Trajectory of Isotactic Polypropylene ? Crystals studied by Solid-State NMR  

NASA Astrophysics Data System (ADS)

Isotactic polypropylene (ipp) is one of the simplest polyolefins and the crystalline structures, have been extensively studied. Ipp crystallizes as ? form via isothermal crystallization from the melt state. Packing structures of ? form has been used as structural markers of crystallization process. With the development of high resolution solid-state NMR (SS-NMR) technique, it becomes a powerful tool to investigate order-disorder of chain packing in the crystalline regions. We performed a series of experiments on different samples crystallized at different temperatures and studied the formation of ? crystals influenced by different parameters, such as molecular weight, catalyst type and stereo, region regularity. Using selectively ^13C enriched ipp samples we detect inter-nuclear correlations between the neighboring stems. This information provides chain reentry information. We figure out relationship between the chain reentry and chain packing of ipp ? crystals. The recent discovery of the ipp ?2 single crystal offers a great opportunity to understand this topic also.

Li, Zhen; Cao, Yan; Miyoshi, Toshikazu; Cheng, Stephen

2012-02-01

395

Evolution of the force distributions in jammed packings of soft particles  

NASA Astrophysics Data System (ADS)

The evolution of the force distributions during the isotropic compression of two-dimensional packings of soft frictional particles is investigated numerically. Regardless of the applied deformation, the normal contact force distribution P (fn) can be fitted by the product of a power law, and a stretched exponential, while the tangential force distribution P (ft) is fitted well by a Gaussian. With increasing strain, the asymptotic behavior at large forces does not change, but both P (fn) and P (ft) exhibit a broadening, even though, when scaled with the average forces, their widths decrease. Furthermore, the distribution of friction mobilization P (?) is a decreasing function of ? =|ft|/(?fn), except for an increased probability of fully mobilized contacts (? =1). The excess coordination number of the packings increases with the applied strain, indicating that the more a packing is compressed the more stable it becomes.

Boberski, Jens; Shaebani, M. Reza; Wolf, Dietrich E.

2013-12-01

396

Effect of metal powder packing on the conductivity of nanometal ink.  

PubMed

The power of nanotechnology is realized in its application in numerous areas. One such area is undoubtedly the use of metallic nanoparticles as a direct write application. An effort in this area has resulted in a conductive ink whose conductivity approaches 60-70% that of the bulk copper. Such an ink has been developed by reducing silver, gold, and copper nano-sized powders by a wet method and followed by a heat treatment at less than 400 degrees C. The conductivity of the resulting ink product was found to be very much affected by how various sizes of metal powders are packed when particles were dried and packed on various substrates. The effect of packing and various kinds of metal powders on the eventual conductivity of the final product of the ink has been described and discussed in this paper. PMID:18047084

Kim, Nam-Soo; Amert, Anthony K; Woessner, Stephen M; Decker, Shawn; Kang, Sun-Mee; Han, Kenneth N

2007-11-01

397

The Performance of Structured Packings in Trickle-Bed Reactors  

Microsoft Academic Search

An experimental study was carried out to investigate whether the use of structured packings might improve the mass transfer characteristics and the catalyst effectiveness of a trickle-bed reactor. Therefore, the performances of a structured packing, consisting of KATAPAK elements, and a dumped packing, consisting of small diameter spherical particles, have been compared for both a chemisorption process and a process

M. J. W. Frank; J. A. M. Kuipers; G. F. Versteeg; W. P. M. Van swaaij

1999-01-01

398

48 CFR 452.247-72 - Packing for Domestic Shipment.  

Code of Federal Regulations, 2013 CFR

...2013-10-01 2013-10-01 false Packing for Domestic Shipment. 452.247-72...Provisions and Clauses 452.247-72 Packing for Domestic Shipment. As prescribed...b), insert the following clause: Packing for Domestic Shipment (FEB...

2013-10-01

399

48 CFR 552.211-87 - Export packing.  

Code of Federal Regulations, 2013 CFR

...2013-10-01 2013-10-01 false Export packing. 552.211-87 Section 552.211-87...and Clauses 552.211-87 Export packing. As prescribed in 511.204(b)(7), insert the following clause: Export Packing (JAN 2010) (a) Offerors...

2013-10-01

400

1. Contextual view looking west, showing packing house and Union ...  

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

1. Contextual view looking west, showing packing house and Union Ice building, which is located to the north of Packing House (right hand side in photo) - College Heights Lemon Packing House, 519-532 West First Street, Claremont, Los Angeles County, CA

401

29 CFR 784.135 - âPacking  

Code of Federal Regulations, 2013 CFR

...Relating to Fishing and Aquatic Products First Processing, Canning, Or Packing of Marine Products Under Section 13(a)(5) § 784.135 âPacking.â The packing of the various named marine products at sea as an incident to, or...

2013-07-01

402

48 CFR 852.214-73 - Alternate packaging and packing.  

Code of Federal Regulations, 2013 CFR

...2013-10-01 false Alternate packaging and packing. 852.214-73 Section 852.214-73...852.214-73 Alternate packaging and packing. As prescribed in 814.201-6...provision: Alternate Packaging and Packing (JAN 2008) The bidder's...

2013-10-01

403

48 CFR 452.247-73 - Packing for Overseas Shipment.  

Code of Federal Regulations, 2013 CFR

...2013-10-01 2013-10-01 false Packing for Overseas Shipment. 452.247-73...Provisions and Clauses 452.247-73 Packing for Overseas Shipment. As prescribed...c), insert the following clause: Packing for Overseas Shipment (FEB...

2013-10-01

404

29 CFR 784.135 - âPacking  

Code of Federal Regulations, 2010 CFR

...Relating to Fishing and Aquatic Products First Processing, Canning, Or Packing of Marine Products Under Section 13(a)(5) § 784.135 âPacking.â The packing of the various named marine products at sea as an incident to, or...

2009-07-01

405

46 CFR 160.043-6 - Marking and packing.  

Code of Federal Regulations, 2013 CFR

... 2013-10-01 false Marking and packing. 160.043-6 Section 160.043-6...Vessels § 160.043-6 Marking and packing. (a) General. Jackknives...method for using the can opener. (c) Packing. Each jackknife, complete...

2013-10-01

406

48 CFR 552.211-77 - Packing List.  

Code of Federal Regulations, 2013 CFR

...2013-10-01 2013-10-01 false Packing List. 552.211-77 Section...Provisions and Clauses 552.211-77 Packing List. As prescribed in 511.204(c), insert the following clause: Packing List (FEB 1996) (a) A...

2013-10-01

407

Mechanistic pressure drop model for columns containing structured packings  

Microsoft Academic Search

A mechanistic model was developed to predict pressure drop and flooding in packed columns equipped with corrugated packing of the regular type. It was developed after considering the interaction of falling liquid film with the gas phase, based on mass- and momentum-conservation equations. Among the most common structured packings, the behavior of the Mellapak and BX types was analyzed. The

E. Brunazzi; Alessandro Paglianti

1997-01-01

408

Force transmission in a packing of pentagonal particles  

Microsoft Academic Search

We perform a detailed analysis of the contact force network in a dense confined packing of pen- tagonal particles simulated by means of the contact dynamics method. The effect of particle shape is evidenced by comparing the data from pentagon packing and from a packing with identical char- acteristics except for the circular shape of the particles. A counterintuitive finding

Emilien Azema; Farhang Radja; Robert Peyroux; Gilles Saussine

2007-01-01

409

Force transmission in a packing of pentagonal particles  

Microsoft Academic Search

We perform a detailed analysis of the contact force network in a dense confined packing of pentagonal particles simulated by means of the contact dynamics method. The effect of particle shape is evidenced by comparing the data from pentagon packing and from a packing with identical characteristics, except for the circular shape of the particles. A counterintuitive finding of this

Emilien Azéma; Farhang Radjaï; Robert Peyroux; Gilles Saussine

2007-01-01

410

Influence of fiber packing structure on permeability  

NASA Technical Reports Server (NTRS)

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.

Cai, Zhong; Berdichevsky, Alexander L.

1993-01-01

411

Probe with integrated heater and thermocouple pack  

DOEpatents

A probe for measuring heat includes an elongate rod fitted within a sheath, and a plurality of annular recesses are formed on the surface of the rod in a spaced-apart relationship to form annular chambers that are resistant to heat flow. A longitudinal bore extends axially into the rod and within the cylinders defined by the annular chambers, and an integrated heater and thermocouple pack is dimensioned to fit within the bore. In construction, the integrated pack includes a plurality of wires disposed in electrical insulation within a sheath and a heater cable. These wires include one common wire and a plurality of thermocuple wires. The common wire is constructed of one type of conductive material while the thermocouple wires are each constructed of two types of materials so that at least one thermocouple junction is formed therein. All of the wires extend the length of the integrated pack and are connected together at their ends. The thermocouple wires are constructed to form thermocouple junctions proximate to each annular chamber for producing electromotive forces corresponding to the temperature of the rod within the annular chambers relative to outside the chambers. In the preferred embodiment, each thermocouple wire forms two thermocouple junctions, one junction being disposed within an annular chamber and the second junction being disposed outside of, but proximate to, the same annular chamber. In one embodiment two thermocouple wires are configured to double the sensitivity of the probe in one region.

McCulloch, Reg W. (Oak Ridge, TN); Dial, Ralph E. (Concord, TN); Finnell, Wilber K. R. (Kingston, TN)

1990-01-01

412

Electrolytic hydrogen production at packed bed electrode  

NASA Astrophysics Data System (ADS)

Results are presented of the experimental production of electrolytic hydrogen at a packed bed electrode. Electrolysis was carried out in a two-compartment cell with a packed bed of spherical copper, nickel, pyrite, silver-coated glass or carbon-coated glass particles as the cathode and a platinum spiral anode in solutions of 5, 10, 20 and 30 wt % KOH and 20 wt % NaOH, KCl, H2SO4 and HCl. Measurements of the open-circuit potential and overpotential reveal only the bed of copper spheres to have an overpotential less than that of the platinum cathodic feeder. A lower overpotential was obtained in the KOH solutions, with a minimum at a concentration of 20 wt %. Particle volume as well as surface area are also observed to influence the overpotentials recorded, while electrolyte flow is found to increase the electrode potential for hydrogen reduction and increases in temperature decrease the potential. Results obtained thus demonstrate the feasibility of applying packed bed electrodes for electrolytic hydrogen production.

Stankovic, Z. D.

413

Probe with integrated heater and thermocouple pack  

DOEpatents

A probe for measuring heat includes an elongate rod fitted within a sheath, and a plurality of annular recesses are formed on the surface of the rod in a spaced-apart relationship to form annular chambers that are resistant to heat flow. A longitudinal bore extends axially into the rod and within the cylinders defined by the annular chambers, and an integrated heater and thermocouple pack is dimensioned to fit within the bore. In construction, the integrated pack includes a plurality of wires disposed in electrical insulation within a sheath and a heater cable. These wires include one common wire and a plurality of thermocouple wires. The common wire is constructed of one type of conductive material while the thermocouple wires are each constructed of two types of materials so that at least one thermocouple junction is formed therein. All of the wires extend the length of the integrated pack and are connected together at their ends. The thermocouple wires are constructed to form thermocouple junctions proximate to each annular chamber for producing electromotive forces corresponding to the temperature of the rod within the annular chambers relative to outside the chambers. In the preferred embodiment, each thermocouple wire forms two thermocouple junctions, one junction being disposed within an annular chamber and the second junction being disposed outside of, but proximate to, the same annular chamber. In one embodiment two thermocouple wires are configured to double the sensitivity of the probe in one region.

McCulloch, Reginald W. (Oak Ridge, TN); Dial, Ralph E. (Concord, TN); Finnell, Wilber K. R. (Kingston, TN)

1988-01-01

414

Removing freon gas from hydraulic fluid  

NASA Technical Reports Server (NTRS)

Dissolved freon gas is removed from hydraulic fluid by raising temperature to 150 F and bubbling dry nitrogen gas through it, even while fluid circulates through hydraulic system. Procedure reduces parts corrosion, sludge formation, and contamination.

Williams, B. B.; Mitchell, S. M.; State, T. S.

1981-01-01

415

Machine Construction Hydraulics: A Reference Manual.  

National Technical Information Service (NTIS)

The report presents the basic principles of the hydraulics of pipelines, the flow of fluid through capillary slits, and the theory of hydraulic impact in hydrosystems. The author examines the principles of the theory, design and calculation of pumps, hydr...

T. M. Bashta

1973-01-01

416

CRITICALITY CURVES FOR PLUTONIUM HYDRAULIC FLUID MIXTURES  

SciTech Connect

This Calculation Note performs and documents MCNP criticality calculations for plutonium (100% {sup 239}Pu) hydraulic fluid mixtures. Spherical geometry was used for these generalized criticality safety calculations and three geometries of neutron reflection are: {sm_bullet}bare, {sm_bullet}1 inch of hydraulic fluid, or {sm_bullet}12 inches of hydraulic fluid. This document shows the critical volume and critical mass for various concentrations of plutonium in hydraulic fluid. Between 1 and 2 gallons of hydraulic fluid were discovered in the bottom of HA-23S. This HA-23S hydraulic fluid was reported by engineering to be Fyrquel 220. The hydraulic fluid in GLovebox HA-23S is Fyrquel 220 which contains phosphorus. Critical spherical geometry in air is calculated with 0 in., 1 in., or 12 inches hydraulic fluid reflection.

WITTEKIND WD

2007-10-03

417

46 CFR 28.880 - Hydraulic equipment.  

Code of Federal Regulations, 2013 CFR

...COAST GUARD, DEPARTMENT OF HOMELAND SECURITY UNINSPECTED VESSELS REQUIREMENTS FOR COMMERCIAL FISHING INDUSTRY VESSELS Aleutian Trade Act Vessels § 28.880 Hydraulic equipment. (a) Each hydraulic system must be so designed and installed...

2013-10-01

418

Hydraulic Roughness of Segmentally Lined Tunnels.  

National Technical Information Service (NTIS)

Factors affecting the hydraulic performance of segmentally lined tunnels have been investigated. Fifteen tunnels were surveyed to provide data on tunnel geometry covering the four main types of tunnel lining segment used in the UK. Hydraulic tests were un...

J. D. Pitt P. Ackers

1982-01-01

419

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

NASA Astrophysics Data System (ADS)

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.

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

2011-12-01

420

The hydraulic limitation hypothesis revisited  

Microsoft Academic Search

We proposed the hydraulic limitation hypothesis (HLH) as a mechanism to explain universal patterns in tree height, and tree and stand biomass growth: height growth slows down as trees grow taller, maximum height is lower for trees of the same species on resource-poor sites and annual wood production declines after canopy closure for even-aged for- ests. Our review of 51

MICHAEL G. RYAN; NATHAN PHILLIPS; BARBARA J. BOND

2006-01-01

421

Tree Hydraulics: How Sap Rises  

ERIC Educational Resources Information Center

Trees transport water from roots to crown--a height that can exceed 100 m. The physics of tree hydraulics can be conveyed with simple fluid dynamics based upon the Hagen-Poiseuille equation and Murray's law. Here the conduit structure is modelled as conical pipes and as branching pipes. The force required to lift sap is generated mostly by…

Denny, Mark

2012-01-01

422

Analysis of Hydraulic Conductivity Calculations.  

National Technical Information Service (NTIS)

Equations by Marshall and by Millington and Quirk for calculating hydraulic conductivity from pore-size distribution data are dependent on an arbitrary choice of the exponent on the porosity term and a correct estimate of residual water. This study showed...

R. E. Green J. C. Corey

1969-01-01

423

Introduction to Hydraulics. Instructor's Guide.  

ERIC Educational Resources Information 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…

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

424

Introduction to Hydraulics. Student's Manual.  

ERIC Educational Resources Information 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…

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

425

Silent Variable Delivery Hydraulic Pump.  

National Technical Information Service (NTIS)

The hydraulic pump is used on a submarine. The apparatus includes a valve device in the form of a plate and a multi-cylinder, parallel piston pump. The pump includes a rotatable assembly comprised of a barrel body with a plurality of parallel cylinders, e...

A. Lehrer

1965-01-01

426

Thermal-Hydraulic-Analysis Program  

NASA Technical Reports Server (NTRS)

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.

Walton, J. T.

1993-01-01

427

Hydraulic geometry of river cross sections; theory of minimum variance  

USGS Publications Warehouse

This study deals with the rates at which mean velocity, mean depth, and water-surface width increase with water discharge at a cross section on an alluvial stream. Such relations often follow power laws, the exponents in which are called hydraulic exponents. The Langbein (1964) minimum-variance theory is examined in regard to its validity and its ability to predict observed hydraulic exponents. The variables used with the theory were velocity, depth, width, bed shear stress, friction factor, slope (energy gradient), and stream power. Slope is often constant, in which case only velocity, depth, width, shear and friction factor need be considered. The theory was tested against a wide range of field data from various geographic areas of the United States. The original theory was intended to produce only the average hydraulic exponents for a group of cross sections in a similar type of geologic or hydraulic environment. The theory does predict these average exponents with a reasonable degree of accuracy. An attempt to forecast the exponents at any selected cross section was moderately successful. Empirical equations are more accurate than the minimum variance, Gauckler-Manning, or Chezy methods. Predictions of the exponent of width are most reliable, the exponent of depth fair, and the exponent of mean velocity poor. (Woodard-USGS)

Williams, Garnett P.

1978-01-01

428

Climbing robot actuated by meso-hydraulic artificial muscles  

NASA Astrophysics Data System (ADS)

This paper presents the design, construction, experimental characterization, and system testing of a legged, wall-climbing robot actuated by meso-scale hydraulic artificial muscles. While small wall-climbing robots have seen increased research attention in recent years, most authors have primarily focused on designs for the gripping and adhesion of the robot to the wall, while using only standard DC servo-motors for actuation. This project seeks to explore and demonstrate a different actuation mechanism that utilizes hydraulic artificial muscles. A four-limb climbing robot platform that includes a full closed-loop hydraulic power and control system, custom hydraulic artificial muscles for actuation, an on-board microcontroller and RF receiver for control, and compliant claws with integrated sensing for gripping a variety of wall surfaces has been constructed and is currently being tested to investigate this actuation method. On-board power consumption data-logging during climbing operation, analysis of the robot kinematics and climbing behavior, and artificial muscle force-displacement characterization are presented to investigate and this actuation method.

Bryant, Matthew; Fitzgerald, Jason; Miller, Samuel; Saltzman, Jonah; Kim, Sangkyu; Lin, Yong; Garcia, Ephrahim

2014-03-01

429

Assessing plant hydraulic architecture with ultrasonic acoustic emission techniques  

NASA Astrophysics Data System (ADS)

Water is transported through the xylem of plants under tension (negative pressure). If the tension within a xylem conduit exceeds a critical value, cavitation can occur, which if followed by embolism leads to blockage of water transport through the conduit. Plant species and different organs within the plant such as roots, stems and leaves vary widely in the xylem tension thresholds at which cavitation events begin to occur. Massive cavitation and embolism can lead to catastrophic hydraulic failure and plant death from dehydration. Ultrasonic acoustic emission (UAE) transducers provide a non-invasive means of detecting cavitation events in plants and recording the accumulation of these events through time. When used in combination with other techniques, recording of UAEs can be a powerful tool for characterizing and understanding plant hydraulic architecture; the collection of properties that determine the efficiency and vulnerability of water transport from roots to leaves. The hydraulic architecture of leaves is particularly complex because water must traverse the dead cells of the xylem plus an extra-xylary pathway consisting of living cells and intercellular spaces before it arrives at the internal evaporating surfaces. We used UAE, imaging and other techniques to determine the extent to which dehydration-induced declines in leaf hydraulic conductance were associated with xylem cavitation and embolism versus changes in the conductance of the extra-xylary pathway. In most of the evergreen and deciduous tree species studied there was a close correspondence between the trajectories of cumulative UAEs and loss of whole-leaf hydraulic conductance during dehydration. The mean amplitude of UAEs was positively correlated with mean conduit diameter indicating that in addition to detecting cavitation events, analysis of UAE features can provide information about relative changes in xylem hydraulic conductivity because conductivity is a function of conduit radius to the fourth power. We were unable to detect UAEs from conduits smaller than about 4 micrometers in diameter. The occurrence of embolism in leaf xylem was confirmed independently with cryo-SEM and light microscopy imaging. As expected, there was considerable variation among species in the leaf water potential thresholds at which xylem cavitation and loss of hydraulic conductance began to occur. Contrary to suggestions from some published studies, we saw no evidence of reversible partial xylem conduit collapse instead of cavitation during dehydration. Results from our field studies indicate that dehydration-induced embolism in leaf xylem is completely reversible over a 24-hour cycle, but the mechanism for refilling xylem conduits is unknown. We discuss constraints on the application of UAE techniques for studying plant hydraulics.

Meinzer, F. C.; Johnson, D.; McCulloh, K.; Woodruff, D.

2012-12-01

430

23 CFR 650.111 - Location hydraulic studies.  

Code of Federal Regulations, 2010 CFR

... 2009-04-01 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...

2009-04-01

431

23 CFR 650.111 - Location hydraulic studies.  

Code of Federal Regulations, 2010 CFR

... 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...

2010-04-01

432

Hydraulic Circuit for Prevention of Inadvertent Weapon Launches.  

National Technical Information Service (NTIS)

A hydraulic circuit for prevention of inadvertent weapons launches in which a hydraulic firing valve provides hydraulic pressure to a backup select valve rather than the backup select valve receiving hydraulic pressure directly from a ship supply header. ...

M. T. Ansay

2006-01-01

433

Motor applications for hydraulic roll crushers  

Microsoft Academic Search

The hydraulic roll crusher (HRC) is a relative newcomer to the family of major cement producing machinery, which includes kilns, mills, and the like. Also, there are a variety of configurations in which the hydraulic roll crusher may be utilized. These two factors, among others, may sometimes make the proper selection and specification of drive motors for the hydraulic roll

G. R. Kotz; M. P. Regan

1994-01-01

434

Strong interlocking of nonconvex particles in random packings  

NASA Astrophysics Data System (ADS)

We present a numerical study of random packings made of nonconvex grains. These particles are built by the agglomeration of overlapping spheres in order to control their sphericity ?. The contact number C is found to be much larger than the coordination number Z, providing a significant difference with convex grains. The packing properties are found to be highly dependent on the morphological parameters of the grains : packing fractions as low as 0.3 have been reached. More importantly, the way nonconvex grains develop multiple contacts, i.e., interlocking, is found to be a relevant effect in such packings. Interlocking provides more stability to loose packings.

Ludewig, F.; Vandewalle, N.

2012-05-01

435

Using Stream Leaf Packs to Explore Community Assembly  

NSDL National Science Digital Library

In this TIEE experiment, students will explore functional and taxonomic diversity in a stream ecosystem, learn about food web relationships, and learn about the ways in which abiotic and biotic factors determine what organisms are present in a community. Students will make and install artificial leaf packs in a stream, wait for the leaf packs to be colonized by stream organisms, measure abiotic variables that could influence leaf pack colonization, retrieve the leaf packs and classify the organisms they find in both taxonomic and functional ways, and participate in a class discussion of how the leaf pack community is situated within a larger ecosystem.

Hartley, Laurel

2011-08-29

436

Vertical fracture containment during massive hydraulic fracturing  

SciTech Connect

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.

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

1983-01-01

437

Thermal hydraulic analysis of advanced Pb-Bi cooled NPP using natural circulation  

NASA Astrophysics Data System (ADS)

We present thermal hydraulic analysis for a low power advanced nuclear reactor cooled by lead-bismuth eutectic. In this work is to study the thermal hydraulic analysis of a low power SPINNOR (Small Power Reactor, Indonesia, No On-site Refuelling) reactor with 125 MWth which a design a core with very small volume and fuel column height, resulting in a negative coolant temperature coefficient and very low channel pressure drop. And also at full power the heat can be completely removed by natural circulation in the primary circuit, thus eliminating the needs for pumps.

Novitrian; Su'ud, Zaki; Waris, Abdul

2012-06-01

438

Non-Euclidean geometry of twisted filament bundle packing  

PubMed Central

Densely packed and twisted assemblies of filaments are crucial structural motifs in macroscopic materials (cables, ropes, and textiles) as well as synthetic and biological nanomaterials (fibrous proteins). We study the unique and nontrivial packing geometry of this universal material design from two perspectives. First, we show that the problem of twisted bundle packing can be mapped exactly onto the problem of disc packing on a curved surface, the geometry of which has a positive, spherical curvature close to the center of rotation and approaches the intrinsically flat geometry of a cylinder far from the bundle center. From this mapping, we find the packing of any twisted bundle is geometrically frustrated, as it makes the sixfold geometry of filament close packing impossible at the core of the fiber. This geometrical equivalence leads to a spectrum of close-packed fiber geometries, whose low symmetry (five-, four-, three-, and twofold) reflect non-Euclidean packing constraints at the bundle core. Second, we explore the ground-state structure of twisted filament assemblies formed under the influence of adhesive interactions by a computational model. Here, we find that the underlying non-Euclidean geometry of twisted fiber packing disrupts the regular lattice packing of filaments above a critical radius, proportional to the helical pitch. Above this critical radius, the ground-state packing includes the presence of between one and six excess fivefold disclinations in the cross-sectional order.

Bruss, Isaac R.; Grason, Gregory M.

2012-01-01

439

Strain Stiffening in Random Packings of Entangled Granular Chains  

NASA Astrophysics Data System (ADS)

Random packings of granular chains are presented as a model system to investigate the contribution of entanglements to strain stiffening. The chain packings are sheared in uniaxial compression experiments. For short chain lengths, these packings yield when the shear stress exceeds the scale of the confining pressure, similar to granular packings of unconnected particles. In contrast, packings of chains which are long enough to form loops exhibit strain stiffening, in which the effective stiffness of the material increases with strain, similar to many polymer materials. The latter packings can sustain stresses orders-of-magnitude greater than the confining pressure, and do not yield until the chain links break. X-ray tomography measurements reveal that the strain-stiffening packings contain system-spanning clusters of entangled chains.

Brown, Eric; Nasto, Alice; Athanassiadis, Athanasios G.; Jaeger, Heinrich M.

2012-03-01

440

Design of hydraulic output Stirling engine  

NASA Technical Reports Server (NTRS)

A hydraulic output system for the RE-1000 free piston stirling engine (FPSE) was designed. The hydraulic output system can be readily integrated with the existing hot section of RE-1000 FPSE. The system has two simply supported diaphragms which separate the engine gas from the hydraulic fluid, a dynamic balance mechanism, and a novel, null center band hydraulic pump. The diaphragms are designed to endure more than 10 billion cycles, and to withstand the differential pressure load as high as 14 MPa. The projected thermodynamic performance of the hydraulic output version of RE-1000 FPSE is 1.87 kW at 29/7 percent brake efficiency.

Toscano, W. M.; Harvey, A. C.; Lee, K.

1983-01-01

441

Mapping the distribution of packing topologies within protein interiors shows predominant preference for specific packing motifs  

PubMed Central

Background Mapping protein primary sequences to their three dimensional folds referred to as the 'second genetic code' remains an unsolved scientific problem. A crucial part of the problem concerns the geometrical specificity in side chain association leading to densely packed protein cores, a hallmark of correctly folded native structures. Thus, any model of packing within proteins should constitute an indispensable component of protein folding and design. Results In this study an attempt has been made to find, characterize and classify recurring patterns in the packing of side chain atoms within a protein which sustains its native fold. The interaction of side chain atoms within the protein core has been represented as a contact network based on the surface complementarity and overlap between associating side chain surfaces. Some network topologies definitely appear to be preferred and they have been termed 'packing motifs', analogous to super secondary structures in proteins. Study of the distribution of these motifs reveals the ubiquitous presence of typical smaller graphs, which appear to get linked or coalesce to give larger graphs, reminiscent of the nucleation-condensation model in protein folding. One such frequently occurring motif, also envisaged as the unit of clustering, the three residue clique was invariably found in regions of dense packing. Finally, topological measures based on surface contact networks appeared to be effective in discriminating sequences native to a specific fold amongst a set of decoys. Conclusions Out of innumerable topological possibilities, only a finite number of specific packing motifs are actually realized in proteins. This small number of motifs could serve as a basis set in the construction of larger networks. Of these, the triplet clique exhibits distinct preference both in terms of composition and geometry.

2011-01-01

442

49 CFR 173.145 - Other Regulated Materials-Assignment of packing group.  

Code of Federal Regulations, 2013 CFR

...Other Regulated Materials-Assignment of packing group. 173.145 Section 173.145...PACKAGINGS Definitions Classification, Packing Group Assignments and Exceptions for...Other Regulated MaterialsâAssignment of packing group. Packing groups are not...

2013-10-01

443

Jamming in frictionless packings of spheres: determination of the critical volume fraction  

NASA Astrophysics Data System (ADS)

The jamming transition in granular packings is characterized by a sudden change in the coordination number. In this work we investigate the evolution of coordination number as function of volume fraction for frictionless packings of spheres undergoing isotropic deformation. Using the results obtained from Discrete Element Method simulations, we confirm that the coordination number depends on volume fraction by a power law with exponent ?~0.5 above the critical volume fraction and up to rather high densities. We find that the system size and loading rate do not have an important effect on the evolution of the coordination number. Polydispersity of the packing seems to cause a shift in the critical volume fraction, i.e., more heterogeneous packings jam at higher volume fractions. Finally, we propose and evaluate alternative methods to determine the critical volume fraction based on the number of rattlers, the pressure and the ratio of kinetic and potential energies. The results are all consistent with the critical volume fractions obtained from the fits of the power law to the simulation data.

Göncü, F.; Durán, O.; Luding, S.

2009-06-01

444

Optimised Iteration in Coupled Monte Carlo - Thermal-Hydraulics Calculations  

NASA Astrophysics Data System (ADS)

This paper describes an optimised iteration scheme for the number of neutron histories and the relaxation factor in successive iterations of coupled Monte Carlo and thermal-hydraulic reactor calculations based on the stochastic iteration method. The scheme results in an increasing number of neutron histories for the Monte Carlo calculation in successive iteration steps and a decreasing relaxation factor for the spatial power distribution to be used as input to the thermal-hydraulics calculation. The theoretical basis is discussed in detail and practical consequences of the scheme are shown, among which a nearly linear increase per iteration of the number of cycles in the Monte Carlo calculation. The scheme is demonstrated for a full PWR type fuel assembly. Results are shown for the axial power distribution during several iteration steps. A few alternative iteration method are also tested and it is concluded that the presented iteration method is near optimal.

Hoogenboom, J. Eduard; Dufek, Jan

2014-06-01

445

Techdrill`s Drill Soft Pack One  

SciTech Connect

This article presents the main features of Drill Soft Pack One (DSP-One) version 1.4 developed by Techdrill (Paris, France). DSP-One is an integrated drilling engineering package that covers most aspects of drilling engineering. The package has been used for 6 months to prepare drilling programs and monitor wells. DSP-One is a PC-based, fully menu-driven program that runs on any IBM PC compatible. The program requires 550 KB of memory and 6 MB of hard-disk space. The software manufacture recommends a math coprocessor for speed and a VGA color monitor to achieve full benefit from the color graphic displays.

Prieur, J.M. [Conoco Ltd. (United Kingdom)

1993-12-01

446

Packed fluidized bed blanket for fusion reactor  

DOEpatents

A packed fluidized bed blanket for a fusion reactor providing for efficient radiation absorption for energy recovery, efficient neutron absorption for nuclear transformations, ease of blanket removal, processing and replacement, and on-line fueling/refueling. The blanket of the reactor contains a bed of stationary particles during reactor operation, cooled by a radial flow of coolant. During fueling/refueling, an axial flow is introduced into the bed in stages at various axial locations to fluidize the bed. When desired, the fluidization flow can be used to remove particles from the blanket.

Chi, John W. H. (Mt. Lebanon, PA)

1984-01-01

447

Packing C60 in Boron Nitride Nanotubes  

NASA Astrophysics Data System (ADS)

We have created insulated C60 nanowire by packing C60 molecules into the interior of insulating boron nitride nanotubes (BNNTs). For small-diameter BNNTs, the wire consists of a linear chain of C60 molecules. With increasing BNNT inner diameter, unusual C60 stacking configurations are obtained (including helical, hollow core, and incommensurate) that are unknown for bulk or thin-film forms of C60. C60 in BNNTs thus presents a model system for studying the properties of dimensionally constrained ``silo'' crystal structures. For the linear-chain case, we have fused the C60 molecules to form a single-walled carbon nanotube inside the insulating BNNT.

Mickelson, W.; Aloni, S.; Han, Wei-Qiang; Cumings, John; Zettl, A.

2003-04-01

448

Characterization of a new 4.5 kV press pack SPT+ IGBT in Voltage Source Converters with clamp circuit  

Microsoft Academic Search

Recently developed IGBT press pack devices have become a competition for IGCTs in high power industrial applications. This paper presents an overview of state-of-the-art medium voltage power semiconductors with active turn-off capability. A new 85 mm, 4.5 kV, 1.2 kA press pack SPT+ IGBT and the corresponding freewheeling diode are characterized for an operation in Voltage Source Converters. To reduce

Rodrigo Alvarez; Steffen Bernet; Lars Lindenmueller; Felipe Filsecker

2010-01-01

449

Thermal hydraulics development for CASL  

Microsoft Academic Search

This talk will describe the technical direction of the Thermal-Hydraulics (T-H) Project within the Consortium for Advanced Simulation of Light Water Reactors (CASL) Department of Energy Innovation Hub. CASL is focused on developing a 'virtual reactor', that will simulate the physical processes that occur within a light-water reactor. These simulations will address several challenge problems, defined by laboratory, university, and

Lowrie; Robert B

2010-01-01

450

The application of hydraulics in the 2,000 kW wind turbine generator  

NASA Technical Reports Server (NTRS)

A 2000 kW turbine generator using hydraulic power in two of its control systems is being built under the management of NASA Lewis Research Center. The hydraulic systems providing the control torques and forces for the yaw and blade pitch control systems are discussed. The yaw-drive-system hydraulic supply provides the power for positioning the nacelle so that the rotary axis is kept in line with the direction of the prevailing wind, as well as pressure to the yaw and high speed shaft brakes. The pitch-change-mechanism hydraulic system provides the actuation to the pitch change mechanism and permits feathering of the blades during an emergency situation. It operates in conjunction with the overall windmill computer system, with the feather control permitting slewing control flow to pass from the servo valve to the actuators without restriction.

Onufreiczuk, S.

1978-01-01

451

Effect of a hydraulic jet prophylaxis system on composites.  

PubMed

Because air-powered devices that remove surface stain from teeth are commercially available, recent literature concerning the effect of the hydraulic jet prophylaxis system on oral tissues and restorative materials was reviewed. A study designed to compare the volume loss by different types of composites abraded by this system revealed a relatively high rate of abrasion for the small-particle composite compared with composites containing larger filler particles. PMID:2542536

Reel, D C; Abrams, H; Gardner, S L; Mitchell, R J

1989-04-01

452

Hydraulic blowdown TVA system for the Castor 120 motor program  

NASA Astrophysics Data System (ADS)

The performance and reliability of a low-cost hydraulic blowdown system for expendable launch vehicles (ELVs) are demonstrated in the context of the Castro 120 motor program. Test results are reported which show that the blowdown system meets or exceeds the performance objectives for an ELV motor in a Stage I, Stage II, or strap-on application. The primary cost savings include replacement of the expensive turbine pump and auxiliary power source and the use of a simplified actuator design.

Lee, R. G.; Olsen, G. E.; Trowbridge, C. G.; Griffis, D. M.

1993-06-01

453

Hydraulic characteristics and structure of porous metal fiber materials  

Microsoft Academic Search

1.The hydraulic properties of permeable fiber materials, like those of powder materials, can be evaluated using only one parameter, namely, the gas-permeability coefficient.2.The relationship between the gas permeability and porosity of fiber materials is described by a power equation the exponent of which increases from 2.5–4.0 to 5.0 as the fiber diameter is decreased from 200 to 50µ.3.Increasing the porosity

A. G. Kostornov; M. S. Shevchuk

1973-01-01

454

Investigation of hydraulic transmission noise sources  

NASA Astrophysics Data System (ADS)

Advanced hydrostatic transmissions and hydraulic hybrids show potential in new market segments such as commercial vehicles and passenger cars. Such new applications regard low noise generation as a high priority, thus, demanding new quiet hydrostatic transmission designs. In this thesis, the aim is to investigate noise sources of hydrostatic transmissions to discover strategies for designing compact and quiet solutions. A model has been developed to capture the interaction of a pump and motor working in a hydrostatic transmission and to predict overall noise sources. This model allows a designer to compare noise sources for various configurations and to design compact and inherently quiet solutions. The model describes dynamics of the system by coupling lumped parameter pump and motor models with a one-dimensional unsteady compressible transmission line model. The model has been verified with dynamic pressure measurements in the line over a wide operating range for several system structures. Simulation studies were performed illustrating sensitivities of several design variables and the potential of the model to design transmissions with minimal noise sources. A semi-anechoic chamber has been designed and constructed suitable for sound intensity measurements that can be used to derive sound power. Measurements proved the potential to reduce audible noise by predicting and reducing both noise sources. Sound power measurements were conducted on a series hybrid transmission test bench to validate the model and compare predicted noise sources with sound power.

Klop, Richard J.

455

Support for transmission shaft and hydraulic servo drum  

SciTech Connect

In a support for use in an automatic transmission apparatus of the type having a transmission shaft for transmitting power, an annular hydraulic servo drum and a piston fitted in the hydraulic servo drum for engaging and disengaging a friction engaging means is described, wherein the support has an axially extending tubular supporting portion having an inner peripheral surface for supporting the transmission shaft, an outer peripheral surface for supporting an inner cylindrical portion of the hydraulic servo drum, and working oil passages formed and adapted for supplying and discharging a working oil to and from the hydraulic servo drum. The improvement consists of: a support body made of light material having a first radially extending oil passage leading from an oil pressure controller for supplying and discharging a working oil and communicating with the inner peripheral surface of the tubular supporting portion; an inner sleeve of a heavier material than the support body fitting on the inner peripheral surface of the tubular supporting portion to cover the inner axially extending oil groove thereby forming an oil passage for working oil; and an outer sleeve of a heavier material than the support body fitting on the outer peripheral surface of the tubular supporting portion.

Kobayashi, K.; Sumiya, K.; Taga, Y.; Watanabe, K.

1987-09-15

456

Young adult smokers’ perceptions of cigarette pack innovation, pack colour and plain packaging  

Microsoft Academic Search

In jurisdictions where most forms of marketing tobacco are prohibited by law, such as the United Kingdom (UK), the tobacco industry is increasingly turning to innovative packaging to promote their products. Using focus group research we explored perceptions of packaging innovation (including cigarette packs with novel shapes and method of opening), and also plain packaging (all branding removed), among 54

Crawford Moodie; Allison Ford

2011-01-01

457

Optimal Packing of a Rotating Packed Bed for H2S Removal.  

PubMed

The existence of H2S in a system could lead to catalyst deactivation, pipeline corrosion, and environmental pollution. A rotating packed bed (RPB), a novel reactor with high mass transfer efficiency and small dimension, is employed in this study to remove H2S. For RPB, the most significant section for mass transfer is the end-effect zone of packing. A mathematical model for liquid flow in the packing is established to quantify the length of the end-effect zone. A simple and effective visual experimental method is then proposed to investigate the end-effect zone in the RPB. A gas-liquid mass transfer experiment is finally employed to confirm the validity of the proposed mathematical model. With the aid of this model, the length of packing of a RPB used for pilot-scale H2S removal is optimized. The optimized RPB removes 99.8% of H2S (15 vol % to 0.03 vol %) from the system. The proposed model can help optimize the design of a RPB reactor. PMID:24798198

Guo, Kai; Wen, Jiawu; Zhao, Ying; Wang, Yu; Zhang, Zhenzhen; Li, Zongxiang; Qian, Zhi

2014-06-17

458

Challenges in coupled thermal–hydraulics and neutronics simulations for LWR safety analysis  

Microsoft Academic Search

The simulation of nuclear power plant accident conditions requires three-dimensional (3D) modeling of the reactor core to ensure a realistic description of physical phenomena. The operational flexibility of Light Water Reactor (LWR) plants can be improved by utilizing accurate 3D coupled neutronics\\/thermal–hydraulics calculations for safety margins evaluations. There are certain requirements to the coupling of thermal–hydraulic system codes and neutron-kinetics

Kostadin Ivanov; Maria Avramova

2007-01-01

459

Extended Kalman filtering for battery management systems of LiPB-based HEV battery packs. Part 1. Background  

NASA Astrophysics Data System (ADS)

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 papers, we propose a method, based on extended Kalman filtering (EKF), that is able to accomplish these goals on a lithium-ion polymer battery pack. We expect that it will also work well on other battery chemistries. These papers cover the required mathematical background, cell modeling and system identification requirements, and the final solution, together with results. This first paper investigates the estimation requirements for HEV BMS in some detail, in parallel to the requirements for other battery-powered applications. The comparison leads us to understand that the HEV environment is very challenging on batteries and the BMS, and that precise estimation of some parameters will improve performance and robustness, and will ultimately lengthen the useful lifetime of the pack. This conclusion motivates the use of more complex algorithms than might be used in other applications. Our premise is that EKF then becomes a very attractive approach. This paper introduces the basic method, gives some intuitive feel to the necessary computational steps, and concludes by presenting an illustrative example as to the type of results that may be obtained using EKF.

Plett, Gregory L.

460

Experimental and computational analysis of random tetrahedral packings with applications  

NASA Astrophysics Data System (ADS)

Random packings are prevalent in chemical engineering applications and they can serve as prototype models of particulate materials. In this research, comprehensive studies on tetrahedral packings were carried out experimentally. Experiment was conducted on regular tetrahedral dice. MRI imaging was used to image the tetrahedral packs, an algorithm was developed which allowed us to retrieve each of the particle center positions as well as the 3D orientation from the digital data. To our best knowledge this is the first time that such an in-depth analysis was performed on non spherical objects. This numerical approach makes it possible to study detailed packing structure, packing density, the onset of ordering, and wall effects. Important applications for tetrahedral packings include multiphase flow in catalytic beds, heat transfer, bulk storage and transportation, and manufacturing of fibrous composites.

Jaoshvili, Alexander

461

Howling at two Minnesota wolf pack summer homesites  

USGS Publications Warehouse

Howling sessions were monitored at two Minnesota wolf pack homesites for 2255 h between 29 April and 3 August 1973. All sessions recorded occurred from dusk through early morning, with an evening peak for one pack. Within a night, multiple sessions were grouped temporally, most occurring within an hour of one another. Howling rates for both packs increased throughout the homesite season, with the larger pack howling twice as frequently. The role of howling in both intrapack and interpack contexts was considered. Much of the howling seemed to be involved in the coordination of pack activities. Further, the low frequency and clumped temporal distribution of sessions suggest that howling plays a secondary role in interpack contexts to other modes such as scent marking during the homesite season, but may increase in relative importance once homesites are abandoned and pack travel becomes nomadic.

Harrington, F .H.; Mech, L.D.

1978-01-01

462

Mechanistic pressure drop model for columns containing structured packings  

SciTech Connect

A mechanistic model was developed to predict pressure drop and flooding in packed columns equipped with corrugated packing of the regular type. It was developed after considering the interaction of falling liquid film with the gas phase, based on mass- and momentum-conservation equations. Among the most common structured packings, the behavior of the Mellapak and BX types was analyzed. The aim of this work is to demonstrate how mechanistic models, developed for simple geometry, can also be used to compute pressure drops in cases where the geometry is more complex, as with a structured packing. This approach, based on the geometric characteristics of the packing and measurable parameters such as liquid holdup, enables the development of a basic model by limiting the number of adjustable parameters, which are numerous in all the available models. Because of its nature, this model is extremely easy to extend to different types of structured packings.

Brunazzi, E.; Paglianti, A. [Industrial Chemistry and Materials Science, Pisa (Italy). Dept. of Chemical Engineering

1997-02-01

463

Flexible packing of arbitrary two-dimensional shapes  

NASA Astrophysics Data System (ADS)

A computational framework for the flexible packing of arbitrary planar shapes under visual control is described. Our aim in this work has been to produce an efficient packing strategy that is flexible enough for a wide variety of industrial uses and which can be implemented in fast, moderately priced hardware. We have deliberately adopted a systems approach, versus a purely algorithmic one, since we are concerned with industrial vision problems in which significant problem constraints exist. The packing procedure that we devised consists of two major components. The first is a geometric packing technique that is based on morphological image processing operations. This is used in conjunction with a heuristic packing procedure. The heuristic procedure also deals with problem constraints that are specific to a given application. The ideas outlined are currently being used in the development of a visually controlled intelligent packing work cell.

Whelan, Paul F.; Batchelor, Bruce G.

1993-12-01

464

Fluid Power Technician  

ERIC Educational Resources Information Center

Fluid power technicians, sometimes called hydraulic and pneumatic technicians, work with equipment that utilizes the pressure of a liquid or gas in a closed container to transmit, multiply, or control power. Working under the supervision of an engineer or engineering staff, they assemble, install, maintain, and test fluid power equipment.…

Moore, Pam

2008-01-01

465

Transmittance Enhancement of Packed-Bed Particulate Media  

Microsoft Academic Search

The optical thickness of highly attenuating packed-bed particulate media can be signifi- cantly reduced and, consequently, the radiation heat transfer enhanced, by the addition of large (>100 ?m) semi-transparent SiO2 particles. The monochromatic transmittance of packed-bed mixtures of SiO2, ZnO, and C particles of various relative mass fractions is experimentally measured as a function of the packed-bed thickness using a

W. Lipinski; E. Guillot; G. Olalde; A. Steinfeld

2008-01-01

466

A Non-Wetting Packed Bed Gas Scrubber  

Microsoft Academic Search

The operation of a small-scale packed column working under non-wetting condition was investigated to provide insight and design data for the subsequent development of a liquid metal irrigated packed bed gas scrubber. An 8cm internal diameter Perspex column was used, packed with 9.5mm polyethylene spheres and 10.0mm glass spheres coated with paraffin wax. A counter-current air–water system was used. The

B. F. Chang; J. Swithenbank; V. N. Sharifi

2007-01-01

467

Correlate the flooding of packed columns a new way  

Microsoft Academic Search

Packed-column pressure-drop and flooding-point prediction has received new attention recently. These publications, like most earlier ones, focus on gas-flow-induced pressure drop, and flooding due to liquid entrainment in the packing. A few years ago, some problems occurred when packing was applied in high-pressure distillation service, such as ethylene and propylene superfractionators. Apparently, the maximum liquid-through-put capacity was lower than predicted

1994-01-01

468

PackBot: A Versatile Platform for Military Robotics  

Microsoft Academic Search

The iRobot PackBot is a combat-tested, man-portable UGV that has been deployed in Afghanistan and Iraq. The PackBot is also a versatile platform for mobile robotics research and development that supports a wide range of payloads suitable for many different mission types. In this paper, we describe four R&D projects that developed experimental payloads and software using the PackBot platform.

Brian Yamauchi

469

PackBot: a versatile platform for military robotics  

Microsoft Academic Search

The iRobot PackBot is a combat-tested, man-portable UGV that has been deployed in Afghanistan and Iraq. The PackBot is also a versatile platform for mobile robotics research and development that supports a wide range of payloads suitable for many different mission types. In this paper, we describe four R&D projects that developed experimental payloads and software using the PackBot platform.

Brian M. Yamauchi

2004-01-01

470

Fixed Packed Bed Reactors in Reduced Gravity  

NASA Technical Reports Server (NTRS)

We present experimental data on flow pattern transitions, pressure drop and flow characteristics for cocurrent gas-liquid flow through packed columns in microgravity. The flow pattern transition data indicates that the pulse flow regime exists over a wider range of gas and liquid flow rates under microgravity conditions compared to 1-g and the widely used Talmor map in 1-g is not applicable for predicting the transition boundaries. A new transition criterion between bubble and pulse flow in microgravity is proposed and tested using the data. Since there is no static head in microgravity, the pressure drop measured is the true frictional pressure drop. The pressure drop data, which has much smaller scatter than most reported 1-g data clearly shows that capillary effects can enhance the pressure drop (especially in the bubble flow regime) as much as 200% compared to that predicted by the single phase Ergun equation. The pressure drop data are correlated in terms of a two-phase friction factor and its dependence on the gas and liquid Reynolds numbers and the Suratman number. The influence of gravity on the pulse amplitude and frequency is also discussed and compared to that under normal gravity conditions. Experimental work is planned to determine the gas-liquid mass transfer coefficients. Because of enhanced interfacial effects, we expect the gas-liquid transfer coefficients k(L)a and k(G)a (where a is the gas-liquid interfacial area) to be higher in microgravity than in normal gravity at the same flow conditions. This will be verified by gas absorption experiments, with and without reaction in the liquid phase, using oxygen, carbon dioxide, water and dilute aqueous amine solutions. The liquid-solid mass transfer coefficient will also be determined in the bubble as well as the pulse flow regimes using solid benzoic acid particles in the packing and measuring their rate of dissolution. The mass transfer coefficients in microgravity will be compared to those in normal gravity cocurrent flow to determine the mass transfer enhancement and propose new mass transfer correlations for two-phase gas-liquid flows through packed beds in microgravity.

Motil, Brian J.; Balakotaiah, Vemuri; Kamotani, Yasuhiro; McCready, Mark J.

2004-01-01

471

Fixed Packed Bed Reactors in Reduced Gravity  

NASA Technical Reports Server (NTRS)

We present experimental data on flow pattern transitions, pressure drop and flow characteristics for cocurrent gas-liquid flow through packed columns in microgravity. The flow pattern transition data indicates that the pulse flow regime exists over a wider range of gas and liquid flow rates under microgravity conditions compared to 1-g and the widely used Talmor map in 1-g is not applicable for predicting the transition boundaries. A new transition criterion between bubble and pulse flow in microgravity is proposed and tested using the data. Since there is no static head in microgravity, the pressure drop measured is the true frictional pressure drop. The pressure drop data, which has much smaller scatter than most reported 1-g data clearly shows that capillary effects can enhance the pressure drop (especially in the bubble flow regime) as much as 200% compared to that predicted by the single phase Ergun equation. The pressure drop data are correlated in terms of a two-phase friction factor and its dependence on the gas and liquid Reynolds numbers and the Suratman number. The influence of gravity on the pulse amplitude and frequency is also discussed and compared to that under normal gravity conditions. Experimental work is planned to determine the gas-liquid and liquid-solid mass transfer coefficients. Because of enhanced interfacial effects, we expect the gas-liquid transfer coefficients kLa and kGa (where a is the gas-liquid interfacial area) to be higher in microgravity than in normal gravity at the same flow conditions. This will be verified by gas absorption experiments, with and without reaction in the liquid phase, using oxygen, carbon dioxide, water and dilute aqueous amine solutions. The liquid-solid mass transfer coefficient will also be determined in the bubble as well as the pulse flow regimes using solid benzoic acid particles in the packing and measuring their rate of dissolution. The mass transfer coefficients in microgravity will be compared to those in normal gravity cocurrent flow to determine the mass transfer enhancement and propose new mass transfer correlations for two-phase gas-liquid flows through packed beds in microgravity.

Motil, Brian J.; Balakotaiah, Vemuri; Kamotani, Yasuhiro; McCready, Mark J.

2004-01-01

472

PILOT-SCALE HYDRAULIC TESTING OF RESORCINOL FORMALDEHYDE ION EXCHANGE RESIN  

SciTech Connect

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.

Adamson, D.

2009-05-28

473

H2 production with anaerobic sludge using activated-carbon supported packed-bed bioreactors.  

PubMed

Packed-bed bioreactors containing activated carbon as support carrier were used to produce H2 anaerobically from a sucrose-limiting medium while acclimated sewage sludge was used as the H2 producer. The effects of bed porosity (epsilon(b)) and substrate loading rate on H2 fermentation were examined using packed beds with epsilon(b) of 70-90% being operated at hydraulic retention times (HRT) of 0.5-4 h. Higher epsilon(b) and lower HRT favored H2 production. With 20 g COD l(-1) of sucrose in the feed, the optimal H2 production rate (7.4 l h(-1) l(-1)) was obtained when the bed with epsilon(b) = 90% was operated at HRT = 0.5 h. Flocculation of cells enhanced the retention of sludge for stable operations of the bioreactor at low HRTs. The gas products resulting from fermentative H2 production consisted of 30-40% H2 and 60-70% CO2. Butyric acid was the primary soluble product, followed by propionic acid and valeric acid. PMID:12882288

Lee, Kuo-Shing; Lo, Yung-Sheng; Lo, Yung-Chung; Lin, Ping-Jei; Chang, Jo-Shu

2003-01-01

474

Theory and application of drilling fluid hydraulics  

SciTech Connect

The objectives of this book are (1) to serve as a reasonably comprehensive text on the subject of drilling hydraulics and (2) to provide the field geologist with a quick reference to drilling hydraulics calculations. Chapter 1 introduces the basic principles of fluid properties, and Chapter 2 presents the general principles of fluid hydraulics. Chapters 3 through 10 analyze specific hydraulic considerations of the drilling process, such as viscometric measurements, pressure losses, swab and surge pressures, cuttings transport and hydraulic optimization. The units and nomenclature are consistent throughout the manual. Equations are given generally in consistent S.I. units; some common expressions are also given in oilfield units. Nomenclature is explained after every equation when necessary, and a comprehensive list of the nomenclature used is given in Appendix A. Units are listed in Appendix B. In Appendix C, all the important equations are given in both S.I. and oilfield units. Appendix D contains example hydraulics calculations.

Whittaker, A.

1985-01-01

475

Combined hydraulic and regenerative braking system  

DOEpatents

A combined hydraulic and regenerative braking system and method for an electric vehicle, with the braking system being responsive to the applied hydraulic pressure in a brake line to control the braking of the vehicle to be completely hydraulic up to a first level of brake line pressure, to be partially hydraulic at a constant braking force and partially regenerative at a linearly increasing braking force from the first level of applied brake line pressure to a higher second level of brake line pressure, to be partially hydraulic at a linearly increasing braking force and partially regenerative at a linearly decreasing braking force from the second level of applied line pressure to a third and higher level of applied line pressure, and to be completely hydraulic at a linearly increasing braking force from the third level to all higher applied levels of line pressure.

Venkataperumal, Rama R. (Troy, MI); Mericle, Gerald E. (Mount Clemens, MI)

1981-06-02

476

14 CFR 27.695 - Power boost and power-operated control system.  

Code of Federal Regulations, 2010 CFR

...power portion includes the power source (such as hydraulic pumps), and such items as valves, lines, and actuators. (c) The failure of mechanical parts (such as piston rods and links), and the jamming of power...

2009-01-01

477

14 CFR 27.695 - Power boost and power-operated control system.  

Code of Federal Regulations, 2010 CFR

...power portion includes the power source (such as hydraulic pumps), and such items as valves, lines, and actuators. (c) The failure of mechanical parts (such as piston rods and links), and the jamming of power...

2010-01-01

478

Heavy metal removal by combining anaerobic upflow packed bed reactors with water hyacinth ponds.  

PubMed

The removal of four selected heavy metals (Cu, Cd, Pb and Zn) has been assessed in an upflow anaerobic packed bed reactor filled with porous volcanic rock as an adsorbent and an attachment surface for bacterial growth. Two different feeding regimes were applied using low (5 mg L(-1) of heavy metal each) and high (10 mg L(-1) of heavy metal each) strength wastewater. After a start-up and acclimatization period of 44 days, each regime was operated for a period of 10 days with a hydraulic retention time of one day. Good removal efficiencies of at least 86% were achieved for both the low and high strength wastewater. A subsequent water hyacinth pond with a hydraulic retention time of one day removed an additional 61% Cd, 59% Cu, 49% Pb and 42% Zn, showing its importance as a polishing step. The water hyacinth plant in the post-treatment step accumulated heavy metals mainly in the root system. Overall metal removal efficiencies at the outlet of the integrated system were 98% for Cd, 99% for Cu, 98% for Pb and 84% for Zn. Therefore, the integrated system can be used as an alternative treatment system for metal-polluted wastewater, especially in developing countries. PMID:22856321

Sekomo, Christian Birame; Kagisha, Vedaste; Rousseau, Diederik; Lens, Piet

2012-06-01

479

Performance characteristics of an electric vehicle lead-acid battery pack at elevated temperatures  

NASA Technical Reports Server (NTRS)

Discharge testing data electric car battery pack over initial electrolyte temperature variations between 27 and 55 C are presented. The tests were conducted under laboratory conditions and then compared to detailed electric vehicle simulation models. Battery discharge capacity increased with temperature for constant current discharges, and battery energy capacity increased with temperature for constant power discharges. Dynamometer tests of the electric test vehicle showed an increase in range of 25% for the higher electrolyte temperature.

Chapman, P.

1982-01-01

480

Performance characteristics of an electric vehicle lead-acid battery pack at elevated temperatures  

NASA Astrophysics Data System (ADS)

Discharge testing data electric car battery pack over initial electrolyte temperature variations between 27 and 55 C are presented. The tests were conducted under laboratory conditions and then compared to detailed electric vehicle simulation models. Battery discharge capacity increased with temperature for constant current discharges, and battery energy capacity increased with temperature for constant power discharges. Dynamometer tests of the electric test vehicle showed an increase in range of 25% for the higher electrolyte temperature.

Chapman, P.

1982-04-01

481

Numerically predicting seepage gradient forces and erosion: Sensitivity to soil hydraulic properties  

NASA Astrophysics Data System (ADS)

SummaryResearch has suggested that streambank seepage can be an important mechanism of bank instability; however, limited information is available on the level of soil characterization necessary to accurately predict seepage gradient forces and erosion. The objective of this research was to quantify the expected range of predicted seepage gradients for various degrees of site characterization. Uncertainty analysis on seepage gradient predictions was performed relative to variability in soil hydraulic properties. A two-dimensional unsaturated/saturated groundwater flow model was used to simulate a homogeneous soil layer for sand and loamy sand soils packed at various bulk densities, ? b. A pedotransfer function (ROSETTA), designed to estimate unsaturated hydraulic properties from surrogate soil data (i.e., texture and bulk density), was used to derive the saturated hydraulic conductivity, K s, and water retention parameters for various levels of site information (i.e., only textural class; percent sand, silt, and clay (%SSC); %SSC and ? b; and %SSC, ? b, and K s). Statistical distributions were derived for each soil hydraulic parameter and Monte Carlo simulations were performed to generate distributions of maximum seepage gradient. The deviation in predicted seepage gradient was calculated using assumed baseline conditions. Ranges in predicted soil hydraulic parameters and maximum seepage gradients were considerably reduced when using %SSC as compared to soil texture. Therefore, at a minimum, soil samples should be taken for particle size analysis. For ? b between 1450 and 1500 kg m -3, soil hydraulic parameters could be derived using ROSETTA and inputting %SSC, with little additional benefit provided by measuring ? b and/or K s. When the ? b was less than 1450-1500 kg m -3, inputting ? b and/or K s consistently reduced the magnitude of deviations from the baseline and therefore should be measured from undisturbed soil samples. The opposite was observed for ? b greater than 1450-1500 kg m -3 due to discrepancies between ROSETTA-derived and actual values of soil hydraulic parameters other than K s. Considerable deviations (i.e., around 20%) were observed in seepage gradients under this scenario. When ROSETTA-derived and actual values of soil hydraulic parameters more closely matched, inputting ? b and/or K s benefitted seepage gradient predictions as deviations in seepage gradients were less than 5% for the sand and loamy sand soils. Therefore, it is vital to quantify all soil hydraulic parameters for high ? b soils and textures with a wide range in %SSC.

Fox, Garey A.; Heeren, Derek M.; Wilson, Glenn V.; Langendoen, Eddy J.; Fox, Amanda K.; Chu-Agor, Maria L.

2010-08-01

482

New Packing Structure of Concentration Solar Receiver  

SciTech Connect

This paper presents a solution to the temperature issue in High Concentration Photovoltaic (HCPV) module device by using different thermal conductive material and packing structure. In general, the open-circuited voltage of a device reduces with the increase of temperature and therefore degrades its efficiency. The thermal conductive material we use in this paper, silicon, has a high thermal conductive coefficient (149 W/m{center_dot}K) and steady semiconductor properties which are suitable for the application of solar receiver in HCPV module. Solar cell was soldered on a metal-plated Si substrate with a thicker SiO{sub 2} film which acts as an insulating layer. Then it was mounted on an Al-based plate to obtain a better heat dissipating result.

Tsai, Shang-Yu; Lee, Yueh-Mu; Shih, Zun-Hao; Hong, Hwen-Fen; Shin, Hwa-Yuh; Kuo, Cherng-Tsong

2010-10-14

483

Probe with integrated heater and thermocouple pack  

SciTech Connect

A gamma thermometer probe for detecting heat produced within the thermometer probe is described comprising: an outer elongate thermometer sheath having a cylindrical cross-section, a length, an outer end and an inner end; an elongate rod having a cylindrical cross-section fitted within the elongate thermometer sheath, the rod being constructed of material that absorbs radiation and produces heat; annular recesses formed between the rod, and sheath and being spaced apart along the length of the rod, the recesses forming annular chambers that are resistive to heat flow; a longitudinal bore extending axially into the rod and being positioned to extend through the cylinders defined by the annular chambers; and an integrated thermocouple pack dimensioned to fit within the longitudinal bore and extending through the cylinders defined by the annular chambers.

McCulloch, R.W.; Dial, R.E.; Finnell, W.R.

1988-02-16

484

Packing C60 in boron nitride nanotubes.  

PubMed

We have created insulated C60 nanowire by packing C60 molecules into the interior of insulating boron nitride nanotubes (BNNTs). For small-diameter BNNTs, the wire consists of a linear chain of C60 molecules.With increasing BNNT inner diameter, unusual C60 stacking configurations are obtained (including helical, hollow core, and incommensurate) that are unknown for bulk or thin-film forms of C60.C60 in BNNTs thus presents a model system for studying the properties of dimensionally constrained "silo" crystal structures. For the linear-chain case,