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Sample records for electrically small cylinder

  1. Static imaging of the electrical impedance tomography on cylinder physical phantom.

    PubMed

    Liu, Ruigang; Fu, Feng; You, Fusheng; Shi, Xuetao; Dong, Xiuzhen

    2015-01-01

    Static imaging of the electrical impedance tomography can obtain the absolute electrical conductivity distribution at one section of the subject. The test is performed on a cylinder physical phantom in which slim rectangle, hollow cylinder, small rectangle or three cylinders are selected to simulate complex conductivity perturbation objects. The measurement data is obtained by a data acquisition system with 32 compound electrodes. A group of static images of conductivity distribution in the cylinder phantom are reconstructed by the modified Newton-Raphson algorithm with two kinds of regularization methods. The results show correct position, size, conductivity difference, and similar shape of the perturbation objects in the images.

  2. Assembly for electrical conductivity measurements in the piston cylinder device

    DOEpatents

    Watson, Heather Christine; Roberts, Jeffrey James

    2012-06-05

    An assembly apparatus for measurement of electrical conductivity or other properties of a sample in a piston cylinder device wherein pressure and heat are applied to the sample by the piston cylinder device. The assembly apparatus includes a body, a first electrode in the body, the first electrode operatively connected to the sample, a first electrical conductor connected to the first electrode, a washer constructed of a hard conducting material, the washer surrounding the first electrical conductor in the body, a second electrode in the body, the second electrode operatively connected to the sample, and a second electrical conductor connected to the second electrode.

  3. Small plastic piston-cylinder cell for pulsed magnetic field studies at cryogenic temperatures

    NASA Astrophysics Data System (ADS)

    Coniglio, William A.; Graf, David E.; Tozer, Stanley W.

    2013-06-01

    A plastic piston-cylinder cell based on a thick wall test-tube has been designed for pulsed magnetic field studies. The small 12.7 mm diameter and overall height of 19.3 mm allow the cell to freely rotate in a cryostat with a diameter of 21.5 mm. Electrical leads, coax cable or microstrip transmission lines can be introduced into the pressure chamber for a variety of measurements such as electrical transport, de Haas-van Alphen, Shubnikov-de Haas and Hall effect. A fiber optic has been introduced for the purpose of calibrating the pressure via a ruby manometer. The fiber optic opens up additional experimental techniques such as photoluminescence, photoconductivity and, with use of a special fiber with a Bragg grating, magnetostriction and thermal expansion. Maximum pressures of 0.35 GPa at room temperature have been obtained.

  4. Near- and far-field scattering resonance frequency shift in dielectric and perfect electric conducting cylinders.

    PubMed

    Yuffa, Alex J; Gutierrez, Yael; Sanz, Juan M; Alcaraz de la Osa, Rodrigo; Saiz, José M; González, Francisco; Moreno, Fernando; Videen, Gorden

    2016-03-01

    The ability to infer near-field scattering properties from far-field measurements is of paramount importance in nano-optics. Recently we derived an approximate formula for predicting the frequency shift between near- and far-field intensity peaks in the case of a dielectric sphere. In this work we demonstrate that almost an identical formula can be used to predict the resonance shift of a dielectric cylinder and a perfectly conducting cylinder. We find the redshift of the resonance peak of the perfect electric conducting cylinder to be approximately 2 orders of magnitude greater than for the dielectric cylinder. The errors in our approximate analytic formula for predicting the redshift are approximately only twice as great. Furthermore, we apply the redshift formula to a silicon cylinder and discuss its magneto-dielectric properties, which may be of interest in design of metamaterials. PMID:26974908

  5. 49 CFR 178.61 - Specification 4BW welded steel cylinders with electric-arc welded longitudinal seam.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 4BW cylinder is a welded type steel cylinder with a longitudinal electric-arc welded seam, a water....60, Phosphorus 0.045, Sulfur 0.050. Heads must be hemispherical or ellipsoidal in shape with a...) Hydrostatic test. Cylinders must withstand a hydrostatic test, as follows: (1) The test must be by...

  6. 49 CFR 178.61 - Specification 4BW welded steel cylinders with electric-arc welded longitudinal seam.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 4BW cylinder is a welded type steel cylinder with a longitudinal electric-arc welded seam, a water..., Manganese 0.60, Phosphorus 0.045, Sulfur 0.050. Heads must be hemispherical or ellipsoidal in shape with a...) Hydrostatic test. Cylinders must withstand a hydrostatic test, as follows: (1) The test must be by...

  7. 49 CFR 178.61 - Specification 4BW welded steel cylinders with electric-arc welded longitudinal seam.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 4BW cylinder is a welded type steel cylinder with a longitudinal electric-arc welded seam, a water....60, Phosphorus 0.045, Sulfur 0.050. Heads must be hemispherical or ellipsoidal in shape with a...) Hydrostatic test. Cylinders must withstand a hydrostatic test, as follows: (1) The test must be by...

  8. Wake flow pattern modified by small control cylinders at low Reynolds number

    NASA Astrophysics Data System (ADS)

    Kuo, C.-H.; Chiou, L.-C.; Chen, C.-C.

    2007-08-01

    Passive wake control behind a circular cylinder in uniform flow is studied by numerical simulation for ReD ranging from 80 to 300. Two small control cylinders, with diameter d/D=1/8, are placed at x/D=0.5 and y/D=±0.6. Unlike the 1990 results of Strykowski and Sreenivasan, in the present study, the vortex street behind the main cylinder still exists but the fluctuating lift and the form drag on the main cylinder reduces significantly and monotonously as the Reynolds number increases from 80 to 300. Obstruction of the control cylinders to the incoming flow deflects part of the fluid to pass through the gap between the main and control cylinders, forming two symmetric streams. These streams not only eliminate the flow separation along the rear surface of the main cylinder, they also merge toward the wake centerline to create an advancing momentum in the immediate near-wake region. These two effects significantly reduce the wake width behind the main cylinder and lead to monotonous decrease of the form drag as the Reynolds number increases. As the Reynolds number gets higher, a large amount of the downstream advancing momentum significantly delays the vortex formation farther downstream, leading to a more symmetric flow structure in the near-wake region of the main cylinder. As the Reynolds number increases from 80 to 300, both increasing symmetry of the flow structure in the near-wake and significant delay of the vortex formation are the main reasons for the fluctuating lift to decrease monotonously.

  9. Development status on a TPV cylinder for combined heat and electric power for the home

    NASA Astrophysics Data System (ADS)

    Fraas, Lewis; Samaras, John; Huang, Han-Xiang; Seal, Michael; West, Edward

    1999-03-01

    Several first-generation water-cooled TPV cylinders have been built and tested. The existing units contain 380 GaSb cells mounted on 20 circuits; the design and test results on these photovoltaic converter arrays are presented here. Tested with a 1600 °C glowbar, one of these cylinders generated 990 Watts from a cell active area of 396 cm2, which is an electric power density of 2.5 Watts per cm2. A second-generation design is presented, using a new shingled circuit assembly. These shingled circuits allow for a slightly larger cylinder design with nearly double the cell active area. Using a SiC emitter operating at 1425 °C, this second-generation cylinder should produce over 1.5 kW of power with improved efficiency.

  10. Simulation of evolution of the two cylinders plasma wake under the electric discharge influence

    NASA Astrophysics Data System (ADS)

    Gembarzhevskii, G. V.; Lednev, A. K.; Osipenko, K. Yu.

    2015-12-01

    We consider a close wake behind a pair of cylinders at a Reynolds number of Re ~ 1000 defined by the cylinder diameter in the case of small aspect ratio of cylinders, H/D ≈ 3.5. The large-scale structure of such a wake represents a f low like two interacting Karman streets and it is modeled by two coupled Van der Pol oscillators. The mutual inf luence of closely located Karman streets is accounted for by nonlinear (of a general parabolic type) terms in the equations for oscillators. Moreover, the equations are generalized with allowance for explicit dependence of the oscillation frequency on its amplitude. Within the framework of this three-parametric model, five collective modes of the wake behind cylinders were found. In addition, there are the domains of model parameters where qualitatively different modes of intermittent wake exist.

  11. Drag measurements on long thin cylinders at small angles and high Reynolds numbers

    NASA Astrophysics Data System (ADS)

    Keith, William L.; Cipolla, Kimberly M.; Hart, David R.; Furey, Deborah A.

    2005-06-01

    Measurements of the drag caused by turbulent boundary layer mean wall shear stress on cylinders at small angles of attack and high length Reynolds numbers (8×106cylinders made of stainless steel, aluminum, titanium, and polyvinyl chloride. The diameter of all cylinders in this experiment was 12.7 mm; two cylinder lengths, 3.05 m and 6.10 m, were used, corresponding to aspect ratio values L/a=480 and 960, respectively. Materials of various densities were towed at critical angles, resulting in linear cylinder geometry for tow speeds ranging from 2.6 m/s to 20.7 m/s and angles between 0° and 12°. Towing angles were measured with digital photography, and streamwise drag was measured with a strut-mounted load cell at the tow point. The measured tangential drag was very sensitive to small increases in angle at all tow speeds. A momentum thickness length scale is proposed to scale the tangential drag coefficient. The effects of the cross-flow resulting from the small angles of tow have a significant effect on the tangential drag coefficient values. A scaling for the orthogonal force on the cylinders was determined and provides a correction to published normal drag coefficient values for pure cross-flow. The presence of the axial turbulent boundary layer has a significant effect on these orthogonal forces.

  12. Electric propulsion for small satellites

    NASA Astrophysics Data System (ADS)

    Keidar, Michael; Zhuang, Taisen; Shashurin, Alexey; Teel, George; Chiu, Dereck; Lukas, Joseph; Haque, Samudra; Brieda, Lubos

    2015-01-01

    Propulsion is required for satellite motion in outer space. The displacement of a satellite in space, orbit transfer and its attitude control are the task of space propulsion, which is carried out by rocket engines. Electric propulsion uses electric energy to energize or accelerate the propellant. The electric propulsion, which uses electrical energy to accelerate propellant in the form of plasma, is known as plasma propulsion. Plasma propulsion utilizes the electric energy to first, ionize the propellant and then, deliver energy to the resulting plasma leading to plasma acceleration. Many types of plasma thrusters have been developed over last 50 years. The variety of these devices can be divided into three main categories dependent on the mechanism of acceleration: (i) electrothermal, (ii) electrostatic and (iii) electromagnetic. Recent trends in space exploration associate with the paradigm shift towards small and efficient satellites, or micro- and nano-satellites. A particular example of microthruster considered in this paper is the micro-cathode arc thruster (µCAT). The µCAT is based on vacuum arc discharge. Thrust is produced when the arc discharge erodes some of the cathode at high velocity and is accelerated out the nozzle by a Lorentz force. The thrust amount is controlled by varying the frequency of pulses with demonstrated range to date of 1-50 Hz producing thrust ranging from 1 µN to 0.05 mN.

  13. Lock-on characteristics behind two side-by-side cylinders of diameter ratio two at small gap ratio

    NASA Astrophysics Data System (ADS)

    Lee, Petry Y. R.; Lu, Wei-Ting; Chou, Shy-Tsin; Kuo, Cheng-Hsiung

    2012-10-01

    The lock-on characteristics, the detailed interactions and downstream evolutions of the wakes behind side-by-side cylinders of unequal diameter ( D/ d = 2), spaced by a gap ratio 0.75 ( G/ D = 0.75), are investigated at Reynolds number 600 by the dye flow visualization, laser Doppler anemometry (LDA) and particle image velocimeter (PIV) velocity measurements. The lock-on frequency bands are studied by LDA and PIV at Reynolds number 2,000. The D, d and G are the diameters of the large, the small cylinders and the net gap between two cylinders, respectively. Periodic excitations, in form of rotary oscillation about the cylinder center, are applied to the large cylinder with the same amplitude. It is found that while the large cylinder is excited, two lock-on frequency bands of the wake behind the large cylinder are detected. These two lock-on frequency bands correspond to the primary and the one-third sub-harmonic lock-on of the wake behind large cylinder, respectively. These two lock-on frequency bands distribute symmetrically about the fundamental and the third superharmonic of the natural shedding frequency behind a single cylinder at the same Reynolds number. The left-shifted frequency band (1.8 ≤ f e / f os ≤ 2.0) is not considered as a locked-on frequency band because the phase difference between two excitation frequencies across f e / f os = 2.0 vary significantly. While the wake behind the large cylinder is locked-on at f e /3 (or f os ), the gap flow becomes unbiased and the frequency of the wake behind small cylinder remains around the natural shedding frequency. Thus, the frequency band of 3.0 ≤ f e / f os ≤ 3.22 is also not locked-on because the phase difference in the narrow wake excited at f e / f os = 2.93 and 3.07 changes significantly. Note f e and f os denote the excitation frequency and the natural shedding frequency behind a single large cylinder, respectively.

  14. Drag force and transport property of a small cylinder in free molecule flow: A gas-kinetic theory analysis

    NASA Astrophysics Data System (ADS)

    Liu, Changran; Li, Zhigang; Wang, Hai

    2016-08-01

    Analytical expressions are derived for aerodynamic drag force on small cylinders in the free molecule flow using the gas-kinetic theory. The derivation considers the effect of intermolecular interactions between the cylinder and gas media. Two limiting collision models, specular and diffuse scattering, are investigated in two limiting cylinder orientations with respect to the drift velocity. The earlier solution of Dahneke [B. E. Dahneke, J. Aerosol Sci. 4, 147 (1973), 10.1016/0021-8502(73)90066-9] is shown to be a special case of the current expressions in the rigid-body limit of collision. Drag force expressions are obtained for cylinders that undergo Brownian rotation and for those that align with the drift velocity. The validity of the theoretical expressions is tested against experimental mobility data available for carbon nanotubes.

  15. Drag force and transport property of a small cylinder in free molecule flow: A gas-kinetic theory analysis.

    PubMed

    Liu, Changran; Li, Zhigang; Wang, Hai

    2016-08-01

    Analytical expressions are derived for aerodynamic drag force on small cylinders in the free molecule flow using the gas-kinetic theory. The derivation considers the effect of intermolecular interactions between the cylinder and gas media. Two limiting collision models, specular and diffuse scattering, are investigated in two limiting cylinder orientations with respect to the drift velocity. The earlier solution of Dahneke [B. E. Dahneke, J. Aerosol Sci. 4, 147 (1973)10.1016/0021-8502(73)90066-9] is shown to be a special case of the current expressions in the rigid-body limit of collision. Drag force expressions are obtained for cylinders that undergo Brownian rotation and for those that align with the drift velocity. The validity of the theoretical expressions is tested against experimental mobility data available for carbon nanotubes.

  16. Drag force and transport property of a small cylinder in free molecule flow: A gas-kinetic theory analysis.

    PubMed

    Liu, Changran; Li, Zhigang; Wang, Hai

    2016-08-01

    Analytical expressions are derived for aerodynamic drag force on small cylinders in the free molecule flow using the gas-kinetic theory. The derivation considers the effect of intermolecular interactions between the cylinder and gas media. Two limiting collision models, specular and diffuse scattering, are investigated in two limiting cylinder orientations with respect to the drift velocity. The earlier solution of Dahneke [B. E. Dahneke, J. Aerosol Sci. 4, 147 (1973)10.1016/0021-8502(73)90066-9] is shown to be a special case of the current expressions in the rigid-body limit of collision. Drag force expressions are obtained for cylinders that undergo Brownian rotation and for those that align with the drift velocity. The validity of the theoretical expressions is tested against experimental mobility data available for carbon nanotubes. PMID:27627388

  17. 30 CFR 75.1106-6 - Exemption of small low pressure gas cylinders containing nonflammable or nonexplosive gas mixtures.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Exemption of small low pressure gas cylinders containing nonflammable or nonexplosive gas mixtures. 75.1106-6 Section 75.1106-6 Mineral Resources MINE... STANDARDS-UNDERGROUND COAL MINES Fire Protection § 75.1106-6 Exemption of small low pressure gas...

  18. 30 CFR 75.1106-6 - Exemption of small low pressure gas cylinders containing nonflammable or nonexplosive gas mixtures.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Exemption of small low pressure gas cylinders containing nonflammable or nonexplosive gas mixtures. 75.1106-6 Section 75.1106-6 Mineral Resources MINE... STANDARDS-UNDERGROUND COAL MINES Fire Protection § 75.1106-6 Exemption of small low pressure gas...

  19. 30 CFR 75.1106-6 - Exemption of small low pressure gas cylinders containing nonflammable or nonexplosive gas mixtures.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Exemption of small low pressure gas cylinders containing nonflammable or nonexplosive gas mixtures. 75.1106-6 Section 75.1106-6 Mineral Resources MINE... STANDARDS-UNDERGROUND COAL MINES Fire Protection § 75.1106-6 Exemption of small low pressure gas...

  20. 30 CFR 75.1106-6 - Exemption of small low pressure gas cylinders containing nonflammable or nonexplosive gas mixtures.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Exemption of small low pressure gas cylinders containing nonflammable or nonexplosive gas mixtures. 75.1106-6 Section 75.1106-6 Mineral Resources MINE... STANDARDS-UNDERGROUND COAL MINES Fire Protection § 75.1106-6 Exemption of small low pressure gas...

  1. 30 CFR 75.1106-6 - Exemption of small low pressure gas cylinders containing nonflammable or nonexplosive gas mixtures.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Exemption of small low pressure gas cylinders containing nonflammable or nonexplosive gas mixtures. 75.1106-6 Section 75.1106-6 Mineral Resources MINE... STANDARDS-UNDERGROUND COAL MINES Fire Protection § 75.1106-6 Exemption of small low pressure gas...

  2. Characterization of Single-Cylinder Small-Bore 4-Stroke CIDI Engine Combustion

    SciTech Connect

    Henein, N A

    2005-11-30

    Direct injection diesel engines power most of the heavy-duty vehicles. Due to their superior fuel economy, high power density and low carbon dioxide emissions, turbocharged, small bore, high speed, direct injection diesel engines are being considered to power light duty vehicles. Such vehicles have to meet stringent emission standards. However, it is difficult to meet these standards by modifying the in-cylinder thermodynamic and combustion processes to reduce engine-out emissions. After-treatment devices will be needed to achieve even lower emission targets required in the production engines to account for the anticipated deterioration after long periods of operation in the field. To reduce the size, mass and cost of the after-treatment devices, there is a need to reduce engine-out emissions and optimize both the engine and the aftertreatment devices as one integrated system. For example, the trade-off between engine-out NOx and PM, suggests that one of these species can be minimized in the engine, with a penalty in the other, which can be addressed efficiently in the after-treatment devices. Controlling engine-out emissions can be achieved by optimizing many engine design and operating parameters. The design parameters include, but are not limited to, the type of injection system: (CRS) Common Rail System, (HEUI ) Hydraulically Actuated and Electronically controlled Unit Injector, or (EUI) Electronic Unit Injector; engine compression ratio, combustion chamber design (bowl design), reentrance geometry, squish area and intake and exhaust ports design. With four-valve engines, the swirl ratio depends on the design of both the tangential and helical ports and their relative locations. For any specific engine design, the operating variables need also to be optimized. These include injection pressure, injection rate, injection duration and timing (pilot, main, and post injection), EGR ratio, and swirl ratio. The goal of the program is to gain a better understanding of

  3. Improved calculations of the electromechanical properties of tangentially poled stripe-electroded piezoelectric bars and cylinders with nonuniform electric fields.

    PubMed

    Sarangapani, Sairajan; Brown, David A

    2012-11-01

    Tangentially polarized stripe-electroded piezoelectric elements are often used to achieve the longitudinal piezoelectric effect without using segmented parts bonded together, however the electromechanical properties are not fully realized due to the nonuniform electric field and polarization in the element. The effective electromechanical coupling coefficient k(3'3eff), piezoelectric modulus d(3'3eff), elastic constant s(3'3eff)(E), and relative dielectric constant ε(3'3eff)(T) (where the prime denotes the nonuniform polarization) for tangentially polarized stripe-electroded bars and hollow cylinders are calculated using the energy method for the nonuniform electric field. A finite difference method is used to analyze the electric field under the assumption that the piezoelement is fully polarized. Results are compared with a piecewise linear field model and experimental results on representative piezoelements.

  4. Small-scale deflagration cylinder test with velocimetry wall-motion diagnostics

    SciTech Connect

    Hooks, Daniel E; Hill, Larry G; Pierce, Timothy H

    2010-01-01

    Predicting the likelihood and effects of outcomes resultant from thermal initiation of explosives remains a significant challenge. For certain explosive formulations, the general outcome can be broadly predicted given knowledge of certain conditions. However, there remain unexplained violent events, and increased statistical understanding of outcomes as a function of many variables, or 'violence categorization,' is needed. Additionally, the development of an equation of state equivalent for deflagration would be very useful in predicting possible detailed event consequences using traditional hydrodynamic detonation moders. For violence categorization, it is desirable that testing be efficient, such that it is possible to statistically define outcomes reliant on the processes of initiation of deflagration, steady state deflagration, and deflagration to detonation transitions. If the test simultaneously acquires information to inform models of violent deflagration events, overall predictive capabilities for event likelihood and consequence might improve remarkably. In this paper we describe an economical scaled deflagration cylinder test. The cyclotetramethylene tetranitramine (HMX) based explosive formu1lation PBX 9501 was tested using different temperature profiles in a thick-walled copper cylindrical confiner. This test is a scaled version of a recently demonstrated deflagration cylinder test, and is similar to several other thermal explosion tests. The primary difference is the passive velocimetry diagnostic, which enables measurement of confinement vessel wall velocities at failure, regardless of the timing and location of ignition.

  5. Feasibility of observing small differences in friction mean effective pressure between different lubricating oil formations using small, single-cylinder motored engine rig

    DOE PAGESBeta

    Rohr, William F.; Nguyen, Ke; Bunting, Bruce G.; Qu, Jun

    2015-09-01

    Here, the feasibility of using a motored single-cylinder 517 cc diesel engine to observe small frictional differences between oil formulations is investigated. Friction mean effective pressure (FMEP) is measured and compared for an SAE 10W-30 and an SAE 5W-20 oil in three stages of production: base oil, commercial oil without a friction and wear reducing additive, and fully formulated commercial oil. In addition, a commercial SAE 5W-30 engine oil is investigated. Friction mean effective pressure is plotted versus oil dynamic viscosity to compare the lubricant FMEP at a given viscosity. Linear regressions and average friction mean effective pressure are usedmore » as a secondary means of comparing FMEP for the various oil formulations. Differences between the oils are observed with the base oil having higher friction at a given viscosity but a lower average FMEP due to the temperature distribution of the test and lower viscosities reached by the base oil. The commercial oil is shown to have both a higher FMEP at a given viscosity and a higher average FMEP than the commercial oil without a friction and wear reducing additive. The increase in friction for the oil without a friction and wear reduction additive indicates that the operational regime of the engine may be out of the bounds of the optimal regime for the additive or that the additive is more optimized for wear reduction. Results show that it is feasible to observe small differences in FMEP between lubricating oil formulations using a small, single-cylinder motored engine.« less

  6. Feasibility of observing small differences in friction mean effective pressure between different lubricating oil formations using small, single-cylinder motored engine rig

    SciTech Connect

    Rohr, William F.; Nguyen, Ke; Bunting, Bruce G.; Qu, Jun

    2015-09-01

    Here, the feasibility of using a motored single-cylinder 517 cc diesel engine to observe small frictional differences between oil formulations is investigated. Friction mean effective pressure (FMEP) is measured and compared for an SAE 10W-30 and an SAE 5W-20 oil in three stages of production: base oil, commercial oil without a friction and wear reducing additive, and fully formulated commercial oil. In addition, a commercial SAE 5W-30 engine oil is investigated. Friction mean effective pressure is plotted versus oil dynamic viscosity to compare the lubricant FMEP at a given viscosity. Linear regressions and average friction mean effective pressure are used as a secondary means of comparing FMEP for the various oil formulations. Differences between the oils are observed with the base oil having higher friction at a given viscosity but a lower average FMEP due to the temperature distribution of the test and lower viscosities reached by the base oil. The commercial oil is shown to have both a higher FMEP at a given viscosity and a higher average FMEP than the commercial oil without a friction and wear reducing additive. The increase in friction for the oil without a friction and wear reduction additive indicates that the operational regime of the engine may be out of the bounds of the optimal regime for the additive or that the additive is more optimized for wear reduction. Results show that it is feasible to observe small differences in FMEP between lubricating oil formulations using a small, single-cylinder motored engine.

  7. 76 FR 647 - Energy Conservation Program: Test Procedures for Electric Motors and Small Electric Motors

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-05

    ... FR 54114. After determining that energy conservation standards for small electric motors would be... adopting test procedures for measuring the energy efficiency of small electric motors. 74 FR 32059. However... Energy 10 CFR Part 431 Energy Conservation Program: Test Procedures for Electric Motors and...

  8. Electrohydrodynamic Pumping: Flow Near a Cylinder in a Uniform Electric Field

    NASA Astrophysics Data System (ADS)

    Saville, D. A.; McBride, S. E.

    1999-11-01

    Liquid near an electrode can be set into motion through the action of an electric field on free charge. If a unidirectional flow ensues, the arrangement constitutes an electrohydrodynamic pump. Experimental work on a cylindrical electrode arrangement identified thin polarization layers with a non-uniform conductivity near the electrodes. An idealized configuration was studied theoretically with a single cylindrical electrode placed in a uniform field. Since the flow is slow, it can be described by solutions of the Stokes equations with an electrical body force. According to our calculations, electrical forces within the polarization layers produce a pumping action that manifests itself as a uniform flow ‘at infinity.’ In our configuration, solutions of the Stokes equations are uniformly valid and the singular behavior found in other two-dimensional Stokes flows is absent. In addition, there is an attached eddy on the upstream side of the electrode. The qualitative features of the predicted flow are consistent with the experimental results, suggesting that the concept of a polarization layer is a useful stratagem in describing the pumping process.

  9. Electrochemical reclamation of silver from silver-plating wastewater using static cylinder electrodes and a pulsed electric field.

    PubMed

    Su, Yuan-Bo; Li, Qing-Biao; Wang, Yuan-Peng; Wang, Hai-Tao; Huang, Jia-le; Yang, Xin

    2009-10-30

    Silver was reclaimed from silver-plating wastewater by using a pulsed electric field (PEF) combined with static cylinder electrodes (SCE). The conditions that produced the maximal silver recovery rate (RR(Ag)) (99%) were as follows: average retention time of 10 min, interelectrode gap of 50mm, solution pH of 9.0, temperature of 45 degrees C, initial Ag(I) concentration of 1000 mg L(-1), PEF pulse frequency of 1200 Hz, current density of 5.0 A m(-2) and a pulse duty cycle of 60%. Compared with the conventional direct current (DC) technology, the PEF process exhibited improvements in the silver recovery rate (RR(Ag)), total energy consumption (TEC) and physical properties of the silver deposits, especially for low Ag(I) concentrations, for example, from 500 to 1000 mg L(-1). For an initial Ag(I) concentration of 500 mg L(-1), the PEF process produced an RR(Ag) of up to 99%, and the TEC was 4.56 kWh (kg Ag)(-1). In comparison, the RR(Ag) and TEC were 90% and 5.66 kWh (kg Ag)(-1), respectively, in the DC process. The results of SEM observation and XRD analysis indicated that the silver deposits formed by the PEF process were smaller, denser, and of a higher purity than those produced by the DC process. Therefore, the presented method was effective for reclaiming silver from silver-plating wastewater. PMID:19545945

  10. Small geothermal electric systems for remote powering

    SciTech Connect

    Entingh, Daniel J.; Easwaran, Eyob.; McLarty, Lynn

    1994-08-08

    This report describes conditions and costs at which quite small (100 to 1,000 kilowatt) geothermal systems could be used for off-grid powering at remote locations. This is a first step in a larger process of determining locations and conditions at which markets for such systems could be developed. The results suggest that small geothermal systems offer substantial economic and environmental advantages for powering off-grid towns and villages. Geothermal power is most likely to be economic if the system size is 300 kW or greater, down to reservoir temperatures of 100{degree}C. For system sizes smaller than 300 kW, the economics can be favorable if the reservoir temperature is about 120{degree}C or above. Important markets include sites remote from grids in many developing and developed countries. Estimates of geothermal resources in many developing countries are shown.

  11. Dynamic MRI of small electrical activity.

    PubMed

    Song, Allen W; Truong, Trong-Kha; Woldorff, Marty

    2009-01-01

    Neuroscience methods entailing in vivo measurements of brain activity have greatly contributed to our understanding of brain function for the past decades, from the invasive early studies in animals using single-cell electrical recordings, to the noninvasive techniques in humans of scalp-recorded electroencephalography (EEG) and magnetoencephalography (MEG), positron emission tomography (PET), and, most recently, blood oxygenation level-dependent (BOLD) functional magnetic resonance imaging (fMRI). A central objective of these techniques is to measure neuronal activities with high spatial and temporal resolution. Each of these methods, however, has substantial limitations in this regard. Single-cell recording is invasive and only typically records cellular activity in a single location; EEG/MEG cannot generally provide accurate and unambiguous delineations of neuronal activation spatially; and the most sophisticated BOLD-based fMRI methods are still fundamentally limited by their dependence on the very slow hemodynamic responses upon which they are based. Even the latest neuroimaging methodology (e.g., multimodal EEG/fMRI) does not yet unambiguously provide accurate localization of neuronal activation spatially and temporally. There is hence a need to further develop noninvasive imaging methods that can directly image neuroelectric activity and thus truly achieve a high temporal resolution and spatial specificity in humans. Here, we discuss the theory, implementation, and potential utility of an MRI technique termed Lorentz effect imaging (LEI) that can detect spatially incoherent yet temporally synchronized, minute electrical activities in the neural amplitude range (microamperes) when they occur in a strong magnetic field. Moreover, we demonstrate with our preliminary results in phantoms and in vivo, the feasibility of imaging such activities with a temporal resolution on the order of milliseconds.

  12. Electric utility growth: The small business connection

    SciTech Connect

    Stafford, J.R. )

    1990-08-02

    In today's competitive environment utilities must seek new strategies to insure future growth. Economic development is but one of many utility strategies being implemented today. Traditionally, most utility economic development efforts involve the recruitment of targeted industries. This recruitment strategy involves the identification of attractive industries and companies, and subsequent marketing efforts to encourage company relocation or expansion in the utility's service territory. This strategy is the most practiced by utilities, yet ironically it has been judged as relatively ineffective. The purpose of this study is to evaluate the merits of utilities refocusing their economic development efforts on a new strategy currently employed by state and local growth organizations and oriented toward business retention and expansion rather than industrial targeting and recruitment. Many utilities have retention/expansion strategies, but target them at their largest industrial customers. The focus of this article is on the value of small business retention/expansion activities and the feasibility of implementing a successful plan.

  13. Determination of the 235U Mass and Enrichment within Small UF6 Cylinders via a Neutron Coincidence Well Counting System

    SciTech Connect

    McElroy, Robert Dennis; Croft, Dr. Stephen; Young, Brian M; Venkataraman, Ram

    2011-01-01

    The construction of three new uranium enrichment facilities in the United States has sparked renewed interest in the development and enhancement of methods to determine the enrichment and fissile mass content of UF6 cylinders. We describe the design and examine the expected performance of a UF6 bottle counter developed for the assay of Type 5A cylinders. The counter, as designed and subsequently constructed, is a tall passive neutron well counter with a clam-shell configuration and graphite end plugs operated in fast neutron mode. Factory performance against expectation is described. The relatively high detection efficiency and effectively 4 detection geometry provide a near-ideal measurement configuration, making the UF6 bottle counter a valuable tool for the evaluation of the neutron coincidence approach to UF6 cylinder assay. The impacts of non-uniform filling, voids, enrichment, and mixed enrichments are examined

  14. The Effect of Small Bubbles on Resistance Reduction of Water Flow in Co-axial Cylinders with an Inner Rotating Cylinder

    NASA Astrophysics Data System (ADS)

    Maryami, R.; Farahat, S.; Poor, M. J.

    2015-04-01

    Drawing on effective experiments and measurement technology, the present study seeks to discuss the interaction between liquid turbulent boundary layer and a crowded group of small bubbles. Experiments are carried out using a circulating water Couette-Taylor system especially designed for small bubble experiments. Couette-Taylor system has a detailed test section, which allows measuring the effect of persistent head resistance reduction caused by small bubbles in the streamwise direction. Pressure difference is measured using sensors which are mounted at the bottom and top of the system to calculate head resistance. Pressure difference and bubble behavior are measured as a function of rotational Reynolds number up to 67.8 × 103. Small bubbles are injected constantly into annulus gap using two injectors installed at the bottom of the system and they are lifted through an array of vertical cells. Water is used to avoid uncertain interfacial property of bubbles and to produce relatively mono-sized bubble distributions. The bubble sizes range approximately from 0.9 to 1.4 mm, which are identified by the image processing method. The results suggest that head resistance is decreased after the injection of small bubble in all rotational Reynolds number under study, changing from 7,000 to 67.8 × 103. Moreover, void fraction is increased from 0 to 10.33 %. A head resistance reduction greater than 75 % was achieved in this study after the maximum measured volume of air fraction was injected into fluid flow while bubbles were distinct without making any gas layer.

  15. Small space station electrical power system design concepts

    NASA Technical Reports Server (NTRS)

    Jones, G. M.; Mercer, L. N.

    1976-01-01

    A small manned facility, i.e., a small space station, placed in earth orbit by the Shuttle transportation system would be a viable, cost effective addition to the basic Shuttle system to provide many opportunities for R&D programs, particularly in the area of earth applications. The small space station would have many similarities with Skylab. This paper presents design concepts for an electrical power system (EPS) for the small space station based on Skylab experience, in-house work at Marshall Space Flight Center, SEPS (Solar Electric Propulsion Stage) solar array development studies, and other studies sponsored by MSFC. The proposed EPS would be a solar array/secondary battery system. Design concepts expressed are based on maximizing system efficiency and five year operational reliability. Cost, weight, volume, and complexity considerations are inherent in the concepts presented. A small space station EPS based on these concepts would be highly efficient, reliable, and relatively inexpensive.

  16. Stability of Non-Neutral Plasma Cylinder Consisting of Magnetized Cold Electrons and of Small Density Fraction of Ions Born at Rest: Non-Local Analysis

    SciTech Connect

    Yeliseyev, Y. N.

    2009-03-30

    The non-local stability problem of the plasma cylinder, filled with 'cold' magnetized rigidly rotating electrons, and a small density fraction of ions, is solved. The ions are supposed to be born at rest by ionization of background gas. The study is based on the kinetic description of ions. The equilibrium distribution function, taking into account the peculiarity of ions birth, is used. The radial electric field is caused by space charge of non-neutral plasma. The dispersion equation for plasma eigen frequencies is obtained analytically. It is valid within the total admissible range of values of electric and magnetic fields. Normalized eigen frequencies {omega}'/{omega}{sub i} are calculated for the basic azimuth mode m = 1({omega}' {omega}-m{omega}{sub i}{sup +}, {omega}{sub +} = (-{omega}{sub ci}+{omega}{sub i})/2, {omega}{sub i} ({omega}{sub ci}{sup 2}-4eE{sub r}/m{sub i}r){sup 1/2} is called the 'modified' ion cyclotron (MIC) frequency), for the density fraction of ions of atomic nitrogen f N{sub i}/n{sub e} = 0,01 and are presented in graphic form versus parameter 2{omega}{sub pe}{sup 2}/{omega}{sub ce}{sup 2}. The spectra of oscillations {omega}'/{omega}{sub i} consist of the family of electron Trivel-piece--Gould (TG) modes and of the families of MIC modes. The frequencies of MIC modes are located in a small vicinity of harmonics of the MIC frequency {omega}{sub i} above and below the harmonic. The TG modes in non-neutral plasma fall in the region of MIC frequencies {omega}{sub i} and interact strongly with MIC modes. The slow TG modes become unstable near the crossings with non-negative harmonics of MIC frequencies. The instabilities have a resonant character. The lowest radial TG mode has a maximum growth rate at crossing with a zero harmonic of {omega}{sub i} ((Im {omega}'/{omega}{sub i}){sub max}{approx_equal}0,074). The growth rates of MIC modes are much lower ((Im {omega}'/{omega}{sub i}){sub max} < or approx. 0,002). Their instability has a threshold

  17. Stability of Non-Neutral Plasma Cylinder Consisting of Magnetized Cold Electrons and of Small Density Fraction of Ions Born at Rest: Non-Local Analysis

    NASA Astrophysics Data System (ADS)

    Yeliseyev, Y. N.

    2009-03-01

    The non-local stability problem of the plasma cylinder, filled with "cold" magnetized rigidly rotating electrons, and a small density fraction of ions, is solved. The ions are supposed to be born at rest by ionization of background gas. The study is based on the kinetic description of ions. The equilibrium distribution function, taking into account the peculiarity of ions birth, is used. The radial electric field is caused by space charge of non-neutral plasma. The dispersion equation for plasma eigen frequencies is obtained analytically. It is valid within the total admissible range of values of electric and magnetic fields. Normalized eigen frequencies ω'/Ωi are calculated for the basic azimuth mode m = 1 (ω' = ω-mωi+, ω+ = (-ωci+Ωi)/2, Ωi = (ωci2-4eEr/mir)1/2 is called the "modified" ion cyclotron (MIC) frequency), for the density fraction of ions of atomic nitrogen f = Ni/ne = 0,01 and are presented in graphic form versus parameter 2ωpe2/ωce2. The spectra of oscillations ω'/Ωi consist of the family of electron Trivel-piece—Gould (TG) modes and of the families of MIC modes. The frequencies of MIC modes are located in a small vicinity of harmonics of the MIC frequency Ωi above and below the harmonic. The TG modes in non-neutral plasma fall in the region of MIC frequencies Ωi and interact strongly with MIC modes. The slow TG modes become unstable near the crossings with non-negative harmonics of MIC frequencies. The instabilities have a resonant character. The lowest radial TG mode has a maximum growth rate at crossing with a zero harmonic of Ωi ((Im ω'/Ωi)max≈0,074). The growth rates of MIC modes are much lower ((Im ω'/Ωi)max≲0,002). Their instability has a threshold character. The instabilities of TG and MIC modes take place mainly at the values of parameter 2ωpe2/ωce2, corresponding to strong radial electric fields (ωci2≪|eEr/mir|), in which the ions are unmagnetized. The oscillations of small amplitude are seen on some frequency

  18. Small Wind Electric Systems: An Indiana Consumer's Guide

    SciTech Connect

    2009-01-18

    This guide provides consumers with information to help them determine whether a small wind electric system can provide all or a portion of the energy they need for their home or business based on their wind resource, energy needs, and economics.

  19. Small Wind Electric Systems: A Rhode Island Consumer's Guide

    SciTech Connect

    2003-06-01

    This guide provides consumers with information to help them determine whether a small wind electric system can provide all or a portion of the energy they need for their home or business based on their wind resource, energy needs, and economics.

  20. Small Wind Electric Systems: A Vermont Consumer's Guide

    SciTech Connect

    2004-10-01

    This guide provides consumers with information to help them determine whether a small wind electric system can provide all or a portion of the energy they need for their home or business based on their wind resource, energy needs, and economics.

  1. Small Wind Electric Systems: An Oklahoma Consumer's Guide

    SciTech Connect

    2009-01-18

    This guide provides consumers with information to help them determine whether a small wind electric system can provide all or a portion of the energy they need for their home or business based on their wind resource, energy needs, and economics.

  2. Small Wind Electric Systems: A Nevada Consumer's Guide

    SciTech Connect

    2009-01-18

    This guide provides consumers with information to help them determine whether a small wind electric system can provide all or a portion of the energy they need for their home or business based on their wind resource, energy needs, and economics.

  3. Small Wind Electric Systems: A Nebraska Consumer's Guide

    SciTech Connect

    2009-01-18

    This guide provides consumers with information to help them determine whether a small wind electric system can provide all or a portion of the energy they need for their home or business based on their wind resource, energy needs, and economics.

  4. Small Wind Electric Systems: A Missouri Consumer's Guide

    SciTech Connect

    2009-01-18

    This guide provides consumers with information to help them determine whether a small wind electric system can provide all or a portion of the energy they need for their home or business based on their wind resource, energy needs, and economics.

  5. Small Wind Electric Systems: A Hawaii Consumer's Guide

    SciTech Connect

    2009-01-18

    This guide provides consumers with information to help them determine whether a small wind electric system can provide all or a portion of the energy they need for their home or business based on their wind resource, energy needs, and economics.

  6. Small Wind Electric Systems: A Utah Consumer's Guide

    SciTech Connect

    2009-01-18

    This guide provides consumers with information to help them determine whether a small wind electric system can provide all or a portion of the energy they need for their home or business based on their wind resource, energy needs, and economics.

  7. Small Wind Electric Systems: A New Mexico Consumer's Guide

    SciTech Connect

    2004-08-01

    This guide provides consumers with information to help them determine whether a small wind electric system can provide all or a portion of the energy they need for their home or business based on their wind resource, energy needs, and economics.

  8. Small Wind Electric Systems: A Michigan Consumer's Guide

    SciTech Connect

    2009-01-18

    This guide provides consumers with information to help them determine whether a small wind electric system can provide all or a portion of the energy they need for their home or business based on their wind resource, energy needs, and economics.

  9. Small Wind Electric Systems: A Colorado Consumer's Guide

    SciTech Connect

    Not Available

    2006-12-01

    Small Wind Electric Systems: A Colorado Consumer's Guide provides consumers with information to help them determine whether a small wind electric system can provide all or a portion of the energy they need for their home or business based on their wind resource, energy needs, and economics. Topics include how to make a home more energy efficient, how to choose the correct turbine size, the parts of a wind electric system, how to determine whether enough wind resource exists, how to choose the best site for a turbine, how to connect a system to the utility grid, and whether it's possible to become independent of the utility grid using wind energy. In addition, the cover of the guide contains a list of contacts for more information.

  10. Small Wind Electric Systems: A Montana Consumer's Guide (Revised)

    SciTech Connect

    Not Available

    2006-04-01

    Small Wind Electric Systems: A Montana Consumer's Guide provides consumers with information to help them determine whether a small wind electric system can provide all or a portion of the energy they need for their home or business based on their wind resource, energy needs, and economics. Topics include how to make a home more energy efficient, how to choose the correct turbine size, the parts of a wind electric system, how to determine whether enough wind resource exists, how to choose the best site for a turbine, how to connect a system to the utility grid, and whether it's possible to become independent of the utility grid using wind energy. In addition, the cover of the guide contains a list of contacts for more information.

  11. Small Wind Electric Systems: A Washington Consumer's Guide

    SciTech Connect

    Not Available

    2007-08-01

    Small Wind Electric Systems: A Washington Consumer's Guide provides consumers with information to help them determine whether a small wind electric system can provide all or a portion of the energy they need for their home or business based on their wind resource, energy needs, and economics. Topics include how to make a home more energy efficient, how to choose the correct turbine size, the parts of a wind electric system, how to determine whether enough wind resource exists, how to choose the best site for a turbine, how to connect a system to the utility grid, and whether it's possible to become independent of the utility grid using wind energy. In addition, the cover of the guide contains a list of contacts for more information.

  12. Small Wind Electric Systems: A Kansas Consumer's Guide

    SciTech Connect

    Not Available

    2007-08-01

    Small Wind Electric Systems: A Kansas Consumer's Guide provides consumers with information to help them determine whether a small wind electric system can provide all or a portion of the energy they need for their home or business based on their wind resource, energy needs, and their economics. Topics discussed in the guide include how to make a home more energy efficient, how to choose the correct turbine size, the parts of a wind electric system, how to determine whether enough wind resource exists, how to choose the best site for a turbine, how to connect a system to the utility grid, and whether it's possible to become independent of the utility grid using wind energy. In addition, the cover of the guide contains a list of contacts for more information.

  13. Small Wind Electric Systems: A U.S. Consumer's Guide

    SciTech Connect

    Not Available

    2007-08-01

    Small Wind Electric Systems: A U.S. Consumer's Guide provides consumers with information to help them determine whether a small wind electric system can provide all or a portion of the energy they need for their home or business based on their wind resource, energy needs, and their economics. Topics discussed in the guide include how to make a home more energy efficient, how to choose the correct turbine size, the parts of a wind electric system, how to determine whether enough wind resource exists, how to choose the best site for a turbine, how to connect a system to the utility grid, and whether it's possible to become independent of the utility grid using wind energy. In addition, the cover of the guide contains a list of contacts for more information.

  14. Small Wind Electric Systems: An Ohio Consumer's Guide

    SciTech Connect

    Not Available

    2007-08-01

    Small Wind Electric Systems: An Ohio Consumer's Guide provides consumers with information to help them determine whether a small wind electric system can provide all or a portion of the energy they need for their home or business based on their wind resource, energy needs, and their economics. Topics discussed in the guide include how to make a home more energy efficient, how to choose the correct turbine size, the parts of a wind electric system, how to determine whether enough wind resource exists, how to choose the best site for a turbine, how to connect a system to the utility grid, and whether it's possible to become independent of the utility grid using wind energy. In addition, the cover of the guide contains a list of contacts for more information.

  15. Small Wind Electric Systems: A Maine Consumer's Guide

    SciTech Connect

    Not Available

    2007-08-01

    Small Wind Electric Systems: A Maine Consumer's Guide provides consumers with information to help them determine whether a small wind electric system can provide all or a portion of the energy they need for their home or business based on their wind resource, energy needs, and their economics. Topics discussed in the guide include how to make a home more energy efficient, how to choose the correct turbine size, the parts of a wind electric system, how to determine whether enough wind resource exists, how to choose the best site for a turbine, how to connect a system to the utility grid, and whether it's possible to become independent of the utility grid using wind energy. In addition, the cover of the guide contains a list of contacts for more information.

  16. Small Wind Electric Systems: A Pennsylvania Consumer's Guide

    SciTech Connect

    Not Available

    2007-08-01

    Small Wind Electric Systems: A Pennsylvania Consumer's Guide provides consumers with information to help them determine whether a small wind electric system can provide all or a portion of the energy they need for their home or business based on their wind resource, energy needs, and their economics. Topics discussed in the guide include how to make a home more energy efficient, how to choose the correct turbine size, the parts of a wind electric system, how to determine whether enough wind resource exists, how to choose the best site for a turbine, how to connect a system to the utility grid, and whether it's possible to become independent of the utility grid using wind energy. In addition, the cover of the guide contains a list of contacts for more information.

  17. Small Wind Electric Systems: An Oklahoma Consumer's Guide

    SciTech Connect

    Not Available

    2007-08-01

    Small Wind Electric Systems: An Oklahoma Consumer's Guide provides consumers with information to help them determine whether a small wind electric system can provide all or a portion of the energy they need for their home or business based on their wind resource, energy needs, and economics. Topics include how to make a home more energy efficient, how to choose the correct turbine size, the parts of a wind electric system, how to determine whether enough wind resource exists, how to choose the best site for a turbine, how to connect a system to the utility grid, and whether it's possible to become independent of the utility grid using wind energy. In addition, the cover of the guide contains a list of contacts for more information.

  18. Small Wind Electric Systems: A South Dakota Consumer's Guide

    SciTech Connect

    Not Available

    2007-04-01

    Small Wind Electric Systems: A South Dakota Consumer's Guide provides consumers with information to help them determine whether a small wind electric system can provide all or a portion of the energy they need for their home or business based on their wind resource, energy needs, and economics. Topics include how to make a home more energy efficient, how to choose the correct turbine size, the parts of a wind electric system, how to determine whether enough wind resource exists, how to choose the best site for a turbine, how to connect a system to the utility grid, and whether it's possible to become independent of the utility grid using wind energy. In addition, the cover of the guide contains a list of contacts for more information.

  19. Small Wind Electric Systems: A Minnesota Consumer's Guide

    SciTech Connect

    Not Available

    2007-04-01

    Small Wind Electric Systems: A Minnesota Consumer's Guide provides consumers with information to help them determine whether a small wind electric system can provide all or a portion of the energy they need for their home or business based on their wind resource, energy needs, and economics. Topics include how to make a home more energy efficient, how to choose the correct turbine size, the parts of a wind electric system, how to determine whether enough wind resource exists, how to choose the best site for a turbine, how to connect a system to the utility grid, and whether it's possible to become independent of the utility grid using wind energy. In addition, the cover of the guide contains a list of contacts for more information.

  20. Small Wind Electric Systems: A Maryland Consumer's Guide

    SciTech Connect

    Not Available

    2007-01-01

    Small Wind Electric Systems: A Maryland Consumer's Guide provides consumers with information to help them determine whether a small wind electric system can provide all or a portion of the energy they need for their home or business based on their wind resource, energy needs, and economics. Topics include how to make a home more energy efficient, how to choose the correct turbine size, the parts of a wind electric system, how to determine whether enough wind resource exists, how to choose the best site for a turbine, how to connect a system to the utility grid, and whether it's possible to become independent of the utility grid using wind energy. In addition, the cover of the guide contains a list of contacts for more information.

  1. Small Wind Electric Systems: An Oregon Consumer's Guide

    SciTech Connect

    Not Available

    2007-08-01

    Small Wind Electric Systems: An Oregon Consumer's Guide provides consumers with information to help them determine whether a small wind electric system can provide all or a portion of the energy they need for their home or business based on their wind resource, energy needs, and economics. Topics include how to make a home more energy efficient, how to choose the correct turbine size, the parts of a wind electric system, how to determine whether enough wind resource exists, how to choose the best site for a turbine, how to connect a system to the utility grid, and whether it's possible to become independent of the utility grid using wind energy. In addition, the cover of the guide contains a list of contacts for more information.

  2. Small Wind Electric Systems: A Hawaii Consumer's Guide

    SciTech Connect

    Not Available

    2007-08-01

    Small Wind Electric Systems: A Hawaii Consumer's Guide provides consumers with information to help them determine whether a small wind electric system can provide all or a portion of the energy they need for their home or business based on their wind resource, energy needs, and their economics. Topics discussed in the guide include how to make a home more energy efficient, how to choose the correct turbine size, the parts of a wind electric system, how to determine whether enough wind resource exists, how to choose the best site for a turbine, how to connect a system to the utility grid, and whether it's possible to become independent of the utility grid using wind energy. In addition, the cover of the guide contains a list of contacts for more information.

  3. Small Wind Electric Systems: A Maryland Consumer's Guide (Revised)

    SciTech Connect

    Not Available

    2009-08-01

    Small Wind Electric Systems: A Maryland Consumer's Guide provides consumers with information to help them determine whether a small wind electric system can provide all or a portion of the energy they need for their home or business based on their wind resource, energy needs, and their economics. Topics discussed in the guide include how to make a home more energy efficient, how to choose the correct turbine size, the parts of a wind electric system, how to determine whether enough wind resource exists, how to choose the best site for a turbine, how to connect a system to the utility grid, and whether it's possible to become independent of the utility grid using wind energy. In addition, the cover of the guide contains a regional wind resource map and a list of incentives and contacts for more information.

  4. Small Wind Electric Systems: A Utah Consumer's Guide

    SciTech Connect

    Not Available

    2007-08-01

    Small Wind Electric Systems: A Utah Consumer's Guide provides Utah consumers with information to help them determine whether a small wind electric system can provide all or a portion of the energy they need for their home or business based on their wind resource, energy needs, and their economics. Topics discussed in the guide include how to make a home more energy efficient, how to choose the correct turbine size, the parts of a wind electric system, how to determine whether enough wind resource exists, how to choose the best site for a turbine, how to connect a system to the utility grid, and whether it's possible to become independent of the utility grid using wind energy. In addition, the cover of the guide contains a list of contacts for more information.

  5. Small Wind Electric Systems: An Alaska Consumer's Guide

    SciTech Connect

    Not Available

    2007-04-01

    Small Wind Electric Systems: An Alaska Consumer's Guide provides consumers with information to help them determine whether a small wind electric system can provide all or a portion of the energy they need for their home or business based on their wind resource, energy needs, and economics. Topics include how to make a home more energy efficient, how to choose the correct turbine size, the parts of a wind electric system, how to determine whether enough wind resource exists, how to choose the best site for a turbine, how to connect a system to the utility grid, and whether it's possible to become independent of the utility grid using wind energy. In addition, the cover of the guide contains a list of contacts for more information.

  6. Small Wind Electric Systems: A Vermont Consumer's Guide

    SciTech Connect

    Not Available

    2007-04-01

    Small Wind Electric Systems: A Vermont Consumer's Guide provides consumers with information to help them determine whether a small wind electric system can provide all or a portion of the energy they need for their home or business based on their wind resource, energy needs, and economics. Topics include how to make a home more energy efficient, how to choose the correct turbine size, the parts of a wind electric system, how to determine whether enough wind resource exists, how to choose the best site for a turbine, how to connect a system to the utility grid, and whether it's possible to become independent of the utility grid using wind energy. In addition, the cover of the guide contains a list of contacts for more information.

  7. Small Wind Electric Systems: A Montana Consumer's Guide

    SciTech Connect

    Not Available

    2007-08-01

    Small Wind Electric Systems: A Montana Consumer's Guide provides consumers with information to help them determine whether a small wind electric system can provide all or a portion of the energy they need for their home or business based on their wind resource, energy needs, and economics. Topics include how to make a home more energy efficient, how to choose the correct turbine size, the parts of a wind electric system, how to determine whether enough wind resource exists, how to choose the best site for a turbine, how to connect a system to the utility grid, and whether it's possible to become independent of the utility grid using wind energy. In addition, the cover of the guide contains a list of contacts for more information.

  8. Small Wind Electric Systems: A Michigan Consumer's Guide (revised)

    SciTech Connect

    Not Available

    2007-01-01

    Small Wind Electric Systems: A Michigan Consumer's Guide provides consumers with information to help them determine whether a small wind electric system can provide all or a portion of the energy they need for their home or business based on their wind resource, energy needs, and economics. Topics include how to make a home more energy efficient, how to choose the correct turbine size, the parts of a wind electric system, how to determine whether enough wind resource exists, how to choose the best site for a turbine, how to connect a system to the utility grid, and whether it's possible to become independent of the utility grid using wind energy. In addition, the cover of the guide contains a list of contacts for more information.

  9. Small Wind Electric Systems: A North Dakota Consumer's Guide

    SciTech Connect

    Not Available

    2007-04-01

    Small Wind Electric Systems: A North Dakota Consumer's Guide provides consumers with information to help them determine whether a small wind electric system can provide all or a portion of the energy they need for their home or business based on their wind resource, energy needs, and economics. Topics include how to make a home more energy efficient, how to choose the correct turbine size, the parts of a wind electric system, how to determine whether enough wind resource exists, how to choose the best site for a turbine, how to connect a system to the utility grid, and whether it's possible to become independent of the utility grid using wind energy. In addition, the cover of the guide contains a list of contacts for more information.

  10. Small Wind Electric Systems: An Illinois Consumer's Guide

    SciTech Connect

    Not Available

    2007-04-01

    Small Wind Electric Systems: An Illinois Consumer's Guide provides consumers with information to help them determine whether a small wind electric system can provide all or a portion of the energy they need for their home or business based on their wind resource, energy needs, and economics. Topics include how to make a home more energy efficient, how to choose the correct turbine size, the parts of a wind electric system, how to determine whether enough wind resource exists, how to choose the best site for a turbine, how to connect a system to the utility grid, and whether it's possible to become independent of the utility grid using wind energy. In addition, the cover of the guide contains a list of contacts for more information.

  11. Small Wind Electric Systems: A Nebraska Consumer's Guide

    SciTech Connect

    Not Available

    2007-12-01

    Small Wind Electric Systems: A Nebraska Consumer's Guide provides consumers with information to help them determine whether a small wind electric system can provide all or a portion of the energy they need for their home or business based on their wind resource, energy needs, and their economics. Topics discussed in the guide include how to make a home more energy efficient, how to choose the correct turbine size, the parts of a wind electric system, how to determine whether enough wind resource exists, how to choose the best site for a turbine, how to connect a system to the utility grid, and whether it's possible to become independent of the utility grid using wind energy. In addition, the cover of the guide contains a list of contacts for more information.

  12. Small Wind Electric Systems: An Oregon Consumer's Guide

    SciTech Connect

    Not Available

    2002-05-01

    Small Wind Electric Systems An Oregon Consumer's Guide provides consumers with enough information to help them determine if a small wind electric system can provide all or a portion of the energy they need for their home or business based on their wind resource, energy needs, and their economics. Topics discussed in the guide include: how to make your home more energy efficient, how to choose the right size turbine, the parts of a wind electric system, determining if there is enough wind resource on your site, choosing the best site for your turbine, connecting your system to the utility grid, and if it's possible to become independent of the utility grid using wind energy. In addition, the Oregon guide provides state specific information that includes and state wind resource map, state incentives, and state contacts for more information.

  13. Small Wind Electric Systems: An Oregon Consumer's Guide

    SciTech Connect

    Not Available

    2005-03-01

    Small Wind Electric Systems: An Oregon Consumer's Guide provides consumers with information to help them determine whether a small wind electric system can provide all or a portion of the energy they need for their home or business based on their wind resource, energy needs, and their economics. Topics discussed in the guide include how to make a home more energy efficient, how to choose the correct turbine size, the parts of a wind electric system, how to determine whether enough wind resource exists, how to choose the best site for a turbine, how to connect a system to the utility grid, and whether it's possible to become independent of the utility grid using wind energy. In addition, the cover of the guide contains a regional wind resource map and a list of incentives and contacts for more information.

  14. Small Wind Electric Systems: A Virginia Consumer's Guide

    SciTech Connect

    Not Available

    2007-01-01

    Small Wind Electric Systems: A Virginia Consumer's Guide provides consumers with information to help them determine whether a small wind electric system can provide all or a portion of the energy they need for their home or business based on their wind resource, energy needs, and economics. Topics include how to make a home more energy efficient, how to choose the correct turbine size, the parts of a wind electric system, how to determine whether enough wind resource exists, how to choose the best site for a turbine, how to connect a system to the utility grid, and whether it's possible to become independent of the utility grid using wind energy. In addition, the cover of the guide contains a list of contacts for more information.

  15. Diffusion from solid cylinders

    SciTech Connect

    Nestor, C.W. Jr.

    1980-01-01

    The problem considered is the diffusion of material from a solid cylinder initially containng a uniform concentration and immersed in a well-stirred bath which maintains the external concentration at zero. The Fourier-Bessel series form of the fraction of the original material removed from the cylinder as a function of time converges very slowly for small time. An alternate form was obtained, which converges reasonably rapidly for small time. The convergence acceleration method of P. Wynn was also used to provide an efficient method for computation. Numerical examples and program listings are included.

  16. Normal and abnormal electrical propagation in the small intestine.

    PubMed

    Lammers, W J E P

    2015-02-01

    As in other muscular organs, small intestinal motility is determined to a large degree by the electrical activities that occur in the smooth muscle layers of the small intestine. In recent decades, the interstitial cells of Cajal, located in the myenteric plexus, have been shown to be responsible for the generation and propagation of the electrical impulse: the slow wave. It was also known that the slow waves as such do not cause contraction, but that the action potentials ('spikes') that are generated by the slow waves are responsible for the contractions. Recording from large number of extracellular electrodes simultaneously is one method to determine origin and pattern of propagation of these electrical signals. This review reports the characteristics of slow wave propagation through the intestinal tube, the occurrence of propagation blocks along its length, which explains the well-known decrease in frequency, and the specific propagation pattern of the spikes that follow the slow waves. But the value of high-resolution mapping is highest in discovering and analysing mechanisms of arrhythmias in the gut. Most recently, circus movements (also called 're-entries') have been described in the small intestine in several species. Moreover, several types of re-entries have now been described, some similar to what may occur in the heart, such as functional re-entries, but others more unique to the small intestine, such as circumferential re-entry. These findings seem to suggest the possibilities of hitherto unknown pathologies that may be present in the small intestine.

  17. Anaesthesia gas supply: gas cylinders.

    PubMed

    Srivastava, Uma

    2013-09-01

    Invention of oxygen cylinder was one of the most important developments in the field of medical practice. Oxygen and other gases were compressed and stored at high pressure in seamless containers constructed from hand-forged steel in1880. Materials technology has continued to evolve and now medical gas cylinders are generally made of steel alloys or aluminum. The filling pressure as well as capacity has increased considerably while at the same time the weight of cylinders has reduced. Today oxygen cylinder of equivalent size holds a third more oxygen but weighs about 20 kg less. The cylinders are of varying sizes and are color coded. They are tested at regular intervals by the manufacturer using hydraulic, impact, and tensile tests. The top end of the cylinder is fitted with a valve with a variety of number and markings stamped on it. Common valve types include: Pin index valve, bull nose, hand wheel and integral valve. The type of valve varies with cylinder size. Small cylinders have a pin index valve while large have a bull nose type. Safety features in the cylinder are: Color coding, pin index, pressure relief device, Bodok seal, and label attached etc., Safety rules and guidelines must be followed during storage, installation and use of cylinders to ensure safety of patients, hospital personnel and the environment.

  18. Anaesthesia Gas Supply: Gas Cylinders

    PubMed Central

    Srivastava, Uma

    2013-01-01

    Invention of oxygen cylinder was one of the most important developments in the field of medical practice. Oxygen and other gases were compressed and stored at high pressure in seamless containers constructed from hand-forged steel in1880. Materials technology has continued to evolve and now medical gas cylinders are generally made of steel alloys or aluminum. The filling pressure as well as capacity has increased considerably while at the same time the weight of cylinders has reduced. Today oxygen cylinder of equivalent size holds a third more oxygen but weighs about 20 kg less. The cylinders are of varying sizes and are color coded. They are tested at regular intervals by the manufacturer using hydraulic, impact, and tensile tests. The top end of the cylinder is fitted with a valve with a variety of number and markings stamped on it. Common valve types include: Pin index valve, bull nose, hand wheel and integral valve. The type of valve varies with cylinder size. Small cylinders have a pin index valve while large have a bull nose type. Safety features in the cylinder are: Color coding, pin index, pressure relief device, Bodok seal, and label attached etc., Safety rules and guidelines must be followed during storage, installation and use of cylinders to ensure safety of patients, hospital personnel and the environment. PMID:24249883

  19. Small Wind Electric Systems: A U.S. Consumer's Guide

    SciTech Connect

    2007-08-01

    The handbook provides consumers with information to help them determine whether a small wind electric system can provide all or a portion of the energy they need for their home or business based on their wind resource, energy needs, and their economics. Topics discussed in the guide include how to make a home more energy efficient, how to choose the correct turbine size, the parts of a wind electric system, how to determine whether enough wind resource exists, how to choose the best site for a turbine, how to connect a system to the utility grid, and whether it's possible to become independent of the utility grid using wind energy.

  20. Natural convective heat transfer from square cylinder

    NASA Astrophysics Data System (ADS)

    Novomestský, Marcel; Smatanová, Helena; Kapjor, Andrej

    2016-06-01

    This article is concerned with natural convective heat transfer from square cylinder mounted on a plane adiabatic base, the cylinders having an exposed cylinder surface according to different horizontal angle. The cylinder receives heat from a radiating heater which results in a buoyant flow. There are many industrial applications, including refrigeration, ventilation and the cooling of electrical components, for which the present study may be applicable

  1. Small solar thermal electric power plants with early commercial potential

    NASA Technical Reports Server (NTRS)

    Jones, H. E.; Bisantz, D. J.; Clayton, R. N.; Heiges, H. H.; Ku, A. C.

    1979-01-01

    Cost-effective small solar thermal electric power plants (1- to 10-MW nominal size) offer an attractive way of helping the world meet its future energy needs. The paper describes the characteristics of a conceptual near-term plant (about 1 MW) and a potential 1990 commercial version. The basic system concept is one in which steam is generated using two-axis tracking, parabolic dish, and point-focusing collectors. The steam is transported through low-loss piping to a central steam turbine generator unit where it is converted to electricity. The plants have no energy storage and their output power level varies with the solar insolation level. This system concept, which is firmly based on state-of-the-art technology, is projected to offer one of the fastest paths for U.S. commercialization of solar thermal electric power plants through moderate technology advances and mass production.

  2. Electrically Small Folded Slot Antenna Utilizing Capacitive Loaded Slot Lines

    NASA Technical Reports Server (NTRS)

    Scardelletti, Maximilian C.; Ponchak, George E.; Merritt, Shane; Minor, John S.; Zorman, Christian A.

    2007-01-01

    This paper presents an electrically small, coplanar waveguide fed, folded slot antenna that uses capacitive loading. Several antennas are fabricated with and without capacitive loading to demonstrate the ability of this design approach to reduce the resonant frequency of the antenna, which is analogous to reducing the antenna size. The antennas are fabricated on Cu-clad Rogers Duriod(TM) 6006 with multilayer chip capacitors to load the antennas. Simulated and measured results show close agreement, thus, validating the approach. The electrically small antennas have a measured return loss greater than 15 dB and a gain of 5.4, 5.6, and 2.7 dBi at 4.3, 3.95, and 3.65 GHz, respectively.

  3. Hybrid analysis of EM radiation and scattering by composite slot-blade cavity-backed antennas on the surface of electrically large smooth convex cylinders

    NASA Astrophysics Data System (ADS)

    Tseng, Huan-Wan

    1998-07-01

    In the first part of this work, a hybrid approach is developed, which combines the asymptotic high-frequency based uniform geometrical theory of diffraction (UTD) ray technique with a numerical method of moments (MM), to analyze the EM scattering of blade, slot, and composite slot-blade cavity backed antenna structures, respectively residing on the surface of electrically large circular cylinders. The MM is used to solve an integral equation formulation for the unknown equivalent current distributions over the blade and the slot. In that MM solution of the integral equation formulation, a UTD approximation for the dyadic Green's function for a perfectly conducting circular cylinder is employed to calculate the excitation vector by an incoming local plane wave. After these equivalent current distributions become known via the MM solutions, the UTD dyadic Green's functions are next also used to calculate the radiation from these equivalent current distributions in the presence of the circular cylinder. The UTD can describe the effects of the large cylinder in a rather simple closed form fashion while the MM is used essentially to deal with the much smaller blade and slot antennas which cannot directly be analyzed by the UTD. In the second part of this work, this hybrid MM/UTD technique is employed to analyze the radiation from a composite slot-blade cavity backed antenna located on realistic aircraft configurations. The excitation of the antenna is due to a delta gap generator in a thin-wire probe feed that is placed inside a rectangular cavity. The MM procedure is used first to solve coupled integral equations that are formulated for the unknown equivalent electric current distribution on the blade and the unknown equivalent magnetic current distribution on the slot, when this composite slot-blade antenna configuration resides on an infinite ground plane. Finally the UTD is used to efficiently and accurately calculate the radiation from these equivalent current

  4. Normal and abnormal electrical propagation in the small intestine.

    PubMed

    Lammers, W J E P

    2015-02-01

    As in other muscular organs, small intestinal motility is determined to a large degree by the electrical activities that occur in the smooth muscle layers of the small intestine. In recent decades, the interstitial cells of Cajal, located in the myenteric plexus, have been shown to be responsible for the generation and propagation of the electrical impulse: the slow wave. It was also known that the slow waves as such do not cause contraction, but that the action potentials ('spikes') that are generated by the slow waves are responsible for the contractions. Recording from large number of extracellular electrodes simultaneously is one method to determine origin and pattern of propagation of these electrical signals. This review reports the characteristics of slow wave propagation through the intestinal tube, the occurrence of propagation blocks along its length, which explains the well-known decrease in frequency, and the specific propagation pattern of the spikes that follow the slow waves. But the value of high-resolution mapping is highest in discovering and analysing mechanisms of arrhythmias in the gut. Most recently, circus movements (also called 're-entries') have been described in the small intestine in several species. Moreover, several types of re-entries have now been described, some similar to what may occur in the heart, such as functional re-entries, but others more unique to the small intestine, such as circumferential re-entry. These findings seem to suggest the possibilities of hitherto unknown pathologies that may be present in the small intestine. PMID:25156937

  5. Small intestinal model for electrically propelled capsule endoscopy

    PubMed Central

    2011-01-01

    The aim of this research is to propose a small intestine model for electrically propelled capsule endoscopy. The electrical stimulus can cause contraction of the small intestine and propel the capsule along the lumen. The proposed model considered the drag and friction from the small intestine using a thin walled model and Stokes' drag equation. Further, contraction force from the small intestine was modeled by using regression analysis. From the proposed model, the acceleration and velocity of various exterior shapes of capsule were calculated, and two exterior shapes of capsules were proposed based on the internal volume of the capsules. The proposed capsules were fabricated and animal experiments were conducted. One of the proposed capsules showed an average (SD) velocity in forward direction of 2.91 ± 0.99 mm/s and 2.23 ± 0.78 mm/s in the backward direction, which was 5.2 times faster than that obtained in previous research. The proposed model can predict locomotion of the capsule based on various exterior shapes of the capsule. PMID:22177218

  6. Decay of H atoms excited in small electric fields

    SciTech Connect

    Van Zyl, B.; Van Zyl, B.K.; Westerveld, W.B.

    1988-06-01

    The branching ratios for radiative decay of H atoms excited in small electric fields (0--5 Vcm) have been calculated for the nl states up to n = 6. A simple computational procedure was employed, allowing only for Stark-effect mixing of levels with the same values of the quantum numbers (n,j,m/sub j/). The results are compared with more detailed calculations available for 3l-state decay made using the density-matrix formalism, and new calculations of this type reported here for 4l-state decay. In conjunction with theory, this allowed the domain of validity of the simple computational procedure to be established as a function of n. The results show that the branching ratios depend quite strongly on electric-field magnitude, pointing to the need to exercise caution in measurements of H emissions, and in application of the available data to other problems.

  7. Small hydro-electric potential: West Poverty Bay region

    NASA Astrophysics Data System (ADS)

    1981-07-01

    Six schemes in the Bay of Plenty Electric Power Board area and two in the Poverty Bay Electric Power Board area, of which five and one, respectively are below the economic limit of $2400/kW were identified. Only three appear both economically and environmentally acceptable. The schemes identified are not very attractive on the national scale and could not be justified on local terms. It is recommended that a detailed feasibility study of the Takaputahi/Torere diversion is undertaken prior to a decision making to proceed with the Motu development, or if the proposals are dropped. The present low load and slow growth of the area is such that prior to a small hydroelectric scheme is built, demand for power has to be established.

  8. Torque vectoring for improving stability of small electric vehicles

    NASA Astrophysics Data System (ADS)

    Grzegożek, W.; Weigel-Milleret, K.

    2016-09-01

    The electric vehicles solutions based on the individually controlled electric motors propel a single wheel allow to improve the dynamic properties of the vehicle by varying the distribution of the driving torque. Most of the literature refer to the vehicles with a track typical for passenger cars. This paper examines whether the narrow vehicle (with a very small track) torque vectoring bring a noticeable change of the understeer characteristics and whether torque vectoring is possible to use in securing a narrow vehicle from roll over (roll mitigation). The paper contains road tests of the steering characteristics (steady state understeer characteristic quasi-static acceleration with a fixed steering wheel (SH = const) and on the constant radius track (R = const)) of the narrow vehicle. The vehicle understeer characteristic as a function of a power distribution is presented.

  9. LiNbO3 Cylinder Fiber

    NASA Technical Reports Server (NTRS)

    Kornreich, Philip

    2004-01-01

    We have successfully fabricate optical fiber with a thin layer of LiNbO3 at the boundary of the glass core and clear glass cladding. The construction of this fiber is based on our successful Semiconductor Cylinder Fibers (SCF). A schematic representation of a LiN bo, Cylinder Fiber. These fibers can be used as light modulators, sonar detectors and in other applications. The core diameter of the fiber is sufficiently small compared to the light wavelength and the indices of refraction of the core and cladding glasses are sufficiently close in value so that there is sufficient light at the core cladding boundary to interact with the LiNbO3 layer. This fiber functions best when just a single light mode propagates through the fiber. The idea for a LiNbO3 Cylinder Fiber came from Dr. Tracee Jamison of NASA. The optical properties of LiNbO3 can be changed with strain or the application of an electric field. Thus these fibers can be used as acoustic sensors as for example in a sonar. They can also be used as electric field operated light modulators. However, for this application the fibers would be made with a cross section in the form of a "D". The core with its surrounding LiNbO, layer would be close to the flat portion of the "D" shaped fiber. Two metal contacts would be deposited on the flat portion of the fiber on either side of the core. A voltage applied across these contacts will result in an electric field in the core region that can be used for modulating the optical properties of the LiNbO3 layer. To our knowledge this is the first ever LiNbO3 Cylinder Fiber made.

  10. LiNbO3 Cylinder Fiber

    NASA Technical Reports Server (NTRS)

    2004-01-01

    We have successfully fabricate optical fiber with a thin layer of LiNbO3 at the boundary of the glass core and dear glass cladding. The construction of this fiber is based on our successful Semiconductor Cylinder Fibers (SCF). A schematic representation of a LiNbO3 Cylinder Fiber is shown. These fibers can be used as light modulators, sonar detectors and in other applications. The core diameter of the fiber is sufficiently small compared to the light wavelength and the indices of refraction of the core and cladding glasses are sufficiently close in value so that there is sufficient light at the core cladding boundary to interact with the LiNbO3 layer. This fiber functions best when just a single light mode propagates through the fiber. The idea for a LiNbO3 Cylinder Fiber came from Dr. Tracee Jamison of NASA. The optical properties of LiNbO3 can be changed with strain or the application of an electric field. Thus these fibers can be used as acoustic sensors as for example in a sonar. They can also be used as electric field operated light modulators. However, for this application the fibers would be made with a cross section in the form of a 'D'. The core with its surrounding LiNbO, layer would be close to the flat portion of the 'D' shaped fiber. Two metal contacts would be deposited on the flat portion of the fiber on either side of the core. A voltage applied across these contacts will result in an electric field in the core region that can be used for modulating the optical properties of the LiNbO, layer. To our knowledge this is the first ever LiNbO, Cylinder Fiber made.

  11. Small Power Systems Solar Electric Workshop Proceedings. Volume 1: Executive report. Volume 2: Invited papers

    NASA Technical Reports Server (NTRS)

    Ferber, R. (Editor); Evans, D. (Editor)

    1978-01-01

    The background, objectives and methodology used for the Small Power Systems Solar Electric Workshop are described, and a summary of the results and conclusions developed at the workshop regarding small solar thermal electric power systems is presented.

  12. Carbon-carbon cylinder block

    NASA Technical Reports Server (NTRS)

    Ransone, Philip O. (Inventor)

    1998-01-01

    A lightweight cylinder block composed of carbon-carbon is disclosed. The use of carbon-carbon over conventional materials, such as cast iron or aluminum, reduces the weight of the cylinder block and improves thermal efficiency of the internal combustion reciprocating engine. Due to the negligible coefficient of thermal expansion and unique strength at elevated temperatures of carbon-carbon, the piston-to-cylinder wall clearance can be small, especially when the carbon-carbon cylinder block is used in conjunction with a carbon-carbon piston. Use of the carbon-carbon cylinder block has the effect of reducing the weight of other reciprocating engine components allowing the piston to run at higher speeds and improving specific engine performance.

  13. A modular electric power system test bed for small spacecraft

    NASA Technical Reports Server (NTRS)

    Button, Robert M.; Baez, Anastacio N.

    1994-01-01

    In the new climate of smaller, faster, and cheaper space science satellites, a new power system topology has been developed at the NASA Lewis Research Center. This new topology is based on a series connected boost converter (SCBC) and can greatly affect the size, weight, fault tolerance, and cost of any small spacecraft using photovoltaic solar arrays. The paper presents electric power system design factors and requirements as background information. The series connected boost converter topology is discussed and several advantages over existing technologies are illustrated. Besides being small, lightweight, and efficient, this topology has the added benefit of inherent fault tolerance. A positive ground power system test bed has been developed for the TROPIX spacecraft program. Performance of the SCBC in the test bed is described in detail. SCBC efficiencies of 95 percent to 98 percent have been measured. Finally, a modular, photovoltaic regulator 'kit' concept is presented. Two SCBC's are used to regulate solar array charging of batteries and to provide 'utilitytype' power to the user loads. The kit's modularity will allow a spacecraft electric power system to be built from off-the-shelf hardware; resulting in smaller, faster, and cheaper spacecraft.

  14. A solar thermal electric power plant for small communities

    NASA Technical Reports Server (NTRS)

    Holl, R. J.

    1979-01-01

    A solar power plant has been designed with a rating of 1000-kW electric and a 0.4 annual capacity factor. It was configured as a prototype for plants in the 1000 to 10,000-kWe size range for application to small communities or industrial users either grid-connected or isolated from a utility grid. A small central receiver was selected for solar energy collection after being compared with alternative distributed collectors. Further trade studies resulted in the selection of Hitec (heat transfer salt composed of 53 percent KNO3, 40 percent NaNO2, 7 percent NaNO3) as both the receiver coolant and the sensible heat thermal stroage medium and the steam Rankine cycle for power conversion. The plant is configured with road-transportable units to accommodate remote sites and minimize site assembly requirements. Results of the analyses indicate that busbar energy costs are competitive with diesel-electric plants in certain situations, e.g., off-grid, remote regions with high insolation. Sensitivity of energy costs to plant power rating and system capacity factor are given.

  15. 10 CFR 431.446 - Small electric motors energy conservation standards and their effective dates.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 3 2011-01-01 2011-01-01 false Small electric motors energy conservation standards and... EFFICIENCY PROGRAM FOR CERTAIN COMMERCIAL AND INDUSTRIAL EQUIPMENT Small Electric Motors Energy Conservation Standards § 431.446 Small electric motors energy conservation standards and their effective dates. (a)...

  16. 10 CFR 431.446 - Small electric motors energy conservation standards and their effective dates. [Reserved

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 3 2010-01-01 2010-01-01 false Small electric motors energy conservation standards and... EFFICIENCY PROGRAM FOR CERTAIN COMMERCIAL AND INDUSTRIAL EQUIPMENT Small Electric Motors Energy Conservation Standards § 431.446 Small electric motors energy conservation standards and their effective dates....

  17. 10 CFR 431.446 - Small electric motors energy conservation standards and their effective dates.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 3 2014-01-01 2014-01-01 false Small electric motors energy conservation standards and... EFFICIENCY PROGRAM FOR CERTAIN COMMERCIAL AND INDUSTRIAL EQUIPMENT Small Electric Motors Energy Conservation Standards § 431.446 Small electric motors energy conservation standards and their effective dates. (a)...

  18. 10 CFR 431.446 - Small electric motors energy conservation standards and their effective dates.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 3 2012-01-01 2012-01-01 false Small electric motors energy conservation standards and... EFFICIENCY PROGRAM FOR CERTAIN COMMERCIAL AND INDUSTRIAL EQUIPMENT Small Electric Motors Energy Conservation Standards § 431.446 Small electric motors energy conservation standards and their effective dates. (a)...

  19. Massless rotating fermions inside a cylinder

    SciTech Connect

    Ambruş, Victor E.; Winstanley, Elizabeth

    2015-12-07

    We study rotating thermal states of a massless quantum fermion field inside a cylinder in Minkowski space-time. Two possible boundary conditions for the fermion field on the cylinder are considered: the spectral and MIT bag boundary conditions. If the radius of the cylinder is sufficiently small, rotating thermal expectation values are finite everywhere inside the cylinder. We also study the Casimir divergences on the boundary. The rotating thermal expectation values and the Casimir divergences have different properties depending on the boundary conditions applied at the cylinder. This is due to the local nature of the MIT bag boundary condition, while the spectral boundary condition is nonlocal.

  20. Electric fields and current densities under small Florida thunderstorms

    NASA Technical Reports Server (NTRS)

    Deaver, Lance E.; Krider, E. P.

    1991-01-01

    Results are presented of measurements of the electric field E and Maxwell current density that were performed simultaneously under and near small Florida thunderstorms. It is shown that the amplitude of JM is of the order of 1 nA/sq cm or less in the absence of precipitation and that there are regular time variations in JM during the intervals between lightning discharges that tend to have the same shapes after different discharges in different storms. It is argued that the major causes of time variations in JM between lightning discharges are currents that flow in the finitely conducting atmosphere in response to the field changes rather than rapid time variations in the strength of cloud current sources. The displacement current densities that are computed from the E records dominate JM except when there is precipitation, when E is large and steady, or when E is unusually noisy.

  1. Small-scale electric generators for arctic applications

    NASA Astrophysics Data System (ADS)

    Lamp, Thomas R.

    1995-01-01

    Forest fires that have endangered remote US Air Force sites equipped with radioisotope thermoelectric generators (RTGs) has prompted the assessment of power generating systems as substitutes for RTGs in small scale (10-120 watt) applications. A team of scientists and engineers of the US Air Forces' Wright Laboratory conductd an assessment of electrical power technologies for use by the Air Force in remote, harsh environments. The surprisingly high logistics costs of operating fossil fuel generators resulted in the extension of the assessment to non-RTG sites. The candidate power sources must operate unattended for long periods at a high level of operational reliability. Selection of the optimum power generation technology is complicated and heavily driven by the severe operating environment and compounded by the remoteness of the location. It is these site-related characteristics, more than any other, that drive the selection of a safe and economical power source for Arctic applications. A number of proven power generation technologies were evaluated. The assessment concluded that RGTs are clearly the safest, most reliable, and most economical approach to supplying electrical power for remote, difficult to assess locations. The assessment also indicated that the logistics costs associated with combustion driven generator systems could be substantially reduced through the use of conversion technologies which have been previously developed for space power applications.

  2. 49 CFR 178.61 - Specification 4BW welded steel cylinders with electric-arc welded longitudinal seam.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ..., adequate to prevent leakage. (4) Closure of fittings, boss or pads must be adequate to prevent leakage. (i... a maximum wall stress of 24,000 p.s.i. in the formula described in paragraph (f)(4) of this section.... (3) Longitudinal seams in shells must conform to the following: (i) Longitudinal electric-arc...

  3. 49 CFR 178.61 - Specification 4BW welded steel cylinders with electric-arc welded longitudinal seam.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ..., adequate to prevent leakage. (4) Closure of fittings, boss or pads must be adequate to prevent leakage. (i... a maximum wall stress of 24,000 p.s.i. in the formula described in paragraph (f)(4) of this section.... (3) Longitudinal seams in shells must conform to the following: (i) Longitudinal electric-arc...

  4. Electrical Ground Support Equipment (EGSE) Design for Small Satellite

    NASA Astrophysics Data System (ADS)

    Park, Jong-Oh; Choi, Jong-Yoen; Lim, Seong-Bin; Kwon, Jae-Wook; Youn, Young-Su; Chun, Yong-Sik; Lee, Sang-Seol

    2002-09-01

    This paper describes EGSE design for the small satellite such like KOMPSAT-2 satellite. Recent design trend of small satellite and EGSE is to take short development time and less cost. For this purpose, the design for KOMPSAT-2 satellite and EGSE are not much modified from KOMPSAT-1 heritage. It means that it is able to be accommodated the verified hardware and software modules used in KOMPSAT-1 satellite program if possible. The objective of EGSE is to provide hardware and software for efficient electrical testing of integrated KOMPSAT-2 satellite in three general categories. (1) Simulators for ground testing (e.g. solar-simulation power, earth scenes, horizons and sun sensor). (2) Ground station type satellite data acquisition and processing test sets. (3) Overall control of satellite using hardline datum. In KOMPSAT (KOrea Multi-Purpose SATellite) program, KOMPSAT-2 EGSE was developed to support satellite integration and test activities. The KOMPSAT-2 EGSE was designed in parallel with satellite design. Consequently, the KOMPSAT-2 EGSE was based on the KOMPSAT-1 heritage since the spacecraft design followed the heritage. The KOMPSAT-2 baseline was elaborated by taking advantage of experience from KOMPSAT-1 program. The EGSE of KOMPSAT-2 design concept is generic modular design with preference in part selection with commercial off-the-shelf which were proven from KOMPSAT-1 programs, flexible/user friendly operational environment (graphical interface preferred), minimized new design and self test capability.

  5. Electrically Small Microstrip Quarter-Wave Monopole Antennas

    NASA Technical Reports Server (NTRS)

    Young, W. Robert

    2004-01-01

    Microstrip-patch-style antennas that generate monopole radiation patterns similar to those of quarter-wave whip antennas can be designed to have dimensions smaller than those needed heretofore for this purpose, by taking advantage of a feed configuration different from the conventional one. The large sizes necessitated by the conventional feed configuration have, until now, made such antennas impractical for frequencies below about 800 MHz: for example, at 200 MHz, the conventional feed configuration necessitates a patch diameter of about 8 ft (.2.4 m) . too large, for example, for mounting on the roof of an automobile or on a small or medium-size aircraft. By making it possible to reduce diameters to between a tenth and a third of that necessitated by the conventional feed configuration, the modified configuration makes it possible to install such antennas in places where they could not previously be installed and thereby helps to realize the potential advantages (concealment and/or reduction of aerodynamic drag) of microstrip versus whip antennas. In both the conventional approach and the innovative approach, a microstrip-patch (or microstrip-patch-style) antenna for generating a monopole radiation pattern includes an electrically conductive patch or plate separated from an electrically conductive ground plane by a layer of electrically insulating material. In the conventional approach, the electrically insulating layer is typically a printed-circuit board about 1/16 in. (.1.6 mm) thick. Ordinarily, a coaxial cable from a transmitter, receiver, or transceiver is attached at the center on the ground-plane side, the shield of the cable being electrically connected to the ground plane. In the conventional approach, the coaxial cable is mated with a connector mounted on the ground plane. The center pin of this connector connects to the center of the coaxial cable and passes through a hole in the ground plane and a small hole in the insulating layer and then connects

  6. Analytical model for the levitation force between a small magnet and a superconducting cylinder in the critical state

    NASA Astrophysics Data System (ADS)

    de la Cruz, Artorix; Badía, Antonio

    2002-08-01

    In this work a simple analytical model is presented, which allows to obtain closed-form expressions for the maximum magnetic field trapped by a cylindrical superconductor as well as the levitation force between the sample and a small magnet. Previous models of this kind could not properly account for the behaviour of the repulsion force with the variation of the sample dimensions. In particular, the so-called Js+ Jv model (J. Appl. Phys. 72 (1992) 1013) incorporates size effects by means of a surface current density ( Js) which tends to zero for disc-shaped samples. However, we show that the features encountered both in experimental works and numerical models reported in the literature can be reproduced by a suitable modification of the Js+ Jv model. Analytical expressions of the levitation force are obtained as a function of length and radius of the sample and as well the superconductor-magnet distance.

  7. Preconditioning of the Singular Domain Integral Equation Method for Transverse Electric Scattering on High-Contrast Inhomogeneous Cylinders

    NASA Astrophysics Data System (ADS)

    Zouros, Grigorios P.; Budko, Neil V.

    2011-09-01

    Preconditioning of the domain integral equation (DIE) method for electromagnetic scattering is considered. The present study is focused on the transverse electric (TE) scattering from inhomogeneous objects having high permittivity value. We explicity derive the symbol and the essential spectrum of the two-dimensional singular integral operator, its left regularizer, and obtain a manifestly Fredholm operator of the form `identity plus compact'. This regularized system shows an improved performance in terms of convergence, and an even better performance is achieved by further applying deflation on a finite set of largest-magnitude eigenvalues.

  8. 2-SR-based electrically small antenna for RFID applications

    NASA Astrophysics Data System (ADS)

    Paredes, Ferran; Zuffanelli, Simone; Aguilà, Pau; Zamora, Gerard; Martin, Ferran; Bonache, Jordi

    2016-04-01

    In this work, the 2-turn spiral resonator (2-SR) is proposed as an electrically small antenna for passive radio frequency identification (RFID) tags at the European ultra-high frequency (UHF) band. The radiation properties are studied in order to explore the viability of the 2-SR applied to tag antenna design. Based on analytical calculations, the radiation pattern is found to provide a cancelation of the radiation nulls. This results in a mitigation of the blind spots in the read range, which are present in typical UHF-RFID tags as an undesired feature. As a proof of concept, a passive tag of size 35 mm × 40 mm (λ 0/10 × λ 0/9) based on the 2-SR antenna is designed and fabricated. Good radiation efficiency (75 %) and a quasi-isotropic radiation pattern are obtained. The experimental tag read range for different directions is in good agreement with the simulation results. The measured read range exhibits maximum and minimum values of 6.7 and 3.5 m, respectively.

  9. Enhancement of polarizabilities of cylinders with cylinder-slab resonances

    PubMed Central

    Xiao, Meng; Huang, Xueqin; Liu, H.; Chan, C. T.

    2015-01-01

    If an object is very small in size compared with the wavelength of light, it does not scatter light efficiently. It is hence difficult to detect a very small object with light. We show using analytic theory as well as full wave numerical calculation that the effective polarizability of a small cylinder can be greatly enhanced by coupling it with a superlens type metamaterial slab. This kind of enhancement is not due to the individual resonance effect of the metamaterial slab, nor due to that of the object, but is caused by a collective resonant mode between the cylinder and the slab. We show that this type of particle-slab resonance which makes a small two-dimensional object much “brighter” is actually closely related to the reverse effect known in the literature as “cloaking by anomalous resonance” which can make a small cylinder undetectable. We also show that the enhancement of polarizability can lead to strongly enhanced electromagnetic forces that can be attractive or repulsive, depending on the material properties of the cylinder. PMID:25641391

  10. Blower Cooling of Finned Cylinders

    NASA Technical Reports Server (NTRS)

    Schey, Oscar W; Ellerbrock, Herman H , Jr

    1937-01-01

    Several electrically heated finned steel cylinders enclosed in jackets were cooled by air from a blower. The effect of the air conditions and fin dimensions on the average surface heat-transfer coefficient q and the power required to force the air around the cylinders were determined. Tests were conducted at air velocities between the fins from 10 to 130 miles per hour and at specific weights of the air varying from 0.046 to 0.074 pound per cubic foot. The fin dimensions of the cylinders covered a range in pitches from 0.057 to 0.25 inch average fin thicknesses from 0.035 to 0.04 inch, and fin widths from 0.67 to 1.22 inches.

  11. 10 CFR 431.445 - Determination of small electric motor efficiency.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... COMMERCIAL AND INDUSTRIAL EQUIPMENT Small Electric Motors Test Procedures § 431.445 Determination of small... the mechanical and electrical characteristics of that basic model, and (ii) Based on engineering or... Department of Energy records showing the method or methods used; the mathematical model, the engineering...

  12. 10 CFR 431.445 - Determination of small electric motor efficiency.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... COMMERCIAL AND INDUSTRIAL EQUIPMENT Small Electric Motors Test Procedures § 431.445 Determination of small... the mechanical and electrical characteristics of that basic model, and (ii) Based on engineering or... Department of Energy records showing the method or methods used; the mathematical model, the engineering...

  13. Quick release engine cylinder

    DOEpatents

    Sunnarborg, Duane A.

    2000-01-01

    A quick release engine cylinder allows optical access to an essentially unaltered combustion chamber, is suitable for use with actual combustion processes, and is amenable to rapid and repeated disassembly and cleaning. A cylinder member, adapted to constrain a piston to a defined path through the cylinder member, sealingly engages a cylinder head to provide a production-like combustion chamber. A support member mounts with the cylinder member. The support-to-cylinder mounting allows two relationships therebetween. In the first mounting relationship, the support engages the cylinder member and restrains the cylinder against the head. In the second mounting relationship, the cylinder member can pass through the support member, moving away from the head and providing access to the piston-top and head.

  14. 6. FLYWHEEL FOR THE 32/28 STRUCTURAL MILL. THE SMALL ELECTRIC ...

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

    6. FLYWHEEL FOR THE 32/28 STRUCTURAL MILL. THE SMALL ELECTRIC MOTOR IN FOREGROUND MAY HAVE BEEN USED TO HELP START THE MILL. - U.S. Steel Homestead Works, Structural Mill, Along Monongahela River, Homestead, Allegheny County, PA

  15. Speed control of a small turbine using electrical loading.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Small wind turbines with permanent magnet alternators (PMA) seldom have active speed control systems. The turbines rely on passive mechanisms such as furling and/or blade flutter to control the rotational speed. These passive methods cause high mechanical stresses and undesirable noise. One metho...

  16. Cylinder Test Specification

    SciTech Connect

    Richard Catanach; Larry Hill; Herbert Harry; Ernest Aragon; Don Murk

    1999-10-01

    The purpose of the cylinder testis two-fold: (1) to characterize the metal-pushing ability of an explosive relative to that of other explosives as evaluated by the E{sub 19} cylinder energy and the G{sub 19} Gurney energy and (2) to help establish the explosive product equation-of-state (historically, the Jones-Wilkins-Lee (JWL) equation). This specification details the material requirements and procedures necessary to assemble and fire a typical Los Alamos National Laboratory (LANL) cylinder test. Strict adherence to the cylinder. material properties, machining tolerances, material heat-treatment and etching processes, and high explosive machining tolerances is essential for test-to-test consistency and to maximize radial wall expansions. Assembly and setup of the cylinder test require precise attention to detail, especially when placing intricate pin wires on the cylinder wall. The cylinder test is typically fired outdoors and at ambient temperature.

  17. 75 FR 10873 - Energy Conservation Program: Energy Conservation Standards for Small Electric Motors

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-09

    ... electric motor energy conservation standards. 74 FR 61410. Shortly after, DOE also published on its Web... recently adopted for small electric motors, 74 FR 32059 (July 7, 2009), appear at Title 10, Code of Federal...-run (CSCR) motors. 71 FR 38799, 38800-01 (July 10, 2006). In June 2006, DOE issued a report in...

  18. 10 CFR 431.445 - Determination of small electric motor efficiency.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... Section 431.445 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY EFFICIENCY PROGRAM FOR CERTAIN... electric motor efficiency. (a) Scope. When a party determines the energy efficiency of a small electric... determine its energy efficiency must be carried out in accordance with paragraph (c) of this section....

  19. 10 CFR 431.445 - Determination of small electric motor efficiency.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... Section 431.445 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY EFFICIENCY PROGRAM FOR CERTAIN... electric motor efficiency. (a) Scope. When a party determines the energy efficiency of a small electric... prior 12-month period before the effective date of the energy efficiency standard, whichever is...

  20. Electrical stimulation of a small brain area reversibly disrupts consciousness.

    PubMed

    Koubeissi, Mohamad Z; Bartolomei, Fabrice; Beltagy, Abdelrahman; Picard, Fabienne

    2014-08-01

    The neural mechanisms that underlie consciousness are not fully understood. We describe a region in the human brain where electrical stimulation reproducibly disrupted consciousness. A 54-year-old woman with intractable epilepsy underwent depth electrode implantation and electrical stimulation mapping. The electrode whose stimulation disrupted consciousness was between the left claustrum and anterior-dorsal insula. Stimulation of electrodes within 5mm did not affect consciousness. We studied the interdependencies among depth recording signals as a function of time by nonlinear regression analysis (h(2) coefficient) during stimulations that altered consciousness and stimulations of the same electrode at lower current intensities that were asymptomatic. Stimulation of the claustral electrode reproducibly resulted in a complete arrest of volitional behavior, unresponsiveness, and amnesia without negative motor symptoms or mere aphasia. The disruption of consciousness did not outlast the stimulation and occurred without any epileptiform discharges. We found a significant increase in correlation for interactions affecting medial parietal and posterior frontal channels during stimulations that disrupted consciousness compared with those that did not. Our findings suggest that the left claustrum/anterior insula is an important part of a network that subserves consciousness and that disruption of consciousness is related to increased EEG signal synchrony within frontal-parietal networks.

  1. Electrical stimulation of a small brain area reversibly disrupts consciousness.

    PubMed

    Koubeissi, Mohamad Z; Bartolomei, Fabrice; Beltagy, Abdelrahman; Picard, Fabienne

    2014-08-01

    The neural mechanisms that underlie consciousness are not fully understood. We describe a region in the human brain where electrical stimulation reproducibly disrupted consciousness. A 54-year-old woman with intractable epilepsy underwent depth electrode implantation and electrical stimulation mapping. The electrode whose stimulation disrupted consciousness was between the left claustrum and anterior-dorsal insula. Stimulation of electrodes within 5mm did not affect consciousness. We studied the interdependencies among depth recording signals as a function of time by nonlinear regression analysis (h(2) coefficient) during stimulations that altered consciousness and stimulations of the same electrode at lower current intensities that were asymptomatic. Stimulation of the claustral electrode reproducibly resulted in a complete arrest of volitional behavior, unresponsiveness, and amnesia without negative motor symptoms or mere aphasia. The disruption of consciousness did not outlast the stimulation and occurred without any epileptiform discharges. We found a significant increase in correlation for interactions affecting medial parietal and posterior frontal channels during stimulations that disrupted consciousness compared with those that did not. Our findings suggest that the left claustrum/anterior insula is an important part of a network that subserves consciousness and that disruption of consciousness is related to increased EEG signal synchrony within frontal-parietal networks. PMID:24967698

  2. An Analytical Performance Assessment of a Fuel Cell-powered, Small Electric Airplane

    NASA Technical Reports Server (NTRS)

    Berton, Jeffrey J.; Freeh, Joshua E.; Wickenheiser, Timothy J.

    2003-01-01

    Rapidly emerging fuel cell power technologies may be used to launch a new revolution of electric propulsion systems for light aircraft. Future small electric airplanes using fuel cell technologies hold the promise of high reliability, low maintenance, low noise, and with exception of water vapor zero emissions. This paper describes an analytical feasibility and performance assessment conducted by NASA's Glenn Research Center of a fuel cell-powered, propeller-driven, small electric airplane based on a model of the MCR 01 two-place kitplane.

  3. Slow light and band gaps in metallodielectric cylinder arrays.

    PubMed

    Shainline, Jeffrey M; Xu, Jimmy

    2009-05-25

    We consider two-dimensional three-component photonic crystals wherein one component is modeled as a drude-dispersive metal. It is found that the dispersion relation of light in this environment depends critically on the configuration of the metallic and dielectric components. In particular, for the case of an incident electromagnetic wave with electric field vector parallel to the axis of the cylinders it is shown that the presence of dielectric shells covering the metallic cylinders leads to a closing of the structural band gap with increased filling factor, as would be expected for a purely dielectric photonic crystal. For the same polarization, the photonic band structure of an array of metallic shell cylinders with dielectric cores do not show the closing of the structural band gap with increased filling factor of the metallic component. In this geometry, the photonic band structure contains bands with very small values of group velocity with some bands having a maximum of group velocity as small as .05c. PMID:19466137

  4. The GEA methods for light scattering by dielectric cylinder with fixed orientations

    NASA Astrophysics Data System (ADS)

    Oh, Jounghoon

    1999-11-01

    The GEA method is employed to study light scattering by dielectric cylinder with fixed orientations. A simple formula is obtained for a thin cylinder. The results from a dielectric cylinder with fixed orientations are compared numerically and found to agree well with T- matrix method for small angle scattering. The numerical results for a cylinder are obtained.

  5. Ultra-small single-negative electric metamaterials for electromagnetic coupling reduction of microstrip antenna array.

    PubMed

    Xu, He-Xiu; Wang, Guang-Ming; Qi, Mei-Qing; Zeng, Hui-Yong

    2012-09-24

    We report initially the design, fabrication and measurement of using waveguided electric metamaterials (MTM) in the design of closely-spaced microtrip antenna arrays with mutual coupling reduction. The complementary spiral ring resonators (CSRs) which exhibit single negative resonant permittivity around 3.5GHz are used as the basic electric MTM element. For verification, two CSRs with two and three concentric rings are considered, respectively. By properly arranging these well engineered waveguided MTMs between two H-plane coupled patch antennas, both numerical and measured results indicate that more than 8.4 dB mutual coupling reduction is obtained. The mechanism has been studied from a physical insight. The electric MTM element is electrically small, enabling the resultant antenna array to exhibit a small separation (λo/8 at the operating wavelength) and thus a high directivity. The proposed strategy opens an avenue to new types of antenna with super performances and can be generalized for other electric resonators.

  6. PHOBOS Exploration using Two Small Solar Electric Propulsion Spacecraft

    NASA Technical Reports Server (NTRS)

    Lang, Jared J.; Baker, John D.; Castillo-Rogez, Julie C.; McElrath, Timothy P.; Piacentine, Jamie S.; Snyder, J. Steve

    2012-01-01

    Primitive bodies are exciting targets for exploration as they provide clues to the early Solar system conditions and dynamical evolution. The two moons of Mars are particularly interesting because of their proximity to an astrobiological target. However, after four decades of Mars exploration, their origin and nature remain enigmatic. In addition, when considering the long-term objectives of the flexible path for the potential human exploration to Mars, Phobos and Deimos present exciting intermediate opportunities without the complication and expense of landing and ascending from the surface. As interest in these targets for the next frontier of human exploration grows, characterization missions designed specifically to examine surface properties, landing environments, and surface mapping prior to human exploration are becoming increasingly important. A precursor mission concept of this sort has been developed using two identical spacecraft designed from low cost, flight proven and certified off-the-shelf component and utilizing Solar Electric Propulsion (SEP) to orbit both targets as secondary payloads launched aboard any NASA or GTO launch. This precursor mission has the potential to address both precursor measurements that are strategic knowledge gaps and decadal science, including soil physical properties at the global and local (human) scale and the search for in situ resources.

  7. Some design considerations for small piezo-electrical ceramic transducers

    NASA Astrophysics Data System (ADS)

    Rijnja, H. A. J.

    1989-07-01

    The design parameters and the characteristics of small omnidirectional transducers, to be applied under water as projectors in the frequency range of about 1 kHz to 100 kHz and as hydrophones from very low frequencies up to again 100kHz are described. The transducers are constructed with piezoelectrical ceramic materials in the shape of hollow spheres, end capped tubes or piston (Tonpilz) elements. The highest source levels are obtained with spherical transducers as single omnidirectional sound sources. If larger arrays of sources are applied the array should be composed of single ended Tonpilz elements. The most sensitive receivers (hydrophones) are obtained with tangentially polarized end-capped tubes.

  8. Engine Cylinder Temperature Control

    DOEpatents

    Kilkenny, Jonathan Patrick; Duffy, Kevin Patrick

    2005-09-27

    A method and apparatus for controlling a temperature in a combustion cylinder in an internal combustion engine. The cylinder is fluidly connected to an intake manifold and an exhaust manifold. The method and apparatus includes increasing a back pressure associated with the exhaust manifold to a level sufficient to maintain a desired quantity of residual exhaust gas in the cylinder, and varying operation of an intake valve located between the intake manifold and the cylinder to an open duration sufficient to maintain a desired quantity of fresh air from the intake manifold to the cylinder, wherein controlling the quantities of residual exhaust gas and fresh air are performed to maintain the temperature in the cylinder at a desired level.

  9. Cylinder monitoring program

    SciTech Connect

    Alderson, J.H.

    1991-12-31

    Cylinders containing depleted uranium hexafluoride (UF{sub 6}) in storage at the Department of Energy (DOE) gaseous diffusion plants, managed by Martin Marietta Energy Systems, Inc., are being evaluated to determine their expected storage life. Cylinders evaluated recently have been in storage service for 30 to 40 years. In the present environment, the remaining life for these storage cylinders is estimated to be 30 years or greater. The group of cylinders involved in recent tests will continue to be monitored on a periodic basis, and other storage cylinders will be observed as on a statistical sample population. The program has been extended to all types of large capacity UF{sub 6} cylinders.

  10. Electrical transients of windturbines in a small power grid

    SciTech Connect

    Demoulias, C.S.; Dokopoulos, P.

    1996-09-01

    This paper presents field measurements and calculations on the disconnection and braking of Wind Turbines (WT) with rated power 60 kw and 100 kW in the grid of two Greek Islands. By means of a digital acquisition system with sampling frequency of 130 kHz, voltages and currents of the WT installations have been measured and analyzed just before and during the transient period. A simulation program has been used for this purpose. Results of simulation and measurements show in a wide range of good agreement. The simulation program was further used to investigate the disconnection process of WT under various circumstances. It is shown that during the WT disconnection, a sudden increase in stator currents may appear. So voltage dips may distort the power quality of the grid. Self-excitation of WT, with large induced voltage, occurs when they operate at low-load even with relatively small capacitive compensation. The amount of energy, that the brake of WT absorbs during the disconnection, has been studied under various disconnection procedures. Suggestions are made for the proper moment of brake application, so that the energy absorbed is minimum.

  11. Delamination of Composite Cylinders

    NASA Astrophysics Data System (ADS)

    Davies, Peter; Carlsson, Leif A.

    The delamination resistance of filament wound glass/epoxy cylinders has been characterized for a range of winding angles and fracture mode ratios using beam fracture specimens. The results reveal that the delamination fracture resistance increases with increasing winding angle and mode II (shear) fraction (GΠ/G). It was also found that interlaced fiber bundles in the filament wound cylinder wall acted as effective crack arresters in mode I loading. To examine the sensitivity of delamina-tion damage on the strength of the cylinders, external pressure tests were performed on filament-wound glass/epoxy composite cylinders with artificial defects and impact damage. The results revealed that the cylinder strength was insensitive to the presence of single delaminations but impact damage caused reductions in failure pressure. The insensitivity of the failure pressure to a single delamination is attributed to the absence of buckling of the delaminated sublaminates before the cylinder wall collapsed. The impacted cylinders contained multiple delaminations, which caused local reduction in the compressive load capability and reduction in failure pressure. The response of glass/epoxy cylinders was compared to impacted carbon reinforced cylinders. Carbon/epoxy is more sensitive to damage but retains higher implosion resistance while carbon/PEEK shows the opposite trend.

  12. Thin magnetic conductor substrate for placement-immune, electrically-small antennas.

    SciTech Connect

    Eubanks, Travis Wayne; McDonald, Jacob J.; Loui, Hung

    2011-09-01

    An antenna is considered to be placement-immune when the antenna operates effectively regardless of where it is placed. By building antennas on magnetic conductor materials, the radiated fields will be positively reinforced in the desired radiation direction instead of being negatively affected by the environment. Although this idea has been discussed thoroughly in theoretical research, the difficulty in building thin magnetic conductor materials necessary for in-phase field reflections prevents this technology from becoming more widespread. This project's purpose is to build and measure an electrically-small antenna on a new type of non-metallic, thin magnetic conductor. This problem has not been previously addressed because non-metallic, thin magnetic conductor materials have not yet been discovered. This work proposed the creation of an artificial magnetic conductor (AMC) with in-phase field reflections without using internal electric conductors, the placement of an electrically-small antenna on this magnetic conductor, and the development of a transmit-receive system that utilizes the substrate and electrically-small antenna. By not using internal electric conductors to create the AMC, the substrate thickness can be minimized. The electrically-small antenna will demonstrate the substrate's ability to make an antenna placement immune, and the transmit-receive system combines both the antenna and the substrate while adding a third layer of system complexity to demonstrate the complete idea.

  13. Maximal liquid bridges between horizontal cylinders

    NASA Astrophysics Data System (ADS)

    Cooray, Himantha; Huppert, Herbert E.; Neufeld, Jerome A.

    2016-08-01

    We investigate two-dimensional liquid bridges trapped between pairs of identical horizontal cylinders. The cylinders support forces owing to surface tension and hydrostatic pressure that balance the weight of the liquid. The shape of the liquid bridge is determined by analytically solving the nonlinear Laplace-Young equation. Parameters that maximize the trapping capacity (defined as the cross-sectional area of the liquid bridge) are then determined. The results show that these parameters can be approximated with simple relationships when the radius of the cylinders is small compared with the capillary length. For such small cylinders, liquid bridges with the largest cross-sectional area occur when the centre-to-centre distance between the cylinders is approximately twice the capillary length. The maximum trapping capacity for a pair of cylinders at a given separation is linearly related to the separation when it is small compared with the capillary length. The meniscus slope angle of the largest liquid bridge produced in this regime is also a linear function of the separation. We additionally derive approximate solutions for the profile of a liquid bridge, using the linearized Laplace-Young equation. These solutions analytically verify the above-mentioned relationships obtained for the maximization of the trapping capacity.

  14. Performance of ground-based high-frequency receiving arrays with electrically-small ground planes

    NASA Astrophysics Data System (ADS)

    Weiner, M. M.

    1991-09-01

    Electrically-small ground planes degrade the performance of ground-based high-frequency receiving arrays because the arrays are more susceptible to earth multipath, ground losses, and external currents on element feed cables. Performance degradations include a reduction in element directive gain near the horizon, distortion of the element azimuthal pattern, an increase in the system internal noise factor, and increases in the array factor root-mean-squared (rms) phase error and beam-pointing errors. The advantage of electrically-small ground planes is their relatively low cost of construction and maintenance.

  15. Achieving illusion and invisibility of inhomogeneous cylinders and spheres

    NASA Astrophysics Data System (ADS)

    Zhang, Lin; Shi, Yan; Liang, Chang-Hong

    2016-08-01

    This paper has developed a scattering cancellation technique to achieve illusion and invisibility of inhomogeneous cylinders and spheres. The inhomogeneous cylinders and spheres are modelled as many thin layers of piecewise homogeneous layers. For the two-layer cylindrical and spherical objects with the isotropic coatings, Mie series solutions to the resulting scattered fields are analyzed in the quasistatic limit, and thus geometric and electromagnetic parameters of the coatings are derived to realize the illusion and invisibility of the two-layer cylindrical and spherical objects. Following a further generalization step, the coating parameters are determined for the illusion and invisibility of the inhomogeneous cylinders and spheres composed of N piecewise homogeneous layers. With the proposed method, the electrically small inhomogeneous cylindrical and spherical objects with arbitrary media and conductor core can be hidden, and have illusion images generated by the objects with similar shapes but different electromagnetic parameters and geometric sizes. Numerical results are given to verify correctness and effectiveness of the proposed method.

  16. Theory of interacting dislocations on cylinders

    NASA Astrophysics Data System (ADS)

    Amir, Ariel; Paulose, Jayson; Nelson, David R.

    2013-04-01

    We study the mechanics and statistical physics of dislocations interacting on cylinders, motivated by the elongation of rod-shaped bacterial cell walls and cylindrical assemblies of colloidal particles subject to external stresses. The interaction energy and forces between dislocations are solved analytically, and analyzed asymptotically. The results of continuum elastic theory agree well with numerical simulations on finite lattices even for relatively small systems. Isolated dislocations on a cylinder act like grain boundaries. With colloidal crystals in mind, we show that saddle points are created by a Peach-Koehler force on the dislocations in the circumferential direction, causing dislocation pairs to unbind. The thermal nucleation rate of dislocation unbinding is calculated, for an arbitrary mobility tensor and external stress, including the case of a twist-induced Peach-Koehler force along the cylinder axis. Surprisingly rich phenomena arise for dislocations on cylinders, despite their vanishing Gaussian curvature.

  17. Tandem Cylinder Noise Predictions

    NASA Technical Reports Server (NTRS)

    Lockhard, David P.; Khorrami, Mehdi R.; CHoudhari, Meelan M.; Hutcheson, Florence V.; Brooks, Thomas F.; Stead, Daniel J.

    2007-01-01

    In an effort to better understand landing-gear noise sources, we have been examining a simplified configuration that still maintains some of the salient features of landing-gear flow fields. In particular, tandem cylinders have been studied because they model a variety of component level interactions. The present effort is directed at the case of two identical cylinders spatially separated in the streamwise direction by 3.7 diameters. Experimental measurements from the Basic Aerodynamic Research Tunnel (BART) and Quiet Flow Facility (QFF) at NASA Langley Research Center (LaRC) have provided steady surface pressures, detailed off-surface measurements of the flow field using Particle Image Velocimetry (PIV), hot-wire measurements in the wake of the rear cylinder, unsteady surface pressure data, and the radiated noise. The experiments were conducted at a Reynolds number of 166 105 based on the cylinder diameter. A trip was used on the upstream cylinder to insure a fully turbulent shedding process and simulate the effects of a high Reynolds number flow. The parallel computational effort uses the three-dimensional Navier-Stokes solver CFL3D with a hybrid, zonal turbulence model that turns off the turbulence production term everywhere except in a narrow ring surrounding solid surfaces. The current calculations further explore the influence of the grid resolution and spanwise extent on the flow and associated radiated noise. Extensive comparisons with the experimental data are used to assess the ability of the computations to simulate the details of the flow. The results show that the pressure fluctuations on the upstream cylinder, caused by vortex shedding, are smaller than those generated on the downstream cylinder by wake interaction. Consequently, the downstream cylinder dominates the noise radiation, producing an overall directivity pattern that is similar to that of an isolated cylinder. Only calculations based on the full length of the model span were able to

  18. Industrial Education. Mini-Course Cluster: Bikes, Electricity, Small Engines. [Grade 9].

    ERIC Educational Resources Information Center

    Parma City School District, OH.

    Part of a series of curriculum guides dealing with industrial education in junior high schools, this guide provides three units to be used in a one semester course in grade 9 on the subjects of bikes, electricity, and small engines. The section on bicycles is divided into two parts, mechanical and power (i.e. motorcycles) and covers the topics of…

  19. Structure-property relationships in Waspaloy via small angle scattering and electrical resistivity measurements

    SciTech Connect

    Whelchel, R.; Gerhardt, Dr. Rosario; Littrell, Ken

    2010-01-01

    The mechanical properties in superalloys are controlled by the distribution of the {gamma}{prime} precipitate phase. Electrical measurements have been shown to be sensitive to certain aspects of the precipitation process and show promise for predicting the evolving microstructural state in superalloys. Aging experiments were conducted on Waspaloy samples for temperatures between 600 and 950 C for times ranging from 2min to 500h. Particle size distributions were obtained by modeling of small angle scattering (SAS) data, whereas, small precipitate size information, strain, and lattice mismatch data were obtained from X-ray diffraction. The microstructural information was then used to create a figure of merit of electron scattering intended to correlate electrical properties to the precipitate microstructure. The proposed figure of merit shows an empirical correlation with the electrical resistivity data, demonstrating the sensitivity of the resistivity measurements to the precipitation process and coarsening behavior.

  20. Small Wind Electric Systems: A Guide Produced for the Tennessee Valley Authority (Revised) (Brochure)

    SciTech Connect

    Not Available

    2009-06-01

    Small Wind Electric Systems: A Guide Produced for the Tennessee Valley Authority provides consumers with information to help them determine whether a small wind electric system can provide all or a portion of the energy they need for their home or business based on their wind resource, energy needs, and their economics. Topics discussed in the guide include how to make a home more energy efficient, how to choose the correct turbine size, the parts of a wind electric system, how to determine whether enough wind resource exists, how to choose the best site for a turbine, how to connect a system to the utility grid, and whether it's possible to become independent of the utility grid using wind energy. In addition, the cover of the guide contains a regional wind resource map and a list of incentives and contacts for more information.

  1. Effect of Tributyrin on Electrical Activity in the Small Intestine during Early Postoperative Period.

    PubMed

    Tropskaya, N S; Kislyakova, E A; Popova, T S

    2015-12-01

    The effect of enteral administration of tributyrin on electrical activity in the upper segments of the small intestine was examined in rats on the model of postoperative ileus. This postoperative state is characterized with pronounced and long-term disturbances in generation of migrating myoelectric complex of the small intestine. The enteral administration of tributyrin in the early postoperative period aimed to suppress the non-adrenergic non-cholinergic influences and activation of the cholinergic anti-inflammatory pathways is an effective procedure to normalize the migrating myoelectric complex and therefore the coordinated propulsive peristalsis in the small intestine.

  2. MMS Multipoint electric field observations of small-scale magnetic holes

    NASA Astrophysics Data System (ADS)

    Goodrich, Katherine A.; Ergun, Robert E.; Wilder, Frederick D.; Burch, James; Torbert, Roy; Khotyaintsev, Yuri; Lindqvist, Per-Arne; Russell, Christopher; Strangeway, Robert; Magnes, Werner; Gershman, Daniel; Giles, Barbara; Nakamura, Rumi; Stawarz, Julia; Holmes, Justin; Sturner, Andrew; Malaspina, David M.

    2016-06-01

    Small-scale magnetic holes (MHs), local depletions in magnetic field strength, have been observed multiple times in the Earth's magnetosphere in the bursty bulk flow (BBF) braking region. This particular subset of MHs has observed scale sizes perpendicular to the background magnetic field (B) less than the ambient ion Larmor radius (ρi). Previous observations by Time History of Events and Macroscale Interactions during Substorms (THEMIS) indicate that this subset of MHs can be supported by a current driven by the E × B drift of electrons. Ions do not participate in the E × B drift due to the small-scale size of the electric field. While in the BBF braking region, during its commissioning phase, the Magnetospheric Multiscale (MMS) spacecraft observed a small-scale MH. The electric field observations taken during this event suggest the presence of electron currents perpendicular to the magnetic field. These observations also suggest that these currents can evolve to smaller spatial scales.

  3. Relativistic Bessel cylinders

    NASA Astrophysics Data System (ADS)

    Krisch, J. P.; Glass, E. N.

    2014-10-01

    A set of cylindrical solutions to Einstein's field equations for power law densities is described. The solutions have a Bessel function contribution to the metric. For matter cylinders regular on axis, the first two solutions are the constant density Gott-Hiscock string and a cylinder with a metric Airy function. All members of this family have the Vilenkin limit to their mass per length. Some examples of Bessel shells and Bessel motion are given.

  4. Indicator system provides complete data of engine cylinder pressure variation

    NASA Technical Reports Server (NTRS)

    Mc Jones, R. W.; Morgan, N. E.

    1966-01-01

    Varying reference pressure used together with a balanced pressure pickup /a diaphragm switch/ to switch the electric output of the pressure transducer in a reference pressure line obtains precise engine cylinder pressure data from a high speed internal combustion engine.

  5. Ultra-small single-negative electric metamaterials for electromagnetic coupling reduction of microstrip antenna array.

    PubMed

    Xu, He-Xiu; Wang, Guang-Ming; Qi, Mei-Qing; Zeng, Hui-Yong

    2012-09-24

    We report initially the design, fabrication and measurement of using waveguided electric metamaterials (MTM) in the design of closely-spaced microtrip antenna arrays with mutual coupling reduction. The complementary spiral ring resonators (CSRs) which exhibit single negative resonant permittivity around 3.5GHz are used as the basic electric MTM element. For verification, two CSRs with two and three concentric rings are considered, respectively. By properly arranging these well engineered waveguided MTMs between two H-plane coupled patch antennas, both numerical and measured results indicate that more than 8.4 dB mutual coupling reduction is obtained. The mechanism has been studied from a physical insight. The electric MTM element is electrically small, enabling the resultant antenna array to exhibit a small separation (λo/8 at the operating wavelength) and thus a high directivity. The proposed strategy opens an avenue to new types of antenna with super performances and can be generalized for other electric resonators. PMID:23037347

  6. Why intra-epidermal electrical stimulation achieves stimulation of small fibres selectively: a simulation study

    NASA Astrophysics Data System (ADS)

    Motogi, Jun; Sugiyama, Yukiya; Laakso, Ilkka; Hirata, Akimasa; Inui, Koji; Tamura, Manabu; Muragaki, Yoshihiro

    2016-06-01

    The in situ electric field in the peripheral nerve of the skin is investigated to discuss the selective stimulation of nerve fibres. Coaxial planar electrodes with and without intra-epidermal needle tip were considered as electrodes of a stimulator. From electromagnetic analysis, the tip depth of the intra-epidermal electrode should be larger than the thickness of the stratum corneum, the electrical conductivity of which is much lower than the remaining tissue. The effect of different radii of the outer ring electrode on the in situ electric field is marginal. The minimum threshold in situ electric field (rheobase) for free nerve endings is estimated to be 6.3 kV m-1. The possible volume for electrostimulation, which can be obtained from the in situ electric field distribution, becomes deeper and narrower with increasing needle depth, suggesting that possible stimulation sites may be controlled by changing the needle depth. The injection current amplitude should be adjusted when changing the needle depth because the peak field strength also changes. This study shows that intra-epidermal electrical stimulation can achieve stimulation of small fibres selectively, because Aβ-, Aδ-, and C-fibre terminals are located at different depths in the skin.

  7. Simulation of a small molecule analogue of a lithium ionomer in an external electric field

    SciTech Connect

    Waters, Sara M.; McCoy, John D. Brown, Jonathan R.; Frischknecht, Amalie L.

    2014-01-07

    We have investigated the ion dynamics in lithium-neutralized 2-pentylheptanoic acid, a small molecule analogue of a precise poly(ethylene-co-acrylic acid) lithium ionomer. Atomistic molecular dynamics simulations were performed in an external electric field. The electric field causes alignment of the ionic aggregates along the field direction. The energetic response of the system to an imposed oscillating electric field for a wide range of frequencies was tracked by monitoring the coulombic contribution to the energy. The susceptibility found in this manner is a component of the dielectric susceptibility typically measured experimentally. A dynamic transition is found and the frequency associated with this transition varies with temperature in an Arrhenius manner. The transition is observed to be associated with rearrangements of the ionic aggregates.

  8. Development of a new generation of small scale biomass-fueled electric generating power plants

    SciTech Connect

    Craig, J.D.; Purvis, C.R.

    1995-11-01

    There exists a need by a large worldwide market for greatly improved small scale (1 to 20 MWe per unit) biomass-fueled power plants. These power plants will significantly increase the efficiency of generating electric power from wood and bagasse as well as convert non-traditional fuel sources such as rice hulls, animal manure, cotton gin trash, straws, and grasses to electricity. Advancing the technology of biomass-fueled power plants will greatly expand the use of this environmentally friendly sustainable 24 hr-per-day source of electrical power for industry and communities worldwide. This paper briefly describes the status of a biomass-fueled power plant under development by Cratech, Inc.

  9. Modeling of sharp change in magnetic hysteresis behavior of electrical steel at small plastic deformation

    SciTech Connect

    Sablik, M.J.; Rios, S.; Landgraf, F.J.G.; Yonamine, T.; Campos, M.F. de

    2005-05-15

    In 2.2% Si electrical steel, the magnetic hysteresis behavior is sharply sheared by a rather small plastic deformation (0.5%). A modification to the Jiles-Atherton hysteresis model makes it possible to model magnetic effects of plastic deformation. In this paper, with this model, it is shown how a narrow hysteresis with an almost steplike hysteresis curve for an undeformed specimen is sharply sheared by plastic deformation. Computed coercivity and hysteresis loss show a sharp step to higher values at small strain due to an n=1/2 power law dependence on residual strain. The step is seen experimentally.

  10. Equivalent circuits for electrically small antennas using LS-decomposition with the method of moments

    NASA Astrophysics Data System (ADS)

    Simpson, T. L.; Logan, James C.; Rockway, John W.

    1989-12-01

    As part of an investigation into methods for accelerating the process of filling the method-of-moments impedance matrix (Z), it was found that (Z) could be decomposed into three parts: a real inductance matrix (L) from the magnetostatic vector potential, a real elastance (inverse capacitance) matrix (S) from the electrostatic static scalar potential, and a complex impedance matrix (z/omega/) of residual frequency-dependent contributions. By neglecting (z/omega/) at sufficiently low frequencies, static and quasi-static charge and current distributions were obtained. For electrically small antennas, a complete RLC circuit was obtained directly from a single quasi-static solution rather than as an approximate characterization of the impedance as a function of frequency. This gives a precise definition of the circuit parameters limiting the performance of electrically small antennas.

  11. The performance of solar thermal electric power systems employing small heat engines

    NASA Technical Reports Server (NTRS)

    Pons, R. L.

    1980-01-01

    The paper presents a comparative analysis of small (10 to 100 KWe) heat engines for use with a solar thermal electric system employing the point-focusing, distributed receiver (PF-DR) concept. Stirling, Brayton, and Rankine cycle engines are evaluated for a nominal overall system power level of 1 MWe, although the concept is applicable to power levels up to at least 10 MWe. Multiple concentrators are electrically connected to achieve the desired plant output. Best performance is achieved with the Stirling engine, resulting in a system Levelized Busbar Energy Cost of just under 50 mills/kWH and a Capital Cost of $900/kW, based on the use of mass-produced components. Brayton and Rankine engines show somewhat less performance but are viable alternatives with particular benefits for special applications. All three engines show excellent performance for the small community application.

  12. Disassembly properties and material characterisation of household small waste electric and electronic equipment.

    PubMed

    Bovea, María D; Pérez-Belis, Victoria; Ibáñez-Forés, Valeria; Quemades-Beltrán, Pilar

    2016-07-01

    This paper is focused on characterising small waste electric and electronic equipment, specifically small household appliances, from two different points of views: disassembly properties and material identification. The sample for this characterisation was obtained from a selective collection campaign organised in Castellón de la Plana (Spain). A total amount of 833.7kg (749 units) of small waste electric and electronic equipment was collected, of which 23.3% by weight and 22.4% by units belonged to the subcategory household equipment. This subcategory, composed of appliances such as vacuum cleaners, toasters, sandwich makers, hand blenders, juicers, coffee makers, hairdryers, scales, irons and heaters, was first disassembled in order to analyse different aspects of the disassembly process for each equipment type: type of joints, ease of identification of materials, ease of access to joints for extracting components, ease of separation of components from the whole, uniformity of tools needed for the disassembly process and possibility of reassembly after disassembly. Results show that the most common joints used in these equipment types are snap-fits and screws, although some permanent joints have also been identified. Next, the material composition of each component of each appliance belonging to each equipment type was identified visually and with additional mechanical trials and testing. It can be observed that plastic and electric/electronic components are present in all the equipment types analysed and are also the material fractions that appear with higher percentages in the material composition: 41.1wt% and 39.1wt% for the plastic fraction and electric/electronic components, respectively. The most common plastics are: polypropylene (PP), acrylonitrile butadiene styrene (ABS) and polycarbonate (PC), while the most common electric/electronic components are: cable, plug and printed circuit boards. Results also show that disassembly properties and material

  13. Performance of a Fuel-Cell-Powered, Small Electric Airplane Assessed

    NASA Technical Reports Server (NTRS)

    Berton, Jeffrey J.

    2004-01-01

    Rapidly emerging fuel-cell-power technologies may be used to launch a new revolution of electric propulsion systems for light aircraft. Future small electric airplanes using fuel cell technologies hold the promise of high reliability, low maintenance, low noise, and - with the exception of water vapor - zero emissions. An analytical feasibility and performance assessment was conducted by NASA Glenn Research Center's Airbreathing Systems Analysis Office of a fuel-cell-powered, propeller-driven, small electric airplane based on a model of the MCR-01 two-place kitplane (Dyn'Aero, Darois, France). This assessment was conducted in parallel with an ongoing effort by the Advanced Technology Products Corporation and the Foundation for Advancing Science and Technology Education. Their project - partially funded by a NASA grant - is to design, build, and fly the first manned, continuously propelled, nongliding electric airplane. In our study, an analytical performance model of a proton exchange membrane (PEM) fuel cell propulsion system was developed and applied to a notional, two-place light airplane modeled after the MCR-01 kitplane. The PEM fuel cell stack was fed pure hydrogen fuel and humidified ambient air via a small automotive centrifugal supercharger. The fuel cell performance models were based on chemical reaction analyses calibrated with published data from the fledgling U.S. automotive fuel cell industry. Electric propeller motors, rated at two shaft power levels in separate assessments, were used to directly drive a two-bladed, variable-pitch propeller. Fuel sources considered were compressed hydrogen gas and cryogenic liquid hydrogen. Both of these fuel sources provided pure, contaminant-free hydrogen for the PEM cells.

  14. Disassembly properties and material characterisation of household small waste electric and electronic equipment.

    PubMed

    Bovea, María D; Pérez-Belis, Victoria; Ibáñez-Forés, Valeria; Quemades-Beltrán, Pilar

    2016-07-01

    This paper is focused on characterising small waste electric and electronic equipment, specifically small household appliances, from two different points of views: disassembly properties and material identification. The sample for this characterisation was obtained from a selective collection campaign organised in Castellón de la Plana (Spain). A total amount of 833.7kg (749 units) of small waste electric and electronic equipment was collected, of which 23.3% by weight and 22.4% by units belonged to the subcategory household equipment. This subcategory, composed of appliances such as vacuum cleaners, toasters, sandwich makers, hand blenders, juicers, coffee makers, hairdryers, scales, irons and heaters, was first disassembled in order to analyse different aspects of the disassembly process for each equipment type: type of joints, ease of identification of materials, ease of access to joints for extracting components, ease of separation of components from the whole, uniformity of tools needed for the disassembly process and possibility of reassembly after disassembly. Results show that the most common joints used in these equipment types are snap-fits and screws, although some permanent joints have also been identified. Next, the material composition of each component of each appliance belonging to each equipment type was identified visually and with additional mechanical trials and testing. It can be observed that plastic and electric/electronic components are present in all the equipment types analysed and are also the material fractions that appear with higher percentages in the material composition: 41.1wt% and 39.1wt% for the plastic fraction and electric/electronic components, respectively. The most common plastics are: polypropylene (PP), acrylonitrile butadiene styrene (ABS) and polycarbonate (PC), while the most common electric/electronic components are: cable, plug and printed circuit boards. Results also show that disassembly properties and material

  15. Design for a Simple and Inexpensive Cylinder-within-a-Cylinder Gradient Maker for the Undergraduate Biochemistry Laboratory

    ERIC Educational Resources Information Center

    Sims, Paul A.; O'Mealey, Gary B.; Khan, Nabeel A.; Larabee, Chelsea M.

    2011-01-01

    A design for a simple and inexpensive gradient maker is described. The gradient maker is assembled by (i) cutting the tops off two plastic bottles of differing diameters to produce two cylinders with intact bottoms; (ii) drilling a small hole toward the bottom of the smaller diameter cylinder and plugging the hole with a size 00 cork stopper; and…

  16. Conformal Pad-Printing Electrically Conductive Composites onto Thermoplastic Hemispheres: Toward Sustainable Fabrication of 3-Cents Volumetric Electrically Small Antennas.

    PubMed

    Wu, Haoyi; Chiang, Sum Wai; Yang, Cheng; Lin, Ziyin; Liu, Jingping; Moon, Kyoung-Sik; Kang, Feiyu; Li, Bo; Wong, Ching Ping

    2015-01-01

    Electrically small antennas (ESAs) are becoming one of the key components in the compact wireless devices for telecommunications, defence, and aerospace systems, especially for the spherical one whose geometric layout is more closely approaching Chu's limit, thus yielding significant bandwidth improvements relative to the linear and planar counterparts. Yet broad applications of the volumetric ESAs are still hindered since the low cost fabrication has remained a tremendous challenge. Here we report a state-of-the-art technology to transfer electrically conductive composites (ECCs) from a planar mould to a volumetric thermoplastic substrate by using pad-printing technology without pattern distortion, benefit from the excellent properties of the ECCs as well as the printing-calibration method that we developed. The antenna samples prepared in this way meet the stringent requirement of an ESA (ka is as low as 0.32 and the antenna efficiency is as high as 57%), suggesting that volumetric electronic components i.e. the antennas can be produced in such a simple, green, and cost-effective way. This work can be of interest for the development of studies on green and high performance wireless communication devices. PMID:26317999

  17. Conformal Pad-Printing Electrically Conductive Composites onto Thermoplastic Hemispheres: Toward Sustainable Fabrication of 3-Cents Volumetric Electrically Small Antennas.

    PubMed

    Wu, Haoyi; Chiang, Sum Wai; Yang, Cheng; Lin, Ziyin; Liu, Jingping; Moon, Kyoung-Sik; Kang, Feiyu; Li, Bo; Wong, Ching Ping

    2015-01-01

    Electrically small antennas (ESAs) are becoming one of the key components in the compact wireless devices for telecommunications, defence, and aerospace systems, especially for the spherical one whose geometric layout is more closely approaching Chu's limit, thus yielding significant bandwidth improvements relative to the linear and planar counterparts. Yet broad applications of the volumetric ESAs are still hindered since the low cost fabrication has remained a tremendous challenge. Here we report a state-of-the-art technology to transfer electrically conductive composites (ECCs) from a planar mould to a volumetric thermoplastic substrate by using pad-printing technology without pattern distortion, benefit from the excellent properties of the ECCs as well as the printing-calibration method that we developed. The antenna samples prepared in this way meet the stringent requirement of an ESA (ka is as low as 0.32 and the antenna efficiency is as high as 57%), suggesting that volumetric electronic components i.e. the antennas can be produced in such a simple, green, and cost-effective way. This work can be of interest for the development of studies on green and high performance wireless communication devices.

  18. Conformal Pad-Printing Electrically Conductive Composites onto Thermoplastic Hemispheres: Toward Sustainable Fabrication of 3-Cents Volumetric Electrically Small Antennas

    PubMed Central

    Wu, Haoyi; Chiang, Sum Wai; Yang, Cheng; Lin, Ziyin; Liu, Jingping; Moon, Kyoung-Sik; Kang, Feiyu; Li, Bo; Wong, Ching Ping

    2015-01-01

    Electrically small antennas (ESAs) are becoming one of the key components in the compact wireless devices for telecommunications, defence, and aerospace systems, especially for the spherical one whose geometric layout is more closely approaching Chu’s limit, thus yielding significant bandwidth improvements relative to the linear and planar counterparts. Yet broad applications of the volumetric ESAs are still hindered since the low cost fabrication has remained a tremendous challenge. Here we report a state-of-the-art technology to transfer electrically conductive composites (ECCs) from a planar mould to a volumetric thermoplastic substrate by using pad-printing technology without pattern distortion, benefit from the excellent properties of the ECCs as well as the printing-calibration method that we developed. The antenna samples prepared in this way meet the stringent requirement of an ESA (ka is as low as 0.32 and the antenna efficiency is as high as 57%), suggesting that volumetric electronic components i.e. the antennas can be produced in such a simple, green, and cost-effective way. This work can be of interest for the development of studies on green and high performance wireless communication devices. PMID:26317999

  19. 4. View showing cylinder end of two, cylinder, compound Corliss ...

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

    4. View showing cylinder end of two, cylinder, compound Corliss steam engine with tandem air compressor. - International Smelting & Refining Company, Tooele Smelter, Powerhouse, State Route 178, Tooele, Tooele County, UT

  20. Combined fast multipole-QR compression technique for solving electrically small to large structures for broadband applications

    NASA Technical Reports Server (NTRS)

    Jandhyala, Vikram (Inventor); Chowdhury, Indranil (Inventor)

    2011-01-01

    An approach that efficiently solves for a desired parameter of a system or device that can include both electrically large fast multipole method (FMM) elements, and electrically small QR elements. The system or device is setup as an oct-tree structure that can include regions of both the FMM type and the QR type. An iterative solver is then used to determine a first matrix vector product for any electrically large elements, and a second matrix vector product for any electrically small elements that are included in the structure. These matrix vector products for the electrically large elements and the electrically small elements are combined, and a net delta for a combination of the matrix vector products is determined. The iteration continues until a net delta is obtained that is within predefined limits. The matrix vector products that were last obtained are used to solve for the desired parameter.

  1. Anisotropic charge and heat conduction through arrays of parallel elliptic cylinders in a continuous medium

    NASA Astrophysics Data System (ADS)

    Martin, James E.; Ribaudo, Troy

    2013-04-01

    Arrays of circular pores in silicon can exhibit a phononic bandgap when the lattice constant is smaller than the phonon scattering length, and so have become of interest for use as thermoelectric materials, due to the large reduction in thermal conductivity that this bandgap can cause. The reduction in electrical conductivity is expected to be less, because the lattice constant of these arrays is engineered to be much larger than the electron scattering length. As a result, electron transport through the effective medium is well described by the diffusion equation, and the Seebeck coefficient is expected to increase. In this paper, we develop an expression for the purely diffusive thermal (or electrical) conductivity of a composite comprised of square or hexagonal arrays of parallel circular or elliptic cylinders of one material in a continuum of a second material. The transport parallel to the cylinders is straightforward, so we consider the transport in the two principal directions normal to the cylinders, using a self-consistent local field calculation based on the point dipole approximation. There are two limiting cases: large negative contrast (e.g., pores in a conductor) and large positive contrast (conducting pillars in air). In the large negative contrast case, the transport is only slightly affected parallel to the major axis of the elliptic cylinders but can be significantly affected parallel to the minor axis, even in the limit of zero volume fraction of pores. The positive contrast case is just the opposite: the transport is only slightly affected parallel to the minor axis of the pillars but can be significantly affected parallel to the major axis, even in the limit of zero volume fraction of pillars. The analytical results are compared to extensive FEA calculations obtained using Comsol™ and the agreement is generally very good, provided the cylinders are sufficiently small compared to the lattice constant.

  2. Cylinder To Cylinder Balancing Using Intake Valve Actuation

    DOEpatents

    Duffy, Kevin P.; Kieser, Andrew J.; Kilkenny, Jonathan P.

    2005-01-18

    A method and apparatus for balancing a combustion phasing between a plurality of cylinders located in an engine. The method and apparatus includes a determining a combustion timing in each cylinder, establishing a baseline parameter for a desired combustion timing, and varying actuation of at least one of a plurality of intake valves, each intake valve being in fluid communication with a corresponding cylinder, such that the combustion timing in each cylinder is substantially equal to the desired combustion timing.

  3. Developments of a Novel Impedance Matching Circuit for Electrically Small Antennas

    NASA Astrophysics Data System (ADS)

    Yoshida, K.; Sakaguchi, S.; Oda, S.; Kanaya, H.

    2006-06-01

    In order to reduce the size of a wireless system, we have proposed the design formulas for an electrically small antenna (ESA), i.e. an antenna whose dimension is much smaller than a wavelength, with a miniaturized matching circuit which connects to a 50 ohm external circuit. We designed a slot dipole antenna with the aid of the simulations using the electrical circuits as well as the electromagnetic field (EM field) simulator. The size of the designed antenna including the matching circuit is 4.1 mm × 1.9 mm on MgO substrate with relative permittivity of 9.6 at the center frequency of 5 GHz, and the designed fractional bandwidth is 13%@RL = 3dB. We also made experiments on the slot dipole type ESA with a matching circuit using YBCO thin films on MgO substrates.

  4. Advanced fault diagnosis for the mass production of small-power electric motors

    NASA Astrophysics Data System (ADS)

    Filbert, Dieter

    1993-09-01

    High quality is a principal goal in the mass production of electric niotors (i.e. d.c. motors for cars and universal motors for house hold appliances).The processing of vibration and acoustical signals are widely used in quality assurance in the mass production but the coupling of the sensors to the motor as well as noise produced in the environment make it still difficult to get reproducible diagnostic results. High quality in production can be achieved by the powerful modern diagnostic methods which became possible because of the progress in microelectronics (microprocessors and signal processors). This progress made mathematical methods and signal processing applicable. Therefore this paper deals with diagnostic methods that use the measured signals of voltage, current and speed only but achieve a good testing. It gives an overview of new methods for the feature extraction and fault detection on small power electric motors.

  5. Induced charge electrophoresis of a conducting cylinder in a nonconducting cylindrical pore and its micromotoring application

    NASA Astrophysics Data System (ADS)

    Feng, Huicheng; Wong, Teck Neng; Che, Zhizhao

    2016-08-01

    Induced charge electrophoresis of a conducting cylinder suspended in a nonconducting cylindrical pore is theoretically analyzed and a micromotor is proposed that utilizes the cylinder rotation. The cylinder velocities are analytically obtained in the Dirichlet and the Neumann boundary conditions of the electric field on the cylindrical pore. The results show that the cylinder not only translates but also rotates when it is eccentric with respect to the cylindrical pore. The influences of a number of parameters on the cylinder velocities are characterized in detail. The cylinder trajectories show that the cylinder approaches and becomes stationary at certain positions within the cylindrical pore. The proposed micromotor is capable of working under a heavy load with a high rotational velocity when the eccentricity is large and the applied electric field is strong.

  6. Torsion of Noncircular Composite Cylinders

    NASA Technical Reports Server (NTRS)

    Rouse, Marshall; Hyer, Michael W.; Haynie, Waddy T.

    2005-01-01

    The paper presents a brief overview of the predicted deformation and failure characteristics of noncircular composite cylinders subjected to torsion. Using a numerical analysis, elliptical cylinders with a minor-to-major diameter ratio of 0.7 are considered. Counterpart circular cylinders with the same circumference as the elliptical cylinders are included for comparison. The cylinders are constructed of a medium-modulus graphite-epoxy material in a quasi-isotropic lay-up. Imperfections generated from the buckling mode shapes are included in the initial cross-sectional geometry of the cylinders. Deformations until first fiber failure, as predicted using the maximum stress failure criterion and a material degradation scheme, are presented. For increasing levels of torsion, the deformations of the elliptical cylinders, in the form of wrinkling of the cylinder wall, occur primarily in the flatter regions of the cross section. By comparison the wrinkling deformations of the circular cylinders are more uniformly distributed around the circumference. Differences in the initial failure and damage progression and the overall torque vs. twist relationship between the elliptical and circular cylinders are presented. Despite differences in the response as the cylinders are being loaded, at first fiber failure the torque and twist for the elliptical and circular cylinders nearly coincide.

  7. Technique for Solving Electrically Small to Large Structures for Broadband Applications

    NASA Technical Reports Server (NTRS)

    Jandhyala, Vikram; Chowdhury, Indranil

    2011-01-01

    Fast iterative algorithms are often used for solving Method of Moments (MoM) systems, having a large number of unknowns, to determine current distribution and other parameters. The most commonly used fast methods include the fast multipole method (FMM), the precorrected fast Fourier transform (PFFT), and low-rank QR compression methods. These methods reduce the O(N) memory and time requirements to O(N log N) by compressing the dense MoM system so as to exploit the physics of Green s Function interactions. FFT-based techniques for solving such problems are efficient for spacefilling and uniform structures, but their performance substantially degrades for non-uniformly distributed structures due to the inherent need to employ a uniform global grid. FMM or QR techniques are better suited than FFT techniques; however, neither the FMM nor the QR technique can be used at all frequencies. This method has been developed to efficiently solve for a desired parameter of a system or device that can include both electrically large FMM elements, and electrically small QR elements. The system or device is set up as an oct-tree structure that can include regions of both the FMM type and the QR type. The system is enclosed with a cube at a 0- th level, splitting the cube at the 0-th level into eight child cubes. This forms cubes at a 1st level, recursively repeating the splitting process for cubes at successive levels until a desired number of levels is created. For each cube that is thus formed, neighbor lists and interaction lists are maintained. An iterative solver is then used to determine a first matrix vector product for any electrically large elements as well as a second matrix vector product for any electrically small elements that are included in the structure. These matrix vector products for the electrically large and small elements are combined, and a net delta for a combination of the matrix vector products is determined. The iteration continues until a net delta is

  8. Small UAV Research and Evolution in Long Endurance Electric Powered Vehicles

    NASA Technical Reports Server (NTRS)

    Logan, Michael J.; Chu, Julio; Motter, Mark A.; Carter, Dennis L.; Ol, Michael; Zeune, Cale

    2007-01-01

    This paper describes recent research into the advancement of small, electric powered unmanned aerial vehicle (UAV) capabilities. Specifically, topics include the improvements made in battery technology, design methodologies, avionics architectures and algorithms, materials and structural concepts, propulsion system performance prediction, and others. The results of prototype vehicle designs and flight tests are discussed in the context of their usefulness in defining and validating progress in the various technology areas. Further areas of research need are also identified. These include the need for more robust operating regimes (wind, gust, etc.), and continued improvement in payload fraction vs. endurance.

  9. Proceedings of Small Power Systems Solar Electric Workshop. Volume 2: Invited papers

    NASA Technical Reports Server (NTRS)

    Ferber, R. (Editor)

    1978-01-01

    The focus of this work shop was to present the committment to the development of solar thermal power plants for a variety of applications including utility applications. Workshop activities included panel discussions, formal presentations, small group interactive discussions, question and answer periods, and informal gatherings. Discussion on topics include: (1) solar power technology options; (2) solar thermal power programs currently underway at the DOE, JPL, Electric Power Research Institute (EPRI), and Solar Energy Research Institute (SERI); (3) power options competing with solar; (4) institutional issues; (5) environmental and siting issues; (6) financial issues; (7) energy storage; (8) site requirements for experimental solar installations, and (9) utility planning.

  10. Estimating electric field enhancement factors on an aircraft utilizing a small scale model: A method evaluation

    NASA Technical Reports Server (NTRS)

    Easterbrook, Calvin C.; Rudolph, Terence; Easterbrook, Kevin

    1988-01-01

    A method for obtaining field enhancement factors at specific points on an aircraft utilizing a small scale model was evaluated by measuring several canonical shapes. Comparison of the form factors obtained by analytical means with measurements indicate that the experimental method has serious flaws. Errors of 200 to 300 percent were found between analytical values and measured values. As a result of the study, the analytical method is not recommended for calibration of field meters located on aircraft, and should not be relied upon in any application where the local spatial derivatives of the electric field on the model are large over the dimensions of the sensing probe.

  11. Fabrication of a 3D electrically small antenna using holographic photolithography

    NASA Astrophysics Data System (ADS)

    Toriz-Garcia, J. J.; Cowling, J. J.; Williams, G. L.; Bai, Q.; Seed, N. L.; Tennant, A.; McWilliam, R.; Purvis, A.; Soulard, F. B.; Ivey, P. A.

    2013-05-01

    We describe the novel fabrication of a 3D electrical small antenna and its subsequent characterization. The patterning of meander lines conformed onto a hemispherical substrate is achieved by 3D holographic photolithography, which uses time-division multiplexing of a series of iteratively optimized computer-generated holograms. The meander lines have a line width of 100 µm and line separation of 400 µm, with a line pitch of 500 µm and a total meander length of 145 mm. The working frequency is found to be 2.06 GHz, with an efficiency of 46%. This work demonstrates a new method for the fabrication of 3D conformal antennas.

  12. Small oscillations of a 3D electric dipole in the presence of a uniform magnetic field

    NASA Astrophysics Data System (ADS)

    del Pino, L. A.; Atenas, B.; Curilef, S.

    2016-05-01

    The classical behavior of a 3D electric dipole in the presence of a uniform magnetic field is studied in the small oscillations approximation. Using the Lagrangian formulation, the equations of motion are obtained, as well as their solutions and constants of motion. Normal modes of oscillation and their corresponding normal coordinates are obtained. Furthermore, the existence of a type of bound states without turning points, so-called trapped states conjectured by Troncoso and Curilef [Eur. J. Phys 27 (2006) 1315-1322], is investigated.

  13. Diffusion Limited Aggregation on a Cylinder

    NASA Astrophysics Data System (ADS)

    Benjamini, Itai; Yadin, Ariel

    2008-04-01

    We consider the DLA process on a cylinder G × {mathbb{N}} . It is shown that this process “grows arms”, provided that the base graph G has small enough mixing time. Specifically, if the mixing time of G is at most log^{(2-ɛ)}left\\vert G right\\vert , the time it takes the cluster to reach the m th layer of the cylinder is at most of order m \\cdot left\\vert G right\\vert/loglogleft\\vert G right\\vert . In particular we get examples of infinite Cayley graphs of degree 5, for which the DLA cluster on these graphs has arbitrarily small density. In addition, we provide an upper bound on the rate at which the “arms” grow. This bound is valid for a large class of base graphs G, including discrete tori of dimension at least 3. It is also shown that for any base graph G, the density of the DLA process on a G-cylinder is related to the rate at which the arms of the cluster grow. This implies that for any vertex transitive G, the density of DLA on a G-cylinder is bounded by 2/3.

  14. Laboratory measurements of electrical resistivity versus water content on small soil cores

    NASA Astrophysics Data System (ADS)

    Robain, H.; Camerlynck, C.; Bellier, G.; Tabbagh, A.

    2003-04-01

    The assessment of soil water content variations more and more leans on geophysical methods that are non invasive and that allow a high spatial sampling. Among the different methods, DC electrical imaging is moving forward. DC Electrical resistivity shows indeed strong seasonal variations that principally depend on soil water content variations. Nevertheless, the widely used Archie's empirical law [1], that links resistivity with voids saturation and water conductivity is not well suited to soil materials with high clay content. Furthermore, the shrinking and swelling properties of soil materials have to be considered. Hence, it is relevant to develop new laboratory experiments in order to establish a relation between electrical resistivity and water content taking into account the rheological and granulometrical specificities of soil materials. The experimental device developed in IRD laboratory allows to monitor simultaneously (i) the water content, (ii) the electrical resistivity and (iii) the volume of a small cylindrical soil core (100cm3) put in a temperature controlled incubator (30°C). It provides both the shrinkage curve of the soil core (voids volume versus water content) and the electrical resistivity versus water content curve The modelisation of the shrinkage curve gives for each moisture state the water respectively contained in macro and micro voids [2], and then allows to propose a generalized Archie's like law as following : 1/Rs = 1/Fma.Rma + 1/Fmi.Rmi and Fi = Ai/(Vi^Mi.Si^Ni) with Rs : the soil resistivity. Fma and Fmi : the so called "formation factor" for macro and micro voids, respectively. Rma and Rmi : the resistivity of the water contained in macro and micro voids, respectively. Vi : the volume of macro and micro voids, respectively. Si : the saturation of macro and micro voids, respectively. Ai, Mi and Ni : adjustment coefficients. The variations of Rmi are calculated, assuming that Rma is a constant. Indeed, the rise of ionic

  15. Simulation of Flow Around Cylinder Actuated by DBD Plasma

    NASA Astrophysics Data System (ADS)

    Wang, Yuling; Gao, Chao; Wu, Bin; Hu, Xu

    2016-07-01

    The electric-static body force model is obtained by solving Maxwell's electromagnetic equations. Based on the electro-static model, numerical modeling of flow around a cylinder with a dielectric barrier discharge (DBD) plasma effect is also presented. The flow streamlines between the numerical simulation and the particle image velocimetry (PIV) experiment are consistent. According to the numerical simulation, DBD plasma can reduce the drag coefficient and change the vortex shedding frequencies of flow around the cylinder.

  16. Flexural wave cloaking via embedded cylinders with systematically varying thicknesses.

    PubMed

    Cho, Sungjin; Yang, Wonseok; Lee, Sinyeob; Park, Junhong

    2016-06-01

    Simulations of flexural wave cloaking from multiple scattering events that are achieved by embedded cylinders in a thin plate are performed. Minimization of refraction is performed using small surrounding cylinders with varying thickness in radial and angular directions, respectively. The thickness variations render the effective wave speed lower in the radial direction and higher in the angular direction compared to the speed in the surrounding media, which results in the cloaking effect. In order to verify the feasibility of this approach, 15 layers of cylinders are placed around the blocked area. The multiple-scattering method is used to predict wave propagations and to take the interactions between cylinders into account. The effects of the thickness variation on the cloaking performance are analyzed. The results demonstrate that minimal scattering is achieved when the area of interest is surrounded by the thickness-varying cylinders. PMID:27369157

  17. Measurement of Electrical Conductivity into Tomato Cultivation Beds using Small Insertion Type Electrical Conductivity Sensor Designed for Agriculture

    NASA Astrophysics Data System (ADS)

    Kawashima, Kazuko; Futagawa, Masato; Ban, Yoshihiro; Asano, Yoshiyuki; Sawada, Kazuaki

    Our group has studied on-site monitoring sensor for agricultural field. An electrical conductivity (EC) sensor had been fabricated using Si integrated circuit technology. EC information of solutions shows ion concentrations dissolving in water, and can be used as the index of nutrient concentration for plants. So, it is important to measure EC in real time and on site. Because our EC sensor (5mm×5mm in size) is smaller than other commercial ones (several centimeters), it is easy to insert and achieve measurement in rock wool. In this study, our sensor measured long term EC values in tomato cultivation soil and rock wool medium. At first, we calibrated a relationship between output voltages and EC values on the sensor. The sensor was confirmed about enough EC measurement range from 8 to 969mS/m. In long period measurement, the sensor was confirmed about continuous operation for over five months, and intermittent measurement for over a year. In measurement in the cultivation soil, the sensor indicated that water was kept and diffused in the soil. In contrast, it was found that water diffused without keeping in it in rock wool medium. We confirmed our small EC sensor is useful for on-site monitoring and analysis of solution concentration distribution in several kinds of cultivation bed in real time.

  18. Measurement of small mechanical vibrations of brain tissue exposed to extremely-low-frequency electric fields

    SciTech Connect

    Spiegel, R.J.; Ali, J.S.; Peoples, J.F.; Joines, W.T.

    1986-01-01

    Electromagnetic fields can interact with biological tissue both electrically and mechanically. This study investigated the mechanical interaction between brain tissue and an extremely-low-frequency (ELF) electric field by measuring the resultant vibrational amplitude. The exposure cell is a section of X-band waveguide that was modified by the addition of a center conductor to form a small TEM cell within the waveguide structure. The ELF signal is applied to the center conductor of the TEM cell. The applied ELF electric field generates an electrostrictive force on the surface of the brain tissue. This force causes the tissue to vibrate at a frequency equal to twice the frequency of the applied sinusoidal signal. An X-band signal is fed through the waveguide, scattered by the vibrating sample, and detected by a phrase-sensitive receiver. Using a time-averaging spectrum analyzer, a vibration sensitivity of approximately 0.2 nmpp can be achieved. The amplitude of the brain tissue vibrational frequencies below 50 Hz; between 50 and 200 Hz resonant phenomena were observed; and above 200 Hz the amplitude fall-off is rapid.

  19. Efficient Radiation by Electrically Small Antennas made of Coupled Split-ring Resonators

    PubMed Central

    Peng, Liang; Chen, Peiwei; Wu, Aiting; Wang, Gaofeng

    2016-01-01

    In this paper, coupled split-ring resonators (SRRs) are used to construct the electrically small antennas. We show that through strong magnetic coupling, the coupled SRRs composite can oscillate at a wavelength much larger than its total size. Due to its magnetic dipole feature, the coupled SRRs composite allows the electromagnetic (EM) power to radiate and hence forms the electrically small antenna (ESA). Because of the high-Q resonance, the ESA could be easily matched to the driving circuit in the microwave region, through mutual induction approach. We also demonstrate that the radiation efficiency of such ESAs can be drastically improved if the current distribution on individual SRRs is similar, which is achievable by carefully designing the ESAs. From our simulations and experimental measurements, the ESAs’ radiation efficiency can reach up to 41%, with relative footprint of 0.05λ0 × 0.05λ0. Our approach would be an effective way to realize ESAs with high efficiency, which can be implemented on chip through the standard planar lithography. PMID:27630076

  20. Efficient Radiation by Electrically Small Antennas made of Coupled Split-ring Resonators.

    PubMed

    Peng, Liang; Chen, Peiwei; Wu, Aiting; Wang, Gaofeng

    2016-01-01

    In this paper, coupled split-ring resonators (SRRs) are used to construct the electrically small antennas. We show that through strong magnetic coupling, the coupled SRRs composite can oscillate at a wavelength much larger than its total size. Due to its magnetic dipole feature, the coupled SRRs composite allows the electromagnetic (EM) power to radiate and hence forms the electrically small antenna (ESA). Because of the high-Q resonance, the ESA could be easily matched to the driving circuit in the microwave region, through mutual induction approach. We also demonstrate that the radiation efficiency of such ESAs can be drastically improved if the current distribution on individual SRRs is similar, which is achievable by carefully designing the ESAs. From our simulations and experimental measurements, the ESAs' radiation efficiency can reach up to 41%, with relative footprint of 0.05λ0 × 0.05λ0. Our approach would be an effective way to realize ESAs with high efficiency, which can be implemented on chip through the standard planar lithography. PMID:27630076

  1. Efficient Radiation by Electrically Small Antennas made of Coupled Split-ring Resonators.

    PubMed

    Peng, Liang; Chen, Peiwei; Wu, Aiting; Wang, Gaofeng

    2016-09-15

    In this paper, coupled split-ring resonators (SRRs) are used to construct the electrically small antennas. We show that through strong magnetic coupling, the coupled SRRs composite can oscillate at a wavelength much larger than its total size. Due to its magnetic dipole feature, the coupled SRRs composite allows the electromagnetic (EM) power to radiate and hence forms the electrically small antenna (ESA). Because of the high-Q resonance, the ESA could be easily matched to the driving circuit in the microwave region, through mutual induction approach. We also demonstrate that the radiation efficiency of such ESAs can be drastically improved if the current distribution on individual SRRs is similar, which is achievable by carefully designing the ESAs. From our simulations and experimental measurements, the ESAs' radiation efficiency can reach up to 41%, with relative footprint of 0.05λ0 × 0.05λ0. Our approach would be an effective way to realize ESAs with high efficiency, which can be implemented on chip through the standard planar lithography.

  2. Efficient Radiation by Electrically Small Antennas made of Coupled Split-ring Resonators

    NASA Astrophysics Data System (ADS)

    Peng, Liang; Chen, Peiwei; Wu, Aiting; Wang, Gaofeng

    2016-09-01

    In this paper, coupled split-ring resonators (SRRs) are used to construct the electrically small antennas. We show that through strong magnetic coupling, the coupled SRRs composite can oscillate at a wavelength much larger than its total size. Due to its magnetic dipole feature, the coupled SRRs composite allows the electromagnetic (EM) power to radiate and hence forms the electrically small antenna (ESA). Because of the high-Q resonance, the ESA could be easily matched to the driving circuit in the microwave region, through mutual induction approach. We also demonstrate that the radiation efficiency of such ESAs can be drastically improved if the current distribution on individual SRRs is similar, which is achievable by carefully designing the ESAs. From our simulations and experimental measurements, the ESAs’ radiation efficiency can reach up to 41%, with relative footprint of 0.05λ0 × 0.05λ0. Our approach would be an effective way to realize ESAs with high efficiency, which can be implemented on chip through the standard planar lithography.

  3. Effects of a small electric current on sterilization of a dental unit water line.

    PubMed

    Tanahashi, Takayuki; Tonami, Ken-ichi; Araki, Kouji; Kurosaki, Norimasa

    2006-06-01

    In the present study, water was circulated in a simulated dental unit water line with electrifying a small current. The morphology of the biofilm developed on inner surface of the water line and the number of heterotrophic bacteria were investigated to elucidate the effect of a low level electric current on the biofilms formation associated with bacteria reproduction. Destruction and malconformation of biofilms by electrification was observed using SEM, in addition to deformation and hypertrophy of the bacteria. By naked eye observation, small pieces, which were possibly exfoliated biofilms, were detected in electrified water. While an adherent, yellow gel was demonstrated on the inner surface of the water line without electrification. With electrification, the number of bacteria decreased during the first week, however the bacteria increased gradually after that. The number of bacteria without electrification was consistently greater than that with electrification and the difference was statistically significant (P<0.05). The predominant bacteria were identified as Sphingomonas paucimobilis. The excess chlorine levels decreased to a minimum value within one week. The small current appeared to have effects on biofilm formation of heterotrophic bacteria that resulted in enhanced chlorine sterilization of dental unit water. Thus, electrification has considerable potential for the extermination of bacterial biofilms in dental unit water lines.

  4. Control of electromagnetic edge effects in electrically-small rectangular plasma reactors

    SciTech Connect

    Trampel, Christopher P.; Stieler, Daniel S.

    2012-09-15

    Electromagnetic fields supported by rectangular reactors for plasma enhanced chemical vapor deposition are studied theoretically. Expressions for the fields in an electrically-small rectangular reactor with plasma in the chamber are derived. Modal field decompositions are employed under the homogeneous plasma slab approximation. The amplitude of each mode is determined analytically. It is shown that the field can be represented by the standing wave, evanescent waves tied to the edges, and an evanescent wave tied to the corners of the reactor. The impact of boundary conditions at the plasma edge on nonuniformity is quantified. Uniformity may be improved by placing a lossy magnetic layer on the reactor sidewalls. It is demonstrated that nonuniformity is a decreasing function of layer thickness.

  5. Improved measurements of the apparent resistivity for small depths in Vertical Electrical Soundings

    NASA Astrophysics Data System (ADS)

    Faleiro, E.; Asensio, G.; Moreno, J.

    2016-08-01

    In this work, a full simulation of a Vertical Electrical Sounding of a multilayer soil using a Wenner array is performed when both the active and the measurement electrodes consist of bare rod length L buried vertically at ground level. The apparent resistivity is calculated for a wide range of values of the separation between the electrodes using the values of the potential between the measuring electrode and a proposed function that characterizes the behavior of the electrodes used which substantially improves the measurements for small depths. The results allow comparing the values of apparent resistivity obtained by known calculation expressions with the results found by using a characteristic function of the electrodes, which is proposed in this paper. In order to obtain a complete vertical sounding of the soil, the convenience of using adapted methods to the type of electrode used in the sounding is discussed.

  6. Flow control simulations around a circular cylinder by a finite-volume scheme

    NASA Astrophysics Data System (ADS)

    Lin, San-Yih; Wu, Tsuen-Muh

    1993-07-01

    A numerical study is made of the flow past a circular cylinder with/without flow control devices. The Reynolds number ranges from 20 to 200. The numerical method for the solutions of the incompressible Navier-Stokes equations is based on an artificial compressibility approach and an upwind finite-volume method. Two kinds of the flow control devices are investigated: (1) placing an attached or a detached splitter plate in the wake behind the circular cylinder, and (2) placing a second small cylinder (control cylinder) behind the circular cylinder. The numerical investigations show that both of two are effective on the suppression of vortex shedding and the reduction of drag.

  7. Potential reuse of small household waste electrical and electronic equipment: Methodology and case study.

    PubMed

    Bovea, María D; Ibáñez-Forés, Valeria; Pérez-Belis, Victoria; Quemades-Beltrán, Pilar

    2016-07-01

    This study proposes a general methodology for assessing and estimating the potential reuse of small waste electrical and electronic equipment (sWEEE), focusing on devices classified as domestic appliances. Specific tests for visual inspection, function and safety have been defined for ten different types of household appliances (vacuum cleaner, iron, microwave, toaster, sandwich maker, hand blender, juicer, boiler, heater and hair dryer). After applying the tests, reuse protocols have been defined in the form of easy-to-apply checklists for each of the ten types of appliance evaluated. This methodology could be useful for reuse enterprises, since there is a lack of specific protocols, adapted to each type of appliance, to test its potential of reuse. After applying the methodology, electrical and electronic appliances (used or waste) can be segregated into three categories: the appliance works properly and can be classified as direct reuse (items can be used by a second consumer without prior repair operations), the appliance requires a later evaluation of its potential refurbishment and repair (restoration of products to working order, although with possible loss of quality) or the appliance needs to be finally discarded from the reuse process and goes directly to a recycling process. Results after applying the methodology to a sample of 87.7kg (96 units) show that 30.2% of the appliances have no potential for reuse and should be diverted for recycling, while 67.7% require a subsequent evaluation of their potential refurbishment and repair, and only 2.1% of them could be directly reused with minor cleaning operations. This study represents a first approach to the "preparation for reuse" strategy that the European Directive related to Waste Electrical and Electronic Equipment encourages to be applied. However, more research needs to be done as an extension of this study, mainly related to the identification of the feasibility of repair or refurbishment operations.

  8. Potential reuse of small household waste electrical and electronic equipment: Methodology and case study.

    PubMed

    Bovea, María D; Ibáñez-Forés, Valeria; Pérez-Belis, Victoria; Quemades-Beltrán, Pilar

    2016-07-01

    This study proposes a general methodology for assessing and estimating the potential reuse of small waste electrical and electronic equipment (sWEEE), focusing on devices classified as domestic appliances. Specific tests for visual inspection, function and safety have been defined for ten different types of household appliances (vacuum cleaner, iron, microwave, toaster, sandwich maker, hand blender, juicer, boiler, heater and hair dryer). After applying the tests, reuse protocols have been defined in the form of easy-to-apply checklists for each of the ten types of appliance evaluated. This methodology could be useful for reuse enterprises, since there is a lack of specific protocols, adapted to each type of appliance, to test its potential of reuse. After applying the methodology, electrical and electronic appliances (used or waste) can be segregated into three categories: the appliance works properly and can be classified as direct reuse (items can be used by a second consumer without prior repair operations), the appliance requires a later evaluation of its potential refurbishment and repair (restoration of products to working order, although with possible loss of quality) or the appliance needs to be finally discarded from the reuse process and goes directly to a recycling process. Results after applying the methodology to a sample of 87.7kg (96 units) show that 30.2% of the appliances have no potential for reuse and should be diverted for recycling, while 67.7% require a subsequent evaluation of their potential refurbishment and repair, and only 2.1% of them could be directly reused with minor cleaning operations. This study represents a first approach to the "preparation for reuse" strategy that the European Directive related to Waste Electrical and Electronic Equipment encourages to be applied. However, more research needs to be done as an extension of this study, mainly related to the identification of the feasibility of repair or refurbishment operations

  9. Recycling-oriented characterization of small waste electrical and electronic equipment.

    PubMed

    Chancerel, Perrine; Rotter, Susanne

    2009-08-01

    As a result of the continuous change in the design and function of consumer electrical and electronic products, the mechanical and material properties of the obsolete products, called waste electric and electronic equipment (WEEE), are highly variable. The variability within WEEE is explained by the number of different appliances, and the heterogeneity in composition of any given appliance. This paper reports on an extended investigation of the properties of WEEE, in particular small appliances. The investigation focuses on the analysis of the composition of about 700 single appliances. Firstly, analytical methods to characterize the waste equipment are described. The results of the experimental analyses show that the mechanical properties, the material composition, the polymer composition and the chemical composition of WEEE vary not only between equipment types with different functions, but also between single appliances within one equipment type. Data on hazardous and valuable substances in selected equipment types are presented. Using detailed data on the composition of individual appliances to calculate rates of recovery for assumed recycling processes demonstrates that the performance of recycling processes depends strongly on the composition of WEEE. Recycling-oriented characterization is, therefore, a systematic approach to support the design and the operation of recycling processes.

  10. Gravity flow operated small electricity generator retrofit kit to flour mill industry.

    PubMed

    Shekara, Prithivi; Kumar V, Pavan; Hosamane, Gangadharappa Gundabhakthara

    2013-10-01

    Flour milling is a grinding process to produce flour from wheat through comprehensive stages of grinding and separation. The primary energy is required to provide power used in grinding of wheat. In wheat milling, tempering is the process of adding water to wheat before milling to toughen the bran and mellow the endosperm. Gravity flow of the wheat is utilized to rotate the dampener wheel with cups to add water. Low cost gravity flow operated small electricity generator retrofit kit for dampener was designed and developed to justify low cost energy production without expensive solutions. Results of statistical analysis indicated that there was significant difference in mean values for voltage, rpm and flow rate at the 95% probability level. The resulted maximum mechanical power and measured electrical power were 5.1 W and 4.9 W respectively at wheat flow rate of 1.6 Kg/s and dampener wheel rotational velocity of 4.4 rad/s. PMID:24426010

  11. Theory of small-scale density and electric field fluctuations in the nightside Venus ionosphere

    NASA Technical Reports Server (NTRS)

    Huba, J. D.

    1992-01-01

    Recently, it has been reported that small-scale (lambda about 0.1-2 km) density irregularities occur during 100-Hz electric field bursts in the nightside ionosphere of Venus. This paper provides a detailed analysis of the lower-hybrid-drift instability as a mechanism to generate the observed irregularities. A fully electromagnetic theory is developed that is relevant to the finite beta plasma in Venus's ionosphere and includes collisional effects (e.g., electron-ion, electron-neutral, and ion-neutral collisions). The key features of the analysis that favor this instability are the following: (1) it is a flute mode and propagates orthogonal to the ambient magnetic field; (2) it is a relatively short wavelength mode and the Doppler-shifted frequency can be greater than about 100 Hz; (3) it can produce both electric field and density fluctuations, as well as magnetic field fluctuations in a finite beta plasma; and (4) it is most unstable in low-beta plasmas so that it is likely to occur in the low-density, high-magnetic-field ionospheric holes. These features are consistent with observational results.

  12. Wake Modes and Heat Transfer from Rotationally Oscillating Cylinder

    NASA Astrophysics Data System (ADS)

    Sellappan, Prabu; Pottebaum, Tait

    2012-11-01

    Wake formation is an important problem in engineering due to its effect on phenomena such as vortex induced vibrations and heat transfer. While prior work has focused on the wake formation due to vortex shedding from stationary and oscillating cylinders, limited information is available on the relationship between wake modes and heat transfer from rotationally oscillating cylinders. Experiments were carried out at Re=150 and 750, using an electrically heated cylinder, in a water tunnel for oscillation frequencies from 0.67 to 3.5 times the natural shedding frequency and peak-to-peak oscillation amplitudes up to 320. DPIV was used to identify and map wake modes to various regions of the parameter space. Temperature data from a thermocouple embedded in the cylinder was used to calculate heat transfer rates. Correlation between heat transfer enhancement and certain wake mode regions were observed in the parameter space. The relationship between wake formation and heat transfer enhancement will be described.

  13. Small scale monitoring of a bioremediation barrier using miniature electrical resistivity tomography

    NASA Astrophysics Data System (ADS)

    Sentenac, Philippe; Hogson, Tom; Keenan, Helen; Kulessa, Bernd

    2015-04-01

    The aim of this study was to assess, in the laboratory, the efficiency of a barrier of oxygen release compound (ORC) to block and divert a diesel plume migration in a scaled aquifer model using miniature electrical resistivity tomography (ERT) as the monitoring system. Two plumes of contaminant (diesel) were injected in a soil model made of local sand and clay. The diesel plumes migration was imaged and monitored using a miniature resistivity array system that has proved to be accurate in soil resistivity variations in small-scaled models of soil. ERT results reflected the lateral spreading and diversion of the diesel plumes in the unsaturated zone. One of the contaminant plumes was partially blocked by the ORC barrier and a diversion and reorganisation of the diesel in the soil matrix was observed. The technique of time-lapse ERT imaging showed that a dense non-aqueous phase liquid (DNAPL) contaminant like diesel can be monitored through a bioremediation barrier and the technique is well suited to monitor the efficiency of the barrier. Therefore, miniature ERT as a small-scale modelling tool could complement conventional techniques, which require more expensive and intrusive site investigation prior to remediation.

  14. 15. CYLINDER DETAILS; DETAILS OF STEEL FOR CYLINDERS NO. 50 ...

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

    15. CYLINDER DETAILS; DETAILS OF STEEL FOR CYLINDERS NO. 50 (PIER 5) AND NO. 66 (PIER 6), DWG. 83, CH BY AF, ECL, APPROVED BY O.F. LACKEY, MAY 18, 1908 - Baltimore Inner Harbor, Pier 5, South of Pratt Street between Market Place & Concord Street, Baltimore, Independent City, MD

  15. 10. CYLINDER DETAILS: DETAIL OF STEEL FOR CYLINDER NO. 59, ...

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

    10. CYLINDER DETAILS: DETAIL OF STEEL FOR CYLINDER NO. 59, PIER NO. 6, DWG. 86, 3/4" = 1', MADE BY A.F., CHECKED BY E.C.L., APPROVED BY O.F. LACKEY, JUNE 2, 1908 - Baltimore Inner Harbor, Pier 6, South of Pratt Street between Concord Street & Jones Falls outlet, Baltimore, Independent City, MD

  16. Neural network control of a parallel hybrid-electric propulsion system for a small unmanned aerial vehicle

    NASA Astrophysics Data System (ADS)

    Harmon, Frederick G.

    2005-11-01

    Parallel hybrid-electric propulsion systems would be beneficial for small unmanned aerial vehicles (UAVs) used for military, homeland security, and disaster-monitoring missions. The benefits, due to the hybrid and electric-only modes, include increased time-on-station and greater range as compared to electric-powered UAVs and stealth modes not available with gasoline-powered UAVs. This dissertation contributes to the research fields of small unmanned aerial vehicles, hybrid-electric propulsion system control, and intelligent control. A conceptual design of a small UAV with a parallel hybrid-electric propulsion system is provided. The UAV is intended for intelligence, surveillance, and reconnaissance (ISR) missions. A conceptual design reveals the trade-offs that must be considered to take advantage of the hybrid-electric propulsion system. The resulting hybrid-electric propulsion system is a two-point design that includes an engine primarily sized for cruise speed and an electric motor and battery pack that are primarily sized for a slower endurance speed. The electric motor provides additional power for take-off, climbing, and acceleration and also serves as a generator during charge-sustaining operation or regeneration. The intelligent control of the hybrid-electric propulsion system is based on an instantaneous optimization algorithm that generates a hyper-plane from the nonlinear efficiency maps for the internal combustion engine, electric motor, and lithium-ion battery pack. The hyper-plane incorporates charge-depletion and charge-sustaining strategies. The optimization algorithm is flexible and allows the operator/user to assign relative importance between the use of gasoline, electricity, and recharging depending on the intended mission. A MATLAB/Simulink model was developed to test the control algorithms. The Cerebellar Model Arithmetic Computer (CMAC) associative memory neural network is applied to the control of the UAVs parallel hybrid-electric

  17. Locomotion gaits of a rotating cylinder pair

    NASA Astrophysics Data System (ADS)

    van Rees, Wim M.; Novati, Guido; Koumoutsakos, Petros; Mahadevan, L.

    2015-11-01

    Using 2D numerical simulations of the Navier-Stokes equations, we demonstrate that a simple pair of rotating cylinders can display a range of locomotion patterns of biological and engineering interest. Steadily counter-rotating the cylinders causes the pair to move akin to a vortex dipole for low rotation rates, but as the rotational velocity is increased the direction of motion reverses. Unsteady rotations lead to different locomotion gaits that resemble jellyfish (for in-phase rotations) and undulating swimmers (for out-of-phase rotations). The small number of parameters for this simple system allows us to systematically map the phase space of these gaits, and allows us to understand the underlying physical mechanisms using a minimal model with implications for biological locomotion and engineered analogs.

  18. Anomalous magnetoresistance in magnetized topological insulator cylinders

    NASA Astrophysics Data System (ADS)

    Siu, Zhuo Bin; Jalil, Mansoor B. A.

    2015-05-01

    The close coupling between the spin and momentum degrees of freedom in topological insulators (TIs) presents the opportunity for the control of one to manipulate the other. The momentum can, for example, be confined on a curved surface and the spin influenced by applying a magnetic field. In this work, we study the surface states of a cylindrical TI magnetized in the x direction perpendicular to the cylindrical axis lying along the z direction. We show that a large magnetization leads to an upwards bending of the energy bands at small |kz| . The bending leads to an anomalous magnetoresistance where the transmission between two cylinders magnetized in opposite directions is higher than when the cylinders are magnetized at intermediate angles with respect to each other.

  19. Anomalous magnetoresistance in magnetized topological insulator cylinders

    SciTech Connect

    Siu, Zhuo Bin; Jalil, Mansoor B. A.

    2015-05-07

    The close coupling between the spin and momentum degrees of freedom in topological insulators (TIs) presents the opportunity for the control of one to manipulate the other. The momentum can, for example, be confined on a curved surface and the spin influenced by applying a magnetic field. In this work, we study the surface states of a cylindrical TI magnetized in the x direction perpendicular to the cylindrical axis lying along the z direction. We show that a large magnetization leads to an upwards bending of the energy bands at small |k{sub z}|. The bending leads to an anomalous magnetoresistance where the transmission between two cylinders magnetized in opposite directions is higher than when the cylinders are magnetized at intermediate angles with respect to each other.

  20. ANFO cylinder tests

    SciTech Connect

    Davis, L. L.; Hill, L. G.

    2001-01-01

    Cylinder test data is reported for commercially available prilled ANFO (ammonium-nitrate/fuel-oil) at 0.93 ,g/cc density and ambient temperature. The tests were four-inch inner diameter, with wall-thickness and length scaled from the standard one-inch test (0.4 inch and 48 inch, respectively). The wall expansion was measured with a rotating mirror streak camera and the velocity was measured by fine-wire pin switches, in the standard manner. The wall expansion trajectory is much smoother than for conventional explosives, which show a pronounced jump-off with subs uent ring-up. This observation is consistent with a broadened detohation shock in the granular bed. ?he data is analyzed for equation-of-state information and JWL parameters are given.

  1. ANFO Cylinder Tests

    NASA Astrophysics Data System (ADS)

    Davis, L. L.; Hill, L. G.

    2002-07-01

    Cylinder test data is reported for commercially available prilled ANFO (ammonium-nitrate/fuel-oil) at 0.93 g/cc density and ambient temperature. The tests were four-inch inner diameter, with wall-thickness and length scaled from the standard one-inch test (0.4 inch and 48 inch, respectively). The wall expansion was measured with a rotating mirror streak camera and the velocity was measured by fine-wire pin switches, in the standard manner. The wall expansion trajectory is much smoother than for conventional explosives, which show a pronounced jump-off with subsequent ring-up. This observation is consistent with a broadened detonation shock in the granular bed. The data is analyzed for equation-of-state information and JWL parameters are given.

  2. ANFO Cylinder Tests

    NASA Astrophysics Data System (ADS)

    Davis, Lloyd; Hill, Larry

    2001-06-01

    Cylinder test data is reported for commercially available prilled ANFO (ammonium nitrate - fuel oil) at ca. 0.93 g/cc density and ambient temperature. The tests were four-inch inner diameter, with wall-thickness and length scaled from the standard one-inch test (0.4 inch and 48 inch, respectively). The wall expansion was measured with a rotating mirror streak camera and the velocity was measured by fine-wire pin switches, in the standard manner. The wall expansion trajectory is much smoother than for conventional explosives, which show a pronounced jump-off with subsequent ring-up. This observation is indicative of an extended reaction zone. The data is analyzed for equation-of-state information and JWL parameters are given.

  3. Low cost venom extractor based on Arduino(®) board for electrical venom extraction from arthropods and other small animals.

    PubMed

    Besson, Thomas; Debayle, Delphine; Diochot, Sylvie; Salinas, Miguel; Lingueglia, Eric

    2016-08-01

    Extracting venom from small species is usually challenging. We describe here an affordable and versatile electrical venom extractor based on the Arduino(®) Mega 2560 Board, which is designed to extract venom from arthropods and other small animals. The device includes fine tuning of stimulation time and voltage. It was used to collect venom without apparent deleterious effects, and characterized for the first time the venom of Zoropsis spinimana, a common spider in French Mediterranean regions. PMID:27158113

  4. Low cost venom extractor based on Arduino(®) board for electrical venom extraction from arthropods and other small animals.

    PubMed

    Besson, Thomas; Debayle, Delphine; Diochot, Sylvie; Salinas, Miguel; Lingueglia, Eric

    2016-08-01

    Extracting venom from small species is usually challenging. We describe here an affordable and versatile electrical venom extractor based on the Arduino(®) Mega 2560 Board, which is designed to extract venom from arthropods and other small animals. The device includes fine tuning of stimulation time and voltage. It was used to collect venom without apparent deleterious effects, and characterized for the first time the venom of Zoropsis spinimana, a common spider in French Mediterranean regions.

  5. 49 CFR 178.55 - Specification 4B240ET welded or brazed cylinders.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... cylinder made from electric resistance welded tubing. The maximum water capacity of this cylinder is 12... used. Plain carbon steel content may not exceed the following: Carbon, 0.25; phosphorus, 0.045; sulfur...) The test must be by water-jacket, or other suitable method, operated so as to obtain accurate...

  6. 49 CFR 178.55 - Specification 4B240ET welded or brazed cylinders.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... cylinder made from electric resistance welded tubing. The maximum water capacity of this cylinder is 12... used. Plain carbon steel content may not exceed the following: Carbon, 0.25; phosphorus, 0.045; sulfur...) The test must be by water-jacket, or other suitable method, operated so as to obtain accurate...

  7. 49 CFR 178.55 - Specification 4B240ET welded or brazed cylinders.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... cylinder made from electric resistance welded tubing. The maximum water capacity of this cylinder is 12... used. Plain carbon steel content may not exceed the following: Carbon, 0.25; phosphorus, 0.045; sulfur...) The test must be by water-jacket, or other suitable method, operated so as to obtain accurate...

  8. Guided resonances on lithium niobate for extremely small electric field detection investigated by accurate sensitivity analysis.

    PubMed

    Qiu, Wentao; Ndao, Abdoulaye; Lu, Huihui; Bernal, Maria-Pilar; Baida, Fadi Issam

    2016-09-01

    We present a theoretical study of guided resonances (GR) on a thin film lithium niobate rectangular lattice photonic crystal by band diagram calculations and 3D Finite Difference Time Domain (FDTD) transmission investigations which cover a broad range of parameters. A photonic crystal with an active zone as small as 13μm×13μm×0.7μm can be easily designed to obtain a resonance Q value in the order of 1000. These resonances are then employed in electric field (E-field) sensing applications exploiting the electro optic (EO) effect of lithium niobate. A local field factor that is calculated locally for each FDTD cell is proposed to accurately estimate the sensitivity of GR based E-field sensor. The local field factor allows well agreement between simulations and reported experimental data therefore providing a valuable method in optimizing the GR structure to obtain high sensitivities. When these resonances are associated with sub-picometer optical spectrum analyzer and high field enhancement antenna design, an E-field probe with a sensitivity of 50 μV/m could be achieved. The results of our simulations could be also exploited in other EO based applications such as EEG (Electroencephalography) or ECG (Electrocardiography) probe and E-field frequency detector with an 'invisible' probe to the field being detected etc. PMID:27607627

  9. Small Solar Electric Propulsion Spacecraft Concept for Near Earth Object and Inner Solar System Missions

    NASA Technical Reports Server (NTRS)

    Lang, Jared J.; Randolph, Thomas M.; McElrath, Timothy P.; Baker, John D.; Strange, Nathan J.; Landau, Damon; Wallace, Mark S.; Snyder, J. Steve; Piacentine, Jamie S.; Malone, Shane; Bury, Kristen M.; Tracy, William H.

    2011-01-01

    Near Earth Objects (NEOs) and other primitive bodies are exciting targets for exploration. Not only do they provide clues to the early formation of the universe, but they also are potential resources for manned exploration as well as provide information about potential Earth hazards. As a step toward exploration outside Earth's sphere of influence, NASA is considering manned exploration to Near Earth Asteroids (NEAs), however hazard characterization of a target is important before embarking on such an undertaking. A small Solar Electric Propulsion (SEP) spacecraft would be ideally suited for this type of mission due to the high delta-V requirements, variety of potential targets and locations, and the solar energy available in the inner solar system.Spacecraft and mission trades have been performed to develop a robust spacecraft design that utilizes low cost, off-the-shelf components that could accommodate a suite of different scientific payloads for NEO characterization. Mission concepts such as multiple spacecraft each rendezvousing with different NEOs, single spacecraft rendezvousing with separate NEOs, NEO landers, as well as other inner solar system applications (Mars telecom orbiter) have been evaluated. Secondary launch opportunities using the Expendable Secondary Payload Adapter (ESPA) Grande launch adapter with unconstrained launch dates have also been examined.

  10. Metamaterial loading of electrically small patch antennas to enable beam steering up to the horizon

    NASA Astrophysics Data System (ADS)

    Pai Raikar, Vandita Rajiv

    This thesis research has been conducted with an aim of investigating the effects of metamaterials on microstrip patch antennas. Metamaterials exhibit interesting properties such as single negative or simultaneous double negative values of relative permittivity and permeability, due to which they have gained immense popularity. The influence of metamaterials on traditional patch antennas has been a topic of focus throughout this research. Different metamaterial unit cells have been designed to possess satisfactory behavior in terms of permittivity and permeability. The use of metamaterials as a substrate for patch antennas has been explored, highlighting the possibility of designing electrically small patch antennas. Several metamaterial unit cells and modified patch antennas have been designed and modeled in Ansys HFSS, a highly competent full wave electromagnetic solver. On achieving a satisfactory results from a single patch antenna, the same concept has been applied to design a planar phased array patch antenna having 8x8 elements. The planar phased array antenna will be designed to enable beam steering from broadside toward the horizon.

  11. Sistemas Eolicos Pequenos para Generacion de Electridad (Spanish version of Small Wind Electric Systems: A U.S. Consumer's Guide)

    SciTech Connect

    Not Available

    2005-07-01

    This Spanish version of the popular Small Wind Electric Systems: A U.S. Consumer's Guide provides consumers with information to help them determine whether a small wind electric system can provide all or a portion of the energy they need for their home or business based on their wind resource, energy needs, and economics. Topics include how to make a home more energy efficient, how to choose the correct turbine size, the parts of a wind electric system, how to determine whether enough wind resource exists, how to choose the best site for a turbine, how to connect a system to the utility grid, and whether it's possible to become independent of the utility grid using wind energy. In addition, the cover of the guide contains a list of contacts for more information.

  12. Microwave heating and joining of ceramic cylinders: A mathematical model

    NASA Technical Reports Server (NTRS)

    Booty, Michael R.; Kriegsmann, Gregory A.

    1994-01-01

    A thin cylindrical ceramic sample is placed in a single mode microwave applicator in such a way that the electric field strength is allowed to vary along its axis. The sample can either be a single rod or two rods butted together. We present a simple mathematical model which describes the microwave heating process. It is built on the assumption that the Biot number of the material is small, and that the electric field is known and uniform throughout the cylinder's cross-section. The model takes the form of a nonlinear parabolic equation of reaction-diffusion type, with a spatially varying reaction term that corresponds to the spatial variation of the electromagnetic field strength in the waveguide. The equation is analyzed and a solution is found which develops a hot spot near the center of the cylindrical sample and which then propagates outwards until it stabilizes. The propagation and stabilization phenomenon concentrates the microwave energy in a localized region about the center where elevated temperatures may be desirable.

  13. Stresses in and General Instability of Monocoque Cylinders with Cutouts I : Experimental Investigation of Cylinders with a Symmetric Cutout Subjected to Pure Bending

    NASA Technical Reports Server (NTRS)

    Hoff, N J; Boley, Bruno A

    1946-01-01

    Ten 24S-T alclad cylinders of 20-inch diameter, 45- or 58-inch length, and 0.012-inch wall thickness, reinforced with 24S-T aluminum alloy stringers and rings were tested in pure bending. In the middle of the compression side of the cylinders there was a cutout extending over 19 inches in the longitudinal direction, and over an angle of 45 degrees, 90 degrees, or 135 degrees in the circumferential direction. The strain in the stringers and in the sheet covering was measured with metal electric strain gages. The stress distribution in the cylinders deviate considerably from the linear law valid for cylinders without a cutout. The maximum strain measured was about four-thirds of the value calculated from the Mc/I formula when I was taken as the moment of inertia of the cross section of the portion of the cylinder where the cutout was situated. A diagram is presented containing the strain factors defined as the ratios of measured strain to strain calculated with the Mc/I formula. All the 10 cylinders tested failed in general instability. Two symmetric and one antisymmetric pattern of buckling were observed and the buckling load appeared to be independent of the method of manufacture and the length of the cylinder. The buckling load of the cylinders having cutouts extending over 45 degrees, 90 degrees, and 135 degrees was 66, 47, and 31 percent, respectively, of the buckling load of the cylinder without a cutout.

  14. Development of Electrothermal Pulsed Plasma Thrusters for Osaka-Institute-of-Technology Electric-Rocket-Engine onboard Small Space Ship

    SciTech Connect

    Ishii, Yushuke; Yamamoto, Tsuyoshi; Yamada, Minetsugu; Tahara, Hirokazu

    2008-12-31

    The Project of Osaka-Institute-of-Technology Electric-Rocket-Engine onboard Small Space Ship (PROITERES) was started at Osaka Institute of Technology. In PROITERES, a 10-kg small satellite with electrothermal pulsed plasma thrusters (PPTs), named JOSHO, will be launched in 2010. The main mission is powered flight of small satellite by electric thruster itself. Electrothermal PPTs were studied with both experiments and numerical simulations. An electrothermal PPT with a side-fed propellant feeding mechanism achieved a total impulse of 3.6 Ns with a repetitive 10000-shot operation. An unsteady numerical simulation showed the existence of considerable amount of ablation delaying to the discharge. However, it was also shown that this phenomenon should not be regarded as the 'late time ablation' for electrothermal PPTs.

  15. Wave propagation in poroelastic hollow cylinder immersed in fluid with seismoelectric effect

    NASA Astrophysics Data System (ADS)

    Gao, Wenyang; Cui, Zhiwen; Wang, Kexie

    2013-09-01

    Based on Pride theory, we studied the propagation of seismoelectric waves in a fluid-filled poroelastic hollow cylinder. We presented the expressions of seismoelectric waves in the poroelastic hollow cylinder, acoustic and electromagnetic field in inner and outer of the hollow cylinder, and we used the boundary condition to determine acoustic and electromagnetic field. Also this problem is accomplished by using the quasi-static method. The numerical simulation is operated on acoustic field and electromagnetic field in inner fluid of hollow poroelastic cylinder, and the transient waveform is obtained. It shows that there is no difference on the graph between the electric field obtained from Pride equations and that obtained from quasi-static method. The influence of hollow cylinder thickness, molarity and permeability on wave amplitude are discussed. The results show that for the acoustic field the amplitude of longitudinal mode and Stoneley wave will increase with hollow cylinder thickness increasing, and for the converted axial electric field the amplitude of Stoneley wave increases with hollow cylinder thickness increasing, while the amplitude of longitudinal mode will decrease. The amplitude of electric field in inner fluid will decrease with the molarity of fluid increasing. The amplitude of the fluid acoustic and electric field will decrease with the permeability increasing. The influence of impermeable outer surface on the amplitude of longitudinal wave is obviously much larger than that of Stoneley wave in the electric field.

  16. Axial cylinder internal combustion engine

    SciTech Connect

    Gonzalez, C.

    1992-03-10

    This patent describes improvement in a barrel type internal combustion engine including an engine block having axial-positioned cylinders with reciprocating pistons arranged in a circular pattern: a drive shaft concentrically positioned within the cylinder block having an offset portion extending outside the cylinder block; a wobble spider rotatably journaled to the offset portion; connecting rods for each cylinder connecting each piston to the wobble spider. The improvement comprising: a first sleeve bearing means supporting the drive shaft in the engine block in a cantilevered manner for radial loads; a second sleeve bearing means rotatably supporting the wobble spider on the offset portion of the drive shaft for radial loads; a first roller bearing means positioned between the offset portion of the drive shaft and the wobble spider carrying thrust loadings only; a second roller bearing means carrying thrust loads only reacting to the first roller bearing located on the opposite end of the driveshaft between the shaft and the engine block.

  17. Regimes of flow induced vibration for tandem, tethered cylinders

    NASA Astrophysics Data System (ADS)

    Nave, Gary; Stremler, Mark

    2015-11-01

    In the wake of a bluff body, there are a number of dynamic response regimes that exist for a trailing bluff body depending on spacing, structural restoring forces, and the mass-damping parameter m* ζ . For tandem cylinders with low values of m* ζ , two such regimes of motion are Gap Flow Switching and Wake Induced Vibration. In this study, we consider the dynamics of a single degree-of-freedom rigid cylinder in the wake of another in these regimes for a variety of center-to-center cylinder spacings (3-5 diameters) and Reynolds numbers (4,000-11,000). The system consists of a trailing cylinder constrained to a circular arc around a fixed leading cylinder, which, for small angle displacements, bears a close resemblance to the transversely oscillating cylinders found more commonly in existing literature. From experiments on this system, we compare and contrast the dynamic response within these two regimes. Our results show sustained oscillations in the absence of a structural restoring force in all cases, providing experimental support for the wake stiffness assumption, which is based on the mean lift toward the center line of flow.

  18. Turbulent Flow Past Spinning Cylinders

    NASA Astrophysics Data System (ADS)

    Mehmedagic, Igbal; Carlucci, Donald; Carlucci, Pasquale; Thangam, Siva

    2009-11-01

    Flow past cylinders aligned along their axis where a base freely spins while attached to a non-spinning forebody is considered from a computational and experimental point of view. The time-averaged equations of motion and energy are solved using the modeled form of transport equations for the turbulence kinetic energy and the scalar form of turbulence dissipation with an efficient finite-volume algorithm. An anisotropic two-equation Reynolds-stress model that incorporates the effect of rotation-modified energy spectrum and swirl is used to perform computations for the flow past axially rotating cylinders. Both rigid cylinders as well as that of cylinders with free-spinning base are considered from a computational point of view. A subsonic wind tunnel with a forward-sting mounted spinning cylinder is used for experiments. Experiments are performed for a range of spin rates and free stream flow conditions. The experimental results of Carlucci & Thangam (2001) are used to benchmark flow over spinning cylinders. The data is extended to munitions spinning in the wake of other munitions. Applications involving the design of projectiles are discussed.

  19. Electricity's Future: The Shift to Efficiency and Small-Scale Power. Worldwatch Paper 61.

    ERIC Educational Resources Information Center

    Flavin, Christopher

    Electricity, which has largely supplanted oil as the most controversial energy issue of the 1980s, is at the center of some of the world's bitterest economic and environmental controversies. Soaring costs, high interest rates, and environmental damage caused by large power plants have wreaked havoc on the once booming electricity industry.…

  20. Reciprocity between the effects of resonant scattering and enhanced radiated power by electrically small antennas in the presence of nested metamaterial shells.

    PubMed

    Ziolkowski, Richard W; Kipple, Allison D

    2005-09-01

    Reciprocity between the power scattered by nested metamaterial shells and the power radiated by an antenna centered within those nested shells has been investigated. Resonant scattering caused by an incident, fundamental transverse-magnetic mode was found to be reciprocal to the power resonantly radiated by an electrically small electric dipole for a variety of configurations. These findings indicate that the power radiated by an electrically small antenna and scattered by an electrically small object can be significantly increased through the use of realizable metamaterials.

  1. Vortex distribution and mixed convection of liquid flow across micro-cylinders in a rectangular channel

    NASA Astrophysics Data System (ADS)

    Guan, Ning; Luan, Tao; Liu, Zhi-Gang; Zhang, Cheng-Wu; Jiang, Guilin

    2016-03-01

    The impacts of heat flux ( q = 10, 15, 20 W/cm2), cylinder diameter ( D = 300, 600, 3000 μm), aspect ratio AR ( H/D = 1, 2, 4) and block ratio BR ( W/D = 2, 4, 16) on vortex distribution and mixed convection of liquid flow across single micro-cylinder and micro-cylinder-groups (3 × 3 cylinders) were numerically investigated. The separation angles, recirculation lengths ( Lv) and Nusselt numbers were calculated with Reynolds number ranging from 10 to 60. For the single micro-cylinder, the separation angle and the value of Lv/D both became large with the increase of heat flux, and the profiles of Lv/D versus z/H were asymmetrical, which is different from the cylinders with dimensions of millimeter-level. The discrepancies of Lv/D on the same plane of micro-cylinders with different AR in the region near end-walls were larger than those near the symmetry wall. For the 3 × 3 micro-cylinder-groups, the value of Lv/D was related to the location along the axial direction, while the separation angle became small along the flowing direction. The mixed heat transfer in rectangular channel with micro-cylinders could be enhanced by changing the dimensions of the cylinders and the channel.

  2. First analytic correction to the proximity force approximation in the Casimir effect between two parallel cylinders

    NASA Astrophysics Data System (ADS)

    Teo, L. P.

    2011-09-01

    We consider the small separation asymptotic expansions of the Casimir interaction energy and the Casimir interaction force between two parallel cylinders. The leading order terms and the next-to-leading order terms are computed analytically. Four combinations of boundary conditions are considered, which are Dirichlet-Dirichlet, Neumann-Neumann, Dirichlet-Neumann, and Neumann-Dirichlet. For the case where one cylinder is inside another cylinder, the computations are shown in detail. In this case, we restrict our attention to the situation where the cylinders are strictly eccentric and the distance between the cylinders d is much smaller than the distance between the centers of the cylinders. The computations for the case where the two cylinders are exterior to each other can be done in the same way and we only present the results, which turn up to be similar to the results for the case where one cylinder is inside another except for some changes of signs. In all the scenarios we consider, the leading order terms are of order d-7/2 and they agree completely with the proximity force approximations. The results for the next-to-leading order terms are new. In the limiting case where the radius of the larger cylinder approaches infinity, the well-known results for the cylinder-plate configuration with Dirichlet-Dirichlet or Neumann-Neumann boundary conditions are recovered.

  3. Effect of a horizontal plane boundary on a falling horizontal cylinder at low Reynolds number

    NASA Astrophysics Data System (ADS)

    Chen, Y.-J.; Hussey, R. G.

    1980-05-01

    Experimental results are presented for the change in velocity of a slender cylinder with its axis horizontal as it falls through a viscous fluid toward a horizontal plane boundary. When the boundary influence is strong, the deceleration of the cylinder is observed to be constant, and the velocity extrapolates to zero at the boundary. When the relative change in velocity is small (less than 20%), it is observed to depend inversely on the square of the distance from the boundary. The Reynolds number based on cylinder diameter ranges from 2.9 to 0.015 and the Reynolds number based on cylinder length ranges from 122 to 0.16.

  4. Efficient manipulation of graphene absorption by a simple dielectric cylinder.

    PubMed

    Xiao, Ting-Hui; Gan, Lin; Li, Zhi-Yuan

    2015-07-27

    We theoretically study the absorption property of graphene manipulated by a dielectric cylinder through an analytical method. The distinctive absorption properties of incident waves with different polarizations (TM and TE) are analyzed and they are strongly correlated with the structure resonance and material dispersion. Besides, the characteristics of graphene absorption tuned by the cylinder radius and refractive index as well as the chemical potential of graphene are systematically investigated. It is found that enhancement and continuous tunability of graphene absorption can be achieved by utilizing the whispering gallery mode produced in the dielectric cylinder and harnessing the graphene optical conductivity via tuning its chemical potential by exterior electrical grating. The theoretical studies open up a simple while efficient means to manipulate the absorption of graphene in a broad frequency range via the geometric and physical configuration of hybrid graphene-microstructures.

  5. Adaptronic tools for superfinishing of cylinder bores

    NASA Astrophysics Data System (ADS)

    Roscher, Hans-Jürgen; Hochmuth, Carsten; Hoffmann, Michael; Praedicow, Michael

    2012-04-01

    Today in the production of internal combustion engines it is possible to make pistons as well as cylinders, for all practical purposes, perfectly round. The negative consequences of the subsequent assembly processes and operation of the engine is that the cylinders and pistons are deformed, resulting in a loss of power and an increase in fuel consumption. This problem can be solved by using an adaptronic tool, which can machine the cylinder to a predetermined nonround geometry, which will deform to the required geometry during assembly and operation of the engine. The article describes the actuatory effect of the tool in conjunction with its measuring and controlling algorithms. The adaptronic tool consists out the basic tool body and three axially-staggered floating cutter groups, these cutter groups consist out of guides, actuators and honing stones. The selective expansion of the tool is realised by 3 piezoelectric multilayer-actuators deployed in a series - parallel arrangement. It is also possible to superimpose actuator expansion on the conventional expansion. A process matrix is created during the processing of the required and actual contour data in a technology module. This is then transferred over an interface to the machine controller where it is finally processed and the setting values for the piezoelectric actuators are derived, after which an amplifier generates the appropriate actuator voltages. A slip ring system on the driveshaft is used to transfer the electricity to the actuators in the machining head. The functioning of the adaptronic form-honing tool and process were demonstrated with numerous experiments. The tool provides the required degrees of freedom to generate a contour that correspond to the inverse compound contour of assembled and operational engines.

  6. Optical emission from a small scale model electric arc furnace in 250-600 nm region.

    PubMed

    Mäkinen, A; Niskanen, J; Tikkala, H; Aksela, H

    2013-04-01

    Optical emission spectroscopy has been for long proposed for monitoring and studying industrial steel making processes. Whereas the radiative decay of thermal excitations is always taking place in high temperatures needed in steel production, one of the most promising environment for such studies are electric arc furnaces, creating plasma in excited electronic states that relax with intense characteristic emission in the optical regime. Unfortunately, large industrial scale electric arc furnaces also present a challenging environment for optical emission studies and application of the method is not straightforward. To study the usability of optical emission spectroscopy in real electric arc furnaces, we have developed a laboratory scale DC electric arc furnace presented in this paper. With the setup, optical emission spectra of Fe, Cr, Cr2O3, Ni, SiO2, Al2O3, CaO, and MgO were recorded in the wavelength range 250-600 nm and the results were analyzed with the help of reference data. The work demonstrates that using characteristic optical emission, obtaining in situ chemical information from oscillating plasma of electric arc furnaces is indeed possible. In spite of complications, the method could possibly be applied to industrial scale steel making process in order to improve its efficiency.

  7. Optical emission from a small scale model electric arc furnace in 250-600 nm region

    NASA Astrophysics Data System (ADS)

    Mäkinen, A.; Niskanen, J.; Tikkala, H.; Aksela, H.

    2013-04-01

    Optical emission spectroscopy has been for long proposed for monitoring and studying industrial steel making processes. Whereas the radiative decay of thermal excitations is always taking place in high temperatures needed in steel production, one of the most promising environment for such studies are electric arc furnaces, creating plasma in excited electronic states that relax with intense characteristic emission in the optical regime. Unfortunately, large industrial scale electric arc furnaces also present a challenging environment for optical emission studies and application of the method is not straightforward. To study the usability of optical emission spectroscopy in real electric arc furnaces, we have developed a laboratory scale DC electric arc furnace presented in this paper. With the setup, optical emission spectra of Fe, Cr, Cr2O3, Ni, SiO2, Al2O3, CaO, and MgO were recorded in the wavelength range 250-600 nm and the results were analyzed with the help of reference data. The work demonstrates that using characteristic optical emission, obtaining in situ chemical information from oscillating plasma of electric arc furnaces is indeed possible. In spite of complications, the method could possibly be applied to industrial scale steel making process in order to improve its efficiency.

  8. Optical emission from a small scale model electric arc furnace in 250-600 nm region

    SciTech Connect

    Maekinen, A.; Tikkala, H.; Aksela, H.; Niskanen, J.

    2013-04-15

    Optical emission spectroscopy has been for long proposed for monitoring and studying industrial steel making processes. Whereas the radiative decay of thermal excitations is always taking place in high temperatures needed in steel production, one of the most promising environment for such studies are electric arc furnaces, creating plasma in excited electronic states that relax with intense characteristic emission in the optical regime. Unfortunately, large industrial scale electric arc furnaces also present a challenging environment for optical emission studies and application of the method is not straightforward. To study the usability of optical emission spectroscopy in real electric arc furnaces, we have developed a laboratory scale DC electric arc furnace presented in this paper. With the setup, optical emission spectra of Fe, Cr, Cr{sub 2}O{sub 3}, Ni, SiO{sub 2}, Al{sub 2}O{sub 3}, CaO, and MgO were recorded in the wavelength range 250-600 nm and the results were analyzed with the help of reference data. The work demonstrates that using characteristic optical emission, obtaining in situ chemical information from oscillating plasma of electric arc furnaces is indeed possible. In spite of complications, the method could possibly be applied to industrial scale steel making process in order to improve its efficiency.

  9. Inert gas electric heater for elevated temperature testing of small propulsion components

    SciTech Connect

    Whitehead, J.C.; Lanning, R.K.; Evans, M.C.; Barabas, N.J.

    1992-06-25

    An electric heater for inert gas has been developed to enable safe, nontoxic, indoor, low cost testing of miniature propulsion components which operate on warm gas. High pressure helium regulated to 7 MPa (1000 psi) is passed through in 8-kW electric heating element to raise its temperature to 700{degree}C (1300 {degree}F) at mass flow rates up to 2 grams/sec. The pressure and temperature are independently adjustable to lower values, and the temperature controller rapidly varies the electric power in response to changes in flow rate, so that pulsed-flow as well as be tested. The heating element is a 3.2 mm (1/8 inch) diameter nickel alloy tube, which carries the helium internally and up to 80 amperes of electric current in its wall. A transparent polycarbonate safety shield ensures personnel safety while permitting direct visual and auditory observations. Digital displays of time, pressure, and temperatures are adjacent to the test hardware, to facillitate realtime interpretation of test results and video documentation. Equations for pressure drop, heat transfer, electrical resistance, stress, and thermal response time are presented to facillitate designing similar systems.

  10. Filament winding cylinders. I - Process model

    NASA Technical Reports Server (NTRS)

    Lee, Soo-Yong; Springer, George S.

    1990-01-01

    A model was developed which describes the filament winding process of composite cylinders. The model relates the significant process variables such as winding speed, fiber tension, and applied temperature to the thermal, chemical and mechanical behavior of the composite cylinder and the mandrel. Based on the model, a user friendly code was written which can be used to calculate (1) the temperature in the cylinder and the mandrel, (2) the degree of cure and viscosity in the cylinder, (3) the fiber tensions and fiber positions, (4) the stresses and strains in the cylinder and in the mandrel, and (5) the void diameters in the cylinder.

  11. Design guide for single circular cylinder in turbulent crossflow. [LMFBR

    SciTech Connect

    Mulcahy, T.M.

    1982-03-01

    A design procedure is proposed for predicting the dynamic structural response of a circular cylinder in turbulent crossflow. The procedure is based on recently obtained data for a stationary, rigid cylinder and on existing information. The procedure is not applicable to conditions where the wake vortex shedding frequency locks into a structural natural frequency. This report is self-contained in that all the information and structural analysis methods employed in the procedure are reviewed and developed. Also, an example is given to illustrate the use of the method for a typical reactor component. The calculated responses are found to be very small.

  12. Torque on a sphere inside a rotating cylinder.

    NASA Technical Reports Server (NTRS)

    Mena, B.; Levinson, E.; Caswell, B.

    1972-01-01

    A circular cylinder of finite dimensions is made to rotate around a sphere fixed in the center of the cylinder. The couple on the sphere is measured over a wide range of rotational speeds for both Newtonian and non-Newtonian fluids. For the Newtonian liquids a comparison of the experimental results is made with Collins' (1955) expansion of the couple as a series in even powers of the angular Reynolds number. For non-Newtonian liquids the apparatus proves to be extremely useful for an accurate determination of the zero shear rate viscosity using only a small amount of fluid.

  13. Direct current electrical potential measurement of the growth of small cracks

    NASA Technical Reports Server (NTRS)

    Gangloff, Richard P.; Slavik, Donald C.; Piascik, Robert S.; Van Stone, Robert H.

    1992-01-01

    The analytical and experimental aspects of the direct-current electrical potential difference (dcEPD) method for continuous monitoring of the growth kinetics of short (50 to 500 microns) fatigue cracks are reviewed, and successful applications of the deEPD method to study fatigue crack propagation in a variety of metallic alloys exposed to various environments are described. Particular attention is given to the principle of the dcEPD method, the analytical electrical potential calibration relationships, and the experimental procedures and equipment.

  14. Scattering of a Gaussian beam by a large perfectly conducting cylinder with application to optical sensors

    NASA Astrophysics Data System (ADS)

    Gardner, Judd Steven

    1999-10-01

    Optical proximity sensing is often used in industry and the commercial realm to provide a system with information it may use in some decision making process. The applications for optical proximity sensing have changed and expanded over the years, and has presented a continually increased demand for higher accuracy. In order to satisfy this demand, new optical techniques have been established which have provided more precise proximity data than ever before, e.g. Atomic Force Microscopy and Photothermal Detection. To accommodate the increase in sensing precision, the precision of the mathematical models used to predict the behavior of the optical scheme must also increase. The particular interest pursued in this dissertation involves the detection of the change in the position of a beam due to some phenomena, e.g. Photothermal Deflection or Atomic Force Microscopy. The deflection of the beam in these cases may be on the order of microradians, and too small to detect with ordinary means. To remedy this, a reflecting cylinder is strategically positioned to reflect the incident deflected beam and, by the cylinder geometry, the reflected beam from the cylinder shows an increased deflection angle compared to the incident beam. If the optical scheme has been designed successfully, the resulting deflection of the reflected beam will be large enough to be detected by a sensor. In order to predict the optical behavior of an incident deflected beam reflected from a cylinder, three mathematical methods, Geometrical Optics, Physical Optics, and an Exact Formulation rigorously based on Maxwell's equations are employed. From these methods, a Geometrical Optics solution, two Physical Optics solutions, and an Exact solution are obtained and compared to demonstrate the accuracy of these mathematical models to predict the electric field behavior of a beam reflected from a cylinder. In all cases a Gaussian, well focused beam is used. The near, transitional, and far zones are considered

  15. Effect of blade flutter and electrical loading on small wind turbine noise

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The effect of blade flutter and electrical loading on the noise level of two different size wind turbines was investigated at the Conservation and Production Research Laboratory (CPRL) near Bushland, TX. Noise and performance data were collected on two blade designs tested on a wind turbine rated a...

  16. Homemade Electricity: An Introduction to Small-Scale Wind, Hydro, and Photovoltaic Systems.

    ERIC Educational Resources Information Center

    Smith, Diane

    This report consists of three parts. The first part provides advice (in the form of questions and answers) to prospective individual power producers who are considering investing in electricity-producing systems and in generating their own power. A list of Public Utilities Regulatory Policies Act (PURPA) regulations is included. This legislation…

  17. Corrosion of breached UF{sub 6} storage cylinders

    SciTech Connect

    Barber, E.J.; Taylor, M.S.; DeVan, J.H.

    1993-02-01

    This paper describes the corrosion processes that occurred following the mechanical failure of two steel 14-ton storage cylinders containing depleted UF{sub 6}. The failures both were traced to small mechanical tears that occurred during stacking of the cylinders. Although subsequent corrosion processes greatly extended the openings in the wall. the reaction products formed were quite protective and prevented any significant environmental insult or loss of uranium. The relative sizes of the two holes correlated with the relative exposure times that had elapsed from the time of stacking. From the sizes and geometries of the two holes, together with analyses of the reaction products, it was possible to determine the chemical reactions that controlled the corrosion process and to develop a scenario for predicting the rate of hydrolysis of UF{sub 6}, the loss rate of HF, and chemical attack of a breached UF{sub 6} storage cylinder.

  18. Corrosion of breached UF[sub 6] storage cylinders

    SciTech Connect

    Barber, E.J.; Taylor, M.S.; DeVan, J.H.

    1993-01-01

    This paper describes the corrosion processes that occurred following the mechanical failure of two steel 14-ton storage cylinders containing depleted UF[sub 6]. The failures both were traced to small mechanical tears that occurred during stacking of the cylinders. Although subsequent corrosion processes greatly extended the openings in the wall. the reaction products formed were quite protective and prevented any significant environmental insult or loss of uranium. The relative sizes of the two holes correlated with the relative exposure times that had elapsed from the time of stacking. From the sizes and geometries of the two holes, together with analyses of the reaction products, it was possible to determine the chemical reactions that controlled the corrosion process and to develop a scenario for predicting the rate of hydrolysis of UF[sub 6], the loss rate of HF, and chemical attack of a breached UF[sub 6] storage cylinder.

  19. A Zoology of unstable modes in a stratified cylinder wake

    NASA Astrophysics Data System (ADS)

    Bosco, Mickael; Meunier, Patrice

    2013-11-01

    Although the dynamics of a cylinder wake is well known and extremely rich for a homogeneous fluid, very few studies have been focused on stratified wakes despite the obvious extensive number of applications for geophysical flows and submarine wakes. The presence of the stratification may largely modify the dynamics of the wake. The study is devoted to understand the effect of the tilt and also of a strong stratification. So extensive experimental and numerical results have been investigated to describe the full dynamics of a tilted cylinder wake. For weak stratification and small tilt angle, the classical mode A found for a homogeneous fluid is still present, but for a large tilt angle, an instability appearing far from the cylinder is created. The case of a cylinder towed a very stratified fluid has been finally investigated. The dynamics is strongly modified and for moderate tilt angles, a new unstable mode appears with a structure similar to the Kelvin-Helmholtz billows (observed in the critical layer of a tilted stratified vortex), whereas for large tilt angles, another unstable mode characterized by a strong shear appears generated without a 2D von Karman structure. This reveals the rich dynamics of the cylinder wake in the presence of a stable stratification.

  20. The history of re-connection and the concept of the solar wind plasma with relatively small electrical conductivity

    NASA Technical Reports Server (NTRS)

    Chertkov, A. D.

    1995-01-01

    Petschek's 're-connection' model, aspiring to be universal, treated as a boundary problem meets unresolvable difficulties connected with impossibility to specify correctly boundary and initial conditions. This problem was incorrectly formulated. Hence, ineradicable logarithmic singularities occurred on the boundary surfaces. Attempts to eliminate them by incorporating the finite electrical conductivity are incorrect. This should lead to the change in the equation type, boundary condition type and in consequence to the change in solutions. Besides, the slow mode shocks cannot be driven by small internal source. As an alternative a new plasma concept is suggested. The state of fully ionized plasma in space depends completely on the entropy of the plasma heating source and on the process in which plasma is involved. The presumptive source of the solar wind creation - the induction electric field of the solar origin - has very low entropy. The state of plasma should be very far from the thermodynamic equilibrium. Debye's screening is not complete. The excitation of the powerful resonant self-consistent electric fields in plasma provides low electric conductivity. The MHD problems should be treated in frameworks of dissipative theories.

  1. Rotating Cylinder Treatment System Demonstration

    EPA Science Inventory

    In August 2008, a rotating cylinder treatment system (RCTSTM) demonstration was conducted near Gladstone, CO. The RCTSTM is a novel technology developed to replace the aeration/oxidation and mixing components of a conventional lime precipitation treatment s...

  2. Video Analysis of Rolling Cylinders

    ERIC Educational Resources Information Center

    Phommarach, S.; Wattanakasiwich, P.; Johnston, I.

    2012-01-01

    In this work, we studied the rolling motion of solid and hollow cylinders down an inclined plane at different angles. The motions were captured on video at 300 frames s[superscript -1], and the videos were analyzed frame by frame using video analysis software. Data from the real motion were compared with the theory of rolling down an inclined…

  3. Dragging a floating horizontal cylinder

    NASA Astrophysics Data System (ADS)

    Lee, Duck-Gyu; Kim, Ho-Young

    2010-11-01

    A cylinder immersed in a fluid stream experiences a drag, and it is well known that the drag coefficient is a function of the Reynolds number only. Here we study the force exerted on a long horizontal cylinder that is dragged perpendicular to its axis while floating on an air-water interface with a high Reynolds number. In addition to the flow-induced drag, the floating body is subjected to capillary forces along the contact line where the three phases of liquid/solid/gas meet. We first theoretically predict the meniscus profile around the horizontally moving cylinder assuming the potential flow, and show that the profile is in good agreement with that obtained experimentally. Then we compare our theoretical predictions and experimental measurement results for the drag coefficient of a floating horizontal cylinder that is given by a function of the Weber number and the Bond number. This study can help us to understand the horizontal motion of partially submerged objects at air-liquid interface, such as semi-aquatic insects and marine plants.

  4. Plasmonic corrugated cylinder-cone terahertz probe.

    PubMed

    Yao, Haizi; Zhong, Shuncong

    2014-08-01

    The spoof surface plasmon polariton (SPP) effect on the electromagnetic field distribution near the tip of a periodically corrugated metal cylinder-cone probe working at the terahertz regime was studied. We found that radially polarized terahertz radiation could be coupled effectively through a spoof SPP into a surface wave and propagated along the corrugated surface, resulting in more than 20× electric field enhancement near the tip of probe. Multiple resonances caused by the antenna effect were discussed in detail by finite element computation and theoretical analysis of dispersion relation for spoof SPP modes. Moreover, the key figures of merit such as the resonance frequency of the SPP can be flexibly tuned by modifying the geometry of the probe structure, making it attractive for application in an apertureless background-free terahertz near-field microscope. PMID:25121543

  5. Analysis on autofrettage of cylinders

    NASA Astrophysics Data System (ADS)

    Zhu, Ruilin; Zhu, Guolin; Tang, Feng

    2012-05-01

    Autofrettage is an effective technique to improve load-bearing capacity and safety for pressure vessels. For autofrettaged cylinder, the depth of plastic zone, or overstrain is a key factor which affects load-bearing capacity and safety. The previous research on overstrain was not done in terms of the point of view of raising load-bearing capacity as far as possible and simultaneously avoiding compressive yield for cylinders experiencing autofrettage handling, and there were no analytic solutions of autofrettage in the above view point presented, the 3rd and 4th strength theories were not applied synthetically in the research to compare the results from these two theories. In this paper, with the aid of the analytic method, based on summing up the authors' previous research, results from autofrettage of a cylinder based on the 3rd and 4th strength theories are studied and compared, and the laws contained in the results are looked into. Then, the essential cause and reason for the obtained laws are analyzed and the inherent and meaning relations between various parameters in autofrettage theory are revealed. It is shown that the maximum radius ratio for equivalent residual stress at inside surface never exceeds the yield strength even for a cylinder experiencing wholly yielded autofrettage, or the critical radius ratio is k c=2.218 457 489 916 7…, irrespective of the 3rd or 4th strength theories. The equation relating the depth of plastic zone with the thickness of a cylinder is identical for the 3rd and 4th strength theories. In form, the optimum load-bearing capacity of an autofrettaged cylinder is two times the initial yield pressure of the unautofrettaged cylinder irrespective of the 3rd or 4th strength theory. The revealed inherent relations between various parameters and varying laws of the parameters as well as the forms of the relations under the 3rd and 4th strength theories not only have theoretical meanings but also have prospects in engineering

  6. Thin film deposition by electric and magnetic crossed-field diode sputtering. [Patent application

    DOEpatents

    Welch, K.M.

    1975-04-04

    Applying a coating of titanium nitride to a klystron window by means of a cross-field diode sputtering array is described. The array is comprised of a cohesive group of numerous small hollow electrically conducting cylinders and is mounted so that the open ends of the cylinders on one side of the group are adjacent to a titanium cathode plate. The workpiece is mounted so as to face the open ends of the other side of the group. A magnetic field is applied to the array so as to be coaxial with the cylinders and a potential is applied across the cylinders and the cathode plate, the cylinders as an anode being positive with respect to the cathode plate. The cylinders, the cathode plate, and the workpiece are situated in an atmosphere of nitrogen which becomes ionized such as by field emission because of the electric field between the cylinders and cathode plate, thereby establishing an anode-cathode discharge that results in sputtering of the titanium plate. The sputtered titanium coats the workpiece and chemically combines with the nitrogen to form a titanium nitride coating on the workpiece. Gas pressure, gas mixtures, cathode material composition, voltages applied to the cathode and anode, the magnetic field, cathode, anode and workpiece spacing, and the aspect ratio (ratio of length to inner diameter) of the anode cylinders, all may be controlled to provide consistent optimum thin film coatings of various compositions and thickness. Another facet of the disclosure is the coating of microwave components per se with titanium nitride to reduce multifactoring under operating conditions of the components.

  7. Thin film deposition by electric and magnetic crossed-field diode sputtering

    DOEpatents

    Welch, Kimo M.

    1977-01-01

    Applying a thin film coating to the surface of a workpiece, in particular, applying a coating of titanium nitride to a klystron window by means of a crossed-field diode sputtering array. The array is comprised of a cohesive group of numerous small hollow electrically conducting cylinders and is mounted so that the open ends of the cylinders on one side of the group are adjacent a titanium cathode plate. The workpiece is mounted so as to face the open ends of the other side of the group. A magnetic field is applied to the array so as to be coaxial with the cylinders and a potential is applied across the cylinders and the cathode plate, the cylinders as an anode being positive with respect to the cathode plate. The cylinders, the cathode plate and the workpiece are situated in an atmosphere of nitrogen which becomes ionized such as by field emission because of the electric field between the cylinders and cathode plate, thereby establishing an anode-cathode discharge that results in sputtering of the titanium plate. The sputtered titanium coats the workpiece and chemically combines with the nitrogen to form a titanium nitride coating on the workpiece. Gas pressure, gas mixtures, cathode material composition, voltages applied to the cathode and anode, the magnetic field, cathode, anode and workpiece spacing, and the aspect ratio (ratio of length to inner diameter) of the anode cylinders, all may be controlled to provide consistent optimum thin film coatings of various compositions and thicknesses. Another facet of the disclosure is the coating of microwave components per se with titanium nitride to reduce multipactoring under operating conditions of the components.

  8. Thin film deposition by electric and magnetic crossed-field diode sputtering

    DOEpatents

    Welch, Kimo M.

    1980-01-01

    Applying a thin film coating to the surface of a workpiece, in particular, applying a coating of titanium nitride to a klystron window by means of a crossed-field diode sputtering array. The array is comprised of a cohesive group of numerous small hollow electrically conducting cylinders and is mounted so that the open ends of the cylinders on one side of the group are adjacent a titanium cathode plate. The workpiece is mounted so as to face the open ends of the other side of the group. A magnetic field is applied to the array so as to be coaxial with the cylinders and a potential is applied across the cylinders and the cathode plate, the cylinders as an anode being positive with respect to the cathode plate. The cylinders, the cathode plate and the workpiece are situated in an atmosphere of nitrogen which becomes ionized such as by field emission because of the electric field between the cylinders and cathode plate, thereby establishing an anode-cathode discharge that results in sputtering of the titanium plate. The sputtered titanium coats the workpiece and chemically combines with the nitrogen to form a titanium nitride coating on the workpiece. Gas pressure, gas mixtures, cathode material composition, voltages applied to the cathode and anode, the magnetic field, cathode, anode and workpiece spacing, and the aspect ratio (ratio of length to inner diameter) of the anode cylinders, all may be controlled to provide consistent optimum thin film coatings of various compositions and thicknesses. Another facet of the disclosure is the coating of microwave components per se with titanium nitride to reduce multipactoring under operating conditions of the components.

  9. Electric quadrupole polarizabilities of nuclear magnetic shielding in some small molecules.

    PubMed

    Ferraro, M B; Caputo, M C; Pagola, G I; Lazzeretti, P

    2008-01-28

    Computational procedures, based on (i) the Ramsey common origin approach and (ii) the continuous transformation of the origin of the quantum mechanical current density-diamagnetic zero (CTOCD-DZ), were applied at the Hartree-Fock level to determine electric quadrupole polarizabilities of nuclear magnetic shielding for molecules in the presence of a nonuniform electric field with a uniform gradient. The quadrupole polarizabilities depend on the origin of the coordinate system, but values of the magnetic field induced at a reference nucleus, determined via the CTOCD-DZ approach, are origin independent for any calculations relying on the algebraic approximation, irrespective of size and quality of the (gaugeless) basis set employed. On the other hand, theoretical estimates of the induced magnetic field obtained by single-origin methods are translationally invariant only in the limit of complete basis sets. Calculations of electric quadrupole polarizabilities of nuclear magnetic shielding are reported for H(2), HF, H(2)O, NH(3), and CH(4) molecules.

  10. Wake-induced vibrations in Tandem Cylinders

    NASA Astrophysics Data System (ADS)

    Mysa, Ravi Chaithanya; Jaiman, Rajeev Kumar

    2015-11-01

    The upstream cylinder is fixed in the tandem cylinders arrangement. The downstream cylinder is placed at a distance of four diameters from the upstream cylinder in the free stream direction and is mounted on a spring. The dynamic response of the downstream cylinder is studied at Reynolds number of 10,000. The transverse displacement amplitude of the downstream cylinder is larger compared to that of single cylinder in the post-lock-in region. The transverse dynamic response of the downstream cylinder in the post-lock-in region is characterized by a dominant low frequency component compared to shed frequency, which is nearer to the structural natural frequency. The interaction of upstream wake with the downstream cylinder is carefully analyzed to understand the introduction of low frequency component in the transverse load along with the shed frequency. We found that the stagnation point moves in proportional to the velocity of the cylinder and is in-phase with the velocity. The low frequency component in the stagnation point movement on the downstream cylinder is sustained by the interaction of upstream wake. The frequencies in the movement of the stagnation point is reflected in the transverse load resulting in large deformation of the cylinder. The authors wish to acknowledge support from A*STAR- SERC and Singapore Maritime Institute.

  11. 49 CFR 230.83 - Cylinder cocks.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ..., DEPARTMENT OF TRANSPORTATION STEAM LOCOMOTIVE INSPECTION AND MAINTENANCE STANDARDS Steam Locomotives and Tenders Cabs, Warning Signals, Sanders and Lights § 230.83 Cylinder cocks. Each steam locomotive shall be equipped with cylinder cocks which can be operated from the cab of the steam locomotive. All cylinder...

  12. 49 CFR 230.83 - Cylinder cocks.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ..., DEPARTMENT OF TRANSPORTATION STEAM LOCOMOTIVE INSPECTION AND MAINTENANCE STANDARDS Steam Locomotives and Tenders Cabs, Warning Signals, Sanders and Lights § 230.83 Cylinder cocks. Each steam locomotive shall be equipped with cylinder cocks which can be operated from the cab of the steam locomotive. All cylinder...

  13. 49 CFR 230.83 - Cylinder cocks.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ..., DEPARTMENT OF TRANSPORTATION STEAM LOCOMOTIVE INSPECTION AND MAINTENANCE STANDARDS Steam Locomotives and Tenders Cabs, Warning Signals, Sanders and Lights § 230.83 Cylinder cocks. Each steam locomotive shall be equipped with cylinder cocks which can be operated from the cab of the steam locomotive. All cylinder...

  14. 49 CFR 230.83 - Cylinder cocks.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ..., DEPARTMENT OF TRANSPORTATION STEAM LOCOMOTIVE INSPECTION AND MAINTENANCE STANDARDS Steam Locomotives and Tenders Cabs, Warning Signals, Sanders and Lights § 230.83 Cylinder cocks. Each steam locomotive shall be equipped with cylinder cocks which can be operated from the cab of the steam locomotive. All cylinder...

  15. 49 CFR 230.83 - Cylinder cocks.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ..., DEPARTMENT OF TRANSPORTATION STEAM LOCOMOTIVE INSPECTION AND MAINTENANCE STANDARDS Steam Locomotives and Tenders Cabs, Warning Signals, Sanders and Lights § 230.83 Cylinder cocks. Each steam locomotive shall be equipped with cylinder cocks which can be operated from the cab of the steam locomotive. All cylinder...

  16. Externally pressurized porous cylinder for multiple surface aerosol generation and method of generation

    DOEpatents

    Apel, Charles T.; Layman, Lawrence R.; Gallimore, David L.

    1988-01-01

    A nebulizer for generating aerosol having small droplet sizes and high efficiency at low sample introduction rates. The nebulizer has a cylindrical gas permeable active surface. A sleeve is disposed around the cylinder and gas is provided from the sleeve to the interior of the cylinder formed by the active surface. In operation, a liquid is provided to the inside of the gas permeable surface. The gas contacts the wetted surface and forms small bubbles which burst to form an aerosol. Those bubbles which are large are carried by momentum to another part of the cylinder where they are renebulized. This process continues until the entire sample is nebulized into aerosol sized droplets.

  17. Adsorption in sparse networks. 1: Cylinder model

    SciTech Connect

    Scherer, G.W.

    1998-06-15

    Materials with very low density, such as aerogels, are networks with polymers or chains of particles joined at nodes, where the spacing of the nodes is large compared to the thickness of the chains. In such a material, most of the solid surface has positive curvature, so condensation of an adsorbate is more difficult than condensation in a body containing cavities whose surfaces have negative curvature. A model is presented in which the network is represented by straight cylinders joined at nodes with coordination numbers 4, 6, or 12. The shape of the adsorbate/adsorptive interface is obtained for each network by minimizing its surface area. The adsorption behavior is found to depend on the ratio of the node separation, l, to the radius of the cylinders, a: if l/a exceeds a critical value (which depends on the coordination of the node), then the curvature of the adsorbate/adsorptive interface approaches zero while the adsorbate occupies a small fraction of the pore volume; if l/a is less than the critical value, then condensation occurs. Even in the latter case, interpretation of the adsorption isotherm in terms of cylindrical pores (as in the BJH model) yields apparent pore sizes much greater than the actual spacing of the nodes. In a companion paper, this model is applied to silica aerogels and found to give a good fit to both the adsorption and desorption curves with a single distribution of node spacings.

  18. Small and medium-sized high-temperature reactors for generation of electricity, process steam and district heat

    SciTech Connect

    Schoening, J.

    1988-01-01

    The HTR reactor line of BBC/HRB has been designed to cover the requirements in the market of nuclear power energy of the time being and in the future. Cornerstones of the group's future HTR line are the HTR 500 (550 MWe) and the HTR 100 (100 MWe) for the generation of electricity and process steam, with the possibility of heat extraction for district heating. The HTR 500 design characteristics, reasons for choice of a 500 MW design, economics of the HTR 500, the HTR 100 design characteristics, process heat application, and small heating reactors are discussed in the paper.

  19. The demagnetizing energies of a uniformly magnetized cylinder with an elliptic cross-section

    NASA Astrophysics Data System (ADS)

    Goode, D. A.; Rowlands, G.

    2003-12-01

    Analytic expressions for the demagnetizing energies are obtained in the form of partial series, for long elliptic cylinders and for squat ones where the ellipticity of the cross-section is unrestrained. This leaves just a small range where the demagnetizing energies are not well defined. It is found that by replacing the elliptic cylinders with rectangular blocks, a good approximation to the demagnetizing energy may be made in this small range.

  20. Short report: effect of two prokinetic drugs on the electrical and motor activity of the small bowel in dogs.

    PubMed

    Defilippi, C; Gomez, E

    1993-06-01

    The effects of trimebutine and domperidone, on the electrical and motor activity of the upper small bowel in dogs, were studied simultaneously by means of a suction electrode and a manometric catheter. Trimebutine, given during phases I and II of the migratory motor complex, was followed by a period of regular spike potentials and contractions; the increased motor activity was significantly greater when the drug was given during phase II. Domperidone, when injected in phase I, was followed by an irregular pattern of spike potentials and contractions of low amplitude. By contrast, activity was not augmented when the drug was given during phase II. We conclude that the effects of drugs, such as trimebutine and domperidone, on the canine small bowel are influenced by the phase of the migratory motor complex. PMID:8364138

  1. Electric propulsion systems for small satellites: the low earth orbit mission perseus

    NASA Astrophysics Data System (ADS)

    Bock, D.; Herdrich, G.; Lau, M.; Lengowski, M.; Schönherr, T.; Steinmetz, F.; Wollenhaupt, B.; Zeile, O.; Röser, H.-P.

    2011-10-01

    The Institute of Space Systems, Universität Stuttgart, launched a "Small a Satellite Program" in 2002. The first two of the four planed small satellites, Flying Laptop and PERSEUS, are both Low Earth Orbit (LEO) missions. The third mission Cermit is a reentry satellite and the last of the small satellites - Lunar Mission BW1 - is a mission to the Moon. For this purpose, different propulsion systems are mandatory. The propulsion system for Lunar Mission BW1 will consist of two different types of thruster systems: a cluster of pulsed magnetoplasmadynamic (MPD) thrusters (SIMP-LEX) using solid polytetrafluoroethylene (PTFE) as propellant and a thermal arcjet thruster (TALOS) using gaseous ammonia as propellant. Both thruster systems are currently under development at IRS. They are planned to be tested on board the small satellite mission PERSEUS, one of the precursor missions of Lunar Mission BW1. The thruster systems have been investigated intensely in the past and, furthermore, optimization of the thrusters with respect to the mission requirements of Lunar Mission BW1 has been started. The test procedures for the technology demonstration on the PERSEUS satellite are under development at present.

  2. Loss of interstitial cells of Cajal and development of electrical dysfunction in murine small bowel obstruction

    PubMed Central

    Chang, In-Youb; Glasgow, Nichola J; Takayama, Ichiro; Horiguchi, Kazuhide; Sanders, Kenton M; Ward, Sean M

    2001-01-01

    Partial obstruction of the murine ileum led to changes in the gross morphology and ultrastructure of the tunica muscularis. Populations of interstitial cells of Cajal (ICC) decreased oral, but not aboral, to the site of obstruction. Since ICC generate and propagate electrical slow waves in gastrointestinal muscles, we investigated whether the loss of ICC leads to loss of function in partial bowel obstruction. Changes in ICC networks and electrical activity were monitored in the obstructed murine intestine using immunohistochemistry, electron microscopy and intracellular electrophysiological techniques. Two weeks following the onset of a partial obstruction, the bowel increased in diameter and hypertrophy of the tunica muscularis was observed oral to the obstruction site. ICC networks were disrupted oral to the obstruction, and this disruption was accompanied by the loss of electrical slow waves and responses to enteric nerve stimulation. These defects were not observed aboral to the obstruction. Ultrastructural analysis revealed no evidence of cell death in regions where the lesion in ICC networks was developing. Cells with a morphology intermediate between smooth muscle cells and fibroblasts were found in locations that are typically populated by ICC. These cells may have been the redifferentiated remnants of ICC networks. Removal of the obstruction led to the redevelopment of ICC networks and recovery of slow wave activity within 30 days. Neural responses were partially restored in 30 days. These data describe the plasticity of ICC networks in response to partial obstruction. After obstruction the ICC phenotype was lost, but these cells regenerated when the obstruction was removed. This model may be an important tool for evaluating the cellular/molecular factors responsible for the regulation and maintenance of the ICC phenotype. PMID:11600689

  3. Lightweight Integrated Solar Array and Transceiver. [Improving Electrical Power and Communication Capabilities in Small Spacecraft

    NASA Technical Reports Server (NTRS)

    Carr, John; Martinez, Andres; Petro, Andrew

    2015-01-01

    The Lightweight Integrated Solar Array and Transceiver (LISA-T) project will leverage several existing and on-going efforts at Marshall Space Flight Center (MSFC) for the design, development, fabrication, and test of a launch stowed, orbit deployed structure on which thin-film photovoltaics for power generation and antenna elements for communication, are embedded. Photovoltaics is a method for converting solar energy into electricity using semiconductor materials. The system will provide higher power generation with a lower mass, smaller stowage volume, and lower cost than the state of the art solar arrays, while simultaneously enabling deployable antenna concepts.

  4. The Effect of Baffles on the Temperature Distribution and Heat-transfer Coefficients of Finned Cylinders

    NASA Technical Reports Server (NTRS)

    Schey, Oscar W; Rollin, Vern G

    1936-01-01

    This report presents the results of an investigation to determine the effect of baffles on the temperature distribution and the heat-transfer coefficient of finned cylinders. The tests were conducted in a 30-inch wind tunnel on electrically heated cylinders with fins of 0.25 and 0.31 inch pitch. The results of these tests showed that the use of integral baffles gave a reduction of 31.9 percent in the rear wall temperatures and an increase of 54.2 percent in the heat transfer coefficient as compared with a cylinder without baffles.

  5. Self-Excited Fluidic Energy Harvesters with Finite-Length Cylinders

    NASA Astrophysics Data System (ADS)

    Akaydin, Huseyin; Duquesnois, Chloe; Elvin, Niell; Andreopoulos, Yiannis

    2011-11-01

    In this experimental work, we explore the possibility of using piezoelectric materials for harvesting electrical energy from fluid flow. Such harvesters may be used for powering small sensors and obviate the need for batteries and/or power lines. Piezoelectric harvesters behave as AC-coupled devices and need oscillatory motion to generate an electrical output. The harvester should be designed to be ``self-excited,'' i.e. capable of initiating and sustaining the necessary oscillations in steady and uniform flows. The present configuration consists of a piezoelectric cantilever beam with a cylindrical tip body which promotes aeroelastic vibrations induced by vortex shedding. The harvester was tested in a wind tunnel and it produced 0.1 mW of electrical power at a flow speed of about 1.19 m/s. Using strain measurements and a distributed parameter model, the harvested electrical power was predicted, and a reasonable agreement is obtained with the measurements. The magnitude and frequency of the driving aerodynamic forces were also estimated. Results were comparable with literature data on flow past oscillating cylinders. Finally, the effect of using various shapes of tip body is presented. Sponsored by NSF Grant: CBET #1033117.

  6. Biological effects of 60-Hz electric fields on small and large laboratory animals

    SciTech Connect

    Phillips, R.D.

    1981-01-01

    Rats and mice were exposed to 60-Hz electric fields up to 330 kV/m for durations as long as four months. No significant effects were found in the following major areas: metabolic status and growth; organ and tissue morphology; brain morphology; cardiovascular function; serum chemistry; reproduction; prenatal growth and development; teratology; bone growth; peripheral nerve function; humoral and cell-mediated immunity; susceptibility to viral infection; cell and membrane function; illness/malaise; and cytogenetics. Statistically significant effects of electric field exposures were observed in the following areas: bone fracture repair; neonatal development; neuromuscular function; endocrinology; hematology; neurochemistry; urine volume and chemistry; sympathetic nervous system; behavior. It is likely that many of the effects observed are secondary to chronic stimulation of the animal by the field. Our research efforts have shifted to an in-depth investigation of nervous system functions, with emphasis in behavior, neurochemistry, neurophysiology, and dosimetry. Current and future research in these areas will focus on: relationship of effects to field strength and duration of exposure; recovery from observed effects; fundamental understanding of observed effects; fundamental understanding of interaction of field with animal (dosimetry); and biological significance of observed effects. (ERB)

  7. A molecular insight into the electro-transfer of small molecules through electropores driven by electric fields.

    PubMed

    Casciola, Maura; Tarek, Mounir

    2016-10-01

    The transport of chemical compounds across the plasma membrane into the cell is relevant for several biological and medical applications. One of the most efficient techniques to enhance this uptake is reversible electroporation. Nevertheless, the detailed molecular mechanism of transport of chemical species (dyes, drugs, genetic materials, …) following the application of electric pulses is not yet fully elucidated. In the past decade, molecular dynamics (MD) simulations have been conducted to model the effect of pulsed electric fields on membranes, describing several aspects of this phenomenon. Here, we first present a comprehensive review of the results obtained so far modeling the electroporation of lipid membranes, then we extend these findings to study the electrotransfer across lipid bilayers subject to microsecond pulsed electric fields of Tat11, a small hydrophilic charged peptide, and of siRNA. We use in particular a MD simulation protocol that allows to characterize the transport of charged species through stable pores. Unexpectedly, our results show that for an electroporated bilayer subject to transmembrane voltages in the order of 500mV, i.e. consistent with experimental conditions, both Tat11 and siRNA can translocate through nanoelectropores within tens of ns. We discuss these results in comparison to experiments in order to rationalize the mechanism of drug uptake by cells. This article is part of a Special Issue entitled: Biosimulations edited by Ilpo Vattulainen and Tomasz Róg. PMID:27018309

  8. The effect of electrical stimulation on post mortem myofibrillar protein degradation and small heat shock protein kinetics in bull beef.

    PubMed

    Contreras-Castillo, C J; Lomiwes, D; Wu, G; Frost, D; Farouk, M M

    2016-03-01

    This study aimed to determine the effect of electrical stimulation and ultimate pH (pHu) on shear force, myofibrillar protein degradation and small heat shock protein (sHSP) concentrations in M. longissimus lumborum (LL). The LL from both sides of carcasses (n=15) was excised with low voltage electrical stimulation (ES) applied to an LL muscle from one side, while the opposing LL muscle was not stimulated (NS). Muscles were categorised into low (pHu<5.8), intermediate (5.8≤pHu<6.2) and high pHu (pHu≥6.2) and aged for up to 28days post mortem at -1.5°C. High pHu meat tenderised faster which corresponded with the faster degradation of titin and desmin in this group compared with low and intermediate pHu meat. Electrical stimulation significantly affected the variable levels of αβ-crystallin and HSP20 with higher concentrations of these sHSP in ES muscles at later ageing timepoints compared with NS muscles.

  9. Scattering from cylinders using the two-dimensional vector plane wave spectrum: addendum.

    PubMed

    Pawliuk, Peter; Yedlin, Matthew

    2012-03-01

    The solution for the vector plane wave spectrum scattering from multiple cylinders by Pawliuk and Yedlin [J. Opt. Soc. A28, 1177 (2011)] only provided the single scattering coefficients for the TM polarization case. The TE solution is similar except for the form of the single scattering coefficients. Here we describe the single scattering coefficients for both polarizations and three types of cylinders: dielectrics, perfect electric conductors, and perfect magnetic conductors.

  10. Small Scale Electrical Power Generation from Heat Co-Produced in Geothermal Fluids: Mining Operation

    SciTech Connect

    Clark, Thomas M.; Erlach, Celeste

    2014-12-30

    Demonstrate the technical and economic feasibility of small scale power generation from low temperature co-produced fluids. Phase I is to Develop, Design and Test an economically feasible low temperature ORC solution to generate power from lower temperature co-produced geothermal fluids. Phase II &III are to fabricate, test and site a fully operational demonstrator unit on a gold mine working site and operate, remotely monitor and collect data per the DOE recommended data package for one year.

  11. Conjugate natural convection between horizontal eccentric cylinders

    NASA Astrophysics Data System (ADS)

    Nasiri, Davood; Dehghan, Ali Akbar; Hadian, Mohammad Reza

    2016-06-01

    This study involved the numerical investigation of conjugate natural convection between two horizontal eccentric cylinders. Both cylinders were considered to be isothermal with only the inner cylinder having a finite wall thickness. The momentum and energy equations were discretized using finite volume method and solved by employing SIMPLER algorithm. Numerical results were presented for various solid-fluid conductivity ratios (KR) and various values of eccentricities in different thickness of inner cylinder wall and also for different angular positions of inner cylinder. From the results, it was observed that in an eccentric case, and for KR < 10, an increase in thickness of inner cylinder wall resulted in a decrease in the average equivalent conductivity coefficient (overline{{K_{eq} }} ); however, a KR > 10 value caused an increase in overline{{K_{eq} }} . It was also concluded that in any angular position of inner cylinder, the value of overline{{K_{eq} }} increased with increase in the eccentricity.

  12. A study of the air movement in two aircraft-engine cylinders

    NASA Technical Reports Server (NTRS)

    Lee, Dana W

    1940-01-01

    Studies were made of the air movements in the NACA glass-cylinder apparatus using cylinder heads similar to those on the Wright R-1820-G engine and the Pratt & Whitney Wasp engine as modified by the Eclipse Aviation Corporation to use fuel-injection equipment. The air movements were made visible by mixing small feathers with the air; high-speed motion pictures were than taken of the feathers as they swirled about the inside the glass cylinder. The test engine speeds were 350, 500, and 1,000 r.p.m. Motion pictures were also taken of gasoline sprays injected into the cylinder during the intake stroke. The air flow produced by each cylinder head is described and some results of the velocity measurements of feathers are presented. The apparent time intervals required for vaporization of the gasoline sprays are also given.

  13. Supernumerary spacing of rainbows produced by an elliptical-cross-section cylinder. I. Theory.

    PubMed

    Lock, J A

    2000-09-20

    A sequence of rainbows is produced in light scattering by a particle of high symmetry in the short-wavelength limit, and a supernumerary interference pattern occurs to one side of each rainbow. Using both a ray-tracing procedure and the Debye-series decomposition of first-order perturbation wave theory, I examine the spacing of the supernumerary maxima and minima as a function of the cylinder rotation angle when an elliptical-cross-section cylinder is normally illuminated by a plane wave. I find that the supernumerary spacing depends sensitively on the cylinder-cross-section shape, and the spacing varies sinusoidally as a function of the cylinder rotation angle for small cylinder ellipticity. I also find that relatively large uncertainties in the supernumerary spacing affect the rainbow angle only minimally. PMID:18350103

  14. Generalized Bistability in Origami Cylinders

    NASA Astrophysics Data System (ADS)

    Reid, Austin; Adda-Bedia, Mokhtar; Lechenault, Frederic

    Origami folded cylinders (origami bellows) have found increasingly sophisticated applications in space flight, medicine, and even experimental nuclear physics. In spite of this interest, a general understanding of the dynamics of an origami folded cylinder has been elusive. By solving the fully constrained behavior of a periodic fundamental origami cell defined by unit vectors, we have found an analytic solution for all possible rigid-face states accessible from a cylindrical Miura-ori pattern. Although an idealized bellows has two rigid-face configurations over a well-defined region, a physical device, limited by nonzero material thickness and forced to balance hinge with plate-bending energy, often cannot stably maintain a stowed configuration. We have identified and measured the parameters which control this emergent bistability, and have demonstrated the ability to fabricate bellows with tunable deployability.

  15. Stratified spin-up in a sliced, square cylinder

    SciTech Connect

    Munro, R. J.; Foster, M. R.

    2014-02-15

    We previously reported experimental and theoretical results on the linear spin-up of a linearly stratified, rotating fluid in a uniform-depth square cylinder [M. R. Foster and R. J. Munro, “The linear spin-up of a stratified, rotating fluid in a square cylinder,” J. Fluid Mech. 712, 7–40 (2012)]. Here we extend that analysis to a “sliced” square cylinder, which has a base-plane inclined at a shallow angle α. Asymptotic results are derived that show the spin-up phase is achieved by a combination of the Ekman-layer eruptions (from the perimeter region of the cylinder's lid and base) and cross-slope-propagating stratified Rossby waves. The final, steady state limit for this spin-up phase is identical to that found previously for the uniform depth cylinder, but is reached somewhat more rapidly on a time scale of order E{sup −1/2}Ω{sup −1}/log (α/E{sup 1/2}) (compared to E{sup −1/2}Ω{sup −1} for the uniform-depth cylinder), where Ω is the rotation rate and E the Ekman number. Experiments were performed for Burger numbers, S, between 0.4 and 16, and showed that for S≳O(1), the Rossby modes are severely damped, and it is only at small S, and during the early stages, that the presence of these wave modes was evident. These observations are supported by the theory, which shows the damping factors increase with S and are numerically large for S≳O(1)

  16. Centrifugal force induced by relativistically rotating spheroids and cylinders

    NASA Astrophysics Data System (ADS)

    Katz, Joseph; Lynden Bell, Donald; Bičák, Jiří

    2011-03-01

    Starting from the gravitational potential of a Newtonian spheroidal shell we discuss electrically charged rotating prolate spheroidal shells in the Maxwell theory. In particular we consider two confocal charged shells which rotate oppositely in such a way that there is no magnetic field outside the outer shell. In the Einstein theory we solve the Ernst equations in the region where the long prolate spheroids are almost cylindrical; in equatorial regions the exact Lewis 'rotating cylindrical' solution is so derived by a limiting procedure from a spatially bound system. In the second part we analyze two cylindrical shells rotating in opposite directions in such a way that the static Levi-Civita metric is produced outside and no angular momentum flux escapes to infinity. The rotation of the local inertial frames in flat space inside the inner cylinder is thus exhibited without any approximation or interpretational difficulties within this model. A test particle within the inner cylinder kept at rest with respect to axes that do not rotate as seen from infinity experiences a centrifugal force. Although in suitably chosen axes the spacetime there is exactly Minkowskian out to the inner cylinder, nevertheless, those inertial frame axes rotate with respect to infinity, so relative to the inertial frame inside the inner cylinder a test particle is traversing a circular orbit.

  17. Prototype Radiation Detector Positioning System For The Automated Nondestructive Assay Of Uf6 Cylinders

    SciTech Connect

    Hatchell, Brian K.; Valdez, Patrick LJ; Orton, Christopher R.; Mace, Emily K.

    2011-08-07

    International Atomic Energy Agency (IAEA) inspectors currently perform periodic inspections at uranium enrichment plants to verify UF6 cylinder enrichment declarations. Measurements are typically performed with handheld high-resolution sensors on a sampling of cylinders taken to be representative of the facility’s entire cylinder inventory. These measurements are time-consuming, expensive, and assay only a small fraction of the total cylinder volume. An automated nondestructive assay system capable of providing enrichment measurements over the full volume of the cylinder could improve upon current verification practices in terms of efficiency and assay accuracy. This paper describes an approach denoted the Integrated Cylinder Verification Station (ICVS) that supports 100% cylinder verification, provides volume-averaged cylinder enrichment assay, and reduces inspector manpower needs. To allow field measurements to be collected to validate data collection algorithms, a prototype radiation detector positioning system was constructed. The system was designed to accurately position an array of radiation detectors along the length of a cylinder to measure UF6 enrichment. A number of alternative radiation shields for the detectors were included with the system. A collimated gamma-ray spectrometer module that allows translation of the detectors in the surrounding shielding to adjust the field of view, and a collimating plug in the end to further reduce the low-energy field of view, were also developed. Proof-of-principle measurements of neutron and high-energy gamma-ray signatures, using moderated neutron detectors and large-volume spectrometers in a fixed-geometry, portal-like configuration, supported an early assessment of the viability of the concept. The system has been used successfully on two testing campaigns at an AREVA fuel fabrication plant to scan over 30 product cylinders. This paper will describe the overall design of the detector positioning system and

  18. Cost comparison of small gas turbines versus electric motors in a variable load industrial application

    NASA Astrophysics Data System (ADS)

    Desai, T. M.; Salama, S. Y.

    1984-07-01

    Equipment such as pumps and blowers can save a substantial amount of energy when operated at part-loads with a variable speed drive in comparison to the conventional technology of using a constant speed drive and a throttle valve. Gas turbines and electrical motors, with and without variable frequency speed controller, for one such industrial application are compared. The application characteristics are developed after reviewing the published population data for motors and gas turbines. Two types of gas turbines, simple cycle and regenerative cycle, and three types of motors, standard, high efficiency, and high efficiency with variable frequency speed controller, are considered. The total life-cycle costs of these five prime movers are compared for three scenarios with varying extent of part-load operations.

  19. Methods for forming small-volume electrical contacts and material manipulations with fluid microchannels

    DOEpatents

    Jacobson, Stephen C.; Ramsey, J. Michael; Culbertson, Christopher T.; Whitten, William B.; Foote, Robert S.

    2011-12-27

    A microfabricated device employing a bridging membrane and methods for electrokinetic transport of a liquid phase biological or chemical material using the same are described. The bridging membrane is deployed in or adjacent to a microchannel and permits either ionic current flow or the transport of gas species, while inhibiting the bulk flow of material. The use of bridging membranes in accordance with this invention is applicable to a variety of processes, including electrokinetically induced pressure flow in a region of a microchannel that is not influenced by an electric field, sample concentration enhancement and injection, as well as improving the analysis of materials where it is desired to eliminate electrophoretic bias. Other applications of the bridging membranes according to this invention include the separation of species from a sample material, valving of fluids in a microchannel network, mixing of different materials in a microchannel, and the pumping of fluids.

  20. Methods for forming small-volume electrical contacts and material manipulations with fluidic microchannels

    SciTech Connect

    Jacobson, Stephen C.; Ramsey, J. Michael; Culbertson, Christopher T.; Whitten, William B.; Foote, Robert S.

    2011-04-26

    A microfabricated device employing a bridging membrane and methods for electrokinetic transport of a liquid phase biological or chemical material using the same are described. The bridging membrane is deployed in or adjacent to a microchannel and permits either ionic current flow or the transport of gas species, while inhibiting the bulk flow of material. The use of bridging membranes in accordance with this invention is applicable to a variety of processes, including electrokinetically induced pressure flow in a region of a microehannel that is not influenced by an electric field, sample concentration enhancement and injection, as well as improving the analysis of materials where it is desired to eliminate electrophoretic bias. Other applications of the bridging membranes according to this invention include the separation of species from a sample material, valving of fluids in a microchannel network, mixing of different materials in a microchannel, and the pumping of fluids.

  1. Methods for forming small-volume electrical contacts and material manipulations with fluidic microchannels

    SciTech Connect

    Jacobson, Stephen C.; Ramsey, J. Michael; Culbertson, Christopher T.; Whitten, William B.; Foote, Robert S.

    2011-03-22

    A microfabricated device employing a bridging membrane and methods for electrokinetic transport of a liquid phase biological or chemical material using the same are described. The bridging membrane is deployed in or adjacent to a microchannel and permits either ionic current flow or the transport of gas species, while inhibiting the bulk flow of material. The use of bridging membranes in accordance with this invention is applicable to a variety of processes, including electrokinetically induced pressure flow in a region of a microchannel that is not influenced by an electric field, sample concentration enhancement and injection, as well as improving the analysis of materials where it is desired to eliminate electrophoretic bias. Other applications of the bridging membranes according to this invention include the separation of species from a sample material, valving of fluids in a microchannel network, mixing of different materials in a microchannel, and the pumping of fluids.

  2. Methods for forming small-volume electrical contacts and material manipulations with fluidic microchannels

    DOEpatents

    Jacobson, Stephen C.; Ramsey, J. Michael; Culbertson, Christopher T.; Whitten, William B.; Foote, Robert S.

    2004-02-03

    A microfabricated device employing a bridging membrane and methods for electrokinetic transport of a liquid phase biological or chemical material using the same are described. The bridging membrane is deployed in or adjacent to a microchannel and permits either ionic current flow or the transport of gas species, while inhibiting the bulk flow of material. The use of bridging membranes in accordance with this invention is applicable to a variety of processes, including electrokinetically induced pressure flow in a region of a microchannel that is not influenced by an electric field, sample concentration enhancement and injection, as well as improving the analysis of materials where it is desired to eliminate electrophoretic bias. Other applications of the bridging membranes according to this invention include the separation of species from a sample material, valving of fluids in a microchannel network, mixing of different materials in a microchannel, and the pumping of fluids.

  3. Methods for forming small-volume electrical contacts and material manipulations with fluidic microchannels

    DOEpatents

    Jacobson, Stephen C.; Ramsey, J. Michael

    2007-11-20

    A microfabricated device employing a bridging membrane and methods for electrokinetic transport of a liquid phase biological or chemical material using the same are described. The bridging membrane is deployed in or adjacent to a microchannel and permits either ionic current flow or the transport of gas species, while inhibiting the bulk flow of material. The use of bridging membranes in accordance with this invention is applicable to a variety of processes, including electrokinetically induced pressure flow in a region of a microchannel that is not influenced by an electric field, sample concentration enhancement and injection, as well as improving the analysis of materials where it is desired to eliminate electrophoretic bias. Other applications of the bridging membranes according to this invention include the separation of species from a sample material, valving of fluids in a microchannel network, mixing of different materials in a microchannel, and the pumping of fluids.

  4. Potential Application of Electrical Signature Analysis Methods for Monitoring Small Modular Reactor Components

    SciTech Connect

    Damiano, Brian; Tucker Jr, Raymond W; Haynes, Howard D

    2010-01-01

    This paper will describe the technical basis behind ESA and why we consider it a viable SMR condition monitoring technology. Concepts are presented of how ESA could be applied to monitor two candidate small modular reactor components: the main coolant pumps and the control rod drives. We believe the general health of these two components can be monitored and trended over time, using ESA methods. Our optimism is based on over two decades of ESA development and testing on a wide variety of components and systems, many of which have similar operational features to the main coolant pumps and control rod drives.

  5. A study of mass production and installation of small solar thermal electric power systems

    NASA Technical Reports Server (NTRS)

    Butterfield, J. F.

    1980-01-01

    Technological constraints, materials availability, production capacity, and manufacturing and installations plans and costs at different production levels are included in a study of concentrating collector industrialization. As cobalt for the engine and receiver is supply limited, alternative lower temperature alloys and higher temperature materials such as ceramics are discussed. Economics and production efficiency favor co-location of cellular and thin glass production for reflectors. Assembly and installation are expensive for small sites and few alternatives exist to apply mass production techniques to lower these costs for the selected design. Stepping motors in the size and quantities required are not commercially available today but could be in the future.

  6. In situ small angle neutron scattering revealing ion sorption in microporous carbon electrical double layer capacitors.

    PubMed

    Boukhalfa, Sofiane; Gordon, Daniel; He, Lilin; Melnichenko, Yuri B; Nitta, Naoki; Magasinski, Alexandre; Yushin, Gleb

    2014-03-25

    Experimental studies showed the impact of the electrolyte solvents on both the ion transport and the specific capacitance of microporous carbons. However, the related structure-property relationships remain largely unclear and the reported results are inconsistent. The details of the interactions of the charged carbon pore walls with electrolyte ions and solvent molecules at a subnanometer scale are still largely unknown. Here for the first time we utilize in situ small angle neutron scattering (SANS) to reveal the electroadsorption of organic electrolyte ions in carbon pores of different sizes. A 1 M solution of tetraethylammonium tetrafluoroborate (TEATFB) salt in deuterated acetonitrile (d-AN) was used in an activated carbon with the pore size distribution similar to that of the carbons used in commercial double layer capacitors. In spite of the incomplete wetting of the smallest carbon pores by the d-AN, we observed enhanced ion sorption in subnanometer pores under the applied potential. Such results suggest the visible impact of electrowetting phenomena counterbalancing the high energy of the carbon/electrolyte interface in small pores. This behavior may explain the characteristic butterfly wing shape of the cyclic voltammetry curve that demonstrates higher specific capacitance at higher applied potentials, when the smallest pores become more accessible to electrolyte. Our study outlines a general methodology for studying various organic salts-solvent-carbon combinations.

  7. Electric fields associated with small-scale magnetic holes in the plasma sheet: Evidence for electron currents

    NASA Astrophysics Data System (ADS)

    Goodrich, Katherine A.; Ergun, Robert E.; Stawarz, Julia E.

    2016-06-01

    We report observations of magnetic holes (MHs) in the near-Earth (8 RE to 12 RE) plasma sheet that have physical sizes perpendicular to the magnetic field (B) on the order of the ion Larmor radius (ρi) and, more importantly, have current layers less than ρi in thickness. Small-scale MHs can have >90% depletion in |B| and are commonly associated with the braking of bursty bulk flow events. The generation of MHs is often attributed to magnetohydrodynamic (MHD) instabilities, which requires a size greater than ρi; the depletion in |B| is from an ion current consistent with a pressure gradient. Electric field (E) observations indicate a negative potential inside of small-scale MHs that creates an outward E at the boundary, which drives an E × B electron current in a thin layer. These observations indicate that a Hall electron current is primarily responsible for the depletion of |B| in small-scale magnetic holes, rather than the ion pressure gradient.

  8. Physical properties of small water clusters in low and moderate electric fields

    NASA Astrophysics Data System (ADS)

    Acosta-Gutiérrez, S.; Hernández-Rojas, J.; Bretón, J.; Llorente, J. M. Gomez; Wales, D. J.

    2011-09-01

    Likely candidates for the lowest minima of water clusters (H2O)N for N ⩽ 20 interacting with a uniform electric field strength in the range E ⩽ 0.6 V/Å have been identified using basin-hopping global optimization. Two water-water model potentials were considered, namely TIP4P and the polarizable Dang-Chang potential. The two models produce some consistent results but also exhibit significant differences. The cluster internal energy and dipole moment indicate two varieties of topological transition in the structure of the global minimum as the field strength is increased. The first takes place at low field strengths (0.1 V/Å 10) usually forming helical structures.

  9. Fire testing of bare uranium hexafluoride cylinders

    SciTech Connect

    Pryor, W.A.

    1991-12-31

    In 1965, the Oak Ridge Gaseous Diffusion Plant (ORGDP), now the K-25 Site, conducted a series of tests in which bare cylinders of uranium hexafluoride (UF{sub 6}) were exposed to engulfing oil fires for the US Atomic Energy Commission (AEC), now the US Department of Energy (DOE). The tests are described and the results, conclusions, and observations are presented. Two each of the following types of cylinders were tested: 3.5-in.-diam {times} 7.5-in.-long cylinders of Monel (Harshaw), 5.0-in.-diam {times} x 30-in.-long cylinders of Monel, and 8-in.-diam {times} 48-in.-long cylinders of nickel. The cylinders were filled approximately to the standard UF{sub 6} fill limits of 5, 55, and 250 lb, respectively, with a U-235 content of 0.22%. The 5-in.- and 8-in.-diam cylinders were tested individually with and without their metal valve covers. For the 3.5-in.-diam Harshaw cylinders and the 5.0-in.-diam cylinder without a valve cover, the valves failed and UF{sub 6} was released. The remaining 6 cylinders ruptured explosively in time intervals ranging from about 8.5 to 11 min.

  10. Fire testing of bare uranium hexafluoride cylinders

    SciTech Connect

    Pryor, W.A.

    1991-12-31

    In 1965, the Oak Ridge Gaseous Diffusion Plant (ORGDP), now the K-25 Site, conducted a series of tests in which bare cylinders of uranium hexafluoride (UF{sub 6}) were exposed to engulfing oil fires for the US Atomic Energy Commission (AEC), now the US Department of Energy (DOE). The tests are described and the results, conclusions, and observations are presented. Two each of the following types of cylinders were tested: 3.5-in.-diam {times} 7.5-in.-long cylinders of Monel (Harshaw), 5.0-in.-diam {times} 30-in.-long cylinders of Monel, and 8-in.-diam {times} 48-in.-long cylinders of nickel. The cylinders were filled approximately to the standard UF{sub 6} fill limits of 5, 55, and 250 lb, respectively, with a U-235 content of 0.22%. The 5-in.- and 8-in.-diam cylinders were tested individually with and without their metal valve covers. For the 3.5-in.-diam Harshaw cylinders and the 5.0-in.-diam cylinder without a valve cover the valves failed and UF{sub 6} was released. The remaining cylinders ruptured explosively in time intervals ranging from about 8.5 to 11 min.

  11. A Device for Precision Neutralization of Electric Charge of Small Drops Using Ionized Air

    SciTech Connect

    Fan, Sewan

    2003-03-17

    For use in our Millikan type liquid drop searches for fractional charge elementary particles we have developed a simple ionized air device for neutralizing a narrow stream of small drops. The neutralizer has been used for drops ranging in diameter from 10 to 25 {micro}m. The width of the produced charge distribution is given by the Boltzmann equilibrium charge distribution and the mean of the distribution is set by a bias voltage. Using the bias voltage, the mean can be set with a precision of better than e, the electron charge. The use of the neutralizer is illustrated in an application to mineral oil drops produced with charges of the order of 1000e. We also show the interesting case of silicone oil drops that are produced in our drop generator with a charge distribution narrower than the Boltzmann equilibrium charge distribution, the charge distribution being broadened by the neutralizer.

  12. The Study and Implementation of Electrically Small Printed Antennas for an Integrated Transceiver Design

    SciTech Connect

    Speer, Pete

    2009-04-28

    This work focuses on the design and evaluation of the inverted-F, meandering-monopole, and loop antenna geometries. These printed antennas are studied with the goal of identifying which is suitable for use in a miniaturized transceiver design and which has the ability to provide superior performance using minimal Printed Circuit Board (PCB) space. As a result, the main objective is to characterize tradeoffs and identify which antenna provides the best compromise among volume, bandwidth and efficiency. For experimentation purposes, three types of meandering-monopole antenna are examined resulting in five total antennas for the study. The performance of each antenna under study is evaluated based upon return loss, operational bandwidth, and radiation pattern characteristics. For our purposes, return loss is measured using the S11-port reflection coefficient which helps to characterize how well the small antenna is able to be efficiently fed. Operational bandwidth is measured as the frequency range over which the antenna maintains 2:1 Voltage Standing Wave Ratio (VSWR) or equivalently has 10-dB return loss. Ansoft High Frequency Structure Simulator (HFSS) is used to simulate expected resonant frequency, bandwidth, VSWR, and radiation pattern characteristics. Ansoft HFSS simulation is used to provide a good starting point for antenna design before actual prototype are built using an LPKF automated router. Simulated results are compared with actual measurements to highlight any differences and help demonstrate the effects of antenna miniaturization. Radiation characteristics are measured illustrating how each antenna is affected by the influence of a non-ideal ground plane. The antenna with outstanding performance is further evaluated to determine its maximum range of communication. Each designs range performance is evaluated using a pair of transceivers to demonstrate round-trip communication. This research is intended to provide a knowledge base which will help

  13. Electrical properties of diluted n- and p-Si{sub 1−x}Ge{sub x} at small x

    SciTech Connect

    Emtsev, V. V.; Abrosimov, N. V.; Kozlovskii, V. V.; Oganesyan, G. A.

    2014-12-15

    Hall effect and conductivity measurements are taken on Si{sub 1−x}Ge{sub x} of n- and p-type at x ≤ 0.05. Much attention is given to electrical measurements over a temperature interval of 25 to 40 K where the mobility of charged carriers is strongly affected by alloy scattering. The partial mobility of electrons and holes due to this scattering mechanism is estimated for n-Si{sub 1−x}Ge{sub x} and p-Si{sub 1−x}Ge{sub x} at small x. Together with this, an effect of the presence of Ge atoms upon the ionization energy of phosphorus and boron impurities is investigated. Some points related to an inhomogeneous distribution of Ge atoms in Si{sub 1−x}Ge{sub x} are discussed.

  14. Small solar electric system components demonstration. [thermal storage modules for Brayton systems

    NASA Technical Reports Server (NTRS)

    1980-01-01

    The design and testing of high temperature thermal storage modules (TSM) are reported. The test goals were to demonstrate the thermocline propagation in the TSM, to measure the steepness of the thermocline, and to measure the effectiveness of the TSM when used in a Brayton system. In addition, a high temperature valve suitable for switching the TSM at temperatures to 1700 F is described and tested. Test results confirm the existence of a sharp thermocline under design conditions. The thermal profile was steeper than expected and was insensitive to air density over the range of the test conditions. Experiments were performed which simulated the airflow of a small Brayton engine, 20 KWe, having a pair of thermal storage modules acting as efficient recuperators. Low pressure losses, averaging 12 inches of water, and high effectiveness, 93% for a 15 minute switching cycle, were measured. The insulation surrounding the ceramic core limited thermal losses to approximately 1 KWt. The hot valve was operated over 100 cycles and performed well at temperatures up to 1700 F.

  15. The Electric and Optical Properties of Doped Small Molecular Organic Light-Emitting Devices

    SciTech Connect

    Kwang-Ohk Cheon

    2003-08-05

    Organic light-emitting devices (OLEDs) constitute a new and exciting emissive display technology. In general, the basic OLED structure consists of a stack of fluorescent organic layers sandwiched between a transparent conducting-anode and metallic cathode. When an appropriate bias is applied to the device, holes are injected from the anode and electrons from the cathode; some of the recombination events between the holes and electrons result in electroluminescence (EL). Until now, most of the efforts in developing OLEDs have focused on display applications, hence on devices within the visible range. However some organic devices have been developed for ultraviolet or infrared emission. Various aspects of the device physics of doped small molecular OLEDs were described and discussed. The doping layer thickness and concentration were varied systematically to study their effects on device performances, energy transfer, and turn-off dynamics. Low-energy-gap DCM2 guest molecules, in either {alpha}-NPD or DPVBi host layers, are optically efficient fluorophores but also generate deep carrier trap-sites. Since their traps reduce the carrier mobility, the current density decreases with increased doping concentration. At the same time, due to efficient energy transfer, the quantum efficiency of the devices is improved by light doping or thin doping thickness, in comparison with the undoped neat devices. However, heavy doping induces concentration quenching effects. Thus, the doping concentration and doping thickness may be optimized for best performance.

  16. Solid State Digital Propulsion "Cluster Thrusters" For Small Satellites Using High Performance Electrically Controlled Extinguishable Solid Propellants (ECESP)

    NASA Technical Reports Server (NTRS)

    Sawka, Wayne N.; Katzakian, Arthur; Grix, Charles

    2005-01-01

    Electrically controlled extinguishable solid propellants (ESCSP) are capable of multiple ignitions, extinguishments and throttle control by the application of electrical power. Both core and end burning no moving parts ECESP grains/motors to three inches in diameter have now been tested. Ongoing research has led to a newer family of even higher performance ECESP providing up to 10% higher performance, manufacturing ease, and significantly higher electrical conduction. The high conductivity was not found to be desirable for larger motors; however it is ideal for downward scaling to micro and pico- propulsion applications with a web thickness of less than 0.125 inch/ diameter. As a solid solution propellant, this ECESP is molecularly uniform, having no granular structure. Because of this homogeneity and workable viscosity it can be directly cast into thin layers or vacuum cast into complex geometries. Both coaxial and grain stacks have been demonstrated. Combining individual propellant coaxial grains and/or grain stacks together form three-dimensional arrays yield modular cluster thrusters. Adoption of fabless manufacturing methods and standards from the electronics industry will provide custom, highly reproducible micro-propulsion arrays and clusters at low costs. These stack and cluster thruster designs provide a small footprint saving spacecraft surface area for solar panels and/or experiments. The simplicity of these thrusters will enable their broad use on micro-pico satellites for primary propulsion, ACS and formation flying applications. Larger spacecraft may find uses for ECESP thrusters on extended booms, on-orbit refueling, pneumatic actuators, and gas generators.

  17. Multiplex in-cylinder pressure measurement utilizing an optical fiber with specific refractive-index composition.

    PubMed

    Komachiya, M; Sonobe, H; Oho, S; Kurita, M; Nakazawa, T; Sasayama, T

    1996-03-01

    An approach to multiplex in-cylinder pressure measurement that utilizes a single-mode optical fiber with specific refractive-index composition has been proposed. The sensing fiber has been designed to show a certain amount of optical power loss with a small change in the fiber-local-bend radius. Along with pressure-transferring diaphragms the sensing fiber was embedded into the head gasket of a four-cylinder gasoline engine. The internal-pressure change in each combustion chamber was detected on the basis of bending power loss in the fiber. Combustion pressure peaks for each cylinder were clearly observed.

  18. On vortex shedding from a hexagonal cylinder

    NASA Astrophysics Data System (ADS)

    Khaledi, Hatef A.; Andersson, Helge I.

    2011-10-01

    The unsteady wake behind a hexagonal cylinder in cross-flow is investigated numerically. The time-dependent three-dimensional Navier-Stokes equations are solved for three different Reynolds numbers Re and for two different cylinder orientations. The topology of the vortex shedding depends on the orientation and the Strouhal frequency is generally higher in the wake of a face-oriented cylinder than behind a corner-oriented cylinder. For both orientations a higher Strouhal number St is observed when Re is increased from 100 to 500 whereas St is unaffected by a further increase up to Re=1000. The distinct variation of St with the orientation of the hexagonal cylinder relative to the oncoming flow is opposite of earlier findings for square cylinder wakes which exhibited a higher St with corner orientation than with face orientation.

  19. Two-stroke multi-cylinder engine

    SciTech Connect

    Okumura, S.; Hakamata, K.

    1988-11-29

    This patent describes an internal combustion engine having a pair of cylinder bores disposed at an angle to each other, pistons reciprocating in the cylinder bores, a crankshaft supported for rotation about an axis relative to the cylinder bores, connecting rods for transferring reciprocation of the pistons into rotation of the crankshaft, the connection between the pistons and the connecting rods being such that a side thrust is exerted on the pistons for causing the pistons to tilt in the cylinder bores during the power strokes of the pistons, and exhaust ports opening into the cylinder bores at one side of a plane passing through the respective cylinder bore axis and parallel to the crankshaft rotational axis, the improvement comprising each of the exhaust ports opening through the same side of the respective plane with respect to the direction of rotation of the crankshaft.

  20. A new cylinder cooling system using oil

    SciTech Connect

    Harashina, Kenichi; Murata, Katsuhiro; Satoh, Hiroshi; Shimizu, Yasuo; Hamamura, Masahiro

    1995-12-31

    The design of engine cylinders must satisfy two conflicting requirements, good cooling performance and ease of manufacture. A cooling system was designed to permit the circulation of engine lubricating oil as a coolant at high speed through grooves provided on the external periphery of the cylinder liner. Testing in an actual operating engine confirmed that this cooling system design not only provides better heat transfer and higher cooling performance but also simplifies the manufacturing of the cylinder since external cooling fins are not required. In this paper, the authors will discuss the cylinder cooling effect of the new cylinder cooling system, referring mainly to the test results of a single-cylinder motorcycle engine with lubricating oil from the crankcase used as the coolant.

  1. Cylinder valve packing nut studies

    SciTech Connect

    Blue, S.C.

    1991-12-31

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

  2. Flow in a torsionally oscillating filled cylinder

    NASA Technical Reports Server (NTRS)

    Schafer, C. F.

    1983-01-01

    The flow of a liquid in a completely filled cylinder undergoing torsional oscillations about its longitudinal symmetry axis was studied analytically and experimentally. The objective of the studies was to determine the efficacy of the torsional oscillations in mixing the confined liquid. Flow was found to be confined primarily to toroidal cells at the ends of the cylinder. Cell thickness was about equal to the cylinder radius. The use of baffles at the end walls was shown to enhance the mixing process.

  3. Electrical Thermometers for Aircraft

    NASA Technical Reports Server (NTRS)

    Peterson, John B; Womack, S H J

    1937-01-01

    Electrical thermometers commonly used on aircraft are the thermoelectric type for measuring engine-cylinder temperatures, the resistance type for measuring air temperatures, and the superheat meters of thermoelectric and resistance types for use on airships. These instruments are described and their advantages and disadvantages enumerated. Methods of testing these instruments and the performance to be expected from each are discussed. The field testing of engine-cylinder thermometers is treated in detail.

  4. Evaluating Interventions in the U.S. Electricity System: Assessments of Energy Efficiency, Renewable Energy, and Small-Scale Cogeneration

    NASA Astrophysics Data System (ADS)

    Siler-Evans, Kyle

    to evaluate the effects of an additional wind turbine or solar panel in the U.S. electricity system. I find that the most attractive sites for renewables depend strongly on one's objective. A solar panel in Iowa displaces 20% more CO2 emissions than a panel in Arizona, though energy production from the Iowa panel is 25% less. Similarly, despite a modest wind resource, a wind turbine in West Virginia is expected to displace 7 times more health and environmental damages than a wind turbine in Oklahoma. Finally, I shift focus and explore the economics of small-scale cogeneration, which has long been recognized as a more efficient alternative to central-station power. Although the benefits of distributed cogeneration are widely cited, adoption has been slow in the U.S. Adoption could be encouraged by making cogeneration more economically attractive, either by increasing the expected returns or decreasing the risks of such investments. I present a case study of a 300-kilowatt cogeneration unit and evaluate the expected returns from: demand response, capacity markets, regulation markets, accelerated depreciation, a price on CO2 emissions, and net metering. In addition, I explore the effectiveness of feed-in tariffs at mitigating the energy-price risks to cogeneration projects.

  5. Self-sustained criterion with photoionization for positive dc corona plasmas between coaxial cylinders

    SciTech Connect

    Zheng, Yuesheng; Zhang, Bo He, Jinliang

    2015-06-15

    The positive dc corona plasmas between coaxial cylinders in air under the application of a self-sustained criterion with photoionization are investigated in this paper. A photon absorption function suitable for cylindrical electrode, which can characterize the total photons within the ionization region, is proposed on the basis of the classic corona onset criteria. Based on the general fluid model with the self-sustained criterion, the role of photoionization in the ionization region is clarified. It is found that the surface electric field keeps constant under a relatively low corona current, while it is slightly weakened with the increase of the corona current. Similar tendencies can be found under different conductor radii and relative air densities. The small change of the surface electric field will become more significant for the electron density distribution as well as the ionization activity under a high corona current, compared with the results under the assumption of a constant surface field. The assumption that the surface electric field remains constant should be corrected with the increase of the corona current when the energetic electrons with a distance from the conductor surface are concerned.

  6. Hydrodynamic Force on a Cylinder Oscillating at Low Frequency

    NASA Technical Reports Server (NTRS)

    Berg, Robert F.; Yao, Minwu; Panzarella, Charles H.

    2007-01-01

    The hydrodynamic force on a cylinder oscillating transversely to its axis is a nonlinear function of the displacement amplitude x0. We report measurements and numerical calculations of the force at frequencies low enough that delta > R, where delta is the viscous penetration length and R is the cylinder radius. For small amplitudes, the numerically calculated Fourier transform of the force per unit length, F(sub small), agrees with Stokes' analytical calculation. For larger amplitudes, the force per unit length found by both calculation and measurement is F = F(sub small)C (x(sub 0)/delta,R/delta). The complex function C depends only weakly on R/delta, indicating that x0/delta is more appropriate as a scaling variable than the Keulegan-Carpenter number KC = pi*x(sub 0)/R. The measurements used a torsion oscillator driven at frequencies from 1 to 12 Hz while immersed in dense xenon. The oscillator comprised cylinders with an effective radius of R = 13.4 micron and oscillation amplitudes as large as x(sub 0)/delta = 4 (corresponding to KC as large as 71). The calculations used similar conditions except that the amplitudes were as large as x0/delta = 28.

  7. GLOBAL MONITORING OF URANIUM HEXIFLORIDE CYLINDERS NEXT STEPS IN DEVELOPMENT OF AN ACTION PLAN

    SciTech Connect

    Hanks, D.

    2010-06-09

    Over 40 industrial facilities world-wide use standardized uranium hexafluoride (UF{sub 6}) cylinders for transport, storage and in-process receiving in support of uranium conversion, enrichment and fuel fabrication processes. UF{sub 6} is processed and stored in the cylinders, with over 50,000 tU of UF{sub 6} transported each year in these International Organization for Standardization (ISO) qualified containers. Although each cylinder is manufactured to an ISO standard that calls for a nameplate with the manufacturer's identification number (ID) and the owner's serial number engraved on it, these can be quite small and difficult to read. Recognizing that each facility seems to use a different ID, a cylinder can have several different numbers recorded on it by means of metal plates, sticky labels, paint or even marker pen as it travels among facilities around the world. The idea of monitoring movements of UF{sub 6} cylinders throughout the global uranium fuel cycle has become a significant issue among industrial and safeguarding stakeholders. Global monitoring would provide the locations, movements, and uses of cylinders in commercial nuclear transport around the world, improving the efficiency of industrial operations while increasing the assurance that growing nuclear commerce does not result in the loss or misuse of cylinders. It should be noted that a unique ID (UID) attached to a cylinder in a verifiable manner is necessary for safeguarding needs and ensuring positive ID, but not sufficient for an effective global monitoring system. Modern technologies for tracking and inventory control can pair the UID with sensors and secure data storage for content information and complete continuity of knowledge over the cylinder. This paper will describe how the next steps in development of an action plan for employing a global UF{sub 6} cylinder monitoring network could be cultivated using four primary UID functions - identification, tracking, controlling, and accounting.

  8. Rotating cylinder design as a lifting generator

    NASA Astrophysics Data System (ADS)

    Asrokin, Azharrudin; Rizal Ramly, Mohammad; Halim Ahmad, Abdul

    2013-12-01

    The airfoil shape of a wing has always been the design to generate lift. But few realized that a simple rotating cylinder can also create lift. However, the explanation and study of how a rotating cylinder creates lift are still complex. In remote area where it is difficult for air vehicle to access, the exploration and discovery of different configuration for design concept is rather important. Due to this reason, there is a need to think of a lift generator that can produce better lift (few fold better than conventional airfoil) at lower speed to take off in a short distance of time. This paper will explain the conditions and the design of such a wing using the rotating cylinder concept that will take off in a short time and requires little takeoff and landing strip. Spokes will be attached to the cylinder to force the surrounding air to rotate along with the cylinder. This will create a vortex that hastens the speed of the air on top of the cylinder and at the same time retarding the speed of air below the cylinder. From the results, the rougher surface cylinder produces more lift when rotating and also, higher speed rotation of the cylinder greatly changes the speed of the surrounding air, thus better lift.

  9. A Visual Photographic Study of Cylinder Lubrication

    NASA Technical Reports Server (NTRS)

    Shaw, Milton C; Nussdorfer, Theodore

    1946-01-01

    A V-type engine provided with a glass cylinder was used to study visually the lubrication characteristics of an aircraft-type piston. Photographs and data were obtained with the engine motored at engine speeds up to 1000 r.p.m. and constant cylinder-head pressures of 0 and 50 pounds per square inch. A study was made of the orientation of the piston under various operating conditions, which indicated that the piston was inclined with the crown nearest the major-thrust cylinder face throughout the greater part of the cycle. The piston moved laterally in the cylinder under the influence of piston side thrust.

  10. Vortex motion behind a circular cylinder

    NASA Technical Reports Server (NTRS)

    Foeppl, L.

    1983-01-01

    Vortex motion behind a circular cylinder moving through water is discussed. It is shown that a pair of vortices form behind a moving cylinder and that their centers will move along a predictable curve. This curve represents an equilibrium condition which, however, is subject to perturbation. The stability of the vortex pair is investigated. Movement of the vortex pair away from the cylinder is calculated as an explanation of the resistance of the cylinder. Finally, the principles elaborated are applied to the flow around a flat plate.

  11. Monitoring of corrosion in ORGDP cylinder yards

    SciTech Connect

    Henson, H.M.; Frazier, J.L.; Barlow, C.R.; Ziehlke, K.T.

    1988-01-01

    Process tailings from US uranium isotope enrichment activities are stored in mild steel cylinders designed and manufactured according to ASME Boiler and Pressure Vessel Code criteria. Most storage facilities are open areas adjacent to the enrichment plants where the cylinders are exposed to weather; approximately 5000 cylinders are in several cylinder yards at the Oak Ridge Gaseous Diffusion Plant (ORGDP). Since mild steel will corrode under these storage conditions, significant work is being done to determine general corrosion behavior of tails cylinders and to estimate anticipated lifetimes. The program under way at the ORGDP is targeted at conditions specific to the Oak Ridge cylinder yards. The work includes (1) determination of the current conditions of cylinders stored in these yards, (2) description of rusting behavior in regions of the cylinders showing accelerated attack, (3) the monitoring of corrosion rates through periodic measurement of test coupons placed within the cylinder yards, and (4) establishment of a computer base to incorporate and retain these data. The information obtained will enhance planning for continuing safe storage of the tails materials. 8 refs., 6 figs.

  12. Overseas shipments of 48Y cylinders

    SciTech Connect

    Tanaka, R.T.; Furlan, A.S.

    1991-12-31

    This paper describes experiences with two incidents of overseas shipments of uranium hexafluoride (UF{sub 6}) cylinders. The first incident involved nine empty UF{sub 6} cylinders in enclosed sea containers. Three UF{sub 6} cylinders broke free from their tie-downs and damaged and contaminated several sea containers. This paper describes briefly how decontamination was carried out. The second incident involved a shipment of 14 full UF{sub 6} cylinders. Although the incident did not cause an accident, the potential hazard was significant. The investigation of the cause of the near accident is recounted. Recommendations to alleviate future similar incidents for both cases are presented.

  13. Fire exposure of empty 30B cylinders

    SciTech Connect

    Ziehlke, K.T.

    1991-12-31

    Cylinders for UF{sub 6} handling, transport, and storage are designed and built as unfired pressure vessels under ASME Boiler and Pressure Vessel Code criteria and standards. They are normally filled and emptied while UF{sub 6} is in its liquid phase. Transport cylinders such as the Model 30B are designed for service at 200 psi and 250{degrees}F, to sustain the process conditions which prevail during filling or emptying operations. While in transport, however, at ambient temperature the UF{sub 6} is solid, and the cylinder interior is well below atmospheric pressure. When the cylinders contain isotopically enriched product (above 1.0 percent U-235), they are transported in protective overpacks which function to guard the cylinders and their contents against thermal or mechanical damage in the event of possible transport accidents. Two bare Model 30B cylinders were accidentally exposed to a storage warehouse fire in which a considerable amount of damage was sustained by stored materials and the building structure, as well as by the cylinder valves and valve protectors. The cylinders were about six years old, and had been cleaned, inspected, hydrotested, and re-certified for service, but were still empty at the time of the fire. The privately-owned cylinders were transferred to DOE for testing and evaluation of the fire damage.

  14. Small-Scale Dust Structures in Halley's Coma: Evidence from the Vega-2 Electric Field Records

    NASA Astrophysics Data System (ADS)

    Oberc, P.

    1999-07-01

    Owing to simultaneous dust and plasma wave observations onboard the Vega mission to Comet Halley, previous studies have found that the two double probe antennas, short (of APV-N experiment) and long (APV-V), (i) responded to plasma clouds induced by impacts of relatively large particles, (ii) the target area was comparable to the whole spacecraft projection, and (iii) the mass thresholds depended on the ambient plasma conditions. Subsequently, the response mechanisms have been identified, and it was shown that if impacts became continuous, the sensitivity of the antennas to individual plasma clouds was reduced or even cancelled. In the present paper, about 30 short-time events of continuous impact (CIEs), recognized in the Vega-2 records from the two experiments mostly near the closest approach to (at ∼104 km from) the nucleus, are investigated. The high-resolution APV-N waveforms reveal that the respective dust formations were structured. A few types of structure, all belonging to one family, have been distinguished. The basic structure, as seen along the Vega-2 pass, is a sequence of particle clouds. CIEs have time scales shorter than or comparable to the time resolution of the dust experiments (spatial scale less than 200 km) and do not correlate with the SP-1 observations (m≤10-10 g) nor with the published SP-2 fluxes (m≤5.8×10-8 g). But, these dust data, combined with an integral criterion for continuous impact, provide a constraint which implies that the particles responsible were bigger than 10-9-10-8 g. The data from the DUCMA V-detector confirm positively this inference for about 1/3 (∼10) of CIEs and indicate that particles (much) bigger than 10-7 g were decisive in generating several other events. Using an argument from the dusty gas dynamics, it is shown that the small-scale dust structures were not jets but have originated from the disintegration of particle aggregates. An estimate of the total mass contained within a dust structure leads to

  15. Ultrastable low-noise current amplifier: A novel device for measuring small electric currents with high accuracy

    NASA Astrophysics Data System (ADS)

    Drung, D.; Krause, C.; Becker, U.; Scherer, H.; Ahlers, F. J.

    2015-02-01

    An ultrastable low-noise current amplifier (ULCA) is presented. The ULCA is a non-cryogenic instrument based on specially designed operational amplifiers and resistor networks. It involves two stages, the first providing a 1000-fold current gain and the second performing a current-to-voltage conversion via an internal 1 MΩ reference resistor or, optionally, an external standard resistor. The ULCA's transfer coefficient is highly stable versus time, temperature, and current amplitude within the full dynamic range of ±5 nA. The low noise level of 2.4 fA/√Hz helps to keep averaging times short at small input currents. A cryogenic current comparator is used to calibrate both input current gain and output transresistance, providing traceability to the quantum Hall effect. Within one week after calibration, the uncertainty contribution from short-term fluctuations and drift of the transresistance is about 0.1 parts per million (ppm). The long-term drift is typically 5 ppm/yr. A high-accuracy variant is available that shows improved stability of the input gain at the expense of a higher noise level of 7.5 fA/√Hz. The ULCA also allows the traceable generation of small electric currents or the calibration of high-ohmic resistors.

  16. Ultrastable low-noise current amplifier: A novel device for measuring small electric currents with high accuracy

    SciTech Connect

    Drung, D.; Krause, C.; Becker, U.; Scherer, H.; Ahlers, F. J.

    2015-02-15

    An ultrastable low-noise current amplifier (ULCA) is presented. The ULCA is a non-cryogenic instrument based on specially designed operational amplifiers and resistor networks. It involves two stages, the first providing a 1000-fold current gain and the second performing a current-to-voltage conversion via an internal 1 MΩ reference resistor or, optionally, an external standard resistor. The ULCA’s transfer coefficient is highly stable versus time, temperature, and current amplitude within the full dynamic range of ±5 nA. The low noise level of 2.4 fA/√Hz helps to keep averaging times short at small input currents. A cryogenic current comparator is used to calibrate both input current gain and output transresistance, providing traceability to the quantum Hall effect. Within one week after calibration, the uncertainty contribution from short-term fluctuations and drift of the transresistance is about 0.1 parts per million (ppm). The long-term drift is typically 5 ppm/yr. A high-accuracy variant is available that shows improved stability of the input gain at the expense of a higher noise level of 7.5 fA/√Hz. The ULCA also allows the traceable generation of small electric currents or the calibration of high-ohmic resistors.

  17. "Egg-Box"-Assisted Fabrication of Porous Carbon with Small Mesopores for High-Rate Electric Double Layer Capacitors.

    PubMed

    Kang, Danmiao; Liu, Qinglei; Gu, Jiajun; Su, Yishi; Zhang, Wang; Zhang, Di

    2015-11-24

    Here we report a method to fabricate porous carbon with small mesopores around 2-4 nm by simple activation of charcoals derived from carbonization of seaweed consisting of microcrystalline domains formed by the "egg-box" model. The existence of mesopores in charcoals leads to a high specific surface area up to 3270 m(2) g(-1), with 95% surface area provided by small mesopores. This special pore structure shows high adaptability when used as electrode materials for an electric double layer capacitor, especially at high charge-discharge rate. The gravimetric capacitance values of the porous carbon are 425 and 210 F g(-1) and volumetric capacitance values are 242 and 120 F cm(-3) in 1 M H2SO4 and 1 M TEA BF4/AN, respectively. The capacitances even remain at 280 F g(-1) (160 F cm(-3)) at 100 A g(-1) and 156 F g(-1) (90 F cm(-3)) at 50 A g(-1) in the aqueous and organic electrolytes, demonstrating excellent high-rate capacitive performance.

  18. Ultrastable low-noise current amplifier: a novel device for measuring small electric currents with high accuracy.

    PubMed

    Drung, D; Krause, C; Becker, U; Scherer, H; Ahlers, F J

    2015-02-01

    An ultrastable low-noise current amplifier (ULCA) is presented. The ULCA is a non-cryogenic instrument based on specially designed operational amplifiers and resistor networks. It involves two stages, the first providing a 1000-fold current gain and the second performing a current-to-voltage conversion via an internal 1 MΩ reference resistor or, optionally, an external standard resistor. The ULCA's transfer coefficient is highly stable versus time, temperature, and current amplitude within the full dynamic range of ±5 nA. The low noise level of 2.4 fA/√Hz helps to keep averaging times short at small input currents. A cryogenic current comparator is used to calibrate both input current gain and output transresistance, providing traceability to the quantum Hall effect. Within one week after calibration, the uncertainty contribution from short-term fluctuations and drift of the transresistance is about 0.1 parts per million (ppm). The long-term drift is typically 5 ppm/yr. A high-accuracy variant is available that shows improved stability of the input gain at the expense of a higher noise level of 7.5 fA/√Hz. The ULCA also allows the traceable generation of small electric currents or the calibration of high-ohmic resistors.

  19. Axisymmetric instability of the Poiseuille-Couette flow between concentric cylinders at high Reynolds numbers

    NASA Astrophysics Data System (ADS)

    Savenkov, I. V.

    2015-02-01

    For the pressure-driven flow in an annular channel with a wall moving in the axial direction, its linear instability with respect to axisymmetric perturbations at high Reynolds numbers is investigated within the framework of the triple-deck theory. When the gap between the cylinders is sufficiently small (as compared to the radii of the cylinders), it is shown that the perturbations can split into two wave packets, the first of which grows faster and moves at a higher velocity.

  20. Trade-offs Between Electricity Production from Small Hydropower Plants and Ecosystem Services in Alpine River Basins

    NASA Astrophysics Data System (ADS)

    Meier, Philipp; Schwemmle, Robin; Viviroli, Daniel

    2015-04-01

    The need for a reduction in greenhouse gas emissions and the decision to phase out nuclear power plants in Switzerland and Germany increases pressure to develop the remaining hydropower potential in Alpine catchments. Since most of the potential for large reservoirs is already exploited, future development focusses on small run-of-the-river hydropower plants (SHP). Being considered a relatively environment-friendly electricity source, investment in SHP is promoted through subsidies. However, SHP can have a significant impact on riverine ecosystems, especially in the Alpine region where residual flow reaches tend to be long. An increase in hydropower exploitation will therefore increase pressure on ecosystems. While a number of studies assessed the potential for hydropower development in the Alps, two main factors were so far not assessed in detail: (i) ecological impacts within a whole river network, and (ii) economic conditions under which electricity is sold. We present a framework that establishes trade-offs between multiple objectives regarding environmental impacts, electricity production and economic evaluation. While it is inevitable that some ecosystems are compromised by hydropower plants, the context of these impacts within a river network should be considered when selecting suitable sites for SHP. From an ecological point of view, the diversity of habitats, and therefore the diversity of species, should be maintained within a river basin. This asks for objectives that go beyond lumped parameters of hydrological alteration, but also consider habitat diversity and the spatial configuration. Energy production in run-of-the-river power plants depends on available discharge, which can have large fluctuations. In a deregulated electricity market with strong price variations, an economic valuation should therefore be based on the expected market value of energy produced. Trade-off curves between different objectives can help decision makers to define policies

  1. Internal combustion engine cylinder-to-cylinder balancing with balanced air-fuel ratios

    SciTech Connect

    Harris, Ralph E.; Bourn, Gary D.; Smalley, Anthony J.

    2006-01-03

    A method of balancing combustion among cylinders of an internal combustion engine. For each cylinder, a normalized peak firing pressure is calculated as the ratio of its peak firing pressure to its combustion pressure. Each cylinder's normalized peak firing pressure is compared to a target value for normalized peak firing pressure. The fuel flow is adjusted to any cylinder whose normalized peak firing pressure is not substantially equal to the target value.

  2. Synchrotron Radiation from a Charge Moving Along Helical Orbit around a Dielectric Cylinder

    NASA Astrophysics Data System (ADS)

    Saharian, A. A.; Kotanjyan, A. S.

    2010-04-01

    The radiation emitted by a charged particle moving along a helical orbit around a dielectric cylinder immersed in a homogeneous medium is investigated. Formulae are derived for the electromagnetic potentials, electric and magnetic fields, and for the spectral-angular distribution of the radiation in the exterior medium. It is shown that under the Cherenkov condition for dielectric permittivity of the cylinder and the velocity of the particle image on the cylinder surface, strong narrow peaks appear in the angular distribution for the number of radiated quanta. At these peaks the radiated energy exceeds the corresponding quantity for a homogeneous medium by some orders of magnitude. The results of numerical calculations for the angular distribution of radiated quanta are presented and they are compared with the corresponding quantities for radiation in a homogeneous medium. It is shown that the presence of the cylinder can increase essentially the radiation intensity.

  3. Projected Demand and Potential Impacts to the National Airspace System of Autonomous, Electric, On-Demand Small Aircraft

    NASA Technical Reports Server (NTRS)

    Smith, Jeremy C.; Viken, Jeffrey K.; Guerreiro, Nelson M.; Dollyhigh, Samuel M.; Fenbert, James W.; Hartman, Christopher L.; Kwa, Teck-Seng; Moore, Mark D.

    2012-01-01

    Electric propulsion and autonomy are technology frontiers that offer tremendous potential to achieve low operating costs for small-aircraft. Such technologies enable simple and safe to operate vehicles that could dramatically improve regional transportation accessibility and speed through point-to-point operations. This analysis develops an understanding of the potential traffic volume and National Airspace System (NAS) capacity for small on-demand aircraft operations. Future demand projections use the Transportation Systems Analysis Model (TSAM), a tool suite developed by NASA and the Transportation Laboratory of Virginia Polytechnic Institute. Demand projections from TSAM contain the mode of travel, number of trips and geographic distribution of trips. For this study, the mode of travel can be commercial aircraft, automobile and on-demand aircraft. NASA's Airspace Concept Evaluation System (ACES) is used to assess NAS impact. This simulation takes a schedule that includes all flights: commercial passenger and cargo; conventional General Aviation and on-demand small aircraft, and operates them in the simulated NAS. The results of this analysis projects very large trip numbers for an on-demand air transportation system competitive with automobiles in cost per passenger mile. The significance is this type of air transportation can enhance mobility for communities that currently lack access to commercial air transportation. Another significant finding is that the large numbers of operations can have an impact on the current NAS infrastructure used by commercial airlines and cargo operators, even if on-demand traffic does not use the 28 airports in the Continental U.S. designated as large hubs by the FAA. Some smaller airports will experience greater demand than their current capacity allows and will require upgrading. In addition, in future years as demand grows and vehicle performance improves other non-conventional facilities such as short runways incorporated into

  4. The control of a parallel hybrid-electric propulsion system for a small unmanned aerial vehicle using a CMAC neural network.

    PubMed

    Harmon, Frederick G; Frank, Andrew A; Joshi, Sanjay S

    2005-01-01

    A Simulink model, a propulsion energy optimization algorithm, and a CMAC controller were developed for a small parallel hybrid-electric unmanned aerial vehicle (UAV). The hybrid-electric UAV is intended for military, homeland security, and disaster-monitoring missions involving intelligence, surveillance, and reconnaissance (ISR). The Simulink model is a forward-facing simulation program used to test different control strategies. The flexible energy optimization algorithm for the propulsion system allows relative importance to be assigned between the use of gasoline, electricity, and recharging. A cerebellar model arithmetic computer (CMAC) neural network approximates the energy optimization results and is used to control the parallel hybrid-electric propulsion system. The hybrid-electric UAV with the CMAC controller uses 67.3% less energy than a two-stroke gasoline-powered UAV during a 1-h ISR mission and 37.8% less energy during a longer 3-h ISR mission.

  5. Role of activation of cholinergic influences in recovery of electrical activity of the stomach and small intestine during the early postoperative period in rats.

    PubMed

    Tropskaya, N S; Solov'yova, G I; Popova, T S

    2007-02-01

    The effects of neostigmine and calcium pantothenate on electrical activity of the stomach and small intestine were studied in chronic experiments on rats after laparotomy with implantation of a probe into the jejunum and electrodes into different portions of the gastrointestinal tract. At the early terms after surgery, stimulation of endogenous acetylcholine release intensified electrical activity of the stomach, duodenum, and jejunum. Treatment with neostigmine and calcium pantothenate did not accelerate the recovery of the migrating myoelectrical complex, but promoted the recovery of the general intensity of action potential generation in the stomach and small intestine. PMID:17970199

  6. Sub-grid drag models for horizontal cylinder arrays immersed in gas-particle multiphase flows

    SciTech Connect

    Sarkar, Avik; Sun, Xin; Sundaresan, Sankaran

    2013-09-08

    Immersed cylindrical tube arrays often are used as heat exchangers in gas-particle fluidized beds. In multiphase computational fluid dynamics (CFD) simulations of large fluidized beds, explicit resolution of small cylinders is computationally infeasible. Instead, the cylinder array may be viewed as an effective porous medium in coarse-grid simulations. The cylinders' influence on the suspension as a whole, manifested as an effective drag force, and on the relative motion between gas and particles, manifested as a correction to the gas-particle drag, must be modeled via suitable sub-grid constitutive relationships. In this work, highly resolved unit-cell simulations of flow around an array of horizontal cylinders, arranged in a staggered configuration, are filtered to construct sub-grid, or `filtered', drag models, which can be implemented in coarse-grid simulations. The force on the suspension exerted by the cylinders is comprised of, as expected, a buoyancy contribution, and a kinetic component analogous to fluid drag on a single cylinder. Furthermore, the introduction of tubes also is found to enhance segregation at the scale of the cylinder size, which, in turn, leads to a reduction in the filtered gas-particle drag.

  7. Influence of the exhaust system on performance of a 4-cylinder supercharged engine

    SciTech Connect

    Trenc, F.; Bizjan, F.; Hribernik, A.

    1998-10-01

    Twin entry radial turbines are mostly used to drive compressors of small and medium size 6-cylinder diesel engines where the available energy of the undisturbed exhaust pulses can be efficiently used to drive the turbine of a turbocharger. Three selected cylinders feed two separated manifold branches and two turbine inlets and prevent negative interaction of pressure waves and its influence on the scavenging process of the individual cylinders. In the case of a four-stroke, 4-cylinder engine, two selected cylinders, directed by the firing order, can be connected to one (of the two) separated manifold branches that feeds one turbine entry. Good utilization of the pressure pulse energy, together with typically longer periods of reduced exhaust flow can lead to good overall efficiency of the two-pulse system. Sometimes this system can be superior to the single manifold system with four cylinders connected to one single-entry turbine. The paper describes advantages and disadvantages of the above described exhaust systems applied to a turbocharged and aftercooled 4-cylinder Diesel engine. Comparisons supported by the analyses of the numerical and experimental results are also given in the presented paper.

  8. Flow Instability Past A Rounded Cylinder

    NASA Astrophysics Data System (ADS)

    Park, Doohyun; Yang, Kyung-Soo

    2014-11-01

    Numerical simulation of flow past a rounded cylinder has been performed to study the effects of rounding corners of an angulated cylinder on the primary (2D) and the secondary (3D) instabilities associated with the corresponding flow configuration. We consider the rounded cylinders ranging from a square cylinder of height D to a circular cylinder of diameter D by rounding the four corners of a square cylinder with a quarter circle of fixed radius (r) . An immersed boundary method was adopted for implementation of the cylinder cross-sections in a Cartesian grid system. The key parameters are Reynolds number (Re) and corner radius of curvature (r) . Firstly, the characteristics of the primary instability such as critical Reynolds number (Rec) , force coefficients, and Strouhal number for vortex shedding are reported against r. It was found that Rec is maximum at r / D = 0.25, meaning that this flow is more stable than the two extreme cases of the square and circular cylinders. Furthermore, there are the optimal values of r / D for force coefficients, which vary with Re. Secondly, we studied the onset of 3D instabilities by using Floquet stability analysis. It turned out that the criticalities of 3D instability modes are significantly affected by r. This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIP) (No. 2012R1A2A2A01013019).

  9. A Convenient Storage Rack for Graduated Cylinders

    ERIC Educational Resources Information Center

    Love, Brian

    2004-01-01

    An attempt is made to find a solution to the occasional problem of a need for storing large numbers of graduated cylinders in many teaching and research laboratories. A design, which involves the creation of a series of parallel channels that are used to suspend inverted graduated cylinders by their bases, is proposed.

  10. Efficient visual grasping alignment for cylinders

    NASA Technical Reports Server (NTRS)

    Nicewarner, Keith E.; Kelley, Robert B.

    1991-01-01

    Monocular information from a gripper-mounted camera is used to servo the robot gripper to grasp a cylinder. The fundamental concept for rapid pose estimation is to reduce the amount of information that needs to be processed during each vision update interval. The grasping procedure is divided into four phases: learn, recognition, alignment, and approach. In the learn phase, a cylinder is placed in the gripper and the pose estimate is stored and later used as the servo target. This is performed once as a calibration step. The recognition phase verifies the presence of a cylinder in the camera field of view. An initial pose estimate is computed and uncluttered scan regions are selected. The radius of the cylinder is estimated by moving the robot a fixed distance toward the cylinder and observing the change in the image. The alignment phase processes only the scan regions obtained previously. Rapid pose estimates are used to align the robot with the cylinder at a fixed distance from it. The relative motion of the cylinder is used to generate an extrapolated pose-based trajectory for the robot controller. The approach phase guides the robot gripper to a grasping position. The cylinder can be grasped with a minimal reaction force and torque when only rough global pose information is initially available.

  11. Balancer structure for three-cylinder engines

    SciTech Connect

    Suzuki, T.

    1987-04-21

    This patent describes a balancer structure for a three-cylinder in-line engine having three cylinders, the latter comprising a first and third cylinder and a second cylinder disposed between the first and third cylinders, a crankshaft having crank arms disposed at angles of 120/sup 0/ with respect to each other and operatively connected to a piston assembly within each of the cylinders, respectively, consisting of: a single crankshaft adjacent and parallel to and rotated at the same speed as the crankshaft but in the opposite direction, means comprising first counterweights securely mounted on the crankshaft only at positions thereof corresponding to the first and third cylinders for balancing of a part of inertia forces of rotating masses and a part of inertia forces of reciprocating masses; means comprising at least one second counterweight securely mounted on the crankshaft substantially opposite to the crank arm corresponding to the second cylinder for balancing of the remainder of the inertia forces of rotating masses; at least two balancers respectively securely mounted on the countershaft at both ends respectively thereof for the balancing of the remainder of the inertia forces of reciprocating masses, and of the couple of inertia of the crankshaft about axes perpendicular to the crankshaft.

  12. Vibrations and stresses in layered anisotropic cylinders

    NASA Technical Reports Server (NTRS)

    Mulholland, G. P.; Gupta, B. P.

    1976-01-01

    An equation describing the radial displacement in a k layered anisotropic cylinder was obtained. The cylinders are initially unstressed but are subjected to either a time dependent normal stress or a displacement at the external boundaries of the laminate. The solution is obtained by utilizing the Vodicka orthogonalization technique. Numerical examples are given to illustrate the procedure.

  13. Separation tool for multipin electrical connectors

    NASA Technical Reports Server (NTRS)

    Smith, Larry D. (Inventor)

    1994-01-01

    A hydraulic tool for safely separating one multipin electrical connector from another is presented. The separation tool consists of a master cylinder which operates a pair of slave cylinders. Each slave cylinder has a corresponding operative shaft and an extraction tab. The slave cylinders are spaced apart from one another so that they may be positioned on either side of mated connector pairs of different sizes and so that their extraction tabs may be slid between the connectors. When the master cylinder's plunger is operated, its operation is hydraulically transmitted to the operative shafts of the slave cylinders which extend outward and, once pressed against a substrate, causes the slave cylinders and corresponding extractor tabs to move away and separate one connector from the other. A second preferred separation tool includes an additional pair of extractor tabs, one at the end of each operative shaft, so that the tool can be used to separate a mated connector pair hanging in free space.

  14. Multi-black-hole configurations on the cylinder

    SciTech Connect

    Dias, Oscar J. C.; Harmark, Troels; Obers, Niels A.; Myers, Robert C.

    2007-11-15

    We construct the metric of new multi-black-hole configurations on a d-dimensional cylinder R{sup d-1}xS{sup 1}, in the limit of small total mass (or equivalently in the limit of a large cylinder). These solutions are valid to first order in the total mass and describe configurations with several small black holes located at different points along the circle direction of the cylinder. We explain that a static configuration of black holes is required to be in equilibrium such that the external force on each black hole is zero, and we examine the resulting conditions. The first-order corrected thermodynamics of the solutions is obtained and a Newtonian interpretation of it is given. We then study the consequences of the multi-black-hole configurations for the phase structure of static Kaluza-Klein black holes and show that our new solutions imply continuous nonuniqueness in the phase diagram. The new multi-black-hole configurations raise the question of existence of new nonuniform black strings. Finally, a further analysis of the three-black-hole configuration suggests the possibility of a new class of static lumpy black holes in Kaluza-Klein space.

  15. Aeroacoustic Simulations of Tandem Cylinders with Subcritical Spacing

    NASA Technical Reports Server (NTRS)

    Lockard, David P.; Choudhari, Meelan M.; Khorrami, Mehdi R.; Neuhart, Dan H.; Hutcheson, Florence V.; Brooks, Thomas F.; Stead, Daniel J.

    2008-01-01

    Tandem cylinders are being studied because they model a variety of component level interactions of landing gear. The present effort is directed at the case of two identical cylinders with their centroids separated in the streamwise direction by 1.435 diameters. Experiments in the Basic Aerodynamic Research Tunnel and Quiet Flow Facility at NASA Langley Research Center have provided an extensive experimental database of the nearfield flow and radiated noise. The measurements were conducted at a Mach number of 0.1285 and Reynolds number of 1.66x10(exp 5) based on the cylinder diameter. A trip was used on the upstream cylinder to insure a fully turbulent flow separation and, hence, to simulate a major aspect of high Reynolds number flow. The parallel computational effort uses the three-dimensional Navier-Stokes solver CFL3D with a hybrid, zonal turbulence model that turns off the turbulence production term everywhere except in a narrow ring surrounding solid surfaces. The experiments exhibited an asymmetry in the surface pressure that was persistent despite attempts to eliminate it through small changes in the configuration. To model the asymmetry, the simulations were run with the cylinder configuration at a nonzero but small angle of attack. The computed results and experiments are in general agreement that vortex shedding for the spacing studied herein is weak relative to that observed at supercritical spacings. Although the shedding was subdued in the simulations, it was still more prominent than in the experiments. Overall, the simulation comparisons with measured near-field data and the radiated acoustics are reasonable, especially if one is concerned with capturing the trends relative to larger cylinder spacings. However, the flow details of the 1.435 diameter spacing have not been captured in full even though very fine grid computations have been performed. Some of the discrepancy may be associated with the simulation s inexact representation of the

  16. 9. General view of engine between cylinders with high pressure ...

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

    9. General view of engine between cylinders with high pressure cylinder on left and low pressure cylinder on right. - Carnegie Steel-Ohio Works, Steam Engines, 912 Salt Springs Road, Youngstown, Mahoning County, OH

  17. Motion of vortices outside a cylinder

    NASA Astrophysics Data System (ADS)

    Tulu, Serdar; Yilmaz, Oguz

    2010-12-01

    The problem of motion of the vortices around an oscillating cylinder in the presence of a uniform flow is considered. The Hamiltonian for vortex motion for the case with no uniform flow and stationary cylinder is constructed, reduced, and constant Hamiltonian (energy) curves are plotted when the system is shown to be integrable according to Liouville. By adding uniform flow to the system and by allowing the cylinder to vibrate, we model the natural vibration of the cylinder in the flow field, which has applications in ocean engineering involving tethers or pipelines in a flow field. We conclude that in the chaotic case forces on the cylinder may be considerably larger than those on the integrable case depending on the initial positions of vortices and that complex phenomena such as chaotic capture and escape occur when the initial positions lie in a certain region.

  18. Tests on Stiffened Circular Cylinders

    NASA Technical Reports Server (NTRS)

    Holt, Marshall

    1941-01-01

    Compressive tests were made of two series of stiffened circular cylindrical shells under axial load. All the shells were 16 inches in diameter by 24 inches in length and were made of aluminum-alloy sheet curved to the proper radius and welded with one longitudinal weld. The ratios of diameter to thickness of shell wall in the two series of specimens were 258 and 572. Strains were measured with Huggenberger tensometers at a number of gage lines on the stiffeners and shell. The results of these tests indicate that a spacing of circumferential stiffeners equal to 0.67 times the radius is too great to strengthen the shell wall appreciably. The results are not inclusive enough to show the optimum in stiffeners. Plain cylinders without stiffeners developed ultimate strengths approximately half as great as the buckling strengths computed by the equation resulting from the classical theory and slightly greater than those computed by Donnell's large deflection theory.

  19. Development of a small-scale power system with meso-scale vortex combustor and thermo-electric device

    NASA Astrophysics Data System (ADS)

    Shimokuri, D.; Hara, T.; Matsumoto, R.

    2015-10-01

    A small-scale vortex combustion power system has been developed using a thermo-electric device (TED). The system consisted of a heat medium, TED, and cooling plates. A vortex combustion chamber (7 mm inner diameter and 27 mm long) was fabricated inside the heat medium (40  ×  40  ×  20 mm and 52 g of duralumin). It was found that a stable propane/air flame could be established in the narrow 7 mm channel even for the large heat input conditions of 213 ~ 355 W. With a couple of TEDs, the maximum of 8.1 W (9.8 V  ×  0.83 A) could be successfully obtained for 355 W heat input, which corresponded to the energy conversion rate of 2.4%. The results of the gas and the combustor wall temperature measurements showed that the heat transfer from the burned gas to combustor wall was significantly enhanced by the vortex flow, which contributed to the relatively high efficiency energy conversion on the vortex combustion power system.

  20. Investigation of gain enhancement of electrically small antennas using double-negative, single-negative, and double-positive materials.

    PubMed

    Ghosh, B; Ghosh, S; Kakade, A B

    2008-08-01

    In this paper, it is shown that a double-negative or a mu-negative shell can be used to achieve a very high gain for an electrically small loop. It is also seen that together with the high gain, the metamaterial shell can be used to achieve a very uniform gain characteristic with respect to the shell dimensions. This is accomplished by a proper choice of the media parameters of the metamaterial shell and the region surrounding the antenna. This significantly eases the fabrication constraints and the close tolerances on the shell which was a major drawback towards the practical realization of the shell. Also, significant power gain can be obtained when the radiated power from the metamaterial shell is compared to the power radiated by a loop of the same radius as the outer radius of the shell. In addition, it is also found that a double-positive shell of the same dimensions as the metamaterial shell can be used to significantly increase the gain of the infinitesimal antenna. The power gain characteristics show distinct resonant peaks in this case. Excellent matching characteristics are observed corresponding to the radiated power gain.

  1. Techno-economic projections for advanced small solar thermal electric power plants to years 1990-2000

    NASA Technical Reports Server (NTRS)

    Fujita, T.; Manvi, R.; Roschke, E. J.; El-Gabalawi, N.; Herrera, G.; Kuo, T. J.; Chen, K. H.

    1979-01-01

    Advanced technologies applicable to solar thermal electric power systems in the 1990-200 time-frame are delineated for power applications that fulfill a wide spectrum of small power needs with primary emphasis on power ratings less than 10MWe. Projections of power system characteristics (energy and capital costs as a function of capacity factor) are made based on development of identified promising technologies and are used as the basis for comparing technology development options and combinations of these options to determine developmental directions offering potential for significant improvements. Stirling engines, Brayton/Rankine combined cycles and storage/transport concepts encompassing liquid metals, and reversible-reaction chemical systems are considered for two-axis tracking systems such as the central receiver or power tower concept and distributed parabolic dish receivers which can provide efficient low-cost solar energy collection while achieving high temperatures for efficient energy conversion. Pursuit of advanced technology across a broad front can result in post-1985 solar thermal systems having the potential of approaching the goal of competitiveness with conventional power systems.

  2. Direct Determination of a Small-Molecule Drug, Valproic Acid, by an Electrically-Detected Microcantilever Biosensor for Personalized Diagnostics

    PubMed Central

    Huang, Long-Sun; Gunawan, Christian; Yen, Yi-Kuang; Chang, Kai-Fung

    2015-01-01

    Direct, small-molecule determination of the antiepileptic drug, valproic acid, was investigated by a label-free, nanomechanical biosensor. Valproic acid has long been used as an antiepileptic medication, which is administered through therapeutic drug monitoring and has a narrow therapeutic dosage range of 50–100 μg·mL−1 in blood or serum. Unlike labeled and clinically-used measurement techniques, the label-free, electrical detection microcantilever biosensor can be miniaturized and simplified for use in portable or hand-held point-of-care platforms or personal diagnostic tools. A micromachined microcantilever sensor was packaged into the micro-channel of a fluidic system. The measurement of the antiepileptic drug, valproic acid, in phosphate-buffered saline and serum used a single free-standing, piezoresistive microcantilever biosensor in a thermally-controlled system. The measured surface stresses showed a profile over a concentration range of 50–500 μg·mL−1, which covered the clinically therapeutic range of 50–100 μg·mL−1. The estimated limit of detection (LOD) was calculated to be 45 μg·mL−1, and the binding affinity between the drug and the antibody was measured at around 90 ± 21 μg·mL−1. Lastly, the results of the proposed device showed a similar profile in valproic acid drug detection with those of the clinically-used fluorescence polarization immunoassay. PMID:25632826

  3. Experimental study on free convection of sodium in a long cylinder

    NASA Astrophysics Data System (ADS)

    Kolesnichenko, I. V.; Mamykin, A. D.; Pavlinov, A. M.; Pakholkov, V. V.; Rogozhkin, S. A.; Frick, P. G.; Khalilov, R. I.; Shepelev, S. F.

    2015-06-01

    The operation experience of sodium fast reactor shows that during design-basis validation of pipelines and equipment it is necessary to take into account the sodium free convection in the enclosures. The paper presents the results of experimental study of free convection of liquid sodium in a long thermo-insulated cylinder with the end heat supply and removal. The sodium-filled cylinder diameter is 168 mm, length is 850 mm. Three experiments for horizontal, inclined (at 45° to a vertical line) and vertical position of the cylinder were compared in detail. The Rayleigh number (based on cylinder diameter) is approximately same for three experiments and is equal to 5 × 106. The structure of large-scale and small-scale flows was analyzed. Nusselt number estimations being the intensity measure of heat transfer in case of free convection were obtained. A relationship between the flow structure and the Nusselt number is revealed.

  4. Calculation of Geometrical Parameters of Geokhod Transmission With Hydraulic Cylinders

    NASA Astrophysics Data System (ADS)

    Blaschuk, M. Yu; Dronov, A. A.; Ganovichev, S. S.

    2016-08-01

    Developed analytical expressions for determining parameters of transmission hydraulic cylinders' arrangement are considered, as well as the conditions for internal arrangement of a required number of hydraulic cylinders.

  5. Stability of the expansion-free charged cylinder

    SciTech Connect

    Sharif, M.; Bhatti, M. Zaeem Ul Haq E-mail: mzaeem.math@gmail.com

    2013-10-01

    We study the instability of cylindrically symmetric expansion-free anisotropic geometry in the presence of electromagnetic field. For smooth matching of the interior geometry with the exterior, junction conditions are formulated. The perturbation scheme is taken into account to describe the dynamical equation and categorize the Newtonian, post-Newtonian as well as post-post Newtonian regime. It is concluded that physical parameters, i.e., energy density, principal stresses of the fluid and electric charge control the stability of the cylinder.

  6. Operation Sun Beam, Shot Small Boy. Project Officer's report - Project 6. 9. Correlation of present and previous electric-field measurements

    SciTech Connect

    Reno; Fowles, H.M.

    1985-09-01

    On most previous nuclear detonations, signatures and quantitative measurements of the electric-field signals associated with the detonations was obtained at distances such that normal radiation field characteristics apply. On Small Boy, measurements were made from stations located much closer in, such as to be inside, on the boundary of and just outside the limits of the ionized sphere created by the nuclear burst. The electric-field characteristics in these regions were unknown. In the hope of providing continuity from the region of the unknown into the reasonably well-understood region of the radiation field, this project was requested to make the typical radiation-field type of measurement that had been made on previous detonations. This report covers the signature characteristics and quantitative measurements of the electric-field signal from Small Boy as seen from outside the immediate region of theoretical generating mechanism.

  7. Wave propagation in non-homogeneous magneto-electro-elastic hollow cylinders.

    PubMed

    Yu, Jiangong; Ma, Qiujuan; Su, Shan

    2008-12-01

    A dynamic solution is presented for the propagation of harmonic waves in imhomogeneous (functionally graded) magneto-electro-elastic hollow cylinders composed of piezoelectric BaTiO(3) and magnetostrictive CoFe(2)O(4). The materials properties are assumed to vary in the direction of the thickness according to a known variation law. The Legendre orthogonal polynomial series expansion approach is employed to determine the wave propagating characteristics in the hollow cylinders. The dispersion curves of the imhomogeneous piezoelectric-piezomagnetic hollow cylinder and the corresponding non-piezoelectric and non-piezomagnetic hollow cylinders are calculated to show the influence of the piezoelectricity and piezomagnetism. Electric potential and magnetic potential distributions are obtained to illustrate the different influences of the piezoelectricity and piezomagnetism and the different influences of the piezoelectric effect and piezomagnetic effect on longitudinal modes and torsional modes. For the radial polarizing piezoelectric-piezomagnetic hollow cylinder, the piezoelectric effect and piezomagnetic effect take mostly on the longitudinal mode. Finally, a hollow cylinder at different ratio of radius to thickness is calculated to show the influence of the ratio on the piezoelectric effect and piezomagnetic effect. PMID:18433821

  8. Gas cylinder release rate testing and analysis

    NASA Astrophysics Data System (ADS)

    Despres, Joseph; Sweeney, Joseph; Yedave, Sharad; Chambers, Barry

    2012-11-01

    There are varying cylinder technologies employed for the storage of gases, each resulting in a potentially different hazard level to the surroundings in the event of a gas release. Subatmospheric Gas delivery Systems Type I (SAGS I) store and deliver gases subatmospherically, while Subatmospheric Gas delivery Systems Type II (SAGS II) deliver gases subatmospherically, but store them at high pressure. Standard high pressure gas cylinders store and deliver their contents at high pressure. Due to the differences in these cylinder technologies, release rates in the event of a leak or internal component failure, can vary significantly. This paper details the experimental and theoretical results of different Arsine (AsH3) gas cylinder release scenarios. For the SAGS II experimental analysis, Fourier Transform Infrared Spectroscopy (FTIR) was used to determine the spatial concentration profiles when a surrogate gas, CF4, was released via a simulated leak within an ion implanter. Various SAGS I and SAGS II cylinder types and failure modes were tested. Additionally, theoretical analysis was performed to support an understanding of the different potential AsH3 leak rates. The results of this work show that the effects of a leak from the various cylinder types can be quite different, with the concentrations resulting from cylinders containing high pressure gas often being in excess of IDLH levels.

  9. TR-PIV measurement of the wake behind a grooved cylinder at low Reynolds number

    NASA Astrophysics Data System (ADS)

    Liu, Ying Zheng; Shi, Liu Liu; Yu, Jun

    2011-04-01

    A comparative study of the wakes behind cylinders with grooved and smooth surfaces was performed with a view to understand the wake characteristics associated with the adult Saguaro cacti. A low-speed recirculation water channel was established for the experiment; the Reynolds number, based on the free-stream velocity and cylinder diameter (D), was kept at ReD=1500. State-of-the-art time-resolved particle image velocimetry (TR-PIV) was employed to measure a total of 20 480 realizations of the wake field at a frame rate of 250 Hz, enabling a comprehensive view of the time- and phase-averaged wake pattern. In comparison to the wake behind the smooth cylinder, the length of the recirculation zone behind the grooved cylinder was extended by nearly 18.2%, yet the longitudinal velocity fluctuation intensity was considerably weakened. A global view of the peaked spectrum of the longitudinal velocity component revealed that the intermediate region for the grooved cylinder, which approximately corresponds to the transition region where the shear layer vortices interact, merge and shed before the formation of the Karman-like vortex street, was much wider than that for the smooth one. The unsteady events near St=0.3-0.4 were detected in the intermediate region behind the grooved cylinder, but no such events were found in the smooth cylinder system. Although the formation of the Karman-like vortex street was delayed by about 0.6D downstream for the grooved cylinder, no prominent difference in the vortex street region was found in the far wake for both cylinders. The Proper Orthogonal Decomposition (POD) method was used extensively to decompose the vector and swirling strength fields, which gave a close-up view of the vortices in the near wake. The first two POD modes of the swirling strength clarified the spatio-temporal characteristics of the shear layer vortices behind the grooved cylinder. The small-scale vortices superimposed on the shear layers behind the grooved cylinder

  10. Habitat Demonstration Unit (HDU) Vertical Cylinder Habitat

    NASA Technical Reports Server (NTRS)

    Howe, Alan; Kennedy, Kriss J.; Gill, Tracy R.; Tri, Terry O.; Toups, Larry; Howard, Robert I.; Spexarth, Gary R.; Cavanaugh, Stephen; Langford, William M.; Dorsey, John T.

    2014-01-01

    NASA's Constellation Architecture Team defined an outpost scenario optimized for intensive mobility that uses small, highly mobile pressurized rovers supported by portable habitat modules that can be carried between locations of interest on the lunar surface. A compact vertical cylinder characterizes the habitat concept, where the large diameter maximizes usable flat floor area optimized for a gravity environment and allows for efficient internal layout. The module was sized to fit into payload fairings for the Constellation Ares V launch vehicle, and optimized for surface transport carried by the All-Terrain Hex-Limbed Extra-Terrestrial Explorer (ATHLETE) mobility system. Launch and other loads are carried through the barrel to a top and bottom truss that interfaces with a structural support unit (SSU). The SSU contains self-leveling feet and docking interfaces for Tri-ATHLETE grasping and heavy lift. A pressurized module needed to be created that was appropriate for the lunar environment, could be easily relocated to new locations, and could be docked together in multiples for expanding pressurized volume in a lunar outpost. It was determined that horizontally oriented pressure vessels did not optimize floor area, which takes advantage of the gravity vector for full use. Hybrid hard-inflatable habitats added an unproven degree of complexity that may eventually be worked out. Other versions of vertically oriented pressure vessels were either too big, bulky, or did not optimize floor area. The purpose of the HDU vertical habitat module is to provide pressurized units that can be docked together in a modular way for lunar outpost pressurized volume expansion, and allow for other vehicles, rovers, and modules to be attached to the outpost to allow for IVA (intra-vehicular activity) transfer between them. The module is a vertically oriented cylinder with a large radius to allow for maximal floor area and use of volume. The modular, 5- m-diameter HDU vertical habitat

  11. Water-tunnel study of transition flow around circular cylinders

    NASA Technical Reports Server (NTRS)

    Almosnino, D.; Mcalister, K. W.

    1984-01-01

    The recently reported phenomenon of asymmetric flow separation from a circular cylinder in the critical Reynolds number regime has been confirmed in a water-tunnel experiment. For the first time, an attempt was made to visualize the wake of the cylinder during the transition from subcritical to critical flow and to correlate the visualizations with lift and drag measurements. The occurrence of a dominant asymmetric-flow state was quite repeatable, both when increasing and decreasing the Reynolds number, resulting in a mean lift coefficient of C sub L approx 1.2 and a shift in the angle of the wake by about 12 deg. A distinctive step change in the drag and shedding frequency was also found to occur. A hysteresis was confirmed to exist in this region as the Reynolds number was cycled over the transition range. Both boundaries of the asymmetry appear to be supercritical bifurcations in the flow. The asymmetry was normally steady in the mean; however, there were instances when the direction of the asymmetry reversed and remained so for the duration of the Reynolds number sweep through this transition region. A second asymmetry was observed at a higher Reynolds number; however, the mean lift coefficient was much lower, and the direction of the asymmetry was not observed to reverse. Introducing a small local disturbance into the boundary layer was found to prevent the critical asymmetry from developing along the entire span of the cylinder.

  12. High-Frequency Normal Mode Propagation in Aluminum Cylinders

    USGS Publications Warehouse

    Lee, Myung W.; Waite, William F.

    2009-01-01

    Acoustic measurements made using compressional-wave (P-wave) and shear-wave (S-wave) transducers in aluminum cylinders reveal waveform features with high amplitudes and with velocities that depend on the feature's dominant frequency. In a given waveform, high-frequency features generally arrive earlier than low-frequency features, typical for normal mode propagation. To analyze these waveforms, the elastic equation is solved in a cylindrical coordinate system for the high-frequency case in which the acoustic wavelength is small compared to the cylinder geometry, and the surrounding medium is air. Dispersive P- and S-wave normal mode propagations are predicted to exist, but owing to complex interference patterns inside a cylinder, the phase and group velocities are not smooth functions of frequency. To assess the normal mode group velocities and relative amplitudes, approximate dispersion relations are derived using Bessel functions. The utility of the normal mode theory and approximations from a theoretical and experimental standpoint are demonstrated by showing how the sequence of P- and S-wave normal mode arrivals can vary between samples of different size, and how fundamental normal modes can be mistaken for the faster, but significantly smaller amplitude, P- and S-body waves from which P- and S-wave speeds are calculated.

  13. The stress development during filament winding of thick cylinders

    NASA Astrophysics Data System (ADS)

    Hahn, H. T.; Lee, S. S.

    1992-08-01

    The stress development during filament winding of thick composite cylinders has been studied using dry glass fiber tows. The thicknesses of the wound cylinders were more than 38 mm while the aluminum mandrel used had an outside diameter of 58 mm. Circumferential winding was used and the winding tension was varied between 4 and 23 N. The radial pressure measured at the mandrel surface using foil gages increased over the first 6 layers or so of winding, and then stayed constant or even decreased slightly with subsequent winding. Predictions based on elastic analyses were fitted to the data by varying the effective radial modulus. The resulting values of the radial modulus were much less than the circumferential modulus, the latter being more than ten-thousand times greater than the former. Such high anisotropy was responsible for the asymptotic increase of the mandrel pressure with winding. The calculated circumferential stress in the fibers was compressive throughout most of the inner part of the wound cylinder however, its magnitude was rather small. A higher winding tension resulted in a better compaction, and therefore, a smaller effective layer thickness, a higher radial modulus, and higher internal stresses. Under the winding conditions studied in the present work, fiber buckling due to the development of compressive circumferential stress does not appear possible.

  14. Scattering matrix of infrared radiation by ice finite circular cylinders.

    PubMed

    Xu, Lisheng; Ding, Jilie; Cheng, Andrew Y S

    2002-04-20

    Scattering matrix characteristics of polydisperse, randomly oriented, small ice crystals modeled by finite circular cylinders with various ratios of the length to diameter (L/D) ratio are calculated by use of the exact T-matrix approach, with emphasis on the thermal infrared spectral region that extends from the atmospheric short-wave IR window to the far-IR wavelengths to as large as 30 microm. The observed ice crystal size distribution and the well-known power-law distribution are considered. The results of the extensive calculations show that the characteristics of scattering matrix elements of small ice circular cylinders depend strongly on wavelengths and refractive indices, particle size distributions, and the L/D ratios. The applicability of the power-law distribution and particle shapes for light scattering calculations for small ice crystals is discussed. The effects of the effective variance of size distribution on light scattering characteristics are addressed. It seems from the behavior of scattering matrix elements of small ice crystals that the combination of 25 and 3.979 microm has some advantages and potential applications for remote sensing of cirrus and other ice clouds.

  15. Thermal and catalytic pyrolysis of a mixture of plastics from small waste electrical and electronic equipment (WEEE).

    PubMed

    Santella, Chiara; Cafiero, Lorenzo; De Angelis, Doina; La Marca, Floriana; Tuffi, Riccardo; Vecchio Ciprioti, Stefano

    2016-08-01

    Pyrolysis seems a promising route for recycling of heterogeneous, contaminated and additives containing plastics from waste electrical and electronic equipment (WEEE). This study deals with the thermal and catalytic pyrolysis of a synthetic mixture containing real waste plastics, representative of polymers contained in small WEEE. Two zeolite-based catalysts were used at 400°C: HUSY and HZSM-5 with a high silica content, while three different temperatures were adopted for the thermal cracking: 400, 600 and 800°C. The mass balance showed that the oil produced by pyrolysis is always the main product regardless the process conditions selected, with yields ranging from 83% to 93%. A higher yield was obtained when pyrolysis was carried out with HZSM-5 at 400°C and without catalysts, but at 600 and 800°C. Formation of a significant amount of solid residue (about 13%) is observed using HUSY. The oily liquid product of pyrolysis, analysed by GC-MS and GC-FID, as well as by elemental analysis and for energy content, appeared lighter, less viscous and with a higher concentration of monoaromatics under catalytic condition, if compared to the liquid product derived from thermal degradation at the same temperature. HZSM-5 led to the production of a high yield of styrene (17.5%), while HUSY favoured the formation of ethylbenzene (15%). Energy released by combustion of the oil was around 39MJ/kg, thus suggesting the possibility to exploit it as a fuel, if the recovery of chemical compounds could not be realised. Elemental and proximate analysis of char and GC-TCD analysis of the gas were also performed. Finally, it was estimated to what extent these two products, showing a relevant ability to release energy, could fulfil the energy demand requested in pyrolysis.

  16. Thermal and catalytic pyrolysis of a mixture of plastics from small waste electrical and electronic equipment (WEEE).

    PubMed

    Santella, Chiara; Cafiero, Lorenzo; De Angelis, Doina; La Marca, Floriana; Tuffi, Riccardo; Vecchio Ciprioti, Stefano

    2016-08-01

    Pyrolysis seems a promising route for recycling of heterogeneous, contaminated and additives containing plastics from waste electrical and electronic equipment (WEEE). This study deals with the thermal and catalytic pyrolysis of a synthetic mixture containing real waste plastics, representative of polymers contained in small WEEE. Two zeolite-based catalysts were used at 400°C: HUSY and HZSM-5 with a high silica content, while three different temperatures were adopted for the thermal cracking: 400, 600 and 800°C. The mass balance showed that the oil produced by pyrolysis is always the main product regardless the process conditions selected, with yields ranging from 83% to 93%. A higher yield was obtained when pyrolysis was carried out with HZSM-5 at 400°C and without catalysts, but at 600 and 800°C. Formation of a significant amount of solid residue (about 13%) is observed using HUSY. The oily liquid product of pyrolysis, analysed by GC-MS and GC-FID, as well as by elemental analysis and for energy content, appeared lighter, less viscous and with a higher concentration of monoaromatics under catalytic condition, if compared to the liquid product derived from thermal degradation at the same temperature. HZSM-5 led to the production of a high yield of styrene (17.5%), while HUSY favoured the formation of ethylbenzene (15%). Energy released by combustion of the oil was around 39MJ/kg, thus suggesting the possibility to exploit it as a fuel, if the recovery of chemical compounds could not be realised. Elemental and proximate analysis of char and GC-TCD analysis of the gas were also performed. Finally, it was estimated to what extent these two products, showing a relevant ability to release energy, could fulfil the energy demand requested in pyrolysis. PMID:27184448

  17. Multi-cylinder hot gas engine

    DOEpatents

    Corey, John A.

    1985-01-01

    A multi-cylinder hot gas engine having an equal angle, V-shaped engine block in which two banks of parallel, equal length, equally sized cylinders are formed together with annular regenerator/cooler units surrounding each cylinder, and wherein the pistons are connected to a single crankshaft. The hot gas engine further includes an annular heater head disposed around a central circular combustor volume having a new balanced-flow hot-working-fluid manifold assembly that provides optimum balanced flow of the working fluid through the heater head working fluid passageways which are connected between each of the cylinders and their respective associated annular regenerator units. This balanced flow provides even heater head temperatures and, therefore, maximum average working fluid temperature for best operating efficiency with the use of a single crankshaft V-shaped engine block.

  18. Monitoring of corrosion in ORGDP cylinder yards

    SciTech Connect

    Henson, H.M.; Barlow, C.R.; Frazier, J.L.; Ziehlke, K.T.

    1989-01-01

    Uranium hexafluoride (UF/sub 6/) throughout the nuclear fuel cycle is handled and stored in cylinders which are designed, manufactured, and maintained in accordance with the ASME Boiler and Pressure Vessel Code for unfired pressure vessels (Section VIII). There are presently more than 40,000 of these cylinders within the DOE Oak Ridge Operations complex currently used for the storage of isotopically depleted material (process tailings). These tails cylinders, in 10- and 14-ton sizes, are 48 inches in diameter and were originally constructed of steel ASTM A285, then since 1978 of steel ASTM A516. The corrosion and monitoring of corrosion of the cylinders is discussed. 8 refs., 6 figs.

  19. Experimental Investigations of Flow past Spinning Cylinders

    NASA Astrophysics Data System (ADS)

    Carlucci, Pasquale; Buckley, Liam; Mehmedagic, Igbal; Carlucci, Donald; Thangam, Siva

    2015-11-01

    Experimental investigations of flow past spinning cylinders is presented in the context of their application and relevance to flow past projectiles. A subsonic wind tunnel is used to perform experiments on flow past spinning cylinders that are sting-mounted and oriented such that their axis of rotation is aligned with the mean flow. The experiments cover a Reynolds number range of up to 300000 and rotation numbers of up to 2 (based on cylinder diameter). The experimental validation of the tunnel characteristics and the benchmarking of the flow field in the tunnel are described. The experimental results for spinning cylinders with both rear-mounted and fore-mounted stings are presented along with available computational and experimental findings. This work was funded in part by U. S. Army ARDEC.

  20. Investigations of Flow past Spinning Cylinders

    NASA Astrophysics Data System (ADS)

    Mehmedagic, Igbal; Carlucci, Pasquale; Buckley, Liam; Carlucci, Donald; Aljallis, Elias; Thangam, Siva

    2013-11-01

    A subsonic wind tunnel is used to perform experiments on flow past spinning cylinders. The blunt cylinders are sting-mounted and oriented such that their axis of rotation is aligned with the mean flow. The experiments cover a Reynolds number range of up to 300000 and rotation numbers of up to 1.2 (based on cylinder diameter). The results for spinning cylinders with both rear-mounted and fore-mounted stings are presented. Computations are performed using a two-equation anisotropic turbulence model that is based on proper representation of the energy spectrum to capture rotation and curvature. The model performance is validated with benchmark experimental flows and implemented for analyzing the flow configuration used in the experimental study. Funded in part by U. S. Army, ARDEC.

  1. Dynamic Fracture Simulations of Explosively Loaded Cylinders

    SciTech Connect

    Arthur, Carly W.; Goto, D. M.

    2015-11-30

    This report documents the modeling results of high explosive experiments investigating dynamic fracture of steel (AerMet® 100 alloy) cylinders. The experiments were conducted at Lawrence Livermore National Laboratory (LLNL) during 2007 to 2008 [10]. A principal objective of this study was to gain an understanding of dynamic material failure through the analysis of hydrodynamic computer code simulations. Two-dimensional and three-dimensional computational cylinder models were analyzed using the ALE3D multi-physics computer code.

  2. Patterns of electronegative ions past a cylinder

    NASA Astrophysics Data System (ADS)

    Xiang, Xiaofeng; Wu, Xing; Guo, Li; Ma, Xiaoxun; Xia, Yashen

    2012-10-01

    The behavior of the wake of an electronegative gas flow past either a glass or a magnetic circular cylinder was observed using the smoke wire flow visualization technique. Converging or chaotic vortices for the electronegative flow of air and oxygen past a magnetic cylinder were seen in shedding vortices, especially at higher concentrations of electronegative molecules, eventually leading to the disappearance of a Kármán vortex, possibly due to the effect of ‘interactive solenoids’.

  3. Aerodynamic characteristics of a square cylinder with a rod in a staggered arrangement

    NASA Astrophysics Data System (ADS)

    Zhang, P. F.; Wang, J. J.; Lu, S. F.; Mi, J.

    2005-04-01

    The aerodynamic characteristics of a square cylinder with an upstream rod in a staggered arrangement were examined. The pressure measurement was conducted in a wind tunnel at a Reynolds number of ReD=82,000 (based on the width of the square cylinder) and the flow visualization was carried out in a water tunnel with the hydrogen bubble technique at ReD=5,200. When the rod and the square cylinder were in tandem, the reduction of drag was mainly caused by the increase of the rear suction pressure. When the staggered angle was introduced, the shield and disturbance effect of the rod on the square cylinder diminished, which results in the increase of the cylinder drag. The side force induced by the staggered angle is small (the maximum value is 20% of the drag of the isolate square cylinder). There were six different flow modes with various staggered angles and spacing ratios, and the corresponding flow patterns are presented in present paper.

  4. Stacked pneumatic cylinders automate conveyor belt operations

    SciTech Connect

    Thornton, G.

    1982-11-01

    Shows how clusters of remotely controlled pneumatic cylinders swing a hinged conveyor belt to 4 preselected vertical positions. Using a manual method to move the conveyor meant that the operator had to use a hand winch, sheaves, drums, and winch cable. There was a need to develop a simple, effective, and remotely controlled system which would perform 2 functions: eliminate the need for stopping the conveyor to reset the hinged belt, and not require the operator to leave the master control console. Using the developed system, the operator need only turn on the appropriate switching valves from the master console. Each pneumatic cylinder is actuated in sequence, on the retraction stroke only, through the elevating positions. To lower the conveyor belt, the head end of each cylinder is exhausted; the weight of the belt extends the cylinders, lowering the belt by gravity. Cylinder exhaust ports in the power valves are fitted with adjustable flow control valves to regulate cylinder speed; common exhaust ports in the interconnected manifolds are fitted with air silencers.

  5. The quest to be "modern": The adoption of electric light, heat, and power technology in small-town America, 1883-1929

    NASA Astrophysics Data System (ADS)

    Hellrigel, Mary Ann

    This dissertation is a social, business, and technological history of electrification in the United States. It examines the origins of the electric utility industry, the development of light, heat and power technology, the marketing of electric service, and the adoption of electricity and domestic appliances in the late nineteenth and early twentieth centuries in two communities: Harrisburg and West Chester, Pennsylvania. Beginning in the 1880s, manufactured gas and electric utilities waged an intense and lengthy battle for the urban energy marketplace. Many villages, small towns and big cities had multiple gas and electric companies, driving technological change as they worked to increase reliability, lower costs, and improve lamps, lighting fixtures, and appliances. Producers as well as consumers grappled with these new sources of energy, looking for profitable and practical ways to incorporate them into everyday life. Gas and utility executives, locked in head-to-head competition, realized that marketing their invisible product was an uncertain process. Utilities redefined the concepts of "tradition" and "modernity" to attract investors and offer appliances and installation in addition to selling energy. Upper and middle class households seeking a modern comfortable home could use gas or electricity (and often both), while working classes made do with kerosene, coal and wood. Mixed technologies, based on consumer preference, access, product availability, price, and service greatly influenced the creation of "modern" America. Initially, Pennsylvania law mandated local energy systems-electricity and gas had to be consumed within the same town. Only in the early twentieth century were these laws amended to permit inter-connections, allowing merger and consolidation of utilities to serve a wider geographic area. By the 1910s, law, technology, and capital made it possible to abandon local central stations. In only a few decades, the industry shifted from locally

  6. Externally pressurized porous cylinder for multiple surface aerosol generation and method of generation

    DOEpatents

    Apel, C.T.; Layman, L.R.; Gallimore, D.L.

    1988-05-10

    A nebulizer is described for generating aerosol having small droplet sizes and high efficiency at low sample introduction rates. The nebulizer has a cylindrical gas permeable active surface. A sleeve is disposed around the cylinder and gas is provided from the sleeve to the interior of the cylinder formed by the active surface. In operation, a liquid is provided to the inside of the gas permeable surface. The gas contacts the wetted surface and forms small bubbles which burst to form an aerosol. Those bubbles which are large are carried by momentum to another part of the cylinder where they are renebulized. This process continues until the entire sample is nebulized into aerosol sized droplets. 2 figs.

  7. Aspects of uranium chemistry pertaining to UF{sub 6} cylinder handling

    SciTech Connect

    Ritter, R.L.; Barber, E.J.

    1991-12-31

    Under normal conditions, the bulk of UF{sub 6} in storage cylinders will be in the solid state with an overpressure of gaseous UF{sub 6} well below one atmosphere. Corrosion of the interior of the cylinder will be very slow, with formation of a small amount of reduced fluoride, probably U{sub 2}F{sub 9}. The UO{sub 3}-HF-H{sub 2}O phase diagram indicates that reaction of any inleaking water vapor with the solid UF{sub 6} will generate the solid material [H{sub 3}O]{sub 2}(U(OH){sub 4}F{sub 4}) in equilibrium with an aqueous HF solution containing only small amounts of uranium. The corrosion of the steel cylinder by these materials may be enhanced over that observed with gaseous anhydrous UF{sub 6}.

  8. Where Millimeter Wave Spectra are Sensitive to Small Electric Fields: High Rydberg States of Xenon and Their Hyperfine Structures

    NASA Astrophysics Data System (ADS)

    Schäfer, Martin; Raunhardt, Matthias; Merkt, Frédéric

    2009-06-01

    In the range 0-45 cm^{-1} below the ionization limit, the separation between adjacent electronic states (Rydberg states with principal quantum number n>50) of atoms and molecules is smaller than 2 cm^{-1}. In order to resolve the fine or hyperfine structure of these states, it is necessary to combine high-resolution vacuum ultraviolet (VUV) laser radiation, which is required to access the Rydberg states from the ground state, with millimeter wave radiation. Such double-resonance experiments have been used to study the hyperfine structure of high Rydberg states of ^{83}Kr, H_2 or D_2. Millimeter wave transitions (240-350 GHz) between nℓ (52≤ n≤64, ℓ≤3) Rydberg states of different xenon isotopes were detected by pulsed field ionization followed by mass-selective detection of the cations. Because of the high polarizability of high-n Rydberg states (∝ n^7, ˜10^4 MHz cm^{2} V^{-2} for n≈ 50), it is necessary to reduce the electric stray fields to values of the order of mV/cm (or less) in order to minimize the (quadratic) Stark shift of the millimeter wave transitions. Some p and d Rydberg states of Xe are nearly degenerate and efficiently mixed by small stray fields, making it possible to observe transitions forbidden by the Δℓ=±1 selection rule or transitions exhibiting a linear Stark effect, which is typical for the degenerate high-ℓ Rydberg states. Multichannel quantum defect theory (MQDT) was used to analyze the millimeter wave data and to determine the hyperfine structures of the ^2P_{3/2} ground electronic states of ^{129}Xe^+ and ^{131}Xe^+. C. Fabre, P. Goy, S. Haroche, J. Phys. B: Atom. Mol. Phys. 10, L183-189 (1977). F. Merkt, A. Osterwalder, Int. Rev. Phys. Chem. 21, 385-403 (2002). M. Schäfer, M. Andrist, H. Schmutz, F. Lewen, G. Winnewisser, F. Merkt, J. Phys. B: At. Mol. Opt. Phys. 39, 831-845 (2006) M. Schäfer, F. Merkt, Phys. Rev. A, 74, 062506 (2006). A. Osterwalder, A. Wüest, F. Merkt, Ch. Jungen, J. Chem. Phys., 121, 11810

  9. Development of a new generation of small scale biomass-fueled electric generating power plants. Technical report, 21--24 August 1995

    SciTech Connect

    Criag, J.D.; Purvis, C.R.

    1995-08-01

    There exists a need by a large worldwide market for greatly improved small scale (1 to 20 MWe per unit) biomass-fueled power plants. These power plants will significantly increase the efficiency of generating electric power from wood and bagasse as well as convert non-traditional fuel sources such as rice bulls, animal manure, cotton gin trash, straws, and grasses to electricity. Advancing the technology of biomass-fueled power plants will greatly expand the use of this environmentally friendly sustainable 24 hr-per-day source of electrical power for industry and communities worldwide. This paper briefly describes the status of a biomass-fueled power plant under development by Cratech, Inc.

  10. Dynamic Friction Performance of a Pneumatic Cylinder with Al2O3 Film on Cylinder Surface.

    PubMed

    Chang, Ho; Lan, Chou-Wei; Wang, Hao-Xian

    2015-11-01

    A friction force system is proposed for accurately measuring friction force and motion properties produced by reciprocating motion of piston in a pneumatic cylinder. In this study, the proposed system is used to measure the effects of lubricating greases of different viscosities on the friction properties of pneumatic cylinder, and improvement of stick-slip motion for the cylinder bore by anodizing processes. A servo motor-driven ball screw is used to drive the pneumatic cylinder to be tested and to measure the change in friction force of the pneumatic cylinder. Experimental results show, that under similar test conditions, the lubricating grease with viscosity VG100 is best suited for measuring reciprocating motion of the piston of pneumatic cylinder. The wear experiment showed that, in the Al2O3 film obtained at a preset voltage 40 V in the anodic process, the friction coefficient and hardness decreased by 55% and increased by 274% respectively, thus achieving a good tribology and wear resistance. Additionally, the amplitude variation in the friction force of the pneumatic cylinder wall that received the anodizing treatment was substantially reduced. Additionally, the stick-slip motion of the pneumatic cylinder during low-speed motion was substantially improved. PMID:26726680

  11. Scattering by an infinite homogenous anisotropic elliptic cylinder in terms of Mathieu functions and Fourier series.

    PubMed

    Mao, Shi-Chun; Wu, Zhen-Sen

    2008-12-01

    An exact solution to the two-dimensional scattering properties of an anisotropic elliptic cylinder for transverse electric polarization is presented. The internal field in an anisotropic elliptic cylinder is expressed as integral representations of Mathieu functions and Fourier series. The coefficients of the series expansion are obtained by imposing boundary conditions on the anisotropic-free-space interface. A matrix is developed to solve the nonorthogonality properties of Mathieu functions at the interface between two different media. Numerical results are given for the bistatic radar cross section and the amplitude of the total magnetic field along the x and y axes. The result is in agreement with that available as expected when an elliptic cylinder degenerates to a circular one.

  12. Status Report on the Passive Neutron Enrichment Meter (PNEM) for UF6 Cylinder Assay

    SciTech Connect

    Miller, Karen A.; Swinhoe, Martyn T.; Menlove, Howard O.; Marlow, Johnna B.

    2012-05-02

    The Passive Neutron Enrichment Meter (PNEM) is a nondestructive assay (NDA) system being developed at Los Alamos National Laboratory (LANL). It was designed to determine {sup 235}U mass and enrichment of uranium hexafluoride (UF{sub 6}) in product, feed, and tails cylinders (i.e., 30B and 48Y cylinders). These cylinders are found in the nuclear fuel cycle at uranium conversion, enrichment, and fuel fabrication facilities. The PNEM is a {sup 3}He-based neutron detection system that consists of two briefcase-sized detector pods. A photograph of the system during characterization at LANL is shown in Fig. 1. Several signatures are currently being studied to determine the most effective measurement and data reduction technique for unfolding {sup 235}U mass and enrichment. The system collects total neutron and coincidence data for both bare and cadmium-covered detector pods. The measurement concept grew out of the success of the Uranium Cylinder Assay System (UCAS), which is an operator system at Rokkasho Enrichment Plant (REP) that uses total neutron counting to determine {sup 235}U mass in UF{sub 6} cylinders. The PNEM system was designed with higher efficiency than the UCAS in order to add coincidence counting functionality for the enrichment determination. A photograph of the UCAS with a 48Y cylinder at REP is shown in Fig. 2, and the calibration measurement data for 30B product and 48Y feed and tails cylinders is shown in Fig. 3. The data was collected in a low-background environment, meaning there is very little scatter in the data. The PNEM measurement concept was first presented at the 2010 Institute of Nuclear Materials Management (INMM) Annual Meeting. The physics design and uncertainty analysis were presented at the 2010 International Atomic Energy Agency (IAEA) Safeguards Symposium, and the mechanical and electrical designs and characterization measurements were published in the ESARDA Bulletin in 2011.

  13. Corrosion monitoring in the UF{sub 6} cylinder yards at the Oak Ridge K-25 Site: FY 1994 report

    SciTech Connect

    Rao, M.; Adamski, R.; Broders, J.; Ellis, A.; Freels, D.; Kelley, D.; Phillips, B.

    1994-10-01

    Depleted uranium hexafluoride (UF{sub 6}) at the U.S. Department of Energy`s K-25 Site at Oak Ridge, Tennessee, has been stored in large steel cylinders that have undergone significant atmospheric corrosion damage over the last 35 years. A detailed experimental program to characterize the corrosion damage was initiated in 1992. Large amounts of corrosion scale and deep pits are found to cover UF{sub 6} cylinder surfaces. Ultrasonic wall thickness measurements have shown uniform corrosion losses up to 20 mils (0.5 mm) and pits up to 100 mils (2.5 mm) deep. Electrical resistance corrosion probes, TOW sensors, and thermocouples have been attached to cylinder bodies. Atmospheric conditions are monitored using rain gauges, relative humidity sensors, and thermocouples. Long-term (16-year) data are being obtained from mild steel corrosion coupons on test racks as well as attached directly to cylinder surfaces. Corrosion rates have been found to be intimately related to the times-of-wetness, both tending to be higher on cylinder tops due to apparent sheltering effects. Data from the various tests are compared, discrepancies are discussed, and a pattern of cylinder corrosion as a function of cylinder position and location is described.

  14. Analysis of condensation on a horizontal cylinder with unknown wall temperature and comparison with the Nusselt model of film condensation

    NASA Technical Reports Server (NTRS)

    Bahrami, Parviz A.

    1996-01-01

    Theoretical analysis and numerical computations are performed to set forth a new model of film condensation on a horizontal cylinder. The model is more general than the well-known Nusselt model of film condensation and is designed to encompass all essential features of the Nusselt model. It is shown that a single parameter, constructed explicitly and without specification of the cylinder wall temperature, determines the degree of departure from the Nusselt model, which assumes a known and uniform wall temperature. It is also known that the Nusselt model is reached for very small, as well as very large, values of this parameter. In both limiting cases the cylinder wall temperature assumes a uniform distribution and the Nusselt model is approached. The maximum deviations between the two models is rather small for cases which are representative of cylinder dimensions, materials and conditions encountered in practice.

  15. Vision-guided gripping of a cylinder

    NASA Technical Reports Server (NTRS)

    Nicewarner, Keith E.; Kelley, Robert B.

    1991-01-01

    The motivation for vision-guided servoing is taken from tasks in automated or telerobotic space assembly and construction. Vision-guided servoing requires the ability to perform rapid pose estimates and provide predictive feature tracking. Monocular information from a gripper-mounted camera is used to servo the gripper to grasp a cylinder. The procedure is divided into recognition and servo phases. The recognition stage verifies the presence of a cylinder in the camera field of view. Then an initial pose estimate is computed and uncluttered scan regions are selected. The servo phase processes only the selected scan regions of the image. Given the knowledge, from the recognition phase, that there is a cylinder in the image and knowing the radius of the cylinder, 4 of the 6 pose parameters can be estimated with minimal computation. The relative motion of the cylinder is obtained by using the current pose and prior pose estimates. The motion information is then used to generate a predictive feature-based trajectory for the path of the gripper.

  16. A jumping cylinder on an inclined plane

    NASA Astrophysics Data System (ADS)

    Gómez, R. W.; Hernández-Gómez, J. J.; Marquina, V.

    2012-09-01

    The problem of a cylinder of mass m and radius r, with its centre of mass out of the cylinder’s axis, rolling on an inclined plane that makes an angle α with respect to the horizontal, is analysed. The equation of motion is partially solved to obtain the site where the cylinder loses contact with the inclined plane (jumps). Several simplifications are made: the analysed system consists of an homogeneous disc with a one-dimensional straight line mass parallel to the disc axis at a distance y < r of the centre of the cylinder. To compare our results with experimental data, we use a styrofoam cylinder to which a long brass rod is embedded parallel to the disc axis at a distance y < r from it, so the centre of mass lies at a distance d from the centre of the cylinder. Then the disc rolls without slipping on a long wooden ramp inclined at 15°, 30° and 45° with respect to the horizontal. To determine the jumping site, the movements are recorded with a high-speed video camera (Casio EX ZR100) at 240 and 480 frames per second. The experimental results agree well with the theoretical predictions.

  17. A jumping cylinder in an incline

    NASA Astrophysics Data System (ADS)

    Gomez, Raul W.; Hernandez, Jorge; Marquina, Vivianne

    2012-02-01

    The problem of a cylinder of mass m and radius r, with its center of mass out of the cylinder axis, rolling in an incline that makes an angle α respect to the horizontal is analyzed. The equation of motion is solved to obtain the site where the cylinder loses contact with the incline (jumps). Several simplifications are made: the analyzed system consists of an homogeneous disc with a one dimensional straight line of mass parallel to the disc axis at a distance d < r of the center of the cylinder. To compare our results with experimental data, we use a Styrofoam cylinder of radius r = 10.0 ± 0.05 cm, high h = 5.55 ± 0.05 cm and a mass m1 = 24.45 ± 0.05 g, to which a 9.50 ± 0.01 mm diameter and 5.10 ± 0.001 cm long brass road of mass m2 = 30.75 ± 0.05 g was imbibed parallel to the disc axis at a distance of 5.40 ± 0.05 cm from it. Then the disc rolls on a 3.20 m long wooden ramp inclined at 30 and 45 respect to the horizontal. To determine the jumping site, the movements were recorded with a high-speed video camera (Casio EX ZR100) at 400 frames per second. The experimental results agree well with the theoretical predictions.

  18. Balancer structure for three-cylinder engines

    SciTech Connect

    Suzuki, T.

    1986-01-21

    This patent describes a balancer structure for a three-cylinder in-line engine. The in-line engine is indicated in the patent as having a crankshaft having crank arms configured at angles of 120/sup 0/ with respect to each other and operatively connected to a piston assembly within each of the cylinders. This crankshaft and assembly, which serves as a balancer structure as one of its applications, is further characterized in the patent as consisting of a number of component parts. The first component described is a single countershaft adjacent and parallel to the crankshaft. It is specified in the patent that this countershaft must rotate at the same speed as the crankshaft but in an opposite direction in order to fulfill its role in the balancer structure. The patent also details an element of the balancer structure which consists of a means utilizing counterweights mounted on the crankshaft at the first and third cylinder positions. These weights are indicated as partially balancing the inertia forces of reciprocating masses and the entire inertia forces of rotating masses present in the described engine. The required position of these counterweights is indicated as being a location more than 90/sup 0/ from the crank arm for the corresponding cylinder and perpendicular to the second cylinder crank arm. The last component described consists of two balancers mounted on both ends of the countershaft which balance the remainder of the inertia forces of reciprocating masses and the inertia of the crankshaft about axes perpendicular to itself.

  19. Balancer structure for three-cylinder engines

    SciTech Connect

    Suzuki, T.

    1986-02-11

    This patent describes a balancer structure for a three-cylinder in-line engine having aligned three cylinders, a crankshaft having crank arms disposed at angles of 120/sup 0/ with respect to each other and operatively connected to the cylinders, respectively. This structure consists of: 1.) a single countershaft adjacent and parallel to and rotated at the same speed as the crankshaft but in the opposite direction; 2.) a counterweight is securely mounted on the crankshaft only at positions corresponding to the first and third cylinders for balancing a part of inertia force of reciprocating mases and the entire inertia force of rotating masses; 3.) at least one second counterweight securely mounted on the crankshaft substantially opposite to the crank arm corresponding to the second cylinder for balancing another part of the inertia force of the reciprocating masses; 4.) at least two balancers securely mounted on the countershaft at both ends for the balancing of the remainder of the inertia force of the reciprocating masses and a couple of inertia of the crankshaft about an axis perpendicular to the crankshaft.

  20. UF{sub 6} cylinder fire test

    SciTech Connect

    Park, S.H.

    1991-12-31

    With the increasing number of nuclear reactors for power generation, there is a comparable increase in the amount of UF{sub 6} being transported. Likewise, the probability of having an accident involving UF{sub 6}-filled cylinders also increases. Accident scenarios which have been difficult to assess are those involving a filled UF{sub 6} cylinder subjected to fire. A study is underway at the Oak Ridge K-25 Site, as part of the US DOE Enrichment Program, to provide empirical data and a computer model that can be used to evaluate various cylinder-in-fire scenarios. It is expected that the results will provide information leading to better handling of possible fire accidents as well as show whether changes should be made to provide different physical protection during shipment. The computer model being developed will be capable of predicting the rupture of various cylinder sizes and designs as well as the amount of UF{sub 6}, its distribution in the cylinder, and the conditions of the fire.

  1. Experimental Evaluation of a Method for Turbocharging Four-Stroke, Single Cylinder, Internal Combustion Engines

    NASA Astrophysics Data System (ADS)

    Buchman, Michael; Winter, Amos

    2015-11-01

    Turbocharging an engine increases specific power, improves fuel economy, reduces emissions, and lowers cost compared to a naturally aspirated engine of the same power output. These advantages make turbocharging commonplace for multi-cylinder engines. Single cylinder engineers are not commonly turbocharged due to the phase lag between the exhaust stroke, which powers the turbocharger, and the intake stroke, when air is pumped into the engine. Our proposed method of turbocharging single cylinder engines is to add an ``air capacitor'' to the intake manifold, an additional volume that acts as a buffer to store compressed air between the exhaust and intake strokes, and smooth out the pressure pulses from the turbocharger. This talk presents experimental results from a single cylinder, turbocharged diesel engine fit with various sized air capacitors. Power output from the engine was measured using a dynamometer made from a generator, with the electrical power dissipated with resistive heating elements. We found that intake air density increases with capacitor size as theoretically predicted, ranging from 40 to 60 percent depending on heat transfer. Our experiment was able to produce 29 percent more power compared to using natural aspiration. These results validated that an air capacitor and turbocharger may be a simple, cost effective means of increasing the power density of single cylinder engines.

  2. Liquid-cooled cylinder assembly in internal-combustion engine

    SciTech Connect

    Nakano, H.; Ozu, T.

    1987-02-03

    This patent describes an internal-combustion engine of the piston type having at least one cylinder assembly comprising a cylinder head and a cylinder liner capped at the upper end thereof by the cylinder head. The improvement described here comprises: a reinforcing ring fixedly fitted around the outer cylindrical surface of the upper end part of the cylinder liner; recesses grooved in and at respective positions around the outer cylindrical surface; passageways in the reinforcing ring and communicating with respective the recesses to form cooling-liquid passageways; the upper end part of the cylinder liner having an inverted frustoconical shape with the outer diameter thereof increasing gradually in the direction toward the cylinder head. The inner wall surface of the reinforcing ring is formed to fit tightly around the upper end part in a lead-proof manner for preventing relative displacements between the cylinder head, the cylinder liner, and the reinforcing ring.

  3. Natural convection in a horizontal cylinder with axial rotation

    NASA Astrophysics Data System (ADS)

    Sánchez, Odalys; Mercader, Isabel; Batiste, Oriol; Alonso, Arantxa

    2016-06-01

    We study the problem of thermal convection in a laterally heated horizontal cylinder rotating about its axis. A cylinder of aspect ratio Γ =H /2 R =2 containing a small Prandtl number fluid (σ =0.01 ) representative of molten metals and molten semiconductors at high temperature is considered. We focus on a slow rotation regime (Ω <8 ), where the effects of rotation and buoyancy forces are comparable. The Navier-Stokes and energy equations with the Boussinesq approximation are solved numerically to calculate the basic states, analyze their linear stability, and compute several secondary flows originated from the instabilities. Due to the confined cylindrical geometry—the presence of lateral walls and lids—all the flows are completely three dimensional, even the basic steady states. Results characterizing the basic states as the rotation rate increases are presented. As it occurred in the nonrotating case for higher values of the Prandtl number, two curves of steady states with the same symmetric character coexist for moderate values of the Rayleigh number. In the range of Ω considered, rotation has a stabilizing effect only for very small values. As the value of the rotation rate approaches Ω =3.5 and Ω =4.5 , the scenario of bifurcations becomes more complex due to the existence in both cases of very close bifurcations of codimension 2, which in the latter case involve both curves of symmetric solutions.

  4. Natural convection in a horizontal cylinder with axial rotation.

    PubMed

    Sánchez, Odalys; Mercader, Isabel; Batiste, Oriol; Alonso, Arantxa

    2016-06-01

    We study the problem of thermal convection in a laterally heated horizontal cylinder rotating about its axis. A cylinder of aspect ratio Γ=H/2R=2 containing a small Prandtl number fluid (σ=0.01) representative of molten metals and molten semiconductors at high temperature is considered. We focus on a slow rotation regime (Ω<8), where the effects of rotation and buoyancy forces are comparable. The Navier-Stokes and energy equations with the Boussinesq approximation are solved numerically to calculate the basic states, analyze their linear stability, and compute several secondary flows originated from the instabilities. Due to the confined cylindrical geometry-the presence of lateral walls and lids-all the flows are completely three dimensional, even the basic steady states. Results characterizing the basic states as the rotation rate increases are presented. As it occurred in the nonrotating case for higher values of the Prandtl number, two curves of steady states with the same symmetric character coexist for moderate values of the Rayleigh number. In the range of Ω considered, rotation has a stabilizing effect only for very small values. As the value of the rotation rate approaches Ω=3.5 and Ω=4.5, the scenario of bifurcations becomes more complex due to the existence in both cases of very close bifurcations of codimension 2, which in the latter case involve both curves of symmetric solutions. PMID:27415364

  5. Sky reconstruction for the Tianlai cylinder array

    NASA Astrophysics Data System (ADS)

    Zhang, Jiao; Zuo, Shi-Fan; Ansari, Reza; Chen, Xuelei; Li, Yi-Chao; Wu, Feng-Quan; Campagne, Jean-Eric; Magneville, Christophe

    2016-10-01

    We apply our sky map reconstruction method for transit type interferometers to the Tianlai cylinder array. The method is based on spherical harmonic decomposition, and can be applied to a cylindrical array as well as dish arrays and we can compute the instrument response, synthesized beam, transfer function and noise power spectrum. We consider cylinder arrays with feed spacing larger than half a wavelength and, as expected, we find that the arrays with regular spacing have grating lobes which produce spurious images in the reconstructed maps. We show that this problem can be overcome using arrays with a different feed spacing on each cylinder. We present the reconstructed maps, and study the performance in terms of noise power spectrum, transfer function and beams for both regular and irregular feed spacing configurations.

  6. Plug-in Electric Vehicle Interactions with a Small Office Building: An Economic Analysis using DER-CAM

    SciTech Connect

    Momber, Ilan; Gomez, Tomás; Venkataramanan, Giri; Stadler, Michael; Beer, Sebastian; Lai, Judy; Marnay, Chris; Battaglia, Vincent

    2010-06-01

    It is generally believed that plug-in electric vehicles (PEVs) offer environmental and energy security advantages compared to conventional vehicles. Policies are stimulating electric transportation deployment, and PEV adoption may grow significantly. New technology and business models are being developed to organize the PEV interface and their interaction with the wider grid. This paper analyzes the PEVs' integration into a building's Energy Management System (EMS), differentiating between vehicle to macrogrid (V2M) and vehicle to microgrid (V2m) applications. This relationship is modeled by the Distributed Energy Resources Customer Adoption Model (DER-CAM), which finds optimal equipment combinations to meet microgrid requirements at minimum cost, carbon footprint, or other criteria. Results derive battery value to the building and the possibility of a contractual affiliation sharing the benefit. Under simple annual fixed payments and energy exchange agreements, vehicles are primarily used to avoid peak demand charges supplying cheaper off-peak electricity to the building during workdays.

  7. Gas adsorption and desorption effects on cylinders and their importance for long-term gas records

    NASA Astrophysics Data System (ADS)

    Leuenberger, M. C.; Schibig, M. F.; Nyfeler, P.

    2015-12-01

    .0003 ppm °C-1 for aluminium cylinders. The reversed temperature dependence for aluminium cylinders points to significantly lower desorption energies than for steel cylinders and due to the small values, they might at least partly be influenced by temperature, permeation from/to sealing materials, and gas-consumption-induced pressure changes. Temperature coefficients for CH4, CO, and H2O adsorption were, within their error bands, insignificant. These results do indicate the need for careful selection and usage of gas cylinders for high-precision calibration purposes such as requested in trace gas applications.

  8. UF{sub 6} cylinder inspections at PGDP

    SciTech Connect

    Lamb, G.W.; Whinnery, W.N.

    1991-12-31

    Routine inspections of all UF{sub 6} cylinders at the Paducah Gaseous Diffusion Plant have been mandated by the Department of Energy. A specific UF{sub 6} cylinder inspection procedure for what items to inspect and training for the operators prior to inspection duty are described. The layout of the cylinder yards and the forms used in the inspections are shown. The large number of cylinders (>30,000) to inspect and the schedule for completion on the mandated time table are discussed. Results of the inspections and the actions to correct the deficiencies are explained. Future inspections and movement of cylinders for relocation of certain cylinder yards are defined.

  9. A Hybrid Approach To Tandem Cylinder Noise

    NASA Technical Reports Server (NTRS)

    Lockard, David P.

    2004-01-01

    Aeolian tone generation from tandem cylinders is predicted using a hybrid approach. A standard computational fluid dynamics (CFD) code is used to compute the unsteady flow around the cylinders, and the acoustics are calculated using the acoustic analogy. The CFD code is nominally second order in space and time and includes several turbulence models, but the SST k - omega model is used for most of the calculations. Significant variation is observed between laminar and turbulent cases, and with changes in the turbulence model. A two-dimensional implementation of the Ffowcs Williams-Hawkings (FW-H) equation is used to predict the far-field noise.

  10. Development of plasma spray coated cylinder liners

    SciTech Connect

    Tricard, M.; Hagan, J.; Redington, P.; Subramanian, K.; Haselkorn, M.

    1996-09-01

    Improved fuel economy and reduction of emissions can be achieved by insulation of the combustion chamber components to reduce heat rejection. However, such insulation will also increase the operating temperature of the piston ring/cylinder liner interface from approximately 150 C to over 300 C. Since existing ring/liner materials cannot withstand these higher operating temperatures alternatives are needed for this critical tribological interface. This paper describes the development of a cost effective ID grinding technique for machining the bores of plasma sprayed diesel engine cylinder liners.

  11. Controllable parabolic-cylinder optical rogue wave.

    PubMed

    Zhong, Wei-Ping; Chen, Lang; Belić, Milivoj; Petrović, Nikola

    2014-10-01

    We demonstrate controllable parabolic-cylinder optical rogue waves in certain inhomogeneous media. An analytical rogue wave solution of the generalized nonlinear Schrödinger equation with spatially modulated coefficients and an external potential in the form of modulated quadratic potential is obtained by the similarity transformation. Numerical simulations are performed for comparison with the analytical solutions and to confirm the stability of the rogue wave solution obtained. These optical rogue waves are built by the products of parabolic-cylinder functions and the basic rogue wave solution of the standard nonlinear Schrödinger equation. Such rogue waves may appear in different forms, as the hump and paw profiles.

  12. Stress tests on cylinders and aluminum panels

    NASA Technical Reports Server (NTRS)

    Sobel, L. H.; Agarwal, B. L.

    1974-01-01

    An optimization study of composite stiffened cylinders is discussed. The mathematical model for the buckling has been coupled successfully with the optimization program AESOP. The buckling analysis is based on the use of the smeared theory for the buckling of stiffened orthotropic cylindrical shells. The loading, radius, and length of the cylinder are assumed to be known parameters. An optimum solution gives the value of cross-sectional dimensions and laminate orientations. The different types of buckling modes are identified. Mathematical models are developed to show the relationships of the parameters.

  13. Cylinder wakes in flowing soap films

    SciTech Connect

    Vorobieff, P.; Ecke, R.E. ); Vorobieff, P. )

    1999-09-01

    We present an experimental characterization of cylinder wakes in flowing soap films. From instantaneous velocity and thickness fields, we find the vortex-shedding frequency, mean-flow velocity, and mean-film thickness. Using the empirical relationship between the Reynolds and Strouhal numbers obtained for cylinder wakes in three dimensions, we estimate the effective soap-film viscosity and its dependence on film thickness. We also compare the decay of vorticity with that in a simple Rankine vortex model with a dissipative term to account for air drag. [copyright] [ital 1999] [ital The American Physical Society

  14. Finite element calculations of viscoelastic fluid flow in a spinning and nutating cylinder

    NASA Astrophysics Data System (ADS)

    Rosenblat, S.; Gooding, A.; Engleman, M. S.

    1986-12-01

    An investigation has been performed of the flow of a non-Newtonian liquid in a spinning and nutating cylinder. An approximate analysis has been effected on the assumption that the ratio of coning rate to spin rate is small and applied to the case of a cylinder of infinite length. A numerical calculation has been performed for the actual flow of two specified non-Newtonian liquids, using the finite element code FIDAP. Results are presented in both graphical and tabular form showing flow fields and calculated values of the despin moment for ranges of parameters. The question of appropriate representation of the liquid's non-Newtonian behavior is discussed.

  15. Finite-amplitude pressure waves in the radial mode of a cylinder

    NASA Technical Reports Server (NTRS)

    Kubo, I.; Moore, F. K.

    1972-01-01

    A numerical study of finite-strength, isentropic pressure waves transverse to the axis of a circular cylinder was made for the radial resonant mode. The waves occur in a gas otherwise at rest, filling the cylinder. A method of characteristics was used for the numerical solution. For small but finite amplitudes, calculations indicate the existence of waves of permanent potential form. For larger amplitudes, a shock is indicated to occur. The critical value of the initial amplitude parameter in the power series is found to be 0.06 to 0.08, under various types of initial conditions.

  16. A simple method for creating a robust optical vortex beam with a single cylinder lens

    NASA Astrophysics Data System (ADS)

    Nam, Hannarae Annie; Cohen, Martin G.; Noé, John W.

    2011-06-01

    We describe a simple method for creating Laguerre-Gauss (LG) optical vortex beams from Hermite-Gauss (HG) modes with a single cylinder lens. The diverging vortex created by the cylinder lens has the correct intensity distribution in the far-field but its residual longitudinal astigmatism causes the vortex to revert to the original HG mode when it is brought to a focus. We show that an appropriate small tilt of the focusing lens can prevent this effect by introducing a compensating astigmatism. The corrected vortex is a good approximation to an exact LG mode and should be useful for a variety of demonstrations and experiments.

  17. Optimizing power cylinder lubrication on a large bore natural gas engine

    NASA Astrophysics Data System (ADS)

    Luedeman, Matthew R.

    More than 6000 integral compressors, located along America's natural gas pipelines, pump natural gas across the United States. These compressors are powered by 2-stroke, large bore natural gas burning engines. Lowering the operating costs, reducing the emissions, and ensuring that these engines remain compliant with future emission regulations are the drivers for this study. Substantial research has focused on optimizing efficiency and reducing the fuel derived emissions on this class of engine. However, significantly less research has focused on the effect and reduction of lubricating oil derived emissions. This study evaluates the impact of power cylinder lubricating oil on overall engine emissions with an emphasis on reducing oxidation catalyst poisoning. A traditional power cylinder lubricator was analyzed; power cylinder lubricating oil was found to significantly impact exhaust emissions. Lubricating oil was identified as the primary contributor of particulate matter production in a large bore natural gas engine. The particulate matter was determined to be primarily organic carbon, and most likely direct oil carryover of small oil droplets. The particulate matter production equated to 25% of the injected oil at a nominal power cylinder lubrication rate. In addition, power cylinder friction is considered the primary contributor to friction loss in the internal combustion engine. This study investigates the potential for optimizing power cylinder lubrication by controlling power cylinder injection to occur at the optimal time in the piston cycle. By injecting oil directly into the ring pack, it is believed that emissions, catalyst poisoning, friction, and wear can all be reduced. This report outlines the design and theory of two electronically controlled lubrication systems. Experimental results and evaluation of one of the systems is included.

  18. Heat Transfer Over the Circumference of a Heated Cylinder in Transverse Flow

    NASA Technical Reports Server (NTRS)

    Schmidt, Ernst; Wenner, Karl

    1943-01-01

    A method for recording the local heat-transfer coefficients on bodies in flow was developed. The cylinder surface was kept at constant temperature by the condensation of vapor except for a narrow strip which is heated separately to the same temperature by electricity. The heat-transfer coefficient at each point was determined from the electric heat output and the temperature increase. The distribution of the heat transfer along the circumference of cylinders was recorded over a range of Reynolds numbers of from 5000 to 426,000. The pressure distribution was measured at the same time. At Reynolds numbers up to around 100,000 high maximums of the heat transfer occurred in the forward stagnation point at and on the rear side at 180C, while at around 80 the heat-transfer coefficient on both sides of the cylinder behind the forward stagnation point manifested distinct minimums. Two other maximums occurred at around 115 C behind the forward stagnation point between 170,000 and 426,000. At 426,000 the heat transfer at the location of those maximums was almost twice as great as in the forward stagnation point, and the rear half of the cylinder diffused about 60 percent of the entire heat, The tests are compared with the results of other experimental and theoretical investigations.

  19. Fano-like resonance emerging from magnetic and electric plasmon mode coupling in small arrays of gold particles

    NASA Astrophysics Data System (ADS)

    Bakhti, Saïd; Tishchenko, Alexandre V.; Zambrana-Puyalto, Xavier; Bonod, Nicolas; Dhuey, Scott D.; Schuck, P. James; Cabrini, Stefano; Alayoglu, Selim; Destouches, Nathalie

    2016-09-01

    In this work we theoretically and experimentally analyze the resonant behavior of individual 3 × 3 gold particle oligomers illuminated under normal and oblique incidence. While this structure hosts both dipolar and quadrupolar electric and magnetic delocalized modes, only dipolar electric and quadrupolar magnetic modes remain at normal incidence. These modes couple into a strongly asymmetric spectral response typical of a Fano-like resonance. In the basis of the coupled mode theory, an analytical representation of the optical extinction in terms of singular functions is used to identify the hybrid modes emerging from the electric and magnetic mode coupling and to interpret the asymmetric line profiles. Especially, we demonstrate that the characteristic Fano line shape results from the spectral interference of a broad hybrid mode with a sharp one. This structure presents a special feature in which the electric field intensity is confined on different lines of the oligomer depending on the illumination wavelength relative to the Fano dip. This Fano-type resonance is experimentally observed performing extinction cross section measurements on arrays of gold nano-disks. The vanishing of the Fano dip when increasing the incidence angle is also experimentally observed in accordance with numerical simulations.

  20. Fano-like resonance emerging from magnetic and electric plasmon mode coupling in small arrays of gold particles.

    PubMed

    Bakhti, Saïd; Tishchenko, Alexandre V; Zambrana-Puyalto, Xavier; Bonod, Nicolas; Dhuey, Scott D; Schuck, P James; Cabrini, Stefano; Alayoglu, Selim; Destouches, Nathalie

    2016-01-01

    In this work we theoretically and experimentally analyze the resonant behavior of individual 3 × 3 gold particle oligomers illuminated under normal and oblique incidence. While this structure hosts both dipolar and quadrupolar electric and magnetic delocalized modes, only dipolar electric and quadrupolar magnetic modes remain at normal incidence. These modes couple into a strongly asymmetric spectral response typical of a Fano-like resonance. In the basis of the coupled mode theory, an analytical representation of the optical extinction in terms of singular functions is used to identify the hybrid modes emerging from the electric and magnetic mode coupling and to interpret the asymmetric line profiles. Especially, we demonstrate that the characteristic Fano line shape results from the spectral interference of a broad hybrid mode with a sharp one. This structure presents a special feature in which the electric field intensity is confined on different lines of the oligomer depending on the illumination wavelength relative to the Fano dip. This Fano-type resonance is experimentally observed performing extinction cross section measurements on arrays of gold nano-disks. The vanishing of the Fano dip when increasing the incidence angle is also experimentally observed in accordance with numerical simulations.

  1. Fano-like resonance emerging from magnetic and electric plasmon mode coupling in small arrays of gold particles

    PubMed Central

    Bakhti, Saïd; Tishchenko, Alexandre V.; Zambrana-Puyalto, Xavier; Bonod, Nicolas; Dhuey, Scott D.; Schuck, P. James; Cabrini, Stefano; Alayoglu, Selim; Destouches, Nathalie

    2016-01-01

    In this work we theoretically and experimentally analyze the resonant behavior of individual 3 × 3 gold particle oligomers illuminated under normal and oblique incidence. While this structure hosts both dipolar and quadrupolar electric and magnetic delocalized modes, only dipolar electric and quadrupolar magnetic modes remain at normal incidence. These modes couple into a strongly asymmetric spectral response typical of a Fano-like resonance. In the basis of the coupled mode theory, an analytical representation of the optical extinction in terms of singular functions is used to identify the hybrid modes emerging from the electric and magnetic mode coupling and to interpret the asymmetric line profiles. Especially, we demonstrate that the characteristic Fano line shape results from the spectral interference of a broad hybrid mode with a sharp one. This structure presents a special feature in which the electric field intensity is confined on different lines of the oligomer depending on the illumination wavelength relative to the Fano dip. This Fano-type resonance is experimentally observed performing extinction cross section measurements on arrays of gold nano-disks. The vanishing of the Fano dip when increasing the incidence angle is also experimentally observed in accordance with numerical simulations. PMID:27580515

  2. Fano-like resonance emerging from magnetic and electric plasmon mode coupling in small arrays of gold particles.

    PubMed

    Bakhti, Saïd; Tishchenko, Alexandre V; Zambrana-Puyalto, Xavier; Bonod, Nicolas; Dhuey, Scott D; Schuck, P James; Cabrini, Stefano; Alayoglu, Selim; Destouches, Nathalie

    2016-01-01

    In this work we theoretically and experimentally analyze the resonant behavior of individual 3 × 3 gold particle oligomers illuminated under normal and oblique incidence. While this structure hosts both dipolar and quadrupolar electric and magnetic delocalized modes, only dipolar electric and quadrupolar magnetic modes remain at normal incidence. These modes couple into a strongly asymmetric spectral response typical of a Fano-like resonance. In the basis of the coupled mode theory, an analytical representation of the optical extinction in terms of singular functions is used to identify the hybrid modes emerging from the electric and magnetic mode coupling and to interpret the asymmetric line profiles. Especially, we demonstrate that the characteristic Fano line shape results from the spectral interference of a broad hybrid mode with a sharp one. This structure presents a special feature in which the electric field intensity is confined on different lines of the oligomer depending on the illumination wavelength relative to the Fano dip. This Fano-type resonance is experimentally observed performing extinction cross section measurements on arrays of gold nano-disks. The vanishing of the Fano dip when increasing the incidence angle is also experimentally observed in accordance with numerical simulations. PMID:27580515

  3. Reliable, Efficient and Cost-Effective Electric Power Converter for Small Wind Turbines Based on AC-link Technology

    SciTech Connect

    Darren Hammell; Mark Holveck; DOE Project Officer - Keith Bennett

    2006-08-01

    Grid-tied inverter power electronics have been an Achilles heel of the small wind industry, providing opportunity for new technologies to provide lower costs, greater efficiency, and improved reliability. The small wind turbine market is also moving towards the 50-100kW size range. The unique AC-link power conversion technology provides efficiency, reliability, and power quality advantages over existing technologies, and Princeton Power will adapt prototype designs used for industrial asynchronous motor control to a 50kW small wind turbine design.

  4. Flame Movement and Pressure Development in an Engine Cylinder

    NASA Technical Reports Server (NTRS)

    Marvin, Charles F , Jr; Best, Robert D

    1932-01-01

    This investigation describes a visual method for making stroboscopic observations, through a large number of small windows, of the spread of flame throughout the combustion chamber of a gasoline engine. Data, secured by this method on a small engine burning gaseous fuels, are given to show the effects of mixture ratio, spark advance, engine speed, charge density, degree of dilution, compression ratio, and fuel composition on flame movement in the cylinder. Partial indicator diagrams showing pressure development during the combustion period are included. Although present knowledge is not sufficient to permit qualitative evaluation of the separate effects on flame movement of chemical reaction velocity, thermal expansion of burned gases, resonance, turbulence, and piston movement, the qualitative influence of certain of these factors on some of the diagrams is indicated.

  5. Stabilization of Taylor-Couette flow due to time-periodic outer cylinder oscillation

    NASA Technical Reports Server (NTRS)

    Murray, B. T.; Mcfadden, G. B.; Coriell, S. R.

    1990-01-01

    The linear stability of circular Couette flow between concentric infinite cylinders is considered for the case when the inner cylinder is rotated at a constant angular velocity and the outer cylinder is driven sinusoidally in time with zero mean rotation. This configuration was studied experimentally by Walsh and Donnelly. The critical Reynolds numbers calculated from linear stability theory agree well with the experimental values, except at large modulation amplitudes and small frequencies. The theoretical values are obtained using Floquet theory implemented in two distinct approaches: a truncated Fourier series representation in time, and a fundamental solution matrix based on a Chebyshev pseudospectral representation in space. For large amplitude, low frequency modulation, the linear eigenfunctions are temporally complex, consisting of a quiescent region followed by rapid change in the perturbed flow velocities.

  6. Crystalglobulinemia with fulminant course with cylinder-like bodies on peripheral blood smear.

    PubMed

    Kawaguchi, Takeshi; Kariya, Yumi; Matsuda, Motohiro; Kubo, Kazuyoshi; Miyauchi, Syunichi; Kusumoto, Norio; Ueno, Shiro; Takajo, Ichiro; Nagatomo, Yasuhiro; Tahira, Yuki; Yamamoto, Syoko; Yorita, Kenji; Kataoka, Hiroaki; Okayama, Akihiko

    2014-01-01

    A 63-year-old woman presented to our hospital with fever, purpura and pain in both legs and died 4 days after admission. Her blood smear and skin biopsy showed cylinder-like bodies (20×120 μm). She was diagnosed to have monoclonal gammopathy (IgG, lambda type). An autopsy revealed cylinder-like bodies in the vasculature of various organs. We noted a proliferation of atypical plasma cells in her bone marrow, suggesting pre-existing myeloma. Crystalglobulinemia is a rare manifestation of hypergammaglobulinemia that can cause multiple embolisms of the small vessels, and this resulted in the patient's fulminant course. The identification of cylinder-like bodies in the peripheral blood may help in reaching a diagnosis in such cases. PMID:25130123

  7. Observations of the stratorotational instability in rotating concentric cylinders

    NASA Astrophysics Data System (ADS)

    Ibanez, Ruy; Swinney, Harry L.; Rodenborn, Bruce

    2016-09-01

    We study the stability of density stratified flow between corotating vertical cylinders with rotation rates Ωo<Ωi and radius ratio ri/ro=0.877 , where subscripts o and i refer to the outer and inner cylinders. Just as in stellar and planetary accretion disks, the flow has rotation, anticyclonic shear, and a stabilizing density gradient parallel to the rotation axis. The primary instability of the laminar state leads not to axisymmetric Taylor vortex flow but to a nonaxisymmetric stratorotational instability (SRI). The present work extends the range of Reynolds numbers and buoyancy frequencies [N =√{(-g /ρ )(∂ ρ /∂ z ) }] examined in previous experiments. We present the first experimental results for the axial wavelength λ of the instability as a function of the internal Froude number, Fr=Ωi/N ; λ increases by nearly an order of magnitude over the range of Fr examined. For small outer cylinder Reynolds number, the SRI occurs for inner inner Reynolds number larger than for the axisymmetric Taylor vortex flow (i.e., the SRI is more stable). For somewhat larger outer Reynolds numbers the SRI occurs for smaller inner Reynolds numbers than Taylor vortex flow and even below the Rayleigh stability line for an inviscid fluid. Shalybkov and Rüdiger [Astron. Astrophys. 438, 411 (2005), 10.1051/0004-6361:20042492] proposed that the laminar state of a stably stratified rotating shear flow should be stable for Ωo/Ωi>ri/ro , but we find that this stability criterion is violated for N sufficiently large. At large Reynolds number the primary instability is not the SRI but a previously unreported nonperiodic state that mixes the fluid.

  8. Energetically efficient proportional-integral-differential (PID) control of wake vortices behind a circular cylinder

    NASA Astrophysics Data System (ADS)

    Das, Pramode K.; Mathew, Sam; Shaiju, A. J.; Patnaik, B. S. V.

    2016-02-01

    The control of vortex shedding behind a circular cylinder is a precursor to a wide range of external shear flow problems in engineering, in particular the flow-induced vibrations. In the present study, numerical simulation of an energetically efficient active flow control strategy is proposed, for the control of wake vortices behind a circular cylinder at a low Reynolds number of 100. The fluid is assumed to be incompressible and Newtonian with negligible variation in properties. Reflectionally symmetric controllers are designed such that, they are located on a small sector of the cylinder over which, tangential sliding mode control is imparted. In the field of modern controls, proportional (P), integral (I) and differential (D) control strategies and their numerous combinations are extremely popular in industrial practice. To impart suitable control actuation, the vertically varying lift force on the circular cylinder, is synthesised for the construction of an error term. Four different types of controllers considered in the present study are, P, I, PI and PID. These controllers are evaluated for their energetic efficiency and performance. A linear quadratic optimal control problem is formulated, to minimise the cost functional. By performing detailed simulations, it was observed that, the system is energetically efficient, even when the twin eddies are still persisting behind the circular cylinder. To assess the adaptability of the controllers, the actuators were switched on and off to study their dynamic response.

  9. Experimental evaluation of sound produced by two cylinders in a cross flow in various configurations

    NASA Astrophysics Data System (ADS)

    Bilka, Michael; Kerrian, Peter; Morris, Scott

    2012-11-01

    Cylinders in a cross flow is a canonical test case that is considered representative of industrial fluid flow problems, such as heat exchangers and aircraft landing gear. The general configurations are cylinders in tandem, parallel or staggered, which lead to several interesting flow phenomena such as wake cavity/wake interaction effects (tandem), symmetric/asymmetric wake behavior (parallel) or wake interaction/coanda effects (staggered), depending on relative location of the cylinders. In many cases, it is important to not only understand the flow interaction between the cylinders but also the acoustic consequence of such configurations. However, information on the acoustical behavior based on these configurations is relatively small compared to that of the steady aerodynamic and flow interaction behavior. The present work investigates the acoustic spectral properties of these configurations in order to characterize the sound produced by cylinder proximity and wake effects. The spectra are measured using an acoustic beam-forming technique to identify the sources and remove spurious content from the spectra.

  10. The dish-Rankine SCSTPE program (Engineering Experiment no. 1). [systems engineering and economic analysis for a small community solar thermal electric system

    NASA Technical Reports Server (NTRS)

    Pons, R. L.; Grigsby, C. E.

    1980-01-01

    Activities planned for phase 2 Of the Small Community Solar Thermal Power Experiment (PFDR) program are summarized with emphasis on a dish-Rankine point focusing distributed receiver solar thermal electric system. Major design efforts include: (1) development of an advanced concept indirect-heated receiver;(2) development of hardware and software for a totally unmanned power plant control system; (3) implementation of a hybrid digital simulator which will validate plant operation prior to field testing; and (4) the acquisition of an efficient organic Rankine cycle power conversion unit. Preliminary performance analyses indicate that a mass-produced dish-Rankine PFDR system is potentially capable of producing electricity at a levelized busbar energy cost of 60 to 70 mills per KWh and with a capital cost of about $1300 per KW.

  11. Breached cylinder incident at the Portsmouth gaseous diffusion plant

    SciTech Connect

    Boelens, R.A.

    1991-12-31

    On June 16, 1990, during an inspection of valves on partially depleted product storage cylinders, a 14-ton partially depleted product cylinder was discovered breached. The cylinder had been placed in long-term storage in 1977 on the top row of Portsmouth`s (two rows high) storage area. The breach was observed when an inspector noticed a pile of green material along side of the cylinder. The breach was estimated to be approximately 8- inches wide and 16-inches long, and ran under the first stiffening ring of the cylinder. During the continuing inspection of the storage area, a second 14-ton product cylinder was discovered breached. This cylinder was stacked on the bottom row in the storage area in 1986. This breach was also located adjacent to a stiffening ring. This paper will discuss the contributing factors of the breaching of the cylinders, the immediate response, subsequent actions in support of the investigation, and corrective actions.

  12. [A cylinder aneurysm of a penile prosthesis].

    PubMed

    Pannek, J; Bartel, P; Göcking, K

    2011-07-01

    Herniation of a penile prosthesis (cylinder aneurysm) is an extremely rare complication of penile prosthesis surgery. We report the first case of such an aneurysm in a patient with spinal cord injury. The treatment of choice is surgical revision with replacement of the faulty device. Filling of the implanted system with contrast media facilitates preoperative diagnostic workup. PMID:21567276

  13. Rotating Cylinder Treatment System Demonstration (Presentation)

    EPA Science Inventory

    In August 2008, a rotating cylinder treatment system (RCTSTM) demonstration was conducted near Gladstone, CO. The RCTSTM is a novel technology developed to replace the aeration/oxidation and mixing components of a conventional lime precipitation treatment s...

  14. Electromagnetic scattering by arbitrarily oriented ice cylinders.

    PubMed

    Liou, K N

    1972-03-01

    The scattering of electromagnetic waves by arbitrarily oriented, infinitely long circular cylinders is solved by following the procedures outlined by van de Hulst. The far-field intensities for two cases of a linearly polarized incident wave are derived. The scattering coefficients involve the Bessel functions of the first kind, the Hankel functions of the second kind, and their first derivatives. Calculations are made for ice cylinders at three wavelengths: 0.7 micro, 3 micro, and 10 micro. The numerical results of intensity coefficients are presented as functions of the observation angle ø. A significant cross-polarized component for the scattered field, which vanishes only at normal incidence, is obtained. It is also shown that the numerous interference maxima and minima of the intensity coefficients due to single-particle effects depend on the size parameter x as well as on the oblique incident angle alpha. Since cylinder-type particles are often observed in ice clouds, the light-scattering calculations performed for a cir ular cylinder in this paper should be of use in the study of cloud microstructure.

  15. The Potential of Combined Heat and Power Generation, Wind Power Generation and Load Management Techniques for Cost Reduction in Small Electricity Supply Systems.

    NASA Astrophysics Data System (ADS)

    Bass, Jeremy Hugh

    Available from UMI in association with The British Library. Requires signed TDF. An evaluation is made of the potential fuel and financial savings possible when a small, autonomous diesel system sized to meet the demands of an individual, domestic consumer is adapted to include: (1) combined heat and power (CHP) generation, (2) wind turbine generation, (3) direct load control. The potential of these three areas is investigated by means of time-step simulation modelling on a microcomputer. Models are used to evaluate performance and a Net Present Value analysis used to assess costs. A cost/benefit analysis then enables those areas, or combination of areas, that facilitate and greatest savings to be identified. The modelling work is supported by experience gained from the following: (1) field study of the Lundy Island wind/diesel system, (2) laboratory testing of a small diesel generator set, (3) study of a diesel based CHP unit, (4) study of a diesel based direct load control system, (5) statistical analysis of data obtained from the long-term monitoring of a large number of individual household's electricity consumption. Rather than consider the consumer's electrical demand in isolation, a more flexible approach is adopted, with consumer demand being regarded as the sum of primarily two components: a small, electricity demand for essential services and a large, reschedulable demand for heating/cooling. The results of the study indicate that: (1) operating a diesel set in a CHP mode is the best strategy for both financial and fuel savings. A simple retrofit enables overall conversion efficiencies to be increased from 25% to 60%, or greater, at little cost. (2) wind turbine generation in association with direct load control is a most effective combination. (3) a combination of both the above areas enables greatest overall financial savings, in favourable winds resulting in unit energy costs around 20% of those of diesel only operation.

  16. Failure of Non-Circular Composite Cylinders

    NASA Technical Reports Server (NTRS)

    Hyer, M. W.

    2004-01-01

    In this study, a progressive failure analysis is used to investigate leakage in internally pressurized non-circular composite cylinders. This type of approach accounts for the localized loss of stiffness when material failure occurs at some location in a structure by degrading the local material elastic properties by a certain factor. The manner in which this degradation of material properties takes place depends on the failure modes, which are determined by the application of a failure criterion. The finite-element code STAGS, which has the capability to perform progressive failure analysis using different degradation schemes and failure criteria, is utilized to analyze laboratory scale, graphite-epoxy, elliptical cylinders with quasi-isotropic, circumferentially-stiff, and axially-stiff material orthotropies. The results are divided into two parts. The first part shows that leakage, which is assumed to develop if there is material failure in every layer at some axial and circumferential location within the cylinder, does not occur without failure of fibers. Moreover before fibers begin to fail, only matrix tensile failures, or matrix cracking, takes place, and at least one layer in all three cylinders studied remain uncracked, preventing the formation of a leakage path. That determination is corroborated by the use of different degradation schemes and various failure criteria. Among the degradation schemes investigated are the degradation of different engineering properties, the use of various degradation factors, the recursive or non-recursive degradation of the engineering properties, and the degradation of material properties using different computational approaches. The failure criteria used in the analysis include the noninteractive maximum stress criterion and the interactive Hashin and Tsai-Wu criteria. The second part of the results shows that leakage occurs due to a combination of matrix tensile and compressive, fiber tensile and compressive, and inplane

  17. Nonlinear bending and collapse analysis of a poked cylinder and other point-loaded cylinders

    SciTech Connect

    Sobel, L.H.

    1983-06-01

    This paper analyzes the geometrically nonlinear bending and collapse behavior of an elastic, simply supported cylindrical shell subjected to an inward-directed point load applied at midlength. The large displacement analysis results for this thin (R/t = 638) poked cylinder were obtained from the STAGSC-1 finite element computer program. STAGSC-1 results are also presented for two other point-loaded shell problems: a pinched cylinder (R/t = 100), and a venetian blind (R/t = 250).

  18. Nondestructive relative permittivity and loss tangent measurements using a split-cylinder resonator

    NASA Astrophysics Data System (ADS)

    Janezic, Michael Daniel

    To keep pace with the expanding wireless and electronics industries, manufacturers are developing innovative materials for improving system performance, and there is a critical need to accurately characterize the electrical properties of these new materials at microwave frequencies. To address this need, this thesis develops a nondestructive method for measuring the relative permittivity and loss tangent of dielectric substrates using a split-cylinder resonator. Three theoretical models for the split-cylinder resonator are derived using mode-matching, least-squares boundary residual, and Hankel-transform methods, from which one can calculate the relative permittivity and loss tangent of a dielectric substrate from measurements of the split-cylinder resonator's TE0np resonant frequency and quality factor. Each of these models has several advantages over previously published models. First, the accuracy of the relative permittivity measurement is increased because each model accurately models the fringing fields that extend beyond the cylindrical-cavity sections. Second, to increase the accuracy of the loss tangent measurement, each model accurately separates the conductive metal losses of the split-cylinder resonator from the dielectric losses of the substrate. Finally, in contrast to previous models for the split-cylinder resonator that use only the TE011 resonant mode, each of the new models include the higher-order TE0np resonant modes, thereby broadening the frequency range over which one can make relative permittivity and loss tangent measurements. In a comparison of the three models, the mode-matching method was found to be superior on the basis of measurement accuracy and computational speed. Relative permittivity and loss tangent measurements for several dielectric materials are performed using a split-cylinder resonator and are in good agreement with measurements made using a circular-cylindrical cavity, split-post resonator, and dielectric post resonator

  19. 58. (Credit JTL) View looking northeast across steam cylinders of ...

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

    58. (Credit JTL) View looking northeast across steam cylinders of Allis-Chalmers pumping engine. High-pressure cylinder is in foreground, low-pressure cylinder in background with part of Corliss valve gear visible. - McNeil Street Pumping Station, McNeil Street & Cross Bayou, Shreveport, Caddo Parish, LA

  20. 30 CFR 57.16005 - Securing gas cylinders.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Securing gas cylinders. 57.16005 Section 57.16005 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL... Storage and Handling § 57.16005 Securing gas cylinders. Compressed and liquid gas cylinders shall...

  1. 30 CFR 56.16005 - Securing gas cylinders.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Securing gas cylinders. 56.16005 Section 56.16005 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL... and Handling § 56.16005 Securing gas cylinders. Compressed and liquid gas cylinders shall be...

  2. 30 CFR 56.16005 - Securing gas cylinders.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Securing gas cylinders. 56.16005 Section 56.16005 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL... and Handling § 56.16005 Securing gas cylinders. Compressed and liquid gas cylinders shall be...

  3. 30 CFR 57.16005 - Securing gas cylinders.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Securing gas cylinders. 57.16005 Section 57.16005 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL... Storage and Handling § 57.16005 Securing gas cylinders. Compressed and liquid gas cylinders shall...

  4. 49 CFR 176.92 - Cylinders laden in vehicles.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Cylinders laden in vehicles. 176.92 Section 176.92... Requirements for Transport Vehicles Loaded With Hazardous Materials and Transported on Board Ferry Vessels § 176.92 Cylinders laden in vehicles. Any cylinder of Class 2 (compressed gas) material which...

  5. 49 CFR 173.316 - Cryogenic liquids in cylinders.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 2 2013-10-01 2013-10-01 false Cryogenic liquids in cylinders. 173.316 Section... REQUIREMENTS FOR SHIPMENTS AND PACKAGINGS Gases; Preparation and Packaging § 173.316 Cryogenic liquids in cylinders. (a) General requirements. (1) A cylinder may not be loaded with a cryogenic liquid colder...

  6. 49 CFR 173.316 - Cryogenic liquids in cylinders.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 2 2014-10-01 2014-10-01 false Cryogenic liquids in cylinders. 173.316 Section... REQUIREMENTS FOR SHIPMENTS AND PACKAGINGS Gases; Preparation and Packaging § 173.316 Cryogenic liquids in cylinders. (a) General requirements. (1) A cylinder may not be loaded with a cryogenic liquid colder...

  7. Pistons and Cylinders Made of Carbon-Carbon Composite Materials

    NASA Technical Reports Server (NTRS)

    Rivers, H. Kevin (Inventor); Ransone, Philip O. (Inventor); Northam, G. Burton (Inventor); Schwind, Francis A. (Inventor)

    2000-01-01

    An improved reciprocating internal combustion engine has a plurality of engine pistons, which are fabricated from carbon-carbon composite materials, in operative association with an engine cylinder block, or an engine cylinder tube, or an engine cylinder jug, all of which are also fabricated from carbon-carbon composite materials.

  8. Investigation of breached depleted UF{sub 6} cylinders

    SciTech Connect

    DeVan, J.H.

    1991-12-31

    In June 1990, during a three-site inspection of cylinders being used for long-term storage of solid depleted UF{sub 6}, two 14-ton cylinders at Portsmouth, Ohio, were discovered with holes in the barrel section of the cylinders. An investigation team was immediately formed to determine the cause of the failures and their impact on future storage procedures and to recommend corrective actions. Subsequent investigation showed that the failures most probably resulted from mechanical damage that occurred at the time that the cylinders had been placed in the storage yard. In both cylinders evidence pointed to the impact of a lifting lug of an adjacent cylinder near the front stiffening ring, where deflection of the cylinder could occur only by tearing the cylinder. The impacts appear to have punctured the cylinders and thereby set up corrosion processes that greatly extended the openings in the wall and obliterated the original crack. Fortunately, the reaction products formed by this process were relatively protective and prevented any large-scale loss of uranium. The main factors that precipitated the failures were inadequate spacing between cylinders and deviations in the orientations of lifting lugs from their intended horizontal position. After reviewing the causes and effects of the failures, the team`s principal recommendation for remedial action concerned improved cylinder handling and inspection procedures. Design modifications and supplementary mechanical tests were also recommended to improve the cylinder containment integrity during the stacking operation.

  9. 49 CFR 173.316 - Cryogenic liquids in cylinders.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 2 2012-10-01 2012-10-01 false Cryogenic liquids in cylinders. 173.316 Section... REQUIREMENTS FOR SHIPMENTS AND PACKAGINGS Gases; Preparation and Packaging § 173.316 Cryogenic liquids in cylinders. (a) General requirements. (1) A cylinder may not be loaded with a cryogenic liquid colder...

  10. Vibroacoustic Response Data of Stiffened Panels and Cylinders

    NASA Technical Reports Server (NTRS)

    Cabell, Randolph; Klos, Jake; Buehrle, Ralph; Schiller, Noah

    2008-01-01

    NASA has collected vibroacoustic response data on a variety of complex, aerospace structures to support research into numerical modeling of such structures. This data is being made available to the modeling community to promote the development and validation of analysis methods for these types of structures. Existing data from two structures is described, as well as plans for a data set from a third structure. The first structure is a 1.22 m by 1.22 m stiffened aluminum panel, typical of a commercial aircraft sidewall section. The second is an enclosed, stiffened aluminum cylinder, approximately 3.66 m long and 1.22 m in diameter, constructed to resemble a small aircraft fuselage with no windows and a periodic structure. The third structure is a filament-wound composite cylinder with composite stiffeners. Numerous combinations of excitation and response variables were measured on the structures, including: shaker excitation; diffuse acoustic field; velocity response from a laser vibrometer; intensity scans; and point acceleration.

  11. Circular cylinders with soft porous cover for flow noise reduction

    NASA Astrophysics Data System (ADS)

    Geyer, Thomas F.; Sarradj, Ennes

    2016-03-01

    The use of porous materials is one of several approaches to passively control or minimize the generation of flow noise. In order to investigate the possible reduction of noise from struts and other protruding parts (for example components of the landing gear or pantographs), acoustic measurements were taken in a small aeroacoustic wind tunnel on a set of circular cylinders with a soft porous cover. The aim of this study was to identify those materials that result in the best noise reduction, which refers to both tonal noise and broadband noise. The porous covers were characterized by their air flow resistivity, a parameter describing the permeability of an open-porous material. The results show that materials with low air flow resistivities lead to a noticeable flow noise reduction. Thereby, the main effect of the porous cylinder covers is that the spectral peak of the aeolian tone due to vortex shedding appears much narrower, but is not suppressed completely. Based on the measurement results, a basic model for the estimation of the total peak level of the aeolian tone was derived. In addition to the minimization of the vortex shedding noise, a reduction of broadband noise can be observed, especially at higher Reynolds numbers. The noise reduction increases with decreasing air flow resistivity of the porous covers, which means that materials that are highly permeable to air result in the best noise reduction.

  12. General polytropic magnetohydrodynamic cylinder under self-gravity

    NASA Astrophysics Data System (ADS)

    Lou, Yu-Qing; Xing, Heng-Rui

    2016-02-01

    Based on general polytropic (GP) magnetohydrodynamics (MHD), we offer a self-similar dynamic formalism for a magnetized, infinitely long, axially uniform cylinder of axisymmetry under self-gravity with radial and axial flows and with helical magnetic field. We identify two major classes of solution domains and obtain a few valuable MHD integrals in general. We focus on one class that has the freedom of prescribing a GP dynamic equation of state including the isothermal limit and derive analytic asymptotic solutions for illustration. In particular, we re-visit the isothermal MHD problem of Tilley & Pudritz (TP) and find that TP's main conclusion regarding the MHD solution behaviour for a strong ring magnetic field of constant toroidal flux-to-mass ratio Γϕ to be incorrect. As this is important for conceptual scenarios, MHD cylinder models, testing numerical codes and potential observational diagnostics of magnetized filaments in various astrophysical contexts, we show comprehensive theoretical analysis and reasons as well as extensive numerical results to clarify pertinent points in this Letter. In short, for any given Γϕ value be it small or large, the asymptotic radial scaling of the reduced mass density α(x) at sufficiently large x should always be ˜x-4 instead of ˜x-2 contrary to the major claim of TP.

  13. Ignition study of a petrol/CNG single cylinder engine

    NASA Astrophysics Data System (ADS)

    Khan, N.; Saleem, Z.; Mirza, A. A.

    2005-11-01

    Benefits of laser ignition over the electrical ignition system for Compressed Natural Gas (CNG) engines have fuelled automobile industry and led to an extensive research on basic characteristics to switch over to the emerging technologies. This study was undertaken to determine the electrical and physical characteristics of the electric spark ignition of single cylinder petrol/CNG engine to determine minimum ignition requirements and timeline of ignition events to use in subsequent laser ignition study. This communication briefly reviews the ongoing research activities and reports the results of this experimental study. The premixed petrol and CNG mixtures were tested for variation of current and voltage characteristics of the spark with speed of engine. The current magnitude of discharge circuit was found to vary linearly over a wide range of speed but the stroke to stroke fire time was found to vary nonlinearly. The DC voltage profiles were observed to fluctuate randomly during ignition process and staying constant in rest of the combustion cycle. Fire to fire peaks of current amplitudes fluctuated up to 10% of the peak values at constant speed but increased almost linearly with increase in speed. Technical barriers of laser ignition related to threshold minimum ignition energy, inter-pulse durations and firing sequence are discussed. Present findings provide a basic initiative and background information for designing suitable timeline algorithms for laser ignited leaner direct injected CNG engines.

  14. Time-Lapse Seismic Tomography and Electrical Resistivity Mapping of a Small Embankment Dam with Possible Zones of Weakness

    NASA Astrophysics Data System (ADS)

    Wodajo, L. T.; Hickey, C. J.; Song, C. R.

    2013-12-01

    Earthen dam or levee failure can occur with little to no warning. Internal problems such as seepage and piping are among the major causes of failure in earthen embankment dams and levees. Identifying and mitigating these problems requires a cost effective and non-invasive method of investigating these critical structures. This study focuses on the early detection of internal problems such as seepage and piping using time lapse seismic refraction tomography (SRT) and electrical resistivity tomography (ERT). For this study, two quarter scale model dams were built at the USDA-ARS Hydraulic Engineering Research Unit in Stillwater, OK. These dams were constructed with two internal compromised zones that would be susceptible to seepage and piping. The zones consist of a sandy region and a region compacted at lower moisture content. Time lapse seismic refraction and electrical resistivity measurements were conducted over a course of two years to monitor changes in the internal structure of the model dams due to seasonal changes, cyclic loadings and internal erosion failure. The results will provide an insight on how compromised zones due to seepage and piping can be identified at an early stage using both SRT and ERT time-lapse measurements and how joint interpretation of these two methods helps in closely identifying what attributed to the compromised zone. [This research was funded by the department of Homeland Security- sponsored Southeast Region Research Initiative (SERRI) at the Department of Energy's Oak Ridge National Laboratory.

  15. Electrical phosphenes: on the influence of conductivity inhomogeneities and small-scale structures of the orbita on the current density threshold of excitation.

    PubMed

    Lindenblatt, G; Silny, J

    2002-05-01

    Electrical and magnetic phosphenes, perceptions of light as a result of non-adequate stimulation of the eye by electrical current or magnetic induction, respectively, are one of the cornerstones to justify limit values for extreme low-frequency fields specified by statutory regulations. However, the mechanism and place of action, as well as the excitation threshold, remain unknown until now. We suggest that the origin of phosphene excitation is the synaptic layer of the eye. The current density threshold value for electrical phosphene excitation was numerically quantified for this area on the basis of a detailed geometrical model in original submillimetre resolution and specifically measured conductivities in the LF range. The threshold values found were 1.8 A m-2 at 60 Hz and 0.3 A m-2 at 25 Hz. These values are comparable with values of other excitable tissues. It has been shown that the current density threshold for phosphene generation depends on small-scale structures not taken into account by previous models. PMID:12195984

  16. Flow over a cylinder with a hinged-splitter plate

    NASA Astrophysics Data System (ADS)

    Shukla, S.; Govardhan, R. N.; Arakeri, J. H.

    2009-05-01

    Previous work on rigid splitter plates in the wake of a bluff body has shown that the primary vortex shedding can be suppressed for sufficiently long splitter plates. In the present work, we study the problem of a hinged-splitter plate in the wake of a circular cylinder. The splitter plate can rotate about the hinge at the base of the cylinder due to the unsteady fluid forces acting on it, and hence the communication between the two sides of the wake is not totally disrupted as in the rigid splitter plate case. In our study, we investigate this problem in the limit where the stiffness and internal damping associated with the hinge are negligible, and the mass ratio of the splitter plate is small. The experiments show that the splitter plate oscillations increase with Reynolds numbers at low values of Re, and are found to reach a saturation amplitude level at higher Re, Re>4000. This type of saturation amplitude level that appears to continue indefinitely with Re, appears to be related to the fact that there is no structural restoring force, and has been observed previously for transversely oscillating cylinders with no restoring force. In the present case, the saturation tip amplitude level can be up to 0.45D, where D is the cylinder diameter. For this hinged-rigid splitter plate case, it is found that the splitter plate length to cylinder diameter ratio (L/D) is crucial in determining the character and magnitude of the oscillations. For small splitter plate lengths (L/D⩽3.0), the oscillations appear to be nearly periodic with tip amplitudes of about 0.45D nearly independent of L/D. The nondimensional oscillation frequencies (fD/U) on the other hand are found to continuously vary with L/D from fD/U≈0.2 at L/D=1 to fD/U≈0.1 at L/D=3. As the splitter plate length is further increased beyond L/D⩾4.0, the character of the splitter plate oscillations suddenly changes. The oscillations become aperiodic with much smaller amplitudes. In this long splitter plate

  17. The influence of small impurity additions and direct electric current on the kinetics of contact melting in metals

    NASA Astrophysics Data System (ADS)

    Ahkubekov, A. A.; Ahkubekova, S. N.; Enaldieva, O. L.; Orkvasov, T. A.; Sozaev, V. A.

    2008-02-01

    Using the experimental data on contact melting of polycrystalline indium, tin and lead - based solid solutions with low-melting alloys we show that besides the diffusive, adhesive and low - dimensional mechanisms of contact melting it is necessary to take into account the segregational mechanism as well. The surfaces of a contact between the polycrystalline solid solutions and low - melting metals enrich in lower melting components due to the grain-boundary and surface segregation. One can influence on the kinetics of contact melting using alkali metals as impurity additives and applying the direct electric current. For example, the sodium addition to indium results in 3 times expansion of contact layer in the (In + 0.1 at. % Na) - Bi system, but in 2 times shrinking of that layer in the (In + 0.1 at. % Na) - Cd system in comparison to experiments without impurities.

  18. Changes in the electrical properties of pure and doped polymers under the influence of small doses of X-rays

    NASA Astrophysics Data System (ADS)

    Mahmoud, S. A.; Madi, N. K.; Kassem, M. E.; El-Khatib, A.

    A study has been made of the temperature dependence of the d.c. conductivity of pure and borated low density polyethylene LDPE (4% and 8% borax). The above calculations were carried out before and after X-ray irradiation. The irradiation dose was varied from 0 to 1000 rad. The d.c. electrical conductivity of Polyvinyl chloride (PVC) and perspex was measured as a function of temperature ranging from 20°C to 100°C. These samples were irradiated with X-rays of dose 200 rad. The variation of the d.c. conductivity of the treated samples versus temperature was investigated. The results reveal that the d.c. conductivity of LDPE is highly affected by radiation and/or dopant. In addition, the sensitivity of the explored polymers to X-ray irradiation is strongly dependent on its chemical nature.

  19. The experiments and characteristic analysis of the sealless cylinder

    NASA Astrophysics Data System (ADS)

    Kim, Dong-Soo; Bae, Sang-Kyu

    2005-12-01

    Because the general cylinders use sliding seal, The cause the high friction force and adherence phenomenon when They operates in low speed, and the use of the cylinders is not proper in the clean room and high temperature and high pressure environment. Accordingly, in this study, sealless cylinder attaching conical-type piston without seal is proposed to complement the handicap. This paper shows a performance analysis for conical type sealless cylinders and rod bearings. The pistons without seal have partly cylindrical and conical shapes. The 2dimensional Reynolds equation and FD(finite differential) numerical techniques are utilized for the performance analysis. The relationship among self-centering forces and leakage flows are investigated. Also, the optimal design values for a sealless cylinder are presented. A prototype of sealless cylinder which had rod bearing with four pockets, five pockets, and six pockets was manufactured respectively. The leakage flow tests are conducted to evaluate performance of piston and rod bearing in sealless cylinder.

  20. Radiation levels on empty cylinders containing heel material

    SciTech Connect

    Shockley, C.W.

    1991-12-31

    Empty UF{sub 6} cylinders containing heel material were found to emit radiation levels in excess of 200 mr/hr, the maximum amount stated in ORO-651. The radiation levels were as high as 335 mr/hr for thick wall (48X and 48Y) cylinders and 1050 mr/hr for thin wall (48G and 48H) cylinders. The high readings were found only on the bottom of the cylinders. These radiation levels exceeded the maximum levels established in DOT 49 CFR, Part 173.441 for shipment of cylinders. Holding periods of four weeks for thick-wall cylinders and ten weeks for thin-wall cylinders were established to allow the radiation levels to decay prior to shipment.

  1. Upgraded Analytical Model of the Cylinder Test

    SciTech Connect

    Souers, P. Clark; Lauderbach, Lisa; Garza, Raul; Ferranti, Louis; Vitello, Peter

    2013-03-15

    A Gurney-type equation was previously corrected for wall thinning and angle of tilt, and now we have added shock wave attenuation in the copper wall and air gap energy loss. Extensive calculations were undertaken to calibrate the two new energy loss mechanisms across all explosives. The corrected Gurney equation is recommended for cylinder use over the original 1943 form. The effect of these corrections is to add more energy to the adiabat values from a relative volume of 2 to 7, with low energy explosives having the largest correction. The data was pushed up to a relative volume of about 15 and the JWL parameter ω was obtained directly. Finally, the total detonation energy density was locked to the v = 7 adiabat energy density, so that the Cylinder test gives all necessary values needed to make a JWL.

  2. Cylinder Flow Control Using Plasma Actuators

    NASA Astrophysics Data System (ADS)

    Kozlov, Alexey; Thomas, Flint

    2007-11-01

    In this study the results of flow control experiments utilizing single dielectric barrier discharge plasma actuators to control flow separation and unsteady vortex shedding from a circular cylinder in cross-flow are reported. Two optimized quartz dielectric plasma actuators mounted on the cylinder surface utilizing an improved saw-tooth waveform high-voltage generator allowed flow control at Reynolds number approaching supercritical. Using either steady or unsteady actuation, it is demonstrated that the plasma-induced surface blowing gives rise to a local Coanda effect that promotes the maintenance of flow attachment. PIV based flow fields and wake velocity profiles obtained with hot-wire anemometry show large reductions in vortex shedding, wake width and turbulence intensity.

  3. Boundary Layers of Air Adjacent to Cylinders

    PubMed Central

    Nobel, Park S.

    1974-01-01

    Using existing heat transfer data, a relatively simple expression was developed for estimating the effective thickness of the boundary layer of air surrounding cylinders. For wind velocities from 10 to 1000 cm/second, the calculated boundary-layer thickness agreed with that determined for water vapor diffusion from a moistened cylindrical surface 2 cm in diameter. It correctly predicted the resistance for water vapor movement across the boundary layers adjacent to the (cylindrical) inflorescence stems of Xanthorrhoea australis R. Br. and Scirpus validus Vahl and the leaves of Allium cepa L. The boundary-layer thickness decreased as the turbulence intensity increased. For a turbulence intensity representative of field conditions (0.5) and for νwindd between 200 and 30,000 cm2/second (where νwind is the mean wind velocity and d is the cylinder diameter), the effective boundary-layer thickness in centimeters was equal to [Formula: see text]. PMID:16658855

  4. Fluid flow within reciprocating-engine cylinders

    NASA Astrophysics Data System (ADS)

    Awn, A. G.; Spalding, D. B.

    The present investigation has the objective to demonstrate a method of predicting the flow within reciprocating-engine cylinders. The application of this approach can help the engine designer to increase the combustion efficiency and to reduce pollution. The considered method employs finite-difference equations similar to those used by Watkins (1973) and Chong et. al. (1976). The equations are, however, solved by a somewhat different method, and, in addition, an interface-tracking procedure is employed. The numerical procedure is further extended to investigate the scavenging flows in two-stroke engines. One problem studied in the investigation is concerned with the prediction of the velocity field in an engine cylinder during the harmonic motion of a flat-topped piston. A second problem involves the study of the flow behavior during the scavenging cycle in two-stroke engine cyclinders.

  5. Log-rolling block copolymers cylinders

    NASA Astrophysics Data System (ADS)

    Kim, So Youn; Kim, Ye Chan; Kim, Dong Hyup; Kwon, Na Kyung; Register, Richard A.

    Shear has been the most effective method to create long range order of micro- or nano- structures in soft materials. When shear is applied, soft particles or polymers tend to align along the shear direction to minimize the viscous dissipation, thus transverse (so-called ``log-rolling'') alignment is unfavored. In this study, for the first time we report the transverse alignment of cylinder-forming block copolymers. Poly(styrene-b-methyl methacrylate), PS-PMMA, can form a metastable hemicylinder structure when confined in a thin film, and this hemicylinder structure can align either along the shear direction, or transverse to the shear direction (``log-rolling''), depending on the shearing temperature. This unusual ``log-rolling'' behavior is explained by the different chain mobility of the two blocks in PS-PMMA; the rigidity of core cylinder is the critical parameter determining the direction of shear alignment.

  6. Unsteady Flowfield Around Tandem Cylinders as Prototype for Component Interaction in Airframe Noise

    NASA Technical Reports Server (NTRS)

    Khorrami, Meldi R.; Choudhari, Meelan M.; Jenkins, Luther N.; McGinley, Catherine B.

    2005-01-01

    Synergistic application of experiments and numerical simulations is crucial to understanding the underlying physics of airframe noise sources. The current effort is aimed at characterizing the details of the flow interaction between two cylinders in a tandem configuration. This setup is viewed to be representative of several component-level flow interactions that occur when air flows over the main landing gear of large civil transports. Interactions of this type are likely to have a significant impact on the noise radiation associated with the aircraft undercarriage. The paper is focused on two-dimensional, time-accurate flow simulations for the tandem cylinder configuration. Results of the unsteady Reynolds Averaged Navier-Stokes (URANS) computations with a two-equation turbulence model, at a Reynolds number of 0.166 million and a Mach number of 0.166, are presented. The experimental measurements of the same flow field are discussed in a separate paper by Jenkins, Khorrami, Choudhari, and McGinley (2005). Two distinct flow regimes of interest, associated with short and intermediate separation distances between the two cylinders, are considered. Emphasis is placed on understanding both time averaged and unsteady flow features between the two cylinders and in the wake of the rear cylinder. Predicted mean flow quantities and vortex shedding frequencies show reasonable agreement with the measured data for both cylinder spacings. Computations for short separation distance indicate decay of flow unsteadiness with time, which is not unphysical; however, the predicted sensitivity of mean lift coefficient to small angles of attack explains the asymmetric flowfield observed during the experiments.

  7. Precession of a rapidly rotating cylinder flow: traverse through resonance

    NASA Astrophysics Data System (ADS)

    Lopez, Juan; Marques, Francisco

    2014-11-01

    The flow in a rapidly rotating cylinder that is titled and also rotating around another axis can undergo sudden transitions to turbulence. Experimental observations of this have been associated with triadic resonances. The experimental and theoretical results are well-established in the literature, but there remains a lack of understanding of the physical mechanisms at play in the sudden transition from laminar to turbulent flow with very small variations in the governing parameters. Here, we present direct numerical simulations of a traverse in parameter space through an isolated resonance, and describe in detail the bifurcations involved in the sudden transition. U.S. National Science Foundation Grant CBET-1336410 and Spanish Ministry of Education and Science Grant (with FEDER funds) FIS2013-40880.

  8. Temperature distribution in microwave sintering of alumina cylinders

    SciTech Connect

    Thomas, J.R. Jr.; Katz, J.D.; Blake, R.D.

    1994-04-01

    Small cylinders of high-purity alumina were encased in a `casket` of low-density zirconia insulation and heated to sintering temperature in a large multi-mode microwave oven. Optical fiber sensors were used to monitor the temperature at several locations in the system. It was found that the alumina samples heat faster than the zirconia insulation at temperatures above 1000 C, and that the temperature distribution in the sample is essentially uniform during the heating process. A two-dimensional mathematical model of the heat transfer process was developed which reproduces the essential features of the observed phenomena. Literature data for all temperature-dependent properties were incorporated into the model. The model suggests that the alumina samples absorb a significant fraction of the microwave energy.

  9. DDES and IDDES of tandem cylinders.

    SciTech Connect

    Balakrishnan, R.; Garbaruk, A.; Shur, M.; Strelets, M.; Spalart, P.; New Technologies and Services - Russia; St.-Peterburg State Polytechnic Univ.; Boeing Commercial Airplanes

    2010-09-09

    The paper presents an overview of the authors contribution to the BANC-I Workshop on the flow past tandem cylinders (Category 2). It includes an outline of the simulation approaches, numerics, and grid used, the major results of the simulations, their comparison with available experimental data, and some preliminary conclusions. The effect of varying the spanwise period in the simulations is strong for some quantities, and not others.

  10. Dynamical mechanism for coercivity tunability in the electrically controlled FePt perpendicular films with small grain size

    SciTech Connect

    Feng, Chun Li, Xujing; Jiang, Yong; Yu, Guanghua; Yang, Meiyin; Gong, Kui; Li, Baohe

    2014-01-14

    This article reports property manipulations and related dynamical evolution in electromigration controlled FePt perpendicular films. Through altering voltage and treatment time of the power supply applied on the films, electronic momentum was fleetly controlled to manipulate the kinetic energy of Fe and Pt atoms based on momentum exchanges. The electromigration control behavior was proven to cause steerable ordering degree and grain growth in the films without thermal treatment. Processed FePt films with small grain size, high magnetocrystalline anisotropy, and controllable coercivity can be easily obtained. The results provide a novel method for tuning magnetic properties of other L1{sub 0} structured films.

  11. Normalization and source separation of acoustic emission signals for condition monitoring and fault detection of multi-cylinder diesel engines

    NASA Astrophysics Data System (ADS)

    Wu, Weiliang; Lin, Tian Ran; Tan, Andy C. C.

    2015-12-01

    A signal processing technique is presented in this paper to normalize and separate the source of non-linear acoustic emission (AE) signals of a multi-cylinder diesel engine for condition monitoring applications and fault detection. The normalization technique presented in the paper overcomes the long-existing non-linearity problem of AE sensors so that responses measured by different AE sensors can be quantitatively analysed and compared. A source separation algorithm is also developed in the paper to separate the mixture of the normalized AE signals produced by a multi-cylinder diesel engine by utilising the system parameters (i.e., wave attenuation constant and the arrival time delay) of AE wave propagation determined by a standard pencil lead break test on the engine cylinder head. It is shown that the source separation algorithm is able to separate the signal interference of adjacent cylinders from the monitored cylinder once the wave attenuation constant and the arrival time delay along the propagation path are known. The algorithm is particularly useful in the application of AE technique for condition monitoring of small-size diesel engines where signal interference from the neighbouring cylinders is strong.

  12. Gravity-driven fingering simulations for a thin liquid film flowing down the outside of a vertical cylinder.

    PubMed

    Mayo, Lisa C; McCue, Scott W; Moroney, Timothy J

    2013-05-01

    A numerical study is presented to examine the fingering instability of a gravity-driven thin liquid film flowing down the outer wall of a vertical cylinder. The lubrication approximation is employed to derive an evolution equation for the height of the film, which is dependent on a single parameter, the dimensionless cylinder radius. This equation is identified as a special case of that which describes thin film flow down an inclined plane. Fully three-dimensional simulations of the film depict a fingering pattern at the advancing contact line. We find the number of fingers observed in our simulations to be in excellent agreement with experimental observations and a linear stability analysis reported recently by Smolka and SeGall [Phys. Fluids 23, 092103 (2011)]. As the radius of the cylinder decreases, the modes of perturbation have an increased growth rate, thus increasing cylinder curvature partially acts to encourage the contact line instability. In direct competition with this behavior, a decrease in cylinder radius means that fewer fingers are able to form around the circumference of the cylinder. Indeed, for a sufficiently small radius, a transition is observed, at which point the contact line is stable to transverse perturbations of all wave numbers. In this regime, free surface instabilities lead to the development of wave patterns in the axial direction, and the flow features become perfectly analogous to the two-dimensional flow of a thin film down an inverted plane as studied by Lin and Kondic [Phys. Fluids 22, 052105 (2010)]. Finally, we simulate the flow of a single drop down the outside of the cylinder. Our results show that for drops with low volume, the cylinder curvature has the effect of increasing drop speed and hence promoting the phenomenon of pearling. In contrast, drops with much larger volume evolve to form single long rivulets with a similar shape to a finger formed in the aforementioned simulations. PMID:23767631

  13. Flow control of a circular cylinder with O-rings

    NASA Astrophysics Data System (ADS)

    Lim, Hee-Chang; Lee, Sang-Joon

    2004-08-01

    The flow around a circular cylinder is controlled by attaching O-rings to reduce drag force acting on the cylinder. Wind tunnel experiments on the flow around a circular cylinder with and without ring type surface protrusions are carried out to investigate the flow characteristics of the controlled wake. Four experimental models are tested in this study; one smooth cylinder of diameter D (60 mm) and three cylinders fitted with longitudinal O-rings of diameters d=0.0167D, 0.05D and 0.067 D with various pitches. The drag force, mean velocity and turbulence intensity profiles in the near wake behind the cylinders are measured for Reynolds numbers based on the cylinder diameter in the range of ReD=7.8×10 3˜1.2×10 5. Flow field around the cylinders is visualized using a smoke-wire technique to see the flow structure qualitatively. The results are compared with those for a smooth cylinder having the same diameter. At ReD=1.2×10 5, the cylinder fitted with O-rings of d=0.0167 D in a pitch interval of 0.165 D shows the maximum drag reduction of about 9%, compared with the smooth cylinder. The drag reduction effect of O-rings of d=0.067 D is not so high and it has nearly the same value as that of the smooth cylinder. For the O-ring circular, as the Reynolds number increases, the location of peak turbulence intensity shifts downstream and the peak magnitude is decreased. In addition, the vortex shedding frequency has nearly same value as that of the smooth cylinder up to a Reynolds number of 3.2×10 4. Thereafter, the shedding frequency increases and finally disappears as the Reynolds number increases. The visualized flow for the smooth cylinder does not show distinct spanwise variation of flow pattern. However, the size of vortices and vortex formation region formed behind the O-ring cylinder are smaller, compared with the smooth cylinder. In addition, the instantaneous topological flow image shows spanwise variation of V-shaped flow pattern. Consequently, the simple

  14. Vortex-induced vibrations of a flexibly-mounted inclined cylinder

    NASA Astrophysics Data System (ADS)

    Jain, Anil; Modarres-Sadeghi, Yahya

    2013-11-01

    The majority of studies on vortex-induced vibrations of a flexibly-mounted rigid cylinder are for the cases where the flow direction is perpendicular to the long axis of the structure. However, in many engineering applications, such as cable stays in bridges and mooring lines of floating offshore wind turbines, the flow direction may not be perpendicular to the structure. To understand the vortex shedding behind a fixed inclined cylinder, the Independence Principle (IP) has been used. The IP assumes that an inclined cylinder behaves similarly to a normal-incidence case, if only the component of the free stream velocity normal to the cylinder axis is considered. The IP neglects the effect of the axial component of the flow, which seems reasonable for small angles of inclination, but not for large angles. In the present study, a series of experiments have been conducted on a flexibly-mounted rigid cylinder placed inclined to the oncoming flow with various angles of inclination (0°<θ<75°) in a range of Reynolds numbers from 500 to 4000 to investigate how the angle of inclination affects VIV. A rigid cylinder was mounted on springs, and air bearings were used to reduce the structural damping of the system. The system was placed in the test-section of a recirculating water tunnel and the crossflow displacements were measured at each flow velocity. Even at high angles of inclination, large-amplitude oscillations were observed. As the angle of inclination was increased, the lock-in range (the range of reduced flow velocities for which the cylinder oscillates with a large amplitude) started at a higher reduced velocity. When only the normal component of the oncoming flow was considered, the onset of lock-in was observed to be at the same normalized flow velocity for all angles of inclination except for 75°. However, the width of the lock-in region, its pattern, the maximum amplitude of oscillations and its corresponding normalized reduced velocity were not following

  15. Cylinder-temperature correlation of a single-cylinder liquid-cooled engine

    NASA Technical Reports Server (NTRS)

    Pinkel, Benjamin; Manganiello, Eugene J; Bernardo, Everett

    1946-01-01

    An analysis based on nonboiling forced-convection heat-transfer theory is made of the cooling processes in liquid-cooled engine cylinders. Semiempirical equations that relate the average head and barrel temperatures with the primary engine and coolant parameters are derived. A correlation method based on these equations is applied to data obtained from previously reported investigations, which were conducted over large ranges of engine and coolant conditions with two liquid-cooled cylinders using water and various aqueous ethylene glycol solutions as coolants. Upon evaluation of empirical factors, an equation for the cylinder-head temperature as a function of the engine operating conditions and the flow rate, temperature, and physical properties of the coolants is obtained, which represents the data with good accuracy.

  16. CNG Cylinder Safety - Education, Outreach, and Next Steps (Presentation)

    SciTech Connect

    Smith, M.; Schroeder, A.

    2014-01-01

    Mr. Schroeder discussed the work that NREL is performing for the U.S. Department of Transportation on compressed natural gas cylinder end-of-life requirements. CNG vehicles are different from most other vehicles in that the CNG fuel storage cylinders have a pre-determined lifetime that may be shorter than the expected life of the vehicle. The end-of-life date for a cylinder is based on construction and test protocols, and is specific to the construction and material of each cylinder. The end-of-life date is important because it provides a safe margin of error against catastrophic cylinder failure or rupture. The end-of-life dates range from 15 to 25 years from the date of manufacture. NREL worked to develop outreach materials to increase awareness of cylinder end-of-life dates, has provided technical support for individual efforts related to cylinder safety and removal, and also worked with CVEF to document best practices for cylinder removal or inspection after an accident. Mr. Smith discussed the engagement of the DOE Clean Fleets Partners, which were surveyed to identify best practices on managing cylinder inventories and approached to provide initial data on cylinder age in a fleet environment. Both DOE and NREL will continue to engage these fleets and other stakeholders to determine how to best address this issue moving forward.

  17. Measurements of the Flowfield Interaction Between Tandem Cylinders

    NASA Technical Reports Server (NTRS)

    Neuhart, Dan H.; Jenkins, Luther N.; Choudhari, Meelan M.; Khorrami, Mehdi R.

    2009-01-01

    This paper presents the most recent measurements from an ongoing investigation of the unsteady wake interference between a pair of circular cylinders in tandem. The purpose of this investigation is to help build an in-depth experimental database for this canonical flow configuration that embodies the effects of component interaction in landing gear noise. This new set of measurements augments the previous database at the primary Reynolds number (based on tunnel speed and cylinder diameter) of 1.66 105 in four important respects. First, better circumferential resolution of surface pressure fluctuations is obtained via cylinder "clocking". Second, higher resolution particle image velocimetry measurements of the shear layer separating from the cylinders are achieved. Third, the effects of simultaneous boundary layer trips along both the front and rear cylinders, versus front cylinder alone in the previous measurements, are studied. Lastly, on-surface and off-surface characteristics of unsteady flow near the "critical" cylinder spacing, wherein the flow switches intermittently between two states that are characteristic of lower and higher spacings, are examined. This critical spacing occurs in the middle of a relatively sudden change in the drag of either cylinder and is characterized by a loud intermittent noise and a flow behavior that randomly transitions between shear layer attachment to the rear cylinder and constant shedding and rollup in front of it. Analysis of this bistable flow state reveals much larger spanwise correlation lengths of surface pressure fluctuations than those at larger and smaller values of the cylinder spacing.

  18. Effect of hole geometry and Electric-Discharge Machining (EDM) on airflow rates through small diameter holes in turbine blade material

    NASA Technical Reports Server (NTRS)

    Hippensteele, S. A.; Cochran, R. P.

    1980-01-01

    The effects of two design parameters, electrode diameter and hole angle, and two machine parameters, electrode current and current-on time, on air flow rates through small-diameter (0.257 to 0.462 mm) electric-discharge-machined holes were measured. The holes were machined individually in rows of 14 each through 1.6 mm thick IN-100 strips. The data showed linear increase in air flow rate with increases in electrode cross sectional area and current-on time and little change with changes in hole angle and electrode current. The average flow-rate deviation (from the mean flow rate for a given row) decreased linearly with electrode diameter and increased with hole angle. Burn time and finished hole diameter were also measured.

  19. Magnetic neutron scattering by magnetic vortices in thin submicron-sized soft ferromagnetic cylinders

    NASA Astrophysics Data System (ADS)

    Metlov, Konstantin L.; Michels, Andreas

    2016-04-01

    Using analytical expressions for the magnetization textures of thin submicron-sized magnetic cylinders in vortex state, we derive closed-form algebraic expressions for the ensuing small-angle neutron scattering (SANS) cross sections. Specifically, for the perpendicular and parallel scattering geometries, we have computed the cross sections for the case of small vortex-center displacements without formation of magnetic charges on the side faces of the cylinder. The results represent a significant qualitative and quantitative step forward in SANS-data analysis on isolated magnetic nanoparticle systems, which are commonly assumed to be homogeneously or stepwise-homogeneously magnetized. We suggest a way to extract the fine details of the magnetic vortex structure during the magnetization process from the SANS measurements in order to help resolving the long-standing question of the magnetic vortex displacement mode.

  20. Magnetic neutron scattering by magnetic vortices in thin submicron-sized soft ferromagnetic cylinders

    PubMed Central

    Metlov, Konstantin L.; Michels, Andreas

    2016-01-01

    Using analytical expressions for the magnetization textures of thin submicron-sized magnetic cylinders in vortex state, we derive closed-form algebraic expressions for the ensuing small-angle neutron scattering (SANS) cross sections. Specifically, for the perpendicular and parallel scattering geometries, we have computed the cross sections for the case of small vortex-center displacements without formation of magnetic charges on the side faces of the cylinder. The results represent a significant qualitative and quantitative step forward in SANS-data analysis on isolated magnetic nanoparticle systems, which are commonly assumed to be homogeneously or stepwise-homogeneously magnetized. We suggest a way to extract the fine details of the magnetic vortex structure during the magnetization process from the SANS measurements in order to help resolving the long-standing question of the magnetic vortex displacement mode. PMID:27112640

  1. Modeling of Cylindrical Couette Flow of Rarefied Gas. The Case of Rotating Outer Cylinder

    SciTech Connect

    Gospodinov, P.; Dankov, D.; Roussinov, V.; Stefanov, S.

    2009-10-29

    The cylindrical Couette flow of a rarefied gas is studied in the case when the outer cylinder is rotating while the inner cylinder is at rest. Velocity, density and temperature profiles are investigated by a Direct Monte Carlo Simulation method and a numerical solution of the Navier-Stokes equations for compressible flow is found. The results obtained by both methods are: in an excellent agreement at a small Knudsen number Kn = 0.02; in a satisfactory agreement at Kn = 0.1 and they vastly differs each other at a moderate Kn = 0.5. The comparison shows that the continuum approach can be used successfully for calculations of non-planar isothermal rarefied gas flows at small Knudsen numbers Kn<0.1. These results are important for applications in non-planar microfluidic problems.

  2. The marginalization of "small is beautiful": Micro-hydroelectricity, common property, and the politics of rural electricity provision in Thailand

    NASA Astrophysics Data System (ADS)

    Greacen, Christopher Edmund

    electricity to PEA offers a mutually beneficial opportunity for the Thai public and for villagers, but one thus far thwarted by bureaucratic challenges. Explanations of renewable energy dissemination in countries with strong state involvement in rural electrification should borrow approaches from political economy concerning the ways in which politics and constellations of other factors eclipse rational economic behavior. At the village level, common pool resource theory reveals causal linkages between appliance use, equipment limitations, power quality, and equipment failures.

  3. Turbulent boundary layers along straight and curved long thin circular cylinders at low angles-of-incidence

    NASA Astrophysics Data System (ADS)

    Jordan, Stephen A.

    2016-05-01

    Long thin circular cylinders commonly serve as towed sonar tracking devices, where the radius-of-curvature along the longitudinal axis is quite low [ρr = O(10-4)]. Because no understanding presently exists about the direct impact of longitudinal curvature on the turbulent statistics, the long cylinder is simply viewed as a chain of straight segments at various (increasing then decreasing) small inclinations to the freestream direction. Realistically, even our statistical evidence along straight thin cylinders at low incidence angles is inadequate to build solid evidence towards forming reliable empirical models. In the present study, we address these shortcomings by executing Large-Eddy Simulations (LESs) of straight and longitudinally curved thin cylinders at low to moderate turbulent radius-based Reynolds numbers (500 ≤ Rea ≤ 3500) and small angles-of-incidence (α = 0° → 9°). Coupled with the previous experimental measurements and numerical results, the new expanded database (311 ≤ Rea ≤ 56 500) delivered sufficient means to propose power-law expressions for the longitudinal evolution of the skin friction, normal drag, and turbulent boundary layer (TBL) length scales. Surprisingly, the LES computations of the curved cylinders at analogous geometric and kinematic conditions as the straight cylinder showed similar character in terms of the longitudinal skin friction. Beyond incidence 1°-3° (upper end corresponds to the highest simulated Rea), the skin friction was directly proportional to the yaw angle and monotonically shifted downward with higher Rea. Conversely, the flow structure, normal drag, TBL length scales, Reynolds stresses, and the separation state of the transverse shear layers towards regular vortex shedding for the curved cylinder were highly dissimilar than the straight one at equivalent incidence angles.

  4. Generalized thick strip modelling for vortex-induced vibration of long flexible cylinders

    NASA Astrophysics Data System (ADS)

    Bao, Y.; Palacios, R.; Graham, M.; Sherwin, S.

    2016-09-01

    We propose a generalized strip modelling method that is computationally efficient for the VIV prediction of long flexible cylinders in three-dimensional incompressible flow. In order to overcome the shortcomings of conventional strip-theory-based 2D models, the fluid domain is divided into "thick" strips, which are sufficiently thick to locally resolve the small scale turbulence effects and three dimensionality of the flow around the cylinder. An attractive feature of the model is that we independently construct a three-dimensional scale resolving model for individual strips, which have local spanwise scale along the cylinder's axial direction and are only coupled through the structural model of the cylinder. Therefore, this approach is able to cover the full spectrum for fully resolved 3D modelling to 2D strip theory. The connection between these strips is achieved through the calculation of a tensioned beam equation, which is used to represent the dynamics of the flexible body. In the limit, however, a single "thick" strip would fill the full 3D domain. A parallel Fourier spectral/hp element method is employed to solve the 3D flow dynamics in the strip-domain, and then the VIV response prediction is achieved through the strip-structure interactions. Numerical tests on both laminar and turbulent flows as well as the comparison against the fully resolved DNS are presented to demonstrate the applicability of this approach.

  5. a Numerical Study of Cylinders in Waves and Currents

    NASA Astrophysics Data System (ADS)

    Zhou, C. Y.; Graham, J. M. R.

    2000-04-01

    The research on combination flow of planar oscillatory flow plus an in-line steady stream is of importance to the situation of structures in waves and current. The combination flow has not been studied extensively. There is still little information about the effect of current and about combined effect of current and waves on hydrodynamic loading of the structures. The present study investigates the combination flow around a circular cylinder using a vortex-based method incorporating vortex moving particles (discrete vortices) with a finite-difference scheme for the vorticity diffusion. The main attention is paid to the effects of a small current on in-line fluid forces and vortex patterns in the wake. Morison's equation and an equation with two drag terms are examined. The results show that the presence of a small current in an oscillatory flow can reduce the drag coefficient significantly. Morison's equation gives reasonably good predictions for the in-line forces for an oscillatory flow plus a small current. The current tends to bring the whole vortex wake downstream and tries to form the stable Karman asymmetrical form in the downstream wake. The present results show certain agreement with some previous experimental results.

  6. The Modeling of Flow Around a Cylinder and Scour Hole

    NASA Astrophysics Data System (ADS)

    Smith, H. D.; Foster, D. L.

    2001-12-01

    The scouring of an erodible bed around a submarine object is a concern for hydraulic and coastal scientists. Our ability to model this process depends on how well we can resolve not only the flow around the obstacle, but the physics of sediment transport. As a first step in addressing this complicated problem, we are performing model-data comparisons of flow around a pipeline during five stages of the scour hole development. Currently, we are using the computational fluid dynamics (CFD) model, FLOW-3D, to simulate the velocity profiles around the pipeline and the scour hole. FLOW-3D has the option of five turbulence models (1-equation turbulent energy, 2-equation k-e, Renormalization-Group, Large Eddy Simulation, and Prandtl Mixing Length), resolves fluid-fluid and fluid-air interfaces, and has variable time steps to assure model stability. The model simulations are modeled after and then compared with laboratory investigations by B.L. Jensen et. al. in 1990 (Journal of Offshore Mechanics and Artic Engineering. Volume 112, pgs. 206-216). In the laboratory experiment, all surfaces were hydraulically smooth, however, adding a small roughness (0.5 mm) to the model was found to give improved correlations. The k-e model shows the highest model-data correlations and the lowest RMS deviations for both horizontal mean velocity and turbulent kinetic energy. Vertical mean velocity values are comparable between the different turbulence models. Model-data comparisons are made for the horizontal and vertical mean velocity profiles, as well as the turbulent kinetic energy profiles at several locations upstream and downstream of the cylinder. Model results are in general good agreement with R-squared correlations as high as 1.0 and RMS deviations as low as 0.24 cm/s. However, the poorest correlations are found in the estimations of the turbulent kinetic energy. The presence of the pipeline results in a 1.4 fold increase in the boundary layer eight cylinder diameters downstream

  7. Acoustics and Surface Pressure Measurements from Tandem Cylinder Configurations

    NASA Technical Reports Server (NTRS)

    Hutcheson, Florence V.; Brooks, Thomas F.; Lockard, David P.; Choudhari, Meelan M.; Stead, Daniel J.

    2014-01-01

    Acoustic and unsteady surface pressure measurements from two cylinders in tandem configurations were acquired to study the effect of spacing, surface trip and freestream velocity on the radiated noise. The Reynolds number ranged from 1.15x10(exp 5) to 2.17x10(exp 5), and the cylinder spacing varied between 1.435 and 3.7 cylinder diameters. The acoustic and surface pressure spectral characteristics associated with the different flow regimes produced by the cylinders' wake interference were identified. The dependence of the Strouhal number, peak Sound Pressure Level and spanwise coherence on cylinder spacing and flow velocity was examined. Directivity measurements were performed to determine how well the dipole assumption for the radiation of vortex shedding noise holds for the largest and smallest cylinder spacing tested.

  8. Numerical investigation of the cylinder movement in granular matter.

    PubMed

    Zhang, Xue; Sheng, Daichao; Kouretzis, George P; Krabbenhoft, Kristian; Sloan, Scott W

    2015-02-01

    We investigate numerically the mechanisms governing horizontal dragging of a rigid cylinder buried inside granular matter, with particular emphasis on enumerating drag and lift forces that resist cylinder movement. The recently proposed particle finite element method is employed, which combines the robustness of classical continuum mechanics formulations in terms of representing complex aspects of the material constitutive behavior, with the effectiveness of discrete element methods in simulating ultralarge deformation problems. The investigation focuses on the effect of embedment depth, cylinder roughness, granular matter macromechanical properties, and of the magnitude of the cylinder's horizontal displacement on the amplitude of the resisting forces, which are discussed in light of published experimental data. Interpretation of the results provides insight on how the material flow around the cylinder affects the developing resistance, and a mechanism is proposed to describe the development of a steady-state drag force at large horizontal movements of the cylinder. PMID:25768495

  9. High-frequency backscatter from a finned cylinder at grazing incidence - Comparison of two theoretical methods

    NASA Astrophysics Data System (ADS)

    Michaeli, A.

    1986-02-01

    A closed-form, high-frequency approximation is obtained for the diffracted-reflected-diffracted field contribution to the backscattered field resulting from the grazing illumination of a perfectly conducting, infinitely long, finned cylinder by a normally incident cylindrical transverse magnetic (TM) wave. The result, which is valid for any relative magnitudes of the cylinder radius and the fin width provided both of them are electrically large, is derived by two different methods. One of them is the radiation integral method related to the physical theory of diffraction. The other is the complex ray tracing method related to the spectral theory of diffraction (STD). Relative merits and disadvantages of the two methods are pointed out.

  10. Reaction formulation for radiation and scattering from plates, corner reflectors and dielectric-coated cylinders

    NASA Technical Reports Server (NTRS)

    Wang, N. N.

    1974-01-01

    The reaction concept is employed to formulate an integral equation for radiation and scattering from plates, corner reflectors, and dielectric-coated conducting cylinders. The surface-current density on the conducting surface is expanded with subsectional bases. The dielectric layer is modeled with polarization currents radiating in free space. Maxwell's equation and the boundary conditions are employed to express the polarization-current distribution in terms of the surface-current density on the conducting surface. By enforcing reaction tests with an array of electric test sources, the moment method is employed to reduce the integral equation to a matrix equation. Inversion of the matrix equation yields the current distribution, and the scattered field is then obtained by integrating the current distribution. The theory, computer program and numerical results are presented for radiation and scattering from plates, corner reflectors, and dielectric-coated conducting cylinders.

  11. A methodology for combustion detection in diesel engines through in-cylinder pressure derivative signal

    NASA Astrophysics Data System (ADS)

    Luján, José M.; Bermúdez, Vicente; Guardiola, Carlos; Abbad, Ali

    2010-10-01

    In-cylinder pressure measurement has historically been used for off-line combustion diagnosis, but online application for real-time combustion control has become of great interest. This work considers low computing-cost methods for analysing the instant variation of the chamber pressure, directly obtained from the electric signal provided by a traditional piezoelectric sensor. Presented methods are based on the detection of sudden changes in the chamber pressure, which are amplified by the pressure derivative, and which are due to thermodynamic phenomena within the cylinder. Signal analysis tools both in time and in time-frequency domains are used for detecting the start of combustion, the end of combustion and the heat release peak. Results are compared with classical thermodynamic analysis and validated in several turbocharged diesel engines.

  12. Cylinder yard inspections and corrective actions

    SciTech Connect

    Barlow, C.R. ); Ziehlke, K.T. ); Pryor, W.A. )

    1990-07-31

    Inspection of valves on stored uranium hexafluoride (UF{sub 6}) cylinders was initiated at the three diffusion plant sites in Oak Ridge, Tennessee, Paducah, Kentucky, and Portsmouth, Ohio as the result of the discovery of valve defects and evidence of valve leaks at the Oak Ridge K-25 plant. The coordinated inspection culminated in the identification of additional factors related to long-term safe storage of UF{sub 6}, and plans for correction of such deficiencies are presently being developed and implemented. These corrective actions supplement existing programs aimed at assurance of safe storage as summarized in the report.

  13. Coalescence of two viscous cylinders by capillarity

    SciTech Connect

    Hopper, R.W. )

    1993-12-01

    The creeping plane flow of two viscous cylinders coalescing under the influence of surface tension is described theoretically in a series of three articles. Part I is a theoretical overview. The physical assumptions affecting applicability of the theory are discussed. The shape as a function of time and of the initial diameter ratio D [>=] 1 is given in parametric form. For D = 1 and D = [infinity], the shape sequences are known exactly; for finite D > 1, a first-order differential equation is solved numerically. The time requires a quadrature. This is accurate, and easier than solving the fluid-dynamical field equations. The theory encompasses time-dependent liquid properties.

  14. Mounting with compliant cylinders for deformable mirrors.

    PubMed

    Reinlein, Claudia; Goy, Matthias; Lange, Nicolas; Appelfelder, Michael

    2015-04-01

    A method is presented to mount large aperture unimorph deformable mirrors by compliant cylinders (CC). The CCs are manufactured from a soft silicone, and shear testing is performed in order to evaluate the Young's modulus. A scale mirror model is assembled to evaluate mount-induced change of piezoelectric deformation, and its applicability for tightly focusing mirrors. Experiments do not show any decrease of piezoelectric stroke. Further it is shown that the changes of surface fidelity by the attachment of the deformable mirror to its mount are neglectable.

  15. A model of filament-wound thin cylinders

    NASA Technical Reports Server (NTRS)

    Calius, Emilio P.; Springer, George S.

    1990-01-01

    A model was developed for simulating he manufacturing process of filament-wound cylinders made of a thermoset matrix composite. The model relates the process variables (winding speed, fiber tension, applied temperature) to the parameters characterizing the composite cylinder and the mandrel. The model is applicable to cylinders for which the diameter is large compared to the wall thickness. The model was implemented by a user-friendly computer code suitable for generating numerical results.

  16. Ionic wind generation by a wire-cylinder-plate corona discharge in air at atmospheric pressure

    NASA Astrophysics Data System (ADS)

    Colas, Dorian F.; Ferret, Antoine; Pai, David Z.; Lacoste, Deanna A.; Laux, Christophe O.

    2010-11-01

    A wire-cylinder-plate electrode configuration is presented to generate ionic wind with a dc corona discharge in air at atmospheric pressure. The objective of the work is to maximize the power supplied to the flow in order to increase acceleration while avoiding breakdown. Thus, the proposed experimental setup addresses the problem of decoupling the mechanism of ion generation from that of ion acceleration. Using a wire-plate configuration as a reference, we have focused on improving the topography of the electric field to (1) separate the ionization and acceleration zones in space, and (2) guide the trajectory of charged particles as parallel to the median axis as possible. In the proposed wire-cylinder-plate setup, a dc corona discharge is generated in the space between a wire and two cylinders. The ions produced by the corona then drift past the cylinders and into a channel between two plates, where they undergo acceleration. To maximize the ionic wind it is found that the geometric configuration must be as compact as possible and that the voltage applied must be right below breakdown. Experimentally, the optimized wire-plate reference setup provides a maximum flow velocity of 8 m s-1, a flow rate per unit electrode length of 0.034 m2 s-1, and a thrust per unit electrode length of 0.24 N m-1. The wire-cylinder-plate configuration provides a maximum flow velocity of 10 m s-1, a flow rate per unit electrode length of 0.041 m2 s-1, and a thrust per unit electrode length of 0.35 N m-1. This 46% increase in thrust is obtained by increasing the electric power per unit electrode length by only 16% (from 175 to 210 W m-1), which confirms the gain in efficiency obtained with the decoupled system. In comparison with a simple wire-wire corona configuration, the wire-cylinder-plate configuration increases the ionic wind velocity by up to a factor of 3, and the thrust by an order of magnitude.

  17. Electric vehicles

    SciTech Connect

    Not Available

    1990-03-01

    Quiet, clean, and efficient, electric vehicles (EVs) may someday become a practical mode of transportation for the general public. Electric vehicles can provide many advantages for the nation's environment and energy supply because they run on electricity, which can be produced from many sources of energy such as coal, natural gas, uranium, and hydropower. These vehicles offer fuel versatility to the transportation sector, which depends almost solely on oil for its energy needs. Electric vehicles are any mode of transportation operated by a motor that receives electricity from a battery or fuel cell. EVs come in all shapes and sizes and may be used for different tasks. Some EVs are small and simple, such as golf carts and electric wheel chairs. Others are larger and more complex, such as automobile and vans. Some EVs, such as fork lifts, are used in industries. In this fact sheet, we will discuss mostly automobiles and vans. There are also variations on electric vehicles, such as hybrid vehicles and solar-powered vehicles. Hybrid vehicles use electricity as their primary source of energy, however, they also use a backup source of energy, such as gasoline, methanol or ethanol. Solar-powered vehicles are electric vehicles that use photovoltaic cells (cells that convert solar energy to electricity) rather than utility-supplied electricity to recharge the batteries. This paper discusses these concepts.

  18. Coupled Thermo-Mechanical Analyses of Dynamically Loaded Rubber Cylinders

    NASA Technical Reports Server (NTRS)

    Johnson, Arthur R.; Chen, Tzi-Kang

    2000-01-01

    A procedure that models coupled thermo-mechanical deformations of viscoelastic rubber cylinders by employing the ABAQUS finite element code is described. Computational simulations of hysteretic heating are presented for several tall and short rubber cylinders both with and without a steel disk at their centers. The cylinders are compressed axially and are then cyclically loaded about the compressed state. The non-uniform hysteretic heating of the rubber cylinders containing a steel disk is presented. The analyses performed suggest that the coupling procedure should be considered for further development as a design tool for rubber degradation studies.

  19. Enrichment Assay Methods Development for the Integrated Cylinder Verification System

    SciTech Connect

    Smith, Leon E.; Misner, Alex C.; Hatchell, Brian K.; Curtis, Michael M.

    2009-10-22

    International Atomic Energy Agency (IAEA) inspectors currently perform periodic inspections at uranium enrichment plants to verify UF6 cylinder enrichment declarations. Measurements are typically performed with handheld high-resolution sensors on a sampling of cylinders taken to be representative of the facility's entire product-cylinder inventory. Pacific Northwest National Laboratory (PNNL) is developing a concept to automate the verification of enrichment plant cylinders to enable 100 percent product-cylinder verification and potentially, mass-balance calculations on the facility as a whole (by also measuring feed and tails cylinders). The Integrated Cylinder Verification System (ICVS) could be located at key measurement points to positively identify each cylinder, measure its mass and enrichment, store the collected data in a secure database, and maintain continuity of knowledge on measured cylinders until IAEA inspector arrival. The three main objectives of this FY09 project are summarized here and described in more detail in the report: (1) Develop a preliminary design for a prototype NDA system, (2) Refine PNNL's MCNP models of the NDA system, and (3) Procure and test key pulse-processing components. Progress against these tasks to date, and next steps, are discussed.

  20. An update on corrosion monitoring in cylinder storage yards

    SciTech Connect

    Henson, H.M.; Newman, V.S.; Frazier, J.L.

    1991-12-31

    Depleted uranium, from US uranium isotope enrichment activities, is stored in the form of solid uranium hexafluoride (UF{sub 6}) in A285 and A516 steel cylinders designed and manufactured to ASME Boiler and Pressure Vessel Code criteria. In general, storage facilities are open areas adjacent to the enrichment plants where the cylinders are exposed to weather. This paper describes the Oak Ridge program to determine the general corrosion behavior of UF{sub 6} cylinders, to determine cylinder yard conditions which are likely to affect long term storage of this material, and to assess cylinder storage yards against these criteria. This program is targeted at conditions specific to the Oak Ridge cylinder yards. Based on (a) determination of the current cylinder yard conditions, (b) determination of rusting behavior in regions of the cylinders showing accelerated attack, (c) monitoring of corrosion rates through periodic measurement of test coupons placed within the cylinder yards, and (d) establishment of a computer base to incorporate and retain these data, the technical division is working with the enrichment sites to implement an upgraded system for storage of this material until such time as it is used or converted.

  1. Global existence and exponential stability of solutions in H for the compressible Navier-Stokes equations with the cylinder symmetry

    NASA Astrophysics Data System (ADS)

    Qin, Yuming; Jiang, Limin

    This paper is concerned with the global existence and exponential stability of solutions in H for the compressible Navier-Stokes equations with the cylinder symmetry in R when the initial total energy is sufficiently small. Moreover, the global existence and exponential stability of the classical solution can be also derived.

  2. Near-wake flow structure of elliptic cylinders close to a free surface: effect of cylinder aspect ratio

    NASA Astrophysics Data System (ADS)

    Daichin, K. V.; Lee, Sang Joon

    The flow fields behind elliptic cylinders adjacent to a free surface were investigated experimentally in a circulating water channel. A range of cylinder aspect ratios (AR=2, 3, 4) were considered, while the cross-sectional area of the elliptical cylinder was kept constant. The main objective of this study was to investigate the effect of cylinder aspect ratio and a free surface on the flow structure in the near-wake behind elliptic cylinders. For each elliptic cylinder, the flow structure was analyzed for various values of the submergence depth of the cylinder beneath the free surface. The flow fields were measured using a single-frame double-exposure PIV (Particle Image Velocimetry) system. For each experimental condition, 350 instantaneous velocity fields were obtained and ensemble-averaged to obtain the mean velocity field and spatial distribution of the mean vorticity statistics. The results show that near-wake can be classified into three typical flow patterns: formation of a Coanda flow, generation of substantial jet-like flow, and attachment of this jet flow to the free surface. The general flow structure observed behind the elliptic cylinders resembles the structure previously reported for a circular cylinder submerged near a free surface. However, the wake width and the angle of downward deflection of the shear layer developed from the lower surface of the elliptic cylinder differ from those observed for a circular cylinder. These trends are enhanced as cylinder aspect ratio is increased. In addition, the free surface distortion is also discussed in the paper.

  3. EC Driver - 41" Stroke Hydraulic Cylinder

    SciTech Connect

    Jaques, A.; /Fermilab

    1990-05-24

    It was decided to use a hydraulic cylinder resting on the floor of the argon spill trough in the EC carriage to drive the EC's motion on the center beam. Space was limited due to the spill bellows and their required support and containment system. The 0.0. of the cylinder had to be limited to 3 to 3-1/2 inches, maximum. The weight of a wet EC and carriage is estimated to be 320 tons. The rolling coefficient of friction of the Tychoway rollers chosen to guide the EC and carriage along the hardened centerbeam ways is claimed to be less than 0.0025. The driver will also need to overcome the forces produced by moving (rotating) the numerous bayonets located at the top of the cryostats in the many piping systems. These forces were conservatively estimated at 1000 lbs. The drive force required to overcome these forces was then calculated to be: 320(2,000) x 0.0025 + 1,000 = 2.600 lbs. (min. required). Due to the uncertainty in the actual roller coefficient of friction and the various unknowns in estimating the resistive forces contained in the piping and cabling systems attached to the cryostat, a conservative design factor of 5 was chosen. This should account for any uncertainty in our estimation of the minimum required drive force and also leaves us with a reserve to fall back on in case any unforeseen problems might arise. Thus the desired capacity of the driver was set at: (2,600) x 5 = 13,000 lbs. (design capacity). Assuming a 3 inch O.D. cylinder with a 1/2 inch wall (2 inch bore), we first analyzed a 1-3/8 inch diameter piston rod. Using Shigley & Mischke's 'Mechanical Engineering Design' (5th Ed.) and it's formulas for long columns with central loading, it was determined that a 1-3/8 inch diameter rod would not suffice, given our safety factor of 2. Increasing the piston rod diameter to 1-1/2 inches proved to be sufficient. The maximum allowable load came out to be approximately 17,000 lbs., which is greater than the 13,000 lbs. design capacity. With a 1-1/2 inch

  4. CYLINDER LENS ALIGNMENT IN THE LTP

    SciTech Connect

    TAKACS, P.Z.

    2005-07-26

    The Long Trace Profiler (LTP), is well-suited for the measurement of the axial figure of cylindrical mirrors that usually have a long radius of curvature in the axial direction but have a short radius of curvature in the sagittal direction. The sagittal curvature causes the probe beam to diverge in the transverse direction without coming to a focus on the detector, resulting in a very weak signal. It is useful to place a cylinder lens into the optical system above the mirror under test to refocus the sagittal divergence and increase the signal level. A positive cylinder lens can be placed at two positions above the surface: the Cat's Eye reflection position and the Wavefront-Matching position. The Cat's Eye position, is very tolerant to mirror misalignment, which is not good if absolute axial radius of curvature is to be measured. Lateral positioning and rotational misalignments of lens and the mirror combine to produce unusual profile results. This paper looks at various alignment issues with measurements and by raytrace simulations to determine the best strategy to minimize radius of curvature errors in the measurement of cylindrical aspheres.

  5. Support arrangement for optimizing a low pressure steam turbine inner cylinder structural performance

    SciTech Connect

    Groenendaal, J.C. Jr.; Anemone, J.J.

    1992-07-28

    This patent describes low pressure steam turbine apparatus having inner and outer cylinders, the outer cylinder having a support shelf, and inner cylinder support means for providing flexible support of the inner cylinder on the outer cylinder. It comprises: a horizontal joint flange and at least one support foot integrally connected thereto which projects substantially radially outward form the horizontal joint flange.

  6. 49 CFR 178.39 - Specification 3BN seamless nickel cylinders.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 3 2012-10-01 2012-10-01 false Specification 3BN seamless nickel cylinders. 178... FOR PACKAGINGS Specifications for Cylinders § 178.39 Specification 3BN seamless nickel cylinders. (a) Type, size and service pressure. A DOT 3BN cylinder is a seamless nickel cylinder with a water...

  7. 49 CFR 178.39 - Specification 3BN seamless nickel cylinders.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Specification 3BN seamless nickel cylinders. 178... FOR PACKAGINGS Specifications for Cylinders § 178.39 Specification 3BN seamless nickel cylinders. (a) Type, size and service pressure. A DOT 3BN cylinder is a seamless nickel cylinder with a water...

  8. 49 CFR 178.39 - Specification 3BN seamless nickel cylinders.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 3 2013-10-01 2013-10-01 false Specification 3BN seamless nickel cylinders. 178... FOR PACKAGINGS Specifications for Cylinders § 178.39 Specification 3BN seamless nickel cylinders. (a) Type, size and service pressure. A DOT 3BN cylinder is a seamless nickel cylinder with a water...

  9. 49 CFR 178.39 - Specification 3BN seamless nickel cylinders.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 3 2014-10-01 2014-10-01 false Specification 3BN seamless nickel cylinders. 178... FOR PACKAGINGS Specifications for Cylinders § 178.39 Specification 3BN seamless nickel cylinders. (a) Type, size and service pressure. A DOT 3BN cylinder is a seamless nickel cylinder with a water...

  10. 49 CFR 178.39 - Specification 3BN seamless nickel cylinders.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 3 2011-10-01 2011-10-01 false Specification 3BN seamless nickel cylinders. 178... FOR PACKAGINGS Specifications for Cylinders § 178.39 Specification 3BN seamless nickel cylinders. (a) Type, size and service pressure. A DOT 3BN cylinder is a seamless nickel cylinder with a water...

  11. 49 CFR 178.68 - Specification 4E welded aluminum cylinders.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Specification 4E welded aluminum cylinders. 178.68... FOR PACKAGINGS Specifications for Cylinders § 178.68 Specification 4E welded aluminum cylinders. (a) Type, size and service pressure. A DOT 4E cylinder is a welded aluminum cylinder with a water...

  12. 49 CFR 178.68 - Specification 4E welded aluminum cylinders.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 3 2012-10-01 2012-10-01 false Specification 4E welded aluminum cylinders. 178.68... PACKAGINGS Specifications for Cylinders § 178.68 Specification 4E welded aluminum cylinders. (a) Type, size and service pressure. A DOT 4E cylinder is a welded aluminum cylinder with a water capacity...

  13. 49 CFR 178.46 - Specification 3AL seamless aluminum cylinders.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 3 2012-10-01 2012-10-01 false Specification 3AL seamless aluminum cylinders. 178... FOR PACKAGINGS Specifications for Cylinders § 178.46 Specification 3AL seamless aluminum cylinders. (a) Size and service pressure. A DOT 3AL cylinder is a seamless aluminum cylinder with a maximum...

  14. 49 CFR 178.68 - Specification 4E welded aluminum cylinders.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 3 2013-10-01 2013-10-01 false Specification 4E welded aluminum cylinders. 178.68... PACKAGINGS Specifications for Cylinders § 178.68 Specification 4E welded aluminum cylinders. (a) Type, size and service pressure. A DOT 4E cylinder is a welded aluminum cylinder with a water capacity...

  15. 49 CFR 178.46 - Specification 3AL seamless aluminum cylinders.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 3 2013-10-01 2013-10-01 false Specification 3AL seamless aluminum cylinders. 178... FOR PACKAGINGS Specifications for Cylinders § 178.46 Specification 3AL seamless aluminum cylinders. (a) Size and service pressure. A DOT 3AL cylinder is a seamless aluminum cylinder with a maximum...

  16. 49 CFR 178.68 - Specification 4E welded aluminum cylinders.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 3 2014-10-01 2014-10-01 false Specification 4E welded aluminum cylinders. 178.68... PACKAGINGS Specifications for Cylinders § 178.68 Specification 4E welded aluminum cylinders. (a) Type, size and service pressure. A DOT 4E cylinder is a welded aluminum cylinder with a water capacity...

  17. 49 CFR 178.68 - Specification 4E welded aluminum cylinders.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 3 2011-10-01 2011-10-01 false Specification 4E welded aluminum cylinders. 178.68... PACKAGINGS Specifications for Cylinders § 178.68 Specification 4E welded aluminum cylinders. (a) Type, size and service pressure. A DOT 4E cylinder is a welded aluminum cylinder with a water capacity...

  18. 49 CFR 178.46 - Specification 3AL seamless aluminum cylinders.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 3 2011-10-01 2011-10-01 false Specification 3AL seamless aluminum cylinders. 178... FOR PACKAGINGS Specifications for Cylinders § 178.46 Specification 3AL seamless aluminum cylinders. (a) Size and service pressure. A DOT 3AL cylinder is a seamless aluminum cylinder with a maximum...

  19. 49 CFR 178.46 - Specification 3AL seamless aluminum cylinders.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 3 2014-10-01 2014-10-01 false Specification 3AL seamless aluminum cylinders. 178... FOR PACKAGINGS Specifications for Cylinders § 178.46 Specification 3AL seamless aluminum cylinders. (a) Size and service pressure. A DOT 3AL cylinder is a seamless aluminum cylinder with a maximum...

  20. Stress and reliability analyses of multilayered composite cylinder under thermal and mechanical loads

    NASA Astrophysics Data System (ADS)

    Wang, Xiaohua

    The coupling resulting from the mutual influence of material thermal and mechanical parameters is examined in the thermal stress analysis of a multilayered isotropic composite cylinder subjected to sudden axisymmetric external and internal temperature. The method of complex frequency response functions together with the Fourier transform technique is utilized. Because the coupling parameters for some composite materials, such as carbon-carbon, are very small, the effect of coupling is neglected in the orthotropic thermal stress analysis. The stress distributions in multilayered orthotropic cylinders subjected to sudden axisymmetric temperature loading combined with dynamic pressure as well as asymmetric temperature loading are also obtained. The method of Fourier series together with the Laplace transform is utilized in solving the heat conduction equation and thermal stress analysis. For brittle materials, like carbon-carbon composites, the strength variability is represented by two or three parameter Weibull distributions. The 'weakest link' principle which takes into account both the carbon-carbon composite cylinders. The complex frequency response analysis is performed on a multilayered orthotropic cylinder under asymmetrical thermal load. Both deterministic and random thermal stress and reliability analyses can be based on the results of this frequency response analysis. The stress and displacement distributions and reliability of rocket motors under static or dynamic line loads are analyzed by an elasticity approach. Rocket motors are modeled as long hollow multilayered cylinders with an air core, a thick isotropic propellant inner layer and a thin orthotropic kevlar-epoxy case. The case is treated as a single orthotropic layer or a ten layered orthotropic structure. Five material properties and the load are treated as random variable with normal distributions when the reliability of the rocket motor is analyzed by the first-order, second-moment method (FOSM).