WorldWideScience

Sample records for tandem arrangement vanes

  1. Gas turbine structural mounting arrangement between combustion gas duct annular chamber and turbine vane carrier

    Science.gov (United States)

    Wiebe, David J.; Charron, Richard C.; Morrison, Jay A.

    2016-10-18

    A gas turbine engine ducting arrangement (10), including: an annular chamber (14) configured to receive a plurality of discrete flows of combustion gases originating in respective can combustors and to deliver the discrete flows to a turbine inlet annulus, wherein the annular chamber includes an inner diameter (52) and an outer diameter (60); an outer diameter mounting arrangement (34) configured to permit relative radial movement and to prevent relative axial and circumferential movement between the outer diameter and a turbine vane carrier (20); and an inner diameter mounting arrangement (36) including a bracket (64) secured to the turbine vane carrier, wherein the bracket is configured to permit the inner diameter to move radially with the outer diameter and prevent axial deflection of the inner diameter with respect to the outer diameter.

  2. The effect of mixing-vane arrangements in a subchannel turbulent flow

    International Nuclear Information System (INIS)

    Ikeno, Tsutomu; Murata, Tamotsu; Kajishima, Takeo

    2006-01-01

    Large eddy simulation (LES) of developed turbulent flows in a rod bundle was carried out for four spacer designs. The mixing-vanes attached at the spacer were inclined at 30degC or 20deg; they were arranged to promote the swirling or convective flow. These arrangements are possible elements to compose an actual rod bundle. Our LES technique with a consistent higher-order immersed boundary method and a one-equation dynamic sub-grid scale model contributed to an efficient treatment of the complex wall configurations of rods and spacers. The computational results reasonably reproduced experimental results for the drag coefficient and the decay rate of swirling flow. The profiles of the axial velocities and the turbulence intensities indicated reasonable trend for the turbulent flow in the rod bundle. The effect of mixing-vane arrangement on the lateral flows was successfully clarified: the cross flow took the longer way on the rod surface than the swirling flow and then was more significantly influenced by momentum diffusion at the no-slip wall. Therefore, the largely inclined mixing-vanes promoted the cross flow only in the neighborhood of the spacer, the swirling flow inside a subchannel could reach farther downstream than the cross flow. (author)

  3. Influence of the Applied Working Fluid and the Arrangement of the Steering Edges on Multi-Vane Expander Performance in Micro ORC System

    Directory of Open Access Journals (Sweden)

    Józef Rak

    2018-04-01

    Full Text Available Micro-power domestic organic Rankine cycle (ORC systems are nowadays of great interest. These systems are considered for combined heat and power (CHP generation in domestic and distributed applications. The main issues of ORC systems design is selection of the expander and the working fluid. Thanks to their positive features, multi-vane expanders are especially promising for application in micro-power ORC systems. These expanders are very simple in design, small in dimensions, inexpensive and feature low gas flow capacity and expansion ratio. The application of multi-vane expanders in ORC systems is innovative and currently limited to prototype applications. However, a literature review indicates the growing interest in these machines and the potential for practical implementation. For this reason, it is necessary to conduct detailed studies on the multi-vane expanders operation in ORC systems. In this paper the results of experimental and numerical investigations on the influence of the applied working fluid and the arrangement of the steering edges on multi-vane expander performance in micro ORC system are reported. The experiments were performed using the specially designed lab test-stand, i.e. the domestic ORC system. Numerical simulations were proceeded in ANSYS CFX software (ANSYS, Inc., Canonsburg, PA, USA and were focused on determining the expander performance under various flow conditions of different working fluids. Detailed numerical analysis of the arrangement of the machine steering edges showed existence of optimal mutual position of the inlet and outlet port for which the multi-vane expander achieves maximum internal work and internal efficiency.

  4. Hydrodynamic studies on two traveling wavy foils in tandem arrangement

    Science.gov (United States)

    Deng, Jian; Shao, Xue-Ming; Yu, Zhao-Sheng

    2007-11-01

    In this study, the hydrodynamic interactions between two tandem foils undergoing fishlike swimming motion are investigated numerically by solving the Navier-Stokes equations with the immersed-boundary method. The two foils represent two tandem propellers attached on a concept ship. The thrusts and efficiencies at three typical Strouhal numbers, i.e., St =0.4, 0.6, and 0.8, are investigated. The results show that a fish situated directly behind another one does not always undergo a lower thrust. Whether it experiences a thrust enhancement or reduction depends on the Strouhal number. At a relatively low Strouhal number (e.g., St =0.4), the usual wake drag-reduction effect predominates over the drag-enhancement effect caused by the reverse von Kármán vortices, resulting in a thrust enhancement. The opposite happens at a relatively high Strouhal number (e.g., St =0.8). The downstream fish can benefit from the upstream one by slalom between the vortices rather than through them. For the upstream fish, the thrusts and efficiencies for all Strouhal numbers studied are higher than those for a single fish when the two fish are closely spaced, and approach those for a single fish as the spacing is increased.

  5. Capacity control of rotary vane apparatus

    International Nuclear Information System (INIS)

    Roberts, R. W.

    1985-01-01

    A capacity control arrangement for a rotary vane fluid displacement apparatus, such as a rotary vane compressor, having a vane retaining means that normally engages and retains the vanes in their retracted or nonworking position within the rotor defined guide slits of such rotary vane compressor. The retaining means are actuated to the vane-disengaged position by hydraulic control fluid which is communicated to the retaining means in response to an external parameter sensed by a control means

  6. Re-examination of laminar flow over twin circular cylinders in tandem arrangement

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Ming-Ming; Lu, Lin; Teng, Bin; Tang, Guo-Qiang [State Key Laboratory of Coastal and Offshore Engineering, Dalian University of Technology, Dalian 116024 (China); Zhao, Ming [School of Computing, Engineering and Mathematics, University of Western Sydney, Penrith 2751 (Australia)

    2014-04-01

    Viscous fluid flow past two identical circular cylinders in a tandem arrangement is numerically investigated at a typical Reynolds number of 200. By considering a large span of spacing ratio (0.1 ⩽ G/D ⩽ 6.0) with a fine interval of 0.1 or less, the dependences on the spacing ratio of the drag force, lift force, lift fluctuation frequency, torque on the cylinder pair and phase difference between the lift fluctuations of the two cylinders are investigated in detail, where D is the diameter of the cylinder and G the surface-to-surface distance between the cylinders. The phase difference between the lift fluctuations of the two cylinders is addressed based on correlation analysis together with the phase diagram, which has received scarce attention before. The phase difference provides further understanding to the dependence of the wake evolutions behind the twin circular cylinders. The numerical investigations show that diverse regimes can be identified according to the dependence of the hydrodynamics on the spacing ratio. The hydrodynamic discontinuities at G/D = 0.9, which have previously been ignored, are reported in this work. The physical correlations between the hydrodynamic discontinuities and the wake patterns are presented. (paper)

  7. Re-examination of laminar flow over twin circular cylinders in tandem arrangement

    International Nuclear Information System (INIS)

    Liu, Ming-Ming; Lu, Lin; Teng, Bin; Tang, Guo-Qiang; Zhao, Ming

    2014-01-01

    Viscous fluid flow past two identical circular cylinders in a tandem arrangement is numerically investigated at a typical Reynolds number of 200. By considering a large span of spacing ratio (0.1 ⩽ G/D ⩽ 6.0) with a fine interval of 0.1 or less, the dependences on the spacing ratio of the drag force, lift force, lift fluctuation frequency, torque on the cylinder pair and phase difference between the lift fluctuations of the two cylinders are investigated in detail, where D is the diameter of the cylinder and G the surface-to-surface distance between the cylinders. The phase difference between the lift fluctuations of the two cylinders is addressed based on correlation analysis together with the phase diagram, which has received scarce attention before. The phase difference provides further understanding to the dependence of the wake evolutions behind the twin circular cylinders. The numerical investigations show that diverse regimes can be identified according to the dependence of the hydrodynamics on the spacing ratio. The hydrodynamic discontinuities at G/D = 0.9, which have previously been ignored, are reported in this work. The physical correlations between the hydrodynamic discontinuities and the wake patterns are presented. (paper)

  8. Plane Wall Effect of Flow around Two Circular Cylinders in Tandem Arrangement

    Directory of Open Access Journals (Sweden)

    Triyogi Yuwono,

    2011-02-01

    Full Text Available The flow characteristic around two circular cylinders in tandem arrangement located near a plane wall were investigated experimentally in a uniform flow at a Reynolds Number of 5.3 x 104. The center to center spacing between the two cylinders relative to the cylinder diameter was constantly maintained at P/D = 1.5. The pressure distributions along the surface of the cylinder and the plane wall were measured by varying the gap-to-diameter of cylinder ratio (G/D in the range of 0 < G/D < 0.467. Surface oil-film techniques were used to investigate the flow patterns on the cylinder. The result showed that for upstream cylinder, in the gap-to-diameter ratio G/D < /D, there is no stagnation point at front side of the upstream cylinder; it is gradually raised as the gap increase. For the downstream cylinder, a peak on the lower side of the front side of the cylinder is apparent in each of the pressure distributions. This peak represents the reattachment of shear layer that separates from lower side of the upstream cylinder. The reattachment point tends to move forward close to the angular position of  = 0o as the gap ratio increase. The shear layer bifurcates into two shear layers. One shear layer continues in the downstream direction, and the other shear layer flows in the upstream direction.

  9. Genomic Organization and Physical Mapping of Tandemly Arranged Repetitive DNAs in Sterlet (Acipenser ruthenus).

    Science.gov (United States)

    Biltueva, Larisa S; Prokopov, Dimitry Y; Makunin, Alexey I; Komissarov, Alexey S; Kudryavtseva, Anna V; Lemskaya, Natalya A; Vorobieva, Nadezhda V; Serdyukova, Natalia A; Romanenko, Svetlana A; Gladkikh, Olga L; Graphodatsky, Alexander S; Trifonov, Vladimir A

    2017-01-01

    Acipenseriformes represent a phylogenetically basal clade of ray-finned fish characterized by unusual genomic traits, including paleopolyploid states of extant genomes with high chromosome numbers and slow rates of molecular evolution. Despite a high interest in this fish group, only a limited number of studies have been accomplished on the isolation and characterization of repetitive DNA, karyotype standardization is not yet complete, and sex chromosomes are still to be identified. Here, we applied next-generation sequencing and cluster analysis to characterize major fractions of sterlet (Acipenser ruthenus) repetitive DNA. Using FISH, we mapped 16 tandemly arranged sequences on sterlet chromosomes and found them to be unevenly distributed in the genome with a tendency to cluster in particular regions. Some of the satellite DNAs might be used as specific markers to identify individual chromosomes and their paralogs, resulting in the unequivocal identification of at least 18 chromosome pairs. Our results provide an insight into the characteristic genomic distribution of the most common sterlet repetitive sequences. Biased accumulation of repetitive DNAs in particular chromosomes makes them especially interesting for further search for cryptic sex chromosomes. Future studies of these sequences in other acipenserid species will provide new perspectives regarding the evolution of repetitive DNA within the genomes of this fish order. © 2017 S. Karger AG, Basel.

  10. Sliding vane geometry turbines

    Science.gov (United States)

    Sun, Harold Huimin; Zhang, Jizhong; Hu, Liangjun; Hanna, Dave R

    2014-12-30

    Various systems and methods are described for a variable geometry turbine. In one example, a turbine nozzle comprises a central axis and a nozzle vane. The nozzle vane includes a stationary vane and a sliding vane. The sliding vane is positioned to slide in a direction substantially tangent to an inner circumference of the turbine nozzle and in contact with the stationary vane.

  11. Application of Potential Theory to Steady Flow Past Two Cylinders in Tandem Arrangement

    Directory of Open Access Journals (Sweden)

    Yangyang Gao

    2014-01-01

    Full Text Available The wake flow patterns associated with flow past a cylinder and a cylinder-pair in tandem configuration are revisited, compared, and evaluated with respect to the streamline patterns generated based on potential flow theory and superposition of various potential flow elements. The wakes, which are vortex shedding in the lee of the cylinder(s, are reproduced by placing pairs of equal but opposite circulation elements in the potential flow field. The strength of the circulation elements determines the size of the vortices produced. The streamline patterns of flow past a pair of unequal cylinders in tandem configuration provide an indirect means to establish the threshold condition for the wake transition from that of a single bluff body to alternating reattachment behavior. This threshold condition is found to be a function of the diameter ratio, d/D (diameters d and D, d≤D , spacing ratio, L/D (centre-to-centre distance, L, to cylinder diameter, D, and equivalent incident flow speed, U. A unique functional relationship f (L/D, d/D, U of this threshold condition is established.

  12. TANDEM

    Data.gov (United States)

    Federal Laboratory Consortium — The Tandem Van de Graaff facility provides researchers with beams of more than 40 different types of ions - atoms that have been stripped of their electrons. One of...

  13. A Tandemly Arranged Pattern of Two 5S rDNA Arrays in Amolops mantzorum (Anura, Ranidae).

    Science.gov (United States)

    Liu, Ting; Song, Menghuan; Xia, Yun; Zeng, Xiaomao

    2017-01-01

    In an attempt to extend the knowledge of the 5S rDNA organization in anurans, the 5S rDNA sequences of Amolops mantzorum were isolated, characterized, and mapped by FISH. Two forms of 5S rDNA, type I (209 bp) and type II (about 870 bp), were found in specimens investigated from various populations. Both of them contained a 118-bp coding sequence, readily differentiated by their non-transcribed spacer (NTS) sizes and compositions. Four probes (the 5S rDNA coding sequences, the type I NTS, the type II NTS, and the entire type II 5S rDNA sequences) were respectively labeled with TAMRA or digoxigenin to hybridize with mitotic chromosomes for samples of all localities. It turned out that all probes showed the same signals that appeared in every centromeric region and in the telomeric regions of chromosome 5, without differences within or between populations. Obviously, both type I and type II of the 5S rDNA arrays arranged in tandem, which was contrasting with other frogs or fishes recorded to date. More interestingly, all the probes detected centromeric regions in all karyotypes, suggesting the presence of a satellite DNA family derived from 5S rDNA. © 2017 S. Karger AG, Basel.

  14. Numerical simulation of flow past twin near-wall circular cylinders in tandem arrangement at low Reynolds number

    Directory of Open Access Journals (Sweden)

    Guo-qiang Tang

    2015-10-01

    Full Text Available Fluid flow past twin circular cylinders in a tandem arrangement placed near a plane wall was investigated by means of numerical simulations. The two-dimensional Navier-Stokes equations were solved with a three-step finite element method at a relatively low Reynolds number of Re = 200 for various dimensionless ratios of and , where D is the cylinder diameter, L is the center-to-center distance between the two cylinders, and G is the gap between the lowest surface of the twin cylinders and the plane wall. The influences of and on the hydrodynamic force coefficients, Strouhal numbers, and vortex shedding modes were examined. Three different vortex shedding modes of the near wake were identified according to the numerical results. It was found that the hydrodynamic force coefficients and vortex shedding modes are quite different with respect to various combinations of and . For very small values of , the vortex shedding is completely suppressed, resulting in the root mean square (RMS values of drag and lift coefficients of both cylinders and the Strouhal number for the downstream cylinder being almost zero. The mean drag coefficient of the upstream cylinder is larger than that of the downstream cylinder for the same combination of and . It is also observed that change in the vortex shedding modes leads to a significant increase in the RMS values of drag and lift coefficients.

  15. Laboratory measurements of vortex- and wake-induced vibrations of a tandem arrangement of two flexible risers

    Science.gov (United States)

    Liu, Huai-zeng; Wang, Fei; Jiang, Guo-sheng; Guo, Hai-yan; Li, Xiao-min

    2016-03-01

    The dynamic response of two flexible model risers in tandem arrangement immersed in a stepped current was analyzed. The risers, with an external diameter of 20 mm and a total length of 6200 mm, had an aspect ratio of 310. They were hinged to the support structure at the center-to-center distances away 3-12 times the external diameter. The top 1200 mm was exposed to a uniform current at a speed which was up to 0.9 m/s (the Reynolds number was 18000) and the rest in still water. The dynamic responses, which were obtained through the Fiber Bragg Grating strain gauges mounted on the surface, were analyzed by studying the cross-flow amplitudes and modal weights. The cross-flow vibration were observed up to the third mode, and the modal transformation from the second mode to the third mode was clearly observed. The experiment confirmed that the typical vortex-induced vibration (VIV) had occurred on the up-stream riser. But for the down-stream riser, the main excitation mechanism was wake-induced vibration (WIV). The modal transformation of WIV was more complex than that of VIV, which might be helpful for other researchers to study the interference effect.

  16. Mixing vane grid spacer

    International Nuclear Information System (INIS)

    Patterson, J.F.; Galbraith, K.P.

    1978-01-01

    An improved mixing vane grid spacer having enhanced flow mixing capability by virtue of mixing vanes being positioned at welded intersecting joints of the spacer wherein each mixing vane has an opening or window formed therein substantially directly over the welded joint to provide improved flow mixing capability is described. Some of the vanes are slotted, depending on their particular location in the spacers. The intersecting joints are welded by initially providing consumable tabs at and within each window, which are consumed during the welding of the spacer joints

  17. Optimization of submerged vane parameters

    Indian Academy of Sciences (India)

    H Sharma

    the height or length of the submerged vane, no effective change in bed profile .... easily and again vanes will be ineffective, which is what. Odgaard and .... [3] Odgaard A J and Wang Y 1991a Sediment management with submerged vanes.

  18. Rumsansning mellem vane og oplevelse

    DEFF Research Database (Denmark)

    Reeh, Henrik

    2004-01-01

    Walter Benjamin, Steen Eiler Rasmussen, arkitektur, sansning, vane, taktilitet, oplevelse, erfaring, Rom......Walter Benjamin, Steen Eiler Rasmussen, arkitektur, sansning, vane, taktilitet, oplevelse, erfaring, Rom...

  19. Tandemly arranged chalcone synthase A genes contribute to the spatially regulated expression of siRNA and the natural bicolor floral phenotype in Petunia hybrida.

    Science.gov (United States)

    Morita, Yasumasa; Saito, Ryoko; Ban, Yusuke; Tanikawa, Natsu; Kuchitsu, Kazuyuki; Ando, Toshio; Yoshikawa, Manabu; Habu, Yoshiki; Ozeki, Yoshihiro; Nakayama, Masayoshi

    2012-06-01

    The natural bicolor floral traits of the horticultural petunia (Petunia hybrida) cultivars Picotee and Star are caused by the spatial repression of the chalcone synthase A (CHS-A) gene, which encodes an anthocyanin biosynthetic enzyme. Here we show that Picotee and Star petunias carry the same short interfering RNA (siRNA)-producing locus, consisting of two intact CHS-A copies, PhCHS-A1 and PhCHS-A2, in a tandem head-to-tail orientation. The precursor CHS mRNAs are transcribed from the two CHS-A copies throughout the bicolored petals, but the mature CHS mRNAs are not found in the white tissues. An analysis of small RNAs revealed the accumulation of siRNAs of 21 nucleotides that originated from the exon 2 region of both CHS-A copies. This accumulation is closely correlated with the disappearance of the CHS mRNAs, indicating that the bicolor floral phenotype is caused by the spatially regulated post-transcriptional silencing of both CHS-A genes. Linkage between the tandemly arranged CHS-A allele and the bicolor floral trait indicates that the CHS-A allele is a necessary factor to confer the trait. We suppose that the spatially regulated production of siRNAs in Picotee and Star flowers is triggered by another putative regulatory locus, and that the silencing mechanism in this case may be different from other known mechanisms of post-transcriptional gene silencing in plants. A sequence analysis of wild Petunia species indicated that these tandem CHS-A genes originated from Petunia integrifolia and/or Petunia inflata, the parental species of P. hybrida, as a result of a chromosomal rearrangement rather than a gene duplication event. © 2012 The Authors. The Plant Journal © 2012 Blackwell Publishing Ltd.

  20. Gas turbine vane platform element

    Science.gov (United States)

    Campbell, Christian X [Oviedo, FL; Schiavo, Anthony L [Oviedo, FL; Morrison, Jay A [Oviedo, FL

    2012-08-28

    A gas turbine CMC shroud plate (48A) with a vane-receiving opening (79) that matches a cross-section profile of a turbine vane airfoil (22). The shroud plate (48A) has first and second curved circumferential sides (73A, 74A) that generally follow the curves of respective first and second curved sides (81, 82) of the vane-receiving opening. Walls (75A, 76A, 77A, 78A, 80, 88) extend perpendicularly from the shroud plate forming a cross-bracing structure for the shroud plate. A vane (22) may be attached to the shroud plate by pins (83) or by hoop-tension rings (106) that clamp tabs (103) of the shroud plate against bosses (105) of the vane. A circular array (20) of shroud plates (48A) may be assembled to form a vane shroud ring in which adjacent shroud plates are separated by compressible ceramic seals (93).

  1. Heat pipe turbine vane cooling

    Energy Technology Data Exchange (ETDEWEB)

    Langston, L.; Faghri, A. [Univ. of Connecticut, Storrs, CT (United States)

    1995-10-01

    The applicability of using heat pipe principles to cool gas turbine vanes is addressed in this beginning program. This innovative concept involves fitting out the vane interior as a heat pipe and extending the vane into an adjacent heat sink, thus transferring the vane incident heat transfer through the heat pipe to heat sink. This design provides an extremely high heat transfer rate and an uniform temperature along the vane due to the internal change of phase of the heat pipe working fluid. Furthermore, this technology can also eliminate hot spots at the vane leading and trailing edges and increase the vane life by preventing thermal fatigue cracking. There is also the possibility of requiring no bleed air from the compressor, and therefore eliminating engine performance losses resulting from the diversion of compressor discharge air. Significant improvement in gas turbine performance can be achieved by using heat pipe technology in place of conventional air cooled vanes. A detailed numerical analysis of a heat pipe vane will be made and an experimental model will be designed in the first year of this new program.

  2. Analysis of swirl recovery vanes for increased propulsive efficiency in tractor propeller aircraft

    NARCIS (Netherlands)

    Veldhuis, L.L.M.; Stokkermans, T.C.A.; Sinnige, T.; Eitelberg, G.

    2016-01-01

    In this paper we address a preliminary assessment of the performance effects of swirl recovery vanes (SRVs) in a installed and uninstalled tractor propeller arrangement. A numerical analysis was performed on a propeller and a propeller-wing configuration after the SRVs were optimized first in a

  3. Solar energy system with wind vane

    Science.gov (United States)

    Grip, Robert E

    2015-11-03

    A solar energy system including a pedestal defining a longitudinal axis, a frame that is supported by the pedestal and that is rotateable relative to the pedestal about the longitudinal axis, the frame including at least one solar device, and a wind vane operatively connected to the frame to urge the frame relative to the pedestal about the longitudinal axis in response to wind acting on the wind vane.

  4. An Empirical Model for Vane-Type Vortex Generators in a Navier-Stokes Code

    Science.gov (United States)

    Dudek, Julianne C.

    2005-01-01

    An empirical model which simulates the effects of vane-type vortex generators in ducts was incorporated into the Wind-US Navier-Stokes computational fluid dynamics code. The model enables the effects of the vortex generators to be simulated without defining the details of the geometry within the grid, and makes it practical for researchers to evaluate multiple combinations of vortex generator arrangements. The model determines the strength of each vortex based on the generator geometry and the local flow conditions. Validation results are presented for flow in a straight pipe with a counter-rotating vortex generator arrangement, and the results are compared with experimental data and computational simulations using a gridded vane generator. Results are also presented for vortex generator arrays in two S-duct diffusers, along with accompanying experimental data. The effects of grid resolution and turbulence model are also examined.

  5. Seal arrangement

    International Nuclear Information System (INIS)

    Dempsey, J.D.

    1978-01-01

    A hydraulically balanced face type shaft seal is provided in which the opening and closing seal face areas retain concentricity with each other in the event of lateral shaft displacement. The seal arrangement is for a vertical high pressure pump, indented for use in the cooling system of a nuclear reactor. (Auth.)

  6. Design Concepts for Cooled Ceramic Matrix Composite Turbine Vanes

    Science.gov (United States)

    Boyle, Robert

    2014-01-01

    This project demonstrated that higher temperature capabilities of ceramic matrix composites (CMCs) can be used to reduce emissions and improve fuel consumption in gas turbine engines. The work involved closely coupling aerothermal and structural analyses for the first-stage vane of a high-pressure turbine (HPT). These vanes are actively cooled, typically using film cooling. Ceramic materials have structural and thermal properties different from conventional metals used for the first-stage HPT vane. This project identified vane configurations that satisfy CMC structural strength and life constraints while maintaining vane aerodynamic efficiency and reducing vane cooling to improve engine performance and reduce emissions. The project examined modifications to vane internal configurations to achieve the desired objectives. Thermal and pressure stresses are equally important, and both were analyzed using an ANSYS® structural analysis. Three-dimensional fluid and heat transfer analyses were used to determine vane aerodynamic performance and heat load distributions.

  7. Split coaxial RFQ structure with modulated vanes

    International Nuclear Information System (INIS)

    Arai, S.

    1983-10-01

    A new split coaxial RFO structure with modulated vanes is proposed. The structure is designed to accelerate 238 U 4+ from 1.68 keV/u to 45.1 keV/u at frequency of 12.5 MHz. The cavity is 1.6 m in diameter and 8 m in length. The cavity consists of four cavity modules divided by three stems which support horizontal and vertical vanes periodically and alternatively. At the same time, problems on the beam dynamics and design procedures are described and discussed. (orig.)

  8. Computational model for turbulent flow around a grid spacer with mixing vane

    International Nuclear Information System (INIS)

    Tsutomu Ikeno; Takeo Kajishima

    2005-01-01

    Turbulent mixing coefficient and pressure drop are important factors in subchannel analysis to predict onset of DNB. However, universal correlations are difficult since these factors are significantly affected by the geometry of subchannel and a grid spacer with mixing vane. Therefore, we propose a computational model to estimate these factors. Computational model: To represent the effect of geometry of grid spacer in computational model, we applied a large eddy simulation (LES) technique in couple with an improved immersed-boundary method. In our previous work (Ikeno, et al., NURETH-10), detailed properties of turbulence in subchannel were successfully investigated by developing the immersed boundary method in LES. In this study, additional improvements are given: new one-equation dynamic sub-grid scale (SGS) model is introduced to account for the complex geometry without any artificial modification; the higher order accuracy is maintained by consistent treatment for boundary conditions for velocity and pressure. NUMERICAL TEST AND DISCUSSION: Turbulent mixing coefficient and pressure drop are affected strongly by the arrangement and inclination of mixing vane. Therefore, computations are carried out for each of convolute and periodic arrangements, and for each of 30 degree and 20 degree inclinations. The difference in turbulent mixing coefficient due to these factors is reasonably predicted by our method. (An example of this numerical test is shown in Fig. 1.) Turbulent flow of the problem includes unsteady separation behind the mixing vane and vortex shedding in downstream. Anisotropic distribution of turbulent stress is also appeared in rod gap. Therefore, our computational model has advantage for assessing the influence of arrangement and inclination of mixing vane. By coarser computational mesh, one can screen several candidates for spacer design. Then, by finer mesh, more quantitative analysis is possible. By such a scheme, we believe this method is useful

  9. Precision Model for Microwave Rotary Vane Attenuator

    DEFF Research Database (Denmark)

    Guldbrandsen, Tom

    1979-01-01

    A model for a rotary vane attenuator is developed to describe the attenuator reflection and transmission coefficients in detail. All the parameters of the model can be measured in situ, i.e., without diassembling any part. The tranmission errors caused by internal reflections are calculated from ...

  10. CMC vane assembly apparatus and method

    Science.gov (United States)

    Schiavo, Anthony L; Gonzalez, Malberto F; Huang, Kuangwei; Radonovich, David C

    2012-10-23

    A metal vane core or strut (64) is formed integrally with an outer backing plate (40). An inner backing plate (38) is formed separately. A spring (74) with holes (75) is installed in a peripheral spring chamber (76) on the strut. Inner and outer CMC shroud covers (46, 48) are formed, cured, then attached to facing surfaces of the inner and outer backing plates (38, 40). A CMC vane airfoil (22) is formed, cured, and slid over the strut (64). The spring (74) urges continuous contact between the strut (64) and airfoil (66), eliminating vibrations while allowing differential expansion. The inner end (88) of the strut is fastened to the inner backing plate (38). A cooling channel (68) in the strut is connected by holes (69) along the leading edge of the strut to peripheral cooling paths (70, 71) around the strut. Coolant flows through and around the strut, including through the spring holes.

  11. Vane coupling rings: a simple technique for stabilizing a four-vane radiofrequency quadrupole structure

    International Nuclear Information System (INIS)

    Howard, D.; Lancaster, H.

    1983-01-01

    The benefits of stabilized accelerating structures, with regard to the manufacture and operation, have been well documented. The four-vane radiofrequency quadrupoles (RFQ) presently being designed and constructed in many laboratories are not stabilized because of the weak electromagnetic coupling between the quadrant resonators. This paper presents a simple technique developed at the Lawrence Berkeley Laboratory using vane coupling rings (VCR's) which azimuthally stabilize the RFQ structure and greatly enhance its use as a practical accelerator. In particular, the VCR's: Completely eliminate the dipole modes in the frequency range of interest; Provide adequate quadrant balance with an initial precision mechanical alignment of the vanes; Enhance axial balance and simplify end tuners. Experimental verification tests on a scale model will be discussed

  12. Vane coupling rings: a simple technique for stabilizing a four-vane radiofrequency quadrupole structure

    International Nuclear Information System (INIS)

    Howard, D.; Lancaster, H.

    1982-11-01

    The benefits of stabilized accelerating structures, with regard to the manufacture and operation, have been well documented. The four-vane radiofrequency quadrupoles (RFQ) presently being designed and constructed in many laboratories are not stabilized because of the weak electromagnetic coupling between the quadrant resonators. This paper presents a simple technique developed at the Lawrence Berkeley Laboratory using vane coupling rings (VCR's) which azimuthally stabilize the RFQ structure and greatly enhance its use as a practical accelerator. In particular, the VCR's: completely eliminate the dipole modes in the frequency range of interest; provide adequate quadrant balance with an initial precision mechanical alignment of the vanes; and enhance axial balance and simplify end tuners. Experimental verification tests on a scale model are discussed

  13. Flow characteristics of guide vane of diffuser pump by PIV measurement

    International Nuclear Information System (INIS)

    Kim, J. H.; Lee, Young Ho; Choi, J. W.; Kim, M. Y.; Lee, H.

    2000-01-01

    The present experimental study is focused on the application of multi-point simultaneous measurement by PIV(Particle Image Velocimetry) to guide vane region within a diffuser pump. Various different kinds of clearance were selected as experimental conditions. Optimized cross correlation identification to obtain velocity vectors was implemented with direct calculation of correlation coefficients. Fine optical setup important in PIV performance is arranged for the accurate PIV measurement of high-speed complex flow. Various flow patterns are represented quantitatively at the stator passages

  14. Vane-Cam - camshaft controls with new functionalities; Vane-Cam - Nockenwellenversteller mit neuen Funktionalitaeten

    Energy Technology Data Exchange (ETDEWEB)

    Knecht, A.; Pohl, D. [Hydraulik-Ring GmbH, Nuertingen (Germany); Hannibal, W. [Fachhochschule Suedwestfalen, Iserlohn (Germany). Labor fuer Konstruktion und CAE-Anwendungen; enTec Consulting GmbH, Hemer (Germany)

    2007-01-15

    Infinitely variable camshaft phasing systems will be used in the future in practically all gasoline internal combustion engines high volume production. This paper of Hydraulik-Ring GmbH gives an overview of the current system concepts of the latest generation of camshaft controls utilizing the principle of the vane motor. (orig.)

  15. Vane clocking effects in an embedded compressor stage

    Science.gov (United States)

    Key, Nicole Leanne

    The objective of this research was to experimentally investigate the effects of vane clocking, the circumferential indexing of adjacent vane rows with similar vane counts, in an embedded compressor stage. Experiments were performed in the Purdue 3-Stage Compressor, which consists of an IGV followed by three stages. The IGV, Stator 1, and Stator 2 have identical vane counts of 44, and the effects of clocking were studied on Stage 2. The clocking configuration that located the upstream vane wake on the Stator 2 leading edge was identified with total pressure measurements at the inlet to Stator 2 and confirmed with measurements at the exit of Stator 2. For both loading conditions, the total temperature results showed that there was no measurable change associated with vane clocking in the amount of work done on the flow. At design loading, the change in stage efficiency with vane clocking was 0.27 points between the maximum and minimum efficiency clocking configurations. The maximum efficiency configuration was the case where the Stator 1 wake impinged on the Stator 2 leading edge. This condition produced a shallower and thinner Stator 2 wake compared to the clocking configuration that located the wake in the middle of the Stator 2 passage. By locating the Stator 1 wake at the leading edge, it dampened the Stator 2 boundary layer response to inlet fluctuations associated with the Rotor 2 wakes. At high loading, the change in Stage 2 efficiency increased to 1.07 points; however, the maximum efficiency clocking configuration was the case where the Stator 1 wake passed through the middle of the downstream vane passage. At high loading, the flow physics associated with vane clocking were different than at design loading because the location of the Stator 1 wake fluid on the Stator 2 leading edge triggered a boundary layer separation on the suction side of Stator 2 producing a wider and deeper wake. Vane clocking essentially affects the amount of interaction between the

  16. A horizontal vane radiometer: Experiment, theory, and simulation

    Energy Technology Data Exchange (ETDEWEB)

    Wolfe, David; Larraza, Andres, E-mail: larraza@nps.edu [Department of Physics, Naval Postgraduate School, Monterey, California 93940 (United States); Garcia, Alejandro [Department of Physics and Astronomy, San Jose State University, San Jose, California 95152 (United States)

    2016-03-15

    The existence of two motive forces on a Crookes radiometer has complicated the investigation of either force independently. The thermal creep shear force in particular has been subject to differing interpretations of the direction in which it acts and its order of magnitude. In this article, we provide a horizontal vane radiometer design which isolates the thermal creep shear force. The horizontal vane radiometer is explored through experiment, kinetic theory, and the Direct Simulation Monte Carlo (DSMC) method. The qualitative agreement between the three methods of investigation is good except for a dependence of the force on the width of the vane even when the temperature gradient is narrower than the vane which is present in the DSMC method results but not in the theory. The experimental results qualitatively resemble the theory in this regard. The quantitative agreement between the three methods of investigation is better than an order of magnitude in the cases examined. The theory is closer to the experimental values for narrow vanes and the simulations are closer to the experimental values for the wide vanes. We find that the thermal creep force acts from the hot side to the cold side of the vane. We also find the peak in the radiometer’s angular speed as a function of pressure is explained as much by the behavior of the drag force as by the behavior of the thermal creep force.

  17. A horizontal vane radiometer: Experiment, theory, and simulation

    International Nuclear Information System (INIS)

    Wolfe, David; Larraza, Andres; Garcia, Alejandro

    2016-01-01

    The existence of two motive forces on a Crookes radiometer has complicated the investigation of either force independently. The thermal creep shear force in particular has been subject to differing interpretations of the direction in which it acts and its order of magnitude. In this article, we provide a horizontal vane radiometer design which isolates the thermal creep shear force. The horizontal vane radiometer is explored through experiment, kinetic theory, and the Direct Simulation Monte Carlo (DSMC) method. The qualitative agreement between the three methods of investigation is good except for a dependence of the force on the width of the vane even when the temperature gradient is narrower than the vane which is present in the DSMC method results but not in the theory. The experimental results qualitatively resemble the theory in this regard. The quantitative agreement between the three methods of investigation is better than an order of magnitude in the cases examined. The theory is closer to the experimental values for narrow vanes and the simulations are closer to the experimental values for the wide vanes. We find that the thermal creep force acts from the hot side to the cold side of the vane. We also find the peak in the radiometer’s angular speed as a function of pressure is explained as much by the behavior of the drag force as by the behavior of the thermal creep force.

  18. Demonstration and Field Evaluation of Streambank Stabilization with Submerged Vanes

    Science.gov (United States)

    Whitman, H.; Hoopes, J.; Poggi, D.; Fitzpatrick, F.; Walz, K.; ,

    2001-01-01

    The effectiveness of submerged vanes for reducing bank erosion and improving aquatic habitat is being evaluated at a site on North Fish Creek, a Lake Superior tributary. Increased runoff from agricultural areas with clayey soils has increased flood magnitudes and the erosion potential/transport capacity of the stream. Most of the creek's sediment load originates from the erosion of 17 large bluffs. This creek contains important recreational fisheries that are potentially limited by the loss of aquatic habitat from deposition of sediment on spawning beds. Submerged vanes are a cost effective and environmentally less intrusive alternative to traditional structural stabilization measures. Submerged vanes protrude from a channel bed, are oriented at an angle to the local velocity, and are distributed along a portion of channel. They induce a transverse force and torque on the flow along with longitudinal vortexes that alter the cross sectional shape and alignment of the channel. Submerged vanes were installed at a bluff/bend site in summer and fall 2000. The number, size, and layout of the vanes were based upon the channel morphology under estimated bankfull conditions. The effectiveness of the vanes will be evaluated by comparing surveys of the bluff face, streamflow, and channel conditions for several years after installation of the submerged vanes with surveys before and immediately after their installation.

  19. Sequential cooling insert for turbine stator vane

    Science.gov (United States)

    Jones, Russel B

    2017-04-04

    A sequential flow cooling insert for a turbine stator vane of a small gas turbine engine, where the impingement cooling insert is formed as a single piece from a metal additive manufacturing process such as 3D metal printing, and where the insert includes a plurality of rows of radial extending impingement cooling air holes alternating with rows of radial extending return air holes on a pressure side wall, and where the insert includes a plurality of rows of chordwise extending second impingement cooling air holes on a suction side wall. The insert includes alternating rows of radial extending cooling air supply channels and return air channels that form a series of impingement cooling on the pressure side followed by the suction side of the insert.

  20. Optimization analysis of a new vane MRF damper

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, J Q; Feng, Z Z; Jing, Q [Department of Technical Support Engineering, Academy of Armored Force Engineering, Beijing, 100072 (China)], E-mail: zhangjq63@yahoo.com.cn

    2009-02-01

    The primary purpose of this study was to provide the optimization analysis certain characteristics and benefits of a vane MRF damper. Based on the structure of conventional vane hydraulic damper for heavy vehicle, a narrow arc gap between clapboard and rotary vane axle, which one rotates relative to the other, was designed for MRF valve and the mathematical model of damping was deduced. Subsequently, the finite element analysis of electromagnetic circuit was done by ANSYS to perform the optimization process. Some ways were presented to augment the damping adjustable multiple under the condition of keeping initial damping forces and to increase fluid dwell time through the magnetic field. The results show that the method is useful in the design of MR dampers and the damping adjustable range of vane MRF damper can meet the requirement of heavy vehicle semi-active suspension system.

  1. Turbocharger with variable nozzle having vane sealing surfaces

    Science.gov (United States)

    Arnold, Philippe [Hennecourt, FR; Petitjean, Dominique [Julienrupt, FR; Ruquart, Anthony [Thaon les Vosges, FR; Dupont, Guillaume [Thaon les Vosges, FR; Jeckel, Denis [Thaon les Vosges, FR

    2011-11-15

    A variable nozzle for a turbocharger includes a plurality of vanes rotatably mounted on a nozzle ring and disposed in a nozzle flow path defined between the nozzle ring and an opposite nozzle wall. Either or both of the faces of the nozzle ring and nozzle wall include(s) at least one step that defines sealing surfaces positioned to be substantially abutted by airfoil surfaces of the vanes in the closed position of the vanes and to be spaced from the airfoil surfaces in positions other than the closed position. This substantial abutment between the airfoil surfaces and the sealing surfaces serves to substantially prevent exhaust gas from leaking past the ends of the airfoil portions. At the same time, clearances between the nozzle ring face and the end faces of the airfoil portions can be sufficiently large to prevent binding of the vanes under all operating conditions.

  2. Bed erosion control at 60 degree river confluence using vanes

    Science.gov (United States)

    Wuppukondur, Ananth; Chandra, Venu

    2017-04-01

    Confluences are common occurrences along natural rivers. Hydrodynamics at the confluence is complex due to merging of main and lateral flows with different characteristics. Bed erosion occurs at the confluence due to turbulence and also secondary circulation induced by centrifugal action of the lateral flow. The eroded sediment poses various problems in the river ecosystem including river bank failure. Reservoirs are majorly affected due to sediment deposition which reduces storage capacity. The bed erosion also endangers stability of pipeline crossings and bridge piers. The aim of this experimental study is to check the performance of vanes in controlling bed erosion at the confluence. Experiments are performed in a 600 confluence mobile bed model with a non-uniform sediment of mean particle size d50 = 0.28mm. Discharge ratio (q=ratio of lateral flow discharge to main flow discharge) is maintained as 0.5 and 0.75 with a constant average main flow depth (h) of 5cm. Vanes of width 0.3h (1.5cm) and thickness of 1 mm are placed along the mixing layer at an angle of 150, 300 and 600(with respect to main flow) to perform the experiments. Also, two different spacing of 2h and 3h (10cm and 15cm) between the vanes are used for conducting the experiments. A digital point gauge with an accuracy of ±0.1mm is used to measure bed levels and flow depths at the confluence. An Acoustic Doppler Velocitimeter (ADV) with a frequency of 25Hz and accuracy of ±1mm/s is used to measure flow velocities. Maximum scour depth ratio Rmax, which is ratio between maximum scour depth (Ds) and flow depth (h), is used to present the experimental results.From the experiments without vanes, it is observed that the velocities are increasing along the mixing layer and Rmax=0.82 and 1.06, for q=0.5 and 0.75, respectively. The velocities reduce with vanes since roughness increases along the mixing layer. For q=0.5 and 0.75, Rmax reduces to 0.62 and 0.7 with vanes at 2h spacing, respectively. Similarly

  3. Twisted Vanes Would Enhance Fuel/Air Mixing In Turbines

    Science.gov (United States)

    Nguyen, H. Lee; Micklow, Gerald J.; Dogra, Anju S.

    1994-01-01

    Computations of flow show performance of high-shear airblast fuel injector in gas-turbine engine enhanced by use of appropriately proportioned twisted (instead of flat) dome swirl vanes. Resultant more nearly uniform fuel/air mixture burns more efficiently, emitting smaller amounts of nitrogen oxides. Twisted-vane high-shear airblast injectors also incorporated into paint sprayers, providing advantages of low pressure drop characteristic of airblast injectors in general and finer atomization of advanced twisted-blade design.

  4. ESRC guide vanes of hydraulic turbine for Three Gorges project

    Directory of Open Access Journals (Sweden)

    Rui CHEN

    2005-05-01

    Full Text Available The mechanical properties and internal quality of low carbon martensite Electroslag Remelting Casting (ESRCstainless steel castings are superior to that of sand casting ones. The key technologies for the equipments and ESRC processes have been resolved during the experimental research period of guide vanes of hydraulic turbines for Three Gorges project. And ESRC guide vanes of hydraulic turbines for Three Gorges project have been produced successfully.

  5. A horizontal vane radiometer: experiment, theory and simulation

    OpenAIRE

    Wolfe, David; Lazarra, Andres; Garcia, Alejandro

    2015-01-01

    The existence of two motive forces on a Crookes radiometer has complicated the investigation of either force independently. The thermal creep shear force in particular has been subject to differing interpretations of the direction in which it acts and its order of magnitude. In this article we provide a horizontal vane radiometer design which isolates the thermal creep shear force. The horizontal vane radiometer is explored through experiment, kinetic theory, and the Direct Simulation Monte C...

  6. Effect of Curved Radial Vane Cavity Arrangements on Predicted Inter-Turbine Burner (ITB) Performance

    Science.gov (United States)

    2007-06-01

    in the cavity, and the vaporization, mixing of fuel and air, and combustion amount of unburned fuel shedding out of the becomes very challenging ...the payoff UUC/ITB concepts becomes critical. UCC/ITB was provided to define the geometry and served flamy hco de wih a ane as the staring point for...for the development and equations for mass, momentum, energy, chemical species, modification of the computer- aided design models, as and turbulence were

  7. Design Concepts for Cooled Ceramic Composite Turbine Vane

    Science.gov (United States)

    Boyle, Robert J.; Parikh, Ankur H.; Nagpal, VInod K.

    2015-01-01

    The objective of this work was to develop design concepts for a cooled ceramic vane to be used in the first stage of the High Pressure Turbine(HPT). To insure that the design concepts were relevant to the gas turbine industry needs, Honeywell International Inc. was subcontracted to provide technical guidance for this work. The work performed under this contract can be divided into three broad categories. The first was an analysis of the cycle benefits arising from the higher temperature capability of Ceramic Matrix Composite(CMC) compared with conventional metallic vane materials. The second category was a series of structural analyses for variations in the internal configuration of first stage vane for the High Pressure Turbine(HPT) of a CF6 class commercial airline engine. The third category was analysis for a radial cooled turbine vanes for use in turboshaft engine applications. The size, shape and internal configuration of the turboshaft engine vanes were selected to investigate a cooling concept appropriate to small CMC vanes.

  8. The influence of the vane on the lubrication characteristics between the vane and the rolling piston of a rotary compressor

    International Nuclear Information System (INIS)

    Cho, Ihn Sung; Jung, Jae Youn

    2006-01-01

    The rolling piston type rotary compressor has been widely used for refrigeration and air -conditioning systems due to its compactness and high-speed operation. The present analysis is part of a research program directed toward maximizing the advantages of refrigerant compressors. The study of lubrication characteristics in the critical sliding component is essential for the design of refrigerant compressors. Therefore, theoretical investigation of the lubrication characteristics of a rotary compressor being used for refrigeration and air-conditioning systems was investigated. The Newton-Raphson method was used for a partial elastohydrodynamic lubrication analysis between the vane and the rolling piston of a rotary compressor. The results demonstrated that the vane thickness and the center line position of the vane significantly influenced the friction force and the energy loss between the vane and the rolling piston

  9. A lightweight, biological structure with tailored stiffness: The feather vane.

    Science.gov (United States)

    Sullivan, Tarah N; Pissarenko, Andreï; Herrera, Steven A; Kisailus, David; Lubarda, Vlado A; Meyers, Marc A

    2016-09-01

    The flying feathers of birds are keratinous appendages designed for maximum performance with a minimum weight penalty. Thus, their design contains ingenious combinations of components that optimize lift, stiffness, aerodynamics, and damage resistance. This design involves two main parts: a central shaft that prescribes stiffness and lateral vanes which allows for the capture of air. Within the feather vane, barbs branch from the shaft and barbules branch from barbs, forming a flat surface which ensures lift. Microhooks at the end of barbules hold barbs tightly together, providing the close-knit, unified structure of the feather vane and enabling a repair of the structure through the reattachment of un-hooked junctions. Both the shaft and barbs are lightweight biological structures constructed of keratin using the common motif of a solid shell and cellular interior. The cellular core increases the resistance to buckling with little added weight. Here we analyze the detailed structure of the feather barb and, for the first time, explain its flexural stiffness in terms of the mechanics of asymmetric foam-filled beams subjected to bending. The results are correlated and validated with finite element modeling. We compare the flexure of single barbs as well as arrays of barbs and find that the interlocking adherence of barbs to one another enables a more robust structure due to minimized barb rotation during deflection. Thus, the flexure behavior of the feather vane can be tailored by the adhesive hooking between barbs, creating a system that mitigates damage. A simplified three-dimensional physical model for this interlocking mechanism is constructed by additive manufacturing. The exceptional architecture of the feather vane will motivate the design of bioinspired structures with tailored and unique properties ranging from adhesives to aerospace materials. Despite its importance to bird flight, literature characterizing the feather vane is extremely limited. The feather

  10. Design Considerations for Ceramic Matrix Composite Vanes for High Pressure Turbine Applications

    Science.gov (United States)

    Boyle, Robert J.; Parikh, Ankur H.; Nagpal, Vinod K.; Halbig, Michael C.

    2013-01-01

    Issues associated with replacing conventional metallic vanes with Ceramic Matrix Composite (CMC) vanes in the first stage of the High Pressure Turbine (HPT) are explored. CMC materials have higher temperature capability than conventional HPT vanes, and less vane cooling is required. The benefits of less vane coolant are less NOx production and improved vane efficiency. Comparisons between CMC and metal vanes are made at current rotor inlet temperatures and at an vane inlet pressure of 50 atm.. CMC materials have directionally dependent strength characteristics, and vane designs must accommodate these characteristics. The benefits of reduced NOx and improved cycle efficiency obtainable from using CMC vanes. are quantified Results are given for vane shapes made of a two dimensional CMC weave. Stress components due to thermal and pressure loads are shown for all configurations. The effects on stresses of: (1) a rib connecting vane pressure and suction surfaces; (2) variation in wall thickness; and (3) trailing edge region cooling options are discussed. The approach used to obtain vane temperature distributions is discussed. Film cooling and trailing edge ejection were required to avoid excessive vane material temperature gradients. Stresses due to temperature gradients are sometimes compressive in regions where pressure loads result in high tensile stresses.

  11. Optical Arrangement and Method

    DEFF Research Database (Denmark)

    2010-01-01

    Processing of electromagnetic radiation is described, said incoming electromagnetic radiation comprising radiation in a first wavelength interval and a plurality of spatial frequencies. An arrangement comprises a focusing arrangement for focusing the incoming electromagnetic radiation, a first ca...

  12. Voluntary Environmental Governance Arrangements

    NARCIS (Netherlands)

    van der Heijden, J.

    2012-01-01

    Voluntary environmental governance arrangements have focal attention in studies on environmental policy, regulation and governance. The four major debates in the contemporary literature on voluntary environmental governance arrangements are studied. The literature falls short of sufficiently

  13. On arrangements of pseudohyperplanes

    Indian Academy of Sciences (India)

    To every realizable oriented matroid there corresponds an arrangement of ... An important object missing in the context of pseudo-arrangements is an analogue ...... to extend this correspondence we use the language of metrical-hemisphere ...

  14. A new wind vane for the measurement of atmospheric turbulence

    Energy Technology Data Exchange (ETDEWEB)

    Parker, M.J.; Heverly, M.

    1997-02-01

    A Cooperative Research and Development Agreement (CRADA) between Met One Instruments, Incorporated (Met One) and Westinghouse Savannah River Company (WSRC) was created to develop a new wind vane that more accurately measures atmospheric turbulence. Through a process that had several phases, Met One created a prototype vane that was designed to attach to the existing Model 1585 Bi-Directional Wind Vane instrument structure. The prototype contained over 20% less mass to enhance responsiveness, which was also increased through the use of a teardrop-shaped fin structure. The prototype vane can be readily manufactured for commercial retail. Tests in wind tunnel of Building 735-7A, the Meteorological Engineering Facility, indicated that the new vane has a superior starting threshold of less than 0.14 meter per second, a delay distance of 0.72 meter, and a damping ratio of 0.4. The relative accuracy of less than one degree is unchanged from the previous design. The vane bias was acceptable at 0.8 degree for the horizontal wind angle, but was slightly high at 1.4 degree for the verticle wind angle. The high value of the verticle wind angle bias can most likely be reduced to the desired less than one degree value with standard manufacturing production techniques. The durability of the prototype vane was not tested in the field but is expected to be slightly less due to the use of hollow rather than foam-filled fins. However, the loss of some durability is more than compensated with increased sensitivity at low wind speeds. Field testing of the prototype is required to test for adequacy of durability.

  15. Study of the laboratory Vane test on mortars

    Energy Technology Data Exchange (ETDEWEB)

    Bauer, Elton [Post-Graduate Program in Structures and Civil Construction, Civil and Environmental Engineering Department, University of Brasilia Campus Universitario Darcy Ribeiro Asa Norte, 70910-900 Brasilia/DF (Brazil); Sousa, Jose G.G. de [Federal University of Vale do Sao Francisco, Av. Presidente Tancredo Neve, 100-56306-410 Petroline/PE (Brazil); Guimaraes, Elvio A. [University of Feira de Santana, Campus Universitario-BR 116, Km 03-44031-460-Feira de Santana/BA (Brazil); Silva, Francisco Gabriel S. [Post-Graduate Program in Structures and Civil Construction, University of Brasilia Campus Universitario Darcy Ribeiro Asa Norte, 70910-900 Brasilia/DF (Brazil)

    2007-01-15

    The Vane method (Vane test) is a simple but efficient method to measure the yield stress among other properties of non-Newtonian fluids. These fluids exhibit big flow effects in flat surfaces which are common in rheometers devices of different types (parallel disk or coaxial cylinder types). The yield stress values obtained with Vane method, in pastes, gels, soils and concentrated suspensions, have presented good agreement with results found elsewhere by most of the rheologic methods shown in the literature. The aim of this work is presenting a discussion on the capabilities of the Vane method, highlighting the theoretical basis, the functioning principle with some operational particularities, and some applications of the method in investigating the properties of fresh rendering mortars. Works of several authors that used the same method for fresh mortars were reviewed and experimental results of tests done by the authors of this paper using the method are also presented and discussed, focusing on the desirable workability for mortars. The Vane test method is an important tool in studying rheological properties in freshly applied mortar. It is able to define clear conditions in the applying of this material. (author)

  16. Turbofan gas turbine engine with variable fan outlet guide vanes

    Science.gov (United States)

    Wood, Peter John (Inventor); LaChapelle, Donald George (Inventor); Grant, Carl (Inventor); Zenon, Ruby Lasandra (Inventor); Mielke, Mark Joseph (Inventor)

    2010-01-01

    A turbofan gas turbine engine includes a forward fan section with a row of fan rotor blades, a core engine, and a fan bypass duct downstream of the forward fan section and radially outwardly of the core engine. The forward fan section has only a single stage of variable fan guide vanes which are variable fan outlet guide vanes downstream of the forward fan rotor blades. An exemplary embodiment of the engine includes an afterburner downstream of the fan bypass duct between the core engine and an exhaust nozzle. The variable fan outlet guide vanes are operable to pivot from a nominal OGV position at take-off to an open OGV position at a high flight Mach Number which may be in a range of between about 2.5-4+. Struts extend radially across a radially inwardly curved portion of a flowpath of the engine between the forward fan section and the core engine.

  17. Pressure Drop Test of Hybrid Mixing Vane Spacer Grid

    Energy Technology Data Exchange (ETDEWEB)

    Oh, D. S.; Chang, S. K.; Kim, B. D.; Chun, S. Y.; Chun, T. H

    2007-08-15

    The pressure loss test has been accomplished in the test section containing 5x5 rod bundle with a length of 2 m including 3 spacer grids. The test has been performed for the 5 kinds of spacer grids to compare the pressure loss characteristics: 1. Plain spacer grid which has the same body of the Hybrid but without vane (Plain), 2. Hybrid Vane spacer grid (Hybrid), 3. Hybrid-SC spacer grid which is constructed with coined, chamfered strip and is fabricated by spot welding, 4. Hybrid-LC spacer grid which is constructed with coined, chamfered strip and is fabricated by line welding along intersection line, 5. Westinghouse spacer grid with split vane (Plus-7). The pressure loss coefficient of the Plain, Hybrid, Hybrid-SC, Hybrid-LC, and Plus-7 spacer grid is 0.93, 1.15, 1.02, 1.04, and 1.08, respectively.

  18. Influence of blockage effect on measurement by vane anemometers

    Directory of Open Access Journals (Sweden)

    Sluse Jan

    2017-01-01

    Full Text Available The article deals with influence of blockage effect caused by vane anemometer in the wind tunnel by measurement via this anemometer. The influences will be represented by correction coefficient. The first part of this article is focused on the design of the impeller of vane anemometers. The impellers are printed on 3D printer with variable parameters. The anemometer is fixed in an open section of the wind tunnel with closed loop and the velocity profile is measured by Laser Doppler velocimetry (LDV in front and behind it for all impellers. The experimental data are compared with the numerical simulation in OpenFOAM. The results are correction coefficients.

  19. NUMERICAL STUDY OF APPLE COOLING IN TANDEM ARRANGEMENT

    Directory of Open Access Journals (Sweden)

    MARCIO ARÊDES MARTINS

    2011-01-01

    Full Text Available El enfriamiento conjugado de manzanas dispuestas en tándem en bandejas fue estudiado en este trabajo usando una simulación numérica en CFD. Las ecuaciones gobernantes fueron discretizadas y resueltas usando el método de volúmenes fi nitos sobre mallas no estructuradas triangulares, y fue propuesto un esquema de acoplamiento de transferencia de calor entre la parte sólida y fl uida. El modelo computacional fue validado usando el número de Nusselt local y Nusselt promedio que son reportados en la literatura. La variación del numero de Nusselt y de la distribución de temperatura en las manzanas, fueron encontrados debido al comportamiento conjugado del problema. La aproximación conjugada demostró ser una gran herramienta para optimizar correlaciones convectivas de transferencia de calor reportadas en la literatura.

  20. Numerical Analysis and Geometry Optimisation of Vertical Vane of Room Air-conditioner

    Directory of Open Access Journals (Sweden)

    Al-Obaidi Abdulkareem Sh. Mahdi

    2018-01-01

    Full Text Available Vertical vanes of room air-conditioners are used to control and direct cold air. This paper aims to study vertical vane as one of the parameters that affect the efficiency of dissipating cold air to a given space. The vertical vane geometry is analysed and optimised for lower production cost using CFD. The optimised geometry of the vertical vane should have the same or increased efficiency of dissipating cold air and have lesser mass compared to the existing original design. The existing original design of vertical vane is simplified and analysed by using ANSYS Fluent. Efficiency of wind direction is define as how accurate the direction of airflow coming out from vertical vane. In order to calculate the efficiency of wind direction, 15° and 30° rotation of vertical vane inside room air-conditioner are simulated. The efficiency of wind direction for 15° rotation of vertical vane is 57.81% while efficiency of wind direction for 30° rotation of vertical vane is 47.54%. The results of the efficiency of wind direction are used as base reference for parametric study. The parameters investigated for optimisation of vertical vane are focused at length of long span, tip chord and short span. The design of 15% decreased in vane surface area at tip chord is the best optimised design of vertical vane because the efficiency of wind direction is the highest as 60.32%.

  1. Solar updraft power generator with radial and curved vanes

    Science.gov (United States)

    Hafizh, Hadyan; Hamsan, Raziff; Zamri, Aidil Azlan Ahmad; Keprawi, Mohamad Fairuz Mohamad; Shirato, Hiromichi

    2018-02-01

    Solar radiation is the largest source of energy available on earth and the solar updraft power generator (SUPG) is a renewable energy facility capable of harnessing its abundant power. Unlike the conventional wind turbines that harness natural wind in the atmosphere and often encounter with the intermittent issue or even complete cut-off from airflow, the SUPG creates artificial wind as a result of solar-induced convective flows. However, the SUPG has an inherent low total efficiency due to the conversion of thermal energy into pressure energy. Acknowledging the low efficiency and considering its potential as a renewable energy facility, the current work aims to increase the total efficiency by installing a series of guide walls inside the collector. Two types of guide walls were used i.e. radial and curved vanes. The result with curved vanes showed that the updraft velocity is higher compare to those without vanes. About 18% and 64% improvement of updraft velocity and mechanical power were attained respectively. Furthermore, it was observed that the role of radial vanes configuration was more to produce a smooth updraft velocity profile rather than increasing the total efficiency.

  2. Measuring Undrained Shear Strength using CPT and Field Vane

    DEFF Research Database (Denmark)

    Luke, Kirsten

    1992-01-01

    This paper presents the results of CPT's and Field Vane tests from two small test areas with different soils, Glacial Till and Yoldia Clay. An average of Nk = qt/cv for the Yoldia Clay is 7.7 with a standard deviation of 0.7. The average of Nk for the Glacial Till is 9.7 with a standard deviation...

  3. Fluid-structure coupling in the guide vanes cascade of a pump-turbine scale model

    International Nuclear Information System (INIS)

    Roth, S; Hasmatuchi, V; Botero, F; Farhat, M; Avellan, F

    2010-01-01

    The present study concerns fluid-structure coupling phenomena occurring in a guide vane cascade of a pump-turbine scale model placed in the EPFL PF3 test rig. An advanced instrument set is used to monitor both vibrating structures and the surrounding flow. The paper highlights the interaction between vibrating guide vanes and the flow behavior. The pressure fluctuations in the stay vanes region are found to be strongly influenced by the amplitude of the vibrating guide vanes. Moreover, the flow induces different hydrodynamic damping on the vibrating guide vanes depending on the operating point of the pump-turbine.

  4. Fluid-structure coupling in the guide vanes cascade of a pump-turbine scale model

    Science.gov (United States)

    Roth, S.; Hasmatuchi, V.; Botero, F.; Farhat, M.; Avellan, F.

    2010-08-01

    The present study concerns fluid-structure coupling phenomena occurring in a guide vane cascade of a pump-turbine scale model placed in the EPFL PF3 test rig. An advanced instrument set is used to monitor both vibrating structures and the surrounding flow. The paper highlights the interaction between vibrating guide vanes and the flow behavior. The pressure fluctuations in the stay vanes region are found to be strongly influenced by the amplitude of the vibrating guide vanes. Moreover, the flow induces different hydrodynamic damping on the vibrating guide vanes depending on the operating point of the pump-turbine.

  5. Topics in hyperplane arrangements

    CERN Document Server

    Aguiar, Marcelo

    2017-01-01

    This monograph studies the interplay between various algebraic, geometric and combinatorial aspects of real hyperplane arrangements. It provides a careful, organized and unified treatment of several recent developments in the field, and brings forth many new ideas and results. It has two parts, each divided into eight chapters, and five appendices with background material. Part I gives a detailed discussion on faces, flats, chambers, cones, gallery intervals, lunes and other geometric notions associated with arrangements. The Tits monoid plays a central role. Another important object is the category of lunes which generalizes the classical associative operad. Also discussed are the descent and lune identities, distance functions on chambers, and the combinatorics of the braid arrangement and related examples. Part II studies the structure and representation theory of the Tits algebra of an arrangement. It gives a detailed analysis of idempotents and Peirce decompositions, and connects them to the classical th...

  6. CFD analysis for spacer grid mixing vane design

    International Nuclear Information System (INIS)

    Park, Sung-Kew; Kim, Kang-Hoon; Park, Eung-Jun; Jung, Yil-Sup; Suh, Jung-Min; Jeong, Ji-Hun

    2008-01-01

    A computational fluid dynamics (CFD) analysis for a rod bundle with the larger scale model (6x6 array model) has been performed to develop the base shape of mixing vane in accordance with the hydraulic and thermal performance. Explanatory parameters are span pressure drop and span average heat transfer coefficient. The concern related to hot spot is also considered as a subsidiary criterion. Of the several candidates, the final candidate was determined by using the CFD analysis code, STAR-CD. And then, the optimization for it was performed using the response surface method (RSM) that the proper tolerance was considered under the two acceptance criteria such as lower span pressure drop while maintaining the span average heat transfer coefficient with respect to the current shape. The optimized mixing vane shape was verified by the CFD analysis including the effects of allowable tolerance. (author)

  7. Characterization of Rotating Detonation Engine Exhaust Through Nozzle Guide Vanes

    Science.gov (United States)

    2013-03-21

    ENY/13-M09 Abstract A Rotating Detonation Engine ( RDE ) has higher thermal efficiencies in comparison to its traditional gas turbine counterparts. Thus...as budgets decrease and fuel costs increase, RDEs have become a research focus for the United States Air Force. An integration assembly for attaching...the first Nozzle Guide Vane (NGV) section from a T63 gas turbine engine to a 6 inch diameter RDE was designed and built for this study. Pressure

  8. Effect of Guide Vane Clearance Gap on Francis Turbine Performance

    Directory of Open Access Journals (Sweden)

    Ravi Koirala

    2016-04-01

    Full Text Available Francis turbine guide vanes have pivoted support with external control mechanism, for conversion of pressure to kinetic energy and to direct them to runner vanes. This movement along the support is dependent on variation of load and flow (operating conditions. Small clearance gaps between facing plates and the upper and lower guide vane tips are available to aid this movement, through which leakage flow occurs. This secondary flow disturbs the main flow stream, resulting performance loss. Additionally, these increased horseshoe vortex, in presence of sand, when crosses through the gaps, both the surfaces are eroded. This causes further serious effect on performance and structural property by increasing gaps. This paper discusses the observation of the severity in hydropower plants and effect of clearance gaps on general performance of the Francis turbine through computational methods. It also relates the primary result with the empirical relation for leakage flow prediction. Additionally, a possible method to computationally estimate thickness depletion has also been presented. With increasing clearance gap, leakage increases, which lowers energy conversion and turbine efficiency along with larger secondary vortex.

  9. A three dimensional model of a vane rheometer

    International Nuclear Information System (INIS)

    Nazari, Behzad; Moghaddam, Ramin Heidari; Bousfield, Douglas

    2013-01-01

    Highlights: • FEM was used to calculate the isothermal flow parameters in a vane geometry. • Velocity, pressure and then stress fields were obtained. • Using total stress, shaft torque was calculated to compare with experimental data. • A modified cell Reynolds number and power number were used to study flow pattern. • A comparison between 2D and 3D modeling was done based on calculated torques. -- Abstract: Vane type geometries are often used in rheometers to avoid slippage between the sample and the fixtures. While yield stress and other rheological properties can be obtained with this geometry, a complete analysis of this complex flow field is lacking in the literature. In this work, a finite element method is used to calculate the isothermal flow parameters in a vane geometry. The method solves the mass and momentum continuity equations to obtain velocity, pressure and then stress fields. Using the total stress numerical data, we calculated the torque applied on solid surfaces. The validity of the computational model was established by comparing the results to experimental results of shaft torque at different angular velocities. The conditions where inertial terms become important and the linear relationship between torque and stress are quantified with dimensionless groups. The accuracy of a two dimensional analysis is compared to the three dimensional results

  10. National arrangements for radiotherapy

    International Nuclear Information System (INIS)

    2007-01-01

    After a presentation of several letters exchanged between the French health ministry and public agencies in charge of public health or nuclear safety after a radiotherapy accident in Epinal, this report comments the evolution of needs in cancerology care and the place given to radiotherapy. It outlines the technological and organisational evolution of radiotherapy and presents the distribution of radiotherapy equipment, of radio-therapists and other radiotherapy professionals in France. Within the context of radiotherapy accidents which occurred in 2007, it presents the regulatory arrangements which aimed at improving the safety, short term and middle term arrangements which are needed to support and structure radiotherapy practice quality. It stresses the fact that the system will deeply evolve by implementing a radiotherapy vigilance arrangement and a permanent follow-on and adaptation plan based on surveys and the creation of a national committee

  11. Nuclear reactor internals arrangement

    International Nuclear Information System (INIS)

    Frisch, E.; Andrews, H.N.

    1976-01-01

    A nuclear reactor internals arrangement is disclosed which facilitates reactor refueling. A reactor vessel and a nuclear core is utilized in conjunction with an upper core support arrangement having means for storing withdrawn control rods therein. The upper core support is mounted to the underside of the reactor vessel closure head so that upon withdrawal of the control rods into the upper core support, the closure head, the upper core support and the control rods are removed as a single unit thereby directly exposing the core for purposes of refueling

  12. Rotary kiln arrangements

    International Nuclear Information System (INIS)

    Hayes, M.R.

    1983-01-01

    In a rotary kiln arrangement in which a reaction is to occur between counterflowing reactants and material is discharged through a hopper, an injector for at least one reactant extends into a reaction zone of the kiln, means being provided for the reaction zone to be maintained within a desired temperature range. The said means includes heating elements for adjusting the temperature of the injected reactant to a temperature within the desired range while it is in the injector. The arrangement may be used in the production of uranium oxides from uranium hexafluoride. (author)

  13. Best connected rectangular arrangements

    Directory of Open Access Journals (Sweden)

    Krishnendra Shekhawat

    2016-03-01

    Full Text Available It can be found quite often in the literature that many well-known architects have employed either the golden rectangle or the Fibonacci rectangle in their works. On contrary, it is rare to find any specific reason for using them so often. Recently, Shekhawat (2015 proved that the golden rectangle and the Fibonacci rectangle are one of the best connected rectangular arrangements and this may be one of the reasons for their high presence in architectural designs. In this work we present an algorithm that generates n-4 best connected rectangular arrangements so that the proposed solutions can be further used by architects for their designs.

  14. Experimental Study on Series Operation of Sliding Vane Pump and Centrifugal Pump

    OpenAIRE

    Li, Tao; Zhang, Weiming; Jiang, Ming; Li, Zhengyang

    2013-01-01

    A platform for sliding vane pump and centrifugal pump tests is installed to study the series operation of them under different characteristics of pipeline. Firstly, the sliding vane pump and the centrifugal pump work independently, and the performance is recorded. Then, the two types of pumps are combined together, with the sliding vane pump acting as the feeding pump. Comparison is made between the performance of the independently working pump and the performance of series operation pump. Re...

  15. Numerical Analysis of a Centrifugal Fan for Improved Performance using Splitter Vanes

    OpenAIRE

    N. Yagnesh Sharma; K. Vasudeva Karanth

    2009-01-01

    The flow field in a centrifugal fan is highly complex with flow reversal taking place on the suction side of impeller and diffuser vanes. Generally performance of the centrifugal fan could be enhanced by judiciously introducing splitter vanes so as to improve the diffusion process. An extensive numerical whole field analysis on the effect of splitter vanes placed in discrete regions of suspected separation points is possible using CFD. This paper examines the effect of sp...

  16. Water table tests of proposed heat transfer tunnels for small turbine vanes

    Science.gov (United States)

    Meitner, P. L.

    1974-01-01

    Water-table flow tests were conducted for proposed heat-transfer tunnels which were designed to provide uniform flow into their respective test sections of a single core engine turbine vane and a full annular ring of helicopter turbine vanes. Water-table tests were also performed for the single-vane test section of the core engine tunnel. The flow in the heat-transfer tunnels was shown to be acceptable.

  17. Experimental comparison of the optical measurements of a cross-flow in a rod bundle with mixing vanes

    International Nuclear Information System (INIS)

    Chang, Seok Kyu; Choo, Yeon Jun; Kim, Bok Deuk; Song, Chul Hwa

    2008-01-01

    The lateral crossflow on subchannels in a rod bundle array was investigated to understand the flow characteristics related to the mixing vane types on a spacer grid by using the PIV technique. For more measurement resolutions, a 5x5 rod bundle was fabricated a 2.6 times larger than the real rod bundle size in a pressurized water reactor. A rod-embedded optic array was specially designed and used for the illumination of the inner subchannels. The crossflow field in a subchannel was characterized by the type and the arrangement of the mixing vanes. At a near downstream location from the spacer grid (z/D h =1) in the case of the split type, a couple of small vortices were generated diagonally in a subchannel. On the other hand, in the case of the swirl type, there was a large elliptic vortex generated in the center of a subchannel. The measurement results were compared with the experimental results which had been performed with the LDV technique at the same test facility. The magnitudes of the flow velocity and the vorticity in PIV results were less than those in LDV measurement results. It was shown that the instantaneous flow fields in a subchannel frequently have quite different shapes from the averaged one

  18. Theoretical morphology and development of flight feather vane asymmetry with experimental tests in parrots.

    Science.gov (United States)

    Feo, Teresa J; Prum, Richard O

    2014-06-01

    Asymmetry in flight feather vane width is a major functional innovation associated with the evolution of flight in the ancestors of birds. However, the developmental and morphological basis of feather shape is not simple, and the developmental processes involved in vane width asymmetry are poorly understood. We present a theoretical model of feather morphology and development that describes the possible ways to modify feather development and produce vane asymmetry. Our model finds that the theoretical morphospace of feather shape is redundant, and that many different combinations of parameters could be responsible for vane asymmetry in a given feather. Next, we empirically measured morphological and developmental model parameters in asymmetric and symmetric feathers from two species of parrots to identify which combinations of parameters create vane asymmetry in real feathers. We found that both longer barbs, and larger barb angles in the relatively wider trailing vane drove asymmetry in tail feathers. Developmentally, longer barbs were the result of an offset of the radial position of the new barb locus, whereas larger barb angles were produced by differential expansion of barbs as the feather unfurls from the tubular feather germ. In contrast, the helical angle of barb ridge development did not contribute to vane asymmetry and could be indicative of a constraint. This research provides the first comprehensive description of both the morphological and developmental modifications responsible for vane asymmetry within real feathers, and identifies key steps that must have occurred during the evolution of vane asymmetry. © 2014 Wiley Periodicals, Inc.

  19. Numerical analysis and experiment research on fluid orbital performance of vane type propellant management device

    International Nuclear Information System (INIS)

    Hu, Q; Li, Y; Pan, H L; Liu, J T; Zhuang, B T

    2015-01-01

    Vane type propellant management device (PMD) is one of the key components of the vane-type surface tension tank (STT), and its fluid orbital performance directly determines the STT's success or failure. In present paper, numerical analysis and microgravity experiment study on fluid orbital performance of a vane type PMD were carried out. By using two-phase flow model of volume of fluid (VOF), fluid flow characteristics in the tank with the vane type PMD were numerically calculated, and the rules of fluid transfer and distribution were gotten. A abbreviate model test system of the vane type PMD is established and microgravity drop tower tests were performed, then fluid management and transmission rules of the vane type PMD were obtained under microgravity environment. The analysis and tests results show that the vane type PMD has good and initiative fluid orbital management ability and meets the demands of fluid orbital extrusion in the vane type STT. The results offer valuable guidance for the design and optimization of the new generation of vane type PMD, and also provide a new approach for fluid management and control in space environment

  20. Experimental hot-wire measurements in a centrifugal compressor with vaned diffuser

    International Nuclear Information System (INIS)

    Pinarbasi, Ali

    2008-01-01

    The purpose of this study was to improve the understanding of the flow physics in a centrifugal compressor with vaned diffuser. For this reason three component hot wire measurements in the vaneless space and vane region of a low speed centrifugal compressor are presented. A low speed compressor with a 19 bladed backswept impeller and diffuser with 16 wedge vanes were used. The measurements were made at three inter-vane positions and are presented as mean velocity, turbulent kinetic energy and flow angle distributions. The flow entering the diffuser closely resembles the classic jet-wake flow characteristic of centrifugal impeller discharges. A strong upstream influence of the diffuser vanes is observed which results in significant variations in flow quantities between the vane-to-vane locations. The circumferential variations due to the passage and blade wakes rapidly mix out in the vaneless space, although some variations are still discernible in the vaned region. The impeller blade wakes mix out rapidly within the vaneless space and more rapidly than in an equivalent vaneless diffuser. Although the flow is highly non uniform in velocity at the impeller exit, there is no evidence in the results of any separation from the diffuser vanes

  1. A Straight-bladed Vertical Axis Wind Turbine with a Directed Guide Vane Row-Effect of Guide Vane Geometry on the Performance-

    Institute of Scientific and Technical Information of China (English)

    Manabu TAKAO; Hideki KUMA; Takao MAEDA; Yasunari KAMADA; Michiaki OKI; Atsushi MINODA

    2009-01-01

    The objective of this study is to show the effect of guide vane geometry on the performance. In order to over-come the disadvantages of vertical axis wind turbine, a straight-bladed vertical axis wind turbine (S-VAWT) with a directed guide vane row has been proposed and tested by the authors. According to previous studies, it was clarified that the performance of the turbine can be improved by means of the directed guide vane row. However, the guide vane geometry of S-VAWT has not been optimized so far. In order to clarify the effect of guide vane geometry, the effects of setting angle and gap between rotor blade and guide vane on power coefficient and start-ing characteristic were investigated in the experiments. The experimental study of the proposed wind turbine was carded out by a wind tunnel. The wind tunnel with a diameter of 1.8m is open jet type. The wind velocity is 8 m/s in the experiments. The rotor has three straight blades with a profile of NACA0018 and a chord length of 100 mm, a diameter of 0.6 m and a blade height of 0.7 m. The guide vane row consists of 3 arc plates.

  2. Imaging arrangement and microscope

    Science.gov (United States)

    Pertsinidis, Alexandros; Chu, Steven

    2015-12-15

    An embodiment of the present invention is an imaging arrangement that includes imaging optics, a fiducial light source, and a control system. In operation, the imaging optics separate light into first and second tight by wavelength and project the first and second light onto first and second areas within first and second detector regions, respectively. The imaging optics separate fiducial light from the fiducial light source into first and second fiducial light and project the first and second fiducial light onto third and fourth areas within the first and second detector regions, respectively. The control system adjusts alignment of the imaging optics so that the first and second fiducial light projected onto the first and second detector regions maintain relatively constant positions within the first and second detector regions, respectively. Another embodiment of the present invention is a microscope that includes the imaging arrangement.

  3. Cable support arrangements

    International Nuclear Information System (INIS)

    Pendleton, E.; Murray, A.

    1983-01-01

    A cable support arrangement extending from a refuelling level floor of a nuclear reactor to the inner shield of a double rotatable shield comprises a linearly extensible cable support and disciplining boom, reaching from the floor to the main shield, and a circumferentially extensible cable support and disciplining means running from the end of the boom to a fixed end on the inner shield. (author)

  4. Numerical Study of the Rib Arrangements for Enhancing Heat Transfer in a Two-pass Channel of Large Aspect Ratio

    Energy Technology Data Exchange (ETDEWEB)

    Han, Sol; Choi, Seok Min; Sohn, Ho-Seong; Cho, Hyung Hee [Yonsei Univ., Seoul (Korea, Republic of)

    2017-03-15

    The present study investigated the effect of the rib arrangement and a guide vane for enhancing internal cooling of the blade. Two types of rib arrangements were used in the first and second passage in parallel. Aspect ratio of the channel was 5 and a fixed Reynolds number based on hydraulic diameter was 10,000. The attack angle of rib was 60°, rib pitch-to-height ratio (p/e) was 10, and the rib height-to-hydraulic-diameter ratio (e/D{sub n}) was 0.075. The effect of an interaction between Dean vortices and the secondary vortices from the first passage was observed. Overall, the attack angle of rib in the first passage was dominant factor to heat transfer and flow patterns in turning region. Also, the channel with a guide vane showed enhanced heat transfer at the tip surface with reducing flow separation and recirculation.

  5. The Analysis for the Effect of Mixing Vane Shape on TDC

    International Nuclear Information System (INIS)

    Moon, Kang Hoon; Park, Ho Young; Kim, Kang Hoon; Park, Eung Jun; Suh, Jung Min

    2011-01-01

    The Thermal Diffusion Coefficient (TDC) is an input parameter to subchannel code, and it is required to predict local flow conditions in a PWR fuel bundle. TDC influences on the prediction of thermal interchange or mixing of thermal energy between the hot subchannel and interconnected adjacent subchannels. The thermal mixing term in the energy equation is generally represented in terms of a non-dimensional inverse Peclet number or TDC. The parameters associated with thermal mixing can be defined as Eq.(1): TDC =Pe x De/a (1) where: Pe : Inverse Peclet Number (dimensionless) = ε/ Va De : Equivalent hydraulic diameter, in. a : Lateral flow area between channels per unit length, in 2 /in ε : Mixing coefficient, in 2 /sec V : Velocity, in/sec TDC is an important factor to evaluate thermal performance. So, flow temperature maps were obtained from the 5x5 rod bundle test section to assess the thermal performance of corresponding fuels. The flow temperatures were measured by thermocouple at the end of heated length and the centroid of subchannel. There are two typical methods to arrange the hot and cold fuel rods as shown in Fig. 1. Configuration Fig. 1(b) is adopted in this work. This paper presents how to determine the TDC and verifies whether all TDC with the effect of mixing vane shape is valid with respect to current design value

  6. On the Relativistic Correction of Particles Trajectory in Tandem Type Electrostatic Accelerator

    OpenAIRE

    Minárik Stanislav

    2015-01-01

    A constant potential is applied to the acceleration of the ion-beam in the tandem type electrostatic accelerator. However, not just one voltage is applied, but instead a number of applications can be made in succession by means of the tandem arrangement of high voltage tubes. This number of voltage applications, which is the number of so-called "stages" of a tandem accelerator, may be two, three, or four, depending on the chosen design. Electrostatic field with approximately constant intensit...

  7. Inspection of Emergency Arrangements

    International Nuclear Information System (INIS)

    2013-01-01

    The Working Group on Inspection Practices (WGIP) was tasked by the NEA CNRA to examine and evaluate the extent to which emergency arrangements are inspected and to identify areas of importance for the development of good inspection practices. WGIP members shared their approaches to the inspection of emergency arrangements by the use of questionnaires, which were developed from the requirements set out in IAEA Safety Standards. Detailed responses to the questionnaires from WGIP member countries have been compiled and are presented in the appendix to this report. The following commendable practices have been drawn from the completed questionnaires and views provided by WGIP members: - RBs and their Inspectors have sufficient knowledge and information regarding operator's arrangements for the preparedness and response to nuclear emergencies, to enable authoritative advice to be given to the national coordinating authority, where necessary. - Inspectors check that the operator's response to a nuclear emergency is adequately integrated with relevant response organisations. - Inspectors pay attention to consider the integration of the operator's response to safety and security threats. - The efficiency of international relations is checked in depth during some exercises (e.g. early warning, assistance and technical information), especially for near-border facilities that could lead to an emergency response abroad. - RB inspection programmes consider the adequacy of arrangements for emergency preparedness and response to multi-unit accidents. - RBs assess the adequacy of arrangements to respond to accidents in other countries. - The RB's role is adequately documented and communicated to all agencies taking part in the response to a nuclear or radiological emergency. - Inspectors check that threat assessments for NPPs have been undertaken in accordance with national requirements and that up-to-date assessments have been used as the basis for developing emergency plans for

  8. The Screw-Conveyor Vane Design for Piece-Wise Construction ...

    African Journals Online (AJOL)

    Such a method of manufacture is beyond the resources of a general-purpose metal workshop that may require the odd spiral vane once in a while and can neither afford the time nor the cost of ordering from abroad. In this article the method of six blanks which the author has developed for the building up of the vane ...

  9. Steam generator arrangement

    International Nuclear Information System (INIS)

    Ssinegurski, E.

    1981-01-01

    A steam flow path arrangement for covering the walls of the rear gas pass of a steam generator is disclosed. The entire flow passes down the sidewalls with a minor portion then passing up through the rear wall to a superheater inlet header at an intermediate elevation. The major portion of the flow passes up the front wall and through hanger tubes to a roof header. From there the major portion passes across the roof and down the rear wall to the superheater inlet header at the intermediate elevation

  10. Large tandem accelerators

    International Nuclear Information System (INIS)

    Jones, C.M.

    1976-01-01

    The increasing importance of energetic heavy ion beams in the study of atomic physics, nuclear physics, and materials science has partially or wholly motivated the construction of a new generation of tandem accelerators designed to operate at maximum terminal potentials in the range 14 to 30 MV. In addition, a number of older tandem accelerators are now being significantly upgraded to improve their heavy ion performance. Both of these developments have reemphasized the importance of negative heavy ion sources. The new large tandem accelerators are described, and the requirements placed on negative heavy ion source technology by these and other tandem accelerators used for the acceleration of heavy ions are discussed. First, a brief description is given of the large tandem accelerators which have been completed recently, are under construction, or are funded for construction, second, the motivation for construction of these accelerators is discussed, and last, criteria for negative ion sources for use with these accelerators are presented

  11. Research and development on the hydraulic design system of the guide vanes of multistage centrifugal pumps

    International Nuclear Information System (INIS)

    Zhang, Q H; Xu, Y; Shi, W D; Lu, W G

    2012-01-01

    To improve the hydraulic design accuracy and efficiency of the guide vanes of the multistage centrifugal pumps, four different-structured guide vanes are investigated, and the design processes of those systems are established. The secondary development platforms of the ObjectArx2000 and the UG/NX OPEN are utilized to develop the hydraulic design systems of the guide vanes. The error triangle method is adopted to calculate the coordinates of the vanes, the profiles of the vanes are constructed by Bezier curves, and then the curves of the flow areas along the flow-path are calculated. Two-dimensional and three-dimensional hydraulic models can be developed by this system.

  12. Study and Control of a Radial Vaned Diffuser Stall

    Directory of Open Access Journals (Sweden)

    Aurélien Marsan

    2012-01-01

    Full Text Available The aim of the present study is to evaluate the efficiency of a boundary layer suction technique in case of a centrifugal compressor stage in order to extend its stable operating range. First, an analysis of the flow pattern within the radial vaned diffuser is presented. It highlights the stall of the diffuser vanes when reaching a low massflow. A boundary layer separation in the hub-suction side corner grows when decreasing the massflow from the nominal operating point to the surge and finally leads to a massive stall. An aspiration strategy is investigated in order to control the stall. The suction slot is put in the vicinity of the saddle that originates the main separating skin-friction line, identified thanks to the analysis of the skin-friction pattern. Several aspiration massflow rates are tested, and two different modelings of the aspiration are evaluated. Finally, an efficient control is reached with a removal of only 0,1% of the global massflow and leads—from a steady-state calculations point of view—to an increase by 40% of the compressor operating range extent.

  13. Port entry arrangements

    International Nuclear Information System (INIS)

    Chicken, J.C.; King, M.A.

    1978-01-01

    The objective of the paper is to describe the safety scheme port authorities should establish to deal with any contingency that may result from the visit of a nuclear powered ship. The safety scheme should be devised to cover both normal operation and any accident conditions that could arise while the ship is in port. The paper is divided into three parts. The three parts being: background information, general instructions, and emergency procedures. The background information will describe the nature of the hazards a port authority has to be prepared to deal with, and the philosophical basis for a berthing policy. In the part dealing with general instructions the objective of the safety scheme will be described. Also this part will describe the composition of the Port Safety Panel, allocation of responsibilities, passage and berthing arrangements, general safety precautions, records required, and rescue arrangements. In the part dealing with emergency procedures the role of: the Ship's Master, Harbour Authorities, Local Police, and local Health Services are discussed. As an Appendix to the paper a copy of the safety scheme that has been devised for visits of nuclear merchant ships to Southampton is given

  14. Suppression of tonal noise in a centrifugal fan using guide vanes

    Science.gov (United States)

    Paramasivam, Kishokanna; Rajoo, Srithar; Romagnoli, Alessandro

    2015-11-01

    This paper presents the work aiming for tonal noise reduction in a centrifugal fan. In previous studies, it is well documented that tonal noise is the dominant noise source generated in centrifugal fans. Tonal noise is generated due to the aerodynamic interaction between the rotating impeller and stationary diffuser vanes. The generation of tonal noise is related to the pressure fluctuation at the leading edge of the stationary vane. The tonal noise is periodic in time which occurs at the blade passing frequency (BPF) and its harmonics. Much of previous studies, have shown that the stationary vane causes the tonal noise and generation of non-rotational turbulent noise. However, omitting stationary vanes will lead to the increase of non-rotational turbulent noise resulted from the high velocity of the flow leaving the impeller. Hence in order to reduce the tonal noise and the non-rotational noise, guide vanes were designed as part of this study to replace the diffuser vanes, which were originally used in the chosen centrifugal fan. The leading edge of the guide vane is tapered. This modification reduces the strength of pressure fluctuation resulting from the interaction between the impeller outflow and stationary vane. The sound pressure level at blade passing frequency (BPF) is reduced by 6.8 dB, the 2nd BPF is reduced by 4.1 dB and the 3rd BPF reduced by about 17.5 dB. The overall reduction was 0.9 dB. The centrifugal fan with tapered guide vanes radiates lower tonal noise compared to the existing diffuser vanes. These reductions are achieved without compromising the performance of the centrifugal fan. The behavior of the fluid flow was studied using computational fluid dynamics (CFD) tools and the acoustics characteristics were determined through experiments in an anechoic chamber.

  15. Power distribution arrangement

    DEFF Research Database (Denmark)

    2010-01-01

    An arrangement and a method for distributing power supplied by a power source to two or more of loads (e.g., electrical vehicular systems) is disclosed, where a representation of the power taken by a particular one of the loads from the source is measured. The measured representation of the amount...... of power taken from the source by the particular one of the loads is compared to a threshold to provide an overload signal in the event the representation exceeds the threshold. Control signals dependant on the occurring of the overload signal are provided such that the control signal decreases the output...... power of the power circuit in case the overload signal occurs...

  16. Thermally actuated linkage arrangement

    International Nuclear Information System (INIS)

    Anderson, P.M.

    1981-01-01

    A reusable thermally actuated linkage arrangement includes a first link member having a longitudinal bore therein adapted to receive at least a portion of a second link member therein, the first and second members being sized to effect an interference fit preventing relative movement there-between at a temperature below a predetermined temperature. The link members have different coefficients of thermal expansion so that when the linkage is selectively heated by heating element to a temperature above the predetermined temperature, relative longitudinal and/or rotational movement between the first and second link members is enabled. Two embodiments of a thermally activated linkage are disclosed which find particular application in actuators for a grapple head positioning arm in a nuclear reactor fuel handling mechanism to facilitate back-up safety retraction of the grapple head independently from the primary fuel handling mechanism drive system. (author)

  17. Inductive circuit arrangements

    International Nuclear Information System (INIS)

    Mansfield, Peter; Coxon, R.J.

    1987-01-01

    A switched coil arrangement is connected in a bridge configuration of four switches S 1 , S 2 , S 3 and S 4 which are each shunted by diodes D 1 , D 2 , D 3 and D 4 so that current can flow in either direction through a coil L depending on the setting of the switches. A capacitor C is connected across the bridge through a switch S 5 to receive the inductive energy stored in coil L on breaking the current flow path through the coil. The electrostatic energy stored in capacitor C can then be used to supply current through the coil in the reverse direction either immediately or after a time delay. Coil L may be a superconductive coil. Losses in the circuit can be made up by a trickle charge of capacitor C from a separate supply V 2 . The device may be used in nuclear magnetic resonance imaging. (author)

  18. Camshaft bearing arrangement

    Energy Technology Data Exchange (ETDEWEB)

    Aoi, K.; Ozawa, T.

    1986-06-10

    A bearing arrangement is described for the camshaft of an internal combustion engine or the like which camshaft is formed along its length in axial order with a first bearing surface, a first cam lobe, a second bearing surface, a second cam lobe, a third bearing surface, a third cam lobe and a fourth bearing surface, the improvement comprising first bearing means extending around substantially the full circumference of the first bearing surface and journaling the first bearing surface, second bearing means extending around substantially less than the circumference of the second bearing surface and journaling the second bearing surface, third bearing means extending around substantially less than the circumference of the third bearing surface and journaling the third bearing surface, and fourth bearing means extending around substantially the full circumference of the fourth bearing surface and journaling the first bearing surface.

  19. Hot spot detection system for vanes or blades of a combustion turbine

    Science.gov (United States)

    Twerdochlib, M.

    1999-02-02

    This invention includes a detection system that can determine if a turbine component, such as a turbine vane or blade, has exceeded a critical temperature, such as a melting point, along any point along the entire surface of the vane or blade. This system can be employed in a conventional combustion turbine having a compressor, a combustor and a turbine section. Included within this system is a chemical coating disposed along the entire interior surface of a vane or blade and a closed loop cooling system that circulates a coolant through the interior of the vane or blade. If the temperature of the vane or blade exceeds a critical temperature, the chemical coating will be expelled from the vane or blade into the coolant. Since while traversing the closed loop cooling system the coolant passes through a detector, the presence of the chemical coating in the coolant will be sensed by the system. If the chemical coating is detected, this indicates that the vane or blade has exceeded a critical temperature. 5 figs.

  20. Interaction of impeller and guide vane in a series-designed axial-flow pump

    International Nuclear Information System (INIS)

    Kim, S; Choi, Y S; Lee, K Y; Kim, J H

    2012-01-01

    In this paper, the interaction of the impeller and guide vane in a series-designed axial-flow pump was examined through the implementation of a commercial CFD code. The impeller series design refers to the general design procedure of the base impeller shape which must satisfy the various flow rate and head requirements by changing the impeller setting angle and number of blades of the base impeller. An arc type meridional shape was used to keep the meridional shape of the hub and shroud with various impeller setting angles. The blade angle and the thickness distribution of the impeller were designed as an NACA airfoil type. In the design of the guide vane, it was necessary to consider the outlet flow condition of the impeller with the given setting angle. The meridional shape of the guide vane were designed taking into consideration the setting angle of the impeller, and the blade angle distribution of the guide vane was determined with a traditional design method using vane plane development. In order to achieve the optimum impeller design and guide vane, three-dimensional computational fluid dynamics and the DOE method were applied. The interaction between the impeller and guide vane with different combination set of impeller setting angles and number of impeller blades was addressed by analyzing the flow field of the computational results.

  1. Design and Analysis of a Split Deswirl Vane in a Two-Stage Refrigeration Centrifugal Compressor

    Directory of Open Access Journals (Sweden)

    Jeng-Min Huang

    2014-09-01

    Full Text Available This study numerically investigated the influence of using the second row of a double-row deswirl vane as the inlet guide vane of the second stage on the performance of the first stage in a two-stage refrigeration centrifugal compressor. The working fluid was R134a, and the turbulence model was the Spalart-Allmaras model. The parameters discussed included the cutting position of the deswirl vane, the staggered angle of two rows of vane, and the rotation angle of the second row. The results showed that the performance of staggered angle 7.5° was better than that of 15° or 22.5°. When the staggered angle was 7.5°, the performance of cutting at 1/3 and 1/2 of the original deswirl vane length was slightly different from that of the original vane but obviously better than that of cutting at 2/3. When the staggered angle was 15°, the cutting position influenced the performance slightly. At a low flow rate prone to surge, when the second row at a staggered angle 7.5° cutting at the half of vane rotated 10°, the efficiency was reduced by only about 0.6%, and 10% of the swirl remained as the preswirl of the second stage, which is generally better than other designs.

  2. Turbine blade and vane heat flux sensor development, phase 2

    Science.gov (United States)

    Atkinson, W. H.; Cyr, M. A.; Strange, R. R.

    1985-01-01

    The development of heat flux sensors for gas turbine blades and vanes and the demonstration of heat transfer measurement methods are reported. The performance of the heat flux sensors was evaluated in a cylinder in cross flow experiment and compared with two other heat flux measurement methods, the slug calorimeter and a dynamic method based on fluctuating gas and surface temperature. Two cylinders, each instrumented with an embedded thermocouple sensor, a Gardon gauge, and a slug calorimeter, were fabricated. Each sensor type was calibrated using a quartz lamp bank facility. The instrumented cylinders were then tested in an atmospheric pressure combustor rig at conditions up to gas stream temperatures of 1700K and velocities to Mach 0.74. The test data are compared to other measurements and analytical prediction.

  3. LOX/LH2 vane pump for auxiliary propulsion systems

    Science.gov (United States)

    Hemminger, J. A.; Ulbricht, T. E.

    1985-01-01

    Positive displacement pumps offer potential efficiency advantages over centrifugal pumps for future low thrust space missions. Low flow rate applications, such as space station auxiliary propulsion or dedicated low thrust orbiter transfer vehicles, are typical of missions where low flow and high head rise challenge centrifugal pumps. The positive displacement vane pump for pumping of LOX and LH2 is investigated. This effort has included: (1) a testing program in which pump performance was investigated for differing pump clearances and for differing pump materials while pumping LN2, LOX, and LH2; and (2) an analysis effort, in which a comprehensive pump performance analysis computer code was developed and exercised. An overview of the theoretical framework of the performance analysis computer code is presented, along with a summary of analysis results. Experimental results are presented for pump operating in liquid nitrogen. Included are data on the effects on pump performance of pump clearance, speed, and pressure rise. Pump suction performance is also presented.

  4. On development of RFQ vanes from beam dynamics data

    International Nuclear Information System (INIS)

    Chatterjee, Avik; Padhi, Rakesh; Banerjee, M.K.; Naik, Vaishali; Sanyal, Dirtha; Choudhury, Siddhartha De; Chakrabarti, Alok

    2005-01-01

    Simulation at critical steps of product development greatly helps to detect the design flaws at the earlier stage and gives a digital platform to iterate the design and process at the initial stage. This helps to reduce the risk of failure considerably and gives an alternative to reduce the number of physical prototypes for design validation. Modern concepts of virtual prototyping for predicting functional behaviour of a product and process are gaining momentum globally as it is the fully integrated approach to converge the concepts of functional design, Design for Manufacturing (DFM), Design for Assembly (DFA) and manufacturing process simulation. This concept has been partially implemented in development of RFQ (Radio Frequency Quadruple) vanes and the basic guidelines have been discussed. (author)

  5. Thermal modelling of a dry revolving vane compressor

    Science.gov (United States)

    Ooi, K. T.; Aw, K. T.

    2017-08-01

    The lubricant used in compressors serves to lubricate, to seal the gaps to reduce internal leakage and to a certain extent, to cool. However, a lubricant free compressor is attractive if lubricants become a source of contaminant, or in areas where the compressor needs be placed under any orientation, such as those in military or portable computing. In this paper, a thermal model for a dry revolving vane compressor is presented. This thermal model sets out to predict the steady-state operating temperatures of the compressor components. The lumped thermal conductance method was employed. The results of the components temperature will be presented and discussed. A high potential for overheating is observed at the shaft bearings.

  6. Study on Orbital Liquid Transport and Interface Behavior in Vane Tank

    Science.gov (United States)

    Kang, Qi; Rui, Wei

    2016-07-01

    Liquid propellant tank is used to supply gas free liquid for spacecraft as an important part of propulsion system. The liquid behavior dominated by surface tension in microgravity is obviously different with that on the ground, which put forward a new challenge to the liquid transport and relocation. The experiments which are investigated at drop tower in National Microgravity Lab have concentrated on liquid relocation following thruster firing. Considered that the liquid located at the bottom in the direction of the acceleration vector, a sphere scale vane tank is used to study the liquid-gas interface behaviors with different acceleration vector and different filling independently and we obtain a series of stable equilibrium interface and relocation time. We find that there is an obvious sedimentation in the direction of acceleration vector when fill rate greater than 2% fill. Suggestions have been put forward that outer vanes transferring liquid to the outlet should be fixed and small holes should be dogged at the vane close to the center post to improve the liquid flow between different vanes when B0 is greater than 2.5. The research about liquid transport alone ribbon vanes is simulated though software Flow3D. The simulation process is verified by comparing the liquid lip and vapor-liquid interface obtained from drop tower experiment and simulation result when fill rate is 15%. Then the influence of fill rate, numbers of vanes and the gap between vane and wall is studied through the same simulate process. Vanes' configurations are also changed to study the effect on the lip and liquid volume below some section. Some suggestions are put forward for the design of vanes.

  7. Testing of Composite Fan Vanes With Erosion-Resistant Coating Accelerated

    Science.gov (United States)

    Bowman, Cheryl L.; Sutter, James K.; Otten, Kim D.; Samorezov, Sergey; Perusek, Gail P.

    2004-01-01

    The high-cycle fatigue of composite stator vanes provided an accelerated life-state prior to insertion in a test stand engine. The accelerated testing was performed in the Structural Dynamics Laboratory at the NASA Glenn Research Center under the guidance of Structural Mechanics and Dynamics Branch personnel. Previous research on fixturing and test procedures developed at Glenn determined that engine vibratory conditions could be simulated for polymer matrix composite vanes by using the excitation of a combined slip table and electrodynamic shaker in Glenn's Structural Dynamics Laboratory. Bench-top testing gave researchers the confidence to test the coated vanes in a full-scale engine test.

  8. Vane fabrication for the proof-of-principle radio-frequency quadrupole accelerator

    International Nuclear Information System (INIS)

    Williams, S.W.; Potter, J.M.

    1981-01-01

    The electrodes for the Proof-of-Principle (POP) Radio-Frequency Quadrupole (RFQ) accelerator were machined on a numerically controlled, three-axis, vertical mill. These pole tips, or vanes, were prepared for, and used, in the successful demonstration of RFQ practicality at Los Alamos National Laboratory in February 1980. The data set that described the vanes contained about 10 million bits of tool position data. The vanes were cut from OFHC copper blanks. The tolerances achieved were approximately +- 0.005 cm. The design and manufacturing procedures are described

  9. Powerful Swirl Generation of Flow-driven Rotating Mixing Vane for Enhancing CHF

    International Nuclear Information System (INIS)

    Seo, Han; Seo, Seok Bin; Heo, Hyo; Bang, In Cheol

    2014-01-01

    Mixing vanes are utilized to improve CHF and heat transfer performance in the rod bundle during normal operation. Experimental measurement of the swirling flow from a split vane pair was conducted using particle image velocimetry (PIV) and boroscope. The lateral velocity fields show that the swirling flow was initially centered in the subchannel and the computational fluid dynamics (CFD) analysis was performed based on the experiment. To visualize flow patterns in the 5Χ5 subchannel using PIV, matching the refraction between the working fluid and the structure was considered and the experiment aimed to develop the experimental data for providing fundamental information of the CFD analysis. The fixed split vane is the main mixing inducer in the fuel assembly. In a heat exchanger research, propeller type swirl generates at several pitch ratios and different blades angles were used to enhance heat transfer rate. Significant improvements of the heat transfer rate using the propellers were confirmed due to creation of tangential flow. In the present study, the mixing effect of rotation vane which has a shape of propeller was studied using PIV. A split vane was considered in the experiment to show the effect of rotation vane. Vertical and horizontal flow analyses were conducted to show the possible use of rotation vane in a subchannel. In the present work, the study of flow visualization using three types of vanes is conducted to show the mixing effect. The vertical flow and the horizontal flow distributions were analyzed in the two experimental facilities. For the vertical flow facility, flow distributions, flow profiles, and the turbulence kinetic energy are analyzed at the centerline of the channel. The results show that the rotation vane has the highest flow and turbulence kinetic intensity at the centerline of the channel. For the horizontal flow facility, the results indicate that lateral flow of the rotation vane is generated and maintained along with the flow

  10. High frequency ignition arrangement

    Energy Technology Data Exchange (ETDEWEB)

    Canup, R E

    1977-03-03

    The invention concerns an HF ignition arrangement for combustion engines with a transistor oscillator. As this oscillator requires a current of 10A, with peak currents up to about 50A, it is not sensible to take this current through the remote ignition switch for switching it on and off. According to the invention the HF high voltage transformer of the ignition is provided with a control winding, which only requires a few milliamps DC and which can therefore be switched via the ignition switch. If the ignition switch is in the 'running' position, then a premagnetising DC current flows through the control winding, which suppresses the oscillation of the oscillator which has current flowing through it, until this current is interrupted by the interruptor contacts controlled by the combustion engine, so that the oscillations of the oscillator start immediately; the oscillator only continues to oscillate during the period during which the interruptor contacts controlled by the machine are open and interrupt the premagnetisation current. The control winding is short circuited in the 'off' position of the ignition switch.

  11. Suction Side Roughness Effects on Film Cooling Heat Transfer on a Turbine Vane

    National Research Council Canada - National Science Library

    Rutledge, James

    2004-01-01

    An experimental study was conducted in a simulated three vane linear cascade to determine the effects of surface roughness and film cooling on the heat transfer coefficient distribution in the region...

  12. Numerical prediction for effects of guide vane blade numbers on hydraulic turbine performance

    International Nuclear Information System (INIS)

    Shi, F X; Yang, J H; Wang, X H; Li, C E

    2013-01-01

    Using unstructured hybrid grid technique and SIMPLEC algorithm,a general three-dimensional simulation based on Reynolds Navier- stocks in multiple reference frames and the RNG k-ε turbulence model, is presented for the reversal centrifugal pump (PAT) with a guide vane. Four different schemes are designed by a change of the number of guide vane blade of PAT. The inner flow field in every scheme is simulated, accordingly, the external characteristic and static pressure distribution in flow field in PAT is obtained. The results obtained show that the efficiency can be improved by adding a guide vane for the PAT, besides, the high efficiency area is wider than before. Guide blade numbers changed, external characteristics of turbine changed, and the external characteristic changed. The optimal value is existent for the guide vane blade number, which has a great impact on the distribution of pressure in runner inlet

  13. Further development and performance evaluation of the autonomous sailing boat Maribot Vane

    OpenAIRE

    Dhomé, Ulysse

    2018-01-01

    This paper describes the ongoing development of Maribot Vane, an autonomous sailing vessel at the Maritime Robotics Laboratory of KTH, the Royal Institute of Technology, Stockholm. There is an ac-celerating need for ocean sensing where autonomous vehicles can play a key role in assisting scientists with environmental monitoring and collecting oceanographic data. The purpose of Maribot Vane is to offer a sus-tainable alternative for these autonomous missions by using wind and an energy efficie...

  14. Numerical modelling of multi-vane expander operating conditions in ORC system

    Science.gov (United States)

    Rak, Józef; Błasiak, Przemysław; Kolasiński, Piotr

    2017-11-01

    Multi-vane expanders are positive displacement volumetric machines which are nowadays considered for application in micro-power domestic ORC systems as promising alternative to micro turbines and other volumetric expanders. The multi-vane expander features very simple design, low gas flow capacity, low expansion ratios, an advantageous ratio of the power output to the external dimensions and are insensitive to the negative influence of the gas-liquid mixture expansion. Moreover, the multi-vane expander can be easily hermetically sealed, which is one of the key issues in the ORC system design. A literature review indicates that issues concerning the application of multi-vane expanders in such systems, especially related to operating of multi-vane expander with different low-boiling working fluids, are innovative, not fully scientifically described and have the potential for practical implementation. In this paper the results of numerical investigations on multi-vane expander operating conditions are presented. The analyses were performed on three-dimensional numerical model of the expander in ANSYS CFX software. The numerical model of the expander was validated using the data obtained from the experiment carried out on a lab test-stand. Then a series of computational analysis were performed using expanders' numerical model in order to determine its operating conditions under various flow conditions of different working fluids.

  15. Study on effects of mixing vane grids on coolant temperature distribution by subchannel analysis

    Energy Technology Data Exchange (ETDEWEB)

    Mao, H.; Yang, B.W.; Han, B. [Xi' an Jiaotong Univ., Shaanxi (China). Science and Technology Center for Advanced Nuclear Fuel Research

    2016-07-15

    Mixing vane grids (MVG) have great influence on coolant temperature field in the rod bundle. The MVG could enhance convective heat transfer between the fuel rod wall and the coolant, and promote inter-subchannel mixing at the same time. For the influence of the MVG on convective heat transfer enhancement, many experiments have been done and several correlations have been developed based on the experimental data. However, inter-subchannel mixing promotion caused by the MVG is not well estimated in subchannel analysis because the information of mixing vanes is totally missing in most subchannel codes. This paper analyzes the influence of mixing vanes on coolant temperature distribution using the improved MVG model in subchannel analysis. The coolant temperature distributions with the MVG are analyzed, and the results show that mixing vanes lead to a more uniform temperature distribution. The performances of split vane grids under different power conditions are evaluated. The results are compared with those of spacer grids without mixing vanes and some conclusions are obtained.

  16. Numerical modelling of multi-vane expander operating conditions in ORC system

    Directory of Open Access Journals (Sweden)

    Rak Józef

    2017-01-01

    Full Text Available Multi-vane expanders are positive displacement volumetric machines which are nowadays considered for application in micro-power domestic ORC systems as promising alternative to micro turbines and other volumetric expanders. The multi-vane expander features very simple design, low gas flow capacity, low expansion ratios, an advantageous ratio of the power output to the external dimensions and are insensitive to the negative influence of the gas-liquid mixture expansion. Moreover, the multi-vane expander can be easily hermetically sealed, which is one of the key issues in the ORC system design. A literature review indicates that issues concerning the application of multi-vane expanders in such systems, especially related to operating of multi-vane expander with different low-boiling working fluids, are innovative, not fully scientifically described and have the potential for practical implementation. In this paper the results of numerical investigations on multi-vane expander operating conditions are presented. The analyses were performed on three-dimensional numerical model of the expander in ANSYS CFX software. The numerical model of the expander was validated using the data obtained from the experiment carried out on a lab test-stand. Then a series of computational analysis were performed using expanders' numerical model in order to determine its operating conditions under various flow conditions of different working fluids.

  17. Numerical and experimental study of the leakage flow in guide vanes with different hydrofoils

    Directory of Open Access Journals (Sweden)

    Sailesh Chitrakar

    2017-07-01

    Full Text Available Clearance gaps between guide vanes and cover plates of Francis turbines tend to increase in size due to simultaneous effect of secondary flow and erosion in sediment affected hydropower plants. The pressure difference between the two sides of the guide vane induces leakage flow through the gap. This flow enters into the suction side with high acceleration, disturbing the primary flow and causing more erosion and losses in downstream turbine components. A cascade rig containing a single guide vane passage has been built to study the effect of the clearance gap using pressure sensors and PIV (Particle Image Velocimetry technique. This study focuses on developing a numerical model of the test rig, validating the results with experiments and investigating the behavior of leakage flow numerically. It was observed from both CFD and experiment that the leakage flow forms a passage vortex, which shifts away from the wall while travelling downstream. The streamlines contributing to the formation of this vortex have been discussed. Furthermore, the reference guide vane with symmetrical hydrofoil has been compared with four cambered profiles, in terms of the guide vane loading and the consequent effect on the leakage flow. A dimensionless term called Leakage Flow Factor (Lff has been introduced to compare the performances of hydrofoils. It is shown that the leakage flow and its effect on increasing losses and erosion can be minimized by changing the pressure distribution over the guide vane.

  18. Study on effects of mixing vane grids on coolant temperature distribution by subchannel analysis

    International Nuclear Information System (INIS)

    Mao, H.; Yang, B.W.; Han, B.

    2016-01-01

    Mixing vane grids (MVG) have great influence on coolant temperature field in the rod bundle. The MVG could enhance convective heat transfer between the fuel rod wall and the coolant, and promote inter-subchannel mixing at the same time. For the influence of the MVG on convective heat transfer enhancement, many experiments have been done and several correlations have been developed based on the experimental data. However, inter-subchannel mixing promotion caused by the MVG is not well estimated in subchannel analysis because the information of mixing vanes is totally missing in most subchannel codes. This paper analyzes the influence of mixing vanes on coolant temperature distribution using the improved MVG model in subchannel analysis. The coolant temperature distributions with the MVG are analyzed, and the results show that mixing vanes lead to a more uniform temperature distribution. The performances of split vane grids under different power conditions are evaluated. The results are compared with those of spacer grids without mixing vanes and some conclusions are obtained.

  19. Classic romance in electronic arrangement

    Directory of Open Access Journals (Sweden)

    Kizin M.M.

    2017-03-01

    Full Text Available this article analyses the transformation of the performing arts of classical romance in the terms of electronic sound and performance via electronic sounds arrangements. The author focuses on the problem of synthesis of electronic sound arrangements and classical romance, offering to acquire the skills of the creative process in constantly changing conditions of live performances.

  20. IAEA paper on institutional arrangements

    International Nuclear Information System (INIS)

    1979-01-01

    At its fifth series of meetings, Working Group 3 received a background paper prepared by the IAEA which had a threefold purpose: firstly, to provide an overview on institutional arrangements under consideration by the INFCE Working Groups; secondly, to explore potential relationships between the various institutional arrangements under consideration; and thirdly, to identify areas where further analysis might be desirable

  1. The experimental study on the wind turbine’s guide-vanes and diffuser of an exhaust air energy recovery system integrated with the cooling tower

    International Nuclear Information System (INIS)

    Chong, W.T.; Hew, W.P.; Yip, S.Y.; Fazlizan, A.; Poh, S.C.; Tan, C.J.; Ong, H.C.

    2014-01-01

    Highlights: • On-site exhaust air energy recovery turbine generator mounted above cooling tower. • Energy from wasted wind resources is re-used for electricity generation. • Optimum angle arrangement of guide-vanes and diffusers help to improve wind-flow. • Enclosure solves conventional wind turbine problems. • 13.3% reduction in CO 2 emission is expected to be achieved from this system. - Abstract: An assembly of two vertical axis wind turbines (VAWTs) and an enclosure is installed above a cooling tower to harness the discharged wind for electricity generation. The enclosure consists of guide-vanes and diffuser-plates, is used to enhance the rotational speed of the turbines for power augmentation. The angle of the guide-vanes is optimized to ensure the oncoming wind stream impinges the rotor blades of the turbine at an optimum angle. The diffuser-plates are tilted at an optimum angle to increase the discharged airflow rate. The performance of the system is tested in the laboratory followed by a field test on an actual size cooling tower. The VAWT performance is increased in the range of 7–8% with the integration of enclosure. There is no significant difference in the current consumption of the fan motor between the bare cooling tower and the one with installed VAWTs. With the presence of this system, approximately 17.5 GW h/year is expected to be recovered from 3000 units of cooling towers at commercial areas, assuming the cooling tower is driven by a 7.5 kW fan motor and operates 16 h/day. This amount of recovered energy can also be translated into 13% reduction in CO 2 emission

  2. Exergy Analysis of the Revolving Vane Compressed Air Engine

    Directory of Open Access Journals (Sweden)

    Alison Subiantoro

    2016-01-01

    Full Text Available Exergy analysis was applied to a revolving vane compressed air engine. The engine had a swept volume of 30 cm3. At the benchmark conditions, the suction pressure was 8 bar, the discharge pressure was 1 bar, and the operating speed was 3,000 rev·min−1. It was found that the engine had a second-law efficiency of 29.6% at the benchmark conditions. The contributors of exergy loss were friction (49%, throttling (38%, heat transfer (12%, and fluid mixing (1%. A parametric study was also conducted. The parameters to be examined were suction reservoir pressure (4 to 12 bar, operating speed (2,400 to 3,600 rev·min−1, and rotational cylinder inertia (0.94 to 2.81 g·mm2. The study found that a higher suction reservoir pressure initially increased the second-law efficiency but then plateaued at about 30%. With a higher operating speed and a higher cylinder inertia, second-law efficiency decreased. As compared to suction pressure and operating speed, cylinder inertia is the most practical and significant to be modified.

  3. On the study of wavy leading-edge vanes to achieve low fan interaction noise

    Science.gov (United States)

    Tong, Fan; Qiao, Weiyang; Xu, Kunbo; Wang, Liangfeng; Chen, Weijie; Wang, Xunnian

    2018-04-01

    The application of wavy leading-edge vanes to reduce a single-stage axial fan noise is numerically studied. The aerodynamic and acoustic performance of the fan is numerically investigated using a hybrid unsteady Reynolds averaged Navier-Stokes (URANS)/acoustic analogy method (Goldstein equations). First, the hybrid URANS/Goldstein method is developed and successfully validated against experiment results. Next, numerical simulations are performed to investigate the noise reduction effects of the wavy leading-edge vanes. The aerodynamic and acoustic performance is assessed for a fan with vanes equipped with two different wavy leading-edge profiles and compared with the performance of conventional straight leading-edge vanes. Results indicate that a fan with wavy leading-edge vanes produces lower interaction noise than the baseline fan without a significant loss in aerodynamic performance. In fact, it is demonstrated that wavy leading-edge vanes have the potential to lead to both aerodynamic and acoustic improvements. The two different wavy leading-edge profiles are shown to successfully reduce the fan tone sound power level by 1.2 dB and 4.3 dB, respectively. Fan efficiency is also improved by about 1% with one of the tested wavy leading-edge profiles. Large eddy simulation (LES) is also performed for a simplified fan stage model to assess the effects of wavy leading-edge vanes on the broadband fan noise. Results indicate that the overall sound power level of a fan can be reduced by about 4 dB with the larger wavy leading-edge profile. Finally, the noise reduction mechanisms are investigated and analysed. It is found that the wavy leading-edge profiles can induce significant streamwise vorticity around the leading-edge protuberances and reduce pressure fluctuations (especially at locations of wavy leading-edge hills) and unsteady forces on the stator vanes. The underlying mechanism of the reduced pressure fluctuations is also discussed by examining the magnitude

  4. Test procedure for use of the shear vane in tanks 103-SY, 103-AN, and 103-AW

    International Nuclear Information System (INIS)

    LeClair, M.D.; Waters, E.

    1995-01-01

    This is a record copy of a test procedure for application of the full-scale shear vane to underground waste tanks at Hanford. The introduction of the report provides background information on the development and proof-testing of the shear vane, as well as information about its current location. The document was originally prepared in 1988, and the work as shelved temporarily for lack of funds. Activities to utilize the shear vane will be expedited by use of this information

  5. Tandem mirror reactor

    International Nuclear Information System (INIS)

    Moir, R.W.; Barr, W.L.; Carlson, G.A.

    1977-01-01

    A parametric analysis and a preliminary conceptual design for a 1000 MWe Tandem Mirror Reactor (TMR) are described. The concept is sufficiently attractive to encourage further work, both for a pure fusion TMR and a low technology TMR Fusion-Fission Hybrid

  6. Evaluation of effect of low opening operation on increasing wear of bearing bushings of guide vanes used in hydropower plants

    International Nuclear Information System (INIS)

    Kim, Jong Sung; Kim, Se Na

    2012-01-01

    A guide vane plays a key role in controlling the flow rate of water supplied to the turbine of a hydropower plant. It has been reported that guide vane bearing bushings are subjected to considerable wear, which requires them to be maintained. An ancillary service such as frequency control and black start causes cyclic low opening operation of the guide vanes. It is empirically well known that such operation increases the wear rate of the guide vane bearing bushing. In this study, the effect of low opening operation on the increasing wear of the guide vane bearing bushing is quantitatively assessed via finite element flow analysis, finite element stress analysis, and relative wear evaluation. As a result of the assessment, it is identified that the pressure applied on the guide vane surface increases and the contact length between the outer surface of the guide vane stem and the inner surface of the bearing bushing decreases with a decrease in the opening of the guide vane. In addition, low opening of the guide vanes results in an increase in the relative wear owing to the generation of high contact pressure on the bearing bushing surfaces

  7. Determinants of flexible work arrangements

    OpenAIRE

    Sarbu, Miruna

    2014-01-01

    Flexible work arrangements such as allowing employees to work at home are used in firms, especially since information and communication technologies have become so widespread. Using individual-level data from 10,884 German employees, this paper analyses the determinants of working at home as a form of flexible work arrangements. The analysis is based on descriptive analyses and a discrete choice model using a probit estimation approach. The results reveal that men have a higher...

  8. The Politics of Legal Arrangements

    DEFF Research Database (Denmark)

    Leander, Anna

    2018-01-01

    This article explores the place of formal legal arrangements in the politics surrounding the hybrid, enmeshed public-in-the-private forms of authority this special issue focuses on. It does so by analyzing the significance of one specific legal arrangement, the Duty of Care, for the politics...... and divisions currently organizing debates about the regulation of commercial security as well as about managerialism in international law more generally....

  9. Performance improvement of a centrifugal compressor stage by using different vaned diffusers

    International Nuclear Information System (INIS)

    Zhang, Y C; Kong, X Z; Li, F; Sun, W; Chen, Q G

    2013-01-01

    The vaneless diffuser (VLD) is usually adopted in the traditional design of the multi-stage centrifugal compressor because of the stage's match problem. The drawback of the stage with vaneless diffusers is low efficiency. In order to increase the efficiency and at the same time, induce no significant decline in the operating range of the stage, three different types of vaned diffusers are designed and numerically investigated: the traditional vaned diffuser (TVD), the low-solidity cascade diffuser (LSD) and the partial-height vane diffuser (PVD). These three types of vaned diffusers have different influences on the performance of the centrifugal compressor. In the present investigation, the first part investigates the performance of a centrifugal compressor stage with three different vaned diffusers. The second part studies the influences of the height and the position of partial height vanes on the stage performance, and discusses the matching problem between the PVD and the downstream return channel. The stage investigated in this paper includes the impeller, the diffuser, the bend and the return channel. In the process of numerical investigation, the flow is assumed to be steady, and this process includes calculation and simulation. The calculation of 3-D turbulent flow in the stage uses the commercial CFD code NUMECA together with the Spalart-Allmaras turbulence model. The simulation of the computational region includes the impeller passages, the diffuser passages and return channel passages. The structure and surrounding region are assumed to have a perfect cyclic symmetry, so the single channel model and periodic boundary condition are applied at the middle of the passage, that is to reduce the calculation region to only one region. The investigation showed that the low-solidity cascade diffuser would be a better choice as a middle course for the first stage of the multistage centrifugal compressor. Besides, the influences of the height and the position

  10. Design and numerical investigation of swirl recovery vanes for the Fokker 29 propeller

    Directory of Open Access Journals (Sweden)

    Wang Yangang

    2014-10-01

    Full Text Available Swirl recovery vanes (SRVs are a set of stationary vanes located downstream from a propeller, which may recover some of the residual swirl from the propeller, hoping for an improvement in both thrust and efficiency. The SRV concept design for a scaled version representing the Fokker 29 propeller is performed in this paper, which may give rise to a promotion in propulsive performance of this traditional propeller. Firstly the numerical strategy is validated from two aspects of global quantities and the local flow field of the propeller compared with experimental data, and then the exit flow together with the development of propeller wake is analyzed in detail. Three kinds of SRV are designed with multiple circular airfoils. The numerical results show that the swirl behind the propeller is recovered significantly with Model V3, which is characterized by the highest solidity along spanwise, for various working conditions, and the combination of rotor and vane produced 5.76% extra thrust at the design point. However, a lower efficiency is observed asking for a better vane design and the choice of a working point. The vane position is studied which shows that there is an optimum range for higher thrust and efficiency.

  11. Velocity and pressure measurements in guide vane clearance gap of a low specific speed Francis turbine

    Science.gov (United States)

    Thapa, B. S.; Dahlhaug, O. G.; Thapa, B.

    2016-11-01

    In Francis turbine, a small clearance gap between the guide vanes and the cover plates is usually required to pivot guide vanes as a part of governing system. Deflection of cover plates and erosion of mating surfaces causes this gap to increase from its design value. The clearance gap induces the secondary flow in the distributor system. This effects the main flow at the runner inlet, which causes losses in efficiency and instability. A guide vane cascade of a low specific speed Francis turbine has been developed for experimental investigations. The test setup is able to produce similar velocity distributions at the runner inlet as that of a reference prototype turbine. The setup is designed for particle image velocimetry (PIV) measurements from the position of stay vane outlet to the position of runner inlet. In this study, velocity and pressure measurements are conducted with 2 mm clearance gap on one side of guide vane. Leakage flow is observed and measured together with pressure measurements. It is concluded that the leakage flow behaves as a jet and mixes with the main flow in cross-wise direction and forms a vortex filament. This causes non-uniform inlet flow conditions at runner blades.

  12. The tandem betatron accelerator

    International Nuclear Information System (INIS)

    Keinigs, R.

    1991-01-01

    This paper reports that the tandem betatron is a compact, high-current induction accelerator that has the capability to accelerate electrons to an energy of order one gigavolt. Based upon the operating principle of a conventional betatron, the tandem betatron employs two synchronized induction cores operating 180 degrees out of phase. Embedded within the cores are the vacuum chambers, and these are connected by linear transport sections to allow for moving the beam back and forth between the two betatrons. The 180 degree phase shift between the core fluxes permits the circumvention of the flux swing constraint that limits the maximum energy gain of a conventional betatron. By transporting the beam between the synchronized cores, an electron can access more than one acceleration cycle, and thereby continue to gain energy. This added degree of freedom also permits a significant decrease in the size of the magnet system. Biasing coils provide independent control of the confining magnetic field. Provided that efficient beam switching can be performed, it appears feasible that a one gigavolt electron beam can be generated and confined. At this energy, a high current electron beam circulating in a one meter radius orbit could provide a very intense source of short wavelength (λ < 10 nm) synchrotron radiation. This has direct application to the emerging field of x-ray lithography. At more modest energies (10 MeV-30 MEV) a compact tandem betatron could be employed in the fields of medical radiation therapy, industrial radiography, and materials processing

  13. Discussion on the re-irradiated fuel assembly with damaged guide vanes

    International Nuclear Information System (INIS)

    Li Ligang

    2013-01-01

    In January 2011, during the second plant of CNNC Nuclear Power Operations Management Co., Ltd.(hereinafter referred to as the second plant) refueling outage, the visual inspection found the guide vanes of fuel assembly A had felling off. After the National Nuclear Safety Administration (NNSA) estimated and approved, the fuel assembly A was reloaded in the specified location of reactor core. During the refueling outage in March 2012, the fuel assembly A was removed again from the reactor core. Visual inspection confirmed that the fuel assembly A was complete and without abnormal changes. The practice provides reference for re-irradiated of fuel assembly with the same type of damaged guide vanes, and provides case support for standard development for the same type of re-irradiated fuel assembly with damaged guide vanes. (author)

  14. Enlarging the operation range of a centrifugal compressor by cutting vanes based on CFD

    International Nuclear Information System (INIS)

    Mo, J T; Pan, X H; Gu, C H; Zheng, S Y

    2013-01-01

    Many centrifugal compressors are liable to insufficient operation range. The purpose of this paper is to enlarge the operation range of a centrifugal compressor used in turbocharger by cutting vanes. Some numerical works have been done based on CFD. The comparison of the calculated and measured results shows good agreement. The overall performance characteristics of the centrifugal compressor with different cutted vanes are observed and analyzed. The performance characteristic curves show that cutting vanes can increase the operation range by more than 50% with the loss of the highest efficiency limited in 1%. The flow fields are also shown in this paper and related explanations about the change of the performance characteristics curves are given. Shock wave is also detected in the simulation, and some related characteristics are summed up

  15. Performance Analysis of a Centrifugal Compressor for HFC-134a with aviation of Diffuser Vane Angle

    International Nuclear Information System (INIS)

    Park, Han Young; Chung, Jin Taek; Shin, You Hwan; Lee, Yoon Pyo; Kim, Kwang Ho; Cho, Yong Hun; Kim, Jong Seong

    2007-01-01

    Numerical simulation on the two-stage centrifugal compressor with Low Solidity Vaned Diffuser (LSVD) for HFC-134a turbo-chiller was performed using a commercial code. The comparative study with experimental results from other compressor was also investigated to testify the simulation schemes. The numerical analysis was separately simulated for each stage of the compressor and the effect of impeller-diffuser flow interaction was considered. Setting angle of the diffuser vane changed in the range of 15 .deg. and the effects on its variation were discussed in detail including the flow analysis in the passage of the compressor. The vane setting angle obtained from the preliminary design was slightly adjusted to the optimal value by the performance enhancement in terms of pressure recovery and flow characteristics

  16. Effect of spacer grid mixing vanes on coolant outlet temperature distribution

    Energy Technology Data Exchange (ETDEWEB)

    Raemae, Tommi; Lahtinen, Tuukka; Brandt, Tellervo; Toppila, Timo [Fortum Power and Heat, Fortum (Finland). Nuclear Competence Center

    2012-08-15

    In Loviisa VVER-440-type NPP the coolant outlet temperature of the hot subchannel is constantly monitored during the operation. According to the authority requirement the maximum subchannel outlet temperature must not exceed the saturation temperature. Coolant temperature distribution inside the fuel assembly is affected by the efficiency of the coolant mixing. In order to enhance the coolant mixing the fuel manufacturer is introducing the additional mixing vanes on the fuel bundle spacer grids. In the paper the effect of the different mixing vane modifications is studied with computational fluid dynamics (CFD) simulation. Goal of the modelling is to find vane modifications with which sufficient mixing is reached with acceptable increase in the spacer grid pressure loss. The results of the studies are discussed in the paper. (orig.)

  17. Performance and internal flow characteristics of a cross-flow turbine by guide vane angle

    International Nuclear Information System (INIS)

    Chen, Z M; Choi, Y D

    2013-01-01

    This study attempts to investigate the performance and internal flow characteristics of a cross-flow turbine by guide vane angle. In order to improve the performance of a cross flow turbine, the paper presents a numerical investigation of the turbine with air supply and discusses the influence of variable guide vane angle on the internal flow. A newly developed air supply from air suction Hole is adopted. To investigate the performance and internal flow of the cross-flow turbine, the CFD software based on the two-phase flow model is utilized. The numerical grids are made in two-dimensional geometry in order to shorten the time of two-phase calculations. Then a series of CFD analysis has been conducted in the range of different guide vane angle. Moreover, local output power is divided at different stages and the effect of air layer in each stage is examined

  18. Assessment of guide vane self-excitation stability at small openings in pump flow

    International Nuclear Information System (INIS)

    Nennemann, B; Sallaberger, M; Henggeler, U; Gentner, C; Parkinson, E

    2012-01-01

    A parameter study of self-excited pump turbine guide vane instability at small openings using a combined CFD-1DOF approach shows that clear tendencies are difficult to obtain. Two types of boundary conditions can be used in the simulations: prescribed mass flow and prescribed pressure. Simulations with both show results that - for one specific operating condition - are consistent with a self-excited guide vane incident at a prototype pump turbine. However, over a larger range of reduced velocities, the tendencies obtained with the two boundary condition types are not always consistent. Pressure boundary conditions may be the more realistic option. Results then show that with increasing reduced velocity, guide vanes will eventually reach static instability or divergence. This may not be problematic. In contrast, passing through a zone of dynamic instability during operation should and can be avoided.

  19. On the Relativistic Correction of Particles Trajectory in Tandem Type Electrostatic Accelerator

    Directory of Open Access Journals (Sweden)

    Minárik Stanislav

    2015-08-01

    Full Text Available A constant potential is applied to the acceleration of the ion-beam in the tandem type electrostatic accelerator. However, not just one voltage is applied, but instead a number of applications can be made in succession by means of the tandem arrangement of high voltage tubes. This number of voltage applications, which is the number of so-called "stages" of a tandem accelerator, may be two, three, or four, depending on the chosen design. Electrostatic field with approximately constant intensity acts on ions in any stage.

  20. Arranged marriages annulled by law.

    Science.gov (United States)

    Zhu, H

    1996-06-01

    The arranged marriages of 210 young people in Yongle Town in Zunyi County of Guizhou Province were dissolved in 1995. The proportion of child betrothals, which generally happens among close relatives, is as high as 85% in the town. Some engagements, known as fetus betrothals or belt betrothals, are arranged before the children are born or while they are still infants strapped (belted) to their mothers. Dissemination of information from the Constitution, the Marriage Law, and the Regulations on the Registration of Marriage concerning marriage, healthier births, and good upbringing of children, and other information on reproductive health, has shown young people that they have the freedom to love and marry of their own free will, that their marriage is protected by law, and that consanguineous marriage is harmful to the health of future generations. Some convinced their parents that their arranged marriages should be annulled.

  1. Sealing arrangement for radioactive material

    International Nuclear Information System (INIS)

    Gray, I.L.S.; Sievwright, R.W.T.; Elliott, J.C.

    1993-01-01

    A sealing arrangement for hermetically sealing two mating surfaces comprises two seals arranged to lie between the surfaces. Each seal provides hermetic sealing over a respective different temperature range and lie serially along the surfaces between the regions to be isolated. A main seal integrity test arrangement is provided in the form of a port and passage. This allows for the introduction of a fluid into or the evacuation of a region between the two seals to detect a leak. The port is also provided with at least two test port seals which seal with a plug. The plug is also provided with a test port to allow the integrity of the test port seal to be tested. (UK)

  2. Storage arrangements for nuclear fuel

    International Nuclear Information System (INIS)

    Deacon, D.

    1982-01-01

    A storage arrangement for spent nuclear fuel either irradiated or pre-irradiated or for vitrified waste after spent fuel reprocessing, comprises a plenum chamber which has a base pierced by a plurality of openings each of which has sealed to it an open topped tube extending downwards and closed at its lower end. The plenum chamber, with the tubes, forms an air-filled enclosure associated with an exhaust system for exhausting air from the system through filters to maintain the interior of the enclosure at sub-atmospheric pressure. The tubes are arranged to accommodate the stored fuel and the arrangement includes a means for producing a flow of cooling air over the exterior of the tubes so that the latter effectively form a plurality of heat exchangers in close proximity to the fuel. The air may be caused to flow over the tube surfaces by a natural thermosyphon process. (author)

  3. Study of turbine and guide vanes integration to enhance the performance of cross flow vertical axis wind turbine

    Science.gov (United States)

    Wibowo, Andreas; Tjahjana, Dominicus Danardono Dwi Prija; Santoso, Budi; Situmorang, Marcelinus Risky Clinton

    2018-02-01

    The main purpose of this study is to investigate the best configuration between guide vanes and cross flow vertical axis wind turbine with variation of several parameters including guide vanes tilt angle and the number of turbine and guide vane blades. The experimental test were conducted under various wind speed and directions for testing cross flow wind turbine, consisted of 8, 12 and 16 blades. Two types of guide vane were developed in this study, employing 20° and 60° tilt angle. Both of the two types of guide vane had three variations of blade numbers which had same blade numbers variations as the turbines. The result showed that the configurations between 60° guide vane with 16 blade numbers and turbine with 16 blade numbers had the best configurations. The result also showed that for certain configuration, guide vane was able to increase the power generated by the turbine significantly by 271.39% compared to the baseline configuration without using of guide vane.

  4. Design and experimental validation of the inlet guide vane system of a mini hydraulic bulb-turbine

    Energy Technology Data Exchange (ETDEWEB)

    Ferro, L.M.C. [Department of Mechanical Engineering, Escola Superior de Tecnologia de Setubal, Polytechnic Institute of Setubal, Campus do IPS, Estefanilha, 2910-761 Setubal (Portugal); IDMEC, Instituto Superior Tecnico, Technical University of Lisbon, Av. Rovisco Pais,1049-001 Lisboa (Portugal); Gato, L.M.C.; Falcao, A.F.O. [IDMEC, Instituto Superior Tecnico, Technical University of Lisbon, Av. Rovisco Pais,1049-001 Lisboa (Portugal)

    2010-09-15

    The paper presents a fast design method for the inlet guide vanes of low-cost mini hydraulic bulb turbines. The guide vanes are positioned between two conical surfaces with a common vertex and have constant thickness distribution, except close to the leading and the trailing edges. The conical-walled inlet guide vane row is designed using a quasi-three-dimensional calculation method, by prescribing the angular-momentum distribution along the span at the outlet section of the guide vanes. The meridional through-flow is computed by a streamline curvature method and the blade-to-blade flow by a singularity surface method. The stagger angle and the vane camber are computed to fulfil the required design circulation and zero-incidence flow at the leading edge. The final vane shape is a single-curvature surface with straight leading and trailing edges. To validate the design method, a conical-walled inlet guide vane row nozzle-model with six fixed vanes was designed, manufactured and tested in an airflow rig. Traversing measurements along the circumferential and radial directions were made with a five-hole probe. The experimental results are compared with the prescribed design conditions and with numerical results from the three-dimensional inviscid and viscous flow computed with the FLUENT code. (author)

  5. Patient positioning and supporting arrangement

    International Nuclear Information System (INIS)

    Heavens, M.; James, R.C.; Slinn, D.S.

    1980-01-01

    This patent specification describes an E.M.I. claim relating to a patient positioning and support arrangement for a computerised axial tomography system, the arrangement comprising a curved platter upon which the patient can be disposed, a table having a curved groove to accommodate the platter, and means for driving the platter slidably along the groove; the platter being formed of a substantially rigid platform shaped to conform to the groove, and a shroud, secured to the platter and disposed between the platter and the surface of the groove, so as to permit the platter to slide smoothly. (U.K.)

  6. CFD analysis of supercritical water flow and heat transfer in single channel with mixing vane

    International Nuclear Information System (INIS)

    Zuo Guoping; Xie Hongyan; Yu Tao

    2012-01-01

    Three-dimensional rectangular channel with the mixing wane in supercritical water reactor is investigated with CFX. The mixing vane elevation influenced on temperature distribution and flow field are simulated in the model. The results showed the mixing vane cause fluid circumferential flow, making flow hot and cold fluids mixed and fluid temperature uniform distribution, effectively improve the fuel rod surface temperature distribution and reduced hot temperature. Among the mixing wing elevation of 15, 30, 45, 50, 60 and 70 angle, the 30 angle is the best case in improving temperature distribution. (authors)

  7. Reduction of background noise induced by wind tunnel jet exit vanes

    Science.gov (United States)

    Martin, R. M.; Brooks, T. F.; Hoad, D. R.

    1985-01-01

    The NASA-Langley 4 x 7 m wind tunnel develops low frequency flow pulsations at certain velocity ranges during open throat mode operation, affecting the aerodynamics of the flow and degrading the resulting model test data. Triangular vanes attached to the trailing edge of flat steel rails, mounted 10 cm from the inside of the jet exit walls, have been used to reduce this effect; attention is presently given to methods used to reduce the inherent noise generation of the vanes while retaining their pulsation reduction features.

  8. Analytical solution for the electrical properties of a radio-frequency quadrupole (RFQ) with simple vanes

    International Nuclear Information System (INIS)

    Lancaster, H.

    1982-01-01

    Although the SUPERFISH program is used for calculating the design parameters of an RFQ structure with complex vanes, an analytical solution for electrical properties of an RFQ with simple vanes provides insight into the parametric behavior of these more complicated resonators. The fields in an inclined plane wave guide with proper boundary conditions match those in one quadrant of an RFQ. The principle of duality is used to exploit the solutions to a radial transmission line in solving the field equations. Calculated are the frequency equation, frequency sensitivity factors, electric field, magnetic field, stored energy (U), power dissipation, and quality factor

  9. Effects of the friction coefficient on the torque characteristics of a hydraulic cam-rotor vane motor

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Qiankun; Wang, Xuyong; Yuan, Fan; Chen, Liang Shen; Tao, Jian Feng [School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai (China); Miao, Zhong Hua [School of Mechatronic Engineering and Automation, Shanghai University, Shanghai (China)

    2016-08-15

    The friction coefficient between the vane and the slot is one of the most critical factors that affects the performance of a continuous rotary hydraulic cam-rotor vane motor. To study the effects of this coefficient on the torque characteristics of the motor, the mathematical model for the normal force and the disturbing torque between the cam rotors and the vanes of the motor was established by analyzing the forces exerted on the vanes. The mathematical model was simulated with MATLAB, and simulation results show that an increase in the friction coefficient would simultaneously decrease the normal force and increase the disturbing torque, which would negatively affect the performance of the motor. Further experimental research indicated that the low-speed performance of the hydraulic cam-rotor motor was significantly improved when the friction coefficient was reduced by controlling the parallelism tolerance, flatness and roughness between the vanes and the slots.

  10. Tandem accelerator operation and improvements

    International Nuclear Information System (INIS)

    Yang Bingfan; Zhang Canzhe; Qin Jiuchang; Hu Yueming; Zhang Guilian; Jiang Yongliang; Hou Deyi; Yang Weimin; Yang Zhiren; Su Shengyong; Kan Chaoxin; Liu Dezhong; Wang Liyong; Bao Yiwen; You Qubo; Yang Tao; Zhang Yan; Zhou Lipeng; Chai Shiqin; Wang Meiyan

    1998-01-01

    The scheduled operation of HI-13 tandem accelerator for various experiments was performed well in 1996 and 1997. The machine running time was 4600 h and 4182 h while the beam time was 3845 h and 3712 h in 1996 and 1997, respectively. The operation of HI-13 tandem accelerator is pretty well. The beam distribution with terminal voltage and the distribution of beam time with ion species are shown out. The development of accelerating tubes for HI-13 tandem is in progress

  11. Combustion-driven oscillation in a furnace with multispud-type gas burners. 4th Report. Effects of position of secondary air guide sleeve and openness of secondary air guide vane on combustion oscillation condition; Multispud gata gas turner ni okeru nensho shindo. 4. Nijigen kuki sleeve ichi oyobi nijigen kuki vane kaido no shindo reiki ni oyobosu eikyo

    Energy Technology Data Exchange (ETDEWEB)

    Akiyama, I.; Okiura, K.; Baba, A.; Orimoto, M. [Babcock-Hitachi K.K., Tokyo (Japan)

    1994-07-25

    Effects of the position of a secondary air guide sleeve and the openness of a secondary air guide vane on combustion oscillation conditions were studied experimentally for multispud-type gas burners. Pressure fluctuation in furnaces was analyzed with the previously reported resonance factor which was proposed as an index to represent the degree of combustion oscillation. As a result, the combustion oscillation region was largely affected by both position of a guide sleeve and openness of a guide vane. As the openness having large effect on the ratio of primary and secondary air/tertiary air and the position hardly having effect on the ratio were adjusted skillfully, the burner with no combustion oscillation region was achieved in its normal operation range. In addition, as the effect of preheating combustion air was arranged with a standard flow rate or mass flow flux of air, it was suggested the combustion oscillation region due to preheating can be described with the same manner as that due to no preheating. 5 refs., 8 figs.

  12. Static thrust-vectoring performance of nonaxisymmetric convergent-divergent nozzles with post-exit yaw vanes. M.S. Thesis - George Washington Univ., Aug. 1988

    Science.gov (United States)

    Foley, Robert J.; Pendergraft, Odis C., Jr.

    1991-01-01

    A static (wind-off) test was conducted in the Static Test Facility of the 16-ft transonic tunnel to determine the performance and turning effectiveness of post-exit yaw vanes installed on two-dimensional convergent-divergent nozzles. One nozzle design that was previously tested was used as a baseline, simulating dry power and afterburning power nozzles at both 0 and 20 degree pitch vectoring conditions. Vanes were installed on these four nozzle configurations to study the effects of vane deflection angle, longitudinal and lateral location, size, and camber. All vanes were hinged at the nozzle sidewall exit, and in addition, some were also hinged at the vane quarter chord (double-hinged). The vane concepts tested generally produced yaw thrust vectoring angles much less than the geometric vane angles, for (up to 8 percent) resultant thrust losses. When the nozzles were pitch vectored, yawing effectiveness decreased as the vanes were moved downstream. Thrust penalties and yawing effectiveness both decreased rapidly as the vanes were moved outboard (laterally). Vane length and height changes increased yawing effectiveness and thrust ratio losses, while using vane camber, and double-hinged vanes increased resultant yaw angles by 50 to 100 percent.

  13. Nuclear reactor core stabilizing arrangement

    International Nuclear Information System (INIS)

    Jabsen, F.S.

    1976-01-01

    A nuclear reactor core stabilizing arrangement is described wherein a plurality of actuators, disposed in a pattern laterally surrounding a group of elongated fuel assemblies, press against respective contiguous fuel assemblies on the periphery of the group to reduce the clearance between adjacent fuel assemblies thereby forming a more compacted, vibration resistant core structure. 7 claims, 4 drawing figures

  14. Teaching Determinants Using Rook Arrangements

    Science.gov (United States)

    Hendrickson, Anders O. F.

    2018-01-01

    Teaching determinants poses significant challenges to the instructor of a proof-based undergraduate linear algebra course. The standard definition by cofactor expansion is ugly, lacks symmetry, and is hard for students to use in proofs. We introduce a visual definition of the determinant that interprets permutations as arrangements of…

  15. Special Issue: Flexible Work Arrangements.

    Science.gov (United States)

    Olmstead, Barney, Ed.

    1996-01-01

    Section 1 contains five chapters on flexible work arrangements, self-employment, working from home, part-time professionals, job sharing, and temporary employment. Section 2 includes reviews of four books on working flexibly, concluding with a list of 23 additional readings. (SK)

  16. Arrangement for guiding transport cables

    International Nuclear Information System (INIS)

    1981-01-01

    This patent relates especially to x-ray equipment such as that used for computerized tomography, and in particular to an arrangement for guiding and supporting a plurality of power transmission cables and cooling hoses in a flexible manner. (U.K.)

  17. Storage arrangements for nuclear fuel

    International Nuclear Information System (INIS)

    Ealing, C.J.

    1985-01-01

    A storage arrangement for nuclear fuel has a plurality of storage tubes connected by individual pipes to manifolds which are connected, in turn, to an exhaust system for maintaining the tubes at sub-atmospheric pressure, and means for producing a flow of a cooling fluid, such as air, over the exterior surfaces of the tubes. (author)

  18. Flow control arrangements for centrifuges

    International Nuclear Information System (INIS)

    Alderton, G.W.; Davidge, P.C.

    1983-01-01

    In a centrifuge plant for the separation of uranium isotopes, when a centrifuge machine breaks down, light gas is produced. This gas can cause adjacent machines to break down, so propagating the fault. The present invention provides flow control arrangements in gas pipes to the centrifuge, whereby sudden egress of gas from a failed machine is inhibited. (author)

  19. ''VaneCAM'' - the third generation of camshaft adjustment systems; ''VaneCAM'' - Nockenwellenversteller der dritten Generation

    Energy Technology Data Exchange (ETDEWEB)

    Knecht, A. [Hydraulik-Ring GmbH, Nuertingen (Germany). Entwicklung Motorentechnik; Stephan, W. [Hydraulik-Ring GmbH, Nuertingen (Germany); Hannibal, W. [Fachhochschule Suedwestfalen, Iserlohn (Germany). Labor fuer Konstruktion und CAE-Anwendungen

    2002-04-01

    Continuously variable camphasers are now well established for modern spark-ignition engines in high-volume production. With the latest generation of camshaft adjustment systems using the vane-type actuator principle, it is possible to move rapidly and reliably through a large adjustment angle. The layout of these adjusting systems is very simple. The production costs are low in comparison to the first generation of camphasers using spur/helical gears to vary the valve timing. The new-generation systems are mechatronic, with the function depending on the coordination and tuning of hydraulic actuation and engine electronics. The term 'VaneCAM' is used for the continuously variable systems of this new generation supplied by Hydraulik-Ring in Nuertingen, Germany. (orig.) [German] Stufenlos wirkende Nockenwellenversteller haben sich an modernen Ottomotoren in den letzten Jahren in der Grossserie etabliert. Mit der neuesten Generation von Nockenwellenverstellern, die nach dem Schwenkmotor-Prinzip aufgebaut sind, lassen sich grosse Verdrehwinkel sehr schnell und betriebssicher verstellen. Der Aufbau dieser Versteller ist einfach, und die Herstellkosten sind gering im Vergleich zur ersten Generation von Verstellern. Bei den Systemen der neuen Generation handelt es sich um mechatronische Systeme, deren Funktion von dem Zusammenspiel und der Abstimmung von hydraulischer Ansteuerung und Motorelektronik abhaengt. Mit dem Begriff 'VaneCAM' werden die stufenlos wirkenden Systeme dieser neuen Generation von Hydraulik-Ring aus Nuertingen bezeichnet. (orig.)

  20. Experimental Investigation of Turbine Vane Heat Transfer for Alternative Fuels

    Energy Technology Data Exchange (ETDEWEB)

    Nix, Andrew Carl [West Virginia Univ., Morgantown, WV (United States)

    2015-03-23

    The focus of this program was to experimentally investigate advanced gas turbine cooling schemes and the effects of and factors that contribute to surface deposition from particulate matter found in coal syngas exhaust flows on turbine airfoil heat transfer and film cooling, as well as to characterize surface roughness and determine the effects of surface deposition on turbine components. The program was a comprehensive, multi-disciplinary collaborative effort between aero-thermal and materials faculty researchers and the Department of Energy, National Energy Technology Laboratory (NETL). The primary technical objectives of the program were to evaluate the effects of combustion of syngas fuels on heat transfer to turbine vanes and blades in land-based power generation gas turbine engines. The primary questions to be answered by this investigation were; What are the factors that contribute to particulate deposition on film cooled gas turbine components? An experimental program was performed in a high-temperature and pressure combustion rig at the DOE NETL; What is the effect of coal syngas combustion and surface deposition on turbine airfoil film cooling? Deposition of particulate matter from the combustion gases can block film cooling holes, decreasing the flow of the film coolant and the film cooling effectiveness; How does surface deposition from coal syngas combustion affect turbine surface roughness? Increased surface roughness can increase aerodynamic losses and result in decreased turbine hot section efficiency, increasing engine fuel consumption to maintain desired power output. Convective heat transfer is also greatly affected by the surface roughness of the airfoil surface; Is there any significant effect of surface deposition or erosion on integrity of turbine airfoil thermal barrier coatings (TBC) and do surface deposits react with the TBC in any way to decrease its thermal insulating capability? Spallation and erosion of TBC is a persistent problem in

  1. Erosion estimation of guide vane end clearance in hydraulic turbines with sediment water flow

    Science.gov (United States)

    Han, Wei; Kang, Jingbo; Wang, Jie; Peng, Guoyi; Li, Lianyuan; Su, Min

    2018-04-01

    The end surface of guide vane or head cover is one of the most serious parts of sediment erosion for high-head hydraulic turbines. In order to investigate the relationship between erosion depth of wall surface and the characteristic parameter of erosion, an estimative method including a simplified flow model and a modificatory erosion calculative function is proposed in this paper. The flow between the end surfaces of guide vane and head cover is simplified as a clearance flow around a circular cylinder with a backward facing step. Erosion characteristic parameter of csws3 is calculated with the mixture model for multiphase flow and the renormalization group (RNG) k-𝜀 turbulence model under the actual working conditions, based on which, erosion depths of guide vane and head cover end surfaces are estimated with a modification of erosion coefficient K. The estimation results agree well with the actual situation. It is shown that the estimative method is reasonable for erosion prediction of guide vane and can provide a significant reference to determine the optimal maintenance cycle for hydraulic turbine in the future.

  2. Static pressure recovery analysis in the vane island diffuser of a centrifugal pump

    Energy Technology Data Exchange (ETDEWEB)

    Si, Qiaorui [National Research Center of Pumps, Jiangsu University, Zhenjiang (China); Dupont, Patrick; Bayeul-Laine, Annie-Claude; Dazin, Antoine; Roussette, Olivier; Bois, Gerard [LML, UMR CNRS 8107 Ecole Centrale de Lille, Lille (France)

    2016-02-15

    The overall performance of a vane-island type diffuser of a centrifugal pump model was obtained by means of directional probe traverses. These measurements were performed in an air model of a real hydraulic pump for five volume flow rates. Directional probe traverses are performed with a classical three-hole probe to cover most of the complete inlet section of the diffuser from hub to shroud and from pressure to suction side. Existing Particle image velocimetry (PIV) measurement results are also used to compare probe measurement results between the inlet and outlet throats of vane island diffuser at mid-span. Some assistance from already existing unsteady calculation, including leakage effects, is used to evaluate the numerical approach capability and to correctly define the mean initial conditions at impeller's outlet section. Pressure recovery and the measured total pressure loss levels inside this particular vane diffuser geometry are then calculated. Detailed analysis of the flow structure at the inlet section of the vane island diffuser is presented to focus on pressure evolution inside the entire diffuser section for different flow rates. The combined effects of incidence angle and blockage distributions along hub to shroud direction are found to play an important role on loss distribution in such a diffuser.

  3. the screw-conveyor vane design for piece-wise construction

    African Journals Online (AJOL)

    Dr Obe

    Summary. One of the long-used methods of conveying granular, Powdery or slurry material is by the screw conveyor. This method of transport is well suited to some at the needs of local processing Industries based on such local produce as millet, maize, cocoa-beans, rice, palm-kernels. The spiral vanes of such conveyors ...

  4. Performance of an alpha-vane and pitot tube in simulated heavy rain environment

    Science.gov (United States)

    Luers, J. K.; Fiscus, I. B.

    1985-01-01

    Experimental tests were conducted in the UDRI Environmental Wind/Rain Tunnel to establish the performance of an alpha-vane, that measures angle of attack, in a simulated heavy rain environment. The tests consisted of emersing the alpha-vane in an airstream with a concurrent water spray penetrating vertically through the airstream. The direction of the spray was varied to make an angle of 5.8 to 18 deg with the airstream direction in order to simulate the conditions that occur when an aircraft lands in a heavy rain environment. Rainrates simulated varied from 1000 to 1200 mm/hr which are the most severe ever expected to be encountered by an aircraft over even a 30 second period. Tunnel airspeeds ranged from 85 to 125 miles per hour. The results showed that even the most severe rainrates produced a misalignment in the alpha-vane of only 1 deg away from the airstream direction. Thus for normal rain conditions experienced by landing aircraft no significant deterioration in alpha-vane performance is expected.

  5. Methodology of Computer-Aided Design of Variable Guide Vanes of Aircraft Engines

    Science.gov (United States)

    Falaleev, Sergei V.; Melentjev, Vladimir S.; Gvozdev, Alexander S.

    2016-01-01

    The paper presents a methodology which helps to avoid a great amount of costly experimental research. This methodology includes thermo-gas dynamic design of an engine and its mounts, the profiling of compressor flow path and cascade design of guide vanes. Employing a method elaborated by Howell, we provide a theoretical solution to the task of…

  6. Numerical Study of Bubble Coalescence and Breakup in the Reactor Fuel Channel with a Vaned Grid

    Directory of Open Access Journals (Sweden)

    Tenglong Cong

    2018-01-01

    Full Text Available The characteristics of bubbles of different sizes in fuel assembly are vital to two-phase flow resistance and heat transfer capacity. However, due to the swirl flow caused by the mixing vane, bubbles can crowd at the heated surface, which may anticipate the occurrence of departure from nucleation boiling. In the current work, the adiabatic two-phase flow in a simplified fuel assembly was analyzed by using the Eulerian two-fluid model and the MUSIG (MUltiple SIze Group model. This computational domain consists of two coolant channels and two sets of vaned spacers, with three sets of periodic boundary conditions at the side faces of the domain. The distributions of vapor phase and bubble diameters were obtained, based on which the effects of mixing vanes on the bubble characteristics were analyzed. Vapor phase crowded at the rod surface in the higher inlet vapor fraction case, but crowded in the channel center in the lower inlet vapor fraction cases. This work can be used as a reference for the design of mixing vanes to avoid the anticipation of departure of nucleation boiling that may be caused by unreasonable design.

  7. Tandem accelerators, 1973--1974

    International Nuclear Information System (INIS)

    Howard, F.T.

    1974-01-01

    High voltage tandem accelerators are very important instruments in the field of nuclear physics research, especially in the acceleration of heavy ions. This survey identifies 77 tandems installed in 21 countries; of these, 34 are in the United States. Most installations have supplied data sheets identifying their machines and briefly characterizing their research programs. (U.S.)

  8. MHD stability of tandem mirrors

    International Nuclear Information System (INIS)

    Poulsen, P.; Molvik, A.; Shearer, J.

    1982-01-01

    The TMX-Upgrade experiment was described, and the manner in which various plasma parameters could be affected was discussed. The initial analysis of the MHD stability of the tandem mirror was also discussed, with emphasis on the negative tandem configuration

  9. Tandems as injectors for synchrotrons

    International Nuclear Information System (INIS)

    Ruggiero, A.G.

    1993-01-01

    This is a review on the use of tandem electrostatic accelerators for injection and fitting of synchrotrons to accelerate intense beams of heavy ions to relativistic energies. The paper emphasizes the need of operating the tandems in pulsed mode for this application. It has been experimentally demonstrated that at present this type of accelerator still provides the most reliable and best performance. (orig.)

  10. Improvement of wells turbine performance by means of 3D guide vanes; Sanjigen annai hane ni yoru wells turbine seino no kaizen

    Energy Technology Data Exchange (ETDEWEB)

    Takao, M.; Kim, T.H. [Saga University, Saga (Japan); Setoguchi, T. [Saga University, Saga (Japan). Faculty of Science and Engineering; Inoue, M. [Kyushu University, Fukuoka (Japan). Faculty of Engineering

    2000-02-25

    Performance of a Wells turbine was improved by equipping 3D guide vanes before and behind a rotor. For further improvement, 3D guide vanes have been proposed in this paper. The performance of the Wells turbine with 2D and 3D guide vanes have been investigated experimentally by model testing under steady flow conditions. Then, the running and starting characteristics in irregular ocean waves have been obtained by a computer simulation. As a result, it is found that both of the running and starting characteristics of the Wells turbine with 3D guide vanes are superior to those of the turbine with 2D guide vanes. (author)

  11. X-ray tube arrangements

    International Nuclear Information System (INIS)

    Gillard, R.G.

    1980-01-01

    A technique for ensuring the rapid correction of both amplitude and offset errors in the deflectional movement of an electron beam along an X-ray emissive target is described. The movement is monitored at at least two positions during a sweep and differences, between the two movements and a desired movement, at these positions are combined in different proportions to produce a corrective servo signal. Such arrangements find application, for example, in computerised tomographic scanners. (author)

  12. JAERI tandem-accelerator and tandem-booster

    Energy Technology Data Exchange (ETDEWEB)

    Yoshida, Tadashi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1998-03-01

    In 1982, aiming at the new development of atomic energy research, the tandem accelerator of Japan Atomic Energy Research Institute (JAERI) was installed. In fiscal year 1993, the superconducting boosters which can increase the ion energy by up to 4 times were added, and the research in the region below 1000 MeV became possible. Those are electrostatic type accelerators which are easy to be used especially in basic research field, and are useful for future research. The tandem accelerator has been operated while maintaining the first class performance as the accelerator for various kinds of heavy ion beam. It has the special shape among electrostatic type accelerators, and is excellent in the easiness of control and stability. The main particulars of the tandem accelerator are shown. As for the ion sources of the tandem accelerator, three cesium sputter type ion sources are installed on two high voltage stands. The kinds of the ions which can be accelerated are mainly negative ions. As the improvement, electron cyclotron resonance (ECR) ion sources are expected to be adopted. As for the tandem boosters, the 1/4 wavelength type resonance hollow cylinder was adopted. The constitution of the tandem boosters is explained. The way of utilizing the tandem accelerator system and the aim for hereafter are reported. (K.I.)

  13. The image evaluation of iterative motion correction reconstruction algorithm PROPELLER T2-weighted imaging compared with MultiVane T2-weighted imaging

    Science.gov (United States)

    Lee, Suk-Jun; Yu, Seung-Man

    2017-08-01

    The purpose of this study was to evaluate the usefulness and clinical applications of MultiVaneXD which was applying iterative motion correction reconstruction algorithm T2-weighted images compared with MultiVane images taken with a 3T MRI. A total of 20 patients with suspected pathologies of the liver and pancreatic-biliary system based on clinical and laboratory findings underwent upper abdominal MRI, acquired using the MultiVane and MultiVaneXD techniques. Two reviewers analyzed the MultiVane and MultiVaneXD T2-weighted images qualitatively and quantitatively. Each reviewer evaluated vessel conspicuity by observing motion artifacts and the sharpness of the portal vein, hepatic vein, and upper organs. The signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were calculated by one reviewer for quantitative analysis. The interclass correlation coefficient was evaluated to measure inter-observer reliability. There were significant differences between MultiVane and MultiVaneXD in motion artifact evaluation. Furthermore, MultiVane was given a better score than MultiVaneXD in abdominal organ sharpness and vessel conspicuity, but the difference was insignificant. The reliability coefficient values were over 0.8 in every evaluation. MultiVaneXD (2.12) showed a higher value than did MultiVane (1.98), but the difference was insignificant ( p = 0.135). MultiVaneXD is a motion correction method that is more advanced than MultiVane, and it produced an increased SNR, resulting in a greater ability to detect focal abdominal lesions.

  14. Performance improvement of centrifugal compressor stage with pinched geometry or vaned diffuser

    Energy Technology Data Exchange (ETDEWEB)

    Jaatinen, A.

    2009-07-01

    Centrifugal compressors are widely used for example in refrigeration processes, the oil and gas industry, superchargers, and waste water treatment. In this work, five different vaneless diffusers and six different vaned diffusers are investigated numerically. The vaneless diffusers vary only by their diffuser width, so that four of the geometries have pinch implemented to them. Pinch means a decrease in the diffuser width. Four of the vaned diffusers have the same vane turning angle and a different number of vanes, and two have different vane turning angles. The flow solver used to solve the flow fields is Finfo, which is a Navier-Stokes solver. All the cases are modeled Chien's k-epsilon turbulence model. All five vaneless diffusers and three vaned diffusers are investigated also experimentally. For each construction, the compressor operating map is measured according to relevant standards. In addition to this, the flow fields before and after the diffuser are measured with static and total pressure, flow angle and total temperature measurements k-omega SST turbulence model. The simulation results indicate that it is possible to improve the efficiency with the pinch, and according to the numerical results, the two best geometries are the ones with most pinch at the shroud. These geometries have approximately 4 percentage points higher effciency than the unpinched vaneless diffusers. The hub pinch does not seem to have any major benefits. In general, the pinches make the flow fields before and after the diffuser more uniform. The pinch also seems to improve the impeller effciency. This is down to two reasons. The major reason is that the pinch decreases the size of slow flow and possible backflow region located near the shroud after the impeller. Secondly, the pinches decrease the flow velocity in the tip clearance, leading to a smaller tip leakage flow and therefore slightly better impeller efficiency. Also some of the vaned diffusers improve the efficiency

  15. Moduli of weighted hyperplane arrangements

    CERN Document Server

    Lahoz, Martí; Macrí, Emanuele; Stellari, Paolo

    2015-01-01

    This book focuses on a large class of geometric objects in moduli theory and provides explicit computations to investigate their families. Concrete examples are developed that take advantage of the intricate interplay between Algebraic Geometry and Combinatorics. Compactifications of moduli spaces play a crucial role in Number Theory, String Theory, and Quantum Field Theory – to mention just a few. In particular, the notion of compactification of moduli spaces has been crucial for solving various open problems and long-standing conjectures. Further, the book reports on compactification techniques for moduli spaces in a large class where computations are possible, namely that of weighted stable hyperplane arrangements.

  16. New arrangements in climate policy

    International Nuclear Information System (INIS)

    Arts, B.J.M.

    2000-01-01

    Climate policy, its content and the way it is being organised, is changing, both nationally and internationally. The Kyoto Protocol and its effects form an important catalyst for this process. The focus in climate discourse is increasingly on 'differentiation' and 'flexibilisation', while the role of the industrial sectors involved has changed since 1997, among other things expressed in the increasing influence exerted by the business community and the declining power of the environmental movement. There is a transition underway, from pluralist to private policy arrangements

  17. Arrangement for selectively irradiating webs

    International Nuclear Information System (INIS)

    Ihme, B.

    1975-01-01

    The arrangement for selectively irradiating a web includes a perforated band of a radiation impermeable substance which is guided in an endless path via a pair of guide rollers and has two juxtaposed runs in this path. A take-up roller conveys a web of material past one of the runs at a side thereof remote from the other run, the direction of movement of the web being other than parallel to that of the band and, preferably, normal thereto. An electron accelerator is provided at the far side of the run remote from the web and is effective for directing a radiation beam at the web through the perforations

  18. Package and Assisted Travel Arrangement

    Directory of Open Access Journals (Sweden)

    Ivan Tot

    2015-01-01

    Full Text Available In the ordinary legislative procedure before the European Parliament and the Council, there is a proposal of the European Commission for the adoption of a new directive that would bring the regulation of the contract on organized tours into line with current market development of organized trips. The proposal is intended to regulate the various combinations of travel services that are today offered to passengers, particularly online, which are identical or comparable to the travel services provided in a classic pre-arranged package. The subject of the paper are the provisions of the proposal of the directive which govern the field of application of the proposed directive, in particular the proposed changes regarding the concept of "package" contained in the European Commission proposal and amendments of the European Parliament, as well as the analysis of the proposed new concept of "assisted travel arrangements." The paper also critically refers to the method of targeted maximum harmonization as a proposed new intensity of the harmonization. The conclusion is that, despite the welcome updating of an outdated text of the directive on package travel which is line with the current market needs, the proposed text of the new directive is burdened with technical and complex definitions that could lead to significant difficulties in their transposition into the provisions of national law of the Member States.

  19. Radiation detector arrangements and methods

    International Nuclear Information System (INIS)

    Jackson, J.

    1989-01-01

    The patent describes a radiation detector arrangement. It comprises at least one detector element in the form of a temperature-sensitive resistor whose electrical resistance changes in response to radiation incident on the detector element, the resistor having a high positive temperature coefficient of electrical resistance at a transition in its electrical conductance, circuit means for applying a voltage across the resistor during operation of the detector arrangement, and temperature-regulation means for regulating the temperature of the resistor so as to operate the resistor in the transition, characterised in that the temperature-regulation means comprises the resistor and the circuit means which passes sufficient current through the resistor by resistance heating to a position in the transition at which a further increase in its temperature in response to incident radiation reduces the resistance heating by reducing the current, thereby stabilizing the temperature of the resistor at the position. The positive temperature coefficient at the position being sufficiently high that the change in the resistance heating produced by a change in the temperature of the resistor at the position is larger than a change in power of the incident radiation required to produce that same change in temperature of the resistor in the absence of any change in resistance heating

  20. Tandem Van de Graaff facility

    Data.gov (United States)

    Federal Laboratory Consortium — Completed in 1970, the Tandem Van de Graaff facility was for many years the world's largest electrostatic accelerator facility. It can provide researchers with beams...

  1. Potential measurements in tandem mirrors

    International Nuclear Information System (INIS)

    Glowienka, J.C.

    1985-11-01

    The US mirror program has begun conducting experiments with a thermal barrier tandem mirror configuration. This configuration requires a specific axial potential profile and implies measurements of potential for documentation and optimization of the configuration. This report briefly outlines the motivation for the thermal barrier tandem mirror and then outlines the techniques used to document the potential profile in conventional and thermal barrier tandem mirrors. Examples of typical data sets from the world's major tandem mirror experiments, TMX and TMX-U at Lawrence Livermore National Laboratory (LLNL) and Gamma 10 at Tsukuba University in Japan, and the current interpretation of the data are discussed together with plans for the future improvement of measurements of plasma potential

  2. Superconducting linacs used with tandems

    International Nuclear Information System (INIS)

    Ben-Zvi, I.

    1984-01-01

    The main features of superconducting linacs used as post-accelerators of tandems are reviewed. Various aspects of resonators, cryogenics and electronics are discussed, and recent advances in the field are presented. (orig.)

  3. The effect of grid assembly mixing vanes on critical heat flux values and azimuthal location in fuel assemblies

    International Nuclear Information System (INIS)

    De Crecy, F.

    1994-01-01

    Critical heat flux (CHF) is one of the limiting phenomena for a PWR. It has been widely studied for years, but many facts are still not satisfactorily understood. This paper deals with the effect of the grid assembly mixing vanes on both the value of the CHF and the azimuthal location of the departure from nucleate boiling (DNB). A series of experimental studies was performed on electrically heated, 5x5 square pitched, vertical rod bundles. Two specific grid assembly designs were used: with and without mixing vanes. DNB was detected by eight thermocouples welded internally in each rod at the same level in order to determine the azimuthal location. The coolant was Freon-12 flowing upwards to simulate high pressure water (as defined by Stevens). Single-phase flow experiments were also conducted to measure the exit temperature field in order to obtain the mixing coefficients for subchannel analysis.The results show very clearly that the mixing vanes have a significant effect on both the DNB azimuthal location and the CHF value. - Without mixing vanes, DNB occurs mainly on the most central rod and preferentially at the azimuthal location facing the adjacent rod. - With mixing vanes, DNB can occur on any of the nine central rods and is distributed in an apparently random way around the rod. -The effect of the mixing vanes on CHF is dramatic and depends a great deal on the parameter range (pressure, local mass velocity and local quality). Generally speaking, CHF with mixing vanes is significantly higher than without mixing vanes, but this effect can be inverted in some cases.In order to understand this fact more clearly, it is necessary to perform detailed analysis of subchannel behavior. Indeed, the analyses show that the magnitude of this effect is closely related to the mixing coefficients used. These mixing coefficients, estimated from the single-phase flow experiments, are subject to large uncertainties in two-phase flow. ((orig.))

  4. Heat transfer coefficient testing in nuclear fuel rod bundles with mixing vane grids

    International Nuclear Information System (INIS)

    Conner, Michael E.; Smith, L. David III; Holloway, Mary V.; Beasley, Donald E.

    2005-01-01

    An air heat transfer test facility was developed to test the heat transfer downstream of support grids in simulated PWR nuclear fuel rod bundles. The goal of this testing is to study the single-phase heat transfer coefficients downstream of grids with mixing vanes in a square-pitch rod bundle. The technique developed utilizes fully-heated grid spans and a specially designed thermocouple holder that can be moved axially down the rod bundle and aximuthally within a test rod. From this testing, the axial and aximuthally varying heat transfer coefficient can be determined. Different grid designs are tested and compared to determine the heat transfer enhancement associated with key grid features such as mixing vanes. (author)

  5. Aerodynamic forces estimation on jet vanes exposed to supersonic exhaust of a CD Nozzle

    International Nuclear Information System (INIS)

    Bukhari, S.B.H.; Jehan, I.; Zahir, S.; Khan, M.A.

    2003-01-01

    A comprehensive study has been made for the estimation of aerodynamic forces on the jet Vane placed in the supersonic exhaust of a Convergent Divergent, CD-Nozzle. Such a system is used to provide the control forces that consist of four orthogonal vanes mounted in the supersonic exhaust of the CD-Nozzles. The flow field parameters for a CD Nozzle were analyzed and validated earlier. In this paper the published experimental and CFD results from RAMPANT Code from Fluent Inc. were used to estimate the axial and normal forces by using PAK-3D, a Computational Fluid Dynamics (CFD) software based on Navier-Stokes Equations solver. Results got verified quantitatively with a maximum error of 8% between PAK-3D and experiment, while 4% between PAK-3D and a CFD code, RAMPANT for the axial force. (author)

  6. RF field measurement of a four-vane type RFQ with PISLs

    International Nuclear Information System (INIS)

    Ueno, A.; Yamajaki, Y.

    1992-01-01

    Field instability due to a dipole mode mixing is the most significant disadvantage of an original four-vane type radio-frequency quadrupole (RFQ) linac. In order to avoid any dipole mode mixing, several pairs of vane coupling rings (VCRs) have mainly been used so far. However the VCR has complicated shape and is difficult to fabricate, particularly in the RFQ linac operated with a high-duty factor. Thus, a new field-stabilization concept was proposed and was referred to as a π-mode stabilizing loop (PISL) in a previous paper. The results of rf characteristics measurements on a low-power model cavity with or without PISLs are presented in this paper. The measurements showed that the PISLs were capable of stabilizing the accelerating mode, reducing the ratio of a dipole mode mixing from 7% to less than 1.5% (Author) 4 figs., tab., 10 refs

  7. Tandem Terminal Ion Source

    International Nuclear Information System (INIS)

    Harper, G.C.; Lindner, C.E.; Myers, A.W.; Wechel, T.D. van

    2000-01-01

    OAK-B135 Tandem Terminal Ion Source. The terminal ion source (TIS) was used in several experiments during this reporting period, all for the 7 Be(γ) 8 B experiment. Most of the runs used 1 H + at terminal voltages from 0.3 MV to 1.5 MV. One of the runs used 2 H + at terminal voltage of 1.4 MV. The other run used 4 He + at a terminal voltage of 1.37 MV. The list of experiments run with the TIS to date is given in table 1 below. The tank was opened four times for unscheduled source repairs. On one occasion the tank was opened to replace the einzel lens power supply which had failed. The 10 kV unit was replaced with a 15 kV unit. The second time the tank was opened to repair the extractor supply which was damaged by a tank spark. On the next occasion the tank was opened to replace a source canal which had sputtered away. Finally, the tank was opened to replace the discharge bottle which had been coated with aluminum sputtered from the exit canal

  8. Tandem Terminal Ion Source

    International Nuclear Information System (INIS)

    None

    2000-01-01

    OAK-B135 Tandem Terminal Ion Source. The terminal ion source (TIS) was used in several experiments during this reporting period, all for the(sup 7)Be((gamma))(sup 8)B experiment. Most of the runs used(sup 1)H(sup+) at terminal voltages from 0.3 MV to 1.5 MV. One of the runs used(sup 2)H(sup+) at terminal voltage of 1.4 MV. The other run used(sup 4)He(sup+) at a terminal voltage of 1.37 MV. The list of experiments run with the TIS to date is given in table 1 below. The tank was opened four times for unscheduled source repairs. On one occasion the tank was opened to replace the einzel lens power supply which had failed. The 10 kV unit was replaced with a 15 kV unit. The second time the tank was opened to repair the extractor supply which was damaged by a tank spark. On the next occasion the tank was opened to replace a source canal which had sputtered away. Finally, the tank was opened to replace the discharge bottle which had been coated with aluminum sputtered from the exit canal

  9. Background noise measurements from jet exit vanes designed to reduced flow pulsations in an open-jet wind tunnel

    Science.gov (United States)

    Hoad, D. R.; Martin, R. M.

    1985-01-01

    Many open jet wind tunnels experience pulsations of the flow which are typically characterized by periodic low frequency velocity and pressure variations. One method of reducing these fluctuations is to install vanes around the perimeter of the jet exit to protrude into the flow. Although these vanes were shown to be effective in reducing the fluctuation content, they can also increase the test section background noise level. The results of an experimental acoustic program in the Langley 4- by 7-Meter Tunnel is presented which evaluates the effect on tunnel background noise of such modifications to the jet exit nozzle. Noise levels for the baseline tunnel configuration are compared with those for three jet exit nozzle modifications, including an enhanced noise reduction configuration that minimizes the effect of the vanes on the background noise. Although the noise levels for this modified vane configuration were comparable to baseline tunnel background noise levels in this facility, installation of these modified vanes in an acoustic tunnel may be of concern because the noise levels for the vanes could be well above background noise levels in a quiet facility.

  10. Analysis on influence of guide vanes closure laws of pump-turbine on load rejection transient process

    Science.gov (United States)

    Yao, Z.; Bi, H. L.; Huang, Q. S.; Li, Z. J.; Wang, Z. W.

    2013-12-01

    In load rejection transient process, the sudden shut down of guide vanes may cause units speed rise and a sharp increase in water hammer pressure of diversion system, which endangers the safety operation of the power plant. Adopting reasonable guide vane closure law is a kind of economic and effective measurement to reduce the water hammer pressure and limit rotational speed increases. In this paper, combined with Guangzhou Pumped Storage Power Station plant A, the load rejection condition under different guide vanes closure laws is calculated and the key factor of guide vanes closure laws on the impact of the load rejection transition process is analyzed. The different inflection points, which are the closure modes, on the impact of unit speed change, water level fluctuation of surge tank, and the pressure fluctuation of volute inlet and draft tube inlet are further discussed. By compared with the calculation results, a reasonable guide vanes inflection point position can be determined according to security requirements and a reasonable guide vanes closure law can be attained to effectively coordinate the unit speed rise and the rapid pressure change in the load rejection transient process.

  11. 29 CFR 779.229 - Other arrangements.

    Science.gov (United States)

    2010-07-01

    ..., Franchise and Other Business Arrangements § 779.229 Other arrangements. With respect to those arrangements...” establishment will be considered a part of the same “enterprise.” For example, whether a franchise, lease, or... the enterprise which grants the franchise, right, or concession. (S. Rept. 145, 87th Cong., 1st Sess...

  12. 42 CFR 413.241 - Pharmacy arrangements.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 2 2010-10-01 2010-10-01 false Pharmacy arrangements. 413.241 Section 413.241... Disease (ESRD) Services and Organ Procurement Costs § 413.241 Pharmacy arrangements. Effective January 1, 2011, an ESRD facility that enters into an arrangement with a pharmacy to furnish renal dialysis...

  13. MUSICAL ARRANGEMENT OF MEDIA ADS

    Directory of Open Access Journals (Sweden)

    Chernyshov Alexander V.

    2015-01-01

    Full Text Available The music-compositional principles of commercial and political advertising and also the self-promotion of electronic media (radio, television, Internet are considered in this mediatext: from the elementary beeps, symbolic functions, emblems/logos and musical brands to the sound engineering technology to underscore the product's name and the complex synthesis between music and intra movements and color-light design of frames. Simultaneously examines, how the musical arrangement of ethereal advertising is involved in creation the emotional drama or bravado which reach the level of explicit or associative counterpoint 'music with the advertised object or subject' and which extend to expression of cultural image of all the broadcast channel. The article explores the works of the next genres like infomercial, teleshopping, film-ad, and autonomous commercials that have been produced in European countries or USA.

  14. High mass isotope separation arrangement

    International Nuclear Information System (INIS)

    Eerkens, J.W.

    1976-01-01

    An isotope separation arrangement for separating a preselected isotope from a mixture of chemically-identical but isotopically-different molecules by either photon-induced pure revibrational or vibronic selective excitation of the molecules containing the atoms of the isotope to be separated from a lower to a higher energy state, and a chemical reaction of the higher energy state molecules with a chemically-reactive agent to form a chemical compound containing primarily the atoms of the isotope to be separated in a physicochemical state different from the physicochemical state of the mixture of chemically-identical but isotopically-different molecules. The chemical compound containing the atoms of the isotope to be separated may be subsequently processed to obtain the isotope. The laser configuration used to generate the photon beam is fully described

  15. International arrangements against nuclear terrorism

    International Nuclear Information System (INIS)

    Bunn, G.

    1987-01-01

    International efforts to show the spread of nuclear weapons have created an international norm of nonproliferation, backed by a variety of enforcement mechanisms. Together they are often referred to as the nonproliferation regime. This regime is reviewed, starting with the 1963 Limited Test Ban Treaty. The centerpiece of the regime, the Non-Proliferation Treaty (NPT), signed in 1968, now has 135 parties, including most of the advanced industrial nuclear countries. Results of the 1985 NPT Review Conference are briefly discussed; the 86 NPT parties that attended reaffirmed the treaty's value, pledged continued support for the IAEA safeguards system, and called upon nonsigners to renounce nuclear weapons and accept IAEA safeguards. A section is devoted to the physical protection of nuclear materials, facilities, and weapons. Finally, recommendations are presented to improve international arrangements against nuclear terrorists

  16. Importance of Grid Center Arrangement

    Science.gov (United States)

    Pasaogullari, O.; Usul, N.

    2012-12-01

    In Digital Elevation Modeling, grid size is accepted to be the most important parameter. Despite the point density and/or scale of the source data, it is freely decided by the user. Most of the time, arrangement of the grid centers are ignored, even most GIS packages omit the choice of grid center coordinate selection. In our study; importance of the arrangement of grid centers is investigated. Using the analogy between "Raster Grid DEM" and "Bitmap Image", importance of placement of grid centers in DEMs are measured. The study has been conducted on four different grid DEMs obtained from a half ellipsoid. These grid DEMs are obtained in such a way that they are half grid size apart from each other. Resulting grid DEMs are investigated through similarity measures. Image processing scientists use different measures to investigate the dis/similarity between the images and the amount of different information they carry. Grid DEMs are projected to a finer grid in order to co-center. Similarity measures are then applied to each grid DEM pairs. These similarity measures are adapted to DEM with band reduction and real number operation. One of the measures gives function graph and the others give measure matrices. Application of similarity measures to six grid DEM pairs shows interesting results. These four different grid DEMs are created with the same method for the same area, surprisingly; thirteen out of 14 measures state that, the half grid size apart grid DEMs are different from each other. The results indicated that although grid DEMs carry mutual information, they have also additional individual information. In other words, half grid size apart constructed grid DEMs have non-redundant information.; Joint Probability Distributions Function Graphs

  17. Modular arrangement of regulatory RNA elements.

    Science.gov (United States)

    Roßmanith, Johanna; Narberhaus, Franz

    2017-03-04

    Due to their simple architecture and control mechanism, regulatory RNA modules are attractive building blocks in synthetic biology. This is especially true for riboswitches, which are natural ligand-binding regulators of gene expression. The discovery of various tandem riboswitches inspired the design of combined RNA modules with activities not yet found in nature. Riboswitches were placed in tandem or in combination with a ribozyme or temperature-responsive RNA thermometer resulting in new functionalities. Here, we compare natural examples of tandem riboswitches with recently designed artificial RNA regulators suggesting substantial modularity of regulatory RNA elements. Challenges associated with modular RNA design are discussed.

  18. Combined heat and power plants with parallel tandem steam turbines; Smaaskalig kraftvaerme med parallellkopplade tandemturbiner

    Energy Technology Data Exchange (ETDEWEB)

    Steinwall, Pontus; Norstroem, Urban; Pettersson, Camilla; Oesterlin, Erik

    2004-12-01

    We investigate the technical and economical conditions for a concept with parallel coupled tandem turbines in small scale combined heat and power plants fired with bio-fuel and waste. Performance and heat production costs at varying electricity prices for the concept with two smaller tandem coupled steam turbines has been compared to the traditional concept with one single multi-staged turbine. Three different types of plants have been investigated: - Bio fuelled CHP plant with thermal capacity of 15 MW{sub th}; - Waste fired CHP plant with thermal capacity of 20 MW{sub th}; - Bio fuelled CHP plant with thermal capacity of 25 MW{sub th}. The simple steam turbines (Curtis turbines) used in the tandem arrangement has an isentropic efficiency of about 49 to 53% compared to the multi-staged steam turbines with isentropic efficiency in the range of 59% to 81%. The lower isentropic efficiency for the single staged turbines is to some extent compensated at partial load when one of the two turbines can be shut down leading to better operational conditions for the one still in operation. For concepts with saturated steam at partial load below 50% the tandem arrangements presents higher electricity efficiency than the conventional single turbine alternative. The difference in annual production of electricity is therefore less than the difference in isentropic efficiency for the two concepts. Production of electricity is between 2% and 42% lower for the tandem arrangements in this study. Investment costs for the turbine island has been calculated for the two turbine concepts and when the costs for turbines, generator, power transmission, condensing system, piping system, buildings, assembling, commissioning and engineering has been added the sum is about the same for the two concepts. For the bio-fuelled plant with thermal capacity of 15 MW{sub th} the turbine island amount to about 10-12 MSEK and about 13-15 MSEK for the waste fired plant with a thermal capacity of 20 MW

  19. Flow control in axial fan inlet guide vanes by synthetic jets

    Directory of Open Access Journals (Sweden)

    Wurst P.

    2013-04-01

    Full Text Available Tested high pressure axial flow fan with hub/tip ratio of 0.70 and external diameter of 600 mm consisted of inlet guide vanes (IGV, rotor and stator blade rows. Fan peripheral velocity was 47 m/s. Air volume flow rate was changed by turning of rear part of the inlet guide vanes. At turning of 20 deg the flow was separated on the IGV profiles. The synthetic jets were introduced through radial holes in machine casing in the location before flow separation origin. Synthetic jet actuator was designed with the use of a speaker by UT AVCR. Its membrane had diameter of 63 mm. Excitation frequency was chosen in the range of 500 Hz – 700 Hz. Synthetic jets favourably influenced separated flow on the vane profiles in the distance of (5 – 12 mm from the casing surface. The reduction of flow separation area caused in the region near the casing the decrease of the profile loss coefficient approximately by 20%.

  20. Flow control in axial fan inlet guide vanes by synthetic jets

    Science.gov (United States)

    Cyrus, V.; Trávníček, Z.; Wurst, P.; Kordík, J.

    2013-04-01

    Tested high pressure axial flow fan with hub/tip ratio of 0.70 and external diameter of 600 mm consisted of inlet guide vanes (IGV), rotor and stator blade rows. Fan peripheral velocity was 47 m/s. Air volume flow rate was changed by turning of rear part of the inlet guide vanes. At turning of 20 deg the flow was separated on the IGV profiles. The synthetic jets were introduced through radial holes in machine casing in the location before flow separation origin. Synthetic jet actuator was designed with the use of a speaker by UT AVCR. Its membrane had diameter of 63 mm. Excitation frequency was chosen in the range of 500 Hz - 700 Hz. Synthetic jets favourably influenced separated flow on the vane profiles in the distance of (5 - 12) mm from the casing surface. The reduction of flow separation area caused in the region near the casing the decrease of the profile loss coefficient approximately by 20%.

  1. A Three-Dimensional Coupled Internal/External Simulation of a Film-Cooled Turbine Vane

    Science.gov (United States)

    Heidmann, James D.; Rigby, David L.; Ameri, Ali A.

    1999-01-01

    A three-dimensional Navier-Stokes simulation has been performed for a realistic film-cooled turbine vane using the LeRC-HT code. The simulation includes the flow regions inside the coolant plena and film cooling holes in addition to the external flow. The vane is the subject of an upcoming NASA Glenn Research Center experiment and has both circular cross-section and shaped film cooling holes. This complex geometry is modeled using a multi-block grid which accurately discretizes the actual vane geometry including shaped holes. The simulation matches operating conditions for the planned experiment and assumes periodicity in the spanwise direction on the scale of one pitch of the film cooling hole pattern. Two computations were performed for different isothermal wall temperatures, allowing independent determination of heat transfer coefficients and film effectiveness values. The results indicate separate localized regions of high heat transfer coefficient values, while the shaped holes provide a reduction in heat flux through both parameters. Hole exit data indicate rather simple skewed profiles for the round holes, but complex profiles for the shaped holes with mass fluxes skewed strongly toward their leading edges.

  2. Design optimization of a T mixing vane in nuclear fuel assembly

    International Nuclear Information System (INIS)

    Jung, Sang-Ho; Moon, Mi-Ae; Kim, Kwang-Yong

    2009-01-01

    The purposes of present work are to analyze the convective heat transfer with three-dimensional Reynolds-averaged Navier-Stokes analysis, and to optimize shape of the mixing vane using the analysis results. PLUS7 that is designed by KNF and Westinghouse is used as reference geometry. Shear stress transport turbulence model is used as a turbulence closure. Two bend angles of mixing vane are selected as design variable. The objective function is defined as a combination of inverse of heat transfer rate and friction loss. Response surface method is employed as an optimization technique. The calculation domains of 1x2 geometry are analyzed with translational and rotational periodic boundary conditions which take flow directions into account. The fluid flow and heat transfer characteristics have been explained through velocity vectors, streamlines and Nusselt numbers. The results show that the optimized geometry improves the heat transfer performance of the mixing vane with a relatively small pressure drop increment and has higher Critical Heat Flux. (author)

  3. Analysis of waves in the plasma guided by a periodical vane-type slow wave structure

    International Nuclear Information System (INIS)

    Wu, T.J.; Kou, C.S.

    2005-01-01

    In this study, the dispersion relation has been derived to characterize the propagation of the waves in the plasma guided by a periodical vane-type slow wave structure. The plasma is confined by a quartz plate. Results indicate that there are two different waves in this structure. One is the plasma mode that originates from the plasma surface wave propagating along the interface between the plasma and the quartz plate, and the other is the guide mode that originally travels along the vane-type slow wave structure. In contrast to its original slow wave characteristics, the guide mode becomes a fast wave in the low-frequency portion of the passband, and there exists a cut-off frequency for the guide mode. The vane-type guiding structure has been shown to limit the upper frequency of the passband of the plasma mode, compared with that of the plasma surface wave. In addition, the passband of the plasma mode increases with the plasma density while it becomes narrower for the guide mode. The influences of the parameters of the guiding structure and plasma density on the propagation of waves are also presented

  4. V/STOL Tandem Fan transition section model test. [in the Lewis Research Center 10-by-10 foot wind tunnel

    Science.gov (United States)

    Simpkin, W. E.

    1982-01-01

    An approximately 0.25 scale model of the transition section of a tandem fan variable cycle engine nacelle was tested in the NASA Lewis Research Center 10-by-10 foot wind tunnel. Two 12-inch, tip-turbine driven fans were used to simulate a tandem fan engine. Three testing modes simulated a V/STOL tandem fan airplane. Parallel mode has two separate propulsion streams for maximum low speed performance. A front inlet, fan, and downward vectorable nozzle forms one stream. An auxilliary top inlet provides air to the aft fan - supplying the core engine and aft vectorable nozzle. Front nozzle and top inlet closure, and removal of a blocker door separating the two streams configures the tandem fan for series mode operations as a typical aircraft propulsion system. Transition mode operation is formed by intermediate settings of the front nozzle, blocker door, and top inlet. Emphasis was on the total pressure recovery and flow distortion at the aft fan face. A range of fan flow rates were tested at tunnel airspeeds from 0 to 240 knots, and angles-of-attack from -10 to 40 deg for all three modes. In addition to the model variables for the three modes, model variants of the top inlet were tested in the parallel mode only. These lip variables were: aft lip boundary layer bleed holes, and Three position turning vane. Also a bellmouth extension of the top inlet side lips was tested in parallel mode.

  5. Characteristics of Fluid Force Reduction for Two Different Square Prisms in a Tandem Arrangement

    Energy Technology Data Exchange (ETDEWEB)

    Ro, Ki Deok; Kang, Chang Whan; Park, Kwon Ho [Gyeongsang Nat’l Univ., Jinju (Korea, Republic of)

    2017-07-15

    The Characteristics of the flow fields of a square prism having a small square prism were investigated by measuring of lift and drag on the square prism and visualizing the flow field using PIV. The experimental parameters were the width ratios(H/B=0.2~0.6) of small square prisms to the prism width and the gap ratios (G/B=0~3) between the prism and the small square prism. The drag reduction rate of the square prism initially increased and then decreased with the G/B ratio for the same H/B ratio, and increased with the H/B ratio for the same G/B ratio. The maximum drag reduction rate of 98.0% was observed at H/B=0.6 and G/B=1.0. The lift reduction rate of the square prism was not affected by the width and gap ratios; the total average value was approximately 66.5%. In case of a square prism having a small square prism, the stagnation regions were represented in the upstream and downstream sides of the square prism.

  6. CODAC systems arrangement and connectivity

    Energy Technology Data Exchange (ETDEWEB)

    Gulati, Hitesh Kumar, E-mail: hkgulati@gmail.com; Beltran, David; Kuehn, Ingo; Kotamaki, Miikka; Makijarvi, Petri; Wallander, Anders

    2013-10-15

    termination point for CODAC Network infrastructure. The CODAC Network cables running from the nearest CODAC Network hutch will terminate in these panels. Network panels are installed at strategic locations close to plant system I and C cubicles. This paper will describe more details about the physical arrangement of CODAC systems in different buildings on ITER platform for different purpose and their planned connectivity. This paper will also provide more information about the volume allocations for CODAC components, planned cabling arrangement and other infrastructure requirements like electrical and cooling etc.

  7. JAERI 20 MV tandem accelerator

    International Nuclear Information System (INIS)

    Tsukada, Kineo; Harada, Kichinosuke

    1977-01-01

    Accelerators have been developed as the experimental apparatuses for the studies on nuclei and elementary particles. One direction of the development is the acceleration of protons and electrons to more and more high energy, and another direction is the acceleration of heavy ions up to uranium to several MeV up to several hundreds MeV. However recently, accelerators are used as the useful tools for the studies in wider fields. There are electrostatic acceleration and high frequency acceleration in ion acceleration, and at present, super-large accelerators are high frequency acceleration type. In Japan Atomic Energy Research Institute, it was decided in 1975 to construct an electrostatic accelerator of tandem type in order to accelerate heavy ions. In case of the electrostatic acceleration, the construction is relatively simple, the acceleration of heavy ions is easy, the property of the ion beam is very good, and the energy is stable. Especially, the tandem type is convenient for obtaining high energy. The tandem accelerator of 20 MV terminal voltage was ordered from the National Electrostatics Corp., USA, and is expected to be completed in 1978. The significance of heavy ion acceleration in the development and research of atomic energy, tandem van de Graaff accelerators, the JAERI 20MV tandem accelerator, and the research project with this accelerator are described. (Kako, I.)

  8. Transfer arrangement for sealable enclosure

    International Nuclear Information System (INIS)

    Broxup, K.H.

    1991-01-01

    An arrangement for transferring items to or from e.g. a glovebox, in a closed moveable container. The glovebox port has a door having a non-rotatable outer portion and a rotatable inner portion. The container has a lid having a non-rotatable outer portion and a rotatable inner portion, the outer portion having a thin lip. The port has a thin lip which can be aligned with the lip of the lid. The outer portion of the door retains a peripheral sealing ring and the rim of the container retains a similar ring which can sandwich and bridge the two lips. The container is attached to the port by a rotatable locking ring. Via an externally rotatable and slidable shaft, lined at its inner end to the inner portion of the door, the latter is rotatable to disengage the door from the port, couple this inner portion to that of the lid, disengage the lid from the container, and move the coupled door and lid back and laterally away from the port, and vice versa. (author)

  9. Experimental investigation of in-cylinder air flow to optimize number of helical guide vanes to enhance DI diesel engine performance using mamey sapote biodiesel

    Science.gov (United States)

    Kumar, A. Raj; Janardhana Raju, G.; Hemachandra Reddy, K.

    2018-03-01

    The current research work investigates the influence of helical guide vanes in to the intake runner of a D.I diesel engine operating by the high viscous Mamey Sapote biodiesel to enhance in-cylinder suction air flow features. Helical guide vanes of different number of vanes are produced from 3D printing and placed in the intake manifold to examine the air flow characteristics. Four different helical guide vane devices namely 3, 4, 5 and 6 vanes of the same dimensions are tested in a D.I diesel engine operating with Mamey Sapote biodiesel blend. As per the experimental results of engine performance and emission characteristics, it is found that 5 vanes helical guide vane swirl device exhibited in addition number of increased improvements such as the brake power and bake thermal efficiency by 2.4% and 8.63% respectively and the HC, NOx, Carbon monoxide and, Smoke densities are reduced by 15.62%, 4.23%, 14.27% and 9.6% at peak load operating conditions as collate with normal engine at the same load. Hence this investigation concluded that Helical Guide Vane Devices successfully enhanced the in-cylinder air flow to improve better addition of Mamey Sapote biodiesel with air leading in better performance of the engine than without vanes.

  10. Introduction to tandem mirror physics

    International Nuclear Information System (INIS)

    Kesner, J.; Gerver, M.J.; Lane, B.G.; McVey, B.D.; Catto, P.J.; D'Ippolito, D.A.; Myra, J.R.

    1983-09-01

    This monograph, prepared jointly by the MIT Plasma Fusion Center Mirror Fusion group and SAI, Boulder, Colorado, presents a review of the development of mirror fusion theory from its conception some thirty years ago to the present. Pertinent historic experiments and their contribution are discussed to set the stage for a detailed analysis of current experiments and the problems which remain to be solved in bringing tandem mirror magnetic confinement fusion to fruition. In particular, Chapter III discusses in detail the equilibrium and stability questions which must be dealt with before tandem mirror reactors become feasible, while Chapters IV and V discuss some of the current machines and those under construction which will help to resolve critical issues in both physics and engineering whose solutions are necessary to the commercialization of tandem mirror fusion

  11. Flexible Working Time Arrangements in Bulgaria

    OpenAIRE

    Beleva, Iskra

    2009-01-01

    The objective of this paper is to analyze the flexible working time arrangements in Bulgaria, using a life-course perspective. Two important features have to be outlined, namely: underdeveloped flexible forms of employment in the country, including working time arrangement, and lack of previous analysis on flexible working time arrangements from the angle of life-course perspective. The author describes the regulatory framework, collective agreements at national and company level as a frame w...

  12. Solution Structure of the Tandem Acyl Carrier Protein Domains from a Polyunsaturated Fatty Acid Synthase Reveals Beads-on-a-String Configuration

    KAUST Repository

    Trujillo, Uldaeliz

    2013-02-28

    The polyunsaturated fatty acid (PUFA) synthases from deep-sea bacteria invariably contain multiple acyl carrier protein (ACP) domains in tandem. This conserved tandem arrangement has been implicated in both amplification of fatty acid production (additive effect) and in structural stabilization of the multidomain protein (synergistic effect). While the more accepted model is one in which domains act independently, recent reports suggest that ACP domains may form higher oligomers. Elucidating the three-dimensional structure of tandem arrangements may therefore give important insights into the functional relevance of these structures, and hence guide bioengineering strategies. In an effort to elucidate the three-dimensional structure of tandem repeats from deep-sea anaerobic bacteria, we have expressed and purified a fragment consisting of five tandem ACP domains from the PUFA synthase from Photobacterium profundum. Analysis of the tandem ACP fragment by analytical gel filtration chromatography showed a retention time suggestive of a multimeric protein. However, small angle X-ray scattering (SAXS) revealed that the multi-ACP fragment is an elongated monomer which does not form a globular unit. Stokes radii calculated from atomic monomeric SAXS models were comparable to those measured by analytical gel filtration chromatography, showing that in the gel filtration experiment, the molecular weight was overestimated due to the elongated protein shape. Thermal denaturation monitored by circular dichroism showed that unfolding of the tandem construct was not cooperative, and that the tandem arrangement did not stabilize the protein. Taken together, these data are consistent with an elongated beads-on-a-string arrangement of the tandem ACP domains in PUFA synthases, and speak against synergistic biocatalytic effects promoted by quaternary structuring. Thus, it is possible to envision bioengineering strategies which simply involve the artificial linking of multiple ACP

  13. Solution Structure of the Tandem Acyl Carrier Protein Domains from a Polyunsaturated Fatty Acid Synthase Reveals Beads-on-a-String Configuration

    KAUST Repository

    Trujillo, Uldaeliz; Vá zquez-Rosa, Edwin; Oyola-Robles, Delise; Stagg, Loren J.; Vassallo, David A.; Vega, Irving E.; Arold, Stefan T.; Baerga-Ortiz, Abel

    2013-01-01

    The polyunsaturated fatty acid (PUFA) synthases from deep-sea bacteria invariably contain multiple acyl carrier protein (ACP) domains in tandem. This conserved tandem arrangement has been implicated in both amplification of fatty acid production (additive effect) and in structural stabilization of the multidomain protein (synergistic effect). While the more accepted model is one in which domains act independently, recent reports suggest that ACP domains may form higher oligomers. Elucidating the three-dimensional structure of tandem arrangements may therefore give important insights into the functional relevance of these structures, and hence guide bioengineering strategies. In an effort to elucidate the three-dimensional structure of tandem repeats from deep-sea anaerobic bacteria, we have expressed and purified a fragment consisting of five tandem ACP domains from the PUFA synthase from Photobacterium profundum. Analysis of the tandem ACP fragment by analytical gel filtration chromatography showed a retention time suggestive of a multimeric protein. However, small angle X-ray scattering (SAXS) revealed that the multi-ACP fragment is an elongated monomer which does not form a globular unit. Stokes radii calculated from atomic monomeric SAXS models were comparable to those measured by analytical gel filtration chromatography, showing that in the gel filtration experiment, the molecular weight was overestimated due to the elongated protein shape. Thermal denaturation monitored by circular dichroism showed that unfolding of the tandem construct was not cooperative, and that the tandem arrangement did not stabilize the protein. Taken together, these data are consistent with an elongated beads-on-a-string arrangement of the tandem ACP domains in PUFA synthases, and speak against synergistic biocatalytic effects promoted by quaternary structuring. Thus, it is possible to envision bioengineering strategies which simply involve the artificial linking of multiple ACP

  14. Solution structure of the tandem acyl carrier protein domains from a polyunsaturated fatty acid synthase reveals beads-on-a-string configuration.

    Directory of Open Access Journals (Sweden)

    Uldaeliz Trujillo

    Full Text Available The polyunsaturated fatty acid (PUFA synthases from deep-sea bacteria invariably contain multiple acyl carrier protein (ACP domains in tandem. This conserved tandem arrangement has been implicated in both amplification of fatty acid production (additive effect and in structural stabilization of the multidomain protein (synergistic effect. While the more accepted model is one in which domains act independently, recent reports suggest that ACP domains may form higher oligomers. Elucidating the three-dimensional structure of tandem arrangements may therefore give important insights into the functional relevance of these structures, and hence guide bioengineering strategies. In an effort to elucidate the three-dimensional structure of tandem repeats from deep-sea anaerobic bacteria, we have expressed and purified a fragment consisting of five tandem ACP domains from the PUFA synthase from Photobacterium profundum. Analysis of the tandem ACP fragment by analytical gel filtration chromatography showed a retention time suggestive of a multimeric protein. However, small angle X-ray scattering (SAXS revealed that the multi-ACP fragment is an elongated monomer which does not form a globular unit. Stokes radii calculated from atomic monomeric SAXS models were comparable to those measured by analytical gel filtration chromatography, showing that in the gel filtration experiment, the molecular weight was overestimated due to the elongated protein shape. Thermal denaturation monitored by circular dichroism showed that unfolding of the tandem construct was not cooperative, and that the tandem arrangement did not stabilize the protein. Taken together, these data are consistent with an elongated beads-on-a-string arrangement of the tandem ACP domains in PUFA synthases, and speak against synergistic biocatalytic effects promoted by quaternary structuring. Thus, it is possible to envision bioengineering strategies which simply involve the artificial linking of

  15. Living Arrangements of Young Adults in Europe

    Directory of Open Access Journals (Sweden)

    Katrin Schwanitz

    2015-12-01

    Full Text Available Comparative research suggests that there are great cross-national and cross-temporal differences in living arrangements of young adults aged 18-34 in Europe. In this paper, we examine young adults’ living arrangements (1 across several European countries and different national contexts, and (2 by taking into account cross-time variability. In doing so, we pay careful attention to a comprehensive conceptualisation of living arrangements (including extended and non-family living arrangements. The aim of this paper is to deepen our understanding of family structure and household arrangements in Europe by examining and mapping the cross-national and cross-temporal variety of young adults’ living arrangements. For our analysis we use data from the Integrated Public Use Microdata Series International (IPUMSi for the census rounds 1980, 1990, and 2000 for eight European countries (Austria, France, Greece, Hungary, Ireland, Portugal, Romania, and Switzerland. We employ log-linear models to ascertain the influence of individual and contextual factors on living arrangements. The analyses lend further support to a North/West – South/East divide in living arrangements and general gender differentials in extended family living. Other interesting results are the heterogeneity in the living arrangements of single mothers across geographic areas, and the upward trend of extended household living for young men and women between 1980 and 2000.

  16. Evolution of the Fusion Power Demonstration tandem mirror reactor configuration

    International Nuclear Information System (INIS)

    O'Toole, J.A.; Lousteau, D.C.

    1985-01-01

    This paper gives a presentation of the evolution of configurations proposed for tandem mirror Fusion Power Demonstration (FPD) machines. The FPD study was undertaken to scope the mission as well as the technical and design requirements of the next tandem mirror device. Three configurations, entitled FPD I, II, and III were studied. During this process new systems were conceived and integrated into the design, resulting in a significantly changed overall machine configuration. The machine can be divided into two areas. A new center cell configuration, minimizing magnetic field ripple and thus maximizing center cell fusion power, features a semicontinuous solenoid. A new end cell has evolved which maintains the required thermal barrier in a significantly reduced axial length. The reduced end cell effective length leads to a shorter central cell length being required to obtain minimum ignition conditions. Introduced is the concept of an electron mantle stabilized octopole arrangement. The engineering features of the new end cell and maintenance concepts developed are influenced to a great extent by the octopole-based design. The new ideas introduced during the FPD study have brought forth a new perspective of the size, design, and maintenance of tandem mirror reactors, making them more attractive as commercial power sources

  17. Tandem collimators for the JET tangential gamma-ray spectrometer

    International Nuclear Information System (INIS)

    Soare, Sorin; Balshaw, Nick; Blanchard, Patrick; Craciunescu, Teddy; Croft, David; Curuia, Marian; Edlington, Trevor; Kiptily, Vasily; Murari, Andrea; Prior, Phil; Sanders, Steven; Syme, Brian; Zoita, Vasile

    2011-01-01

    The tangential gamma-ray spectrometer (TGRS) of the JET tokamak fusion facility is an important diagnostics for investigating the fast particle evolution. A well defined field of view for the TGRS diagnostics is essential for its proper operation and this is to be determined by a rather complex system of collimators and shields both for the neutron and gamma radiations. A conceptual design for this system has been carried out with the main design target set to maximize the signal-to-background ratio at the spectrometer detector, the ratio being defined in terms of the plasma emitted gamma radiation and the gamma-ray background. As a first phase of the TGRS diagnostics upgrade a set of two tandem collimators has been designed with the aim of determining a quasi-tangential field of view through JET tokamak plasmas. A modular design of the tandem system has been developed in order to allow for the construction of different configurations for deuterium and deuterium-tritium discharges. The internal structure of the collimators consists of nuclear grade lead and high density polyethylene slabs arranged in an optimized pattern. The performance of a simplified geometry of the tandem collimator configuration has been evaluated by neutron and photon transport calculations and the numerical results show that the design parameters can be attained.

  18. A novel thermally driven rotor-vane/pressure-exchange ejector refrigeration system with environmental benefits and energy efficiency

    International Nuclear Information System (INIS)

    Hong, W.J.; Alhussan, Khaled; Zhang Hongfang; Garris, Charles A.

    2004-01-01

    The latest results of an ongoing coordinated experimental and computational program on the design and performance of a novel supersonic rotor-vane/pressure-exchange ejector for thermally driven ejector refrigeration systems are presented. For the supersonic rotor-vane/pressure-exchange ejector, careful management of the entropy rise through the oblique shocks and boundary layers is required for obtaining an advance in ejector performance. Since the invention of this new ejector is quite recent, understanding its aerodynamics, with the consequent optimization of performance, is in the formative stage. This paper shows how the supersonic aerodynamics is managed to provide the desirable flow induction characteristics through computational study and, in parallel, experimental results including flow visualization showing actual behavior with different-shaped rotor vanes. The importance of the existence of the tail part with a long expansion ramp, the sharp leading edge such as knife-edge, the proper height of leading edges, for the overall shape of rotor vane, were observed. Also the larger spin-angle rotor vane produces better flow induction and mixing between primary flow and secondary flow

  19. Hydraulic analysis of river training cross-vanes as part of post-restoration monitoring

    Directory of Open Access Journals (Sweden)

    T. A. Endreny

    2011-07-01

    Full Text Available River restoration design methods are incrementally improved by studying and learning from monitoring data in previous projects. In this paper we report post-restoration monitoring data and simulation analysis for a Natural Channel Design (NCD restoration project along 1600 m of the Batavia Kill (14 km2 watershed in the Catskill Mountains, NY. The restoration project was completed in 2002 with goals to reduce bank erosion and determine the efficacy of NCD approaches for restoring headwater streams in the Catskill Mountains, NY. The NCD approach used a reference-reach to determine channel form, empirical relations between the project site and reference site bankfull dimensions to size channel geometry, and hydraulic and sediment computations based on a bankfull (1.3 yr return interval discharge to test channel capacity and sediment stability. The NCD project included 12 cross-vanes and 48 j-hook vanes as river training structures along 19 meander bends to protect against bank erosion and maintain scour pools for fish habitat. Monitoring data collected from 2002 to 2004 were used to identify aggradation of pools in meander bends and below some structures. Aggradation in pools was attributed to the meandering riffle-pool channel trending toward step-pool morphology and cross-vane arms not concentrating flow in the center of the channel. The aggradation subsequently caused flow splitting and 4 partial point bar avulsions during a spring 2005 flood with a 25-yr return interval. Processing the pre-flood monitoring data with hydraulic analysis software provided clues the reach was unstable and preventative maintenance was needed. River restoration and monitoring teams should be trained in robust hydraulic analytical methods that help them extend project restoration goals and structure stability.

  20. Correlation analysis of fracture arrangement in space

    Science.gov (United States)

    Marrett, Randall; Gale, Julia F. W.; Gómez, Leonel A.; Laubach, Stephen E.

    2018-03-01

    We present new techniques that overcome limitations of standard approaches to documenting spatial arrangement. The new techniques directly quantify spatial arrangement by normalizing to expected values for randomly arranged fractures. The techniques differ in terms of computational intensity, robustness of results, ability to detect anti-correlation, and use of fracture size data. Variation of spatial arrangement across a broad range of length scales facilitates distinguishing clustered and periodic arrangements-opposite forms of organization-from random arrangements. Moreover, self-organized arrangements can be distinguished from arrangements due to extrinsic organization. Traditional techniques for analysis of fracture spacing are hamstrung because they account neither for the sequence of fracture spacings nor for possible coordination between fracture size and position, attributes accounted for by our methods. All of the new techniques reveal fractal clustering in a test case of veins, or cement-filled opening-mode fractures, in Pennsylvanian Marble Falls Limestone. The observed arrangement is readily distinguishable from random and periodic arrangements. Comparison of results that account for fracture size with results that ignore fracture size demonstrates that spatial arrangement is dominated by the sequence of fracture spacings, rather than coordination of fracture size with position. Fracture size and position are not completely independent in this example, however, because large fractures are more clustered than small fractures. Both spatial and size organization of veins here probably emerged from fracture interaction during growth. The new approaches described here, along with freely available software to implement the techniques, can be applied with effect to a wide range of structures, or indeed many other phenomena such as drilling response, where spatial heterogeneity is an issue.

  1. JAERI tandem annual report, 1982

    International Nuclear Information System (INIS)

    Harada, Kichinosuke; Maruyama, Michio; Ozawa, Kunio; Shikazono, Naomoto; Tamura, Tsutomu; Tanaka, Shigeya

    1983-06-01

    This annual report describes research activities which have been performed with JAERI tandem accelerator from September 1, 1981 to March 31, 1983. Summary reports of 38 papers, publications, personnel and a list of co-operative researches with universities are contained. (author)

  2. JAERI Tandem annual report 1983

    International Nuclear Information System (INIS)

    Harada, Kichinosuke; Maruyama, Michio; Okashita, Hiroshi; Ozawa, Kunio; Shikazono, Naomoto; Tanaka, Shigeya

    1984-07-01

    This annual report describes research activities which have been performed with JAERI tandem accelerator from April 1, 1983 to March 31, 1984. Summary reports of 32 papers, publications, personnel and a list of co-operative reserches with universities are contained. (author)

  3. Status of tandem mirror theory

    International Nuclear Information System (INIS)

    Baldwin, D.E.

    1979-01-01

    This report contains the text and slides used for the review talk on tandem mirror theory presented at the meeting of the Division of Plasma Physics, A.P.S., Boston, MA, November 12-16, 1979. Topics covered include classical confinement, equilibria, MHD- and micro-stability, radial transport, and thermal barriers

  4. Living arrangements of young adults in Europe

    NARCIS (Netherlands)

    Schwanitz, Katrin; Mulder, Clara H.

    2015-01-01

    Comparative research suggests that there are great cross-national and cross-temporal differences in living arrangements of young adults aged 18-34 in Europe. In this paper, we examine young adults’ living arrangements (1) across several European countries and different national contexts, and (2) by

  5. Contingent and Alternative Work Arrangements, Defined.

    Science.gov (United States)

    Polivka, Anne E.

    1996-01-01

    Discusses the definitions of contingent workers and alternative work arrangements used by the Bureau of Labor Statistics to analyze data, and presents aggregate estimates of the number of workers in each group. Discusses the overlap between contingent workers and workers in alternative arrangements. (Author/JOW)

  6. 78 FR 40131 - Proposed Subsequent Arrangement

    Science.gov (United States)

    2013-07-03

    ... INFORMATION: This subsequent arrangement concerns the retransfer of 302,188 kg of U.S.-origin natural uranium..., Saskatchewan, Canada, to Springfields Fuels Ltd. in Lancashire, United Kingdom. The material, which is... arrangement concerning the retransfer of nuclear material of United States origin will not be inimical to the...

  7. Introduction on KPS's maintenance experience of the swirl vane assemblies of primary separators for SG model F in Korea

    International Nuclear Information System (INIS)

    Kim, Yong tae

    2003-01-01

    Recently, we had experienced to replace the Swirl Vane Assemblies of primary moisture separator for SG model F in Korea because of serious degradation (Thinning) in carbon steel swirl vane blades and carbon steel separator barrel wall adjacent to swirl vane blades. When the symptom was observed by us at the first time on the swirl vane assemblies, there were small or a bit clear erosion / or corrosion marks on the edge regions of the blades but within 3 cycles of operation, we found that those marks became holes which penetrated the most of swirl vane assemblies and even more seriously, some parts of the assemblies were worn-out. Therefore, we concluded that the speed of degradation would be very rapid and serious from the beginning stage. It had been assumed that these kinds of thinning problems would be due to FAC(Flow Accelerated Corrosion) because the plants having these problems are using a highly concentrated hydrazine for the water treatment of secondary side which lead to reduce the oxygen and pH in the water. What are more serious reasons will be that the swirl vane assemblies are very weak to FAC because they were made by a low concentrated chromium carbon steel and the assemblies would have to be under the operation conditions of the highly turbulent steam-water mixed fluid with the operating temperature of higher than 280 .deg. C. Potentially, the damaged swirl vane assemblies of the primary moisture separator may create bad influences for the plant operation because it may cause the rupture of SG Tubes and over-exceed fluid influx onto the turbine and etc. KPS had successfully performed the replacement of the degraded swirl vane assemblies through our own planning and preparation. This was the unique case in all over the world and I would like to introduce you about our unique repair experience to prepare an expected future situation as we see the similar problems in other model F SGs operating in Korea

  8. An analytical model for droplet separation in vane separators and measurements of grade efficiency and pressure drop

    International Nuclear Information System (INIS)

    Koopman, Hans K.; Köksoy, Çağatay; Ertunç, Özgür; Lienhart, Hermann; Hedwig, Heinz; Delgado, Antonio

    2014-01-01

    Highlights: • An analytical model for efficiency is extended with additional geometrical features. • A simplified and a novel vane separator design are investigated experimentally. • Experimental results are significantly affected by re-entrainment effects. • Outlet droplet size spectra are accurately predicted by the model. • The improved grade efficiency doubles the pressure drop. - Abstract: This study investigates the predictive power of analytical models for the droplet separation efficiency of vane separators and compares experimental results of two different vane separator geometries. The ability to predict the separation efficiency of vane separators simplifies their design process, especially when analytical research allows the identification of the most important physical and geometrical parameters and can quantify their contribution. In this paper, an extension of a classical analytical model for separation efficiency is proposed that accounts for the contributions provided by straight wall sections. The extension of the analytical model is benchmarked against experiments performed by Leber (2003) on a single stage straight vane separator. The model is in very reasonable agreement with the experimental values. Results from the analytical model are also compared with experiments performed on a vane separator of simplified geometry (VS-1). The experimental separation efficiencies, computed from the measured liquid mass balances, are significantly below the model predictions, which lie arbitrarily close to unity. This difference is attributed to re-entrainment through film detachment from the last stage of the vane separators. After adjustment for re-entrainment effects, by applying a cut-off filter to the outlet droplet size spectra, the experimental and theoretical outlet Sauter mean diameters show very good agreement. A novel vane separator geometry of patented design (VS-2) is also investigated, comparing experimental results with VS-1

  9. A study of reflex tandem accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Nakajima, Takao; Morinobu, Shunpei; Gono, Yasuyuki; Sagara, Kenji; Sugimitsu, Tsuyoshi; Mitarai, Shiro; Nakamura, Hiroyuki; Ikeda, Nobuo; Morikawa, Tsuneyasu [Kyushu Univ., Fukuoka (Japan). Faculty of Science

    1996-12-01

    An investigation on `developing research theme and its realizing experimental apparatus` based on the tandem accelerator facility is executed. At a standpoint of recognition on essentiality of preparation, improvement or novel technical development capable of extreme increase in capacity of the tandem accelerator facility to form COE with high uniqueness, proposal of numerous ideas and their investigations and searches were conducted. In this paper, consideration results of `beam reacceleration using tandem accelerator` were shown as follows: (1) Short life unstable nuclei formed by nuclear reaction using tandem acceleration primary beam is ionized to negative and to reaccelerate by using the same tandem accelerator. And (2) by combination of plural electrons with the tandem primary accelerated beam, numbers of charge is reduced to reaccelerate by the tandem. (G.K.)

  10. Automatic efficiency optimization of an axial compressor with adjustable inlet guide vanes

    Science.gov (United States)

    Li, Jichao; Lin, Feng; Nie, Chaoqun; Chen, Jingyi

    2012-04-01

    The inlet attack angle of rotor blade reasonably can be adjusted with the change of the stagger angle of inlet guide vane (IGV); so the efficiency of each condition will be affected. For the purpose to improve the efficiency, the DSP (Digital Signal Processor) controller is designed to adjust the stagger angle of IGV automatically in order to optimize the efficiency at any operating condition. The A/D signal collection includes inlet static pressure, outlet static pressure, outlet total pressure, rotor speed and torque signal, the efficiency can be calculated in the DSP, and the angle signal for the stepping motor which control the IGV will be sent out from the D/A. Experimental investigations are performed in a three-stage, low-speed axial compressor with variable inlet guide vanes. It is demonstrated that the DSP designed can well adjust the stagger angle of IGV online, the efficiency under different conditions can be optimized. This establishment of DSP online adjustment scheme may provide a practical solution for improving performance of multi-stage axial flow compressor when its operating condition is varied.

  11. Mapping of the lateral flow field in typical subchannels of a support grid with vanes

    International Nuclear Information System (INIS)

    McClusky, Heather L.; Holloway, Mary V.; Conover, Timothy A.; Beasley, Donald E.; Conner, Michael E.; Smith III, L. David

    2003-01-01

    Lateral flow fields in four subchannels of a model rod bundle fuel assembly are measured using particle image velocimetry. Vanes (split-vane pairs) are located on the downstream edge of the support grids in the rod bundle fuel assembly and generate swirling flow. Measurements are acquired at a nominal Reynolds number of 28,000 and for seven streamwise locations ranging from 1.4 to 17.0 hydraulic diameters downstream of the grid. The streamwise development of the lateral flow field is divided into two regions based on the lateral flow structure. In Region I, multiple vortices are present in the flow field and vortex interactions occur. Either a single circular vortex or a hairpin shaped flow structure is formed in Region II. Lateral kinetic energy, maximum lateral velocity, centroid of vorticity, radial profiles of azimuthal velocity, and angular momentum are employed as measures of the streamwise development of the lateral flow field. The particle image velocimetry measurements of the present study are compared with laser doppler velocimetry measurements taken for the identical support grids and flow condition. (author)

  12. Proposal of a novel compact P-band magnetically insulated transmission line oscillator with inclined vanes

    Science.gov (United States)

    Zhang, Xiaoping; Dang, Fangchao; Li, Yangmei; Jin, Zhenxing

    2015-06-01

    In this paper, we present a novel compact P-band magnetically insulated transmission line oscillator (MILO) with specially inclined slow-wave-structure (SWS) vanes to decrease its total dimension and weight. The dispersion characteristics of the inclined SWS are investigated in detail and made comparisons with that of the traditional straight SWS. The results show that the inclined SWS is more advantageous in operating on a steady frequency in a wide voltage range and has a better asymmetric mode segregation and a relatively large band-gap between the TM00 and TM01 modes which are in favor of avoiding the asymmetric and transverse mode competition. Besides, the transverse dimension of the proposed novel inclined SWS with the same operation frequency is decreased by about 50%, and correspondingly the device volume shrinks remarkably to its 0.35 times. In particle-in-cell simulation, the electron bunching spokes are obviously formed in the inclined SWS, and a P-band high-power microwave with a power of 5.8 GW, frequency of 645 MHz, and efficiency of 17.2% is generated by the proposed device, which indicates the feasibility of the compact design with the inclined vanes at the P-band.

  13. Numerical Investigations of Unsteady Flow in a Centrifugal Pump with a Vaned Diffuser

    Directory of Open Access Journals (Sweden)

    Olivier Petit

    2013-01-01

    Full Text Available Computational fluid dynamics (CFD analyses were made to study the unsteady three-dimensional turbulence in the ERCOFTAC centrifugal pump test case. The simulations were carried out using the OpenFOAM Open Source CFD software. The test case consists of an unshrouded centrifugal impeller with seven blades and a radial vaned diffuser with 12 vanes. A large number of measurements are available in the radial gap between the impeller and the diffuse, making this case ideal for validating numerical methods. Results of steady and unsteady calculations of the flow in the pump are compared with the experimental ones, and four different turbulent models are analyzed. The steady simulation uses the frozen rotor concept, while the unsteady simulation uses a fully resolved sliding grid approach. The comparisons show that the unsteady numerical results accurately predict the unsteadiness of the flow, demonstrating the validity and applicability of that methodology for unsteady incompressible turbomachinery flow computations. The steady approach is less accurate, with an unphysical advection of the impeller wakes, but accurate enough for a crude approximation. The different turbulence models predict the flow at the same level of accuracy, with slightly different results.

  14. MATHEMATICAL MODEL FOR THE STUDY AND DESIGN OF A ROTARY-VANE GAS REFRIGERATION MACHINE

    Directory of Open Access Journals (Sweden)

    V. V. Trandafilov

    2016-08-01

    Full Text Available This paper presents a mathematical model of calculating the main parameters the operating cycle, rotary-vane gas refrigerating machine that affect installation, machine control and working processes occurring in it at the specified criteria. A procedure and a graphical method for the rotary-vane gas refrigerating machine (RVGRM are proposed. A parametric study of the main geometric variables and temperature variables on the thermal behavior of the system is analyzed. The model considers polytrope index for the compression and expansion in the chamber. Graphs of the pressure and temperature in the chamber of the angle of rotation of the output shaft are received. The possibility of inclusion in the cycle regenerative heat exchanger is appreciated. The change of the coefficient of performance machine after turning the cycle regenerative heat exchanger is analyzed. It is shown that the installation of a regenerator RVGRM cycle results in increased COP more than 30%. The simulation results show that the proposed model can be used to design and optimize gas refrigerator Stirling.

  15. Cooling Strategies for Vane Leading Edges in a Syngas Environment Including Effects of Deposition and Turbulence

    Energy Technology Data Exchange (ETDEWEB)

    Ames, Forrest [Univ. of North Dakota, Grand Forks, ND (United States); Bons, Jeffrey [Univ. of North Dakota, Grand Forks, ND (United States)

    2014-09-30

    The Department of Energy has goals to move land based gas turbine systems to alternate fuels including coal derived synthetic gas and hydrogen. Coal is the most abundant energy resource in the US and in the world and it is economically advantageous to develop power systems which can use coal. Integrated gasification combined cycles are (IGCC) expected to allow the clean use of coal derived fuels while improving the ability to capture and sequester carbon dioxide. These cycles will need to maintain or increase turbine entry temperatures to develop competitive efficiencies. The use of coal derived syngas introduces a range of potential contaminants into the hot section of the gas turbine including sulfur, iron, calcium, and various alkali metals. Depending on the effectiveness of the gas clean up processes, there exists significant likelihood that the remaining materials will become molten in the combustion process and potentially deposit on downstream turbine surfaces. Past evidence suggests that deposition will be a strong function of increasing temperature. Currently, even with the best gas cleanup processes a small level of particulate matter in the syngas is expected. Consequently, particulate deposition is expected to be an important consideration in the design of turbine components. The leading edge region of first stage vanes most often have higher deposition rates than other areas due to strong fluid acceleration and streamline curvature in the vicinity of the surface. This region remains one of the most difficult areas in a turbine nozzle to cool due to high inlet temperatures and only a small pressure ratio for cooling. The leading edge of a vane often has relatively high heat transfer coefficients and is often cooled using showerhead film cooling arrays. The throat of the first stage nozzle is another area where deposition potentially has a strongly adverse effect on turbine performance as this region meters the turbine inlet flow. Based on roughness

  16. Advanced astigmatism-corrected tandem Wadsworth mounting for small-scale spectral broadband imaging spectrometer.

    Science.gov (United States)

    Lei, Yu; Lin, Guan-yu

    2013-01-01

    Tandem gratings of double-dispersion mount make it possible to design an imaging spectrometer for the weak light observation with high spatial resolution, high spectral resolution, and high optical transmission efficiency. The traditional tandem Wadsworth mounting is originally designed to match the coaxial telescope and large-scale imaging spectrometer. When it is used to connect the off-axis telescope such as off-axis parabolic mirror, it presents lower imaging quality than to connect the coaxial telescope. It may also introduce interference among the detector and the optical elements as it is applied to the short focal length and small-scale spectrometer in a close volume by satellite. An advanced tandem Wadsworth mounting has been investigated to deal with the situation. The Wadsworth astigmatism-corrected mounting condition for which is expressed as the distance between the second concave grating and the imaging plane is calculated. Then the optimum arrangement for the first plane grating and the second concave grating, which make the anterior Wadsworth condition fulfilling each wavelength, is analyzed by the geometric and first order differential calculation. These two arrangements comprise the advanced Wadsworth mounting condition. The spectral resolution has also been calculated by these conditions. An example designed by the optimum theory proves that the advanced tandem Wadsworth mounting performs excellently in spectral broadband.

  17. Exchange rate arrangements: From extreme to "normal"

    Directory of Open Access Journals (Sweden)

    Beker Emilija

    2006-01-01

    Full Text Available The paper studies theoretical and empirical location dispersion of exchange rate arrangements - rigid-intermediate-flexible regimes, in the context of extreme arrangements of a currency board, dollarization and monetary union moderate characteristics of intermediate arrangements (adjustable pegs crawling pegs and target zones and imperative-process "normalization" in the form of a managed or clean floating system. It is established that de iure and de facto classifications generate "fear of floating" and "fear of pegging". The "impossible trinity" under the conditions of capital liberalization and globalization creates a bipolar view or hypothesis of vanishing intermediate exchange rate regimes.

  18. Tandem electrostatic accelerators for BNCT

    International Nuclear Information System (INIS)

    Ma, J.C.

    1994-01-01

    The development of boron neutron capture therapy (BNCT) into a viable therapeutic modality will depend, in part, on the availability of suitable neutron sources compatible with installation in a hospital environment. Low-energy accelerator-based intense neutron sources, using electrostatic or radio frequency quadrupole proton accelerators have been suggested for this purpose and are underdevelopment at several laboratories. New advances in tandem electrostatic accelerator technology now allow acceleration of the multi-milliampere proton beams required to produce therapeutic neutron fluxes for BNCT. The relatively compact size, low weight and high power efficiency of these machines make them particularly attractive for installation in a clinical or research facility. The authors will describe the limitations on ion beam current and available neutron flux from tandem accelerators relative to the requirements for BNCT research and therapy. Preliminary designs and shielding requirements for a tandern accelerator-based BNCT research facility will also be presented

  19. MINIMARS tandem mirror reactor study

    International Nuclear Information System (INIS)

    Perkins, L.J.; Logan, B.G.; Doggett, J.N.

    1986-01-01

    During 1985-1986, Lawrence Livermore National Lab., in partnership with the Fusion Engineering Design Center of Oak Ridge National Lab., the Univ. of Wisconsin, TRW, Grumman Aerospace Corporation, General Dynamics/Convair, Argonne National Lab., and the Canadian Fusion Fuels Technology Project, has conducted the conceptual design of MINIMARS, a small commercial tandem mirror reactor with novel octopole end plugs. With a net electric output of 600 MW(e), MINIMARS is expressly designed for short (∼4- to 5-yr) construction time, factory-built modules, and a passively safe blanket and thermal cycle. In this way, we intend to achieve a small reactor based on the tandem mirror principle that will minimize utility financial risk, thereby providing an attractive alternative to the more conventional large fusion plant designs encountered to date

  20. "Nanocrystal bilayer for tandem catalysis"

    Energy Technology Data Exchange (ETDEWEB)

    Yamada, Yusuke; Tsung, Chia Kuang; Huang, Wenyu; Huo, Ziyang; E.Habas, Susan E; Soejima, Tetsuro; Aliaga, Cesar E; Samorjai, Gabor A; Yang, Peidong

    2011-01-24

    Supported catalysts are widely used in industry and can be optimized by tuning the composition and interface of the metal nanoparticles and oxide supports. Rational design of metal-metal oxide interfaces in nanostructured catalysts is critical to achieve better reaction activities and selectivities. We introduce here a new class of nanocrystal tandem catalysts that have multiple metal-metal oxide interfaces for the catalysis of sequential reactions. We utilized a nanocrystal bilayer structure formed by assembling platinum and cerium oxide nanocube monolayers of less than 10 nm on a silica substrate. The two distinct metal-metal oxide interfaces, CeO2-Pt and Pt-SiO2, can be used to catalyse two distinct sequential reactions. The CeO2-Pt interface catalysed methanol decomposition to produce CO and H2, which were subsequently used for ethylene hydroformylation catalysed by the nearby Pt-SiO2 interface. Consequently, propanal was produced selectively from methanol and ethylene on the nanocrystal bilayer tandem catalyst. This new concept of nanocrystal tandem catalysis represents a powerful approach towards designing high-performance, multifunctional nanostructured catalysts

  1. Flood risk governance arrangements in Europe

    Science.gov (United States)

    Matczak, P.; Lewandowski, J.; Choryński, A.; Szwed, M.; Kundzewicz, Z. W.

    2015-06-01

    The STAR-FLOOD (Strengthening and Redesigning European Flood Risk Practices Towards Appropriate and Resilient Flood Risk Governance Arrangements) project, funded by the European Commission, investigates strategies for dealing with flood risk in six European countries: Belgium, the UK, France, the Netherlands, Poland and Sweden and in 18 vulnerable urban regions in these countries. The project aims to describe, analyse, explain, and evaluate the main similarities and differences between the selected EU Member States in terms of development and performance of flood risk governance arrangements. It also discusses the scientific and societal importance of these similarities and differences. Attention is paid to identification and characterization of shifts in flood risk governance arrangements and in flood risk management strategies and to determination of triggering factors and restraining factors. An assessment of a change of resilience and appropriateness (legitimacy, effectiveness, efficiency) of flood risk governance arrangements in Poland is presented and comparison with other European countries is offered.

  2. Percentage compensation arrangements: suspect, but not illegal.

    Science.gov (United States)

    Fedor, F P

    2001-01-01

    Percentage compensation arrangements, in which a service is outsourced to a contractor that is paid in accordance with the level of its performance, are widely used in many business sectors. The HHS Office of Inspector General (OIG) has shown concern that these arrangements in the healthcare industry may offer incentives for the performance of unnecessary services or cause false claims to be made to Federal healthcare programs in violation of the antikickback statute and the False Claims Act. Percentage compensation arrangements can work and need not run afoul of the law as long as the healthcare organization carefully oversees the arrangement and sets specific safeguards in place. These safeguards include screening contractors, carefully evaluating their compliance programs, and obligating them contractually to perform within the limits of the law.

  3. Flood risk governance arrangements in Europe

    Directory of Open Access Journals (Sweden)

    P. Matczak

    2015-06-01

    Full Text Available The STAR-FLOOD (Strengthening and Redesigning European Flood Risk Practices Towards Appropriate and Resilient Flood Risk Governance Arrangements project, funded by the European Commission, investigates strategies for dealing with flood risk in six European countries: Belgium, the UK, France, the Netherlands, Poland and Sweden and in 18 vulnerable urban regions in these countries. The project aims to describe, analyse, explain, and evaluate the main similarities and differences between the selected EU Member States in terms of development and performance of flood risk governance arrangements. It also discusses the scientific and societal importance of these similarities and differences. Attention is paid to identification and characterization of shifts in flood risk governance arrangements and in flood risk management strategies and to determination of triggering factors and restraining factors. An assessment of a change of resilience and appropriateness (legitimacy, effectiveness, efficiency of flood risk governance arrangements in Poland is presented and comparison with other European countries is offered.

  4. Renewable energy and Scottish trading arrangements

    International Nuclear Information System (INIS)

    2001-01-01

    This report summarises the findings of a project involving the participation of the Scottish Renewables Forum (SRF) in the ongoing Ofgem consultation process concerning the future electricity trading arrangements in Scotland. The present administrative arrangements, the activities of the SRF, the prospects for the British Electricity Trading and Transmission Arrangements (BETTA), generator connection policy, and transmission access are discussed, and an overview of consultations relating to Scotland-England interconnection access is presented. The appendices cover the SRF responses to the Ofgem consultation, a discussion paper in advance of the SRF meeting with Ofgem in April 2001, an SRF trading update, the SRF's responses to Ofgem's Environmental Action Plan, the Scottish Embedded Generators Working Group's terms of reference and draft paper on issues, and a briefing on prices in administered arrangements

  5. Peak load arrangements : Assessment of Nordel guidelines

    Energy Technology Data Exchange (ETDEWEB)

    2009-07-01

    Two Nordic countries, Sweden and Finland, have legislation that empowers the TSO to acquire designated peak load resources to mitigate the risk for shortage situations during the winter. In Denmark, the system operator procures resources to maintain a satisfactory level of security of supply. In Norway the TSO has set up a Regulation Power Option Market (RKOM) to secure a satisfactory level of operational reserves at all times, also in winter with high load demand. Only the arrangements in Finland and Sweden fall under the heading of Peak Load Arrangements defined in Nordel Guidelines. NordREG has been invited by the Electricity Market Group (EMG) to evaluate Nordel's proposal for 'Guidelines for transitional Peak Load Arrangements'. The EMG has also financed a study made by EC Group to support NordREG in the evaluation of the proposal. The study has been taken into account in NordREG's evaluation. In parallel to the EMG task, the Swedish regulator, the Energy Markets Inspectorate, has been given the task by the Swedish government to investigate a long term solution of the peak load issue. The Swedish and Finnish TSOs have together with Nord Pool Spot worked on finding a harmonized solution for activation of the peak load reserves in the market. An agreement accepted by the relevant authorities was reached in early January 2009, and the arrangement has been implemented since 19th January 2009. NordREG views that the proposed Nordel guidelines have served as a starting point for the presently agreed procedure. However, NordREG does not see any need to further develop the Nordel guidelines for peak load arrangements. NordREG agrees with Nordel that the market should be designed to solve peak load problems through proper incentives to market players. NordREG presumes that the relevant authorities in each country will take decisions on the need for any peak load arrangement to ensure security of supply. NordREG proposes that such decisions should be

  6. Living arrangements and mental health in Finland

    Science.gov (United States)

    Joutsenniemi, Kaisla; Martelin, Tuija; Martikainen, Pekka; Pirkola, Sami; Koskinen, Seppo

    2006-01-01

    Background Non‐married persons are known to have poor mental health compared with married persons. Health differences between marital status groups may largely arise from corresponding differences in interpersonal social bonds. However, official marital status mirrors the social reality of persons to a decreasing extent, and living arrangements may be a better measure of social bonds. Little is known about mental health in different living arrangement groups. This study aims to establish the extent and determinants of mental health differences by living arrangement in terms of psychological distress (GHQ) and DSM‐IV psychiatric disorders (CIDI). Methods Data were used from the nationally representative cross sectional health 2000 survey, conducted in 2000–1 in Finland. Altogether 4685 participants (80%) aged 30–64 years were included in these analyses; comprehensive information was available on measures of mental health and living arrangements. Living arrangements were measured as follows: married, cohabiting, living with other(s) than a partner, and living alone. Results Compared with the married, persons living alone and those living with other(s) than a partner were approximately twice as likely to have anxiety or depressive disorders. Cohabiters did not differ from the married. In men, psychological distress was similarly associated with living arrangements. Unemployment, lack of social support, and alcohol consumption attenuated the excess psychological distress and psychiatric morbidity of persons living alone and of those living with other(s) than a partner by about 10%–50% each. Conclusions Living arrangements are strongly associated with mental health, particularly among men. Information on living arrangements, social support, unemployment, and alcohol use may facilitate early stage recognition of poor mental health in primary health care. PMID:16698975

  7. People management implications of virtual workplace arrangements

    OpenAIRE

    K. Ortlepp; X. Hloma

    2006-01-01

    Purpose: The purpose of this paper is to investigate the factors that led to an organisation implementing a particular form of virtual workplace arrangement, namely, home-based work. The benefits and disadvantages associated with this form of work arrangement are explored from both the managers' and home-based employees' perspectives. Design/Methodology/Approach: Given the exploratory nature of the empirical study on which this paper is based, a qualitative research design was adopt...

  8. Effect of long time service exposure on microstructure and mechanical properties of gas turbine vanes made of IN939 alloy

    International Nuclear Information System (INIS)

    Jahangiri, M.R.; Abedini, M.

    2014-01-01

    Highlights: • Microstructure of service-exposed turbine vanes made of IN939 was investigated. • Mechanical properties of service-exposed alloy were also investigated. • Formation of M 23 C 6 films on GBs and degeneration of MCs are microstructural changes. • Despite its thermodynamic favorability, σ phase is not observed in microstructure. • Microstructural changes lead to a loss in tensile ductility and creep life. - Abstract: In the present study, the effects of long-term service exposure have been investigated on microstructure and mechanical properties of gas turbine vanes made of IN939 superalloy. The major microstructural changes for the investigated service-exposed vanes include the formation of continuous grain boundary carbides and the transformation (degeneration) of MC carbides located at the grain boundaries. The brittle σ phase, which is predicted to be stable on the basis of thermodynamic calculations, is not observed in the microstructure of service-exposed vanes. The microstructural changes during service lead to a loss in room temperature ductility as well as in creep properties of the alloy

  9. Performance Enhancement of the In-Line Fan Equipped with the Guiding Vane and the Tail Body

    Directory of Open Access Journals (Sweden)

    Hung-Cheng Yen

    2014-02-01

    Full Text Available This integrated numerical and experimental study intends to enhance the performance of an in-line fan with the implement of the guiding vane and the tail body. At first the flow flied associated with the original in-line fan is simulated and analyzed within the framework of CFD code Fluent, in which the finite volume method is applied. Next, the guiding vane is constructed based on the calculated flow characteristics, and attached in the downstream of rotor to smoothen the flow pattern. An appropriate guiding vane with high-performance and low-noise features can be achieved after several design iterations. In addition, the tail body connected to the motor is introduced for further enhancing the fan performance by reducing the sizes of wake and reversed flow behind the hub. Thereafter, to manufacture the mockup for experimental verification, the modified fan with guiding vane is plotted in the CAD/CAM format for mockup fabrication via the rapid-prototype technique. Moreover, a set of relations correlating the performance and noise of this fan prototype are executed inside AMCA test chamber and semianechoic chamber, respectively. Consequently, the feasibility of design scheme and numerical system can be verified according to these experimental results. In summary, this work provides a systematic scheme for designing and analyzing the in-line fan.

  10. Numerical study of pressure fluctuations in different guide vanes' opening angle in pump mode of a pump turbine

    International Nuclear Information System (INIS)

    Sun, Y K; Zuo, Z G; Liu, S H; Wu, Y L; Liu, J T

    2012-01-01

    A numerical model based on a pumped storage power station was built to develop the numerical simulation, to analyze the pressure fluctuations in a pump turbine in different guide vanes' opening angle. The different guide vanes' opening angles were simulated using the SST k-ω turbulence model and SIMPLEC Pressure-Velocity coupling scheme. The pressure sensor were placed in mainly three positions, they are: bottom ring between runner and the wicket gates, downstream and left side in the draft tube cone below the runner. All the peak to peak values of pressure fluctuation meet signal probability of 97%. The frequency is gained by Fast Fourier Transform. The pressure fluctuations in different positions of the model in pump condition were showed when the guide vanes' opening angels were different. The simulation results confirmed the results gained in model tests. The results show that pressure fluctuations in design opening angle were much lower than those in off design opening angle. The main source of pressure fluctuations between runner and guide vanes is rotor stator interaction. While a lower frequency is the main frequency of the pressure fluctuation in draft tube.

  11. Preliminary Investigation on Turbulent Flow in Tight-lattice Rod Bundle with Twist-mixing Vane Spacer Grid

    International Nuclear Information System (INIS)

    Lee, Chiyoung; Kwack, Youngkyun; Park, Juyong; Shin, Changhwan; In, Wangkee

    2013-01-01

    Our research group has investigated the effect of P/D difference on the behavior of turbulent rod bundle flow without the mixing vane spacer grid, using PIV (Particle Image Velocimetry) and MIR (Matching Index of Refraction) techniques for tight lattice fuel rod bundle application. In this work, using the tight-lattice rod bundle with a twist-mixing vane spacer grid, the turbulent rod bundle flow is preliminarily examined to validate the PIV measurement and CFD (Computational Fluid Dynamics) simulation. The turbulent flow in the tight-lattice rod bundle with a twist-mixing vane spacer grid was preliminarily examined to validate the PIV measurement and CFD simulation. Both were in agreement with each other within a reasonable degree of accuracy. Using PIV measurement and CFD simulation tested in this work, the detailed investigations on the behavior of turbulent rod bundle flow with the twist-mixing vane spacer grid will be performed at various conditions, and reported in the near future

  12. 2.5 MeV CW 4-vane RFQ accelerator design for BNCT applications

    Science.gov (United States)

    Zhu, Xiaowen; Wang, Hu; Lu, Yuanrong; Wang, Zhi; Zhu, Kun; Zou, Yubin; Guo, Zhiyu

    2018-03-01

    Boron Neutron Capture Therapy (BNCT) promises a bright future in cancer therapy for its highly selective destruction of cancer cells, using the 10B +n→7Li +4 He reaction. It offers a more satisfactory therapeutic effect than traditional methods for the treatment of malignant brain tumors, head and neck cancer, melanoma, liver cancer and so on. A CW 4-vane RFQ, operating at 162.5 MHz, provides acceleration of a 20 mA proton beam to 2.5 MeV, bombarding a liquid lithium target for neutron production with a soft neutron energy spectrum. The fast neutron yield is about 1.73×1013 n/s. We preliminarily develop and optimize a beam shaping assembly design for the 7Li(p, n)7Be reaction with a 2.5 MeV proton beam. The epithermal neutron flux simulated at the beam port will reach up to 1 . 575 ×109 n/s/cm2. The beam dynamics design, simulation and benchmark for 2.5 MeV BNCT RFQ have been performed with both ParmteqM (V3.05) and Toutatis, with a transmission efficiency higher than 99.6% at 20 mA. To ease the thermal management in the CW RFQ operation, we adopt a modest inter-vane voltage design (U = 65 kV), though this does increase the accelerator length (reaching 5.2 m). Using the well-developed 3D electromagnetic codes, CST MWS and ANSYS HFSS, we are able to deal with the complexity of the BNCT RFQ, taking the contribution of each component in the RF volume into consideration. This allows us to optimize the longitudinal field distribution in a full-length model. Also, the parametric modeling technique is of great benefit to extensive modifications and simulations. In addition, the resonant frequency tuning of this RFQ is studied, giving the tuning sensitivities of vane channel and wall channel as -16.3 kHz/°C and 12.4 kHz/°C, respectively. Finally, both the multipacting level of this RFQ and multipacting suppressing in the coaxial coupler are investigated.

  13. Investigating the thermal hydraulic performance of spacer grid with mixing vanes using STAR-CCM+ and MATRA

    International Nuclear Information System (INIS)

    Agbodemegbe, V. Y.

    2014-07-01

    Enhancement of heat transfer for flow through rod bundles is linked to the extent and sustainability of mixing in the flow geometry. Spacer grids used as support for rod bundles in nuclear reactors, when attached with ditferent designs of mixing vanes promote turbulent mixing by inducing swirl or forced lateral convection that improves mixing within or between sub-channels. The improved turbulent mixing raises the margin of the onset of critical heat flux in light water reactors (LWR) and also ensures a higher fuel cycle economy. To optimize design of mixing vanes and performance of spacer grids with mixing vanes, computational fluid dynamic simulations arc carried out on new designs and validated experimentally prior to industrial application. In the present study, computational fluid dynamic simulation using STAR-CCM+ and sub-channel analysis with MATRA were performed for flow of water through a 5 X 5 rod bundle geometry for which the rod to rod pitch to diameter ratio was 1.33 and the wall to rod pitch to diameter ratio was 0.74. The two layer k-epsilon turbulence model with an all- y + automatic wall treatment function in STAR-CCM+ were adopted for an isothermal single phase flow through the geometry with imposed cyclic periodic and non-cyclic periodic interface boundary conditions. The objective was to primarily investigate the detail flow behavior in rod bundle in the presence of spacer grids with and without attached mixing vanes. Furthermore, the present study also investigated the extent of turbulent mixing and lateral mass flux induced by the mixing vanes through comparative analysis of parametric trends for spacer grid with and without mixing vanes. New models and empirical correlations for describing the mixing vanes effects were also developed. These semi-empirical correlations improved the prediction for lateral mass flux due to turbulence, fraction of flow diverted through gaps and cross-flow resistance coefficients. Validation of simulation results

  14. On the Relativistic Correction of Particles Trajectory in Tandem Type Electrostatic Accelerator

    Science.gov (United States)

    Minárik, Stanislav

    2015-08-01

    A constant potential is applied to the acceleration of the ion-beam in the tandem type electrostatic accelerator. However, not just one voltage is applied, but instead a number of applications can be made in succession by means of the tandem arrangement of high voltage tubes. This number of voltage applications, which is the number of so-called "stages" of a tandem accelerator, may be two, three, or four, depending on the chosen design. Electrostatic field with approximately constant intensity acts on ions in any stage. In general, non-relativistic dynamics is used for the description of the ion transport in tandem accelerator. Energies of accelerated ions are too low and relativistic effects cannot be commonly observed by standard experimental technique. Estimation of possible relativistic correction of ion trajectories is therefore only a matter of calculation. In this note, we briefly present such calculation. Our aim is to show how using the relativistic dynamics modifies the particles trajectory in tandem type accelerator and what parameters determine this modification.

  15. Transonic Axial Splittered Rotor Tandem Stator Stage

    Science.gov (United States)

    2016-12-01

    Wennerstrom [3] admits, “It might be possible to do a credible job of optimizing splitter-vane geometry analytically by one of the time- dependent or...section were saved as a .stl file. This file was transferred to the Repetier software and printer configuration preferences were entered. A detailed...Exponent 2.0000e+00 Reference Volume Mean Control Volume Reference Pressure 1.0000e+00 [atm] Heat Transfer Model Total Energy Include Viscous

  16. Application of dynamic slip wall modeling to a turbine nozzle guide vane

    Science.gov (United States)

    Bose, Sanjeeb; Talnikar, Chaitanya; Blonigan, Patrick; Wang, Qiqi

    2015-11-01

    Resolution of near-wall turbulent structures is computational prohibitive necessitating the need for wall-modeled large-eddy simulation approaches. Standard wall models are often based on assumptions of equilibrium boundary layers, which do not necessarily account for the dissimilarity of the momentum and thermal boundary layers. We investigate the use of the dynamic slip wall boundary condition (Bose and Moin, 2014) for the prediction of surface heat transfer on a turbine nozzle guide vane (Arts and de Rouvroit, 1992). The heat transfer coefficient is well predicted by the slip wall model, including capturing the transition to turbulence. The sensitivity of the heat transfer coefficient to the incident turbulence intensity will additionally be discussed. Lastly, the behavior of the thermal and momentum slip lengths will be contrasted between regions where the strong Reynolds analogy is invalid (near transition on the suction side) and an isothermal, zero pressure gradient flat plate boundary layer (Wu and Moin, 2010).

  17. Lateral Flow Field Behavior Downstream of Mixing Vanes In a Simulated Nuclear Fuel Rod Bundle

    International Nuclear Information System (INIS)

    Conner, Michael E.; Smith, L. David III; Holloway, Mary V.; Beasley, Donald E.

    2004-01-01

    To assess the fuel assembly performance of PWR nuclear fuel assemblies, average subchannel flow values are used in design analyses. However, for this highly complex flow, it is known that local conditions around fuel rods vary dependent upon the location of the fuel rod in the fuel assembly and upon the support grid design that maintains the fuel rod pitch. To investigate the local flow in a simulated nuclear fuel rod bundle, a testing technique has been employed to measure the lateral flow field in a 5 x 5 rod bundle. Particle Image Velocimetry was used to measure the lateral flow field downstream of a support grid with mixing vanes for four unique subchannels in the 5 x 5 bundle. The dominant lateral flow structures for each subchannel are compared in this paper including the decay of these flow structures. (authors)

  18. Tubular-Type Hydroturbine Performance for Variable Guide Vane Opening by CFD

    Science.gov (United States)

    Kim, Y. T.; Nam, S. H.; Cho, Y. J.; Hwang, Y. C.; Choi, Y. D.; Nam, C. D.; Lee, Y. H.

    Micro hydraulic power generation which has output of less or equal to 100kW is attracting considerable attention. This is because of its small, simple, renewable, and large amount of energy resources. By using a small hydro power generator of which main concept is based on using differential water pressures in pipe lines, energy which was initially wasted by use of a reducing valve at an end of the pipeline, is collected by a turbine in the hydro power generator. A propeller shaped hydroturbine has been used in order to make use of this renewable pressure energy. In this study, in order to acquire basic design data of tubular type hydroturbine, output power, head, and efficiency characteristics due to the guide vane opening angle are examined in detail. Moreover, influences of pressure, tangential and axial velocity distributions on turbine performance are investigated by using a commercial CFD code.

  19. Active Flow Control in a Radial Vaned Diffuser for Surge Margin Improvement: A Multislot Suction Strategy

    Directory of Open Access Journals (Sweden)

    Aurélien Marsan

    2017-01-01

    Full Text Available This work is the final step of a research project that aims at evaluating the possibility of delaying the surge of a centrifugal compressor stage using a boundary-layer suction technique. It is based on Reynolds-Averaged Navier-Stokes numerical simulations. Boundary-layer suction is applied within the radial vaned diffuser. Previous work has shown the necessity to take into account the unsteady behavior of the flow when designing the active flow control technique. In this paper, a multislot strategy is designed according to the characteristics of the unsteady pressure field. Its implementation results in a significant increase of the stable operating range predicted by the unsteady RANS numerical model. A hub-corner separation still exists further downstream in the diffuser passage but does not compromise the stability of the compressor stage.

  20. Scaling laws for gas–liquid flow in swirl vane separators

    International Nuclear Information System (INIS)

    Liu, Li; Bai, Bofeng

    2016-01-01

    Highlights: • Model for swirl vane separator performance is established with similarity criteria. • Scaling laws are developed to correlate downscale test with prototype separator. • Effects of key similarity criteria on separation performance are studied. • The vital role of droplet size distribution on separation performance is discussed. - Abstract: Laboratory tests on gas–liquid flow in swirl vane separators are usually carried out to help establish an experimental database for separator design and performance improvement. Such model tests are generally performed in the reduced scale and not on the actual working conditions. Though great efficiency is often obtainable in the reduced model, the performance of the full-sized prototype usually cannot be well predicted. To design downscale model tests and apply the experimental results to predict the prototype, a general relationship to correlate them is required. In this paper, the relation of the similitude-criterion concerning the pressure loss is presented by using the dimensionless analysis, and mathematical models for critical droplet diameter, grade efficiency and overall separation efficiency are established by analyzing the features of the droplet trajectory in gas swirling flow field. The essential similarity criteria accounting for pressure loss and separation efficiency are obtained, respectively. On this basis, the scaling laws which enable a comparison between the reduced model and the full-sized prototype under similar conditions are also developed. It is found that the overall separation efficiency is significantly affected by the size distribution of the small droplets, especially when the mean diameter is smaller than the critical droplet diameter.

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

    Science.gov (United States)

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

    2016-03-01

    A vane pump-grinder system was extended to enable the manufacture of finely dispersed emulsion-type sausages by constructing and attaching a high-shear homogenizer at the outlet. We hypothesized that the dispersing capabilities of the extended system may be improved to the point of facilitating meat-fat emulsification due to an overall increased volumetric energy input EV . Coarsely ground raw material mixtures were processed to yield meat batters at varying volume flow rates (10 to 60 L/min) and rotational rotor speeds of the homogenizer nrotor (1000 to 3400 rpm). The normalized torques acting on pump, grinder, and homogenizer motors were recorded and unit power consumptions were calculated. The structure of the manufactured meat batters and sausages were analyzed via image analysis. Key physicochemical properties of unheated and heated batters, that is, texture, water-binding, color, and solubilized protein were determined. The mean diameter d10 of the visible lean meat particles varied between 352 and 406 μm whereas the mean volume-surface diameter d32 varied between 603 and 796 μm. The lightness L* ranged from 66.2 to 70.7 and correlated with the volumetric energy input and product structure. By contrast, varying process parameters did not impact color values a* (approximately 11) and b* (approximately 8). Interestingly, water-binding and protein solubilization were not affected. An exponential process-structure relationship was identified allowing manufacturers to predict product properties as a function of applied process parameters. Raw material mixtures can be continuously comminuted, emulsified, and subsequently filled into casings using an extended vane pump-grinder. © 2016 Institute of Food Technologists®

  2. 5S rRNA gene arrangements in protists: a case of nonadaptive evolution.

    Science.gov (United States)

    Drouin, Guy; Tsang, Corey

    2012-06-01

    Given their high copy number and high level of expression, one might expect that both the sequence and organization of eukaryotic ribosomal RNA genes would be conserved during evolution. Although the organization of 18S, 5.8S and 28S ribosomal RNA genes is indeed relatively well conserved, that of 5S rRNA genes is much more variable. Here, we review the different types of 5S rRNA gene arrangements which have been observed in protists. This includes linkages to the other ribosomal RNA genes as well as linkages to ubiquitin, splice-leader, snRNA and tRNA genes. Mapping these linkages to independently derived phylogenies shows that these diverse linkages have repeatedly been gained and lost during evolution. This argues against such linkages being the primitive condition not only in protists but also in other eukaryote species. Because the only characteristic the diverse genes with which 5S rRNA genes are found linked with is that they are tandemly repeated, these arrangements are unlikely to provide any selective advantage. Rather, the observed high variability in 5S rRNA genes arrangements is likely the result of the fact that 5S rRNA genes contain internal promoters, that these genes are often transposed by diverse recombination mechanisms and that these new gene arrangements are rapidly homogenized by unequal crossingovers and/or by gene conversions events in species with short generation times and frequent founder events.

  3. Meiotic transmission of Drosophila pseudoobscura chromosomal arrangements.

    Directory of Open Access Journals (Sweden)

    Richard P Meisel

    Full Text Available Drosophila pseudoobscura harbors a rich gene arrangement polymorphism on the third chromosome generated by a series of overlapping paracentric inversions. The arrangements suppress recombination in heterokaryotypic individuals, which allows for the selective maintenance of coadapted gene complexes. Previous mapping experiments used to determine the degree to which recombination is suppressed in gene arrangement heterozygotes produced non-recombinant progeny in non-Mendelian ratios. The deviations from Mendelian expectations could be the result of viability differences between wild and mutant chromosomes, meiotic drive because of achiasmate pairing of homologues in heterokaryotypic females during meiosis, or a combination of both mechanisms. The possibility that the frequencies of the chromosomal arrangements in natural populations are affected by mechanisms other than adaptive selection led us to consider these hypotheses. We performed reciprocal crosses involving both heterozygous males and females to determine if the frequency of the non-recombinant progeny deviates significantly from Mendelian expectations and if the frequencies deviate between reciprocal crosses. We failed to observe non-Mendelian ratios in multiple crosses, and the frequency of the non-recombinant classes differed in only one of five pairs of reciprocal crosses despite sufficient power to detect these differences in all crosses. Our results indicate that deviations from Mendelian expectations in recombination experiments involving the D. pseudoobscura inversion system are most likely due to fitness differences of gene arrangement karyotypes in different environments.

  4. Tandem mirror technology demonstration facility

    Energy Technology Data Exchange (ETDEWEB)

    1983-10-01

    This report describes a facility for generating engineering data on the nuclear technologies needed to build an engineering test reactor (ETR). The facility, based on a tandem mirror operating in the Kelley mode, could be used to produce a high neutron flux (1.4 MW/M/sup 2/) on an 8-m/sup 2/ test area for testing fusion blankets. Runs of more than 100 h, with an average availability of 30%, would produce a fluence of 5 mW/yr/m/sup 2/ and give the necessary experience for successful operation of an ETR.

  5. Tandem mirror technology demonstration facility

    International Nuclear Information System (INIS)

    1983-10-01

    This report describes a facility for generating engineering data on the nuclear technologies needed to build an engineering test reactor (ETR). The facility, based on a tandem mirror operating in the Kelley mode, could be used to produce a high neutron flux (1.4 MW/M 2 ) on an 8-m 2 test area for testing fusion blankets. Runs of more than 100 h, with an average availability of 30%, would produce a fluence of 5 mW/yr/m 2 and give the necessary experience for successful operation of an ETR

  6. Gas box control system for Tandem Mirror Experiment-Upgrade

    International Nuclear Information System (INIS)

    Bell, H.H. Jr.; Hunt, A.L.; Clower, C.A. Jr.

    1983-01-01

    The Tandem Mirror Experiment-Upgrade (TMX-U) uses several methods to feed gas (usually deuterium) at different energies into the plasma region of the machine. One is an arrangement of eight high-speed piezo-electric valves mounted on special manifolds (gas box) that feed cold gas directly to the plasma. This paper describes the electronic valve control and data acquisition portions of the gas box, which are controlled by a desk-top computer. Various flow profiles have been developed and stored in the control computer for ready access by the operator. The system uses two modes of operation, one that exercises and characterizes the valves and one that operates the valves with the rest of the experiment. Both the valve control signals and the pressure transducers data are recorded on the diagnostics computer so that they are available for experiment analysis

  7. Arrangement for formation perforating and fracturing

    Energy Technology Data Exchange (ETDEWEB)

    Belyaev, B M; Vitsenii, E M; Zheltov, Yu P; Nikolaev, S I

    1962-03-06

    An arrangement for perforating and hydraulic fracturing, to be lowered on a wire line, consists of a chamber with a shaped charge, a head and a nozzle. This arrangement enables carrying out, simultaneously, the operations of perforating and fracturing. The device may be equipped with separate sections with shaped charges and a powder chamber in which powder charges are placed, designed to be ignited in sequence by slow- acting electric igniters. For controlling the gas pressure and strengthening the arrangement in the zone of perforation, the device is equipped with rubber seals which release the ring elements under pressure of explosive gas. Between the walls of the casing and the rubber seals is an annular space through the gas escapes.

  8. Exchange rate regimes and monetary arrangements

    Directory of Open Access Journals (Sweden)

    Ivan Ribnikar

    2005-06-01

    Full Text Available There is a close relationship between a country’s exchange rate regime and monetary arrangement and if we are to examine monetary arrangements then exchange rate regimes must first be analysed. Within the conventional and most widely used classification of exchange rate regimes into rigid and flexible or into polar regimes (hard peg and float on one side, and intermediate regimes on the other there, is a much greater variety among intermediate regimes. A more precise and, as will be seen, more useful classification of exchange rate regimes is the first topic of the paper. The second topic is how exchange rate regimes influence or determine monetary arrangements and monetary policy or monetary policy regimes: monetary autonomy versus monetary nonautonomy and discretion in monetary policy versus commitment in monetary policy. Both topics are important for countries on their path to the EU and the euro area

  9. People management implications of virtual workplace arrangements

    Directory of Open Access Journals (Sweden)

    K. Ortlepp

    2006-12-01

    Full Text Available Purpose: The purpose of this paper is to investigate the factors that led to an organisation implementing a particular form of virtual workplace arrangement, namely, home-based work. The benefits and disadvantages associated with this form of work arrangement are explored from both the managers' and home-based employees' perspectives. Design/Methodology/Approach: Given the exploratory nature of the empirical study on which this paper is based, a qualitative research design was adopted so as to ensure that the data collection process was dynamic and probing in nature. Semi-structured in-depth interviews were therefore used as instruments for data collection. Findings: The research findings indicate that virtual work arrangements such as home-based work arrangements have advantages for both employers and employees. For instance, reduction of costs associated with office space and facilities, decrease in absenteeism rates, increased employee job satisfaction and improvements in employees' general quality of life. However, a number of negative experiences related to this form of virtual work arrangement are also evident, for example, feelings of isolation as well as stress related to the inability to have firm boundaries between work and family responsibilities. Implications: Based on the insights gained from the findings in the empirical study, a number of areas that need to be given specific attention when organisations are introducing virtual workplace arrangements of this nature are identified. Recommendations made in this article are important for human resource management specialists as well as core business policy makers considering different forms of organisational design. Originality/Value: Maximising the quality of production and service provided has become the prime objective in most organisations in the 21st century. Technology has made it possible for some jobs to be performed at any place at any time and has facilitated the

  10. Injector of the Utrecht EN tandem

    Energy Technology Data Exchange (ETDEWEB)

    Borg, K. van der; Haas, A.P. de; Hoogenboom, A.M.; Strasters, B.A.; Vermeer, A.; Zwol, N.A. van (Rijksuniversiteit Utrecht (Netherlands). Fysisch Lab.)

    1984-02-15

    An injector has been built to obtain improved beam transmission through the EN tandem. The injector has been provided with a 90/sup 0/ analysing magnet, m/..delta..m=300, and 130 kV preacceleration. Beam optics calculations have been made for the injector and tandem. The injector has been equipped with a fiber optics control and data acquisition system.

  11. The injector of the Utrecht EN tandem

    International Nuclear Information System (INIS)

    Borg, K. van der; Haas, A.P. de; Hoogenboom, A.M.; Strasters, B.A.; Vermeer, A.; Zwol, N.A. van

    1984-01-01

    An injector has been built to obtain improved beam transmission through the EN tandem. The injector has been provided with a 90 0 analysing magnet, m/Δm=300, and 130 kV preacceleration. Beam optics calculations have been made for the injector and tandem. The injector has been equipped with a fiber optics control and data acquisition system. (orig.)

  12. The Kyoto University tandem upgrading project

    International Nuclear Information System (INIS)

    Nakamura, Masanobu; Shimoura, Susumu; Takimoto, Kiyohiko; Sakaguchi, Harutaka; Kobayashi, Shinsaku

    1988-01-01

    A brief description on the Kyoto University tandem upgrading project. The project consists of replacing the old 5 MV tandem Van de Graaff by an 8UDH pelletron. The old pressure vessel and beam lines are used again without significant modification. The project is planned to be completed at the end of 1989. (orig.)

  13. Parametric studies of tandem mirror reactors

    International Nuclear Information System (INIS)

    Carlson, G.A.; Boghosian, B.M.; Fink, J.H.; Myall, J.O.; Neef, W.S. Jr.

    1979-01-01

    This report, along with its companion, An Improved Tandem Mirror Reactor, discusses the recent progress and present status of our tandem mirror reactor studies. This report presents the detailed results of parametric studies up to, but not including, the very new ideas involving thermal barriers

  14. Packet models revisited: tandem and priority systems

    NARCIS (Netherlands)

    M.R.H. Mandjes (Michel)

    2004-01-01

    textabstractWe examine two extensions of traditional single-node packet-scale queueing models: tandem networks and (strict) priority systems. Two generic input processes are considered: periodic and Poisson arrivals. For the two-node tandem, an exact expression is derived for the joint distribution

  15. Tandem Translation Classroom: A Case Study

    Science.gov (United States)

    Kim, Dohun; Koh, Taejin

    2018-01-01

    The transition to student-centred learning, advances in teleconferencing tools, and active international student exchange programmes have stimulated tandem learning in many parts of the world. This pedagogical model is based on a mutual language exchange between tandem partners, where each student is a native speaker in the language the…

  16. Device operation of organic tandem solar cells

    NARCIS (Netherlands)

    Hadipour, A.; de Boer, B.; Blom, P. W. M.

    2008-01-01

    A generalized methodology is developed to obtain the current-voltage characteristic of polymer tandem solar cells by knowing the electrical performance of both sub cells. We demonstrate that the electrical characteristics of polymer tandem solar cells are correctly predicted for both the series and

  17. Military Technology and Conventional Weapons Export Controls: The Wassenaar Arrangement

    National Research Council Canada - National Science Library

    Grimmett, Richard F

    2006-01-01

    This report provides background on the Wassenaar Arrangement, which was formally established in July 1996 as a multilateral arrangement aimed at controlling exports of conventional weapons and related...

  18. Numerical investigation of variable inlet guide vanes with trailing-edge dual slots to decrease the aerodynamic load on centrifugal compressor impeller

    Directory of Open Access Journals (Sweden)

    Jianchi Xin

    2016-03-01

    Full Text Available In engineering practice, most centrifugal compressors use variable inlet guide vanes which can provide pre-whirl and control volume flow rates. As the impeller of a centrifugal compressor passes through the wakes created from the guide vanes, the aerodynamic parameters change significantly. The concept of adding dual slots at the trailing-edge of the guide vanes is proposed for reducing the aerodynamic load on the compressor impeller blades. In this article, the steady and unsteady performances of the new guide vanes are analysed under two compressor operating conditions (winter and design conditions. The results show that the average amplitude of the impeller passing frequency at the leading edge has a 13% decrease under the winter condition, especially at the middle and root parts. Moreover, the dual slots structure has no effect on the overall compressor performance.

  19. Canister arrangement for storing radioactive waste

    Science.gov (United States)

    Lorenzo, D.K.; Van Cleve, J.E. Jr.

    1980-04-23

    The subject invention relates to a canister arrangement for jointly storing high level radioactive chemical waste and metallic waste resulting from the reprocessing of nuclear reactor fuel elements. A cylindrical steel canister is provided with an elongated centrally disposed billet of the metallic waste and the chemical waste in vitreous form is disposed in the annulus surrounding the billet.

  20. Circuit arrangement for indicating radiation dose rates

    International Nuclear Information System (INIS)

    Virag, Ernoe; Nyari, Istvan; Simon, Jozsef; Styevko, Mihaly; Krampe, Geza.

    1981-01-01

    The invention presents a dosemeter electronic circuit arrangement indicating hazardous dose rate threshold. If the treshold is reached or exceeded, well distinguished sound and light alarm is turned on immidiately. Moreover, certain critical levels can also be indicated by making the intermittent singalling continuous. (A.L.)

  1. 45 CFR 63.4 - Cooperative arrangements.

    Science.gov (United States)

    2010-10-01

    ... another State, to apply for assistance. (b) A joint application made by two or more applicants for... activities performed by each of the joint applicants or may have a combined budget. If joint applications... authorizing separate amounts for each of the joint applicants. (c) In the case of each cooperative arrangement...

  2. Metacognitive Scaffolding in an Innovative Learning Arrangement

    Science.gov (United States)

    Molenaar, Inge; van Boxtel, Carla A. M.; Sleegers, Peter J. C.

    2011-01-01

    This study examined the effects of metacognitive scaffolds on learning outcomes of collaborating students in an innovative learning arrangement. The triads were supported by computerized scaffolds, which were dynamically integrated into the learning process and took a structuring or problematizing form. In an experimental design the two…

  3. 15 CFR 743.1 - Wassenaar Arrangement.

    Science.gov (United States)

    2010-01-01

    ... 15 Commerce and Foreign Trade 2 2010-01-01 2010-01-01 false Wassenaar Arrangement. 743.1 Section 743.1 Commerce and Foreign Trade Regulations Relating to Commerce and Foreign Trade (Continued) BUREAU... following: a. 30 elements or less; or b. Incorporating time delay-and-integration within the element and...

  4. Arrangement of Renal Arteries in Guinea Pig.

    Science.gov (United States)

    Mazensky, David; Flesarova, Slavka

    2017-03-01

    The aim of this study was to describe origin, localization, and variations of renal arteries in guinea pig. The study was carried out on 26 adult guinea pigs. We prepared corrosion casts of the guinea pig arterial system. Batson's corrosion casting kit no. 17 was used as the casting medium. In 57.7% of specimens, a. renalis dextra was present as a single vessel with different level of its origin from aorta abdominalis. In 38.5% of specimens, two aa. renales dextrae were present with variable origin and arrangement. The presence of three aa. renales dextrae we found in one specimen. In 76.9% of specimens, a. renalis sinistra was present as a single vessel with different level of its origin from aorta abdominalis and variable arrangement. In 23.1% of specimens, we found two aa. renales sinistrae with variable origin and arrangement. The anatomical knowledge of the renal arteries, and its variations are of extreme importance for the surgeon that approaches the retroperitoneal region in several experiments, results of which are extrapolated in human. This is the first work dealing with the description of renal arteries arrangement in guinea pig. Anat Rec, 300:556-559, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  5. 75 FR 346 - Proposed Subsequent Arrangement

    Science.gov (United States)

    2010-01-05

    ... Uses of Nuclear Energy. This subsequent arrangement concerns the retransfer of 28,409 kg of U.S.-origin... Fuels in Kanakawa-ken, Japan. The material, which is currently located at Cameco, Port Hope, Ontario, will be transferred to Global Nuclear Fuel, Kanakawa-ken, Japan to be fabricated into fuel pellets and...

  6. 77 FR 35366 - Proposed Subsequent Arrangement

    Science.gov (United States)

    2012-06-13

    ... arrangement concerns the retransfer of 6,672,212 g of U.S.-origin enriched uranium fuel fabrications scrap, containing 233,977 g of the isotope U-235 (less than five percent enrichment), from Nuclear Fuel Industries... material, which is currently located at Nuclear Fuels Industries, Ltd. in Japan, will be transferred to...

  7. 78 FR 72072 - Proposed Subsequent Arrangement

    Science.gov (United States)

    2013-12-02

    ... g of U.S.-origin atomized low-enriched uranium-7wt. % molybdenum powder, containing 365.638 g in the..., which is located at and was prepared by KAERI, will be used for the irradiation test of full-size fuel... subsequent arrangement concerning the retransfer of nuclear material of United States origin will not be...

  8. 75 FR 82005 - Proposed Subsequent Arrangement

    Science.gov (United States)

    2010-12-29

    ... arrangement concerns the retransfer of 29,887 kg of U.S.-origin natural uranium dioxide (88.00% U), 26,300 kg... Fuel Co. Ltd. in Yuson-Gu, Taejon, South Korea. The material, which is currently located at Cameco, will be transferred for fuel fabrication by Korea Nuclear Fuel Co. Ltd for final use in a civilian...

  9. Enhancing sediment distribution at the vicinity of power plant intakes using double rows of vanes and groins (Case study: New tebbin power plant

    Directory of Open Access Journals (Sweden)

    Sayed Mahgoub

    2013-12-01

    The study results showed that, in case of vanes absence, sediments with rates 1–2 m3/week were stuck within the sediment trap under the winter conditions. Also, the results indicated that the submerged vanes play an important role in preventing the sediment intrusion. Also, it was clear that using groins might lead to enhancing the sediment distribution at the intake vicinity.

  10. Advanced Instrumentation for Measuring Fluid-Structure Coupling Phenomena in the Guide Vanes Cascade of a Pump-Turbine Scale Model

    OpenAIRE

    Roth, Steven; Hasmatuchi, Vlad; Botero, Francisco; Farhat, Mohamed; Avellan, François

    2010-01-01

    In the present study, the fluid-structure coupling is investigated in the guide vanes of a pump-turbine scale model placed in one of the test rigs of the Laboratory for Hydraulic Machines (EPFL) in Lausanne. The paper focuses on the advanced instrumentation used to get reliable and complete fluid-structure coupling results. Semi-conductor strain gages are installed on three guide vanes which are especially weakened to account for stronger fluid-structure coupling phenomena. These are statical...

  11. Loss model for off-design performance analysis of radial turbines with pivoting-vane, variable-area stators

    Science.gov (United States)

    Meitner, P. L.; Glassman, A. J.

    1980-01-01

    An off-design performance loss model for a radial turbine with pivoting, variable-area stators is developed through a combination of analytical modeling and experimental data analysis. A viscous loss model is used for the variation in stator loss with setting angle, and stator vane end-clearance leakage effects are predicted by a clearance flow model. The variation of rotor loss coefficient with stator setting angle is obtained by means of an analytical matching of experimental data for a rotor that was tested with six stators, having throat areas from 20 to 144% of the design area. An incidence loss model is selected to obtain best agreement with experimental data. The stator vane end-clearance leakage model predicts increasing mass flow and decreasing efficiency as a result of end-clearances, with changes becoming significantly larger with decreasing stator area.

  12. Preliminary results for validation of Computational Fluid Dynamics for prediction of flow through a split vane spacer grid

    International Nuclear Information System (INIS)

    Rashkovan, A.; Novog, D.R.

    2012-01-01

    This paper presents the results of the CFD simulations of turbulent flow past spacer grid with mixing vanes. This study summarizes the first stage of the ongoing numerical blind exercise organized by OECD-NEA. McMaster University along with other participants plan to submit a numerical prediction of the detailed flow field and turbulence characteristics of the flow past 5x5 rod bundle with a spacer grid equipped with two types of mixing vanes. The results will be compared with blind experimental measurements performed in Korea. Due to the fact that a number of the modeling strategies are suggested in literature for such types of flows, we have performed a series of tests to assess the mesh requirements, flow steadiness, turbulence modeling and wall treatment effects. Results of these studies are reported in the present paper. (author)

  13. A new low threshold bi-directional wind vane and its potential impact on unplanned atmospheric release prediction

    International Nuclear Information System (INIS)

    Parker, M.J.

    1996-01-01

    At the Savannah River Site, the Environmental Transport Group (ETG) maintains and develops a comprehensive meteorological monitoring program which employs bi-directional wind vanes (bivanes) for the measurement of horizontal and vertical wind direction and turbulence. Wind data collected near and below instrument starting thresholds under stable nighttime conditions with these bivanes can result in artificially large standard deviations of horizontal wind direction (σA). In one hypothetical case, downwind concentrations could be underestimated by a factor of 40 by using artificially high σA data in a Gaussian dispersion model. In an effort to improve low wind speed measurements of wind direction, a Cooperative Research and Development Agreement (CRADA) between Met One Instruments and the Westinghouse Savannah River Company (WSRC) has been created to improve the dynamic performance of the Met One Model 1585 Bi-Directional Wind Vane

  14. Status of JAERI tandem accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Yoshida, Tadashi; Kanda, Susumu; Takeuchi, Suehiro [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment] (and others)

    2001-02-01

    JAERI Tandem Accelerator had been operated approximately 230 days in fiscal year of 1999. Meanwhile, we had three times of maintenance period with vent. Total operation-times were 5273 hours. We could not carry out the experiment using rare gas, due to malfunction of the RF power supply for the ECR ion source. The type of the RF power supply is peculiar and it is impossible to get spare parts for repair. We are now investigating the backup RF power supply. The power supply for the magnet became unstable due to degradation of insulation in the shunt resistance, which is used for feedback stabilization. Stability was recovered after cleaning. The acrylic resin shaft was cracked. This cracks have a potential for severe accidents. So far bearing of the shaft has no problem. The reason of cracks may be self-destruction by charge accumulation in the shaft. JAERI Tandem Accelerator is approximately 20 years old. There appear requirements on the higher ion currents for additional ion species. Therefore, authors are investigating cost effective improvement plans of RFQ (Radio Frequency Quadra-pole) and IH type accelerator based on KEK (High Energy Accelerator Research Organization) R and D. As a whole, maintenance services for the control system are increasing due to some changes of computer programs. There are some difficulties to keep skilled personnel for facilities operation. Authors are gradually increasing hired personnel with contract from 1993. However, loads for JAERI permanent staffs are still heavy. It takes much longer time to educate skilled persons especially for safety. (Y. Tanaka)

  15. Combining effect of optimized axial compressor variable guide vanes and bleed air on the thermodynamic performance of aircraft engine system

    International Nuclear Information System (INIS)

    Kim, Sangjo; Son, Changmin; Kim, Kuisoon

    2017-01-01

    Aim of this work is to provide evidence of the effectiveness of combined use of the variable guide vanes (VGVs) and bleed air on the thermodynamic performance of aircraft engine system. This paper performed the comparative study to evaluate the overall thermal performance of an aircraft engine with optimized VGVs and bleed air, separately or simultaneously. The low-bypass ratio turbofan engine has been modeled with a 0D/1D modeling approach. The genetic algorithm is employed to find the optimum schedule of VGVs and bleed air. There are four types of design variables: (1) the inlet guide vane (IGV) angle, (2) the IGV and 1st stator vane (SV) angles, (3) bleed air mass flow rate at the exit of the axial compressor, and (4) both type 2 and type 3. The optimization is conducted with surge margin constraints of more than 10% and 15% in the axial compressor. The results show that the additional use of the bleed air increases the efficiency of the compressors. Overall, the percentage reductions of the total fuel consumption for the engine with the IGV, 1st SV and bleed air schedule is 1.63% for 15% surge margin constraints when compared with the engine with the IGV schedule. - Highlights: • The effect of combined use of variable guide vanes and bleed air is evaluated. • The genetic algorithm is employed to find the optimum setting angle and bleed air. • A low bypass ratio mixed turbofan engine is analyzed for optimization. • Additional use of the bleed air shows improved overall performance of the engine.

  16. The impact of inlet angle and outlet angle of guide vane on pump in reversal based hydraulic turbine performance

    International Nuclear Information System (INIS)

    Shi, F X; Yang, J H; Wang, X H; Zhang, R H; Li, C E

    2012-01-01

    In this paper, in order to research the impact of inlet angle and outlet angle of guide vane on hydraulic turbine performance, a centrifugal pump in reversal is adopted as turbine. A numerical simulation method is adopted for researching outer performance and flow field of turbine. The results show: inlet angle has a crucial role to turbine, to the same flow, there is a noticeable decline for the efficiency and head of turbine with the inlet angle increases. At the best efficiency point(EFP),to a same inlet angle, when the inlet angle greater than inlet angle, velocity circulation in guide vane outlet decreases, which lead the efficiency of turbine to reduce, Contrarily, the efficiency rises. With the increase of inlet angle and outlet angle, the EFP moves to the big flow area and the uniformity of pressure distribution becomes worse. The paper indicates that the inlet angle and outlet angle have great impact on the turbine performance, and the best combination exists for the inlet angle and outlet angle of the guide vane.

  17. 46 CFR 180.150 - Survival craft embarkation arrangements.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Survival craft embarkation arrangements. 180.150 Section... (UNDER 100 GROSS TONS) LIFESAVING EQUIPMENT AND ARRANGEMENTS Survival Craft Arrangements and Equipment § 180.150 Survival craft embarkation arrangements. (a) A launching appliance approved under approval...

  18. 46 CFR 188.27-1 - Lifesaving appliances and arrangements.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Lifesaving appliances and arrangements. 188.27-1 Section... VESSELS GENERAL PROVISIONS Lifesaving Appliances and Arrangements § 188.27-1 Lifesaving appliances and arrangements. All lifesaving appliances and arrangements shall be in accordance with the requirements for...

  19. 46 CFR 195.06-1 - Lifesaving appliances and arrangements.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Lifesaving appliances and arrangements. 195.06-1 Section... VESSELS VESSEL CONTROL AND MISCELLANEOUS SYSTEMS AND EQUIPMENT Lifesaving Appliances and Arrangements § 195.06-1 Lifesaving appliances and arrangements. All lifesaving appliances and arrangements shall be...

  20. 46 CFR 90.27-1 - Lifesaving appliances and arrangements.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Lifesaving appliances and arrangements. 90.27-1 Section... VESSELS GENERAL PROVISIONS Lifesaving Appliances and Arrangements § 90.27-1 Lifesaving appliances and arrangements. All lifesaving appliances and arrangements must be in accordance with subchapter W (Lifesaving...

  1. 46 CFR 70.28-1 - Lifesaving appliances and arrangements.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 3 2010-10-01 2010-10-01 false Lifesaving appliances and arrangements. 70.28-1 Section... PROVISIONS Lifesaving Appliances and Arrangements § 70.28-1 Lifesaving appliances and arrangements. All lifesaving appliances and arrangements on passenger vessels must be in accordance with subchapter W...

  2. Creating flexible work arrangements through idiosyncratic deals.

    Science.gov (United States)

    Hornung, Severin; Rousseau, Denise M; Glaser, Jürgen

    2008-05-01

    A survey of 887 employees in a German government agency assessed the antecedents and consequences of idiosyncratic arrangements individual workers negotiated with their supervisors. Work arrangements promoting the individualization of employment conditions, such as part-time work and telecommuting, were positively related to the negotiation of idiosyncratic deals ("i-deals"). Worker personal initiative also had a positive effect on i-deal negotiation. Two types of i-deals were studied: flexibility in hours of work and developmental opportunities. Flexibility i-deals were negatively related and developmental i-deals positively related to work-family conflict and working unpaid overtime. Developmental i-deals were also positively related to increased performance expectations and affective organizational commitment, while flexibility i-deals were unrelated to either. PsycINFO Database Record (c) 2008 APA, all rights reserved.

  3. Storage arrangement for nuclear reactor fuel assemblies

    International Nuclear Information System (INIS)

    Wade, E.E.

    1977-01-01

    Said invention is intended for providing an arrangement of spent fuel assembly storage inside which the space is efficiently used without accumulating a critical mass. The storage is provided for long fuel assemblies having along their longitudinal axis an active part containing the fuel and an inactive part empty of fuel. Said storage arrangement comprises a framework constituting some long-shaped cells designed so as each of them can receive a fuel assembly. Means of axial positioning of said assembly in a cell make it possible to support the fuel assemblies inside the framework according to a spacing ratio, along the cell axis, such as the active part of an assembly is adjacent to the inactive part of the adjacent assemblies [fr

  4. Tandem catalysis: a new approach to polymers.

    Science.gov (United States)

    Robert, Carine; Thomas, Christophe M

    2013-12-21

    The creation of polymers by tandem catalysis represents an exciting frontier in materials science. Tandem catalysis is one of the strategies used by Nature for building macromolecules. Living organisms generally synthesize macromolecules by in vivo enzyme-catalyzed chain growth polymerization reactions using activated monomers that have been formed within cells during complex metabolic processes. However, these biological processes rely on highly complex biocatalysts, thus limiting their industrial applications. In order to obtain polymers by tandem catalysis, homogeneous and enzyme catalysts have played a leading role in the last two decades. In the following feature article, we will describe selected published efforts to achieve these research goals.

  5. Tandem Mirror Reactor Systems Code (Version I)

    International Nuclear Information System (INIS)

    Reid, R.L.; Finn, P.A.; Gohar, M.Y.

    1985-09-01

    A computer code was developed to model a Tandem Mirror Reactor. Ths is the first Tandem Mirror Reactor model to couple, in detail, the highly linked physics, magnetics, and neutronic analysis into a single code. This report describes the code architecture, provides a summary description of the modules comprising the code, and includes an example execution of the Tandem Mirror Reactor Systems Code. Results from this code for two sensitivity studies are also included. These studies are: (1) to determine the impact of center cell plasma radius, length, and ion temperature on reactor cost and performance at constant fusion power; and (2) to determine the impact of reactor power level on cost

  6. Method and arrangement of distillation of shales

    Energy Technology Data Exchange (ETDEWEB)

    Bergh, S V

    1920-03-29

    A method is given of distilling shale and other bituminous materials utilizing the heat from the combustion of the residue, possibly with additional heat from other fuels. It is characterized by the shale, which is arranged in layers, being first submitted to a process of distillation utilizing the heat mentioned, and at the same time recovering the products of distillation, and second the shale being burned without disturbing the layers to any appreciable extent. The patent has 16 more claims.

  7. Experimental evidence of the thermal effect of lubricating oil sprayed in sliding-vane air compressors

    Directory of Open Access Journals (Sweden)

    Gianluca Valenti

    2014-11-01

    Full Text Available A way to increase the efficiency of positive-displacement air compressor is spraying the lube oil to exploit it not only as lubricating and sealing agent but also as thermal ballast. This work seeks the experimental evidence in sliding-vane compressors by measuring the air standard volume flow rate and the electrical power input of three diverse configurations. The first configuration, taken as the reference, employs a conventional injection system comprising calibrated straight orifices. The other two, referred to as advanced, adopt smaller orifices and pressure-swirl full-cone nozzles designed for the purpose; the third configuration utilizes a pump to boost the oil pressure. The laser imagining technique shows that the nozzles generate sprays that break-up within a short distance into spherical droplets, ligaments, ramifications and undefined structures. Tests on the packaged compressors reveal that the advanced configurations provide almost the same air flow rate while utilizing half of the oil because the sprays generate a good sealing. Moreover, the sprayed oil is acting as a thermal ballast because the electrical input is reduced by 3.5% and 3.0%, respectively, if the pump is present or not , while the specific energy requirement, accounting for the slightly reduced air flow, by 2.4% and 2.9%, respectively.

  8. Transition Process from Diffuser Stall to Stage Stall in a Centrifugal Compressor with a Vaned Diffuser

    Directory of Open Access Journals (Sweden)

    Nobumichi Fujisawa

    2017-01-01

    Full Text Available The transition process from a diffuser rotating stall to a stage stall in a centrifugal compressor with a vaned diffuser was investigated by experimental and numerical analyses. From the velocity measurements, it was found that the rotating stall existed on the shroud side of the diffuser passage in the off-design flow condition. The numerical results revealed the typical vortical structure of the diffuser stall. The diffuser stall cell was caused by the systematic vortical structure which consisted of the tornado-type vortex, the longitudinal vortex at the shroud/suction surface corner (i.e., leading edge vortex (LEV, and the vortex in the throat area of the diffuser passages. Furthermore, the stage stall, which rotated within both the impeller and diffuser passages, occurred instead of the diffuser stall as the mass flow rate was decreased. According to the velocity measurements at the diffuser inlet, the diffuser stall which rotated on the shroud side was shifted to the hub side. Then, the diffuser stall moved into the impeller passages and formed the stage stall. Therefore, the stage stall was caused by the development of the diffuser stall, which transferred from the shroud side to the hub side in the vaneless space and expanded to the impeller passages.

  9. Effects of Radial Gap Ratio between Impeller and Vaned Diffuser on Performance of Centrifugal Compressors

    Directory of Open Access Journals (Sweden)

    Mohammadjavad Hosseini

    2017-07-01

    Full Text Available A high-performance centrifugal compressor is needed for numerous industry applications nowadays. The radial gap ratio between the impeller and the diffuser vanes plays an important role in the improvement of the compressor performance. In this paper, the effects of the radial gap ratio on a high-pressure ratio centrifugal compressor are investigated using numerical simulations. The performance and the flow field are compared for six different radial gap ratios and five rotational speeds. The minimal radial gap ratio was 1.04 and the maximal was 1.14. Results showed that reducing the radial gap ratio decreases the choke mass flow rate. For the tip-speed Mach number (impeller inlet with Mu < 1, the pressure recovery and the loss coefficients are not sensitive to the radial gap ratio. However, for Mu ≥ 1, the best radial gap ratio is 1.08 for the pressure recovery and the loss coefficients. Furthermore, the impeller pressure ratio and efficiency are reduced by increasing the radial gap ratio. Finally, the compressor efficiency was compared for different radial gap ratios. For Mu < 1, the radial gap ratio does not have noticeable effects. In comparison, the radial gap ratio of 1.08 has the best performance for Mu ≥ 1.

  10. A Study of Performance Output of a Multivane Air Engine Applying Optimal Injection and Vane Angles

    Directory of Open Access Journals (Sweden)

    Bharat Raj Singh

    2012-01-01

    Full Text Available This paper presents a new concept of the air engine using compressed air as the potential power source for motorbikes, in place of an internal combustion engine. The motorbike is proposed to be equipped with an air engine, which transforms the energy of the compressed air into mechanical motion energy. A mathematical model is presented here, and performance evaluation is carried out on an air-powered novel air turbine engine. The maximum power output is obtained as 3.977 kW (5.50 HP at the different rotor to casing diameter ratios, optimal injection angle 60°, vane angle 45° for linear expansion (i.e., at minimum air consumption when the casing diameter is kept 100 mm, at injection pressure 6 bar (90 psi and speed of rotation 2500 rpm. A prototype air engine is built and tested in the laboratory. The experimental results are also seen much closer to the analytical values, and the performance efficiencies are recorded around 70% to 95% at the speed of rotation 2500–3000 rpm.

  11. The NTF Inlet Guide Vanes Thermal Gradient Problem and Its Mitigation

    Science.gov (United States)

    Venkat, Venki S.; Paryz, Roman W.; Bissett, Owen W.; Kilgore, W.

    2013-01-01

    The National Transonic Facility (NTF) utilizes Inlet Guide Vanes (IGV) to provide precise, quick response Mach number control for the tunnel. During cryogenic operations, the massive IGV structure can experience large thermal gradients, measured as "Delta T or (Delta)T", between the IGV ring and its support structure called the transfer case. If these temperature gradients are too large, the IGV structure can be stressed beyond its safety limit and cease operation. In recent years, (Delta)T readings exceeding the prescribed safety limits were observed frequently during cryogenic operations, particularly during model access. The tactical operation methods of the tunnel to minimize (Delta)T did not always succeed. One obvious option to remedy this condition is to warm up the IGV structure by disabling the main drive operation, but this "natural" warm up method can takes days in some cases, resulting in productivity loss. This paper documents the thermal gradient problem associated with the IGV structure during cryogenic operation and how the facility has recently achieved an acceptable mitigation which has resulted in improved efficiency of operations.

  12. Numerical Study of Compact Plate-Fin Heat Exchanger for Rotary-Vane Gas Refrigeration Machine

    Directory of Open Access Journals (Sweden)

    V. V. Trandafilov

    2017-10-01

    Full Text Available Plate-fin heat exchangers are widely used in refrigeration technique. They are popular because of their compactness and excellent heat transfer performance. Here we present a numerical model for the development, research and optimization of a plate-fin heat exchanger for a rotary-vane gas refrigeration machine. The method of analysis by graphic method of plate - fin heat exchanger is proposed. The model describes the effects of secondary parameters such as axial thermal conductivity through a metal matrix of the heat exchanger. The influence of geometric parameters and heat transfer coefficient is studied. Graphs of dependences of length, efficiency of a fin and pressure drop in a heat exchanger on the thickness of the fin and the number of fins per meter are obtained. To analyze the results of numerical simulation, the heat exchanger was designed in the Aspen HYSYS program. The simulation results show that the total deviation from the proposed numerical model is not more than 15%. 

  13. Active unsteady aerodynamic suppression of rotating stall in an incompressible flow centrifugal compressor with vaned diffuser

    Science.gov (United States)

    Lawless, Patrick B.; Fleeter, Sanford

    1991-01-01

    A mathematical model is developed to analyze the suppression of rotating stall in an incompressible flow centrifugal compressor with a vaned diffuser, thereby addressing the important need for centrifugal compressor rotating stall and surge control. In this model, the precursor to to instability is a weak rotating potential velocity perturbation in the inlet flow field that eventually develops into a finite disturbance. To suppress the growth of this potential disturbance, a rotating control vortical velocity disturbance is introduced into the impeller inlet flow. The effectiveness of this control is analyzed by matching the perturbation pressure in the compressor inlet and exit flow fields with a model for the unsteady behavior of the compressor. To demonstrate instability control, this model is then used to predict the control effectiveness for centrifugal compressor geometries based on a low speed research centrifugal compressor. These results indicate that reductions of 10 to 15 percent in the mean inlet flow coefficient at instability are possible with control waveforms of half the magnitude of the total disturbance at the inlet.

  14. Core arrangement in BWR type reactors

    International Nuclear Information System (INIS)

    Asano, Masayuki.

    1981-01-01

    Purpose: To decrease the number of fuel assemblies whose locations are to be changed upon fuel exchange, as well as unify the power distribution in the core by arranging, in a chess board configuration, a plurality pattern of unit reactor lattices each containing fuel assemblies of different burnup degrees in orthogonal positions to each other. Constitution: A first pattern of unit reactor lattice is formed by disposing fuel assemblies of burnup degree 1 and fuel assemblies of burnup degree 3 at orthogonal positions to each other. A second pattern of unit reactor lattice is formed by disposing fuel assemblies of burnup degree 2 and fuel assemblies of burnup degree 1 at orthogonal positions to each other. The unit lattices each in such a dispositions are arranged in a chess board arrangement. Since, the fuel assemblies of the burnup degree 1 in the first pattern unit lattices proceed to the burnup degree 2 and the fuel assemblies of the burnup degree 2 in the second pattern unit lattices proceed to the burnup degree 3 up to the fuel exchange stage, fuel exchange and movement have only to be made, not for those fuel assemblies, but for another half of the fuel assemblies. (Kawakami, Y.)

  15. Recurring part arrangements in shape collections

    KAUST Repository

    Zheng, Youyi

    2014-05-01

    Extracting semantically related parts across models remains challenging, especially without supervision. The common approach is to co-analyze a model collection, while assuming the existence of descriptive geometric features that can directly identify related parts. In the presence of large shape variations, common geometric features, however, are no longer sufficiently descriptive. In this paper, we explore an indirect top-down approach, where instead of part geometry, part arrangements extracted from each model are compared. The key observation is that while a direct comparison of part geometry can be ambiguous, part arrangements, being higher level structures, remain consistent, and hence can be used to discover latent commonalities among semantically related shapes. We show that our indirect analysis leads to the detection of recurring arrangements of parts, which are otherwise difficult to discover in a direct unsupervised setting. We evaluate our algorithm on ground truth datasets and report advantages over geometric similarity-based bottom-up co-segmentation algorithms. © 2014 The Author(s) Computer Graphics Forum © 2014 The Eurographics Association and John Wiley & Sons Ltd. Published by John Wiley & Sons Ltd.

  16. The making of local hospital discharge arrangements

    DEFF Research Database (Denmark)

    Burau, Viola; Bro, Flemming

    2015-01-01

    Background Timely discharge is a key component of contemporary hospital governance and raises questions about how to move to more explicit discharge arrangements. Although associated organisational changes closely intersect with professional interests, there are relatively few studies in the lite......Background Timely discharge is a key component of contemporary hospital governance and raises questions about how to move to more explicit discharge arrangements. Although associated organisational changes closely intersect with professional interests, there are relatively few studies...... in the literature on hospital discharge that explicitly examine the role of professional groups. Recent contributions to the literature on organisational studies of the professions help to specify how professional groups in hospitals contribute to the introduction and routinisation of discharge arrangements...... for patients with prostate cancer in two hospitals in Denmark. This represents a typical case that involves changes in professional practice without being first and foremost a professional project. The multiple case design also makes the findings more robust. The analysis draws from 12 focus groups...

  17. Recurring part arrangements in shape collections

    KAUST Repository

    Zheng, Youyi; Cohen-Or, Daniel; Averkiou, Melinos; Mitra, Niloy J.

    2014-01-01

    Extracting semantically related parts across models remains challenging, especially without supervision. The common approach is to co-analyze a model collection, while assuming the existence of descriptive geometric features that can directly identify related parts. In the presence of large shape variations, common geometric features, however, are no longer sufficiently descriptive. In this paper, we explore an indirect top-down approach, where instead of part geometry, part arrangements extracted from each model are compared. The key observation is that while a direct comparison of part geometry can be ambiguous, part arrangements, being higher level structures, remain consistent, and hence can be used to discover latent commonalities among semantically related shapes. We show that our indirect analysis leads to the detection of recurring arrangements of parts, which are otherwise difficult to discover in a direct unsupervised setting. We evaluate our algorithm on ground truth datasets and report advantages over geometric similarity-based bottom-up co-segmentation algorithms. © 2014 The Author(s) Computer Graphics Forum © 2014 The Eurographics Association and John Wiley & Sons Ltd. Published by John Wiley & Sons Ltd.

  18. Frequency Arrangement For 700 MHz Band

    Directory of Open Access Journals (Sweden)

    Ancans G.

    2015-02-01

    Full Text Available The 694-790 MHz (700 MHz band was allocated by the 2012 World Radiocommunication Conference (WRC-12 in ITU Region 1 (Europe included, to the mobile service on a co-primary basis with other services to which this band was allocated on the primary basis and identified for the International Mobile Telecommunications (IMT. At the same time, the countries of Region 1 will be able also to continue using these frequencies for their broadcasting services if necessary. This allocation will be effective immediately after 2015 World Radiocommunication Conference (WRC-15. In order to make the best possible use of this frequency band for mobile service, a worldwide harmonized frequency arrangement is to be prepared to allow for large economies of scale and international roaming as well as utilizing the available spectrum in the best possible way, minimizing possible interference between services, facilitating deployment and cross-border coordination. The authors analyze different possible frequency arrangements and conclude on the frequency arrangement most suitable for Europe.

  19. The Influence of the Phase Difference between the Crank Angle of the Pilot and that of the Stoker on the Drag Acting on a Tandem Bike

    Directory of Open Access Journals (Sweden)

    Kazuya Seo

    2018-02-01

    Full Text Available Two wind tunnel experiments were carried out to investigate the drag acting on a tandem bike. One experiment involved measurement of the drag acting on two full-scale human models on a tandem. These two human models can pedal the tandem. In the other experiment, two oscillating cylinders were used as a simplified model of the legs of the pilot and the stoker. These were arranged to represent the legs of the riders on a tandem. Measurements of the drag on this model were made. It was found that the drag decreases when the crank angle of the stoker’s pedal is delayed with respect to the pilot’s pedal.

  20. TASKA - Tandem Spiegelmaschine Karlsruhe. Vol. 1

    International Nuclear Information System (INIS)

    1982-06-01

    TASKA (Tandem Spiegelmaschine Karlsruhe) is a near term engineering test facility based on a tandem mirror concept with thermal barriers. The main objectives of this study were to develop a preconceptual design of a facility that could provide engineering design information for a Demonstration Fusion Power Reactor. Thus TASKA has to serve as testbed for technologies of plasma engineering, superconducting magnets, materials, plasma heating, breeding and test blankets, tritium technology, and remote handling. (orig.) [de

  1. Feasibility study on tandem fuel cycle

    International Nuclear Information System (INIS)

    Han, P.S.; Suh, I.S.; Rim, C.S.; Kim, B.K.; Suh, K.S.; Ro, S.K.; Juhn, P.I.; Kim, S.Y.

    1983-01-01

    The objective of this feasibility study is to review and assess the current state of technology concerning the tandem fuel cycle. Based on the results from this study, a long-term development plan suitable for Korea has been proposed for this cycle, i.e., the PWR → CANDU tandem fuel cycle which used plutonium and uranium, recovered from spent PWR fuel by co-processing, as fuel material for CANDU reactors. (Author)

  2. TASKA - Tandem Spiegelmaschine Karlsruhe. Vol. 2

    International Nuclear Information System (INIS)

    1982-06-01

    TASKA (Tandem Spiegelmaschine Karlsruhe) is a near term engineering test facility based on a tandem mirror concept with thermal barriers. The main objectives of this study were to develop a preconceptual design of a facility that could provide engineering design information for a Demonstration Fusion Power Reactor. Thus TASKA has to serve as testbed for technologies of plasma engineering, superconducting magnets, materials, plasma heating, breeding and test blankets, tritium technology, and remote handling. (orig.) [de

  3. North-American MP Tandem accelerators

    International Nuclear Information System (INIS)

    Wegner, H.E.; Thieberger, P.

    1977-01-01

    There are six North-American MP Tandem accelerators: Yale; Minnesota; Chalk River; Rochester; and two at Brookhaven. The current status and operating characteristics of these six tandem accelerators are discussed. Upgrade and special improvements of the different machines is reviewed and new developments since the last Electrostatic Conference are discussed in detail. The overall operating characteristics of the different machines during the last year of operation are compared

  4. T2-weighted liver MRI using the multiVane technique at 3T: Comparison with conventional T2-weighted MRI

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Kyung A [Dept. of Radiology, Myongji Hospital, Seonam University College of Medicine, Goyang (Korea, Republic of); Kim, Young Kon; Jeong, Woo Kyoung; Choi, Dong Il; Lee, Won Jae [Dept. of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of); Kim, Eun Ju [Philips Healthcare Korea, Philips, Seoul (Korea, Republic of); Jung, Sin Ho; Baek, Sun Young [Biostatistics and Clinical Epidemiology Center, Samsung Medical Center, Seoul (Korea, Republic of)

    2015-10-15

    To assess the value of applying MultiVane to liver T2-weighted imaging (T2WI) compared with conventional T2WIs with emphasis on detection of focal liver lesions. Seventy-eight patients (43 men and 35 women) with 86 hepatic lesions and 20 pancreatico-biliary diseases underwent MRI including T2WIs acquired using breath-hold (BH), respiratory-triggered (RT), and MultiVane technique at 3T. Two reviewers evaluated each T2WI with respect to artefacts, organ sharpness, and conspicuity of intrahepatic vessels, hilar duct, and main lesion using five-point scales, and made pairwise comparisons between T2WI sequences for these categories. Diagnostic accuracy (Az) and sensitivity for hepatic lesion detection were evaluated using alternative free-response receiver operating characteristic analysis. MultiVane T2WI was significantly better than BH-T2WI or RT-T2WI for organ sharpness and conspicuity of intrahepatic vessels and main lesion in both separate reviews and pairwise comparisons (p < 0.001). With regard to motion artefacts, MultiVane T2WI or BH-T2WI was better than RT-T2WI (p < 0.001). Conspicuity of hilar duct was better with BH-T2WI than with MultiVane T2WI (p = 0.030) or RT-T2WI (p < 0.001). For detection of 86 hepatic lesions, sensitivity (mean, 97.7%) of MultiVane T2WI was significantly higher than that of BH-T2WI (mean, 89.5%) (p = 0.008) or RT-T2WI (mean, 84.9%) (p = 0.001). Applying the MultiVane technique to T2WI of the liver is a promising approach to improving image quality that results in increased detection of focal liver lesions compared with conventional T2WI.

  5. Vortex shedding from tandem cylinders

    Science.gov (United States)

    Alam, Md. Mahbub; Elhimer, Mehdi; Wang, Longjun; Jacono, David Lo; Wong, C. W.

    2018-03-01

    An experimental investigation is conducted on the flow around tandem cylinders for ranges of diameter ratio d/ D = 0.25-1.0, spacing ratio L/ d = 5.5-20, and Reynolds number Re = 0.8 × 104-2.42 × 104, where d and D are the diameters of the upstream and downstream cylinders, respectively, L is the distance from the upstream cylinder center to the forward stagnation point of the downstream one. The focus is given on examining the effects of d/ D, L/ d and Re on Strouhal number St, flow structures and fluid forces measured using hotwire, particle image velocimetry (PIV) and load cell measurement techniques, respectively. Changes in d/ D and L/ d in the ranges examined lead to five flow regimes, namely lock-in, intermittent lock-in, no lock-in, subharmonic lock-in and shear-layer reattachment regimes. Time-mean drag coefficient ( C D) and fluctuating drag and lift coefficients ({C^'D} and {C^'L}) are more sensitive to L/ d than d/ D. The scenario is opposite for St where d/ D is more prominent than L/ d to change the St. The detailed facet of the dependence on d/ D and L/ d of C D, {C^'D}, {C^'L} and St is discussed based on shear-layer velocity, approaching velocity, vortex formation length, and wake width.

  6. Jet spoiler arrangement for wind turbine

    Science.gov (United States)

    Cyrus, J. D.; Kablec, E. G.; Klimas, P. C.

    1983-09-01

    An air jet spoiler arrangement is provided for a Darrieus-type vertical axis wind-powered turbine. Air is drawn into hollow turbine blades through air inlets at the end thereof and is ejected in the form of air jets through small holes or openings provided along the lengths of the blades. The air jets create flow separation at the surfaces of the turbine blades, thereby including stal conditions and reducing the output power. A feedback control unit senses the power output of the turbine and controls the amount of air drawn into the air inlets accordingly.

  7. Jet spoiler arrangement for wind turbine

    Science.gov (United States)

    Cyrus, Jack D.; Kadlec, Emil G.; Klimas, Paul C.

    1985-01-01

    An air jet spoiler arrangement is provided for a Darrieus-type vertical axis wind-powered turbine. Air is drawn into hollow turbine blades through air inlets at the ends thereof and is ejected in the form of air jets through small holes or openings provided along the lengths of the blades. The air jets create flow separation at the surfaces of the turbine blades, thereby inducing stall conditions and reducing the output power. A feedback control unit senses the power output of the turbine and controls the amount of air drawn into the air inlets accordingly.

  8. Improved microgrid arrangement for integrated imaging polarimeters.

    Science.gov (United States)

    LeMaster, Daniel A; Hirakawa, Keigo

    2014-04-01

    For almost 20 years, microgrid polarimetric imaging systems have been built using a 2×2 repeating pattern of polarization analyzers. In this Letter, we show that superior spatial resolution is achieved over this 2×2 case when the analyzers are arranged in a 2×4 repeating pattern. This unconventional result, in which a more distributed sampling pattern results in finer spatial resolution, is also achieved without affecting the conditioning of the polarimetric data-reduction matrix. Proof is provided theoretically and through Stokes image reconstruction of synthesized data.

  9. A Circularly Arranged Sextuple Triptycene Gear Molecule.

    Science.gov (United States)

    Ube, Hitoshi; Yamada, Ryo; Ishida, Jun-Ichi; Sato, Hiroyasu; Shiro, Motoo; Shionoya, Mitsuhiko

    2017-11-22

    Herein we report the synthesis of a circularly arranged sextuple triptycene gear molecule, hexakis(10-dodecyloxy-9-triptycyl)ethynylbenzene, via the trimerization of the corresponding triyne with a cobalt catalyst. The six triptycene gears are closely engaged with each other as confirmed by single crystal X-ray structure analysis, and their motion in solution was established by NMR spectroscopy. Notably, when one bulky RuCp* complex was attached to one triptycene gear, the whole movement of the six gears was highly restricted via their mechanical engagement. Development of such a multigear molecule would provide a structural basis for molecular motion transmission systems with a switching function.

  10. Monitoring arrangement for vented nuclear fuel elements

    International Nuclear Information System (INIS)

    Campana, R.J.

    1981-01-01

    In a nuclear fuel reactor core, fuel elements are arranged in a closely packed hexagonal configuration, each fuel element having diametrically opposed vents permitting 180 0 rotation of the fuel elements to counteract bowing. A grid plate engages the fuel elements and forms passages for communicating sets of three, four or six individual vents with respective monitor lines in order to communicate vented radioactive gases from the fuel elements to suitable monitor means in a manner readily permitting detection of leakage in individual fuel elements

  11. Method of operating an electromagnet arrangement

    International Nuclear Information System (INIS)

    Goldie, F.T.D.

    1988-01-01

    A method is described for operating an electromagnet arrangement comprising a main electromagnet and a number of correction coils for applying correction fields to the field produced by the main electromagnet to produce a resultant desired homogeneous magnetic field in a given volume. The method comprises obtaining the least squares fit values for the correction coil currents. If the required current in any coil lies outside a range of permissible values for that coil current a special procedure is described to find the selection of coil currents providing the lowest squared deviation between the desired and actual fields consistent with the permissible currents in the coils. (author)

  12. Rotor boundary layer development with inlet guide vane (IGV) wake impingement

    Science.gov (United States)

    Jia, Lichao; Zou, Tengda; Zhu, Yiding; Lee, Cunbiao

    2018-04-01

    This paper examines the transition process in a boundary layer on a rotor blade under the impingement of an inlet guide vane wake. The effects of wake strengths and the reduced frequency on the unsteady boundary layer development on a low-speed axial compressor were investigated using particle image velocimetry. The measurements were carried out at two reduced frequencies (fr = fIGVS0/U2i, fr = 1.35, and fr = 0.675) with the Reynolds number, based on the blade chord and the isentropic inlet velocity, being 97 500. At fr = 1.35, the flow separated at the trailing edge when the wake strength was weak. However, the separation was almost totally suppressed as the wake strength increased. For the stronger wake, both the wake's high turbulence and the negative jet behavior of the wake dominated the interaction between the unsteady wake and the separated boundary layer on the suction surface of the airfoil. The boundary layer displacement thickened first due to the negative jet effect. Then, as the disturbances developed underneath the wake, the boundary layer thickness reduced gradually. The high disturbance region convected downstream at a fraction of the free-stream velocity and spread in the streamwise direction. The separation on the suction surface was suppressed until the next wake's arrival. Because of the long recovery time at fr = 0.675, the boundary layer thickened gradually as the wake convected further downstream and finally separated due to the adverse pressure gradient. The different boundary layer states in turn affected the development of disturbances.

  13. UK nuclear terrorism insurance arrangements: an overview

    International Nuclear Information System (INIS)

    Tetley, M. G.

    2004-01-01

    The risk of terrorism in the UK is not new, but since the New York World Trade Centre attacks in 2001, the potential scale of any terrorist attack has required a considerable reassessment. With UK foreign policy closely aligned to that of the USA, the UK security services now consider it is simply a matter of when and no longer if the UK is attacked. For insurers of any type this fact would cause concern; for insurers involved in high profile and potentially catastrophic loss targets such as nuclear power plants, any attack could have a severe impact on solvency and shareholder's funds. This paper's objective is to describe the terrorism insurance arrangements put in place in the U.K. both before and after the September 2001 attacks. These arrangements have been designed both to safeguard insurers' solvency and to ensure that the nuclear industry and general public can continue to be reassured by the availability of insurance should an attack ever occur.(author)

  14. Tax issues in structuring gas process arrangements

    International Nuclear Information System (INIS)

    Iverach, R.J.

    1999-01-01

    The current status of various tax issues regarding ownership, operation and financing of gas processing facilities in Canada was discussed. Frequently, energy companies are not taxed because of their large pools of un-depreciated capital cost and other resource related accounts. In addition, their time horizons for taxability are being extended in line with the expansion of their businesses. However, other investors are fully taxable, hence they wish to shelter their income through the use of tax efficient investment arrangements. This paper provides a detailed description of the tax treatment of gas processing facilities, tax implications of various structures between the producer and the investor such as lease, processing fee arrangements etc., and use of 'Canadian Renewable and Conservation Expense' (CRCE) for cogeneration projects within processing plants. All these need to be considered before completing a financing transaction involving a gas processing facility, since the manner in which the transaction is completed will determine the advantages and benefits from an income tax perspective. The accounting and legal aspects must be similarly scrutinized to ensure that the intended results for all parties are achieved. 8 figs

  15. The VanE operon in Enterococcus faecalis N00-410 is found on a putative integrative and conjugative element, Tn6202.

    Science.gov (United States)

    Boyd, D A; Mulvey, M R

    2013-02-01

    To date no complete genetic structure of acquired DNA harbouring a d-Ala-d-Ser operon in an Enterococcus is known. We wished to characterize the acquired DNA harbouring the vanE operon located in the Enterococcus faecalis N00-410 chromosome. Whole genome sequencing of E. faecalis N00-410 was conducted by massively parallel sequencing. Two sequence contigs harbouring the vanE region were linked by PCR and the acquired DNA harbouring the vanE operon was completely characterized. Excision/integration of the region was determined by PCR and transfer attempted by conjugation. The regions flanking the vanE operon were analysed and a total of 42 open reading frames were identified in a region flanked by inverted terminal and direct repeats (Tn6202). Tn6202 could be excised from the chromosome, circularized and the target site rejoined, but transfer could not be demonstrated. The vanE operon was found on the putative integrative and conjugative element Tn6202 in the E. faecalis N00-410 chromosome. This represents the first characterization of acquired DNA harbouring a D-Ala-D-Ser operon.

  16. Numerical research on the effects of impeller pump-out vanes on axial force in a solid-liquid screw centrifugal pump

    International Nuclear Information System (INIS)

    Cheng, X R; Li, R N; Gao, Y; Guo, W L

    2013-01-01

    A commercial CFD code has been used to predict the performance of a screw centrifugal pump with pump-out vanes, especially when changing regularity of impeller axial force based on the solid-liquid two-phase flow. The Unsteady Reynolds Averaged Navier-Stokes (URANS) approach has been applied to solve the unsteady, incompressible, three-dimensional turbulent. The SIMPLEC algorithm, standard wall functions and mix two-phase flow model were applied. The RNG k ε-model was used to account the turbulence effects. By changing the number of impeller pump-out vanes and width, six different screw centrifugal pump numerical simulation projects were given, and each scheme in the different solid volume fraction were calculated respectively. The change rules of axial force, velocity and pressure distribution of flow field were obtained on the different condition and different volume fraction. The results showed that the axial forces values based solid-fluid two-phase greater than based single-phase clear water, but both changing regularity of the axial force were consistent; as same condition, the same solid-phase volume concentration, with the increase of pump-out vanes number or width, the impeller axial force increased as well. Meanwhile the number of the pump-out vanes and the width of pump-out vanes in balancing the impeller axial force, there are the most optimal value

  17. Change of performance of a horizontal wind turbine with V type tip vane%风力机加V型小翼后的性能变化

    Institute of Scientific and Technical Information of China (English)

    贾瑞博; 汪建文

    2011-01-01

    试验和数值模拟证明,在风力机叶片的叶尖添加小翼,可以提高风能转化效率.为了清楚地了解小翼对风力机动力放大的影响,文章基于叶轮周围流场的数值模拟结果,分析了加V型小翼和不加小翼的风力机流场-速度场和压力场特性.可以看出,小翼对风力机叶片叶端的影响较大,风力机叶尖的漩涡强度降低,能量转换效率提高.%It was proved that a tip vane could improve thewind turbine's efficiency by the test and the numerical simulation. In order to distinctly understand the power augmentation effect of the wind turbine by the tip vane, this paper analyzed the flow field of the wind turbine with the V type tip vane and without a tip vane, as well as the characteristics of the velocity field and the pressure field, which based on the numerical simulation result of the flow field of the wind turbine. The tip vane has more influence to the blade tip of the wind turbine. The vortex intensity around the blade tip was reduced and the energy transformation efficiency was improved.

  18. Prospects for the domestic production of large-sized cast blades and vanes for industrial gas turbines

    Science.gov (United States)

    Kazanskiy, D. A.; Grin, E. A.; Klimov, A. N.; Berestevich, A. I.

    2017-10-01

    Russian experience in the production of large-sized cast blades and vanes for industrial gas turbines is analyzed for the past decades. It is noted that the production of small- and medium-sized blades and vanes made of Russian alloys using technologies for aviation, marine, and gas-pumping turbines cannot be scaled for industrial gas turbines. It is shown that, in order to provide manufacturability under large-scale casting from domestic nickel alloys, it is necessary to solve complex problems in changing their chemical composition, to develop new casting technologies and to optimize the heat treatment modes. An experience of PAO NPO Saturn in manufacturing the blades and vanes made of ChS88U-VI and IN738-LC foundry nickel alloys for the turbines of the GTE-110 gas turbine unit is considered in detail. Potentialities for achieving adopted target parameters for the mechanical properties of working blades cast from ChS88UM-VI modified alloy are established. For the blades made of IN738-LC alloy manufactured using the existing foundry technology, a complete compliance with the requirements of normative and technical documentation has been established. Currently, in Russia, the basis of the fleet of gas turbine plants is composed by foreign turbines, and, for the implementation of the import substitution program, one can use the positive experience of PAO NPO Saturn in casting blades from IN738-LC alloy based on a reverse engineering technique. A preliminary complex of studies of the original manufacturer's blades should be carried out, involving, first of all, the determination of geometric size using modern measurement methods as well as the studies on the chemical compositions of the used materials (base metal and protective coatings). Further, verifying the constructed calculation models based on the obtained data, one could choose available domestic materials that would meet the operating conditions of the blades according to their heat resistance and corrosion

  19. Extended residence time centrifugal contactor design modification and centrifugal contactor vane plate valving apparatus for extending mixing zone residence time

    Science.gov (United States)

    Wardle, Kent E.

    2017-06-06

    The present invention provides an annular centrifugal contactor, having a housing adapted to receive a plurality of flowing liquids; a rotor on the interior of the housing; an annular mixing zone, wherein the annular mixing zone has a plurality of fluid retention reservoirs with ingress apertures near the bottom of the annular mixing zone and egress apertures located above the ingress apertures of the annular mixing zone; and an adjustable vane plate stem, wherein the stem can be raised to restrict the flow of a liquid into the rotor or lowered to increase the flow of the liquid into the rotor.

  20. Tandem mass spectrometry at low kinetic energy

    International Nuclear Information System (INIS)

    Cooks, R.G.; Hand, O.W.

    1987-01-01

    Recent progress in mass spectrometry, as applied to molecular analysis, is reviewed with emphasis on tandem mass spectrometry. Tandem instruments use multiple analyzers (sector magnets, quadrupole mass filters and time-of-flight devices) to select particular molecules in ionic form, react them in the gas-phase and then record the mass, momenta or kinetic energies of their products. The capabilities of tandem mass spectrometry for identification of individual molecules or particular classes of compounds in complex mixtures are illustrated. Several different types of experiments can be run using a tandem mass spectrometer; all share the feature of sifting the molecular mixture being analyzed on the basis of chemical properties expressed in terms of ionic mass, kinetic energy or charge state. Applications of mass spectrometry to biological problems often depend upon desorption methods of ionization in which samples are bombarded with particle beams. Evaporation of preformed charged species from the condensed phase into the vacuum is a particularly effective method of ionization. It is suggested that the use of accelerator mass spectrometers be extended to include problems of molecular analysis. In such experiments, low energy tandem mass spectrometry conducted in the eV or keV range of energies, would be followed by further characterization of the production ion beam using high selective MeV collision processes

  1. Tandemly Arrayed Genes in Vertebrate Genomes

    Directory of Open Access Journals (Sweden)

    Deng Pan

    2008-01-01

    Full Text Available Tandemly arrayed genes (TAGs are duplicated genes that are linked as neighbors on a chromosome, many of which have important physiological and biochemical functions. Here we performed a survey of these genes in 11 available vertebrate genomes. TAGs account for an average of about 14% of all genes in these vertebrate genomes, and about 25% of all duplications. The majority of TAGs (72–94% have parallel transcription orientation (i.e., they are encoded on the same strand in contrast to the genome, which has about 50% of its genes in parallel transcription orientation. The majority of tandem arrays have only two members. In all species, the proportion of genes that belong to TAGs tends to be higher in large gene families than in small ones; together with our recent finding that tandem duplication played a more important role than retroposition in large families, this fact suggests that among all types of duplication mechanisms, tandem duplication is the predominant mechanism of duplication, especially in large families. Finally, several species have a higher proportion of large tandem arrays that are species-specific than random expectation.

  2. 48 CFR 28.304 - Risk-pooling arrangements.

    Science.gov (United States)

    2010-10-01

    ... CONTRACTING REQUIREMENTS BONDS AND INSURANCE Insurance 28.304 Risk-pooling arrangements. Agencies may establish risk-pooling arrangements. These arrangements are designed to use the services of the insurance industry for safety engineering and the handling of claims at minimum cost to the Government. The agency...

  3. 22 CFR 92.63 - Arrangement of papers.

    Science.gov (United States)

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Arrangement of papers. 92.63 Section 92.63... and Letters Rogatory § 92.63 Arrangement of papers. Unless special instructions to the contrary are received, the various papers comprising the completed record of the depositions should usually be arranged...

  4. 46 CFR 117.150 - Survival craft embarkation arrangements.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Survival craft embarkation arrangements. 117.150 Section... EQUIPMENT AND ARRANGEMENTS Survival Craft Arrangements and Equipment § 117.150 Survival craft embarkation... apparatus when either— (1) The embarkation station for the survival craft is on a deck more than 4.5 meters...

  5. 46 CFR 108.525 - Survival craft number and arrangement.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Survival craft number and arrangement. 108.525 Section... UNITS DESIGN AND EQUIPMENT Lifesaving Equipment § 108.525 Survival craft number and arrangement. (a... arrangement of survival craft: (1) Lifeboats with an aggregate capacity to accommodate the total number of...

  6. Entry into and Consequences of Nonstandard Work Arrangements.

    Science.gov (United States)

    Rothstein, Donna S.

    1996-01-01

    Explores the impact on workers of being in a nonstandard employment arrangement. Examines the distribution of workers among various arrangements and looks at aspects of work behavior and life events that may have influenced their working in a nonstandard arrangement. (Author/JOW)

  7. European top managers' support for work-life arrangements

    NARCIS (Netherlands)

    Been, W.M.|info:eu-repo/dai/nl/357424662

    2015-01-01

    In recent decades, work-life arrangements increasingly became an integral part of the organization of work. Arrangements such as telecommuting, flextime, part-time hours, and various types of leave arrangements are available to employees in many organizations. Top managers, such as CEOs, CFOs and

  8. 47 CFR 1.9020 - Spectrum manager leasing arrangements.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 1 2010-10-01 2010-10-01 false Spectrum manager leasing arrangements. 1.9020... Leasing General Policies and Procedures § 1.9020 Spectrum manager leasing arrangements. (a) Overview... may enter into a spectrum manager leasing arrangement, without the need for prior Commission approval...

  9. Finding an optimal seating arrangement for employees

    Directory of Open Access Journals (Sweden)

    Ninoslav Čerkez

    2015-10-01

    Full Text Available The paper deals with modelling a specifc problem called the Optimal Seating Arrangement (OSA as an Integer Linear Program and demonstrated that the problem can be efficiently solved by combining branch-and-bound and cutting plane methods. OSA refers to a specific scenario that could possibly happen in a corporative environment, i.e. when a company endeavors to minimize travel costs when employees travel to an organized event. Each employee is free to choose the time to travel to and from an event and it depends on personal reasons. The paper differentiates between using different travel possibilities in the OSA problem, such as using company assigned or a company owned vehicles, private vehicles or using public transport, if needed. Also, a user-friendly web application was made and is available to the public for testing purposes.

  10. Grinding arrangement for ball nose milling cutters

    Science.gov (United States)

    Burch, C. F. (Inventor)

    1974-01-01

    A grinding arrangement for spiral fluted ball nose end mills and like tools includes a tool holder for positioning the tool relative to a grinding wheel. The tool is mounted in a spindle within the tool holder for rotation about its centerline and the tool holder is pivotably mounted for angular movement about an axis which intersects that centerline. A follower arm of a cam follower secured to the spindle cooperates with a specially shaped cam to provide rotation of the tool during the angular movement of the tool holder during the grinding cycle, by an amount determined by the cam profile. In this way the surface of the cutting edge in contact with the grinding wheel is maintained at the same height on the grinding wheel throughout the angular movement of the tool holder during the grinding cycle.

  11. Considerations on impact factors and institutional arrangements

    International Nuclear Information System (INIS)

    1979-04-01

    The Delegation makes three comments on the work of the Group. First, the Group should consider the development of international safety standards governing occupational and environmental protection. Non-proliferation measures should not override these standards. Second, safeguards for reprocessing and plutonium recycle must be improved. The Japanese INFCE/DEP./WG-4/122 and French INFCE/DEP./WG-4/58 proposals are valuable contributions to this objective but the Group as a whole should make a broad assessment of safeguards. Lastly, the Delegation supports the development of new institutional arrangements for the fuel cycle which balance the rights and obligations of both suppliers and customers. In particular, the establishment of International Plutonium Storage is supported

  12. High mass isotope separation process and arrangement

    International Nuclear Information System (INIS)

    Eerkens, J.W.

    1978-01-01

    An isotope separation arrangement for separating a preselected isotope from a mixture of chemically identical but isotopically different molecules by either photon-induced pure rovibrational or vibronic selective excitation of the molecules containing the atoms of the isotope to be separated from a lower to a higher energy state, and a chemical reaction of the higher energy state molecules with a chemically reactive agent to form a chemical compound containing primarily the atoms of isotope to be separated in a physicochemical state different from the physicochemical state of the mixture of chemically identical but isotopically different molecules. The chemical compound containing the atoms of the isotope to be separated may be subsequently processed to obtain the isotope

  13. Factored Facade Acquisition using Symmetric Line Arrangements

    KAUST Repository

    Ceylan, Duygu

    2012-05-01

    We introduce a novel framework for image-based 3D reconstruction of urban buildings based on symmetry priors. Starting from image-level edges, we generate a sparse and approximate set of consistent 3D lines. These lines are then used to simultaneously detect symmetric line arrangements while refining the estimated 3D model. Operating both on 2D image data and intermediate 3D feature representations, we perform iterative feature consolidation and effective outlier pruning, thus eliminating reconstruction artifacts arising from ambiguous or wrong stereo matches. We exploit non-local coherence of symmetric elements to generate precise model reconstructions, even in the presence of a significant amount of outlier image-edges arising from reflections, shadows, outlier objects, etc. We evaluate our algorithm on several challenging test scenarios, both synthetic and real. Beyond reconstruction, the extracted symmetry patterns are useful towards interactive and intuitive model manipulations.

  14. Investigation of Blade-row Flow Distributions in Axial-flow-compressor Stage Consisting of Guide Vanes and Rotor-blade Row

    Science.gov (United States)

    Mahoney, John J; Dugan, Paul D; Budinger, Raymond E; Goelzer, H Fred

    1950-01-01

    A 30-inch tip-diameter axial-flow compressor stage was investigated with and without rotor to determine individual blade-row performance, interblade-row effects, and outer-wall boundary-layer conditions. Velocity gradients at guide-vane outlet without rotor approximated design assumptions, when the measured variation of leaving angle was considered. With rotor in operation, Mach number and rotor-blade effects changed flow distribution leaving guide vanes and invalidated design assumption of radial equilibrium. Rotor-blade performance correlated interpolated two-dimensional results within 2 degrees, although tip stall was indicated in experimental and not two-dimensional results. Boundary-displacement thickness was less than 1.0 and 1.5 percent of passage height after guide vanes and after rotor, respectively, but increased rapidly after rotor when tip stall occurred.

  15. Minimum Energy Requirements in Complex Distillation Arrangements

    Energy Technology Data Exchange (ETDEWEB)

    Halvorsen, Ivar J.

    2001-07-01

    Distillation is the most widely used industrial separation technology and distillation units are responsible for a significant part of the total heat consumption in the world's process industry. In this work we focus on directly (fully thermally) coupled column arrangements for separation of multicomponent mixtures. These systems are also denoted Petlyuk arrangements, where a particular implementation is the dividing wall column. Energy savings in the range of 20-40% have been reported with ternary feed mixtures. In addition to energy savings, such integrated units have also a potential for reduced capital cost, making them extra attractive. However, the industrial use has been limited, and difficulties in design and control have been reported as the main reasons. Minimum energy results have only been available for ternary feed mixtures and sharp product splits. This motivates further research in this area, and this thesis will hopefully give some contributions to better understanding of complex column systems. In the first part we derive the general analytic solution for minimum energy consumption in directly coupled columns for a multicomponent feed and any number of products. To our knowledge, this is a new contribution in the field. The basic assumptions are constant relative volatility, constant pressure and constant molar flows and the derivation is based on Underwood's classical methods. An important conclusion is that the minimum energy consumption in a complex directly integrated multi-product arrangement is the same as for the most difficult split between any pair of the specified products when we consider the performance of a conventional two-product column. We also present the Vmin-diagram, which is a simple graphical tool for visualisation of minimum energy related to feed distribution. The Vmin-diagram provides a simple mean to assess the detailed flow requirements for all parts of a complex directly coupled arrangement. The main purpose in

  16. Minimum Energy Requirements in Complex Distillation Arrangements

    Energy Technology Data Exchange (ETDEWEB)

    Halvorsen, Ivar J

    2001-07-01

    Distillation is the most widely used industrial separation technology and distillation units are responsible for a significant part of the total heat consumption in the world's process industry. In this work we focus on directly (fully thermally) coupled column arrangements for separation of multicomponent mixtures. These systems are also denoted Petlyuk arrangements, where a particular implementation is the dividing wall column. Energy savings in the range of 20-40% have been reported with ternary feed mixtures. In addition to energy savings, such integrated units have also a potential for reduced capital cost, making them extra attractive. However, the industrial use has been limited, and difficulties in design and control have been reported as the main reasons. Minimum energy results have only been available for ternary feed mixtures and sharp product splits. This motivates further research in this area, and this thesis will hopefully give some contributions to better understanding of complex column systems. In the first part we derive the general analytic solution for minimum energy consumption in directly coupled columns for a multicomponent feed and any number of products. To our knowledge, this is a new contribution in the field. The basic assumptions are constant relative volatility, constant pressure and constant molar flows and the derivation is based on Underwood's classical methods. An important conclusion is that the minimum energy consumption in a complex directly integrated multi-product arrangement is the same as for the most difficult split between any pair of the specified products when we consider the performance of a conventional two-product column. We also present the Vmin-diagram, which is a simple graphical tool for visualisation of minimum energy related to feed distribution. The Vmin-diagram provides a simple mean to assess the detailed flow requirements for all parts of a complex directly coupled arrangement. The main purpose in the first

  17. Novel investigation of the different Omni-direction-guide-vane angles effects on the urban vertical axis wind turbine output power via three-dimensional numerical simulation

    International Nuclear Information System (INIS)

    Shahizare, B.; Nik-Ghazali, N.; Chong, W.T.; Tabatabaeikia, S.; Izadyar, Nima; Esmaeilzadeh, Alireza

    2016-01-01

    Highlights: • Investigation of the Omni-direction-guide-vane impacts on the VAWT performance. • Obtain the best position of the guide vane angles in order to achieve the maximum performance. • Validation of the 3D computational fluid dynamics with experimental data. • Acquire the optimal Omni-direction-guide-vane based on numerical simulation results. - Abstract: The aim of this study is to present the effects of different Omni-direction-guide-vane (ODGV) angles on the performance of the vertical axis wind turbine (VAWT). For this purpose, five different straight-bladed VAWTs have been simulated via three-dimensional (3D) computational fluid dynamics (CFD). Hence, the VAWT without ODGV covering, were simulated and validated via CFD and experimental fluid dynamics (EFD) data, respectively in the first step. Indeed, grid and time step independency test as well as the effect of domain size, have been conducted and a suitable agreement was found based on comparison of the CFD and EFD results. In the next step, the VAWT was shrouded by ODGV cover and the whole system was simulated for 52 angles of the ODGV in four different tip speed ratios (TSR), to investigate the impact of guide vanes angles on the VAWT performance. Results of this study indicated that output power of the VAWT with α = 20° and β = 55° ODGV guide vanes, was improved 40.9%, 36.5%, 35.3% and 33.2%, respectively in four different TSR including 0.745, 1.091, 1.901 and 2.53.

  18. 3D computations of flow field in a guide vane blading designed by means of 2D model for a low head hydraulic turbine

    International Nuclear Information System (INIS)

    Krzemianowski, Z; Puzyrewski, R

    2014-01-01

    The paper presents the main parameters of the flow field behind the guide vane cascade designed by means of 2D inverse problem and following check by means of 3D commercial program ANSYS/Fluent applied for a direct problem. This approach of using different models reflects the contemporary design procedure for non-standardized turbomachinery stage. Depending on the model, the set of conservation equation to be solved differs, although the physical background remains the same. The example of computations for guide vane cascade for a low head hydraulic turbine is presented.

  19. Mass spectrometry by means of tandem accelerators

    International Nuclear Information System (INIS)

    Tuniz, C.

    1985-01-01

    Mass spectrometry based on an accelerator allows to measure rare cosmogenic isotopes found in natural samples with isotopic abundances up to 10E-15. The XTU Tandem of Legnaro National Laboratories can measure mean heavy isotopes (36Cl, 41Ca, 129I) in applications interesting cosmochronology and Medicine. The TTT-3 Tandem of the Naples University has been modified in view of precision studies of C14 in Archeology, Paleantology and Geology. In this paper a review is made of principles and methodologies and of some applicationy in the framework of the National Program for mass spectrametry research with the aid of accelerators

  20. Effects of Mie tip-vane on pressure distribution of rotor blade and power augmentation of horizontal axis wind turbine; Yokutan shoyoku Mie ben ni yoru suiheijiku fusha yokumenjo no atsuryoku bunpu no kaizen to seino kojo tono kankei

    Energy Technology Data Exchange (ETDEWEB)

    Shimizu, Y.; Maeda, T.; Kamada, Y. [Mie Univ., Mie (Japan); Seto, H. [Mitsubishi Motors Corp., Tokyo (Japan)

    2000-04-01

    By recent developments of exclusive rotor blade, the efficiency of wind turbine is improved substantially. By measuring pressure on rotor blades of horizontal axis wind turbines rotating in wind tunnels, this report clarified relation between improvement of pressure distribution on main rotor blades by Mie vane and upgrade of wind turbine performance. The results under mentioned have been got by measuring pressure distribution on rotor blades, visualization by tuft, and measuring resistance of Mie vane. (1) The difference of pressure between suction surface and pressure surface on the end of rotor blade increase, and output power of wind turbine improves. (2) Vortex of blade end is inhibited by Mie vane. (3) The reason of reduction on wind turbine performance with Mie vane in aria of high rotating speed ratio is the increase of Mie vane flow resistance.(NEDO)

  1. Influence of omni-directional guide vane on the performance of cross-flow rotor for urban wind energy

    Science.gov (United States)

    Wicaksono, Yoga Arob; Tjahjana, Dominicus Danardono Dwi Prija; Hadi, Syamsul

    2018-02-01

    Vertical axis wind turbine like cross-flow rotor have some advantage there are, high self-starting torque, low noise, and high stability; so, it can be installed in the urban area to produce electricity. But, the urban area has poor wind condition, so the cross-flow rotor needs a guide vane to increase its performance. The aim of this study is to determine experimentally the effect of Omni-Directional Guide Vane (ODGV) on the performance of a cross-flow wind turbine. Wind tunnel experiment has been carried out for various configurations. The ODGV was placed around the cross-flow rotor in order to increase ambient wind environment of the wind turbine. The maximum power coefficient is obtained as Cpmax = 0.125 at 60° wind direction. It was 21.46% higher compared to cross-flow wind turbine without ODGV. This result showed that the ODGV able to increase the performance of the cross-flow wind turbine.

  2. Investigating temporal patterns of a native bee community in a remnant North American bunchgrass prairie using blue vane traps.

    Science.gov (United States)

    Kimoto, Chiho; Debano, Sandra J; Thorp, Robbin W; Rao, Sujaya; Stephen, William P

    2012-01-01

    Native bees are important ecologically and economically because their role as pollinators fulfills a vital ecosystem service. Pollinators are declining due to various factors, including habitat degradation and destruction. Grasslands, an important habitat for native bees, are particularly vulnerable. One highly imperiled and understudied grassland type in the United States is the Pacific Northwest Bunchgrass Prairie. No studies have examined native bee communities in this prairie type. To fill this gap, the bee fauna of the Zumwalt Prairie, a large, relatively intact remnant of the Pacific Northwest Bunchgrass Prairie, was examined. Native bees were sampled during the summers of 2007 and 2008 in sixteen 40-ha study pastures on a plateau in northeastern Oregon, using a sampling method not previously used in grassland studies-blue vane traps. This grassland habitat contained an abundant and diverse community of native bees that experienced marked seasonal and inter-annual variation, which appears to be related to weather and plant phenology. Temporal variability evident over the entire study area was also reflected at the individual trap level, indicating a consistent response across the spatial scale of the study. These results demonstrate that temporal variability in bee communities can have important implications for long-term monitoring protocols. In addition, the blue vane trap method appears to be well-suited for studies of native bees in large expanses of grasslands or other open habitats, and may be a useful tool for monitoring native bee communities in these systems.

  3. Studi Eksperimen Aliran Melalui Square Duct dan Square Elbow 90º dengan Double Guide Vane pada Variasi Sudut Bukaan Damper

    Directory of Open Access Journals (Sweden)

    Andrew Jaya Nazar

    2017-01-01

    Full Text Available Instalasi saluran udara tidak hanya berupa pipa lurus, tetapi juga terdapat fitting/aksesoris perpipaan misalnya elbow 90o dan damper. Aksesoris perpipaan ini berfungsi agar saluran udara dapat terpasang sesuai dengan kebutuhan. Namun, penggunaan aksesoris perpipaan ini menyebabkan bertambahnya pressure drop akibat adanya friction loss dan separation loss. Pemasangan guide vane pada elbow 90o diharapkan dapat mengurangi pressure drop karena dapat mengurangi terjadinya secondary flow, namun hal ini dapat menambah kerugian akibat gaya gesek. Saat ini penghematan energi menjadi sorotan terutama dalam dunia industri. Penurunan pressure drop pada belokan perpipaan sangat diharapkan, agar dapat menghemat energi lebih. Untuk itu perlu dilakukan usaha agar dapat menurunkan pressure drop yang terjadi. Penelitian ini dilakukan secara eksperimen dengan benda uji saluran udara yang terdiri dari: upstream duct (straight duct, square elbow 90o dengan r/Dh=1,5 dan dilengkapi double guide vane, damper, downstream duct (straight duct, dan induced fan. Pengukuran parameter yang dibutuhkan dilakukan dengan menggunakan: pitot tube, inclined manometer, pressure tranducer. Dari eksperimen ini diperoleh bahwa profil kecepatan pada masing-masing variasi sudut bukaan damper sudah mendekati keadaan recovery aliran pada akhir section baik dari bidang vertikal maupun horizontal. Pressure drop yang terjadi semakin naik seiring dengan bertambahnya nilai bilangan Reynolds dan sudut bukaan damper. Nilai konstanta damper semakin naik dari bukaan sudut 0o hingga 30o.

  4. Computational Fluid Dynamics (CFD) Analyses in Support of Space Shuttle Main Engine (SSME) Heat Exchanger (HX) Vane Cracking Investigation

    Science.gov (United States)

    Garcia, Roberto; Benjamin, Theodore G.; Cornelison, J.; Fredmonski, A. J.

    1993-01-01

    Integration issues involved with installing the alternate turbopump (ATP) High Pressure Oxygen Turbopump (HPOTP) into the SSME have raised questions regarding the flow in the HPOTP turnaround duct (TAD). Steady-state Navier-Stokes CFD analyses have been performed by NASA and Pratt & Whitney (P&W) to address these questions. The analyses have consisted of two-dimensional axisymmetric calculations done at Marshall Space Flight Center and three-dimensional calculations performed at P&W. These analyses have identified flowfield differences between the baseline ATP and the Rocketdyne configurations. The results show that the baseline ATP configuration represents a more severe environment to the inner HX guide vane. This vane has limited life when tested in conjunction with the ATP but infinite life when tested with the current SSME HPOTP. The CFD results have helped interpret test results and have been used to assess proposed redesigns. This paper includes details of the axisymmetric model, its results, and its contribution towards resolving the problem.

  5. Numerical Study of the Effects of Thermal Barrier Coating and Turbulence Intensity on Cooling Performances of a Nozzle Guide Vane

    Directory of Open Access Journals (Sweden)

    Prasert Prapamonthon

    2017-03-01

    Full Text Available This work presents a numerical investigation of the combined effects of thermal barrier coating (TBC with mainstream turbulence intensity (Tu on a modified vane of the real film-cooled nozzle guide vane (NGV reported by Timko (NASA CR-168289. Using a 3D conjugate heat transfer (CHT analysis, the NGVs with and without TBC are simulated at three Tus (Tu = 3.3%, 10% and 20%. The overall cooling effectiveness, TBC effectiveness and heat transfer coefficient are analyzed and discussed. The results indicate the following three interesting phenomena: (1 TBC on the pressure side (PS is more effective than that on the suction side (SS due to a fewer number of film holes on the SS; (2 for all three Tus, the variation trends of the overall cooling effectiveness are similar, and TBC plays the positive and negative roles in heat flux at the same time, and significantly increases the overall cooling effectiveness in regions cooled ineffectively by cooling air; (3 when Tu increases, the TBC effect is more significant, for example, at the highest Tu (Tu = 20% the overall cooling effectiveness can increase as much as 24% in the film cooling ineffective regions, but near the trailing edge (TE and the exits and downstream of film holes on the SS, this phenomenon is slight.

  6. Specificity and autoregulation of Notch binding by tandem WW domains in suppressor of Deltex.

    Science.gov (United States)

    Jennings, Martin D; Blankley, Richard T; Baron, Martin; Golovanov, Alexander P; Avis, Johanna M

    2007-09-28

    WW domains target proline-tyrosine (PY) motifs and frequently function as tandem pairs. When studied in isolation, single WW domains are notably promiscuous and regulatory mechanisms are undoubtedly required to ensure selective interactions. Here, we show that the fourth WW domain (WW4) of Suppressor of Deltex, a modular Nedd4-like protein that down-regulates the Notch receptor, is the primary mediator of a direct interaction with a Notch-PY motif. A natural Trp to Phe substitution in WW4 reduces its affinity for general PY sequences and enhances selective interaction with the Notch-PY motif via compensatory specificity-determining interactions with PY-flanking residues. When WW4 is paired with WW3, domain-domain association, impeding proper folding, competes with Notch-PY binding to WW4. This novel mode of autoinhibition is relieved by binding of another ligand to WW3. Such cooperativity may facilitate the transient regulatory interactions observed in vivo between Su(dx) and Notch in the endocytic pathway. The highly conserved tandem arrangement of WW domains in Nedd4 proteins, and similar arrangements in more diverse proteins, suggests domain-domain communication may be integral to regulation of their associated cellular activities.

  7. Bands and chromosome arrangement in interphase nuclei

    International Nuclear Information System (INIS)

    Bianchi, N.O.; Bianchi, M.A.; Matayoshi, T.

    1977-01-01

    Chromosomes from the vole mouse Akodon dolores and from laboratory mouse showed the presence of G-bands after 3 minutes digestion with trypsin and Giemsa stain. Simultaneously, 30- to 40% of the interphase nuclei exhibited a dark ring parallel to the nuclear contour and a radial array of the chromatin in the internal and external regions of the ring. The origin and meaning of this ring image was analyzed by combining progressive trypsinizations with other methods such as C-banding procedures, autoradiography with 3 HTdR, staining with quinacrine mustard and 33258 Hoechst fluorochromes. Moreover, the presence of the dark ring was also investigated in cells treated with actinomycin and in control cells not subjected to any treatment. The results obtained allowed to assume that in interphase nuclei the chromosomes have chromatin bridges which connect the dark G-bands and that these bridges are probably involved in maintaining an ordered architecture of the nucleus with fixed chromosome positions in regard to the nuclear envelope and in regard to other chromosomes. Trypsinization produces a disruption of the interphase chromatin arrangement and the subsequent appearance of a dark ring formed by the combination of constitutive heterochromatin and dark G-bands. (auth.)

  8. Process arrangement options for Defense waste immobilization

    International Nuclear Information System (INIS)

    1980-02-01

    Current plans are to immobilize the SRP high-level liquid wastes in a high integrity form. Borosilicate glass was selected in 1977 as the reference waste form and a mjaor effort is currently underway to develop the required technology. A large new facility, referred to as the Defense Waste Processing Facility (DWPF) is being designed to carry out this mission, with project authorization targeted for 1982 and plant startup in 1989. However, a number of other process arrangements or manufacturing strategies, including staging the major elements of the project or using existing SRP facilities for some functions, have been suggested in lieu of building the reference DWPF. This study assesses these various options and compares them on a technical and cost basis with the DWPF. Eleven different manufacturing options for SRP defense waste solidification were examined in detail. These cases are: (1) vitrification of acid waste at current generation rate; (2) vitrification of current rate acid waste and caustic sludge; (3 and 4) vitrification of the sludge portion of neutralized waste; (5) decontamination of salt cake and storage of concentrated cesium and strontium for later immobilization; (6) processing waste in a facility with lower capacity than the DWPF; (7) processing waste in a combination of existing and new facilities; (8) waste immobilization in H Canyon; (9) vitrification of both sludge and salt; (10) DWPF with onsite storage; (11) deferred authorization of DWPF

  9. Contractual arrangements for uranium exploration and mining

    International Nuclear Information System (INIS)

    1988-07-01

    Uranium exploration in WOCA, stabilized since 1985 at a level of annual expenditures of US $120-150 million. About half of this amount is funded by mining companies based in the uranium consumer countries such as the Federal Republic of Germany, France, the Republic of Korea, Japan, United Kingdom etc. and expended outside their home countries, mainly in Australia, Canada and USA, but also in a number of African countries. As WOCA's uranium production is concentrated in a few countries, in 1986, Australia, Canada, South Africa and USA had a combined share of nearly 70% of the total, a stronger diversification of uranium supplies may be desirable in the future. This expected trend may result in the planning or uranium exploration projects by international uranium companies in countries in Africa, Asia and South America. To provide information which can be helpful for both parties in the negotiations of cooperation agreement is the scope of this document. It contains a brief introductory part including an overview of the development of the different forms of international cooperation, a case history provided by Zambia, a report listing the essential subjects to be included in an uranium agreement as well as an example of a structure of contractual arrangements. This part is followed by an extensive annex with three ''no-names-no numbers'' contract texts, which were concluded in the later part of the 1970s and beginning of the 1980s

  10. Strike a balance with flexible working arrangements

    Energy Technology Data Exchange (ETDEWEB)

    Madison, Alison L.

    2012-12-15

    Monthly Economic Diversity column for the Tri-City Herald - Topic: Telworking - Excerpt below: As the holiday season kicks into high gear, work-life balance is on many of our minds. How can I meet all of my work commitments this month when no one will be in the office, and still strategically use very little vacation time to stretch the holiday break from four days to fourteen? Am I right? I think most all of us want to stay engaged with our professional lives while maintaining the freedom to prioritize our personal lives. And many employers have come up with ways to help us achieve that balance. Teleworking is not a brand new concept, but is certainly gaining steam as employers and employees alike try to find ways to meet a variety of wants and needs. There are benefits to both sides when it comes to offering flexible working arrangements such as teleworking. For businesses attempting to meet sustainability targets by reducing employee commuting and associated impacts to energy and environment, the benefits of this option can really add up.

  11. Thirty years of physics at the Bucharest tandem accelerator

    International Nuclear Information System (INIS)

    Dobrescu, S.; Marinescu, L.; Dumitru, G.; Cata-Danil, Gh.

    2003-01-01

    The main parameters of the Bucharest tandem accelerator, as well as the main milestones of its history since March 1973 when it was commissioned are shortly presented. A general presentation of the main basic and applied physics research so far undertaken at the tandem is given, ending with some ideas related with the future perspectives of the tandem. (authors)

  12. STATIONARY DISTRIBUTION OF A TANDEM QUEUE WITH ADDITIONAL FLOWS ON THE STATIONS OF THE TANDEM

    Directory of Open Access Journals (Sweden)

    V. I. Klimenok

    2017-01-01

    Full Text Available A tandem queueing system consisting of a finite number of multi-server stations without buffers is analized. The input flow at the first station is a ???????????? (Markovian arrival process. The customers from this flow aim to be served at all stations of the tandem. For any station, besides transit customers proceeding from the previous station, an additional ???????????? flow of new customers arrives at this station directly. Customers from this flow aim to be served at this station and all subsequent stations of the tandem. The service times of customer at the stations are exponentially distributed with the service rate depending of number of the station. The algorithms for culculation of stationary distributions and the loss probabilities associated with the tandem are given.

  13. A tandem queue with delayed server release

    NARCIS (Netherlands)

    Nawijn, W.M.

    1997-01-01

    We consider a tandem queue with two stations. The rst station is an s-server queue with Poisson arrivals and exponential service times. After terminating his service in the rst station, a customer enters the second station to require service at an exponential single server, while in the meantime he

  14. The PSI/ETH tandem accelerator facility

    Energy Technology Data Exchange (ETDEWEB)

    Synal, H.A.; Doebeli, M.; Fuhrmann, H.; Kubik, P.W.; Nebiker, P.W. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)] [and others

    1997-09-01

    The 1996 operation of the PSI/ETH tandem accelerator at ETH Hoenggerberg is summarised with a detailed compilation of the beam time statistics and the statistics of AMS samples for the different radioisotopes and for the major fields of research. (author) 2 tab.

  15. Optimal dispatching in a tandem queue

    NARCIS (Netherlands)

    van Leeuwen, D.; Núñez Queija, R.

    2017-01-01

    We investigate a Markovian tandem queueing model in which service to the first queue is provided in batches. The main goal is to choose the batch sizes so as to minimize a linear cost function of the mean queue lengths. This model can be formulated as a Markov Decision Process (MDP) for which the

  16. Edge diagnostics for tandem mirror machines

    International Nuclear Information System (INIS)

    Allen, S.L.

    1984-01-01

    The edge plasma in a tandem mirror machine shields the plasma core from cold neutral gas and impurities. A variety of diagnostics are used to measure the fueling, shielding, and confinement of the edge plasma in both the end plug and central cell regions. Fast ion gauges and residual gas analyzers measure the gas pressure and composition outside of the plasma. An array of Langmuir probes is used to measure the electron density and temperature. Extreme ultraviolet (euv) and visible spectroscopy are used to measure both the impurity and deuterium densities and to estimate the shielding factor for the core plasma. The linear geometry of a tandem mirror also allows direct measurements of the edge plasma by sampling the ions and electrons lost but the ends of the machine. Representative data obtained by these diagnostics during operation of the Tandem Mirror Experiment (TMX) and Tandem Mirror Experiment-Upgrade (TMX-U) experiments are presented. Diagnostics that are currently being developed to diagnose the edge plasma are also discussed

  17. Tandem queue with server slow-down

    NARCIS (Netherlands)

    Miretskiy, D.I.; Scheinhardt, W.R.W.; Mandjes, M.R.H.

    2007-01-01

    We study how rare events happen in the standard two-node tandem Jackson queue and in a generalization, the socalled slow-down network, see [2]. In the latter model the service rate of the first server depends on the number of jobs in the second queue: the first server slows down if the amount of

  18. 25 MV tandem accelerator at Oak Ridge

    International Nuclear Information System (INIS)

    Jones, C.M.

    1980-01-01

    A new heavy-ion accelerator facility is under construction at the Oak Ridge National Laboratory. A brief description of the scope and status of this project is presented with emphasis on the first operational experience with the 25 MV tandem accelerator

  19. Modelling of tandem cell temperature coefficients

    Energy Technology Data Exchange (ETDEWEB)

    Friedman, D.J. [National Renewable Energy Lab., Golden, CO (United States)

    1996-05-01

    This paper discusses the temperature dependence of the basic solar-cell operating parameters for a GaInP/GaAs series-connected two-terminal tandem cell. The effects of series resistance and of different incident solar spectra are also discussed.

  20. Tandem mirror next step conceptual design

    International Nuclear Information System (INIS)

    Doggett, J.N.; Damm, C.C.; Bulmer, R.H.

    1980-01-01

    A study was made to define the features of the experimental mirror fusion device - The Tandem Mirror Next Step, or TMNS - that will bridge the gap between present mirror confinement experiments and a power-producing reactor. We outline the project goals, describe some initial device parameters, and relate the technological requirements to ongoing development programs

  1. Quality evaluation of tandem mass spectral libraries.

    Science.gov (United States)

    Oberacher, Herbert; Weinmann, Wolfgang; Dresen, Sebastian

    2011-06-01

    Tandem mass spectral libraries are gaining more and more importance for the identification of unknowns in different fields of research, including metabolomics, forensics, toxicology, and environmental analysis. Particularly, the recent invention of reliable, robust, and transferable libraries has increased the general acceptance of these tools. Herein, we report on results obtained from thorough evaluation of the match reliabilities of two tandem mass spectral libraries: the MSforID library established by the Oberacher group in Innsbruck and the Weinmann library established by the Weinmann group in Freiburg. Three different experiments were performed: (1) Spectra of the libraries were searched against their corresponding library after excluding either this single compound-specific spectrum or all compound-specific spectra prior to searching; (2) the libraries were searched against each other using either library as reference set or sample set; (3) spectra acquired on different mass spectrometric instruments were matched to both libraries. Almost 13,000 tandem mass spectra were included in this study. The MSforID search algorithm was used for spectral matching. Statistical evaluation of the library search results revealed that principally both libraries enable the sensitive and specific identification of compounds. Due to higher mass accuracy of the QqTOF compared with the QTrap instrument, matches to the MSforID library were more reliable when comparing spectra with both libraries. Furthermore, only the MSforID library was shown to be efficiently transferable to different kinds of tandem mass spectrometers, including "tandem-in-time" instruments; this is due to the coverage of a large range of different collision energy settings-including the very low range-which is an outstanding characteristics of the MSforID library.

  2. Optical properties of quasiperiodically arranged semiconductor nanostructures

    Energy Technology Data Exchange (ETDEWEB)

    Werchner, Marco

    2009-12-18

    This work consists of two parts which are entitled ''One-Dimensional Resonant Fibonacci Quasicrystals'' and ''Resonant Tunneling of Light in Silicon Nanostructures''. A microscopic theory has been applied to investigate the optical properties of the respective semiconductor nanostructures. The studied one-dimensional resonant Fibonacci quasicrystals consist of GaAs quantum wells (QW) that are separated by either a large spacer L or a small one S. These spacers are arranged according to the Fibonacci sequence LSLLSLSL.. The average spacing satisfies a generalized Bragg condition with respect to the 1s-exciton resonance of the QWs. A theory, that makes use of the transfer-matrix method and that allows for the microscopic description of many-body effects such as excitation-induced dephasing caused by the Coulomb scattering of carriers, has been applied to compute the optical spectra of such structures. A pronounced sharp reflectivity minimum is found in the vicinity of the heavy-hole resonance both in the measured as well as in the calculated linear 54-QW spectra. Specifically, the influence of the carrier density, of the QW arrangement, of a detuning away from the exact Bragg condition, of the average spacing as well as of the ratio of the optical path lengths of the large and small spacers L and S, respectively, and of the QW number on the optical properties of the samples have been studied. Additionally, self-similarity among reflection spectra corresponding to different QW numbers that exceed a Fibonacci number by one is observed, which identifies certain spectral features as true fingerprints of the Fibonacci spacing. In the second part, resonant tunneling of light in stacked structures consisting of alternating parallel layers of silicon and air have been studied theoretically.Light may tunnel through the air barrier due to the existence of evanescent waves inside the air layers if the neighboring silicon layer is close

  3. Human Rights Arrangement on Indonesian Law

    Directory of Open Access Journals (Sweden)

    S. Masribut Sardol

    2014-01-01

    Full Text Available Article 1 paragraph (3 of the Constitution of 1945 (UUD 1945 stated that Indonesia is a Rule of Law. One feature of the Rule of Law is the existence of human rights in the state administration. Indonesia, since independence on August 17, 1945 has asserted the defense of human rights as stated in the opening clause and in the torso of the 1945 Constitution Article 27-34. In the era of reform, on the Government of President Habibie, the President and the Parliament ratified the UN convention against torture and other cruel, inhuman, or degrading human dignity into Law number 5 of 1998. Then the MPR also publishes the statutes of MPR No. XVII/MPR/1998 on Human Rights, which was followed up with the appearance of Law No. 39 of 1999 on human rights. In accordance with the law in Indonesia based on the sort of Law No. 12 of 2011, the actual products that have been issued by the Government (the MPR, DPR and President that follow up the substance of Human Rights in the Constitution with established Assembly and the law is already correct. But when the MPR then does the second amendment to the Constitution on August 18, 2000 by adding a special article chapters and contains about Human Rights (as mentioned in Chapter X-A section 28 A-J, have made the complexity hierarchy of law in Indonesia because it is not in accordance with the substance of article 7 of Law No. 12 of 2011. How To Cite: Sardol, S. (2014. Human Rights Arrangement on Indonesian Law. Rechtsidee, 1(1, 85-100. doi:http://dx.doi.org/10.21070/jihr.v1i1.105

  4. Institutional arrangements for a multinational reprocessing plant

    International Nuclear Information System (INIS)

    Smith, C.B.; Chayes, A.

    1977-01-01

    The paper lists some of the major issues that would have to be faced in negotiating the institutional structure of a multinational nuclear-fuel center. None of the organization problems is inherently insoluble. Difficulties are exacerbated by the large number of questions, their interrelations, and the complexity of the assumed structure. However, the assumptions posed the most difficult case. A reduction in membership and in the ambitious scope of the enterprise, at least at the outset, would greatly reduce the complexity of the organizational structure and the difficulty of negotiations. The analysis suggests that multinational fuel-cycle activities should start out more modestly, perhaps only with joint appraisal by a relatively few countries with existing geographic or economic connections. If operations are contemplated it would seem that the first step should be joint arrangements for spent-fuel storage, with the decision to go forward to more elaborate activities deferred. This approach would not only be simpler and permit the parties to gain experience working together, but it would have the virtue of delaying reprocessing until it was clear that there was a real need for it. Even on this reduced basis, the negotiating task would not be easy. The key, of course, to overcoming difficult technical problems of institutional structure is politial will--the genuine commitment of the participants to the aims and values of the enterprise. This suggests that any effort to cajole--not to say coerce--participation in a multinational fuel-cycle enterprise would be wholly misplaced. A reluctant partner would have available an infinitude of points and issues to create plausible, irritating, and ultimately defeating delay and complication in the negotiating process. Only assent freely given in the perception that the enterprise really serves the interest of the countries involved will be able to surmount the many institutional problems that will inevitably arise

  5. 3D shape optimization of fan vanes for multiple operating regimes subject to efficiency and noise-related excellence criteria and constraints

    Directory of Open Access Journals (Sweden)

    Ivo Marinić-Kragić

    2016-01-01

    Full Text Available Fully generic 3D shapes of centrifugal roof fan vanes are explored based on a custom-developed numerical workflow with the ability to vary the vane 3D shape by manipulating the control points of parametric surfaces and change the number of vanes and rotation speed. An excellence formulation is based on design flow efficiency, multi-regime operational conditions and noise criteria for various cases, including multi-objective optimization. Multiple cases of optimization demonstrate the suitability of customized and individualized fan designs for specific working environments according to the selected excellence criteria. Noise analysis is considered as an additional decision-making tool for cases where multiple solutions of equal efficiency are generated and as an additional criteria for multi-objective optimization. The 3D vane shape enables further gains in efficiency compared to 2D shape optimization, while multi-objective optimization with noise as an additional criterion shows potential to greatly reduce the roof fan noise with only small losses in efficiency. The developed workflow which comprises (i a 3D parametric shape modeler, (ii an evolutionary optimizer and (iii a computational fluid dynamics (CFD simulator can be viewed as an integral tool for optimizing the designs of roof fans under custom conditions.

  6. Achieving more efficient operation of the nozzle vane and rotor blade rows of gas turbines through using nonaxisymmetric end wall surfaces of interblade channels

    Science.gov (United States)

    Inozemtsev, A. A.; Samokhvalov, N. Yu.; Tikhonov, A. S.

    2012-09-01

    Results from a numerical study of three versions of the end-wall generatrix of the interblade channel used in the second-stage nozzle vanes of a prospective engine's turbine are presented. Recommendations for designing nonaxisymmetric end-wall surfaces are suggested based on the obtained data.

  7. Effect of turbulence intensity on cross-injection film cooling at a stepped or smooth endwall of a gas turbine vane passage.

    Science.gov (United States)

    Wu, Pey-Shey; Tsai, Shen-Ta; Jhuo, Yue-Hua

    2014-01-01

    This study is concerned with a film cooling technique applicable to the protection of the endwalls of a gas turbine vane. In the experiments, cross-injection coolant flow from two-row, paired, inclined holes with nonintersecting centerlines was utilized. The test model is a scaled two-half vane. The levels of turbulence intensity used in the experiments are T.I. = 1.8%, 7%, and 12%. Other parameters considered in the film cooling experiments include three inlet Reynolds numbers (9.20 × 10(4), 1.24 × 10(5), and 1.50 × 10(5)), three blowing ratios (0.5, 1.0, and 2.0), and three endwall conditions (smooth endwall and stepped endwall with forward-facing or backward-facing step). Thermochromic liquid crystal (TLC) technique with steady-state heat transfer experiments was used to obtain the whole-field film cooling effectiveness. Results show that, at low turbulence intensity, increasing Reynolds number decreases the effectiveness in most of the vane passage. There is no monotonic trend of influence by Reynolds number at high turbulence intensity. The effect of blowing ratio on the effectiveness has opposite trends at low and high turbulence levels. Increasing turbulent intensity decreases the effectiveness, especially near the inlet of the vane passage. With a stepped endwall, turbulence intensity has only mild effect on the film cooling effectiveness.

  8. Effect of Turbulence Intensity on Cross-Injection Film Cooling at a Stepped or Smooth Endwall of a Gas Turbine Vane Passage

    Directory of Open Access Journals (Sweden)

    Pey-Shey Wu

    2014-01-01

    Full Text Available This study is concerned with a film cooling technique applicable to the protection of the endwalls of a gas turbine vane. In the experiments, cross-injection coolant flow from two-row, paired, inclined holes with nonintersecting centerlines was utilized. The test model is a scaled two-half vane. The levels of turbulence intensity used in the experiments are T.I.=1.8%, 7%, and 12%. Other parameters considered in the film cooling experiments include three inlet Reynolds numbers (9.20×104 , 1.24×105, and  1.50×105, three blowing ratios (0.5, 1.0, and 2.0, and three endwall conditions (smooth endwall and stepped endwall with forward-facing or backward-facing step. Thermochromic liquid crystal (TLC technique with steady-state heat transfer experiments was used to obtain the whole-field film cooling effectiveness. Results show that, at low turbulence intensity, increasing Reynolds number decreases the effectiveness in most of the vane passage. There is no monotonic trend of influence by Reynolds number at high turbulence intensity. The effect of blowing ratio on the effectiveness has opposite trends at low and high turbulence levels. Increasing turbulent intensity decreases the effectiveness, especially near the inlet of the vane passage. With a stepped endwall, turbulence intensity has only mild effect on the film cooling effectiveness.

  9. Support mechanism for a mirrored surface or other arrangement

    Science.gov (United States)

    Cutburth, Ronald W.

    1987-01-01

    An adjustment mechanism such as a three point spherical mount for adjustably supporting a planer mirror or other type of arrangement relative to a plane defined by a given pair of intersecting perpendicular axes is disclosed herein. This mechanism includes first means for fixedly supporting the mirror or other arrangement such that the latter is positionable within the plane defined by the given pair of intersecting perpendicular axes. This latter means and the mirror or other such arrangement are supported by second means for limited movement back and forth about either of the intersecting axes. Moreover, this second means supports the first means and the mirror or other arrangement such that the latter is not movable in any other way whereby the point on the mirror or other arrangement coinciding with the intersection of the given axes does not move or float, thereby making the ability to adjust the mirror or other such arrangement more precise and accurate.

  10. Concepts for institutional arrangements for the nuclear fuel cycle

    International Nuclear Information System (INIS)

    1979-01-01

    The paper focuses on the role of institutional arrangements in developing a consensus in international nuclear cooperation. Institutional arrangements are defined as undertakings and activities by governments or private entities to facilitate the efficient and secure functioning of the nuclear fuel cycle. The first two sections of the paper explore the historical role of cooperative arrangements, suggest criteria for evaluating the usefulness of institutional arrangements, and review the status of the discussion of institutional arrangements in INFCE Working Groups as of December 1978. The final section of the paper, explores potential relationships between various institutional arrangements and suggests that certain areas such as, the standardization of nuclear practices, joint commercial and development undertakings, nuclear supply assurances, and the settlement of disputes may have broad application for several stages of the fuel cycle and merit further study

  11. Electricity generation sectors under purchase obligation: support arrangement analysis

    International Nuclear Information System (INIS)

    2013-04-01

    This report aims at assessing the operation of the support arrangement by which currently benefit some electricity production sectors in France (renewable energies, co-generation) with respect to the evolution of the energy mix within the frame of energy transition. Other support arrangements presently adopted in Europe are also addressed as lessons to be learned. Criteria are established for any support arrangement. The report presents the French and European context regarding such support arrangement with purchasing obligation, and addresses the future evolutions of the European Commission. It highlights challenges for the electric system and for the energy market (impact on investments, optimization of market operation), describes and assesses the French purchasing obligation arrangement, and describes and assesses other existing support arrangements

  12. In situ detection of tandem DNA repeat length

    Energy Technology Data Exchange (ETDEWEB)

    Yaar, R.; Szafranski, P.; Cantor, C.R.; Smith, C.L. [Boston Univ., MA (United States)

    1996-11-01

    A simple method for scoring short tandem DNA repeats is presented. An oligonucleotide target, containing tandem repeats embedded in a unique sequence, was hybridized to a set of complementary probes, containing tandem repeats of known lengths. Single-stranded loop structures formed on duplexes containing a mismatched (different) number of tandem repeats. No loop structure formed on duplexes containing a matched (identical) number of tandem repeats. The matched and mismatched loop structures were enzymatically distinguished and differentially labeled by treatment with S1 nuclease and the Klenow fragment of DNA polymerase. 7 refs., 4 figs.

  13. Baffle-former arrangement for nuclear reactor vessel internals

    International Nuclear Information System (INIS)

    Machado, O.J.; Berringer, R.T.

    1978-01-01

    A baffle-former arrangement for the reactor vessel internals of a nuclear reactor is described. The arrangement includes positioning of formers at the same elevations as the fuel assembly grids, and positioning flow holes in the baffle plates directly beneath selected former grid elevations. The arrangement reduces detrimental cross flows, maintains proper core barrel and baffle temperatures, and alleviates the potential of overpressurization within the baffle-former assembly under assumed major accident conditions

  14. Optimal support arrangement of piping systems using genetic algorithm

    International Nuclear Information System (INIS)

    Chiba, T.; Okado, S.; Fujii, I.; Itami, K.

    1996-01-01

    The support arrangement is one of the important factors in the design of piping systems. Much time is required to decide the arrangement of the supports. The authors applied a genetic algorithm to find the optimum support arrangement for piping systems. Examples are provided to illustrate the effectiveness of the genetic algorithm. Good results are obtained when applying the genetic algorithm to the actual designing of the piping system

  15. Ulysses arrangements in psychiatry: a matter of good care?

    Science.gov (United States)

    Gremmen, I; Widdershoven, G; Beekman, A; Zuijderhoudt, R; Sevenhuijsen, S

    2008-02-01

    This article concerns the issue of how an ethic of care perspective may contribute to both normative theory and mental health care policy discussions on so called Ulysses arrangements, a special type of advance directives in psychiatry. The debate on Ulysses arrangements has predominantly been waged in terms of autonomy conceived of as the right to non-intervention. On the basis of our empirical investigations into the experiences of persons directly involved with Ulysses arrangements, we argue that a care ethics perspective may broaden and deepen the debate on Ulysses arrangements, by introducing additional concepts, such as vulnerability, responsibility and mutuality, and by refining familiar concepts, such as autonomy.

  16. Spiral phyllotaxis underlies constrained variation in Anemone (Ranunculaceae) tepal arrangement.

    Science.gov (United States)

    Kitazawa, Miho S; Fujimoto, Koichi

    2018-05-01

    Stabilization and variation of floral structures are indispensable for plant reproduction and evolution; however, the developmental mechanism regulating their structural robustness is largely unknown. To investigate this mechanism, we examined positional arrangement (aestivation) of excessively produced perianth organs (tepals) of six- and seven-tepaled (lobed) flowers in six Anemone species (Ranunculaceae). We found that the tepal arrangement that occurred in nature varied intraspecifically between spiral and whorled arrangements. Moreover, among the studied species, variation was commonly limited to three types, including whorls, despite five geometrically possible arrangements in six-tepaled flowers and two types among six possibilities in seven-tepaled flowers. A spiral arrangement, on the other hand, was unique to five-tepaled flowers. A spiral phyllotaxis model with stochasticity on initiating excessive primordia accounted for these limited variations in arrangement in cases when the divergence angle between preexisting primordia was less than 144°. Moreover, interspecific differences in the frequency of the observed arrangements were explained by the change of model parameters that represent meristematic growth and differential organ growth. These findings suggest that the phyllotaxis parameters are responsible for not only intraspecific stability but interspecific difference of floral structure. Decreasing arrangements from six-tepaled to seven-tepaled Anemone flowers demonstrate that the stabilization occurs as development proceeds to increase the component (organ) number, in contrast from the intuition that the variation will be larger due to increasing number of possible states (arrangements).

  17. Numerical investigation on pressure fluctuations in centrifugal compressor with different inlet guide vanes pre-whirl angles

    Science.gov (United States)

    Wang, Y. C.; Shi, M.; Cao, S. L.; Li, Z. H.

    2013-12-01

    The pressure fluctuations in a centrifugal compressor with different inlet guide vanes (IGV) pre-whirl angles were investigated numerically, as well as the pre-stress model and static structural of blade. The natural frequency was evaluated by pre-stress model analysis. The results show that, the aero-dynamic pressure acting on blade surface is smaller than rotation pre-stress, which wouldn't result in large deformation of blade. The natural frequencies with rotation pre-stress are slightly higher than without rotation pre-stress. The leading mechanism of pressure fluctuations for normal conditions is the rotor-stator (IGVs) interaction, while is serious flow separations for conditions that are close to surge line. A few frequency components in spectra are close to natural frequency, which possibly result in resonant vibration if amplitude is large enough, which is dangerous for compressor working, and should be avoided.

  18. Numerical investigation on pressure fluctuations in centrifugal compressor with different inlet guide vanes pre-whirl angles

    International Nuclear Information System (INIS)

    Wang, Y C; Shi, M; Cao, S L; Li, Z H

    2013-01-01

    The pressure fluctuations in a centrifugal compressor with different inlet guide vanes (IGV) pre-whirl angles were investigated numerically, as well as the pre-stress model and static structural of blade. The natural frequency was evaluated by pre-stress model analysis. The results show that, the aero-dynamic pressure acting on blade surface is smaller than rotation pre-stress, which wouldn't result in large deformation of blade. The natural frequencies with rotation pre-stress are slightly higher than without rotation pre-stress. The leading mechanism of pressure fluctuations for normal conditions is the rotor-stator (IGVs) interaction, while is serious flow separations for conditions that are close to surge line. A few frequency components in spectra are close to natural frequency, which possibly result in resonant vibration if amplitude is large enough, which is dangerous for compressor working, and should be avoided

  19. Current results of the tandem mirror experiment

    International Nuclear Information System (INIS)

    Drake, R.P.

    1980-01-01

    The basic operating characteristics of the Tandem Mirror Experiment, (TMX) at the Lawrence Livermore Laboratory in the USA have been established. Tandem-mirror plasmas have been produced using neutral-beam-fueled end plugs and a gas-fueled center cell. An axial potential well between the end plugs has been measured. There is direct evidence that this potential well enhances the axial confinement of the center-cell ions. The observed densities and loss currents are consistent with preliminary studies of the particle sources and losses near the magnetic axis. The observed confinement is consistent with theory when plasma fluctuations are low. When the requirement of drift-cyclotron loss-cone mode stability is violated, the plasma fluctuations degrade the center-cell confinement

  20. Operation of the tandem-linac accelerator

    International Nuclear Information System (INIS)

    Anon.

    1985-01-01

    The tandem-linac accelerator system is operated as a source of energetic heavy-ion projectiles for research in several areas of nuclear physics and occasionally in other areas of science. The accelerator system consists of a 9-MV tandem electrostatic accelerator and a superconducting-linac energy booster that can provide an additional 20 MV of acceleration. A figure shows the layout of this system, which will be operated in its present form until September 1985, when it will be incorporated into the larger ATLAS system. In both the present and future forms the accelerator is designed to provide the exceptional beam quality and overall versatility required for precision nuclear-structure research

  1. Moment approach to tandem mirror radial transport

    International Nuclear Information System (INIS)

    Siebert, K.D.; Callen, J.D.

    1986-02-01

    A moment approach is proposed for the study of tandem mirror radial transport in the resonant plateau regime. The salient features of the method are described with reference to axisymmetric tokamak transport theory. In particular, the importance of momentum conservation to the establishment of the azimuthal variations in the electrostatic potential is demonstrated. Also, an ad hoc drift kinetic equation is solved to determine parallel viscosity coefficients which are required to close the moment system

  2. Designs of tandem-mirror fusion reactors

    International Nuclear Information System (INIS)

    Carlson, G.A.; Barr, W.L.; Boghosian, B.M.

    1981-01-01

    We have completed a comparative evaluation of several end plug configurations for tandem mirror fusion reactors with thermal barriers. The axi-cell configuration has been selected for further study and will be the basis for a detailed conceptual design study to be carried out over the next two years. The axi-cell end plug has a simple mirror cell produced by two circular coils followed by a transition coil and a yin-yang pair, which provides for MHD stability

  3. Tandem mirror next step: remote maintenance

    International Nuclear Information System (INIS)

    Doggett, J.N.; Damm, C.C.; Hanson, C.L.

    1980-01-01

    This study of the next proposed experiment in the Mirror Fusion Program, the Tandem Mirror Next Step (TMNS), has included serious consideration of the maintenance requirements of such a large source of high energy neutrons with its attendant throughput of tritium. Although maintenance will be costly in time and money, our conclusion is that with careful attention to a design for maintenance plan such a device can be reliably operated

  4. Cold Climate Heat Pumps Using Tandem Compressors

    Energy Technology Data Exchange (ETDEWEB)

    Shen, Bo [ORNL; Abdelaziz, Omar [ORNL; Rice, C Keith [ORNL; Baxter, Van D [ORNL

    2016-01-01

    In cold climate zones, e.g. ASHRAE climate regions IV and V, conventional electric air-source heat pumps (ASHP) do not work well, due to high compressor discharge temperatures, large pressure ratios and inadequate heating capacities at low ambient temperatures. Consequently, significant use of auxiliary strip heating is required to meet the building heating load. We introduce innovative ASHP technologies as part of continuing efforts to eliminate auxiliary strip heat use and maximize heating COP with acceptable cost-effectiveness and reliability. These innovative ASHP were developed using tandem compressors, which are capable of augmenting heating capacity at low temperatures and maintain superior part-load operation efficiency at moderate temperatures. Two options of tandem compressors were studied; the first employs two identical, single-speed compressors, and the second employs two identical, vapor-injection compressors. The investigations were based on system modeling and laboratory evaluation. Both designs have successfully met the performance criteria. Laboratory evaluation showed that the tandem, single-speed compressor ASHP system is able to achieve heating COP = 4.2 at 47 F (8.3 C), COP = 2.9 at 17 F (-8.3 C), and 76% rated capacity and COP = 1.9 at -13 F (-25 C). This yields a HSPF = 11.0 (per AHRI 210/240). The tandem, vapor-injection ASHP is able to reach heating COP = 4.4 at 47 F, COP = 3.1 at 17 F, and 88% rated capacity and COP = 2.0 at -13 F. This yields a HSPF = 12.0. The system modeling and further laboratory evaluation are presented in the paper.

  5. Financial Arrangements and Relationship Quality in Low-Income Couples

    Science.gov (United States)

    Addo, Fenaba R.; Sassler, Sharon

    2010-01-01

    This study explored the association between household financial arrangements and relationship quality using a representative sample of low-income couples with children. We detailed the banking arrangements couples utilize, assessed which factors relate to holding a joint account versus joint and separate, only separate, or no account, and analyzed…

  6. Flexible Work Arrangements in ARL Libraries. SPEC Kit #180.

    Science.gov (United States)

    Zabel, Diane, Comp.; And Others

    This report presents the results of a survey of Association of Research Libraries (ARL) members about the current climate and practices regarding flexible work arrangements. Data are reported on the availability of schedule flexibility, job exchange, part-time arrangements, and leaves, as well as information about faculty status, tenure,…

  7. 28 CFR 550.44 - Procedures for arranging drug counseling.

    Science.gov (United States)

    2010-07-01

    ... 28 Judicial Administration 2 2010-07-01 2010-07-01 false Procedures for arranging drug counseling... MANAGEMENT DRUG PROGRAMS Drug Services (Urine Surveillance and Counseling for Sentenced Inmates in Contract CTCs) § 550.44 Procedures for arranging drug counseling. The contract center staff shall hold a program...

  8. 48 CFR 3001.105-1 - Publication and code arrangement.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 7 2010-10-01 2010-10-01 false Publication and code arrangement. 3001.105-1 Section 3001.105-1 Federal Acquisition Regulations System DEPARTMENT OF HOMELAND... Purpose, Authority, Issuance 3001.105-1 Publication and code arrangement. (a) The HSAR is published in: (1...

  9. 48 CFR 501.105-1 - Publication and code arrangement.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 4 2010-10-01 2010-10-01 false Publication and code arrangement. 501.105-1 Section 501.105-1 Federal Acquisition Regulations System GENERAL SERVICES... 501.105-1 Publication and code arrangement. The GSAR is published in the following sources: (a) Daily...

  10. Ulysses arrangements in psychiatry: a matter of good care?

    NARCIS (Netherlands)

    Gremmen, I.; Widdershoven, G.A.M.; Beekman, A.T.F.; Zuijderhoudt, R.H.; Sevenhuijsen, S.

    2008-01-01

    This article concerns the issue of how an ethic of care perspective may contribute to both normative theory and mental health care policy discussions on so called Ulysses arrangements, a special type of advance directives in psychiatry. The debate on Ulysses arrangements has predominantly been waged

  11. Ulysses Arrangements in psychiatry: A matter of good care?

    NARCIS (Netherlands)

    Gremmen, C.C.M.; Widdershoven, G.G; Beekman, A; Zuijderhoudt, R.; Sevenhuijsen, S.

    2008-01-01

    This article concerns the issue of how an ethic of care perspective may contribute to both normative theory and mental health care policy discussions on so called Ulysses arrangements, a special type of advance directives in psychiatry. The debate on Ulysses arrangements has predominantly been waged

  12. 29 CFR 780.126 - Contract arrangements for raising poultry.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 3 2010-07-01 2010-07-01 false Contract arrangements for raising poultry. 780.126 Section... General Scope of Agriculture Raising of Livestock, Bees, Fur-Bearing Animals, Or Poultry § 780.126 Contract arrangements for raising poultry. Feed dealers and processors sometimes enter into contractual...

  13. Do Knowledge Arrangements Affect Student Reading Comprehension of Genetics?

    Science.gov (United States)

    Wu, Jen-Yi; Tung, Yu-Neng; Hwang, Bi-Chi; Lin, Chen-Yung; Che-Di, Lee; Chang, Yung-Ta

    2014-01-01

    Various sequences for teaching genetics have been proposed. Three seventh-grade biology textbooks in Taiwan share similar key knowledge assemblages but have different knowledge arrangements. To investigate the influence of knowledge arrangements on student understanding of genetics, we compared students' reading comprehension of the three texts…

  14. 29 CFR 779.230 - Franchise and other arrangements.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 3 2010-07-01 2010-07-01 false Franchise and other arrangements. 779.230 Section 779.230... Coverage Leased Departments, Franchise and Other Business Arrangements § 779.230 Franchise and other.... The quotation in § 779.229 from the Senate Report shows that Congress recognized that some franchise...

  15. On capital allocation for stochastic arrangement increasing actuarial risks

    Directory of Open Access Journals (Sweden)

    Pan Xiaoqing

    2017-01-01

    Full Text Available This paper studies the increasing convex ordering of the optimal discounted capital allocations for stochastic arrangement increasing risks with stochastic arrangement decreasing occurrence times. The application to optimal allocation of policy limits is presented as an illustration as well.

  16. European top managers’ support for work-life arrangements

    NARCIS (Netherlands)

    Been, Wike M.; van der Lippe, Tanja; den Dulk, Laura; Das Dores Horta Guerreiro, Maria; Kanjuo Mrčela, Aleksandra; Niemistö, Charlotta

    2017-01-01

    Top managers—defined as CEOs, CFOs and members of boards of directors—decide to what degree their organization offers employees work-life arrangements. This study focuses on the conditions under which they support such arrangements. A factorial survey of 202 top managers in five European countries

  17. The effects of different source arrangement on the irradiation efficacy

    International Nuclear Information System (INIS)

    Liu Hongyue; Shi Peixin; Lin Yin

    1999-01-01

    The effects of 8 different arrangements with 16 pencil sources on irradiation productivity were studied by using a self-designed computer program. The results showed that the fashion of decentralized arrangement had a higher irradiation productivity than that of centralized in a static and uniform field

  18. TandEM: Titan and Enceladus mission

    Science.gov (United States)

    Coustenis, A.; Atreya, S.K.; Balint, T.; Brown, R.H.; Dougherty, M.K.; Ferri, F.; Fulchignoni, M.; Gautier, D.; Gowen, R.A.; Griffith, C.A.; Gurvits, L.I.; Jaumann, R.; Langevin, Y.; Leese, M.R.; Lunine, J.I.; McKay, C.P.; Moussas, X.; Muller-Wodarg, I.; Neubauer, F.; Owen, T.C.; Raulin, F.; Sittler, E.C.; Sohl, F.; Sotin, Christophe; Tobie, G.; Tokano, T.; Turtle, E.P.; Wahlund, J.-E.; Waite, J.H.; Baines, K.H.; Blamont, J.; Coates, A.J.; Dandouras, I.; Krimigis, T.; Lellouch, E.; Lorenz, R.D.; Morse, A.; Porco, C.C.; Hirtzig, M.; Saur, J.; Spilker, T.; Zarnecki, J.C.; Choi, E.; Achilleos, N.; Amils, R.; Annan, P.; Atkinson, D.H.; Benilan, Y.; Bertucci, C.; Bezard, B.; Bjoraker, G.L.; Blanc, M.; Boireau, L.; Bouman, J.; Cabane, M.; Capria, M.T.; Chassefiere, E.; Coll, P.; Combes, M.; Cooper, J.F.; Coradini, A.; Crary, F.; Cravens, T.; Daglis, I.A.; de Angelis, E.; De Bergh, C.; de Pater, I.; Dunford, C.; Durry, G.; Dutuit, O.; Fairbrother, D.; Flasar, F.M.; Fortes, A.D.; Frampton, R.; Fujimoto, M.; Galand, M.; Grasset, O.; Grott, M.; Haltigin, T.; Herique, A.; Hersant, F.; Hussmann, H.; Ip, W.; Johnson, R.; Kallio, E.; Kempf, S.; Knapmeyer, M.; Kofman, W.; Koop, R.; Kostiuk, T.; Krupp, N.; Kuppers, M.; Lammer, H.; Lara, L.-M.; Lavvas, P.; Le, Mouelic S.; Lebonnois, S.; Ledvina, S.; Li, Ji; Livengood, T.A.; Lopes, R.M.; Lopez-Moreno, J. -J.; Luz, D.; Mahaffy, P.R.; Mall, U.; Martinez-Frias, J.; Marty, B.; McCord, T.; Salvan, C.M.; Milillo, A.; Mitchell, D.G.; Modolo, R.; Mousis, O.; Nakamura, M.; Neish, Catherine D.; Nixon, C.A.; Mvondo, D.N.; Orton, G.; Paetzold, M.; Pitman, J.; Pogrebenko, S.; Pollard, W.; Prieto-Ballesteros, O.; Rannou, P.; Reh, K.; Richter, L.; Robb, F.T.; Rodrigo, R.; Rodriguez, S.; Romani, P.; Bermejo, M.R.; Sarris, E.T.; Schenk, P.; Schmitt, B.; Schmitz, N.; Schulze-Makuch, D.; Schwingenschuh, K.; Selig, A.; Sicardy, B.; Soderblom, L.; Spilker, L.J.; Stam, D.; Steele, A.; Stephan, K.; Strobel, D.F.; Szego, K.; Szopa,

    2009-01-01

    TandEM was proposed as an L-class (large) mission in response to ESA’s Cosmic Vision 2015–2025 Call, and accepted for further studies, with the goal of exploring Titan and Enceladus. The mission concept is to perform in situ investigations of two worlds tied together by location and properties, whose remarkable natures have been partly revealed by the ongoing Cassini–Huygens mission. These bodies still hold mysteries requiring a complete exploration using a variety of vehicles and instruments. TandEM is an ambitious mission because its targets are two of the most exciting and challenging bodies in the Solar System. It is designed to build on but exceed the scientific and technological accomplishments of the Cassini–Huygens mission, exploring Titan and Enceladus in ways that are not currently possible (full close-up and in situ coverage over long periods of time). In the current mission architecture, TandEM proposes to deliver two medium-sized spacecraft to the Saturnian system. One spacecraft would be an orbiter with a large host of instruments which would perform several Enceladus flybys and deliver penetrators to its surface before going into a dedicated orbit around Titan alone, while the other spacecraft would carry the Titan in situ investigation components, i.e. a hot-air balloon (Montgolfière) and possibly several landing probes to be delivered through the atmosphere.

  19. Feedback stabilized tandem Fabry-Perot interferometer

    International Nuclear Information System (INIS)

    Fukushima, Hiroyuki; Ito, Mikio; Shirasu, Hiroshi.

    1986-01-01

    A new system for measuring the isotopic ratio of uranium, in which two plane-type Fabry-Perot interferometers (tandem FP) are connected in series. The parallelism between the two FPs is achieved automatically by a feedback control mechanism based on laser interference fringe monitoring. The structure of the tandem FP, feedback control system, automatic parallelism adjustment mechanism and wavelength synchronization mechanism are described in detail. For experiments, a hollow cathode discharge tube of a pulse discharge type is employed. Measurements are made to determine the effects of pulse width on the 238 U peak height of 502.7 nm line, recorder traces of 235 U and 238 U lines, half width for 238 U component of the 502.7 nm line, SN ratio, reproducibility of the 235 U/ 238 U peak height ratio and 235 U/ 238 U intensity ratio. Considerations are made on the spectral line width, contrast, transmission factor, and stability of automatic parallelism control and wavelength synchronization. Results obtained indicates that a single-type interferometer would serve adequately for measuring the 235 U/ 238 U ratio if the automatic parallelism control developed here is used. The ultimate object of the tandem system is to make measurement of 236 U. Satisfactory results have not obtained as yet, but most likely the present system would make it possible if a light source of a higher intensity and advanced photometric techniques are developed. (Nogami, K.)

  20. ORNL 25 MV tandem accelerator control system

    International Nuclear Information System (INIS)

    Juras, R.C.; Biggerstaff, J.A.; Hoglund, D.E.

    1985-01-01

    The CAMAC-based control system for the 25 MV tandem electrostatic accelerator of the Holifield Heavy Ion Research Facility at Oak Ridge National Laboratory (ORNL) was specified by ORNL and built by the National Electrostatics Corporation. Two Perkin-Elmer 32-bit minicomputers are used in the system, a message switching computer and a supervisory computer. The message switching computer transmits and receives control information on six serial highways. This computer shares memory with the supervisory computer. Operator consoles are located on a serial highway; control is by means of a console CRT, trackball, and assignable shaft encoders and meters. Two identical consoles operate simultaneously: one is located in the tandem control room; the other is located in the cyclotron control room to facilitate operation during injection of tandem beams into the cyclotron or when beam lines under control of the cyclotron control system are used. The supervisory computer is used for accelerator parameter setup calculations, actual accelerator setup for new beams based on scaled, recorded parameters from previously run beams, and various other functions. Nearly seven years of control system operation and improvements will be discussed

  1. BIRTHDAY CAKE ACTIVITY STRUCTURED ARRANGEMENT FOR HELPING CHILDREN DETERMINING QUANTITIES

    Directory of Open Access Journals (Sweden)

    Neni Mariana

    2010-07-01

    Full Text Available Few researches have been concerned about relation between children’s spatialthinking and number sense. Narrowing for this small research, we focused onone component of spatial thinking, that is structuring objects, and onecomponent of number senses, that is cardinality by determining quantities. Thisstudy focused on a design research that was conducted in Indonesia in which weinvestigated pre-school children’s (between 2 and 3.5 years old ability inmaking structured arrangement and their ability to determine the quantities bylooking at the arrangements. The result shows us that some of the children wereable to make such arrangement. However, the children found difficulties eitherto determine quantities from those arrangements or to compare some structuresto easily recognize number of objects.Keywords: structures, structured arrangement, cardinality DOI: http://dx.doi.org/10.22342/jme.1.1.790.53-70

  2. Thermodynamic characterization of tandem mismatches found in naturally occurring RNA

    Science.gov (United States)

    Christiansen, Martha E.; Znosko, Brent M.

    2009-01-01

    Although all sequence symmetric tandem mismatches and some sequence asymmetric tandem mismatches have been thermodynamically characterized and a model has been proposed to predict the stability of previously unmeasured sequence asymmetric tandem mismatches [Christiansen,M.E. and Znosko,B.M. (2008) Biochemistry, 47, 4329–4336], experimental thermodynamic data for frequently occurring tandem mismatches is lacking. Since experimental data is preferred over a predictive model, the thermodynamic parameters for 25 frequently occurring tandem mismatches were determined. These new experimental values, on average, are 1.0 kcal/mol different from the values predicted for these mismatches using the previous model. The data for the sequence asymmetric tandem mismatches reported here were then combined with the data for 72 sequence asymmetric tandem mismatches that were published previously, and the parameters used to predict the thermodynamics of previously unmeasured sequence asymmetric tandem mismatches were updated. The average absolute difference between the measured values and the values predicted using these updated parameters is 0.5 kcal/mol. This updated model improves the prediction for tandem mismatches that were predicted rather poorly by the previous model. This new experimental data and updated predictive model allow for more accurate calculations of the free energy of RNA duplexes containing tandem mismatches, and, furthermore, should allow for improved prediction of secondary structure from sequence. PMID:19509311

  3. Thermal analysis of a helium-cooled, tube-bank blanket module for a tandem mirror fusion reactor

    International Nuclear Information System (INIS)

    Werner, R.W.

    1983-01-01

    A blanket module concept for the central cell of a tandem mirror reactor is described which takes advantage of the excellent heat transfer and low pressure drop characteristics of tube banks in cross-flow. The blanket employs solid Li 2 O as the tritium breeding material and helium as the coolant. The lithium oxide is contained in tubes arranged within the submodules as a two-pass, cross-flow heat exchanger. Primarily, the heat transfer and thermal-hydraulic aspects of the blanket design study are described in this paper. In particular, the analytical model used for selection of the best tube-bank design parameters is discussed in some detail

  4. Thermal analysis of a helium-cooled, tube-bank blanket module for a tandem-mirror fusion reactor

    International Nuclear Information System (INIS)

    Werner, R.W.; Hoffman, M.A.; Johnson, G.L.

    1983-01-01

    A blanket module concept for the central cell of a tandem mirror reactor is described which takes advantage of the excellent heat transfer and low pressure drop characteristics of tube banks in cross-flow. The blanket employs solid Li 2 O as the tritium breeding material and helium as the coolant. The lithium oxide is contained in tubes arranged within the submodules as a two-pass, cross-flow heat exchanger. Primarily, the heat transfer and thermal-hydraulic aspects of the blanket design study are described in this paper. In particular, the analytical model used for selection of the best tube-bank design parameters is discussed in some detail

  5. Actualization of the Tandem-E N Accelerator of the Nuclear Centre of Mexico

    International Nuclear Information System (INIS)

    Villasenor S, P.; Aguilera R, E.; Aspiazu F, J.; Fernandez A, J.; Fernandez B, M.; Garcia R, B.; Lopez M, J.; Martinez Q, E.; Mendez G, B.; Moreno B, E.; Murillo O, G.; Policroniades R, R.; Ramirez T, J.; Reynoso V, R.; Varela G, A.; Vega C, J.

    2004-01-01

    In this work, the activities are described carried out to change the tubes accelerators and original resistances of the accelerator Tandem-E N of the Nuclear Center, for tubes DOWLISH and resistances again design, both donated ones for ORNL. This way same, the problem is described that imply this changes, and like it was solved by the personnel of the laboratory, without having to appeal to external services, what there is redounded in a considerable increment in the costs. In form preliminary the improvements are described observed after the rehabilitation of the Accelerator. (Author)

  6. METHOD FOR DETERMINING THE MAXIMUM ARRANGEMENT FACTOR OF FOOTWEAR PARTS

    Directory of Open Access Journals (Sweden)

    DRIŞCU Mariana

    2014-05-01

    Full Text Available By classic methodology, designing footwear is a very complex and laborious activity. That is because classic methodology requires many graphic executions using manual means, which consume a lot of the producer’s time. Moreover, the results of this classical methodology may contain many inaccuracies with the most unpleasant consequences for the footwear producer. Thus, the costumer that buys a footwear product by taking into consideration the characteristics written on the product (size, width can notice after a period that the product has flaws because of the inadequate design. In order to avoid this kind of situations, the strictest scientific criteria must be followed when one designs a footwear product. The decisive step in this way has been made some time ago, when, as a result of powerful technical development and massive implementation of electronical calculus systems and informatics, This paper presents a product software for determining all possible arrangements of a footwear product’s reference points, in order to automatically acquire the maximum arrangement factor. The user multiplies the pattern in order to find the economic arrangement for the reference points. In this purpose, the user must probe few arrangement variants, in the translation and rotate-translation system. The same process is used in establishing the arrangement factor for the two points of reference of the designed footwear product. After probing several variants of arrangement in the translation and rotation and translation systems, the maximum arrangement factors are chosen. This allows the user to estimate the material wastes.

  7. Spatial arrangement of faults and opening-mode fractures

    Science.gov (United States)

    Laubach, S. E.; Lamarche, J.; Gauthier, B. D. M.; Dunne, W. M.; Sanderson, David J.

    2018-03-01

    Spatial arrangement is a fundamental characteristic of fracture arrays. The pattern of fault and opening-mode fracture positions in space defines structural heterogeneity and anisotropy in a rock volume, governs how faults and fractures affect fluid flow, and impacts our understanding of the initiation, propagation and interactions during the formation of fracture patterns. This special issue highlights recent progress with respect to characterizing and understanding the spatial arrangements of fault and fracture patterns, providing examples over a wide range of scales and structural settings. Five papers describe new methods and improvements of existing techniques to quantify spatial arrangement. One study unravels the time evolution of opening-mode fracture spatial arrangement, which are data needed to compare natural patterns with progressive fracture growth in kinematic and mechanical models. Three papers investigate the role of evolving diagenesis in localizing fractures by mechanical stratigraphy and nine discuss opening-mode fracture spatial arrangement. Two papers show the relevance of complex cluster patterns to unconventional reservoirs through examples of fractures in tight gas sandstone horizontal wells, and a study of fracture arrangement in shale. Four papers demonstrate the roles of folds in fracture localization and the development spatial patterns. One paper models along-fault friction and fluid pressure and their effects on fault-related fracture arrangement. Contributions address deformation band patterns in carbonate rocks and fault size and arrangement above a detachment fault. Three papers describe fault and fracture arrangements in basement terrains, and three document fracture patterns in shale. This collection of papers points toward improvement in field methods, continuing improvements in computer-based data analysis and creation of synthetic fracture patterns, and opportunities for further understanding fault and fracture attributes in

  8. William Barlow and the Determination of Atomic Arrangement in Crystals.

    Science.gov (United States)

    Mauskopf, Seymour H

    2015-04-01

    William Barlow (1845-1934) was an important if unconventional scientist, known for having developed the 'closest-packing' atomic models of crystal structure. He resumed an early nineteenth-century tradition of utilizing crystallographical and chemical data to determine atomic arrangements in crystals. This essay recounts Barlow's career and scientific activity in three parts: (a) His place in the tradition of determining atomic arrangement in context of this earlier tradition and of contemporaneous developments of crystallography and chemistry, (b) his unconventional career, and (c) the 'success' of his program to determine atomic arrangements in crystals and its influence on the work of William Lawrence Bragg.

  9. Brief-stimulus presentations on multiform tandem schedules

    OpenAIRE

    Reed, Phil

    1994-01-01

    Three experiments examined the influence of a brief stimulus (a light) on the behavior of food-deprived rats whose lever pressing on tandem schedules comprising components of different schedule types resulted in food presentation. In Experiment 1, either a tandem variable-ratio variable-interval or a tandem variable-interval variable-ratio schedule was used. The variable-interval requirement in the tandem variable-ratio variable-interval schedule was yoked to the time taken to complete the va...

  10. Flexible and fragmentable tandem photosensitive nanocrystal skins

    Science.gov (United States)

    Akhavan, S.; Uran, C.; Bozok, B.; Gungor, K.; Kelestemur, Y.; Lesnyak, V.; Gaponik, N.; Eychmüller, A.; Demir, H. V.

    2016-02-01

    We proposed and demonstrated the first account of large-area, semi-transparent, tandem photosensitive nanocrystal skins (PNSs) constructed on flexible substrates operating on the principle of photogenerated potential buildup, which avoid the need for applying an external bias and circumvent the current-matching limitation between junctions. We successfully fabricated and operated the tandem PNSs composed of single monolayers of colloidal water-soluble CdTe and CdHgTe nanocrystals (NCs) in adjacent junctions on a Kapton polymer tape. Owing to the usage of a single NC layer in each junction, noise generation was significantly reduced while keeping the resulting PNS films considerably transparent. In each junction, photogenerated excitons are dissociated at the interface of the semi-transparent Al electrode and the NC layer, with holes migrating to the contact electrode and electrons trapped in the NCs. As a result, the tandem PNSs lead to an open-circuit photovoltage buildup equal to the sum of those of the two single junctions, exhibiting a total voltage buildup of 128.4 mV at an excitation intensity of 75.8 μW cm-2 at 350 nm. Furthermore, we showed that these flexible PNSs could be bent over 3.5 mm radius of curvature and cut out in arbitrary shapes without damaging the operation of individual parts and without introducing any significant loss in the total sensitivity. These findings indicate that the NC skins are promising as building blocks to make low-cost, flexible, large-area UV/visible sensing platforms with highly efficient full-spectrum conversion.We proposed and demonstrated the first account of large-area, semi-transparent, tandem photosensitive nanocrystal skins (PNSs) constructed on flexible substrates operating on the principle of photogenerated potential buildup, which avoid the need for applying an external bias and circumvent the current-matching limitation between junctions. We successfully fabricated and operated the tandem PNSs composed of

  11. CFD simulation and validation of turbulent mixing in a rod bundle with vaned spacer grids based on LDV test

    International Nuclear Information System (INIS)

    Chen Xi; Li Songwei; Li Zhongchun; Du Sijia; Zhang Yu; Peng Huanhuan

    2017-01-01

    Spacer grids with mixing vanes are generally used in fuel assemblies of Pressurized Water Reactor (PWR), because that mixing vanes could enhance the lateral turbulent mixing in subchannels. Thus, heat exchangements are more efficient, and the value of departure from nucleate boiling (DNB) is greatly increased. Actually turbulent mixing is composed of two kinds of flows: swirling flow inside the subchannel and cross flow between subchannels. Swirling flow could induce mixing between hot water near the rod and cold water in the center of the subchannel, and may accelerate deviation of the bubbles from the rod surface. Besides, crossing flow help to mixing water between hot subchannels and cold subchannels, which impact relatively large flow area. As a result, how to accurately capture and how to predict the complicated mixing phenomenon are of great concernments. Recently many experimental studies has been conducted to provide detailed turbulent mixing in rod bundle, among which Laser Doppler Velocimetry method is widely used. With great development of Computational Fluid Dynamics, CFD has been validated as an analysis method for nuclear engineering, especially for single phase calculation. This paper presents the CFD simulation and validation of the turbulent mixing induced by spacer grid with mixing vanes in rod bundles. Experiment data used for validation came from 5 x 5 rod bundle test with LDV technology, which is organized by Science and Technology on Reactor System Design Technology Laboratory. A 5 x 5 rod bundle with two spacer grids were used. Each rod has dimension of 9.5 mm in outer diameter and distance between rods is 12.6 mm. Two axial bulk velocities were conducted at 3.0 m/s for high Reynolds number and 1.0 m/s for low Reynolds number. Working pressure was 1.0 bar, and temperature was about 25degC. Two different distances from the downstream of the mixing spacer grid and one from upstream were acquired. Mean axial velocities and turbulent intensities

  12. Tandem junction amorphous semiconductor photovoltaic cell

    Science.gov (United States)

    Dalal, Vikram L.

    1983-01-01

    A photovoltaic stack comprising at least two p.sup.+ i n.sup.+ cells in optical series, said cells separated by a transparent ohmic contact layer(s), provides a long optical path for the absorption of photons while preserving the advantageous field-enhanced minority carrier collection arrangement characteristic of p.sup.+ i n.sup.+ cells.

  13. Some new ideas for Tandem Mirror blankets

    International Nuclear Information System (INIS)

    Neef, W.S. Jr.

    1981-01-01

    The Tandem Mirror Reactor, with its cylindrical central cell, has led to numerous blanket designs taking advantage of the simple geometry. Also many new applications for fusion neutrons are now being considered. To the pure fusion electricity producers and hybrids producing fissile fuel, we are adding studies of synthetic fuel producers and fission-suppressed hybrids. The three blanket concepts presented are new ideas and should be considered illustrative of the breadth of Livermore's application studies. They are not meant to imply fully analyzed designs

  14. Tandem mirror and tokamak reactor maintainability comparison

    International Nuclear Information System (INIS)

    Zahn, H.S.

    1981-01-01

    The analysis proceeds through estimates of downtime and resources required for selected maintenance actions and optimization of the replacement fraction, availability and cost of electricity. Scheduled downtime estimates and availability goals provide a basis for determining allowable forced outage downtimes. These analyses have been conducted with the assumption of redundancy wherever feasible but without the impact of maintenance equipment outages. Annual maintenance cost estimates and availabilities for both reactors are found to be approximately equal. However, the tandem mirror reactor capital costs are higher. Reduction of these costs appears feasible with the trend of current design studies toward smaller and more accessible machines

  15. Parametric systems analysis for tandem mirror hybrids

    International Nuclear Information System (INIS)

    Lee, J.D.; Chapin, D.L.; Chi, J.W.H.

    1980-09-01

    Fusion fission systems, consisting of fissile producing fusion hybrids combining a tandem mirror fusion driver with various blanket types and net fissile consuming LWR's, have been modeled and analyzed parametrically. Analysis to date indicates that hybrids can be competitive with mined uranium when U 3 O 8 cost is about 100 $/lb., adding less than 25% to present day cost of power from LWR's. Of the three blanket types considered, uranium fast fission (UFF), thorium fast fission (ThFF), and thorium fission supressed (ThFS), the ThFS blanket has a modest economic advantage under most conditions but has higher support ratios and potential safety advantages under all conditions

  16. NSF tandem stack support structure deflection characteristics

    International Nuclear Information System (INIS)

    Cook, J.

    1979-12-01

    Results are reported of load tests carried out on the glass legs of the insulating stack of the 30 MV tandem Van de Graaff accelerator now under construction at Daresbury Laboratory. The tests to investigate the vulnerability of the legs when subjected to tensile stresses were designed to; establish the angle of rotation of the pads from which the stresses in the glass legs may be calculated, proof-test the structure and at the same time reveal any asymmetry in pad rotations or deflections, and to confirm the validity of the computer design analysis. (UK)

  17. A tandem queue with delayed server release

    OpenAIRE

    Nawijn, W.M.

    1997-01-01

    We consider a tandem queue with two stations. The rst station is an s-server queue with Poisson arrivals and exponential service times. After terminating his service in the rst station, a customer enters the second station to require service at an exponential single server, while in the meantime he is blocking his server in station 1 until he completes service in station 2, whereupon the server in station 1 is released. An analysis of the generating function of the simultaneous probability di...

  18. Negative ion sources for tandem accelerator

    International Nuclear Information System (INIS)

    Minehara, Eisuke

    1980-08-01

    Four kinds of negative ion sources (direct extraction Duoplasmatron ion source, radial extraction Penniing ion source, lithium charge exchange ion source and Middleton-type sputter ion source) have been installed in the JAERI tandem accelerator. The ion sources can generate many negative ions ranging from Hydrogen to Uranium with the exception of Ne, Ar, Kr, Xe and Rn. Discussions presented in this report include mechanisms of negative ion formation, electron affinity and stability of negative ions, performance of the ion sources and materials used for negative ion production. Finally, the author will discuss difficult problems to be overcome in order to get any negative ion sufficiently. (author)

  19. Plasma confinement in the TMX tandem mirror

    International Nuclear Information System (INIS)

    Hooper, E.B. Jr.; Allen, S.L.; Casper, T.A.

    1981-01-01

    Plasma confinement in the Tandem Mirror Experiment (TMX) is described. Axially confining potentials are shown to exist throughout the central 20-cm core of TMX. Axial electron-confinement time is up to 100 times that of single-cell mirror machines. Radial transport of ions is smaller than axial transport near the axis. It has two parts at large radii: nonambipolar, in rough agreement with predictions from resonant-neoclassical transport theory, and ambipolar, observed near the plasma edge under certain conditions, accompanied by a low-frequency, m = 1 instability or strong turbulence

  20. Tandem Carbocupration/Oxygenation of Terminal Alkynes

    Science.gov (United States)

    Zhang, Donghui; Ready, Joseph M.

    2008-01-01

    A direct and general synthesis of α-branched aldehydes and their enol derivatives is described. Carbocupration of terminal alkynes and subsequent oxygenation with lithium tert-butyl peroxide generates a metallo-enolate. Trapping with various electrophiles provides α-branched aldehydes or stereo-defined trisubstituted enol esters or silyl ethers. The tandem carbocupration/oxygenation tolerates alkyl and silyl ethers, esters and tertiary amines. The reaction is effective with organocopper complexes derived from primary, secondary and tertiary Grignard reagents and from n-butyllithium. PMID:16321021

  1. Beam trajectories through the upgraded XTU tandem

    International Nuclear Information System (INIS)

    Guan Xialing

    1988-01-01

    The paper deals with a problem applicable to all electrostatic accelerators with inclined field accelerating tubes, how the trajectory of the central beam particle is affected if one of the accelerating gaps must be shorted out due to insulator failure. For the long tube of the Legnaro XTU tandem the effect of each accelerator gap is calculated and a method of compensation either by shorting out an appropriate gap with reversed incline or by appropriately steering the beam into the entrance of the low energy tube is given. (orig.)

  2. Fuel arrangement for high temperature gas cooled reactor

    International Nuclear Information System (INIS)

    Tobin, J.M.

    1978-01-01

    Disclosed is a fuel arrangement for a high temperature gas cooled reactor including fuel assemblies with separate directly cooled fissile and fertile fuel elements removably inserted in an elongated moderator block also having a passageway for control elements

  3. Arrangement to reduce the failure frequency of heat condensate pipes

    International Nuclear Information System (INIS)

    Liskow, E.; Apelt, W.; Krause, W.; Meisel, L.

    1988-01-01

    The arrangement of throttling devices in heat condensate pipes of NPP with WWER-440 type reactors aims at reducing their failure frequency, ensuring an energetically favourable operation, and enhancing the availability and safety of NPP units

  4. Friendship Repertoires and Care Arrangement: A Praxeological Approach.

    Science.gov (United States)

    Hahmann, Julia

    2017-01-01

    Friends are important companions and serve as sources for diverse dimensions of social support, including elderly care. Rather than researching populations that have already established care arrangements including friends, the author seeks to understand relationship systems with a focus on the inner logic friendship to consequently describe and understand involved care arrangements, be it with family members or friends. To illustrate the diversity of friendship repertoires, qualitative interviews with older adult Germans are analyzed regarding cognitive concepts of friendships in contrast to familiar ties as well as social practices around relationship systems. While some repertoires successfully include chosen ties in their care arrangements, others not only focus on family, they do not wish to receive care from friends. The article's praxeological approach highlights the need to reflect habitual differences when thinking about elderly informal care arrangements. © The Author(s) 2016.

  5. The new electricity trading arrangements: prospects for market development

    International Nuclear Information System (INIS)

    Anon

    1999-09-01

    This Briefing Paper from OXERA argues that the OFGEM proposals will not solve the fundamental market problems and might even make things worse. They focus too narrowly on the technical design of one small part of the market (the Balancing Mechanism and associated imbalance settlement process), without considering the market context and dynamics. OXERA argues that the central emphasis of the White Paper was misplaced: reform of the electricity trading arrangements, the basis of the government's strategy, will not solve the upstream and downstream market problems. The Briefing Paper includes analysis of: the structure and operation of the proposed new electricity trading arrangements; risk in the electricity wholesale market, and the responses of market participants; the interaction between the new trading arrangements and other energy market developments - in particular, vertical integration between generators and suppliers; energy supply competition, and wider government policy; the prospects for market development under the new electricity trading arrangements. (author)

  6. Birthday Cake Activity Structured Arrangement for Helping Children Determining Quantities

    Directory of Open Access Journals (Sweden)

    Neni Mariana

    2010-07-01

    Full Text Available Few researches have been concerned about relation between children’s spatial thinking and number sense. Narrowing for this small research, we focused on one component of spatial thinking, that is structuring objects, and one component of number senses, that is cardinality by determining quantities. This study focused on a design research that was conducted in Indonesia in which we investigated pre-school children’s (between 2 and 3.5 years old ability in making structured arrangement and their ability to determine the quantities by looking at the arrangements. The result shows us that some of the children were able to make such arrangement. However, the children found difficulties either to determine quantities from those arrangements or to compare some structures to easily recognize number of objects.

  7. Evolution of Land Rental Arrangements in Rural Ghana: Evidence ...

    African Journals Online (AJOL)

    zones of Ghana, their varied characters, trends of evolution, and the driving forces .... arrangements have not been given the needed attention in policy, perhaps due to ... markets follows a five-stage trajectory, which can broadly be divided into.

  8. Children's postdivorce residence arrangements and parental experienced time pressure

    NARCIS (Netherlands)

    van der Heijden, Franciëlla; Poortman, Anne Rigt; van der Lippe, Tanja

    2016-01-01

    Although the rise in postdivorce joint physical custody has fueled scholarly interest in its impact on children, consequences for parents remain understudied. Because children's residence arrangements determine time and coordination demands associated with child care, this study investigated the

  9. The magnet power control system for the tandem mirror experiment-upgrade

    International Nuclear Information System (INIS)

    Bell, H.H.

    1983-01-01

    This paper describes the desktop computer/CAMAC based system that controls the power source for the Tandem Mirror Experiment-Upgrade (TMX-U) magnet power system. Presently it contains 42 dc rectifier power supplies connected to 24 magnet coils arranged in 17 circuits. During each shot, the system delivers 22.6 MW dc to the magnets for about 3 s. The system is presently being changed to add six power supplies, two solenoidal throttle coils, and two reverse C-coils. When complete, the delivered power will increase to 36.9 MW. The closed-loop control system usually provides current (and thus, magnetic field) that is within 1% of the requested current. Achieving this accuracy required using grounding, shielding, and isolation methods to reduce noise and related problems

  10. The design, simulation and testing of an urban vertical axis wind turbine with the omni-direction-guide-vane

    International Nuclear Information System (INIS)

    Chong, W.T.; Fazlizan, A.; Poh, S.C.; Pan, K.C.; Hew, W.P.; Hsiao, F.B.

    2013-01-01

    Graphical abstract: Solar energy, renewable energy, urban wind energy, environment, augmented wind turbine. Highlights: ► A system for on-site wind–solar hybrid power generation and rain water collection. ► The omni-direction-guide-vane (ODGV) overcomes the weak wind and turbulence conditions in urban areas. ► The ODGV improves the wind turbine performance by speeding-up and guiding the wind. ► The ODGV is designed to blend into the building architecture with safety enhancement. ► The wind tunnel test and CFD simulation results are presented. - Abstract: A novel omni-direction-guide-vane (ODGV) that surrounds a vertical axis wind turbine (VAWT) is designed to improve the wind turbine performance. Wind tunnel testing was performed to evaluate the performance of a 5-bladed (Wortmann FX63-137 airfoil) H-rotor wind turbine, with and without the integration of the ODGV. The test was conducted using a scaled model turbine which was constructed to simulate the VAWT enclosed by the ODGV placed on a building. The VAWT shows an improvement on its self-starting behavior where the cut-in speed was reduced with the integration of the ODGV. Since the VAWT is able to self-start at a lower wind speed, the working hour of the wind turbine would increase. At a wind speed of 6 m/s and under free-running condition (only rotor inertia and bearing friction were applied), the ODGV helps to increase the rotor rotational speed by 182%. With extra load application at the same wind speed (6 m/s), the wind turbine power output was increased by 3.48 times at its peak torque with the aid of the ODGV. The working concept of the ODGV is to minimize the negative torque zone of a lift-type VAWT and to reduce turbulence and rotational speed fluctuation. It was verified by re-simulating the torque coefficient data of a single bladed (NACA 0015 airfoil) VAWT published by the Sandia National Laboratories. From the simulation results, with the presence of the ODGV, it was shown that the

  11. TACT1- TRANSIENT THERMAL ANALYSIS OF A COOLED TURBINE BLADE OR VANE EQUIPPED WITH A COOLANT INSERT

    Science.gov (United States)

    Gaugler, R. E.

    1994-01-01

    As turbine-engine core operating conditions become more severe, designers must develop more effective means of cooling blades and vanes. In order to design reliable, cooled turbine blades, advanced transient thermal calculation techniques are required. The TACT1 computer program was developed to perform transient and steady-state heat-transfer and coolant-flow analyses for cooled blades, given the outside hot-gas boundary condition, the coolant inlet conditions, the geometry of the blade shell, and the cooling configuration. TACT1 can analyze turbine blades, or vanes, equipped with a central coolant-plenum insert from which coolant-air impinges on the inner surface of the blade shell. Coolant-side heat-transfer coefficients are calculated with the heat transfer mode at each station being user specified as either impingement with crossflow, forced convection channel flow, or forced convection over pin fins. A limited capability to handle film cooling is also available in the program. The TACT1 program solves for the blade temperature distribution using a transient energy equation for each node. The nodal energy balances are linearized, one-dimensional, heat-conduction equations which are applied at the wall-outer-surface node, at the junction of the cladding and the metal node, and at the wall-inner-surface node. At the mid-metal node a linear, three-dimensional, heat-conduction equation is used. Similarly, the coolant pressure distribution is determined by solving the set of transfer momentum equations for the one-dimensional flow between adjacent fluid nodes. In the coolant channel, energy and momentum equations for one-dimensional compressible flow, including friction and heat transfer, are used for the elemental channel length between two coolant nodes. The TACT1 program first obtains a steady-state solution using iterative calculations to obtain convergence of stable temperatures, pressures, coolant-flow split, and overall coolant mass balance. Transient

  12. Seal and bearing arrangement for use in a nuclear reactor

    International Nuclear Information System (INIS)

    Kazan, J.M.; Ritz, W.C.; Sharbaugh, J.E.

    1982-01-01

    A combination seal and bearing arrangement for use in a nuclear reactor including a vessel and vessel cover is disclosed herein. The vessel cover itself includes at least one rotatable plug which serves to perform certain position related functions within the reactor vessel and the combination seal and bearing arrangement is provided for sealing the annular opening around the rotation plug while, at the same time, providing a bearing support for the latter

  13. The Implications of Flexible Staffing Arrangements for Job Stability

    OpenAIRE

    Houseman, Susan N.; Polivka, Anne E.

    1999-01-01

    In this paper, we examine the job stability of workers in a wide range of flexible staffing arrangements: agency temporary, direct-hire temporary, on-call, contract company, independent contractor, and regular part-time work. We draw upon two data sources in our analysis. The first is a nationwide survey of employers on their use of flexible staffing arrangements conducted by the Upjohn Institute for Employment Research. This survey provides evidence on why employers use various types of flex...

  14. Institutional arrangements of Currency Boards - Comparative Macroeconomic Analysis

    OpenAIRE

    Lubomira Anastassova

    1999-01-01

    This paper is concentrated on the comparative macroeconomic analysis of the differences stemming from the extent to which the institutional framework of the currency board arrangement is implemented in the legal and regulatory systems in the different countries. The main objective of taking into consideration and examining the currency board institutional arrangements is to distinguish between the impact that currency board countries and countries with pegged exchange rate have on different m...

  15. Living arrangements in Western Europe: does cultural origin matter?

    OpenAIRE

    Giuliano, Paola

    2006-01-01

    Why are there such large differences in living arrangements across Western European countries? Conventional economic analyses have not been successful in explaining differences in living arrangements and particularly the dramatic increase in the fraction of young adults living with their parents in Mediterranean Europe. This paper presents a cultural interpretation. I argue that the sexual revolution of the 1970s - by liberalizing parental attitudes - had a differential impact on living arran...

  16. National arrangements for incidents involving radioactivity (NAIR) 1982/83

    International Nuclear Information System (INIS)

    Roberts, G.C.

    1984-01-01

    A summary is presented of the data on incidents notified under the National Arrangements for Incidents involving Radioactivity (NAIR), extending the data previously reported to include information for 1982/83. The categories of incidents discussed include transport, damaged sources or containers, undamaged sources, empty containers found and hoaxes or false alarms. It is concluded that the Arrangements continue to demonstrate their value in minimizing the alarm potentially inherent in even minor incidents involving radioactive materials. (U.K.)

  17. Innovative Nuclear Power Plant Building Arrangement in Consideration of Decommissioning

    OpenAIRE

    Won-Jun Choi; Myung-Sub Roh; Chang-Lak Kim

    2017-01-01

    A new concept termed the Innovative Nuclear Power Plant Building Arrangement (INBA) strategy is a new nuclear power plant building arrangement method which encompasses upfront consideration of more efficient decommissioning. Although existing decommissioning strategies such as immediate dismantling and differed dismantling has the advantage of either early site restoration or radioactive decommissioning waste reduction, the INBA strategy has the advantages of both strategies. In this research...

  18. Labour Arrangements in Cassava Production in Oyo State, Nigeria

    Directory of Open Access Journals (Sweden)

    Abila, N.

    2012-01-01

    Full Text Available The study examined the effects of labour arrangements on the profitability of cassava enterprises in Oyo North Area of Oyo State, Nigeria. A multi-stage sampling technique was adopted for data collection, while data were analysed using descriptive statistics and budgetary analysis. The results show that the prevalent labour arrangements for cassava enterprises are: a combination of Family, Hired and Contract labour (38.9%; Family-Hired labour (27.8%; Family-Contract labour (31.1%. The gross margin per hectares across labour arrangements are N279481.99 (all-labour, N286044.24 (family-hired, N216940.10 (familycontract, and N235000.00 (family only. The returns on a naira invested on variable costs across different labour arrangements for cassava enterprises are N2.04 (all-labour, N3.66 (family-hired, N2.37 (familycontract, and N2.61 (family only. This implies that a unit (N1 variable cost in the various labour arrangements of all-labour, family/hired, family/contract and family only in cassava production will yield a marginal return of N3.04, N3.66, N2.37 and N2.61 respectively. Family-hired labour arrangement yields higher marginal return per unit of manday and one naira spent than all other arrangements. The study recommends among others the application of laboursaving technologies and an optimum combination of various labour arrangements to reduce the cost of labour used in cassava production.

  19. Investigation of the Optimal Omni-Direction-Guide-Vane Design for Vertical Axis Wind Turbines Based on Unsteady Flow CFD Simulation

    Directory of Open Access Journals (Sweden)

    Behzad Shahizare

    2016-03-01

    Full Text Available With soaring energy demands, the desire to explore alternate and renewable energy resources has become the focal point of various active research fronts. Therefore, the scientific community is revisiting the notion to tap wind resources in more rigorous and novel ways. In this study, a two-dimensional computational investigation of the vertical axis wind turbine (VAWT with omni-direction-guide-vane (ODGV is proposed to determine the effects of this guide vane. In addition, the mesh and time step (dt size dependency test, as well as the effect of the different turbulence models on results accuracy are investigated. Eight different shape ratios (R of the omni-direction-guide-vane were also examined in this study. Further, the CFD model is validated by comparing the numerical results with the experimental data. Validation results show a good agreement in terms of shape and trend in CFD simulation. Based on these results, all the shape ratios, except two ratios including 0.3 and 0.4 at TSR of 1.3 to 3, have a positive effect on the power and torque coefficient improvement. Moreover, results show that the best case has a shape ratio of 0.55, which improves the power coefficient by 48% and the torque coefficient up to 58%.

  20. Influence of steam leakage through vane, gland, and shaft seals on rotordynamics of high-pressure rotor of a 1,000 MW ultra-supercritical steam turbine

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, P.N. [Shanghai Jiao Tong University, Key Laboratory of Power Machinery and Engineering, Ministry of Education, School of Mechanical Engineering, Shanghai (China); Shanghai Turbine Company, Department of R and D, Shanghai (China); Wang, W.Z.; Liu, Y.Z. [Shanghai Jiao Tong University, Key Laboratory of Power Machinery and Engineering, Ministry of Education, School of Mechanical Engineering, Shanghai (China); Meng, G. [Shanghai Jiao Tong University, State Key Laboratory of Mechanical System and Vibration, School of Mechanical Engineering, Shanghai (China)

    2012-02-15

    A comparative analysis of the influence of steam leakage through vane, gland, and shaft seals on the rotordynamics of the high-pressure rotor of a 1,000 MW ultra-supercritical steam turbine was performed using numerical calculations. The rotordynamic coefficients associated with steam leakage through the three labyrinth seals were calculated using the control-volume method and perturbation analysis. A stability analysis of the rotor system subject to the steam forcing induced by the leakage flow was performed using the finite element method. An analysis of the influence of the labyrinth seal forcing on the rotordynamics was carried out by varying the geometrical parameters pertaining to the tooth number, seal clearance, and inner diameter of the labyrinth seals, along with the thermal parameters with respect to pressures and temperatures. The results demonstrated that the steam forcing with an increase in the length of the blade for the vane seal significantly influences the rotordynamic coefficients. Furthermore, the contribution of steam forcing to the instability of the rotor is decreased and increased with increases in the seal clearance and tooth number, respectively. The comparison of the rotordynamic coefficients associated with steam leakage through the vane seal, gland seal, and shaft seal convincingly disclosed that, although the steam forcing attenuates the stability of the rotor system, the steam turbine is still operating under safe conditions. (orig.)

  1. Study on Pole Arrangement of the CEDM Coils

    International Nuclear Information System (INIS)

    Park, Jin Seok; Lee, Myoung Goo; Kim, Hyun Min; Cho, Yeon Ho; Choi, Taek Sang

    2013-01-01

    The coil stack assembly is important for reliable operation of the CEDM, there have been efforts to improve the design by optimizing the design parameters such as dimensions and winding turns. However, magnetic forces of the CEDM can also change by different pole arrangement even if their design parameters are the same. Since the latch coil and lift coil are installed connected to each other, they produce magnetically coupled field when they are energized at the same time. This coupling field can affect the magnetic force of the CEDM significantly. In this paper, coil pole arrangement effects are studied. Electro-magnetic analysis is performed for the different pole arrangements of the CEDM coils to calculate the magnetic forces. Pole arrangement effects on magnetic forces were studied by static analysis of the CEDM magnetic field. Magnetic forces were calculated and compared for the two different pole arrangements of the coils. The results show that the magnetic poles of the lift coil and latch coil shall be arranged to have the same magnetic pole direction to achieve higher magnetic force

  2. Living Arrangements and Suicidal Ideation among the Korean Elderly

    Science.gov (United States)

    Kim, Jibum; Lee, Yun-Suk; Lee, Jinkook

    2016-01-01

    Objectives This study examines how living arrangements are associated with suicidal ideation for older adults in South Korea, which has the highest suicide rate among OECD countries, and a particularly high suicide rate for older persons. Methods Analyzing a sample of 5,795 women and 3,758 men aged 65 and older from a nationwide representative cross-sectional data set, we examined how many older adults think about suicide over a one-year period, why they think about suicide, and whether living arrangements are associated with suicidal ideation. Results About one out of twelve respondents in our sample reported suicidal ideation. While women and men did not differ in the prevalence of suicidal ideation, women attributed their suicidal feelings to health problems, while men attributed theirs to economic difficulties. Logistic regression results indicated that living arrangements are associated with suicidal ideation for men but not women. Older men living with a spouse were less likely to have suicidal ideation than older men with other living arrangements (i.e., living alone, living with children without spouse, living with spouse and others). Conclusions Our results highlight the importance of living arrangements to older men’s suicidal ideation. We discuss gender differences in the implications of living arrangements to suicidal ideation within the context of Confucian culture. PMID:26317145

  3. Living arrangements and suicidal ideation among the Korean older adults.

    Science.gov (United States)

    Kim, Jibum; Lee, Yun-Suk; Lee, Jinkook

    2016-12-01

    This study examines how living arrangements are associated with suicidal ideation for older adults in South Korea, which has the highest suicide rate among OECD countries, and a particularly high suicide rate for older persons. Analyzing a sample of 5795 women and 3758 men aged 65 and older from a nationwide representative cross-sectional data-set, we examined how many older adults think about suicide over a one-year period, why they think about suicide, and whether living arrangements are associated with suicidal ideation. About 1 out of 12 respondents in our sample reported suicidal ideation. While women and men did not differ in the prevalence of suicidal ideation, women attributed their suicidal feelings to health problems, while men attributed theirs to economic difficulties. Logistic regression results indicated that living arrangements are associated with suicidal ideation for men but not women. Older men living with a spouse were less likely to have suicidal ideation than older men with other living arrangements (i.e., living alone, living with children without spouse, living with spouse, and others). Our results highlight the importance of living arrangements to older men's suicidal ideation. We discuss gender differences in the implications of living arrangements to suicidal ideation within the context of Confucian culture.

  4. Rotation induced flow suppression around two tandem circular cylinders at low Reynolds number

    Energy Technology Data Exchange (ETDEWEB)

    Chatterjee, Dipankar [Advanced Design and Analysis Group, CSIR—Central Mechanical Engineering Research Institute, Durgapur-713209 (India); Gupta, Krishan [Department of Mechanical Engineering, Sardar Vallabhai National Institute of Technology Surat, Surat-395007 (India); Kumar, Virendra [Department of Mechanical Engineering, Indian Institute of Technology Patna, Patna-800013 (India); Varghese, Sachin Abraham, E-mail: d_chatterjee@cmeri.res.in [Department of Mechanical Engineering, National Institute of Technology Durgapur, Durgapur-713209 (India)

    2017-08-15

    The rotation to a bluff object is known to have a stabilizing effect on the fluid dynamic transport around the body. An unsteady periodic flow can be degenerated into a steady flow pattern depending on the rate of rotation imparted to the body. On the other hand, multiple bodies placed in tandem arrangement with respect to an incoming flow can cause destabilization to the flow as a result of the complicated wake interaction between the bodies. Accordingly, the spacing between the bodies and the rate of rotation have significant impact on the overall fluid dynamic transport around them. The present work aims to understand how these two competing factors are actually influencing the fluidic transport across a pair of identical rotating circular cylinders kept in tandem arrangement in an unconfined medium. The cylinders are subjected to a uniform free stream flow and the gaps between the cylinders are varied as 0.2, 0.7, 1.5 and 3.0. Both the cylinders are made to rotate in the clockwise sense. The Reynolds number based on the free stream flow is taken as 100. A two-dimensional finite volume based transient computation is performed for a range of dimensionless rotational speeds of the cylinders (0 ≤ Ω ≤ 2.75). The results show that the shedding phenomena can be observed up to a critical rate of rotation (Ω{sub cr}) depending on the gap spacing. Beyond Ω{sub cr}, the flow becomes stabilized and finally completely steady as Ω increases further. Increasing the gap initially causes a slight decrease in the critical rotational speed, however, it increases at a rapid rate for larger gap spacing. (paper)

  5. Application of tandem accelerator mass spectrometor to the chronological study of archaeological samples on Ryukyu Islands

    International Nuclear Information System (INIS)

    Taira, Hatsuo; Higa, Kenichi; Nakai, Nobuyuki; Nakamura, Toshio.

    1987-01-01

    Along with the urbanization of rural areas on Ryukyu Islands, many shell mounds and pre-historic sites have been found in resent years. Chrological studies of shell samples from these mounds will lead to the better understanding of cultural background for the pre-historic human activities on the Ryukyu Islands. C-14 dating by beta counting is the common method to obtain the ages of the archaeological samples. It is, however, very limitted in obtaining the absolute ages by the above mehtod due to the large sample sizes required and time consuming. There are many newly obtained archaeological samples left unstudied in detail. The alternate is a method called Tandem Accelerator Mass Spectrometer (AMS) installed at Nagoya University, which is composed of the tandem type accelerator to measure very low concentration of C-14 in archaeological samples. The system has been designed particularly to measure the radio-carbon and has advantages of being small sample size and very little time consuming for C-14 measurement as compared with the beta counting. It is the aim of this work to apply the above AMS for obtaining the absolute ages of the archaeological samples. The results agreed well with those estimated by the Erthenware method (relative method of dating), which ranged from 500 to 6000 y.b.p. The results may be helpful for the chronological arrangement of the samples and for the understanding of pre-historical human activities on the Ryukyu Islands. (author)

  6. Radioisotope detection with tandem electrostatic accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Gove, H E; Elmore, D; Ferraro, R [Rochester Univ., NY (USA). Nuclear Structure Research Lab.; Beukens, R P; Chang, K H; Kilius, L R; Lee, H W; Litherland, A E [Toronto Univ., Ontario (Canada). Dept. of Physics; Purser, K H [General Ionex Corp., Newburyport, MA (USA)

    1980-01-01

    An MP tandem Van de Graaff accelerator at the University of Rochester has been employed since May 1977 to detect /sup 14/C in terrestrial samples, /sup 36/Cl in terrestrial and extraterrestrial samples and /sup 10/Be and /sup 26/Al in samples produced by reactor and accelerator irradiation. The sample sizes ranged from about 10 to less than 1 mg and the ratio of the radioisotope to the stable isotopes approached one part in 10/sup 16/ for /sup 14/C and /sup 36/Cl and one part in 10/sup 14/ for /sup 10/Be and /sup 26/Al. /sup 14/C has been measured in a number of samples of geological and archaelogical interest. /sup 36/Cl has been measured in various groundwater samples as well as samples at Antarctic meteorites and ice. Dedicated systems for /sup 14/C dating and geological measurements based on the tandem electrostatic accelerator principle are presently under construction for laboratories in the U.S.A., U.K. and Canada.

  7. Progress in the tandem mirror program

    International Nuclear Information System (INIS)

    Fowler, T.K.; Borchers, R.R.

    1981-01-01

    Experimental results in TMX have confirmed the basic principles of the tandem-mirror concept. A center-cell particle confinement parameter eta tau approx. 10 11 cm -3 s has been obtained at ion temperatures around 100 eV, which is a hundred-fold improvement over single mirrors at the same temperatures. For TMX these results have been obtained at peak beta values in the center cell in the range 10 to 40%, not yet limited by MHD activity; and ion-cyclotron resonant heating (ICRH) in the Phaedrus tandem-mirror experiment has produced beta values approx. 25%, which is several times the ideal MHD limit for that device. In addition, it has been demonstrated that the end fan chambers of TMX simultaneously isolate the hot electrons from the end walls, provide adequate pumping and conveniently dispose of the exhaust plasma energy either by thermal deposition on the end wall or by direct conversion to electricity (at 48% efficiency in agreement with calculations). Also, evidence was obtained for inherent divertor action in TMX, presumably in part responsible for the observed low impurity level

  8. Remote maintenance of tandem mirror hybrid coils

    International Nuclear Information System (INIS)

    Dietz, L.P.

    1983-01-01

    Hybrid Coils (superconducting coils with normal conducting inserts) are being employed with increasing frequency on Tandem Mirror Devices to obtain high field strengths. The normal conducting copper inserts are short lived in comparison to their encircling superconductors. It becomes desirable, therefore, to devise design features and maintenance procedures to replace the inner normal conducting coils without simultaneously replacing the longer lived (and significantly more costly) superconducting coils. The high neutron wall loadings require that the task be accomplished by remote control. The approach is to permanently mount the coil assemblies on track mounted carriages which serve, during machine operation merely as structural supports, but during maintenance procedures as moveable transport devices. The carriages incorporate all necessary provisions to facilitate remote maintenance operations and to adjust and align the coil assemblies with respect to adjacent machine components. The vacuum vessel is severed on both sides of the hybrid coil by means of a remote cutting machine. The entire coil is transported horizontally, normal to the machine axis to a nearby repair station. Prepositioned carriage mounted repair equipment at the repair station withdraws the damaged normal coil as a single entity and inserts a preassembled spare unit. The repaired hybrid coil is reassembled to the reactor. A cost and risk effective procedure has been evolved to maintain one of the more critical components of a Tandem Mirror Machine

  9. Preparation, melting behavior and thermal stability of poly(lactic acid)/poly(propylene carbonate) blends processed by vane extruder

    Energy Technology Data Exchange (ETDEWEB)

    Zou, Wei, E-mail: zw55624@163.com; Chen, Rongyuan; Zhang, Haichen; Qu, Jinping, E-mail: jpqu@scut.edu.cn [National Engineering Research Center of Novel Equipment for Polymer Processing, South China University of Technology, Guangzhou 510640 (China)

    2016-03-09

    Poly (lactic acid) (PLA)/Poly (propylene carbonate) (PPC) blends were prepared by vane extruder which is a type of novel polymer processing extruder based on elongation force field. Scanning electron microscope (SEM), differential scanning calorimetry (DSC) and thermogravimetric (TG) were used respectively to analyze the compatibility, the melting behavior and thermal stability properties of PLA/PPC blends affected by the different content of PPC. The results showed that with the increase of the PPC content, the glass transition temperature of PLA was reduced, and the glass transition temperature of PPC was increased, which indicated that PLA and PPC had partial compatibility. The cold crystallization temperature of PLA increased with the increase of the PPC content, which showed that PPC hindered the cold crystallization process of PLA. The addition of PPC had little impact on the melting process of PLA, and the melting temperature of PLA was almost kept the same value. Thermogravimetric analysis showed that the thermal stability of PPC was worse than that of PLA, the addition of PPC reduced the thermal stability of PLA.

  10. Improvement of the efficiency of the Agnew micro hydro turbine at part loads due to installing guide vanes mechanism

    Energy Technology Data Exchange (ETDEWEB)

    Yassi, Yousef; hashemloo, Safar [Iranian Research Organization for Science and Technology (IROST), No. 29 Forssat St., Enghelaab Ave., Tehran (Iran)

    2010-10-15

    Agnew turbine is an axial micro hydro of Kaplan type, with its main shaft subtending 45 to the line of horizon. Due to governmental power generating programs for limited hydro potentials in Iran and on the basis of a joint project between the University of Glasgow and the Iranian Research Organization for Science and Technology (IROST), the turbine was developed to operate under low heads and limited flow potentials in Iran. However the turbine was originally designed to operate without any guide vanes and test results showed that the turbine achieved an efficiency of 62% at its best point of performance. Later a modified Agnew turbine, consisting of a guide blades mechanism was designed and manufactured, at (IROST). The mechanism was so designed that it was also used as a second support for the turbine's main shaft. The standard turbine tests proved that; the modified version of the Agnew turbine had 23% higher efficiency at its best performance point; compared to the original design. Then the effects of the improvements on the turbine were studied on the performance of the turbine at part loads. However, efficiency improvements were observed under all part load conditions. (author)

  11. Improvement of the efficiency of the Agnew micro hydro turbine at part loads due to installing guide vanes mechanism

    International Nuclear Information System (INIS)

    Yassi, Yousef; Hashemloo, Safar

    2010-01-01

    Agnew turbine is an axial micro hydro of Kaplan type, with its main shaft subtending 45 deg. to the line of horizon. Due to governmental power generating programs for limited hydro potentials in Iran and on the basis of a joint project between the University of Glasgow and the Iranian Research Organization for Science and Technology (IROST), the turbine was developed to operate under low heads and limited flow potentials in Iran. However the turbine was originally designed to operate without any guide vanes and test results showed that the turbine achieved an efficiency of 62% at its best point of performance. Later a modified Agnew turbine, consisting of a guide blades mechanism was designed and manufactured, at (IROST). The mechanism was so designed that it was also used as a second support for the turbine's main shaft. The standard turbine tests proved that; the modified version of the Agnew turbine had 23% higher efficiency at its best performance point; compared to the original design. Then the effects of the improvements on the turbine were studied on the performance of the turbine at part loads. However, efficiency improvements were observed under all part load conditions.

  12. Simulation of performance of centrifugal circulators with vane-less diffuser for GCR applications - HTR2008-58166

    International Nuclear Information System (INIS)

    Tauveron, N.

    2008-01-01

    In the frame of the international forum Gen lV, CEA has selected various innovative concepts of Gas cooled Nuclear Reactor. Among them, an indirect-cycle gas reactor is under consideration. Thermal hydraulic performances are a key issue for the design. For transient conditions and decay heat removal situations, the thermal hydraulic performance must remain as high as possible. In this context, all the transient situations, the incidental and accidental scenarios must be evaluated by a validated sys-tem code able to correctly describe, in particular, the thermal-hydraulics of the whole plant. As concepts use a helium compressor to maintain the flow in the core, a special emphasis must be laid on compressor modelling. Centrifugal circulators with a vane-less diffuser have significant properties in term of simplicity, cost, ability to operate over a wide range of conditions. The objective of this paper is to present a dedicated description of centrifugal compressor, based on a one dimensional approach. This type of model requires various correlations as input data. The present contribution consists in establishing and validating the numerical simulations (including different sets of correlations) by comparison with representative experimental data. The results obtained show a qualitatively correct behaviour of the model compared to open literature cases of the gas turbine aircraft community and helium circulators of High Temperature Gas Reactors. Further work on modelling and validation are nevertheless needed to have a better confidence in the simulation predictions. (authors)

  13. Computational study: The influence of omni-directional guide vane on the flow pattern characteristic around Savonius wind turbine

    Science.gov (United States)

    Wicaksono, Yoga Arob; Tjahjana, D. D. D. P.

    2017-01-01

    Standart Savonius wind turbine have a low performance such as low coefficient of power and low coefficient of torque compared with another type of wind turbine. This phenomenon occurs because the wind stream can cause the negative pressure at the returning rotor. To solve this problem, standard Savonius combined with Omni Directional Guide Vane (ODGV) proposed. The aim of this research is to study the influence of ODGV on the flow pattern characteristic around of Savonius wind turbine. The numerical model is based on the Navier-Stokes equations with the standard k-ɛ turbulent model. This equation solved by a finite volume discretization method. This case was analyzed by commercial computational fluid dynamics solver such as SolidWorks Flow Simulations. Simulations were performed at the different wind directions; there are 0°, 30°,60° at 4 m/s wind speed. The numerical method validated with the past experimental data. The result indicated that the ODGV able to augment air flow to advancing rotor and decrease the negative pressure in the upstream of returning rotor compared to the bare Savonius wind turbine.

  14. Numerical study on dissimilar guide vane design with SCC piston for air and emulsified biofuel mixing improvement

    Directory of Open Access Journals (Sweden)

    Hamid Mohd Fadzli

    2017-01-01

    Full Text Available Crude palm oil (CPO is one of the most potential biofuels that can be applied in the conventional diesel engines, where the chemical properties of CPO are comparable to diesel fuel. However, its higher viscosity and heavier molecules can contributes to several engine problems such as low atomization during injection, carbon deposit formation, injector clogging, low mixing with air and lower combustion efficiency. An emulsification of biofuel and modifications of few engine critical components have been identified to mitigate the issues. This paper presents the effects of dissimilar guide vane design (GVD in terms of height variation of 0.25R, 0.3R and 0.35R at the intake manifold with shallow depth re-entrance combustion chamber (SCC piston application to the incylinder air flow characteristics improvement. The simulation results show that the intake manifold with GVD improved the performance of the air flow characteristic particularly swirl, tumble and cross tumble ratios from the intake manifold to the engine. The GVD with the height of 0.3R was found to be the optimum design with respect to the overall improvement of the air flow characteristic. The improvement of the air flow characteristic with the application of GVD and SCC piston in the engine was expected to contribute to a better air fuel mixing, fuel atomization and combustion efficiency of the engine using emulsified biofuel as a source of fuel.

  15. Zero-gravity Mean Free Surface Curvature of a Confined Liquid in a Radially-Vaned Container

    Science.gov (United States)

    Chen, Yongkang; Callahan, Michael; Weislogel, Mark

    2013-01-01

    A variety of increasingly intricate container geometries are under consideration for the passive manipulation of liquids aboard spacecraft where the impact of gravity may be neglected. In this study we examine the mean curvature of a liquid volume confined within a radial array of disconnected vanes of infinite extent. This particular geometry possesses a number of desirable characteristics relevant to waste water treatment aboard spacecraft for life support. It is observed that under certain conditions the slender shape of the free surface approaches an asymptote, which can be predicted analytically using new hybrid boundary conditions proposed herein. This contribution represents possibly the final extension of what has been referred to as the method of de Lazzer et al. (1996). The method enables the integration of the Young-Laplace equation over a domain with its boundaries, including the wetted portion of the solid boundaries, symmetry planes, and circular arcs representing free surfaces at the center plane of the liquid body. Asymptotic solutions at several limits are obtained and the analysis is confirmed with numerical computations.

  16. Cavitation on a scaled-down model of a Francis turbine guide vane: high-speed imaging and PIV measurements

    Science.gov (United States)

    Pervunin, K. S.; Timoshevskiy, M. V.; Churkin, S. A.; Kravtsova, A. Yu; Markovich, D. M.; Hanjalić, K.

    2015-12-01

    Cavitation on two symmetric foils, a NACA0015 hydrofoil and a scaled-down model of a Francis turbine guide vane (GV), was investigated by high-speed visualization and PIV. At small attack angles the differences between the profiles of the mean and fluctuating velocities for both hydrofoils were shown to be insignificant. However, at the higher angle of incidence, flow separation from the GV surface was discovered for quasi-steady regimes including cavitation-free and cavitation inception cases. The flow separation leads to the appearance of a second maximum in velocity fluctuations distributions downstream far from the GV surface. When the transition to unsteady regimes occurred, the velocity distributions became quite similar for both foils. Additionally, for the GV an unsteady regime characterized by asymmetric spanwise variations of the sheet cavity length along with alternating periodic detachments of clouds between the sidewalls of the test channel was for the first time visualized. This asymmetric behaviour is very likely to be governed by the cross instability that was recently described by Decaix and Goncalvès [8]. Moreover, it was concluded that the existence of the cross instability is independent on the test body shape and its aspect ratio.

  17. Effects of grid spacer with mixing vane on entrainments and depositions in two-phase annular flows

    Directory of Open Access Journals (Sweden)

    Akimaro Kawahara

    2015-06-01

    Full Text Available The effects of mixing vanes (MVs attached to a grid spacer on the characteristics of air–water annular flows were experimentally investigated. To know the effects, a grid spacer with or without MV was inserted in a vertical circular pipe of 16-mm internal diameter. For three cases (i.e., no spacer, spacer without MV, and spacer with MV, the liquid film thickness, liquid entrainment fraction, and deposition rate were measured by the constant current method, single liquid film extraction method, and double liquid film extraction method, respectively. The MVs significantly promote the re-deposition of liquid droplets in the gas core flow into the liquid film on the channel walls. The deposition mass transfer coefficient is three times higher for the spacer with MV than for the spacer without MV, even for cases 0.3-m downstream from the spacer. The liquid film thickness becomes thicker upstream and downstream for the spacer with MV, compared with the thickness for the spacer without MV and for the case with no spacer.

  18. Negotiating Multiple Identities through eTandem Learning Experiences

    Science.gov (United States)

    Yang, Se Jeong; Yi, Youngjoo

    2017-01-01

    Much of eTandem research has investigated either linguistic or cross-cultural aspects of second language (L2) learning, but relatively little is known about issues of identity construction in an eTandem context. Situating the study within theories and research of language learner identity, we examined ways in which two adult L2 learners (a Korean…

  19. Recent improvements of the tandem facility at LNS

    International Nuclear Information System (INIS)

    Ciavola, G.; Calabretta, L.; Cuttone, G.; Gammino, S.; Raia, G.; Rifuggiato, D.; Rovelli, A.; Scuderi, V.

    1993-01-01

    The Laboratorio Nazionale del Sud (LNS) of Catania is equipped with an upgraded 15 MV SMP tandem that is going to be coupled to a k=800 superconducting cyclotron. The status of the facility and the performances of the upgraded tandem are presented. (orig.)

  20. Status report on the folded tandem ion accelerator at BARC

    Indian Academy of Sciences (India)

    Folded tandem ion accelerator; charged particle beams; voltage stability; Rutherford backscattering; ion optics; beam lines. Abstract. The folded tandem ion accelerator (FOTIA) facility set up at BARC has become operational. At present, it is used for elemental analysis studies using the Rutherford backscattering technique.

  1. High-sensitivity mass spectrometry with a tandem accelerator

    International Nuclear Information System (INIS)

    Henning, W.

    1984-01-01

    The characteristic features of accelerator mass spectrometry are discussed. A short overview is given of the current status of mass spectrometry with high-energy (MeV/nucleon) heavy-ion accelerators. Emphasis is placed on studies with tandem accelerators and on future mass spectrometry of heavier isotopes with the new generation of higher-voltage tandems

  2. Performance analysis of tandem queues with small buffers

    NARCIS (Netherlands)

    Vuuren, van M.; Adan, I.J.B.F.; Papadopoulos, C.T.

    2005-01-01

    In this paper we present an approximation for the performance analysis of single-server tandem queues with small buffers and generally distributed service times. The approximation is based on decomposition of the tandem queue in subsystems, the parameters of which are determined by an iterative

  3. A solution process for inverted tandem solar cells

    DEFF Research Database (Denmark)

    Larsen-Olsen, Thue Trofod; Bundgaard, Eva; Sylvester-Hvid, Kristian O.

    2011-01-01

    Tandem solar cells with normal and inverted device geometries were prepared by a solution process. Both device types were based on the use of zinc(II)oxide as the electron transporting layer (ETL). The hole transporting layer (HTL) was either PEDOT:PSS for normal geometry tandem solar cells...... or vanadium(V)oxide in the case of inverted tandem cells. It was found that the inverted tandem solar cells performed comparable or better than the normal geometry devices, showing that the connection structure of vanadium(V)oxide, Ag nanoparticles and zinc(II)oxide functions both as a good recombination...... layer, ensuring serial connection, and as a solvent barrier, protecting the first photoactive layer from processing of the second layer. This successfully demonstrates a tandem solar cell fabrication process fully compatible with state-of-the-art solution based automated production procedures....

  4. New arrangement for the air cleanup system to recover tritium

    International Nuclear Information System (INIS)

    Nishikawa, Masabumi; Takahashi, Kohsaku; Munakata, Kenzo; Fukada, Satoshi; Kotoh, Kenji; Takeishi, Toshiharu

    1997-01-01

    At present, the standard arrangement of the air cleanup system responsible for emergency tritium recovery from room air is a catalytic oxidation bed with a heater followed by an adsorption bed with a cooler. One disadvantage of this arrangement is that trouble with the heater or the cooler could result in a loss of capacity to recover tritium. Another disadvantage of the catalyst-adsorption-bed arrangement is that tritiated water must be recovered with a high decontamination factor after dilution with a large amount of water vapor in the working atmosphere. The performance of a new arrangement for the air cleanup system, which consists of a precious metal catalyst bed preceded by an adsorption bed without heating equipment, is discussed. According to calculations, most of the tritium released to the room air is recovered in the catalyst bed through oxidation, adsorption, and isotope exchange reaction when the new arrangement is applied. The adsorption bed placed before the catalyst bed dehumidifies the process gas to such a degree that the oxidation reaction of tritium in the catalyst bed is not hindered by water vapor. 15 refs., 6 figs., 6 tabs

  5. Role of crystal arrangement on the mechanical performance of enamel.

    Science.gov (United States)

    An, Bingbing; Wang, Raorao; Zhang, Dongsheng

    2012-10-01

    The superior mechanical properties of enamel, such as excellent penetration and crack resistance, are believed to be related to the unique microscopic structure. In this study, the effects of hydroxyapatite (HAP) crystallite orientation on the mechanical behavior of enamel have been investigated through a series of multiscale numerical simulations. A micromechanical model, which considers the HAP crystal arrangement in enamel prisms, the hierarchical structure of HAP crystals and the inelastic mechanical behavior of protein, has been developed. Numerical simulations revealed that, under compressive loading, plastic deformation progression took place in enamel prisms, which is responsible for the experimentally observed post-yield strain hardening. By comparing the mechanical responses for the uniform and non-uniform arrangement of HAP crystals within enamel prisms, it was found that the stiffness for the two cases was identical, while much greater energy dissipation was observed in the enamel with the non-uniform arrangement. Based on these results, we propose an important mechanism whereby the non-uniform arrangement of crystals in enamel rods enhances energy dissipation while maintaining sufficient stiffness to promote fracture toughness, mitigation of fracture and resistance to penetration deformation. Further simulations indicated that the non-uniform arrangement of the HAP crystals is a key factor responsible for the unique mechanical behavior of enamel, while the change in the nanostructure of nanocomposites could dictate the Young's modulus and yield strength of the biocomposite. Copyright © 2012 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  6. TMX-U [Tandem Mirror Experiment-Upgrade] tandem-mirror thermal-barrier experiments

    International Nuclear Information System (INIS)

    Simonen, T.C.; Allen, S.L.; Baldwin, D.E.

    1986-01-01

    Thermal-barrier experiments have been carried out in the Tandem Mirror Experiment-Upgrade (TMX-U). Measurements of nonambipolar and ambipolar radial transport show that these transport processes, as well as end losses, can be controlled at modest densities and durations. Central-cell heating methods using ion-cyclotron heating (ICH) and neutral-beam injection have been demonstrated. Potential mesurements with recently developed methods indicate that deep thermal barriers can be established

  7. Prospects for a DD tandem mirror

    International Nuclear Information System (INIS)

    Logan, B.G.

    1977-01-01

    The possibility of burning advanced fusion fuels in a tandem mirror is considered for a catalyzed DD cycle, in which the T and 3 He reaction products from DD burn in both the solenoid and plugs are reinjected for complete burnup: 3D → p + 4 He + n + 21.6 MeV. Classical radial transport of the 4 He ash determines the steady state alpha fraction in the solenoid. Synchrotron radiation losses are minimized at high beta, such that charged particle fusion power recovered in a direct converter exceeds radiation losses by a factor greater than two. An overall system Q = 4.5 is found for one reaction example but the power output is large (3 GE(e) net) due to the low power density in the solenoid. Optimizing recirculating power cost (Q) against plug/solenoid density ratio (power density) should result in much smaller reactor size and cost

  8. Folded tandem ion accelerator facility at BARC

    International Nuclear Information System (INIS)

    Agarwal, Arun; Padmakumar, Sapna; Subrahmanyam, N.B.V.; Singh, V.P.; Bhatt, J.P.; Ware, Shailaja V.; Pol, S.S; Basu, A.; Singh, S.K.; Krishnagopal, S.; Bhagwat, P.V.

    2017-01-01

    The 5.5 MV single stage Van de Graaff (VDG) accelerator was in continuous operation at Nuclear Physics Division (NPD), Bhabha Atomic Research Centre (BARC) since its inception in 1962. During 1993-96, VDG accelerator was converted to a Folded Tandem Ion Accelerator (FOTIA). The scientists and engineers of NPD, IADD (then a part of NPD) along with several other divisions of BARC joined hands together in designing, fabrication, installation and commissioning of the FOTIA for the maximum terminal voltage of 6 MV. After experiencing the first accelerated ion beam on the target from FOTIA during April 2000, different ion species were accelerated and tested. Now this accelerator FOTIA is in continuous use for different kind of experiments

  9. Educational activities with a tandem accelerator

    Science.gov (United States)

    Casolaro, P.; Campajola, L.; Balzano, E.; D'Ambrosio, E.; Figari, R.; Vardaci, E.; La Rana, G.

    2018-05-01

    Selected experiments in fundamental physics have been proposed for many years at the Tandem Accelerator of the University of Napoli ‘Federico II’s Department of Physics as a part of a one-semester laboratory course for graduate students. The aim of this paper is to highlight the educational value of the experimental realization of the nuclear reaction 19F(p,α)16O. With the purpose of verifying the mass-energy equivalence principle, different aspects of both classical and modern physics can be investigated, e.g. conservation laws, atomic models, nuclear physics applications to compositional analysis, nuclear cross-section, Q-value and nuclear spectroscopic analysis.

  10. Tandem mirror reactor power balance studies

    International Nuclear Information System (INIS)

    Gorker, G.E.; Perkins, L.J.

    1985-01-01

    A tandem mirror reactor (TMR) power plant balance model has been developed and is now being used as a computer aid for performing parametric studies. End-cell power injection into the plasma and the physics thermal Q are used to determine the fusion power. About 80% of the fusion power is transferred by high-energy neutrons to the blanket modules and structures. The other 20% of the fusion power in the high-energy alpha particles is used to heat the deuterium-tritium (D-T) plasma. Most of the plasma-ionized particles transfer their energy to the halo dumps and direct converters. The plant efficiency is calculated for three different system cycles: (1) the pressurized water/saturated steam cycle; (2) the superheated steam cycle; and (3) the more complex superheat/reheat cycle. There is a signficiant improvement in plant efficiency as the electrical power multiplication factor and steam cycle efficiency increases

  11. Status of tandem-mirror confinement

    International Nuclear Information System (INIS)

    Baldwin, D.E.

    1983-01-01

    Recent end-stopping experiments in TMX-Upgrade show strong plugging of the central cell by lower-density plugs, requiring both electron-cyclotron heating (ECRH) and 47 0 neutral-beam injection, consistent with the thermal-barrier concept. These experiments have low density (n 12 cm -3 ) due to inefficient ECRH power coupling. Hot-ion and hot-electron buildup are consistent with Fokker-Planck calculations. No ion-cyclotron activity is observed in the plugs; occasional electron-cyclotron activity is observed. With plugging, axial lifetimes (tau/sub parallel/ > 40 ms) are larger than radial (tau/sub perpendicular/ = 5 to 10 ms) due to observed non-ambipolar ion transport. Recent tandem-mirror theoretical activities are also surveyed

  12. Do organizational and political-legal arrangements explain financial wrongdoing?

    Science.gov (United States)

    Prechel, Harland; Zheng, Lu

    2016-12-01

    The 2008 financial crisis was a systemic problem with deep-rooted structural causes that created opportunities to engage in financial malfeasance, a form of corporate wrongdoing. However, few quantitative studies exist on the effects of organizational and political-legal arrangements on financial malfeasance. In this paper, we examine the effects of organizational and political-legal arrangements that emerged in the 1990s in the FIRE sector (i.e., financial, insurance, and real estate) on financial malfeasance. Our historical contextualization demonstrates how changes in the political-legal arrangements facilitate the emergence of new corporate structures and opportunities for financial malfeasance. Our longitudinal quantitative analysis demonstrates that US FIRE sector corporations with a more complex organizational structure, larger size, lower dividend payment, and higher executive compensation are more prone to commit financial malfeasance. © London School of Economics and Political Science 2016.

  13. Emergency response arrangements for the transport of radioactive materials

    International Nuclear Information System (INIS)

    Morgan-Warren, E.

    2004-01-01

    Response arrangements are required for the transport of radioactive materials, under both transport and health and safety legislation, to safeguard persons, property and the environment in the event of incidents and emergencies. Responsibilities fall on both government and industry: government is responsible for ensuring public safety and providing information and reassurance. This responsibility is discharged for each type of incident by a nominated ''lead department'', supported as appropriate by other government departments and agencies; for their part, operators are obliged to have arrangements in place for dealing with the practicalities of any reasonably foreseeable incident, including recovery and onward transport of a package, and any required clean-up or restoration of the environment. This paper outlines both the government and industry arrangements in Great Britain. The principles of response and intervention are discussed, together with the lead department concept, regulatory requirements, and the plans developed by the transport industry to ensure a nation-wide response capability

  14. Patient sensing and indicating arrangement for a computed tomography system

    International Nuclear Information System (INIS)

    Barrett, D.M.

    1979-01-01

    An arrangement is provided for sensing and indicating if a cross section of a patient extends beyond an image reconstruction circle during examination. The arrangement is positioned within a generally vertical gantry having a generally cylindrical opening for receiving the patient. The arrangement includes a plurality of light emitting sources disposed within the gantry and which are closely adjacent the reconstruction circle. Each light emitting source projects a light beam along a line which is parallel with the plane of the reconstruction circle and tangent to a cylinder having a diameter and central axis in agreement with the reconstruction circle. The light beams extend substantially across the opening in the gantry and generally inscribe the reconstruction circle. A plurality of photodetectors are disposed within the gantry and aligned to receive each of the light beams. The photodetectors are interconnected to the system by means for indicating an interruption of any of the light beams between any of the sources and detectors

  15. Molecular ion acceleration using tandem accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Saito, Yuichi; Mizuhashi, Kiyoshi; Tajima, Satoshi [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment

    1996-12-01

    In TIARA compound beam radiation system, cluster beams have been produced using 3 MV tandem accelerator (9SDH-2) to supply them to various radiation on injection experiments. Till now, productions of C{sub 2-8}, Si{sub 2-4} and O{sub 2} and their accelerations up to 6 MeV have been succeeded. This study aimed at production and acceleration of B{sub 2-4} and LiF. Anion clusters were produced using the conventional ion source of cesium sputter type. The proportions of atoms, molecules and clusters elicited from the ion source were varied depending on the material`s properties and the operating conditions of ion source such as sample temperature, sputter voltage and the shape of sample. The anion clusters were accelerated toward the high voltage terminal in the center of tandem accelerator, leading to cations through losing their electrons by the collision to N{sub 2} gas in a charge conversion cell at the terminal. Positively charged cluster ions could be obtained by modulating the pressure of N{sub 2} gas. Thus, B{sub 2} (64 nA), B{sub 3} (4.4 nA) and B{sub 4} (2.7 nA) have been produced and their maximum survival probabilities were higher than those of carbon or silicon clusters. In addition, the relationship between beam current and gas pressure was investigated for Bn (n = 2-4) and LiF. (M.N.)

  16. 29 CFR 779.228 - Types of arrangements contemplated by exception.

    Science.gov (United States)

    2010-07-01

    ... Coverage Leased Departments, Franchise and Other Business Arrangements § 779.228 Types of arrangements... section 3(s) would not otherwise apply: (a) Any arrangement, whether by agreement, franchise or otherwise...

  17. Improvements in or relating to radiation detection arrangements

    International Nuclear Information System (INIS)

    Davis, G.P.

    1977-01-01

    A radiation detection arrangement is described that that comprises a number of scintillator devices, and a single multi-channel photomultiplier tube. Light from the scintillator devices is incident on the photocathode through an entrance window in the tube and multiplier entrance separating means are provided whereby light from each of the devices is made to be incident upon the channel entrances of photomultiplier tube. Various geometrical forms for the scintillator devices are described. This arrangement avoids the use of large number of small photomultiplier tubes, which is expensive and gives rise to difficulties in stacking the tubes in closely spaced side-by-side relationship. (U.K.)

  18. Six-strut arrangements for cartesian movements of mirrors

    International Nuclear Information System (INIS)

    Noll, T.; Zeschke, Th.; Reichardt, G.; Lammert, H.; Gudat, W.

    2001-01-01

    At BESSY a new six-strut arrangement for general small travel mirror adjustment mechanisms has been developed. This patented (Patent DE 10042802.5) arrangement allows very simple movements in all six linear and rotational degrees of freedom. The movements of the mirror are simply determined by moving either one drive, or up to three drives by the same amount. The first mirror adjustment systems of this design is successfully in operation since the start of BESSY II. Their performance and reliability is very satisfactory. This contribution will present the concepts

  19. Concepts for institutional arrangements for the nuclear fuel cycle

    International Nuclear Information System (INIS)

    1979-02-01

    These concepts deal with establishing a framework for the analysis of institutional arrangements, with institutional arrangements under consideration in the working groups on fuel and heavy water availability, enrichment availability, assurances of long-term supply, reprocessing-plutonium handling-recycling, fast breeder reactors, spent fuel management, waste management and disposal, and advanced reactor concepts. The standardization of nuclear practices, joint commercial and development undertakings, nuclear supply assurances, developing a consensus in international nuclear co-operation, and settlements of disputes are treated

  20. Editorial: Spatial arrangement of faults and opening-mode fractures

    Science.gov (United States)

    Laubach, Stephen E.; Lamarche, Juliette; Gauthier, Bertand D. M.; Dunne, William M.

    2018-03-01

    This issue of the Journal of Structural Geology titled Spatial arrangement of faults and opening-mode fractures explores a fundamental characteristic of fault and fracture arrays. The pattern of fault and opening-mode fracture positions in space defines structural heterogeneity and anisotropy in a rock volume, governs how faults and fractures affect fluid flow, and impacts our understanding of the initiation, propagation and interactions during the formation of fracture patterns. This special issue highlights recent progress with respect to characterizing and understanding the spatial arrangements of fault and fracture patterns, providing examples over a wide range of scales and structural settings.