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Sample records for current experimental conditions

  1. Wall conditioning for ITER: Current experimental and modeling activities

    Energy Technology Data Exchange (ETDEWEB)

    Douai, D., E-mail: david.douai@cea.fr [CEA, IRFM, Association Euratom-CEA, 13108 St. Paul lez Durance (France); Kogut, D. [CEA, IRFM, Association Euratom-CEA, 13108 St. Paul lez Durance (France); Wauters, T. [LPP-ERM/KMS, Association Belgian State, 1000 Brussels (Belgium); Brezinsek, S. [FZJ, Institut für Energie- und Klimaforschung Plasmaphysik, 52441 Jülich (Germany); Hagelaar, G.J.M. [Laboratoire Plasma et Conversion d’Energie, UMR5213, Toulouse (France); Hong, S.H. [National Fusion Research Institute, Daejeon 305-806 (Korea, Republic of); Lomas, P.J. [CCFE, Culham Science Centre, OX14 3DB Abingdon (United Kingdom); Lyssoivan, A. [LPP-ERM/KMS, Association Belgian State, 1000 Brussels (Belgium); Nunes, I. [Associação EURATOM-IST, Instituto de Plasmas e Fusão Nuclear, 1049-001 Lisboa (Portugal); Pitts, R.A. [ITER International Organization, F-13067 St. Paul lez Durance (France); Rohde, V. [Max-Planck-Institut für Plasmaphysik, 85748 Garching (Germany); Vries, P.C. de [ITER International Organization, F-13067 St. Paul lez Durance (France)

    2015-08-15

    Wall conditioning will be required in ITER to control fuel and impurity recycling, as well as tritium (T) inventory. Analysis of conditioning cycle on the JET, with its ITER-Like Wall is presented, evidencing reduced need for wall cleaning in ITER compared to JET–CFC. Using a novel 2D multi-fluid model, current density during Glow Discharge Conditioning (GDC) on the in-vessel plasma-facing components (PFC) of ITER is predicted to approach the simple expectation of total anode current divided by wall surface area. Baking of the divertor to 350 °C should desorb the majority of the co-deposited T. ITER foresees the use of low temperature plasma based techniques compatible with the permanent toroidal magnetic field, such as Ion (ICWC) or Electron Cyclotron Wall Conditioning (ECWC), for tritium removal between ITER plasma pulses. Extrapolation of JET ICWC results to ITER indicates removal comparable to estimated T-retention in nominal ITER D:T shots, whereas GDC may be unattractive for that purpose.

  2. Secondary current properties generated by wind-induced water waves in experimental conditions

    Directory of Open Access Journals (Sweden)

    Michio Sanjou

    2014-06-01

    Full Text Available Secondary currents such as the Langmuir circulation are of high interest in natural rivers and the ocean because they have striking impacts on scour, sedimentation, and mass transport. Basic characteristics have been well-studied in straight open-channel flows. However, little is known regarding secondary circulation induced by wind waves. The presented study describes the generation properties of wind waves observed in the laboratory tank. Wind-induced water waves are known to produce large scale circulations. The phenomenon is observed together with high-speed and low-speed streaks, convergence and divergence zones, respectively. Therefore, it is important to determine the hydrodynamic properties of secondary currents for wind-induced water waves within rivers and lakes. In this study, using two high-speed CMOS cameras, stereoscopic particle image velocimetry (PIV measurements were conducted in order to reveal the distribution of all three components of velocity vectors. The experiments allowed us to investigate the three-dimensional turbulent structure under water waves and the generation mechanism of large-scale circulations. Additionally, a third CMOS camera was used to measure the spanwise profile of thefree-surface elevation. The time-series of velocity components and the free-surface were obtained simultaneously. From our experiments, free-surface variations were found to influence the instantaneous velocity distributions of the cross-sectional plane. We also considered thegeneration process by the phase analysis related to gravity waves and compared the contribution of the apparent stress.

  3. Experimental Investigation of an Automobile Air-Conditioning System using Integrated Brushless Direct Current Motor Rotary Compressor

    Directory of Open Access Journals (Sweden)

    Sukri M.F.

    2016-01-01

    Full Text Available The present study presents an experimental investigation on the effect of condenser air inlet temperature and dimensionless parameter of X on the performance of automobile air-conditioning (AAC system using integrated brushless direct current motor-rotary compressor and electronic expansion valve. The other components of AAC system are from original component of AAC system used for medium size passenger car. The experimental results showed that the increment of the condenser air inlet temperature and X caused an increase in condensing temperature, cooling capacity and compressor work, while decreasing the coefficient of performance (COP. Meanwhile, the evaporating temperature increase with the increment of condenser air inlet temperature, but decrease with decrement of X. In general, AAC system have to work at higher value of X in order to produce more cooling capacity, thereby increment in compressor work also occurs due to energy balance. However, at higher value of X, the COP of the system dropped due to dominant increase in compressor power, as opposed to a rise in cooling capacity. Due to this reason, the best operation of this compressor occurs at X = 4.96 for constant T5 (35ºC, or at T5 = 30ºC for constant X (4.96.

  4. Minimum quench power dissipation and current non-uniformity in international thermonuclear experimental reactor type NbTi cable-in-conduit conductor samples under direct current conditions

    Science.gov (United States)

    Rolando, G.; van Lanen, E. P. A.; Nijhuis, A.

    2012-05-01

    The level of current non-uniformity in NbTi cable-in-conduit conductors (CICCs) sections near the joints in combination with the magnetic field profile needs attention in view of proper joint design. The strand joule power and current distribution at quench under DC conditions of two samples of ITER poloidal field coil conductors, as tested in the SULTAN facility, and of the so called PFCI model coil insert, have been analyzed with the numerical cable model JackPot. The precise trajectories of all individual strands, joint design, cabling configuration, spatial distribution of the magnetic field, sample geometry, and experimentally determined interstrand resistance distributions have been taken into account. Although unable to predict the quench point due to the lack of a thermal-hydraulic routine, the model allows to assess the instantaneous strand power at quench and its local distribution in the cable once the quench conditions in terms of current and temperature are experimentally known. The analysis points out the relation of the above mentioned factors with the DC quench stability of both short samples and coils. The possible small scale and local electrical-thermal interactions were ignored in order to examine the relevance of such effects in the overall prediction of the CICC performance. The electromagnetic code shows an excellent quantitative predictive potential for CICC transport properties, excluding any freedom for matching the results. The influence of the local thermal effects in the modeling is identified as being marginal and far less than the generally accepted temperature margin for safe operation.

  5. Experimental study on a wide range of wave and current conditions of the WEPTOS Wave Energy Converter

    DEFF Research Database (Denmark)

    Pecher, Arthur; Kofoed, Jens Peter

    This report presents the results of an experimental study that was performed on small scale model that was a replication of the full-scale Weptos WEC intended for DanWEC. The tests were performed in the circular basin at FloWave at Edinburgh University in October 2014. The laboratory facilities h...... the capabilities to have simultaneously currents and waves from any possible direction and also to produce advanced wave specifications....

  6. NOAA NOS SOS, EXPERIMENTAL - Currents

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NOAA NOS SOS server is part of the IOOS DIF SOS Project. The stations in this dataset have currents data. *These services are for testing and evaluation use...

  7. Top Quark Current Experimental Status

    CERN Document Server

    Juste, A

    2006-01-01

    Ten years after its discovery at the Tevatron collider, we still know little about the top quark. Its large mass suggests it may play a key role in the mechanism of Electroweak Symmetry Breaking (EWSB), or open a window of sensitivity to new physics related to EWSB and preferentially coupled to it. To determine whether this is the case, precision measurements of top quark properties are necessary. The high statistics samples being collected by the Tevatron experiments during Run II start to incisively probe the top quark sector. This report summarizes the experimental status of the top quark, focusing in particular on the recent measurements from the Tevatron.

  8. Gravity current jump conditions, revisited

    Science.gov (United States)

    Ungarish, Marius; Hogg, Andrew J.

    2016-11-01

    Consider the flow of a high-Reynolds-number gravity current of density ρc in an ambient fluid of density ρa in a horizontal channel z ∈ [ 0 , H ] , with gravity in - z direction. The motion is often modeled by a two-layer formulation which displays jumps (shocks) in the height of the interface, in particular at the leading front of the dense layer. Various theoretical models have been advanced to predict the dimensionless speed of the jump, Fr = U /√{g' h } ; g' , h are reduced gravity and jump height. We revisit this problem and using the Navier-Stokes equations, integrated over a control volume embedding the jump, derive balances of mass and momentum fluxes. We focus on understanding the closures needed to complete this model and we show the vital need to understand the pressure head losses over the jump, which we show can be related to the vorticity fluxes at the boundaries of the control volume. Our formulation leads to two governing equations for three dimensionless quantities. Closure requires one further assumption, depending on which we demonstrate that previous models for gravity current fronts and internal bores can be recovered. This analysis yield new insights into existing results, and also provides constraints for potential new formulae.

  9. MRI-conditional pacemakers: current perspectives

    Directory of Open Access Journals (Sweden)

    Ferreira AM

    2014-05-01

    Full Text Available António M Ferreira,1,2 Francisco Costa,2 António Tralhão,2 Hugo Marques,3 Nuno Cardim,1 Pedro Adragão1,2 1Cardiology Department, Hospital da Luz, 2Cardiology Department, Hospital Santa Cruz- CHLO, 3Radiology Department, Hospital da Luz, Lisbon, Portugal Abstract: Use of both magnetic resonance imaging (MRI and pacing devices has undergone remarkable growth in recent years, and it is estimated that the majority of patients with pacemakers will need an MRI during their lifetime. These investigations will generally be denied due to the potentially dangerous interactions between cardiac devices and the magnetic fields and radiofrequency energy used in MRI. Despite the increasing reports of uneventful scanning in selected patients with conventional pacemakers under close surveillance, MRI is still contraindicated in those circumstances and cannot be considered a routine procedure. These limitations prompted a series of modifications in generator and lead engineering, designed to minimize interactions that could compromise device function and patient safety. The resulting MRI-conditional pacemakers were first introduced in 2008 and the clinical experience gathered so far supports their safety in the MRI environment if certain conditions are fulfilled. With this technology, new questions and controversies arise regarding patient selection, clinical impact, and cost-effectiveness. In this review, we discuss the potential risks of MRI in patients with electronic cardiac devices and present updated information regarding the features of MRI-conditional pacemakers and the clinical experience with currently available models. Finally, we provide some guidance on how to scan patients who have these devices and discuss future directions in the field. Keywords: pacemakers, magnetic resonance imaging, MRI, MRI-conditional devices, safety

  10. Remote ischemic conditioning: Current clinical perspectives.

    Science.gov (United States)

    Le Page, Sophie; Prunier, Fabrice

    2015-08-01

    Remote ischemic conditioning (RIC) constitutes a promising method in which a tissue or organ is exposed to intermittent ischemia/reperfusion periods enabling it to provide protection to a distant target organ. RIC has been tested in various clinical settings through its simple application by means of intermittent inflation of a blood pressure cuff placed on a limb, primarily evaluating its potential abilities to decrease myocardial injury biomarkers. Its use on other organs, such as the kidneys or brain, has recently been a topic of research. To date, no study has yet been powerful enough to reach a conclusion on the potential benefit of RIC on clinical outcomes. The future role of RIC in the clinical arena could be clarified by the large phase III trials currently underway targeting major outcomes as primary endpoints.

  11. Current leakage performance of dielectric elastomers under different boundary conditions

    Science.gov (United States)

    Lu, Tongqing; Shi, Zhibao; Chen, Zhiqiang; Huang, He; Wang, T. J.

    2015-10-01

    In the past decade, dielectric elastomers have become promising candidates in the applications of soft electromechanical transducers due to their outstanding properties of large deformation and high energy density. Current leakage of dielectric elastomer is one of the important dissipative mechanisms affecting the energy conversion efficiency. In this work, we experimentally investigate the current leakage performance of dielectric elastomers with different boundary conditions. We find that for displacement-type boundary conditions, the transition from Ohmic conduction to non-Ohmic conduction is abrupt near the critical electric field. By comparison, for force-type boundary conditions, the current leakage density versus electric field curve is smooth and is fit well by an exponential function. The equivalent resistivity of dielectric elastomers under force-type boundary conditions is approximately an order of magnitude smaller than that under displacement-type boundary conditions. The difference is qualitatively explained by a microscopic physical model. These results will help to design and optimize dielectric elastomer transducers to improve their energy conversion efficiency.

  12. Modeling of Current Transformers Under Saturation Conditions

    Directory of Open Access Journals (Sweden)

    Martin Prochazka

    2006-01-01

    Full Text Available During a short circuit the input signal of the relay can be distort by the magnetic core saturation of the current transformer. It is useful to verify the behavior of CT by a mathematical model. The paper describes one phase and three phase models and it presents some methods of how to analyze and classify a deformed secondary current

  13. Development for Thermophoresis Experimental Under Microgravity Condition

    Science.gov (United States)

    Suardi, Mirnah Binti; Razali, Mohd Azahari bin; Khalid, Amir bin; Salleh, Hamidon bin; Sapit, Azwan; Mohammed, Akmal Nizam bin; Hushim, Mohd Faisal bin

    2016-11-01

    In the temperature field, a small particle will move towards the lower temperature side. This phenomenon is called thermophoresis, which influences the movement of soot particles in exhaust gas from combustors. It is important to understand the behavior of soot particles in the combustion field for emission control. The main problem for measuring the thermophoretic velocity is the natural convection. The velocity of such natural convection is usually comparable to the thermophoretic velocity and cannot be measured directly. To avoid this problem, experiments should be conducted under microgravity conditions. . In the present work, device has been developed for conducting experiments repeatedly under a microgravity environment in a very short period time, i.e. 0.3 s, by means of the free-fall method, to accumulate data of the thermophoretic velocity. Experiments have been conducted to measure the movement of particles in the microgravity environment with and without temperature gradient. For the former experiment, it is seen that the particles has almost no movement in the horizontal and the vertical directions. Results confirmed that there is negligible effect of blowing and gravitational on the particles movement. For the later one, experiments have been done in a surrounding of a pure gas of argon. The thermophoretic velocity is measured at 313±2 K for various pressure conditions from 20 kPa to 100 kPa. The thermophoretic velocity for each particle is individually measured, and the mean value and its 95% confidence interval for each experimental condition are statistically obtained. Result from experiments are compared with the theory and satisfactorily agreement is found for tested gas.

  14. Condition for the occurrence of phase slip centers in superconducting nanowires under applied current or voltage

    DEFF Research Database (Denmark)

    Michotte, S.; Mátéfi-Tempfli, Stefan; Piraux, L.;

    2004-01-01

    Experimental results on the phase slip process in superconducting lead nanowires are presented under two different experimental conditions: constant applied current or constant voltage. Based on these experiments we established a simple model which gives us the condition of the appearance of phas...

  15. Metabolic Desynchronization in Critical Conditions: Experimental Study

    Directory of Open Access Journals (Sweden)

    G. V. Livanov

    2006-01-01

    Full Text Available Objective. To conduct an experimental study of the impact of the time of administration of succinic acid preparations on central nervous system (CNS function and gas exchange while simulating metabolic therapy for severe poisoning by ethyl alcohol. The study was performed on 74 male albino rats weighing 140—180 g. Acute severe and very severe intoxication was simulated, by intraabdominally administering 30% ethanol to the rats. Cytoflavin was used to simulate experimental therapy. The rate of gas exchange was estimated by the oxygen uptake determined by the closed chamber method in a Regnault apparatus (Germany. Spontaneous bioelectrical activity was recorded in the frontooccipital lead by the routine procedure. External pain stimulation and rhythmical photostimulation were employed to evaluate cerebral responsiveness. Heterodirectional EEG changes in the «early» and «late» administration of succinate were not followed by the similar alterations of gas exchange: oxygen consumption in both the «early» and «late» administration of succinate remained significantly lower than in the control animals. With the late administration of succinate to the animals with mixed (toxic and hypoxic coma, the so-called discrepancy between the noticeably increased energy production and brutally diminished metabolism occurred. It may be just the pathological mechanism that was the basis for higher mortality in the late succinate administration group. The findings and their analysis make it possible to advance a hypothesis that succinate may cause metabolic desynchronization if activation of metabolic processes takes place under severe tissue respiratory tissue depression. In these cases, there is a severe damage to tissue and chiefly the brain. This manifests itself as EEG epileptiform activity splashes preceding the animals’ death. Therefore, resuscitation aimed at restoring the transport of oxygen and its involvement in tissue energy processes should

  16. Experimental observation of direct current voltage-induced phase synchronization

    Indian Academy of Sciences (India)

    Haihong Li; Weiqing Liu; Qiongling Dai; Jinghua Xiao

    2006-09-01

    The dynamics of two uncoupled distinct Chua circuits driven by a common direct current voltage is explored experimentally. It was found that, with increasing current intensity, the dominant frequencies of these two Chua circuits will first vary at different speeds, approach an identical value for a certain current intensity and then separate. Techniques such as synchronization index and phase difference distribution were employed to analyze the phase coherence between these two Chua circuits.

  17. Experimental Setup for the Investigation of Superconducting Persistent Current

    Science.gov (United States)

    2015-09-01

    NOTES 14. ABSTRACT We report on a recent experimental setup for the investigation of the relaxation rate of the persistent current in an assembly of...at cryo-temperatures in magnetic field at time scale of seconds to hours. 15. SUBJECT TERMS persistent current, 2G HTS, coated conductor, relaxation ... activation . One unknown aspect is the variation of the coils’ position with temperature from room to cryogenic. A better design of the coils assembly

  18. Study on Fault Current of DFIG during Slight Fault Condition

    OpenAIRE

    Xiangping Kong; Zhe Zhang; Xianggen Yin; Zhenxing Li

    2013-01-01

    In order to ensure the safety of DFIG when severe fault happens, crowbar protection is adopted. But during slight fault condition, the crowbar protection will not trip, and the DFIG is still excited by AC-DC-AC converter. In this condition, operation characteristics of the converter have large influence on the fault current characteristics of DFIG. By theoretical analysis and digital simulation, the fault current characteristics of DFIG during slight voltage dips are studied. And the influenc...

  19. The theoretical analysis and experimental research on the optimal condition of semiconductor refrigeration

    Science.gov (United States)

    Pang, Y. F.

    2016-08-01

    The traditional limiting conditions have the biggest refrigeration quantity condition and the biggest refrigeration coefficient condition, there is a special operating mode during these conditions, enabling to both have the big refrigeration quantity and the small power loss, this operating mode is “Optimum condition”. This article first carried on the theoretical analysis to the semiconductor's optimum condition, inferred optimum electric current's theoretical formula; Carried on the experiment again to a semiconductor refrigeration box by regulating current changing operating mode, which had analyzed performance parameter's change situation under 8 kinds of condition experiments, carried on the regression analysis to the experimental data, obtained the regression equation thus discovered optimum electric current corresponding optimum condition. Carried on working under this condition, and then obtained the big refrigeration quantity and small power, which enhanced the refrigeration performance of semiconductor refrigerator. The experimental result and the theoretical analysis result tallied basically.

  20. Experimental typography : reviewing the modernist and the current approaches

    OpenAIRE

    Makal, Eray

    1993-01-01

    Ankara : The Department of Graphic Design and Institute of Fine Arts, Bilkent Univ., 1993. Thesis (Master's) -- Bilkent University, 1993. Includes bibliographical references leaves 65-66. The intention of this study is to evaluate the experimental typography within the history of graphic design by taking in consideration of two epochs. The Modernist and The Current. Makal, Eray M.S.

  1. Halo current diagnostic system of experimental advanced superconducting tokamak

    Energy Technology Data Exchange (ETDEWEB)

    Chen, D. L.; Shen, B.; Sun, Y.; Qian, J. P., E-mail: jpqian@ipp.ac.cn; Wang, Y.; Xiao, B. J. [Institute of Plasma Physics, Chinese Academy of Sciences, P.O. Box 1126, Hefei 230031 (China); Granetz, R. S. [MIT Plasma Science and Fusion Center, Cambridge, Massachusetts 02139 (United States)

    2015-10-15

    The design, calibration, and installation of disruption halo current sensors for the Experimental Advanced Superconducting Tokamak are described in this article. All the sensors are Rogowski coils that surround conducting structures, and all the signals are analog integrated. Coils with two different cross-section sizes have been fabricated, and their mutual inductances are calibrated. Sensors have been installed to measure halo currents in several different parts of both the upper divertor (tungsten) and lower divertor (graphite) at several toroidal locations. Initial measurements from disruptions show that the halo current diagnostics are working well.

  2. Halo current diagnostic system of experimental advanced superconducting tokamak

    Science.gov (United States)

    Chen, D. L.; Shen, B.; Granetz, R. S.; Sun, Y.; Qian, J. P.; Wang, Y.; Xiao, B. J.

    2015-10-01

    The design, calibration, and installation of disruption halo current sensors for the Experimental Advanced Superconducting Tokamak are described in this article. All the sensors are Rogowski coils that surround conducting structures, and all the signals are analog integrated. Coils with two different cross-section sizes have been fabricated, and their mutual inductances are calibrated. Sensors have been installed to measure halo currents in several different parts of both the upper divertor (tungsten) and lower divertor (graphite) at several toroidal locations. Initial measurements from disruptions show that the halo current diagnostics are working well.

  3. Experimental Conditions - Metabolonote | LSDB Archive [Life Science Database Archive metadata

    Lifescience Database Archive (English)

    Full Text Available 908/lsdba.nbdc01324-009 Description of data contents It is the list of sample (S) with Analytical Method (M)...[ Credits ] English ]; } else if ( url.search(//en//) != -1 ) { url = url.replace(/... English ]; } else { document.getElementById(lang).innerHTML= '[ Japanese | English ]'; } } window.onload = swit...List Contact us Metabolonote Experimental Conditions Data detail Data name Experimental Conditions DOI 10.18... and Data Analysis (D) etc. Data file File name: metabolonote_experimental_conditions.zip File URL: ftp://ft

  4. Balanced Current Control Strategy for Current Source Rectifier Stage of Indirect Matrix Converter under Unbalanced Grid Voltage Conditions

    Directory of Open Access Journals (Sweden)

    Yeongsu Bak

    2016-12-01

    Full Text Available This paper proposes a balanced current control strategy for the current source rectifier (CSR stage of an indirect matrix converter (IMC under unbalanced grid voltage conditions. If the three-phase grid connected to the voltage source inverter (VSI of the IMC has unbalanced voltage conditions, it affects the currents of the CSR stage and VSI stage, and the currents are distorted. Above all, the distorted currents of the CSR stage cause instability in the overall system, which can affect the life span of the system. Therefore, in this paper, a control strategy for balanced currents in the CSR stage is proposed. To achieve balanced currents in the CSR stage, the VSI stage should receive DC power without ripple components from the CSR stage. This is implemented by controlling the currents in the VSI stage. Therefore, the proposed control strategy decouples the positive and negative phase-sequence components existing in the unbalanced voltages and currents of the VSI stage. Using the proposed control strategy under unbalanced grid voltage conditions, the stability and life span of the overall system can be improved. The effectiveness of the proposed control strategy is verified by simulation and experimental results.

  5. Experimental Gravity Currents Propagating Downslope Over A Synthetic Topography

    Science.gov (United States)

    Burgos Cuevas, Andrea; Ruiz-Angulo, Angel; Palacios-Morales, Carlos

    2016-11-01

    Lock-release gravity currents are studied experimentally in order to investigate their dynamics and the mixing process between them and the ambient fluid. We produced these currents in a laboratory tank and allow them to propagate downslope first in a flat slope and then in a rough one with a synthetic topography. This topography is similar to the one of a side of a mountain near mexico's valley. Our aim is to investigate the dynamics of gravity currents as similar as possible to the mountain breezes that can develop around this valley. To the best of our knowledge, there are few experimental investigations that take into account the roughness of the slope. For each experiment, we obtain the instantaneous velocity fields using the standard piv technique. From the velocity fields, we estimate the entrainment coefficient time series. We found that this coefficient depends on the roughness of the surface where the current propagates. Besides, pressure time series were obtained in synthetic stations along the rough profile. These series showed a very clear signal of the gravity current propagating along the slope.

  6. Durability Study of SOFCs Under Cycling Current Load Conditions

    DEFF Research Database (Denmark)

    Hagen, Anke; Hendriksen, Peter Vang; Frandsen, Henrik Lund;

    2009-01-01

    In fuel cell applications, the cells must be able to withstand varying operating conditions. Anode supported solid oxide fuel cells were tested under cycling current load in order to determine the durability and possibly identify degradation mechanisms. At 750 °C and a cycling between zero and 0.......75 A cm-2, the cell voltage degradation rate was similar to tests with the corresponding high constant current density. However, by analyzing the impedance spectra it was found that anode degradation was becoming more important when going from constant to cycling conditions. Running the cycling load tests...... at 850 °C, the cells degraded similarly as under the corresponding constant current load whereas, in some cases, cells failed mechanically after a few hundred hours. These cells did not experience severe additional degradation due to the cycling of the current density until the point of failure...

  7. As it happens: current directions in experimental evolution.

    Science.gov (United States)

    Bataillon, Thomas; Joyce, Paul; Sniegowski, Paul

    2013-02-23

    Recent decades have seen a significant rise in studies in which evolution is observed and analysed directly-as it happens-under replicated, controlled conditions. Such 'experimental evolution' approaches offer a degree of resolution of evolutionary processes and their underlying genetics that is difficult or even impossible to achieve in more traditional comparative and retrospective analyses. In principle, experimental populations can be monitored for phenotypic and genetic changes with any desired level of replication and measurement precision, facilitating progress on fundamental and previously unresolved questions in evolutionary biology. Here, we summarize 10 invited papers in which experimental evolution is making significant progress on a variety of fundamental questions. We conclude by briefly considering future directions in this very active field of research, emphasizing the importance of quantitative tests of theories and the emerging role of genome-wide re-sequencing.

  8. Experimental observation of dynamic ductile damage development under various triaxiality conditions - description of the principle

    Science.gov (United States)

    Pillon, L.

    2012-08-01

    The Gurson model has been extended by Perrin to describe damage evolution in ductile viscoplastic materials. The so-called Gurson-Perrin model allows representing damage development with respect to strain-rate conditions. In order to fill a lack in current experimental procedures, we propose an experimental project able to test and validate the Gurson-Perrin model under various dynamic conditions and for different stress triaxiality levels.

  9. Experimental observation of dynamic ductile damage development under various triaxiality conditions - description of the principle

    Directory of Open Access Journals (Sweden)

    Pillon L.

    2012-08-01

    Full Text Available The Gurson model has been extended by Perrin to describe damage evolution in ductile viscoplastic materials. The so-called Gurson-Perrin model allows representing damage development with respect to strain-rate conditions. In order to fill a lack in current experimental procedures, we propose an experimental project able to test and validate the Gurson-Perrin model under various dynamic conditions and for different stress triaxiality levels.

  10. Experimental simulation of gravity currents in erodible bed

    Science.gov (United States)

    Bateman, A.; La Roca, M.; Medina, V.

    2009-04-01

    Gravity currents are commonly met in nature, when a flow of denser fluid moves into a less dense one. A typical example of a gravity current is given by the sea water which flows into the bottom of a river during the summer, in correspondence of the estuary, when the river's discharge attains low values. In this case, dangerous consequences can occur, because of the polluting of the aquifer caused by the salty water. Density currents also occurs in lakes and reservoirs, because of a change in temperature or because a flood, both can produce some environmental impacts that are of interest to the local water Agency of the different countries. Of particular relevance is also the interaction of the gravity current with the movement of the sediments from the bottom of the bed. The international state of the art is particularly concerned with experimental and numerical investigation on gravity currents on fixed and porous bed [1-2-3], while, to the authors' knowledge, the interaction of a gravity current with an erodible bed is still an open field of investigation. In this paper experiments concerning with the propagation of a gravity current over fixed and erodible bed are presented. The experiments, conducted at the laboratory of Hydraulics of the Universitat Politecnica de Catalunya (actually in the Prof. Bateman's blue room), were concerned with a transparent tank 2 m long, 0.2 m wide and 0.3 m deep, partly filled with salty water and partly with fresh water, up to a depth of 0.28 m. The salty water, whose density was in the range 1050John E. Simpson. Gravity Currents [3] J.J. Monaghan, R.A.F. Cas, A.M. Kos, M. Hallworth, Gravity currents descending a ramp in a stratified tank, The Journal of Fluid Mechanics, Vol. 379, 1999

  11. Zinc electrowinning: anode conditioning and current distribution studies

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, J.A. [Cominco Research, Cominco Ltd., Trail, British Columbia (Canada)

    2001-07-01

    In the zinc electrowinning (EW) process, Pb-Ag anodes are widely used. Prior to their use in the EW process, anodes are conditioned to form a stable oxide layer that can evolve O{sub 2} without excessive Pb contamination of the cathode and MnO{sub 2} precipitation. The most widely used conditioning techniques are: passivation in a KF-H{sub 2}SO{sub 4} electrolysis bath, chemical oxidation in a KMnO{sub 4}-H{sub 2}SO{sub 4} solution, and sandblasting. In this paper, a comparison of these treatments using flat and corrugated anodes is presented. Laboratory and industrial-scale tests carried out at Cominco's Trail and Cajamarquilla zinc plants indicated that flat anodes should be sandblasted or electrochemically passivated before their use in the Zn electrowinning process. Further, corrugated anodes should be sandblasted or chemically conditioned in a KMnO{sub 4}-H{sub 2}SO{sub 4} -electrolyte. The beneficial effects of chemical conditioning are lost if the anode is non-corrugated. Flat, chemically conditioned anodes generate up to 10 times more mud than corrugated-chemically conditioned anodes. Because anode mud growth is evenly distributed on sandblasted anodes, short-circuit frequency may decrease and anode life may increase. Sandblasting does not appear to affect anode performance. Parallel to the industrial anode conditioning tests, current distribution measurements were made. Current flow measurements were used to correct troublesome electrodes and/or bad electrical contacts. In Cajamarquilla, this technique was used in four industrial electrowinning cells and energy consumption values lower than 3000 kWh/t Zn were obtained at current efficiencies as high as 95% and at current densities up to 450 A/m{sup 2}. (author)

  12. SHADOW PROCESSES INSTATE BUDGET: CURRENT CONDITION AND DETERMINING FACTORS

    Directory of Open Access Journals (Sweden)

    Z. Varnalii

    2014-12-01

    Full Text Available The most significant factors that move state budget into the shadow are determined. Current condition of shadow processes in state budget is highlighted. The paper also provides an analysis of relationship between political processes and shadow economy in public sector of Ukraine.

  13. Fault Current Characteristics of the DFIG under Asymmetrical Fault Conditions

    Directory of Open Access Journals (Sweden)

    Fan Xiao

    2015-09-01

    Full Text Available During non-severe fault conditions, crowbar protection is not activated and the rotor windings of a doubly-fed induction generator (DFIG are excited by the AC/DC/AC converter. Meanwhile, under asymmetrical fault conditions, the electrical variables oscillate at twice the grid frequency in synchronous dq frame. In the engineering practice, notch filters are usually used to extract the positive and negative sequence components. In these cases, the dynamic response of a rotor-side converter (RSC and the notch filters have a large influence on the fault current characteristics of the DFIG. In this paper, the influence of the notch filters on the proportional integral (PI parameters is discussed and the simplified calculation models of the rotor current are established. Then, the dynamic performance of the stator flux linkage under asymmetrical fault conditions is also analyzed. Based on this, the fault characteristics of the stator current under asymmetrical fault conditions are studied and the corresponding analytical expressions of the stator fault current are obtained. Finally, digital simulation results validate the analytical results. The research results are helpful to meet the requirements of a practical short-circuit calculation and the construction of a relaying protection system for the power grid with penetration of DFIGs.

  14. Experimental study of the dynamics of a thin current sheet

    Science.gov (United States)

    Gekelman, W.; DeHaas, T.; Van Compernolle, B.; Daughton, W.; Pribyl, P.; Vincena, S.; Hong, D.

    2016-05-01

    Many plasmas in natural settings or in laboratory experiments carry currents. In magnetized plasmas the currents can be narrow field-aligned filaments as small as the electron inertial length ≤ft(\\tfrac{c}{{ω }pe}\\right) in the transverse dimension or fill the entire plasma column. Currents can take the form of sheets, again with the transverse dimension the narrow one. Are laminar sheets of electric current in a magnetized plasma stable? This became an important issue in the 1960s when current-carrying plasmas became key in the quest for thermonuclear fusion. The subject is still under study today. The conditions necessary for the onset for tearing are known, the key issue is that of the final state. Is there a final state? One possibility is a collection of stable tubes of current. On the other hand, is the interaction between the current filaments which are the byproduct endless, or does it go on to become chaotic? The subject of three-dimensional current systems is intriguing, rich in a variety of phenomena on multiple scale sizes and frequencies, and relevant to fusion studies, solar physics, space plasmas and astrophysical phenomena. In this study a long (δz = 11 m) and narrow (δx = 1 cm, δy = 20 cm) current sheet is generated in a background magnetoplasma capable of supporting Alfvén waves. The current is observed to rapidly tear into a series of magnetic islands when viewed in a cross-sectional plane, but they are in essence three-dimensional flux ropes. At the onset of the current, magnetic field line reconnection is observed between the flux ropes. The sheet on the whole is kink-unstable, and after kinking exhibits large-scale, low-frequency (f ≪ f ci ) rotation about the background field with an amplitude that grows with distance from the source of the current. Three-dimensional data of the magnetic and electric fields is acquired throughout the duration of the experiment and the parallel resistivity is derived from it. The parallel

  15. Study on Fault Current of DFIG during Slight Fault Condition

    Directory of Open Access Journals (Sweden)

    Xiangping Kong

    2013-04-01

    Full Text Available In order to ensure the safety of DFIG when severe fault happens, crowbar protection is adopted. But during slight fault condition, the crowbar protection will not trip, and the DFIG is still excited by AC-DC-AC converter. In this condition, operation characteristics of the converter have large influence on the fault current characteristics of DFIG. By theoretical analysis and digital simulation, the fault current characteristics of DFIG during slight voltage dips are studied. And the influence of controller parameters of converter on the fault current characteristics is analyzed emphatically. It builds a basis for the construction of relay protection which is suitable for the power gird with accession of DFIG.

  16. SUSY effects in Rb: Revisited under current experimental constraints

    Science.gov (United States)

    Su, Wei; Yang, Jin Min

    2016-06-01

    In this note we revisit the SUSY effects in Rb under current experimental constraints including the LHC Higgs data, the B-physics measurements, the dark matter relic density and direct detection limits, as well as the precision electroweak data. We first perform a scan to figure out the currently allowed parameter space and then display the SUSY effects in Rb. We find that although the SUSY parameter space has been severely restrained by current experimental data, both the general MSSM and the natural-SUSY scenario can still alter Rb with a magnitude sizable enough to be observed at future Z-factories (ILC, CEPC, FCC-ee, Super Z-factory) which produce 109-1012Z-bosons. To be specific, assuming a precise measurement δRb = 2.0 ×10-5 at FCC-ee, we can probe a right-handed stop up to 530 GeV through chargino-stop loops, probe a sbottom to 850 GeV through neutralino-sbottom loops and a charged Higgs to 770 GeV through the Higgs-top quark loops for a large tan ⁡ β. The full one-loop SUSY correction to Rb can reach 1 ×10-4 in natural SUSY and 2 ×10-4 in the general MSSM.

  17. Conditional vs. Voluntary Contribution Mechanism – An Experimental Study

    OpenAIRE

    Reischmann, Andreas

    2015-01-01

    The Conditional Contribution Mechanism for public good provision gives all agents the possibility to condition their contribution on the total level of contribution provided by all agents. In this experimental study the mechanism's performance is compared to the performance of the Voluntary Contribution Mechanism. In an environment with binary contribution and linear valuations subjects play the mechanisms in a repeated setting. The mechanisms are compared in one case of complete informati...

  18. Multi-frequency proportional-resonant (MFPR) current controller for PWM VSC under unbalanced supply conditions

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    This letter presents a multi-frequency proportional-resonant (MFPR) current controller developed for PWM voltage source converter (VSC) under the unbalanced supply voltage conditions. The delta operator is used in place of the shift operator for the implementation of MFPR by using a low-cost fixed-point DSP. The experimental results with an alternative control strategy validated the feasibility of the proposed MFPR current controller for the PWM VSC during voltage unbalance.

  19. Water-waves on linear shear currents. A comparison of experimental and numerical results.

    Science.gov (United States)

    Simon, Bruno; Seez, William; Touboul, Julien; Rey, Vincent; Abid, Malek; Kharif, Christian

    2016-04-01

    Propagation of water waves can be described for uniformly sheared current conditions. Indeed, some mathematical simplifications remain applicable in the study of waves whether there is no current or a linearly sheared current. However, the widespread use of mathematical wave theories including shear has rarely been backed by experimental studies of such flows. New experimental and numerical methods were both recently developed to study wave current interactions for constant vorticity. On one hand, the numerical code can simulate, in two dimensions, arbitrary non-linear waves. On the other hand, the experimental methods can be used to generate waves with various shear conditions. Taking advantage of the simplicity of the experimental protocol and versatility of the numerical code, comparisons between experimental and numerical data are discussed and compared with linear theory for validation of the methods. ACKNOWLEDGEMENTS The DGA (Direction Générale de l'Armement, France) is acknowledged for its financial support through the ANR grant N° ANR-13-ASTR-0007.

  20. Strength and conditioning in tennis: current research and practice.

    Science.gov (United States)

    Reid, Machar; Schneiker, Knut

    2008-06-01

    Virtually all professional tennis players are in continuous pursuit of enhanced performance. With the modern game becoming increasingly dynamic and tournament schedules no less demanding, the importance of physical fitness is well accepted. Indeed, most professional tennis players resource strength and conditioning specialists on a full- or part-time basis. As tennis play is characterised by intricate bio-energetics, planning specific strength and conditioning interventions represents a significant challenge for the specialist. Further, where game physiology and mechanics have been described extensively, critiques of the efficacy of different training initiatives are far less common. This review therefore considers the current scientific, tennis-specific fitness training evidence base in light of contemporary conditioning, and more particularly resistance training, practices.

  1. The mycotoxin distribution in maize milling fractions under experimental conditions.

    Science.gov (United States)

    Burger, H-M; Shephard, G S; Louw, W; Rheeder, J P; Gelderblom, W C A

    2013-07-01

    Mycotoxin contamination of maize and maize-based food and feed products poses a health risk to humans and animals if not adequately controlled and managed. The current study investigates the effect of dry milling on the reduction of fumonisins (FB), deoxynivalenol (DON) and zearalenone (ZEA) in maize. Five composite samples, constructed to represent different mycotoxin contamination levels were degermed yielding degermed maize and the germ. The degermed maize was milled under laboratory conditions and four major milling fractions (SPECIAL, SUPER, semolina (SEM) and milling hominy feed) collected. The whole maize, degermed maize and total hominy feed (germ+milling hominy feed) were reconstructed to ensure homogenous samples for mycotoxin analyses. For comparison, commercial dry milling fractions (whole maize, SPECIAL, SUPER and total hominy feed), collected from three South African industrial mills, were analysed for the same mycotoxins and hence a more accurate assessment of the distribution between the different milling fractions. The distribution of the mycotoxins during the experimental dry milling of the degermed maize differs, with FB mainly concentrated in the SPECIAL, DON in the SEM whereas ZEA was equally distributed between the two milling fractions. Distribution of mycotoxins between the fractions obtained during commercial dry milling generally provided similar results with the total hominy feed containing the highest and the SUPER milling fractions the lowest mycotoxin levels although variations existed. Although milling is an effective way to reduce mycotoxins in maize, kernel characteristics and resultant fungal colonisation may impact on the distribution of specific mycotoxins among the different milling fractions. Differences in industrial dry milling practices and problems encountered in sampling bulk maize remain a large problem in assessing mycotoxin contamination in milling fractions intended for human consumption.

  2. Experimental Investigation of Turbulence Specifications of Turbidity Currents

    Directory of Open Access Journals (Sweden)

    B Firoozabadi

    2010-01-01

    Full Text Available The present study investigates the turbulence characteristic of turbidity current experimentally. The three-dimensional Acoustic-Doppler Velocimeter (ADV was used to measure the instantaneous velocity and characteristics of the turbulent flow. The experiments were conducted in a three-dimensional channel for different discharge flows, concentrations, and bed slopes. Results are expressed at various distances from the inlet, for all flow rates, slopes and concentrations as the distribution of turbulence energy, Reynolds stress and the turbulent intensity. It was concluded that the maximum turbulence intensity happens in both the interface and near the wall. Also, it was observed that the turbulence intensity reaches its minimum where maximum velocity occurs.

  3. Recent experimental results of KSTAR RF heating and current drive

    Energy Technology Data Exchange (ETDEWEB)

    Wang, S. J., E-mail: sjwang@nfri.re.kr; Kim, J.; Jeong, J. H.; Kim, H. J.; Joung, M.; Bae, Y. S.; Kwak, J. G. [National Fusion Research Institute, Daejoen, 305-806 (Korea, Republic of)

    2015-12-10

    The overview of KSTAR activities on ICRH, LHCD and ECH/CD including the last experimental results and future plan aiming for long-pulse high-beta plasma will be presented. Recently we achieved reasonable coupling of ICRF power to H-mode plasma through several efforts to increase system reliability. Power balance will be discussed on this experiment. LHCD is still struggling in the low power regime. Review of antenna spectrum for the higher coupling in H-mode plasma will be tried. ECH/CD provides 41 sec, 0.8 MW of heating power to support high-performance long-pulse discharge. Also, 170 GHz ECH system is integrated with the Plasma Control System (PCS) for the feedback controlling of NTM. Status and plan of ECH/CD will be discussed. Finally, helicon current drive is being prepared for the next stage of KSTAR operation. The hardware preparation and the calculation results of helicon current drive in KSTAR plasma will be discussed.

  4. Micromorphology of neurohypophysis of rats under experimental conditions

    Science.gov (United States)

    Meitner, E. R.; Proksova, E.

    1979-01-01

    The changes of the quantity of neurosecretory substance in neurohypophysis of rats under various experimental conditions are investigated. Comparing to the norm the quantity of neurosecretion after a long stay in the dark was larger. In animals subjected to immobilization stress the picture of neurohypophysis remained unchanged. It changed only in correlation with the administered water. Results indicate that the immobilization stress, in contradistinction to dolorose stress, has no substantial influence upon the quantity of neurosecretion in neurohypophysis.

  5. Wake Survey of a Marine Current Turbine Under Steady Conditions

    Science.gov (United States)

    Lust, Ethan; Luznik, Luksa; Flack, Karen

    2016-11-01

    A submersible particle image velocimetry (PIV) system was used to study the wake of a horizontal axis marine current turbine. The turbine was tested in a large tow tank facility at the United States Naval Academy. The turbine is a 1/25th scale model of the U.S. National Renewable Energy Laboratory's Reference Model 1 (RM1) tidal turbine. It is a two-bladed turbine measuring 0.8 m in diameter and featuring a NACA 63-618 airfoil cross section. Separate wind tunnel testing has shown the foil section used on the turbine to be Reynolds number independent with respect to lift at the experimental parameters of tow carriage speed (Utow = 1 . 68 m/s) and tip speed ratio (TSR = 7). The wake survey was conducted over an area extending 0.25D forward of the turbine tip path to 2.0D aft, and to a depth of 1.0D beneath the turbine output shaft in the streamwise plane. Each field of view was approximately 30 cm by 30 cm, and each overlapped the adjacent fields of view by 5 cm. The entire flow field was then reconstructed into a single field of investigation. Results include streamwise and vertical ensemble average velocity fields averaged over approximately 1,000 realizations, as well as higher-order statistics. Turbine tip vortex centers were identified and plotted showing increasing aperiodicity with wake age. keywords: horizontal axis marine current turbine, particle image velocimetry, towing tank, wake survey

  6. Conditions for Lower Hybrid Current Drive in ITER

    Science.gov (United States)

    Cesario, R.; Amicucci, L.; Cardinali, A.; Castaldo, C.; Ceccuzzi, S.; Napoli, F.; Tuccillo, A. A.; Galli, A.; Schettini, G.

    2012-12-01

    To control the plasma current profile represents one of the most important problems of the research of nuclear fusion energy based on the tokamak concept, as in the plasma column the necessary conditions of stability and confinement should be satisfied. This problem can be solved by using the lower hybrid current drive (LHCD) effect, which was demonstrated to occur also at reactor grade high plasma densities provided that a proper method should be utilised, as assessed on FTU (Frascati Tokamak Upgrade). This method, based on theoretical predictions confirmed by experiment, produces relatively high electron temperature at the plasma periphery and scrape-off layer (SOL), consequently reducing the broadening of the spectrum launched by the antenna produced by parasitic wave physics of the edge, namely parametric instability (PI). The new results presented here show that, for kinetic profiles now foreseen for the SOL of ITER, PI is expected to hugely broaden the antenna spectrum and prevent any penetration in the core of the coupled LH power. However, considering the FTU method and assuming higher electron temperature at the edge (which would be however reasonable for ITER) the PI-produced spectral broadening would be mitigated, and enable the penetration of the coupled LH power in the main plasma. By successful LHCD effect, the control of the plasma current profile at normalised minor radius of about 0.8 would be possible, with much higher efficiency than that obtainable by other tools. A very useful reinforce of bootstrap current effects would be thus possible by LHCD in ITER.

  7. ITER (International Thermonuclear Experimental Reactor) current drive and heating physics

    Energy Technology Data Exchange (ETDEWEB)

    Nevins, W.M.; Lindquist, W. (Lawrence Livermore National Lab., CA (USA)); Fujisawa, N.; Kimura, H. (Japan Atomic Energy Research Inst., Naka, Ibaraki (Japan)); Hopman, H.; Rebuffi, L.; Wegrowe, J.G. (Max-Planck-Institut fuer Plasmaphysik, Garching (Germany, F.R.). NET Design Team); Parail, V.; Vdovin, V. (Gosudarstvennyj Komitet po Ispol' zovaniyu Atomnoj Ehnergii SSSR, Moscow (USSR). Inst. Atomnoj Ehn

    1990-01-01

    The ITER Current Drive and Heating (CD H) systems are required for: Ionization and current initiation; Non-inductive current ramp-up assist; Heating of the plasma; Steady-state operation with full non-inductive current drive; Current profile control; and Burn control by modulation of the auxiliary power. Steady-state current drive is the most demanding requirement, so this has driven the choice of the ITER current drive and heating systems.

  8. Machine Induced Experimental Background Conditions in the LHC

    CERN Document Server

    Levinsen, Yngve Inntjore; Stapnes, Steinar

    2012-09-19

    The Large Hadron Collider set a new energy record for particle accelerators in late 2009, breaking the previous record held by Tevatron of 2 TeV collision energy. The LHC today operates at a collision energy of 7 TeV. With higher beam energy and intensity, measures have to be taken to ensure optimal experimental conditions and safety of the machine and detectors. Machine induced experimental background can severely reduce the quality of experimental triggers and track reconstruction. In a worst case, the radiation levels can be damaging for some of the subdetectors. The LHC is a particular challenge in this regard due to the vastly different operating conditions of the different experiments. The nominal luminosity varies by four orders of magnitude. The unprecedented stored beam energy and the amount of superconducting elements can make it challenging to protect the accelerator itself as well. In this work we have simulated and measured the machine induced background originating from various sources: the beam...

  9. Experimental Research on Liquid Desiccant Air-conditioning Unit

    Directory of Open Access Journals (Sweden)

    Feng Yueyan

    2016-01-01

    Full Text Available An experimental device of liquid desiccant air conditioning system is established. Experimental tests about the temperature difference between diluted solution of inlet and concentrated solution of exit in the solution heat exchanger are carried on, and CaCl2 solution is used as desiccant. Results show that: the fluctuation range in the day at different times of the basic difference of the measured temperature does not exceed 1°C, and the temperature difference between diluted solution of inlet and concentrated solution of exit in solution heat exchanger appears the minimum value of 2.7°C and the maximum value of 10.2°C. Also, the percent of the additional load and the ratio of additional load to the evaporator load are analyzed.

  10. Experimental study of elliptical jet from sub to supercritical conditions

    Science.gov (United States)

    Muthukumaran, C. K.; Vaidyanathan, Aravind

    2014-04-01

    The jet mixing at supercritical conditions involves fluid dynamics as well as thermodynamic phenomena. All the jet mixing studies at critical conditions to the present date have focused only on axisymmetric jets. When the liquid jet is injected into supercritical environment, the thermodynamic transition could be well understood by considering one of the important fluid properties such as surface tension since it decides the existence of distinct boundary between the liquid and gaseous phase. It is well known that an elliptical liquid jet undergoes axis-switching phenomena under atmospheric conditions due to the presence of surface tension. The experimental investigations were carried out with low speed elliptical jet under supercritical condition. Investigation of the binary component system with fluoroketone jet and N2 gas as environment shows that the surface tension force dominates for a large downstream distance, indicating delayed thermodynamic transition. The increase in pressure to critical state at supercritical temperature is found to expedite the thermodynamic transition. The ligament like structures has been observed rather than droplets for supercritical pressures. However, for the single component system with fluoroketone jet and fluoroketone environment shows that the jet disintegrates into droplets as it is subjected to the chamber conditions even for the subcritical pressures and no axis switching phenomenon is observed. For a single component system, as the pressure is increased to critical state, the liquid jet exhibits gas-gas like mixing behavior and that too without exhibiting axis-switching behavior.

  11. Experimental study of elliptical jet from sub to supercritical conditions

    Energy Technology Data Exchange (ETDEWEB)

    Muthukumaran, C. K.; Vaidyanathan, Aravind, E-mail: aravind7@iist.ac.in [Department of Aerospace Engineering, Indian Institute of Space Science and Technology, Trivandrum, Kerala 695547 (India)

    2014-04-15

    The jet mixing at supercritical conditions involves fluid dynamics as well as thermodynamic phenomena. All the jet mixing studies at critical conditions to the present date have focused only on axisymmetric jets. When the liquid jet is injected into supercritical environment, the thermodynamic transition could be well understood by considering one of the important fluid properties such as surface tension since it decides the existence of distinct boundary between the liquid and gaseous phase. It is well known that an elliptical liquid jet undergoes axis-switching phenomena under atmospheric conditions due to the presence of surface tension. The experimental investigations were carried out with low speed elliptical jet under supercritical condition. Investigation of the binary component system with fluoroketone jet and N{sub 2} gas as environment shows that the surface tension force dominates for a large downstream distance, indicating delayed thermodynamic transition. The increase in pressure to critical state at supercritical temperature is found to expedite the thermodynamic transition. The ligament like structures has been observed rather than droplets for supercritical pressures. However, for the single component system with fluoroketone jet and fluoroketone environment shows that the jet disintegrates into droplets as it is subjected to the chamber conditions even for the subcritical pressures and no axis switching phenomenon is observed. For a single component system, as the pressure is increased to critical state, the liquid jet exhibits gas-gas like mixing behavior and that too without exhibiting axis-switching behavior.

  12. Meteorological Conditions Causing Jet-Engine Poweloss Events: Current Understanding

    Science.gov (United States)

    Strapp, J. W.; Ratvasky, T. P.

    2009-09-01

    The aviation industry is currently investigating a regular occurrence of jet engine-powerloss events which have now been attributed to the ingestion of atmospheric ice particles, usually in the vicinity of deep convection. There is a limited amount of information on the cloud microphysical properties near the cores of deep convection due to the potential hazards of flying in these areas, and due to the fact that it is a very challenging environment for current instrumentation. Most of the information that has been used to deduce the details of the conditions that cause engine powerloss has been extracted from the event-aircraft flight data recorders, pilot interviews, ground radar and satellite, a series of flight test programs in the 1950s and again in the 1990s, and the most recently available limited data from the cloud physics community. These have led to the conclusion that engine events occur due to flight through high mass concentrations of ice particles, probably with ice water contents (IWCs) in excess of 2 grams per cubic meter, and perhaps as high as 8. The limited microphysical data available has been used to suggest a median mass diameter of the ice particles of ~200 microns, with some evidence that it may be as low as 40 microns. These small particle sizes in the presence of high mass concentration is consistent with the lack of radar echoes > 20 dBZ observed on the pilot's radar, a consistent observation during engine events. The Engine Harmonization Working Group, an industry/regulator/government committee investigating engine powerloss, has concluded that the level of understanding of the properties of these clouds is inadequate to provide guidance to industry for engine design and testing. In order to address this issue, NASA and Environment Canada are planning to instrument an aircraft to make measurements in high IWC regions of tropical monsoon and continental convection. There is also a significant effort to upgrade and develop new

  13. Realizing life-scalable experimental pyroclastic density currents

    Science.gov (United States)

    Cronin, S. J.; Lube, G.; Breard, E.; Jones, J.; Valentine, G.; Freundt, A.; Hort, M. K.; Bursik, M. I.

    2013-12-01

    Pyroclastic Density Currents (PDCs) - the most deadly threat from volcanoes - are extremely hot, ground-hugging currents of rock fragments and gas that descend slopes at hundreds of kilometers per hour. These hostile flows are impossible to internally measure, thus volcanologists are persistently blocked in efforts to realistically forecast their internal mechanics and hazards. Attempts to fill this gap via laboratory-scale experiments continue to prove difficult, because they usually mismatch the dynamic and kinematic scaling of real-world flows by several orders of magnitude. In a multi-institutional effort, the first large-scale pyroclastic flow generator that can synthesize repeatable hot high-energy gas-particle mixture flows in safety has been commissioned in New Zealand. The final apparatus stands 15 m high, consisting of a tower/elevator system; an instrumented hopper that can hold >6000 kg (or 3.2 m3) of natural volcanic materials, which can be discharged at a range of controlled rates onto an instrumented, variably inclinable (6-25°) glass-sided chute for examining the vertical profiles of PDCs in motion. The use of rhyolitic pyroclastic material from the 1800 AD Taupo Eruption (with its natural grain-size, sorting and shape characteristics) and gas ensures natural coupling between the solids and fluid phases. PDC analogues with runout of >15 meters and flow depths of 1.5-6 meters are created by generating variably heated falling columns of natural volcanic particles (50-1300 kg/s), dispersed and aerated to controlled particle densities between 3 and 60 vol.% at the base of the elevated hopper. The descending columns rapidly generate high-velocity flows (up to 14 m/s) once impacting on the inclined channel, reproducing many features of natural flows, including segregation into dense and dilute regimes, progressive aggradational and en masse deposition of particles and the development of high internal gas-pore-pressures during flow. The PDC starting

  14. Electromagnetic characterization of current transformer with toroidal core under sinusoidal conditions

    Energy Technology Data Exchange (ETDEWEB)

    Koprivica, Branko, E-mail: branko.koprivica@ftn.kg.ac.rs; Milovanovic, Alenka, E-mail: alenka.milovanovic@ftn.kg.ac.rs

    2016-04-01

    The aim of this paper is to present a new procedure for the electromagnetic analysis of a measuring current transformer under sinusoidal conditions in its electrical and magnetic circuit. The influence of the magnetic hysteresis has been taken into account using the measured inverse magnetization curve and phase lag between the time waveforms of the magnetic field and the magnetic induction. Using the proposed analysis, ratio and phase errors of the current transformer have been calculated. The results of the calculation have been compared with experimental results and a good agreement has been found.

  15. Experimental study of blockage of monochromatic waves by counter currents

    NARCIS (Netherlands)

    Suastika, I.K.

    1999-01-01

    Blockage of waves by a current can occur if waves are propagating on a spatially varying opposing current in which the velocity is increasing in the wave propagation direction. The ongoing waves become shorter and steeper while they are propagating against the current. Blocking occurs at the

  16. Reinforcement learning accounts for moody conditional cooperation behavior: experimental results

    Science.gov (United States)

    Horita, Yutaka; Takezawa, Masanori; Inukai, Keigo; Kita, Toshimasa; Masuda, Naoki

    2017-01-01

    In social dilemma games, human participants often show conditional cooperation (CC) behavior or its variant called moody conditional cooperation (MCC), with which they basically tend to cooperate when many other peers have previously cooperated. Recent computational studies showed that CC and MCC behavioral patterns could be explained by reinforcement learning. In the present study, we use a repeated multiplayer prisoner’s dilemma game and the repeated public goods game played by human participants to examine whether MCC is observed across different types of game and the possibility that reinforcement learning explains observed behavior. We observed MCC behavior in both games, but the MCC that we observed was different from that observed in the past experiments. In the present study, whether or not a focal participant cooperated previously affected the overall level of cooperation, instead of changing the tendency of cooperation in response to cooperation of other participants in the previous time step. We found that, across different conditions, reinforcement learning models were approximately as accurate as a MCC model in describing the experimental results. Consistent with the previous computational studies, the present results suggest that reinforcement learning may be a major proximate mechanism governing MCC behavior. PMID:28071646

  17. Reinforcement learning accounts for moody conditional cooperation behavior: experimental results.

    Science.gov (United States)

    Horita, Yutaka; Takezawa, Masanori; Inukai, Keigo; Kita, Toshimasa; Masuda, Naoki

    2017-01-10

    In social dilemma games, human participants often show conditional cooperation (CC) behavior or its variant called moody conditional cooperation (MCC), with which they basically tend to cooperate when many other peers have previously cooperated. Recent computational studies showed that CC and MCC behavioral patterns could be explained by reinforcement learning. In the present study, we use a repeated multiplayer prisoner's dilemma game and the repeated public goods game played by human participants to examine whether MCC is observed across different types of game and the possibility that reinforcement learning explains observed behavior. We observed MCC behavior in both games, but the MCC that we observed was different from that observed in the past experiments. In the present study, whether or not a focal participant cooperated previously affected the overall level of cooperation, instead of changing the tendency of cooperation in response to cooperation of other participants in the previous time step. We found that, across different conditions, reinforcement learning models were approximately as accurate as a MCC model in describing the experimental results. Consistent with the previous computational studies, the present results suggest that reinforcement learning may be a major proximate mechanism governing MCC behavior.

  18. Experimental FSO network availability estimation using interactive fog condition monitoring

    Science.gov (United States)

    Turán, Ján.; Ovseník, Łuboš

    2016-12-01

    Free Space Optics (FSO) is a license free Line of Sight (LOS) telecommunication technology which offers full duplex connectivity. FSO uses infrared beams of light to provide optical broadband connection and it can be installed literally in a few hours. Data rates go through from several hundreds of Mb/s to several Gb/s and range is from several 100 m up to several km. FSO link advantages: Easy connection establishment, License free communication, No excavation are needed, Highly secure and safe, Allows through window connectivity and single customer service and Compliments fiber by accelerating the first and last mile. FSO link disadvantages: Transmission media is air, Weather and climate dependence, Attenuation due to rain, snow and fog, Scattering of laser beam, Absorption of laser beam, Building motion and Air pollution. In this paper FSO availability evaluation is based on long term measured data from Fog sensor developed and installed at TUKE experimental FSO network in TUKE campus, Košice, Slovakia. Our FSO experimental network has three links with different physical distances between each FSO heads. Weather conditions have a tremendous impact on FSO operation in terms of FSO availability. FSO link availability is the percentage of time over a year that the FSO link will be operational. It is necessary to evaluate the climate and weather at the actual geographical location where FSO link is going to be mounted. It is important to determine the impact of a light scattering, absorption, turbulence and receiving optical power at the particular FSO link. Visibility has one of the most critical influences on the quality of an FSO optical transmission channel. FSO link availability is usually estimated using visibility information collected from nearby airport weather stations. Raw data from fog sensor (Fog Density, Relative Humidity, Temperature measured at each ms) are collected and processed by FSO Simulator software package developed at our Department. Based

  19. Experimental Study on Current-Driven Domain Wall Motion

    Science.gov (United States)

    Ono, T.; Yamaguchi, A.; Tanigawa, H.; Yano, K.; Kasai, S.

    2006-06-01

    Current-driven domain wall (DW) motion for a well-defined single DW in a micro-fabricated magnetic wire with submicron width was investigated by real-space observation with magnetic force microscopy. Magnetic force microscopy visualizes that a single DW introduced in a wire is displaced back and forth by positive and negative pulsed-current, respectively. Effect of the Joule heating, reduction of the threshold current density by shape control, and magnetic ratchet effect are also presented.

  20. Effect of Operating Conditions on CSTR performance: an Experimental Study

    Directory of Open Access Journals (Sweden)

    Mohd Danish

    2015-02-01

    Full Text Available In this work, Saponification reaction of ethyl acetate by sodium hydroxide is studied experimentally in a continuous stirred tank reactor at 1 atmospheric pressure. The aim of this study is to investigate the influence of operating conditions on the conversion and specific rate constant. The parameters considered for analysis are temperature, feed flow rate, residence time, volume of reactor and stirrer rate. The steady state conversion of 0.45 achieved after a period of 30 minutes. Conversion decreases with increase of reactant flow rate due to decrease of residence time. The stirrer rate has a positive effect on the conversion and rate constant. Specific rate constant and conversion increase with temperature within the studied temperature range. Within the range of reactor volume selected for analysis, conversion increases with increase in reactor volume. The results obtained in this study may be helpful in maximizing the conversion of ethyl acetate saponification reaction at industrial scale in a CSTR.

  1. Experimental Verification of Steel Pipe Collapse under Vacuum Pressure Conditions

    Science.gov (United States)

    Autrique, R.; Rodal, E.

    2016-11-01

    Steel pipes are used widely in hydroelectric systems and in pumping systems. Both systems are subject to hydraulic transient effects caused by changes in boundary conditions, such as sudden valve closures, pump failures, or accidents. Water column separation, and its associated vaporization pressure inside the pipe, can cause the collapse of thin walled steel pipes subject to atmospheric pressure, as happened during the well known Oigawa Power Plant accident in Japan, in 1950. The conditions under which thin walled pipes subject to external pressure can collapse have been studied mathematically since the second half of the XIX century, with classical authors Southwell and Von Mises obtaining definitive equations for long and short pipes in the second decade of the XX century, in which the fundamental variables are the diameter to thickness ratio D/t and the length to diameter ratio L/D. In this paper, the predicted critical D/t ratio for steel pipe collapse is verified experimentally, in a physical model able to reproduce hydraulic transients, generating vacuum pressures through rapid upstream valve closures.

  2. Experimental study of choking flow of water at supercritical conditions

    Science.gov (United States)

    Muftuoglu, Altan

    Future nuclear reactors will operate at a coolant pressure close to 25 MPa and at outlet temperatures ranging from 500°C to 625°C. As a result, the outlet flow enthalpy in future Supercritical Water-Cooled Reactors (SCWR) will be much higher than those of actual ones which can increase overall nuclear plant efficiencies up to 48%. However, under such flow conditions, the thermal-hydraulic behavior of supercritical water is not fully known, e.g., pressure drop, forced convection and heat transfer deterioration, critical and blowdown flow rate, etc. Up to now, only a very limited number of studies have been performed under supercritical conditions. Moreover, these studies are conducted at conditions that are not representative of future SCWRs. In addition, existing choked flow data have been collected from experiments at atmospheric discharge pressure conditions and in most cases by using working fluids different than water which constrain researchers to analyze the data correctly. In particular, the knowledge of critical (choked) discharge of supercritical fluids is mandatory to perform nuclear reactor safety analyses and to design key mechanical components (e.g., control and safety relief valves, etc.). Hence, an experimental supercritical water facility has been built at Ecole Polytechnique de Montreal which allows researchers to perform choking flow experiments under supercritical conditions. The facility can also be used to carry out heat transfer and pressure drop experiments under supercritical conditions. In this thesis, we present the results obtained at this facility using a test section that contains a 1 mm inside diameter, 3.17 mm long orifice plate with sharp edges. Thus, 545 choking flow of water data points are obtained under supercritical conditions for flow pressures ranging from 22.1 MPa to 32.1 MPa, flow temperatures ranging from 50°C to 502°C and for discharge pressures from 0.1 MPa to 3.6 MPa. Obtained data are compared with the data given in

  3. EXPERIMENTAL STUDY ON BED-LOAD SEDIMENT TRANSPORT IN IRREGULAR WAVE-CURRENT COEXISTENT FIELD

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    In order to evaluate bed-load sediment transport in an irregular wave-current coexistent field, a series of experiments were completed in laboratory with an irregularly oscillating tray, which was specially designed to simulate the irregular wave-current coexistent field. Experimental results are presented on the initial motion of sediment and the rates of transport over flat horizontal bed. Testing conditions included three interaction angles, 0°, 45°, 90° and six kinds of grain sizes. Four kinds (0.2mm, 0.46mm, 0.85mm and 1.3mm) were used for the tests of initial motion, while the other two kinds (0.38mm and 1.1mm) for the tests of transport rate. Comparisons between experimental results of initial motion and modified Shields curve indicate that the Shields curve is still valid for the case of irregular wave-current coexistent field. Analysis of flow regime shows that initial conditions fall within smooth-turbulent transitional region. The results of transport rate show us that net sediment transport rate can be expressed approximately as the function of the maximum bottom shear stress and mean shear stress. A dimensionless formula is proposed on the basis of mechanism "Waves erode sediments, tides transport sediments".

  4. Coupling currents in Rutherford cables under time varying conditions

    NARCIS (Netherlands)

    Verweij, A.P.; Kate, ten H.H.J.

    1993-01-01

    A network model is presented to simulate fully transposed Rutherford cables under time varying conditions. The intrinsic properties of the cable and the external applied conditions can be changed spatially. Several statistical distributions of the contact resistances are built in to investigate loca

  5. Current experimental situation in heavy-ion reactions

    Energy Technology Data Exchange (ETDEWEB)

    Scott, D.K.

    1978-06-01

    A detailed survey of the present experimental situation in heavy-ion physics is presented. The discussion begins by considering the simple excitation of discrete states in elastic scattering, transfer, and compound-nucleus reactions; it then turns to more drastic perturbations of the nucleus high in the continuum through fusion, fission, and deeply inelastic scattering, and concludes with the (possibly) limiting asymptotic phenomena of relativistic heavy-ion collisions. 138 figures, 5 tables, 451 references. (RWR)

  6. Replacement Condition Detection of Railway Point Machines Using an Electric Current Sensor.

    Science.gov (United States)

    Sa, Jaewon; Choi, Younchang; Chung, Yongwha; Kim, Hee-Young; Park, Daihee; Yoon, Sukhan

    2017-01-29

    Detecting replacement conditions of railway point machines is important to simultaneously satisfy the budget-limit and train-safety requirements. In this study, we consider classification of the subtle differences in the aging effect-using electric current shape analysis-for the purpose of replacement condition detection of railway point machines. After analyzing the shapes of after-replacement data and then labeling the shapes of each before-replacement data, we can derive the criteria that can handle the subtle differences between "does-not-need-to-be-replaced" and "needs-to-be-replaced" shapes. On the basis of the experimental results with in-field replacement data, we confirmed that the proposed method could detect the replacement conditions with acceptable accuracy, as well as provide visual interpretability of the criteria used for the time-series classification.

  7. Optimisation of Experimental Conditions for Ex-Bed Desulfurization

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez, J. M.; Ruiz, E.; Otero, J.

    2010-12-22

    This report compiles the results of the work conducted by CIEMAT for Task 6.3 Sulfur and Nitrogen Compounds Abatement of the FLEXGAS project Near Zero Emission Advanced Fluidized Bed Gasification, which has been carried out with financial support from the Research Fund for Coal and Steel, RFCR-CT-2007-00005. The assignment of CIEMAT in Task 6.3 has dealt with the experimental study of ex-bed desulfurization at high temperature and high pressure. Based on a review of the state of the art, a zinc oxide sorbent was chosen as a promising candidate for bulk sulfur removal in highly reducing gases such as those from coal and waste oxygen gasification or for a polishing stage in low sulfur content gases, which is typically the case in biomass gasification gases. The work accomplished has included the study of the sulfidation and regeneration stages in order to determine successful operating conditions and the assessment of the long term performance of the sorbent over subsequent sulfidation and regeneration cycles. (Author) 36 refs.

  8. Erythropoietin regulations in humans under different environmental and experimental conditions.

    Science.gov (United States)

    Gunga, H-C; Kirsch, K A; Roecker, L; Kohlberg, E; Tiedemann, J; Steinach, M; Schobersberger, W

    2007-09-30

    In the adult human, the kidney is the main organ for the production and release of erythropoietin (EPO). EPO is stimulating erythropoiesis by increasing the proliferation, differentiation and maturation of the erythroid precursors. In the last decades, enormous efforts were made in the purification, molecular encoding and description of the EPO gene. This led to an incredible increase in the understanding of the EPO-feedback-regulation loop at a molecular level, especially the oxygen-dependent EPO gene expression, a key function in the regulation loop. However, studies in humans at a systemic level are still very scanty. Therefore, it is the purpose of the present review to report on the main recent investigations on EPO production and release in humans under different environmental and experimental conditions, including: (i) studies on EPO circadian, monthly and even annual variations, (ii) studies in connection with short-, medium- and long-term exercise at sea-level which will be followed (iii) by studies performed at moderate and high altitude.

  9. Experimental Verification of Current Shear Design Equations for HSRC Beams

    Directory of Open Access Journals (Sweden)

    Attaullah Shah

    2012-07-01

    Full Text Available Experimental research on the shear capacity of HSRC (High Strength Reinforced Concrete beams is relatively very limited as compared to the NSRC (Normal Strength Reinforced Concrete beams. Most of the Building Codes determine the shear strength of HSRC with the help of empirical equations based on experimental work of NSRC beams and hence these equations are generally regarded as un-conservative for HSRC beams particularly at low level of longitudinal reinforcement. In this paper, 42 beams have been tested in two sets, such that in 21 beams no transverse reinforcement has been used, whereas in the remaining 21 beams, minimum transverse reinforcement has been used as per ACI-318 (American Concrete Institute provisions. Two values of compressive strength 52 and 61 MPa, three values of longitudinal steel ratio and seven values of shear span to depth ratio have been have been used. The beams were tested under concentrated load at the mid span. The results are compared with the equations proposed by different international building codes like ACI, AASHTO LRFD, EC (Euro Code, Canadian Code and Japanese Code for shear strength of HSRC beams.From comparison, it has been observed that some codes are less conservative for shear design of HSRC beams and further research is required to rationalize these equations.

  10. Experimental Study on Current Decay Characteristics of Persistent Current HTS Magnet by Alternating Magnetic Field

    Science.gov (United States)

    Park, Young Gun; Lee, Chang Young; Hwang, Young Jin; Lee, Woo Seung; Lee, Jiho; Jo, Hyun Chul; Chung, Yoon Do; Ko, Tae Kuk

    This paper deals with a current decay characteristics of a high temperature superconducting (HTS) magnet operated in persistent current mode (PCM). In superconducting synchronous machine applications such as linear synchronous motor (LSM), the superconducting coil is designed to operate in the PCM to obtain steady magnetic field with DC transport current. This superconducting magnet operates on a direct current, but it can be exposed to alternating magnetic field due to the armature winding. When the magnet is subjected to an external time-varying magnetic field, it is possible to result in a decay of the current in PCM system due to AC loss. In this research, a PCM system with armature coil which generates time-varying magnetic field was fabricated to verify current decay characteristics by external alternating magnetic field. The current decay rate was measured by using a hall sensor as functions of amplitude and frequency of armature coil.

  11. Review of experimental data for modelling LWR fuel cladding behaviour under loss of coolant accident conditions

    Energy Technology Data Exchange (ETDEWEB)

    Massih, Ali R. [Quantum Technologies AB, Uppsala Science Park (Sweden)

    2007-02-15

    Extensive range of experiments has been conducted in the past to quantitatively identify and understand the behaviour of fuel rod under loss-of-coolant accident (LOCA) conditions in light water reactors (LWRs). The obtained experimental data provide the basis for the current emergency core cooling system acceptance criteria under LOCA conditions for LWRs. The results of recent experiments indicate that the cladding alloy composition and high burnup effects influence LOCA acceptance criteria margins. In this report, we review some past important and recent experimental results. We first discuss the background to acceptance criteria for LOCA, namely, clad embrittlement phenomenology, clad embrittlement criteria (limitations on maximum clad oxidation and peak clad temperature) and the experimental bases for the criteria. Two broad kinds of test have been carried out under LOCA conditions: (i) Separate effect tests to study clad oxidation, clad deformation and rupture, and zirconium alloy allotropic phase transition during LOCA. (ii) Integral LOCA tests, in which the entire LOCA sequence is simulated on a single rod or a multi-rod array in a fuel bundle, in laboratory or in a tests and results are discussed and empirical correlations deduced from these tests and quantitative models are conferred. In particular, the impact of niobium in zirconium base clad and hydrogen content of the clad on allotropic phase transformation during LOCA and also the burst stress are discussed. We review some recent LOCA integral test results with emphasis on thermal shock tests. Finally, suggestions for modelling and further evaluation of certain experimental results are made.

  12. Transmission rate of African swine fever virus under experimental conditions.

    Science.gov (United States)

    de Carvalho Ferreira, H C; Backer, J A; Weesendorp, E; Klinkenberg, D; Stegeman, J A; Loeffen, W L A

    2013-08-30

    African swine fever (ASF) is a highly lethal, viral disease of swine. No vaccine is available, so controlling an ASF outbreak is highly dependent on zoosanitary measures, such as stamping out infected herds and quarantining of affected areas. Information on ASF transmission parameters could allow for more efficient application of outbreak control measures. Three transmission experiments were carried out to estimate the transmission parameters of two ASF virus isolates: Malta'78 (in two doses) and Netherlands'86. Different criteria were used for onset of infectiousness of infected pigs and moment of infection of contact pigs. The transmission rate (β), estimated by a Generalized Linear Model, ranged from 0.45 to 3.63 per day. For the infectious period, a minimum as well as a maximum infectious period was determined, to account for uncertainties regarding infectiousness of persistently infected pigs. While the minimum infectious period ranged from 6 to 7 days, the average maximum infectious period ranged from approximately 20 to nearly 40 days. Estimates of the reproduction ratio (R) for the first generation of transmission ranged from 4.9 to 24.2 for the minimum infectious period and from 9.8 to 66.3 for the maximum infectious period, depending on the isolate. A first approximation of the basic reproduction ratio (R0) resulted in an estimate of 18.0 (6.90-46.9) for the Malta'78 isolate. This is the first R0 estimate of an ASFV isolate under experimental conditions. The estimates of the transmission parameters provide a quantitative insight into ASFV epidemiology and can be used for the design and evaluation of more efficient control measures.

  13. Experimental investigation of current free double layers in helicon plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Sahu, B. B. [Department of Applied Sciences and Humanities, Dronacharya College of Engineering, Gurgaon 123506 (India); Tarey, R. D. [Department of Physics, Indian Institute of Technology, New Delhi 110016 (India); Ganguli, A. [Centre for Energy Studies, Indian Institute of Technology, New Delhi 110016 (India)

    2014-02-15

    The paper presents investigations of current free double layer (CFDL) that forms in helicon plasmas. In contrast to the other work reporting on the same subject, in the present investigations the double layer (DL) forms in a mirror-like magnetic field topology. The RF compensated Langmuir probe measurements show multiple DLs, which are in connection with, the abrupt fall of densities along with potential drop of about 24 V and 18 V. The DLs strengths (e ΔV{sub p})/(k T{sub e}) are about 9.5 and 6, and the corresponding widths are about 6 and 5 D lengths. The potential drop is nearly equal to the thermal anisotropies between the two plasma regions forming the DL, which is present in the plateau region of mirror, unlike the earlier studies on the DL formation in the region of strong gradients in the magnetic field. Also, it presents a qualitative discussion on the mechanism of DL formation.

  14. Safety and efficacy of transcranial direct current stimulation in acute experimental ischemic stroke.

    Science.gov (United States)

    Peruzzotti-Jametti, Luca; Cambiaghi, Marco; Bacigaluppi, Marco; Gallizioli, Mattia; Gaude, Edoardo; Mari, Silvia; Sandrone, Stefano; Cursi, Marco; Teneud, Luis; Comi, Giancarlo; Musco, Giovanna; Martino, Gianvito; Leocani, Letizia

    2013-11-01

    Transcranial direct current stimulation is emerging as a promising tool for the treatment of several neurological conditions, including cerebral ischemia. The therapeutic role of this noninvasive treatment is, however, limited to chronic phases of stroke. We thus ought to investigate whether different stimulation protocols could also be beneficial in the acute phase of experimental brain ischemia. The influence of both cathodal and anodal transcranial direct current stimulation in modifying brain metabolism of healthy mice was first tested by nuclear magnetic resonance spectroscopy. Then, mice undergoing transient proximal middle cerebral artery occlusion were randomized and treated acutely with anodal, cathodal, or sham transcranial direct current stimulation. Brain metabolism, functional outcomes, and ischemic lesion volume, as well as the inflammatory reaction and blood brain barrier functionality, were analyzed. Cathodal stimulation was able, if applied in the acute phase of stroke, to preserve cortical neurons from the ischemic damage, to reduce inflammation, and to promote a better clinical recovery compared with sham and anodal treatments. This finding was attributable to the significant decrease of cortical glutamate, as indicated by nuclear magnetic resonance spectroscopy. Conversely, anodal stimulation induced an increase in the postischemic lesion volume and augmented blood brain barrier derangement. Our data indicate that transcranial direct current stimulation exerts a measurable neuroprotective effect in the acute phase of stroke. However, its timing and polarity should be carefully identified on the base of the pathophysiological context to avoid potential harmful side effects.

  15. An experimental test of condition-dependent male and female mate choice in zebra finches.

    Directory of Open Access Journals (Sweden)

    Marie-Jeanne Holveck

    Full Text Available In mating systems with social monogamy and obligatory bi-parental care, such as found in many songbird species, male and female fitness depends on the combined parental investment. Hence, both sexes should gain from choosing mates in high rather than low condition. However, theory also predicts that an individual's phenotypic quality can constrain choice, if low condition individuals cannot afford prolonged search efforts and/or face higher risk of rejection. In systems with mutual mate choice, the interaction between male and female condition should thus be a better predictor of choice than either factor in isolation. To address this prediction experimentally, we manipulated male and female condition and subsequently tested male and female mating preferences in zebra finches Taeniopygia guttata, a songbird species with mutual mate choice and obligatory bi-parental care. We experimentally altered phenotypic quality by manipulating the brood size in which the birds were reared. Patterns of association for high- or low-condition individuals of the opposite sex differed for male and female focal birds when tested in an 8-way choice arena. Females showed repeatable condition-assortative preferences for males matching their own rearing background. Male preferences were also repeatable, but not predicted by their own or females' rearing background. In combination with a brief review of the literature on condition-dependent mate choice in the zebra finch we discuss whether the observed sex differences and between-studies differences arise because males and females differ in context sensitivity (e.g. male-male competition suppressing male mating preferences, sampling strategies or susceptibility to rearing conditions (e.g. sex-specific effect on physiology. While a picture emerges that juvenile and current state indeed affect preferences, the development and context-dependency of mutual state-dependent mate choice warrants further study.

  16. Inactivation of VHSV by Percolation and Salt Under Experimental Conditions

    DEFF Research Database (Denmark)

    Skall, Helle Frank; Olesen, Niels Jørgen; Jørgensen, Claus

    2012-01-01

    At the moment the only legal method in Denmark to sanitize wastewater from fish cutting plants is by percolation. To evaluate the inactivation effect of percolation on VHSV an experimental examination was initiated. A column packed with gravel as top- and bottom layer (total of 22 cm) and a mid l...

  17. Psychoimmunomodulating activity of Phenibut under conditions of experimental hyperthyroidism

    Directory of Open Access Journals (Sweden)

    M A Samotrueva

    2012-03-01

    Full Text Available Psychoimmunomodulating action of Phenibut has been shown on the model of experimental hyperthyroidism. It has been found that the drug (intra-abdominal injection in the dose 25 mg/kg is able to restore humoral immunoreactivity and liquidate disturbances of the behaviour reactions appearing in the result of induced pathology as well.

  18. Experimental tests of a gas fired adsorption air conditioning system

    Energy Technology Data Exchange (ETDEWEB)

    Poyelle, F.; Guilleminot, J.J.; Meunier, F. [C.N.R.S.-L.I.M.S.I., Orsay Cedex (France); Canal, P.; Soide, I.; Klemsdal, E. [Gaz de Francer Saint Denis La Plaine (France)

    1997-10-01

    Over recent years, there has been growing interest for air conditioning systems, for commercial and offices buildings, transport and residential houses. Gaz de France promote natural gas powered air conditioning systems through the installation of commercial absorption machines, producing chilled and/or hot water. These machines cover loads from 70 kW to 5 MW. Gaz de France`s purpose is to develop a small scale natural gas fueled air conditioning system for residential applications and small commercials (5-20 kW). In order to study the feasibility of a small scale adsorption machine, a prototype has been studied, designed, constructed and tested. (au) 11 refs.

  19. Experimental diabetes induced by alloxan and streptozotocin: The current state of the art.

    Science.gov (United States)

    Radenković, Miroslav; Stojanović, Marko; Prostran, Milica

    2016-01-01

    Diabetes mellitus is a chronic metabolic disorder with a high prevalence worldwide. Animal models of diabetes represent an important tool in diabetes investigation that helps us to avoid unnecessary and ethically challenging studies in human subjects, as well as to obtain a comprehensive scientific viewpoint of this disease. Although there are several methods through which diabetes can be induced, chemical methods of alloxan- and streptozotocin-induced diabetes represent the most important and highly preferable experimental models for this pathological condition. Therefore, the aim of this article was to review the current knowledge related to quoted models of diabetes, including to this point available information about mechanism of action, particular time- and dose-dependent protocols, frequent problems, as well as major limitations linked to laboratory application of alloxan and sterptozotocin in inducing diabetes. Given that diabetes is known to be closely associated with serious health consequences it is of fundamental importance that current animal models for induction of diabetes should be continuously upgraded in order to improve overall prevention, diagnosis and treatment of this pathological condition.

  20. Experimental studies of pedestrian flows under different boundary conditions

    CERN Document Server

    Zhang, Jun

    2015-01-01

    In this article the dynamics of pedestrian streams in four different scenarios are compared empirically to investigate the influence of boundary conditions on it. The Voronoi method, which allows high resolution and small fluctuations of measured density in time and space, is used to analyze the experiments. It is found that pedestrian movement in systems with different boundary conditions (open, periodic boundary conditions and outflow restrained) presents various characteristics especially when the density is larger than 2 m-2. In open corridor systems the specific flow increases continuously with increasing density till 4 m-2. The specific flow keeps constant in systems with restrained outflow, whereas it decreases from 1 (m.s)-1 to zero in system with closed periodical condition.

  1. Experimental Study on Allowable Berthing and Mooring Conditions of An Oil Tanker

    Institute of Scientific and Technical Information of China (English)

    张日向; 刘忠波; 张宁川; 韩丽华

    2003-01-01

    When an oil tanker under the combined action of wind, waves and tidal current and is berthed or moored to a platform, the impact forces on the fenders and the tensile force in the mooring lines are important factors in the studies of berthing and mooring conditions. Based on the experiment of a berthing and mooring tanker model under the action of wind, wave and tidal current in the same direction, this paper studies the allowable berthing and mooring conditions by considering the tensile forces of mooring lines and impact forces on the fenders, as well as the impact energy on the fenders. And a method has been proposed here for motion amplitude analysis. A successful method to decrease impact forces on the fenders is put forward. Blowing-in wind and blowing-off wind and different angles between waves and the fenders are considered in the experimental study. In the berthing tests of the tanker model, the impact forces are measured and the impact energy is calculated, then the berthing conditions are determined. In the mooring tests of the tanker model, the mooring line tensile forces and impact forces are measured, and the allowable mooring conditions are given that will be useful to engineering design.

  2. A quantitative assessment of the effectiveness of PRRSV vaccination in pigs under experimental conditions

    NARCIS (Netherlands)

    Nodelijk, G.; Jong, de M.C.M.; Leengoed, van L.A.M.G.; Wensvoort, G.; Pol, J.M.A.; Steverink, P.J.G.M.; Verheijden, J.H.M.

    2001-01-01

    This paper presents a quantitative approach to evaluate effectiveness of vaccination under experimental conditions. We used two consecutive experimental designs to investigate whether PRRSV transmission among vaccinated pigs was reduced compared to control pigs and to estimate the reproduction param

  3. Inactivation of VHSV by Percolation and Salt Under Experimental Conditions

    OpenAIRE

    Skall, Helle Frank; Olesen, Niels Jørgen; Jørgensen, Claus

    2012-01-01

    At the moment the only legal method in Denmark to sanitize wastewater from fish cutting plants is by percolation. To evaluate the inactivation effect of percolation on VHSV an experimental examination was initiated. A column packed with gravel as top- and bottom layer (total of 22 cm) and a mid layer consisting of dug sand (76 cm) was used for the trial. Over a period of 18 h 3.9 x 1010 TCID50 VHSV was supplied to the column, where after normal tap water was supplied for the rest of the trial...

  4. Inactivation of VHSV by infiltration and salt under experimental conditions

    OpenAIRE

    Skall, Helle Frank; Jørgensen, Claus; Olesen, Niels Jørgen

    2014-01-01

    At the moment the only legal method in Denmark to sanitize wastewater from fish cutting plants is by infiltration. To evaluate the inactivation effect of infiltration on VHSV an experimental examination was initiated. A column packed with gravel as top- and bottom layer (total of 22 cm) and a mid layer consisting of dug sand (76 cm) was used for the trial. Over a period of 18 h 3.9 x 1010 TCID50 VHSV was supplied to the column, where after normal tap water was supplied for the rest of the tri...

  5. Zeros and poles of quantum current operators and the condition of quantum integrability

    CERN Document Server

    Ding, J; Ding, Jintai; Miwa, Tetsuji

    1996-01-01

    For the current realization of the affine quantum groups, a simple comultiplication for the quantum current operators was given by Drinfeld. With this comultiplication, we study the zeros and poles of the quantum current operators and present a condition of integrability on the quantum current of $U_q\\left(\\hat{\\frak sl}(2)\\right)$, which is a deformation of the corresponding condition for $\\hat{\\frak sl}(2)$.

  6. Exploring the proper experimental conditions in 2D thermal cloaking demonstration

    Science.gov (United States)

    Hu, Run; Zhou, Shuling; Yu, Xingjian; Luo, Xiaobing

    2016-10-01

    Although thermal cloak has been studied extensively, the specific discussions on the proper experimental conditions to successfully observe the thermal cloaking effect are lacking. In this study, we focus on exploring the proper experimental conditions for 2D thermal cloaking demonstration. A mathematical model is established and detailed discussions are presented based on the model. The proper experimental conditions are suggested and verified with finite element simulations.

  7. Currents, HF Radio-derived, Monterey Bay, 1 hr, Meridional, EXPERIMENTAL

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The data is the 1 hour average of the meridional component of ocean surface currents derived from High Frequency Radio-derived measurements. THIS IS AN EXPERIMENTAL...

  8. Currents, HF Radio-derived, SF Bay, 1 hr, Zonal, EXPERIMENTAL

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The data is the 1 hour average of the zonal component of ocean surface currents derived from High Frequency Radio-derived measurements. THIS IS AN EXPERIMENTAL...

  9. Currents, HF Radio-derived, SF Bay Outlet, 1 hr, Zonal, EXPERIMENTAL

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The data is the 1 hour average of the zonal component of ocean surface currents derived from High Frequency Radio-derived measurements. THIS IS AN EXPERIMENTAL...

  10. Currents, HF Radio-derived, SF Bay Outlet, 1 hr, Meridional, EXPERIMENTAL

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The data is the 1 hour average of the meridional component of ocean surface currents derived from High Frequency Radio-derived measurements. THIS IS AN EXPERIMENTAL...

  11. Currents, HF Radio-derived, Bodega Bay, 1 hr, Meridional, EXPERIMENTAL

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The data is the 1 hour average of the meridional component of ocean surface currents derived from High Frequency Radio-derived measurements. THIS IS AN EXPERIMENTAL...

  12. Currents, HF Radio-derived, Bodega Bay, 1 hr, Zonal, EXPERIMENTAL

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The data is the 1 hour average of the zonal component of ocean surface currents derived from High Frequency Radio-derived measurements. THIS IS AN EXPERIMENTAL...

  13. Currents, HF Radio-derived, Ano Nuevo, 1 hr, Zonal, EXPERIMENTAL

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The data is the 1 hour average of the zonal component of ocean surface currents derived from High Frequency Radio-derived measurements. THIS IS AN EXPERIMENTAL...

  14. Currents, HF Radio-derived, Ano Nuevo, 1 hr, Meridional, EXPERIMENTAL

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The data is the 1 hour average of the meridional component of ocean surface currents derived from High Frequency Radio-derived measurements. THIS IS AN EXPERIMENTAL...

  15. Experimental characterization of hohlraum conditions by X-ray spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Back, C.A.; Hsieh, E.J.; Kauffman, R.L. [and others

    1996-06-01

    Spectroscopy is a powerful technique used to measure the plasma parameters relevant to Inertial Confinement Fusion (ICF) plasmas. For instance, the onset of spectral signals from multilayer targets have been used to determine ablation rate scalings. Temperature and density measurements in coronal plasmas have enabled the study of laser coupling efficiency as a function of the laser wavelengths. More recently, dopants have been successfully used to determine capsule conditions of ICF targets. However, few spectroscopic studies have been performed to diagnose plasma conditions of the hohlraum itself. Several laboratories have studied enclosed cavities, previously concentrating on measurements of the radiative heat wave, the x-ray conversion efficiency, and temporal evolution of Au x rays. Measurements of electron temperature T{sub e} and electron densities n{sub e} are difficult because many physical processes occur and each diagnostic`s line-of-sight is restricted by the hohlraum wall. However, they are worth pursuing because they can provide critical information on the target energetics and the evolution of plasma parameters important to achieving fusion. Here the authors discuss spectroscopic tracers to diagnose plasma conditions in the hohlraum, using time- and space-resolved measurements. The tracers are typically mid-Z elements which are placed on the hohlraum wall or supended in the hohlraum volume. To demonstrate the breadth of measurements that can be performed, three types of experiments are presented.

  16. Experimental characterization of materials subjected to combined loading conditions

    Science.gov (United States)

    Andrusca, L.; Goanta, V.; Barsanescu, P. D.; Savin, A.

    2016-08-01

    In real life experience, machine and structure elements are subjected to complex loading history. Combined loading testes facilitate the understanding of materials behavior subjected to multiaxial stress state. In this paper are presented experimental investigations used to evaluate the influence of an initial type of loading on material properties which will be subsequently tested through another load type. Initial tests are tension tests, by different elongations, and subsequent tests are torsion tests, until break. Circular cross section specimens will be used in these tests. Tension tests have been performed on a universal testing machine. Subsequently torsion tests have been conducted through an attachable device. It was found that the energy associated with plastic deformation obtained by subsequent torsional tests has the dominant influence on the material total plastic energy, although initial test was tension.

  17. Experimental Evidence of Classical Conditioning and Microscopic Engrams in an Electroconductive Material

    Science.gov (United States)

    Karbowski, Lukasz M.; Persinger, Michael A.

    2016-01-01

    Synthetic experimental substrates are indispensable tools which can allow researchers to model biological processes non-invasively in three-dimensional space. In this study, we investigated the capacities of an electroconductive material whose properties converge upon those of the brain. An electrically conductive material composed of carbohydrates, proteins, fats, ions, water, and trace amounts of other organic compounds and minerals was classically conditioned as inferred by electrophysiological measurements. Spectral densities evoked during the display of a conditioned stimulus (CS) probe were strongly congruent with those displayed during the conditioned-unconditioned stimulus pairing (CS-UCS). The neutral stimulus consisted of the pulsed light from a LED. The unconditioned stimulus was an alternating current. Interstimulus intervals >130 ms did not result in conditioned responses. Microscopic analysis of the chemically-fixed substratum revealed 10–200 μm wide ‘vessel structures’ within samples exposed to a stimulus. Greater complexity (increased fractal dimensions) was clearly discernable by light microscopy for stained sections of fixed samples that had been conditioned compared to various controls. The denser pixels indicated greater concentration of stain and increased canalization. Implications for learning and memory formation are discussed. PMID:27764215

  18. Experimental observation of wiggler superradiance under group synchronism condition

    CERN Document Server

    Ginzburg, N S; Zotova, I V; Sergeev, A S; Phelps, A D R; Cross, A W; He, W; Ronald, K; Shpak, V G; Yalandin, M I; Shunailov, S A; Ulmaskulov, M R

    1999-01-01

    The first results of the observation of superradiance from a single, subnanosecond, high current, electron bunch passing through a wiggler immersed in a guide magnetic field are presented. The 300-500 ps microwave pulses were generated in the high gain regime for both the conventional and reverse directions of the guide magnetic field. The dependence of the radiation power on the interaction length as well as the absolute value of the power, 100-200 kW, were related with the development of self-bunching and consequently with coherent emission.

  19. Experimental pain processing in individuals with cognitive impairment: current state of the science.

    Science.gov (United States)

    Defrin, Ruth; Amanzio, Martina; de Tommaso, Marina; Dimova, Violeta; Filipovic, Sasa; Finn, David P; Gimenez-Llort, Lydia; Invitto, Sara; Jensen-Dahm, Christina; Lautenbacher, Stefan; Oosterman, Joukje M; Petrini, Laura; Pick, Chaim G; Pickering, Gisele; Vase, Lene; Kunz, Miriam

    2015-08-01

    Cognitive impairment (CI) can develop during the course of ageing and is a feature of many neurological and neurodegenerative diseases. Many individuals with CI have substantial, sustained, and complex health care needs, which frequently include pain. However, individuals with CI can have difficulty communicating the features of their pain to others, which in turn presents a significant challenge for effective diagnosis and treatment of their pain. Herein, we review the literature on responsivity of individuals with CI to experimental pain stimuli. We discuss pain responding across a large number of neurological and neurodegenerative disorders in which CI is typically present. Overall, the existing data suggest that pain processing is altered in most individuals with CI compared with cognitively intact matched controls. The precise nature of these alterations varies with the type of CI (or associated clinical condition) and may also depend on the type of pain stimulation used and the type of pain responses assessed. Nevertheless, it is clear that regardless of the etiology of CI, patients do feel noxious stimuli, with more evidence for hypersensitivity than hyposensitivity to these stimuli compared with cognitively unimpaired individuals. Our current understanding of the neurobiological mechanisms underpinning these alterations is limited but may be enhanced through the use of animal models of CI, which also exhibit alterations in nociceptive responding. Further research using additional behavioural indices of pain is warranted. Increased understanding of altered experimental pain processing in CI will facilitate the development of improved diagnostic and therapeutic approaches for pain in individuals with CI.

  20. Boundary Conditions for 2D Boussinesq-type Wave-Current Interaction Equations

    Directory of Open Access Journals (Sweden)

    Mera M.

    2011-01-01

    Full Text Available This research focuses on the development of a set of two-dimensional boundary conditions for specific governing equations. The governing equations are existing Boussinesqtype equations which is capable of simulating wave-current interaction. The present boundary conditions consist of for waves only case and for currents only case. To simulate wave-current interaction, the two kinds of the present boundary conditions are then combined. A numerical model based on both the existing governing equations and the present boundary conditions is applied to simulation of currents only and of wave-current interaction propagating over a basin with a submerged shoal. The results of the numerical model show that the present boundary conditions go well with the existing Boussinesq-type wave-current interaction equations.

  1. Conventional housing conditions attenuate the development of experimental autoimmune encephalomyelitis.

    Directory of Open Access Journals (Sweden)

    Andreas Arndt

    Full Text Available BACKGROUND: The etiology of multiple sclerosis (MS has remained unclear, but a causative contribution of factors outside the central nervous system (CNS is conceivable. It was recently suggested that gut bacteria trigger the activation of CNS-reactive T cells and the development of demyelinative disease. METHODS: C57BL/6 (B6 mice were kept either under specific pathogen free or conventional housing conditions, immunized with the myelin basic protein (MBP-proteolipid protein (PLP fusion protein MP4 and the development of EAE was clinically monitored. The germinal center size of the Peyer's patches was determined by immunohistochemistry in addition to the level of total IgG secretion which was assessed by ELISPOT. ELISPOT assays were also used to measure MP4-specific T cell and B cell responses in the Peyer's patches and the spleen. Ear swelling assays were performed to determine the extent of delayed-type hypersensitivity reactions in specific pathogen free and conventionally housed mice. RESULTS: In B6 mice that were actively immunized with MP4 and kept under conventional housing conditions clinical disease was significantly attenuated compared to specific pathogen free mice. Conventionally housed mice displayed increased levels of IgG secretion in the Peyer's patches, while the germinal center formation in the gut and the MP4-specific TH17 response in the spleen were diminished after immunization. Accordingly, these mice displayed an attenuated delayed type hypersensitivity (DTH reaction in ear swelling assays. CONCLUSIONS: The data corroborate the notion that housing conditions play a substantial role in the induction of murine EAE and suggest that the presence of gut bacteria might be associated with a decreased immune response to antigens of lower affinity. This concept could be of importance for MS and calls for caution when considering the therapeutic approach to treat patients with antibiotics.

  2. Podocyte hypertrophy precedes apoptosis under experimental diabetic conditions.

    Science.gov (United States)

    Lee, Sun Ha; Moon, Sung Jin; Paeng, Jisun; Kang, Hye-Young; Nam, Bo Young; Kim, Seonghun; Kim, Chan Ho; Lee, Mi Jung; Oh, Hyung Jung; Park, Jung Tak; Han, Seung Hyeok; Yoo, Tae-Hyun; Kang, Shin-Wook

    2015-08-01

    Podocyte hypertrophy and apoptosis are two hallmarks of diabetic glomeruli, but the sequence in which these processes occur remains a matter of debate. Here we investigated the effects of inhibiting hypertrophy on apoptosis, and vice versa, in both podocytes and glomeruli, under diabetic conditions. Hypertrophy and apoptosis were inhibited using an epidermal growth factor receptor inhibitor (PKI 166) and a pan-caspase inhibitor (zAsp-DCB), respectively. We observed significant increases in the protein expression of p27, p21, phospho-eukaryotic elongation factor 4E-binding protein 1, and phospho-p70 S6 ribosomal protein kinase, in both cultured podocytes exposed to high-glucose (HG) medium, and streptozotocin-induced diabetes mellitus (DM) rat glomeruli. These increases were significantly inhibited by PKI 166, but not by zAsp-DCB. In addition, the amount of protein per cell, the relative cell size, and the glomerular volume were all significantly increased under diabetic conditions, and these changes were also blocked by treatment with PKI 166, but not zAsp-DCB. Increased protein expression of cleaved caspase-3 and cleaved poly (ADP-ribose) polymerase, together with increased Bax/Bcl-2 ratios, were also observed in HG-stimulated podocytes and DM glomeruli. Treatment with either zAsp-DCB or PKI 166 resulted in a significant attenuation of these effects. Both PKI 166 and zAsp-DCB also inhibited the increase in number of apoptotic cells, as assessed by Hoechst 33342 staining and TUNEL assay. Under diabetic conditions, inhibition of podocyte hypertrophy results in attenuated apoptosis, whereas blocking apoptosis has no effect on podocyte hypertrophy, suggesting that podocyte hypertrophy precedes apoptosis.

  3. Suitability of MEMS Accelerometers for Condition Monitoring: An experimental study.

    Science.gov (United States)

    Albarbar, Alhussein; Mekid, Samir; Starr, Andrew; Pietruszkiewicz, Robert

    2008-02-06

    With increasing demands for wireless sensing nodes for assets control and condition monitoring; needs for alternatives to expensive conventional accelerometers in vibration measurements have been arisen. Micro-Electro Mechanical Systems (MEMS) accelerometer is one of the available options. The performances of three of the MEMS accelerometers from different manufacturers are investigated in this paper and compared to a well calibrated commercial accelerometer used as a reference for MEMS sensors performance evaluation. Tests were performed on a real CNC machine in a typical industrial environmental workshop and the achieved results are presented.

  4. Inactivation of VHSV by infiltration and salt under experimental conditions

    DEFF Research Database (Denmark)

    Skall, Helle Frank; Jørgensen, Claus; Olesen, Niels Jørgen

    2014-01-01

    . In order to answer this question a small trial was set up. VHSV and NaCl was added to cell culture medium with 10% foetal bovine serum, in order to mimic a “dirty” environment, to obtain from 1.9% to 20.9% NaCl and kept in the dark at 4°C. Samples were titrated after 5 min, 1 h and 20 h. No reduction......At the moment the only legal method in Denmark to sanitize wastewater from fish cutting plants is by infiltration. To evaluate the inactivation effect of infiltration on VHSV an experimental examination was initiated. A column packed with gravel as top- and bottom layer (total of 22 cm) and a mid...... be a valuable method to sanitize VHSV infected water. Changes in temperature, pH, earth types in the area used for infiltration etc. may change the virus reduction, though. As some of the fish cutting plants are also smoking rainbow trout fillets, the question arose whether a brine solution will inactivate VHSV...

  5. Numerical and experimental study of the interaction between two marine current turbines

    CERN Document Server

    Mycek, Paul; Germain, Grégory; Pinon, Grégory; Rivoalen, Elie

    2013-01-01

    The understanding of interaction effects between marine energy converters represents the next step in the research process that should eventually lead to the deployment of such devices. Although some a priori considerations have been suggested recently, very few real condition studies have been carried out concerning this issue. Trials were run on 1/30th scale models of three-bladed marine current turbine prototypes in a flume tank. The present work focuses on the case where a turbine is placed at different locations in the wake of a first one. The interaction effects in terms of performance and wake of the second turbine are examined and compared to the results obtained on the case of one single turbine. Besides, a three-dimensional software, based on a vortex method is currently being developed, and will be used in the near future to model more complex layouts. The experimental study shows that the second turbine is deeply affected by the presence of an upstream device and that a compromise between individu...

  6. Experimental study on neptunium migration under in situ geochemical conditions

    Science.gov (United States)

    Kumata, M.; Vandergraaf, T. T.

    1998-12-01

    Results are reported for migration experiments performed with Np under in situ geochemical conditions over a range of groundwater flow rates in columns of crushed rock in a specially designed facility at the 240-level of the Underground Research Laboratory (URL) near Pinawa, Manitoba, Canada. This laboratory is situated in an intrusive granitic rock formation, the Lac du Bonnet batholith. Highly altered granitic rock and groundwater were obtained from a major subhorizontal fracture zone at a depth of 250 m in the URL. The granite was wet-crushed and wet-sieved with groundwater from this fracture zone. The 180-850-μm size fraction was selected and packed in 20-cm long, 2.54-cm in diameter Teflon™-lined stainless steel columns. Approximately 30-ml vols of groundwater containing 3HHO and 237Np were injected into the columns at flow rates of 0.3, 1, and 3 ml/h, followed by elution with groundwater, obtained from the subhorizontal fracture, at the same flow rates, for a period of 95 days. Elution profiles for 3HHO were obtained, but no 237Np was detected in the eluted groundwater. After terminating the migration experiments, the columns were frozen, the column material was removed and cut into twenty 1-cm thick sections and each section was analyzed by gamma spectrometry. Profiles of 237Np were obtained for the three columns. A one-dimensional transport model was fitted to the 3HHO breakthrough curves to obtain flow parameters for this experiment. These flow parameters were in turn applied to the 237Np concentration profiles in the columns to produce sorption and dispersion coefficients for Np. The results show a strong dependence of retardation factors ( Rf) on flow rate. The decrease in the retarded velocity of the neptunium ( Vn) varied over one order of magnitude under the geochemical conditions for these experiments.

  7. Growth of juvenile Arctica islandica under experimental conditions

    Science.gov (United States)

    Witbaard, R.; Franken, R.; Visser, B.

    1998-02-01

    In two laboratory experiments, the effects of temperature and food availability on the growth of 10- to 23-mm high specimens of the bivalve Arctica islandica were estimated. Each experimental set-up consisted of 5 treatments in which either the food supply or the temperature differed. It was demonstrated that Arctica is able to grow at temperatures as low as 1°C. A tenfold increase of shell growth was observed at temperatures between 1° and 12°C. The greatest change in growth rate took place between 1° and 6°C. Average instantaneous shell growth varies between 0.0003 at 1°C to 0.0032/day at 12°C. The results suggest that temperature hardly affects the time spent in filtration, whereas particle density strongly influences that response. Starved animals at 9°C have their siphons open during only 12% of the time, whereas the siphons of optimally fed animals were open on average during 76% of the observations. Increased siphon activity corresponded to high shell and tissue growth. At 9°C, average shell growth at the optimum cell density of 20×106 cell/l was 3.1 mm corresponding to an instantaneous rate of 0.0026/day. An algal cell density ( Isochrysis galbana, Dunaliella marina) ranging between 5 and 7×106 cell/l is just enough to keep shells alive at 9°C. Carbon conversion efficiency at 9°C is estimated to vary between 11 and 14%.

  8. Mitochondrial biogenesis of astrocytes is increased under experimental septic conditions

    Institute of Scientific and Technical Information of China (English)

    Wang Yang; Chen Zhijiang; Zhang Yu; Fang Suzhen; Zeng Qiyi

    2014-01-01

    Background Mitochondrial dysfunction has been reported to be one of the contributing factors of sepsis-associated encephalopathy (SAE).Mitochondrial biogenesis controls mitochondrial homeostasis and responds to changes in cellular energy demand.In addition,it is enhanced or decreased due to mitochondrial dysfunction during SAE.The aim of this study was to explore the changes of mitochondrial biogenesis of astrocytes under septic conditions.Methods Lipopolysaccharide (LPS; 50 ng/ml) and interferon-γ (IFN-γ; 200 U/ml) were incubated with astrocytes to model the effects of a septic insult on astrocytes in vitro.The mitochondrial ultrastructure and volume density were evaluated by transmission electron microscopy.Intracellular adenosine triphosphate (ATP) levels were detected by the firefly luciferase system.The expression of protein markers of mitochondrial biogenesis and the binding ability of mitochondrial transcription factor A (TFAM) were determined by western blot and electrophoretic mobility shift assays,respectively.The mitochondrial DNA (mtDNA) content was detected by real-time polymerase chain reaction.Results The number of mildly damaged mitochondria was found to be significantly greater after treatment for 6 hours,as compared with at 0 hour (P<0.05).The mitochondrial volume density was significantly elevated at 24 hours,as compared with at 0 hour (P<0.05).The ATP levels at 6 hours,12 hours,and 24 hours were significantly greater than those at 0 hour (P<0.05).The protein markers of mitochondrial biogenesis were significantly increased at 6 hours and 12 hours,as compared with at 0 hour (P<0.05).The TFAM binding activity was not significantly changed among the four time points analyzed.The mtDNA contents were significantly increased at 12 hours and 24 hours,as compared with at 0 hour (P<0.05).Conclusions Under septic conditions,mitochonddal biogenesis of astrocytes increased to meet the high-energy demand and to promote mitochondrial recovery

  9. Current transformers with nanocrystalline alloy toroidal core: analytical, computational and experimental studies

    Directory of Open Access Journals (Sweden)

    Benedito Antonio Luciano

    2012-10-01

    Full Text Available In this paper are presented theoretical analysis and experimental results concerning the performance of toroidal cores used in current transformers. For most problems concerning transformers design, analytical methods are useful, but numerical methods provide a better understanding of the transformers electromagnetic behaviour. Numerical field solutions may be used to determine the electrical equivalent circuit parameters of toroidal core current transformers. Since the exciting current of current transformers alters the ratio and phase angle of primary and secondary currents, it is made as small as possible though the use of high permeability and low loss magnetic material in the construction of the core. According to experimental results presented in this work, in comparison with others soft magnetic materials, nanocrystalline alloys appear as the best material to be used in toroidal core for current transformers.

  10. Experimental Evaluation of Grid Support Enabled PV Inverter Response to Abnormal Grid Conditions: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, Austin; Martin, Gregory; Hurtt, James

    2017-05-08

    As revised interconnection standards for grid-tied photovoltaic (PV) inverters address new advanced grid support functions (GSFs), there is increasing interest in inverter performance in the case of abnormal grid conditions. The growth of GSF-enabled inverters has outpaced the industry standards that define their operation, although recently published updates to UL1741 with Supplement SA define test conditions for GSFs such as volt-var control, frequency-watt control, and volt-age/frequency ride-through, among others. A comparative experimental evaluation has been completed on four commercially available, three-phase PV inverters in the 24.0-39.8 kVA power range on their GSF capability and the effect on abnormal grid condition response. This study examines the impact particular GSF implementations have on run-on times during islanding conditions, peak voltages in load rejection overvoltage scenarios, and peak currents during single-phase and three-phase fault events for individual inverters. This report reviews comparative test data, which shows that GSFs have little impact on the metrics of interest in most tests cases.

  11. Experimental study on rehydration conditions of freeze-dried platelets

    Institute of Scientific and Technical Information of China (English)

    Ju-li FAN; Xian-guo XU; Shao-zhi ZHANG; Fa-ming ZHU; Guang-ming CHEN; Li-xing YAN

    2009-01-01

    A rehydration process for freeze-dried human platelets was studied on 1 ml of samples.The effects of prehydration duration,prehydration temperature,an rehydration solution on the recovery rate,mean platelet volume(MPV),and platelet distribution width(PDW)were investigated.The mass changes during the prehydration process were also studied.Three prehydration durations:0,1.5,and 3.5 h,and two rehydration solutions:platelet-poor plasma and phosphate-buffered saline(PBS),were tested.It was found that:(1)the prehydration was of significance;(2)1.5 h of prehydration had better effects than 3.5 h of prehydration;(3)as a rehydration solution,the platelet-poor plasma behaved better than the PBS.The impacts of prehydration duration and temperature on the results were studied.There was almost no difference between 35 and 37℃.Among all the prehydration durations tested,15,30,60,90,and 120 min,the best result was achieved with the time duration of 15 min.The weights of prehydrated platelets at the end of each test were measured and the water contents were calculated.Atier 15 min of prehydration,the water contents in the samples were about(4.8±0.01)%and(5.27±0.29)%(w/w)corresponding to the conditions of 35 and 37 ℃.respectively.These results will be helpful for further studies on the freeze-drying of mammalian cells.

  12. Heterogeneous photocatalytic degradation of gallic acid under different experimental conditions.

    Science.gov (United States)

    Quici, Natalia; Litter, Marta I

    2009-07-01

    UV/TiO(2)-heterogeneous photocatalysis was tested as a process to degrade gallic acid (Gal) in oxygenated solutions at pH 3. In the absence of oxidants other than oxygen, decay followed a zero order rate at different concentrations and was slow at concentrations higher than 0.5 mM. Addition of Fe(3+), H(2)O(2) and the combination Fe(3+)/H(2)O(2) improved Gal degradation. In the absence of H(2)O(2), an optimal Fe : Gal molar ratio of 0.33 : 1 was found for the photocatalytic decay, beyond which addition of Fe(3+) was detrimental and even worse in comparison with the system in the absence of Fe(3+). TiO(2) addition was beneficial compared with the same system in the absence of the photocatalyst if Fe(3+) was added at low concentration (0.33 : 1 Fe : Gal molar ratio), while at high concentration (1 : 1 Fe : Gal molar ratio) TiO(2) did not exert any significant effect. H(2)O(2) addition (1 : 0.33 Gal : H(2)O(2) molar ratio, absence of Fe(iii)) also enhanced the heterogeneous photocatalytic reaction. Simultaneous addition of Fe(3+) and H(2)O(2) was more effective than the addition of the separate oxidants. This system was compared with Fenton and photo-Fenton systems. At low H(2)O(2) concentration (0.33 : 1 : 0.2 Fe : Gal : H(2)O(2) molar ratio), the presence of TiO(2) also enhanced the reaction. The influence of the thermal charge transfer reaction between Gal and Fe(iii), which leads to an important Gal depletion in the dark with formation of quinones, was analysed. The mechanisms taking place in these complex systems are proposed, paying particular attention to the important charge transfer reaction of the Fe(iii)-Gal complex operative in dark conditions.

  13. Flux quantum tunneling effect and its influence on the experimental critical current density

    Institute of Scientific and Technical Information of China (English)

    闻海虎; 赵忠贤; GriessenR.

    1995-01-01

    By using magnetic sweeping method, the temperature and magnetic field dependencies of the experimental current density and the normalized relaxation rate have been obtained. The true critical current density corresponding to the zero activation energy has been carried out based on the collective-pinning and the thermally-activated flux motion models, and therefore the influences of the quantum tunneling effect and the thermal activation effect on the experimental critical current density are distinguished. It is found that, with temperature lower than 10 K, the relaxation rate will not drop to zero when T approaches zero K because of the occurrence of the flux quantum tunneling. This additional flux motion further reduces the experimental critical current density j making it saturated with lowering temperature.

  14. Experimental study of yttrium barium copper oxide superconducting tape’s critical current under twisting moment

    Indian Academy of Sciences (India)

    Ziauddin Khan; Ananya Kundu; Subrata Pradhan

    2013-10-01

    Critical current (c) characteristics of 2G YBCO superconducting tape under the influence of twisting moment was experimentally investigated at varying current ramp rates in the self-field. Under a uniform twist, the degradation in the current-carrying capacity of YBCO tape up to 30% was observed at 77 K. The degradation is largely attributed to the shear stress and torsional shear strain resulting from the twisting. The superconductor to resistive transition index, , is also found to behave in an identical manner with increase in the twisting. Finite element analysis (FEA) of the tape in the experimental configuration with twisting moment being applied on to it has been carried out in COMSOL. The torsional strain calculated analytically as per the experimental configuration matches closely with that of FEA results, which shows that the critical current degradation is a function of strain.

  15. Mechanical, electrical and microstructural properties of cement-based materials in conditions of stray current flow

    NARCIS (Netherlands)

    Susanto, A.; Koleva, D.A.; Copuroglu, O.; Van Beek, C.; Van Breugel, K.

    2013-01-01

    This investigation presents a comparative study on mechanical properties, electrical resistivity and microstructure of mortar under DC current, compared to mortar in rest (no current) conditions. Monitoring was performed from 24h after casting until 84 days of cement hydration. A current

  16. Experimental investigation of the influence of electric field on frost layer growth under natural convection condition

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The influence of direct current (DC) electric field on the thickness and mass of frost on a cold vertical plate was investigated. The photos of frost layer growth were taken with and without the presence of electric field, and results showed that the electric field has a strong influence on the frost thickness. The influences of cold plate temperature and ambient temperature on frost thickness and frost mass were also investigated under the natural convection condition with electric field. Experimental results demonstrated that the cold plate temperature has very strong effect on the frost layer thickness, but its influence on frost mass is minor; the influence of ambient temperature on the frost mass is more obvious than that on the frost thickness.

  17. Stable overload conditions of high-temperature superconductors at alternating current injection

    Science.gov (United States)

    Romanovskii, V. R.

    2015-01-01

    The stability of alternating current injected into a high-temperature superconductor or into a current-carrying element on its basis is studied under weak cooling. The stability conditions of the current varying with time by a sinusoidal law are studied versus its frequency. It is shown that before unstable states set in, the peak values of the electric field intensity, current, and temperature in the superconductor are higher than the values determining a thermal electrodynamic stability boundary of the current permanently flowing through the superconductor—the so-called thermal quench current. It is found that ultimate stable alternating currents cause high stable thermal losses in superconductors; these losses being not considered in the modern theory of losses. Such stable conditions can be referred to as overload conditions. Analysis shows that there are characteristic times determining the time intervals within which alternating current is stable under overload conditions. Main thermoelectrodynamic mechanisms behind the existence of these intervals are formulated. They explain why the superconductor stable overheating and induced electric field reach high values before the injected alternating current becomes unstable. The existence of overload conditions considerably extends the application area of high-temperature superconductors.

  18. Automatic Condition Monitoring of Industrial Rolling-Element Bearings Using Motor’s Vibration and Current Analysis

    DEFF Research Database (Denmark)

    Yang, Zhenyu

    2015-01-01

    An automatic condition monitoring for a class of industrial rolling-element bearings is developed based on the vibration as well as stator current analysis. The considered fault scenarios include a single-point defect, multiple-point defects, and a type of distributed defect. Motivated...... is extensively studied under diverse operating conditions: different sensor locations, motor speeds, loading conditions, and data samples from different time segments. The experimental results showed the powerful capability of vibration analysis in the bearing point defect fault diagnosis. The current analysis...... by the potential commercialization, the developed system is promoted mainly using off-the-shelf techniques, that is, the high-frequency resonance technique with envelope detection and the average of short-time Fourier transform. In order to test the flexibility and robustness, the monitoring performance...

  19. Performance of current measurement system in poloidal field power supply for Experimental Advanced Superconducting Tokamak

    Science.gov (United States)

    Liu, D. M.; Li, J.; Wan, B. N.; Lu, Z.; Wang, L. S.; Jiang, L.; Lu, C. H.; Huang, J.

    2016-11-01

    As one of the core subsystems of the Experimental Advanced Superconducting Tokamak (EAST), the poloidal field power system supplies energy to EAST's superconducting coils. To measure the converter current in the poloidal field power system, a current measurement system has been designed. The proposed measurement system is composed of a Rogowski coil and a newly designed integrator. The results of the resistor-inductor-capacitor discharge test and the converter equal current test show that the current measurement system provides good reliability and stability, and the maximum error of the proposed system is less than 1%.

  20. Experimental identification of an azimuthal current in a magnetic nozzle of a radiofrequency plasma thruster

    Science.gov (United States)

    Takahashi, Kazunori; Chiba, Aiki; Komuro, Atsushi; Ando, Akira

    2016-10-01

    The azimuthal plasma current in a magnetic nozzle of a radiofrequency plasma thruster is experimentally identified by measuring the plasma-induced magnetic field. The axial plasma momentum increases over about 20 cm downstream of the thruster exit due to the Lorentz force arising from the azimuthal current. The measured current shows that the azimuthal current is given by the sum of the electron diamagnetic drift and \\mathbf{E}× \\mathbf{B} drift currents, where the latter component decreases with an increase in the magnetic field strength; hence the azimuthal current approaches the electron diamagnetic drift one for the strong magnetic field. The Lorentz force calculated from the measured azimuthal plasma current and the radial magnetic field is smaller than the directly measured force exerted to the magnetic field, which indicates the existence of a non-negligible Lorentz force in the source tube.

  1. Assessment of mycotoxin risk on corn in the Philippines under current and future climate change conditions.

    Science.gov (United States)

    Salvacion, Arnold R; Pangga, Ireneo B; Cumagun, Christian Joseph R

    2015-01-01

    This study attempts to assess the risk of mycotoxins (aflatoxins and fumonisins) contamination on corn in the Philippines under current and projected climate change conditions using fuzzy logic methodology based on the published range of temperature and rainfall conditions that favor mycotoxin development. Based on the analysis, projected climatic change will reduce the risk of aflatoxin contamination in the country due to increased rainfall. In the case of fumonisin contamination, most parts of the country are at a very high risk both under current conditions and the projected climate change conditions.

  2. Wave-current interactions in deep water conditions: field measurements and analyses

    Science.gov (United States)

    Rougier, Gilles; Rey, Vincent; Molcard, Anne

    2015-04-01

    The study of wave - current interaction has drawn interest in oceanography, ocean engineering, maritime navigation and for tides or waves power device design. In the context of the hydrodynamics study along the French Mediterranean coast, a current profiler was deployed near Toulon at the south of the "Port Cros" island. This coastal zone is characterized by a steep slope, the water depth varying from tens meters to several thousand meters over few kilometers from the coast. An ambient current, the "Northern Current", coming from the Ligurian sea (area of Genoa, Italy) and following the coast up to Toulon, is present all over the year. Its mean surface velocity is of about 0.30 m/s, its flow rate of about 1.5 Sv. The region is exposed to two dominating winds: the Mistral, coming from North-West, and Eastern winds. Both generate swell and/or wind waves in either following or opposing current conditions with respect to the Northern Current. A current profiler equipped with a wave tracking system (ACPD workhorse from RDI) was deployed from July to October 2014 in deep water conditions (depth of about 500m). The mooring system allowed the ADCP to measure the current profile from the sea surface down to 25m depth, which corresponds more or less to the depth of influence of waves of periods up to 10s. The collected data include energetic wave conditions in either following or opposing current conditions. The current intensity and its vertical profiles have shown a significant temporal variability according to the meteorological conditions. Effects of the wave conditions on the current properties are discussed. ACKNOWLEDGEMENTS This work was supported by the program BOMBYX and the ANR grant No ANR-13-ASTR-0007.

  3. Conditions for experimental Boson-sampling computer to disprove the Extended Church-Turing thesis

    CERN Document Server

    Shchesnovich, V S

    2014-01-01

    We consider the experimentally verifiable Extended Church-Turing thesis and derive sufficient conditions for an imperfect experimental realization of the Boson-sampling computer of Aaronson & Arkhipov to disprove it. Since the effect of the photon mode mismatch and the network imperfections (noise) are already known, we focus on the multi-photon and vacuum components of the input, the photons losses, and the detector dark counts. The main result is the complete set of sufficient conditions on the experimental imperfections for scalability of the experimental BS computer.

  4. Experimental study of swirl flow patterns in Gas Conditioning Tower at various entry conditions

    DEFF Research Database (Denmark)

    Jinov, Andrei A.; Larsen, Poul Scheel

    1999-01-01

    In a gas conditioning tower hot flue gas with relatively high dust loads is cooled by injecting water spray near the top. For satisfactory operation wet particles should be kept off walls and all water should have evaporated to yield a uniformly cooled flow before it reaches the bottom of the tower...

  5. How to determine a boundary condition for diffusion at a thin membrane from experimental data

    Science.gov (United States)

    Kosztołowicz, Tadeusz; WÄ sik, Sławomir; Lewandowska, Katarzyna D.

    2017-07-01

    We present a method of deriving a boundary condition for diffusion at a thin membrane from experimental data. Based on experimental results obtained for normal diffusion of ethanol in water, we show that the derived boundary condition at a membrane contains a term with a Riemann-Liouville fractional time derivative of order 1/2 . Such a form of the boundary condition shows that a transfer of particles through a thin membrane is a "long-memory process." The presented method is an example that an important part of the mathematical model of physical processes may be derived directly from experimental data.

  6. Magnetic Field Perturbations from Currents in the Dark Polar Regions During Quiet Geomagnetic Conditions

    DEFF Research Database (Denmark)

    Friis-Christensen, Eigil; Finlay, Chris; Hesse, M.

    2017-01-01

    In the day-side sunlit polar ionosphere the varying and IMF dependent convection creates strong ionospheric currents even during quiet geomagnetic conditions. Observations during such times are often excluded when using satellite data to model the internal geomagneticmain field. Observations from...... the night-side or local winter during quiet conditions are, however, also influenced by variations in the IMF. In this paper we briefly review the large scale features of the ionospheric currents in the polar regions with emphasis on the current distribution during undisturbed conditions. We examine....... The other category represent contributions caused by geomagnetic activity related to the substorm current wedge around local magnetic midnight. A new observation is a strong IMF By control of the residuals in the midnight sector indicating larger ionospheric currentsin the substorm current wedge...

  7. Changes in membrane currents during Pavlovian conditioning of single cortical neurons.

    Science.gov (United States)

    Woody, C D; Gruen, E; Birt, D

    1991-01-18

    Single electrode voltage clamp recordings were made during Pavlovian conditioning of single units of the motor cortex of cats. Units that developed a conditioned spike discharge in response to a click conditioned stimulus (CS) after pairing the click with glabella tap and local ionophoretic application of glutamate showed increases in input resistance and reductions of an early outward current induced by depolarizing commands and by return to holding potentials after hyperpolarizing commands. Changes in later currents were also found in some cells. Units that failed to develop a conditioned response did not show these changes. The decreases in membrane currents could contribute to an increased spike discharge in response to the CS as could the increased input resistance observed after conditioning. Conductance changes of this type may serve as engrams by which some forms of memory and learning are expressed across both vertebrate and invertebrate species.

  8. Reliable Selection and Holistic Stability Evaluation of Reference Genes for Rice Under 22 Different Experimental Conditions.

    Science.gov (United States)

    Wang, Zhaohai; Wang, Ya; Yang, Jing; Hu, Keke; An, Baoguang; Deng, Xiaolong; Li, Yangsheng

    2016-07-01

    Stable and uniform expression of reference genes across samples plays a key role in accurate normalization of gene expression by reverse-transcription quantitative polymerase chain reaction (RT-qPCR). For rice study, there is still a lack of validation and recommendation of appropriate reference genes with high stability depending on experimental conditions. Eleven candidate reference genes potentially owning high stability were evaluated by geNorm and NormFinder for their expression stability in 22 various experimental conditions. Best combinations of multiple reference genes were recommended depending on experimental conditions, and the holistic stability of reference genes was also evaluated. Reference genes would become more variable and thus needed to be critically selected in experimental groups of tissues, heat, 6-benzylamino purine, and drought, but they were comparatively stable under cold, wound, and ultraviolet-B stresses. Triosephosphate isomerase (TI), profilin-2 (Profilin-2), ubiquitin-conjugating enzyme E2 (UBC), endothelial differentiation factor (Edf), and ADP-ribosylation factor (ARF) were stable in most of our experimental conditions. No universal reference gene showed good stability in all experimental conditions. To get accurate expression result, suitable combination of multiple reference genes for a specific experimental condition would be a better choice. This study provided an application guideline to select stable reference genes for rice gene expression study.

  9. Robust Current Control of Doubly Fed Wind Turbine Generator under Unbalanced Grid Voltage Conditions

    DEFF Research Database (Denmark)

    Wang, Yun; Gong, Wenming; Wu, Qiuwei

    2014-01-01

    This paper presents the design of a H ∞ current controller for doubly fed induction generators (DFIGs) in order to maintain stable operation under unbalanced voltage conditions. The H ∞ current controller has a multi-input and multi-output (MIMO) structure and is designed using the loop shaping...... method. Case studies have been carried out in order to verify the efficacy of the proposed H ∞ current controller for DFIGs. The case study results show that the proposed H ∞ current controller can realize different control objectives, i.e. stable stator current, stable stator active power and stable...

  10. Correlates of experimentation with smoking and current cigarette consumption among adolescents

    Directory of Open Access Journals (Sweden)

    Amanda Gimenes Bonilha

    2014-12-01

    Full Text Available OBJECTIVE: The aim of this study was to analyze social characteristics and stress as correlates of cigarette smoking in adolescence. The main intent was to identify elements that distinguish adolescents who had experimented with smoking and did not progress to regular smoking from those who became current smokers. METHODS: Students at 10 high schools in the city of Ribeirão Preto, Brazil, completed a questionnaire based on an instrument employed in a similar large-scale study. The students were classified as never-smokers or experimenters. The experimenters were subcategorized as having become current smokers or nonprogressors. Analyses were performed using adjusted logistic models. RESULTS: A total of 2,014 students (mean age, 16.2 ± 1.1 years; females, 53% completed the questionnaire. We categorized 1,283 students (63.7% as never-smokers, 244 (12.1% as current smokers, and 487 (24.2% as nonprogressors. We found that experimentation with smoking was associated with being held back a grade in school (OR = 1.80, alcohol intake (low/occasional, OR = 8.92; high/regular, OR = 2.64, illicit drug use (OR = 9.32, having a sibling or cousin who smokes (OR = 1.39, having a friend who smokes (OR = 2.08, and high levels of stress (in females only, OR = 1.32. Factors associated with an increased risk of transitioning from experimenter to current smoker were alcohol intake (low/occasional, OR = 3.28; high/regular, OR = 2.16, illicit drug use (OR = 3.61, and having a friend who smokes (OR = 7.20. CONCLUSIONS: Current smoking was associated with a profile of socioeconomic correlates different from that associated with experimentation only. Our data (showing that current smoking was associated with having a friend who smokes, alcohol intake, and illicit drug use suggest the need for comprehensive approaches to discourage substance use during adolescence.

  11. Current Percolation in Medium with Boundaries under Quantum Hall Effect Conditions

    Directory of Open Access Journals (Sweden)

    M. U. Malakeeva

    2012-01-01

    Full Text Available The current percolation has been considered in the medium with boundaries under quantum Hall effect conditions. It has been shown that in that case the effective Hall conductivity has a nonzero value due to percolation of the Hall current through the finite number of singular points (in our model these are corners at the phase joints.

  12. AN EXPERIMENTAL AND NUMERICAL PREDICTION OF MARINE PROPELLER NOISE UNDER CAVITATING AND NON-CAVITATING CONDITIONS

    Directory of Open Access Journals (Sweden)

    Mohammad Reza Bagheri

    2015-06-01

    Full Text Available In this study, the hydrodynamics and noise prediction of a five blade marine propeller were analyzed through numerical and experimental methods under variety operational conditions. The hydrodynamics of the propeller was studied and the characteristic curves were presented in both numerical and experimental methods. Inception and development of sheet cavitation conditions are obtained in both numerical and experimental methods. The cavitation was started and developed by either increasing the propeller rotational speed in constant pressure or decreasing pressure, while the velocity was kept constant. Good agreements are observed between numerical and experimental results, qualitatively and quantitatively. The noise of the propeller was analyzed through Computational fluid dynamics (CFD method, based on the formulation of Ffowcs Williams and Hawkings (FW-H. Similarly, the experimental results collected from hydrophones were compared with numerical simulations. Finally, the effects of reflection in cavitation tunnel were obtained by considering overall sound pressure levels in numerical and experimental results.

  13. Experimental observations of stray current effects on steel fibres embedded in mortar

    DEFF Research Database (Denmark)

    Solgaard, A.O.S.; Carsana, M.; Geiker, M.R.;

    2013-01-01

    It is known that stray direct current can cause corrosive damage over time to bar reinforced concrete, but knowledge on the consequences to steel fibre reinforced concrete is limited. This paper presents analyses and corresponding results from an experimental program (parametric study) investigat...

  14. Experimental Results on Current-Driven Turbulence in Plasmas - a Survey

    NARCIS (Netherlands)

    Dekluiver, H.; Perepelkin, N. F.; Hirose, A.

    1991-01-01

    The experimental consequences of plasma turbulence driven by a current parallel to a magnetic field and concurrent anomalous plasma heating are reviewed, with an attempt to deduce universalities in key parameters such as the anomalous electrical conductivities observed in diverse devices. It has

  15. Reducing condition number by appropriate current decomposition on a multiplet of several wires

    CSIR Research Space (South Africa)

    Lysko, AA

    2011-07-01

    Full Text Available This paper discusses a numerical investigation in connection with the dependency of the condition number of the impedance matrix on the decomposition of current on a junction with several attached wires (multiplet). It is shown that the condition...

  16. Research on the induction motor current signature for centrifugal pump at cavitation condition

    Directory of Open Access Journals (Sweden)

    Yin Luo

    2015-11-01

    Full Text Available Cavitation is a major undesirable phenomenon for centrifugal pump because it can cause hydraulic performance deterioration, pump damage by pitting and material erosion, and structural vibration and noise. Cavitation can appear within the entire range of the operating conditions; therefore, it must be prevented by all means. Sensorless monitoring technology based on motor current signature analysis is non-intrusive and economic for monitoring motor-driven equipment. Thus, this technology is suitable for centrifugal pump systems. The motor current signature for centrifugal pump load at the cavitation condition is the basis of this technology. However, systematic research is lacking on sensorless monitoring technology based on motor current signature. As a result, the tentative exploration for motor current signature at cavitation load was conducted in this study. The results show that the stator current is still a sinusoidal alternating current strictly to the law of sine. Moreover, the root mean square of the current fluctuates because of different flow regimes in the cavitation progress and decreases because vapor density is smaller than water density when cavitation is fully formed. For the stator current spectrum, the noise level, noise distribution, rotation speed, and vane pass frequency components show features in the cavitation process. These indicator indexes change according to the stage of cavitation development. Thus, the motor current signature analysis is found to be a feasible and cost-effective method for the stages of cavitation condition.

  17. Electrodialytic removal of Cu, Zn, Pb, and Cd from harbor sediment: Influence of changing experimental conditions

    DEFF Research Database (Denmark)

    Nystrøm, Gunvor Marie; Ottosen, Lisbeth M.; Villumsen, Arne

    2005-01-01

    Electrodialytic remediation (EDR) was used to remove Cu, Zn, Pb, and Cd from contaminated harbor sediment. Extraction experiments were made prior to EDR, and the metal desorption was pH dependent but not liquid-to-solid ratio (L/S) dependent. The desorption order was Cd $GRT Zn $GRT Pb $GRT Cu...... for the removal of Cu, Zn, and Pb, probably due to oxidation of the sediments during stirring. Contrary, Cd removal was lower in the wet sediment as compared to the air-dried. The heavy metal removal was influenced by higher current strengths and varying L/S ratios. The highest removal obtained...... was in an experiment with dry sediment (L/S 8) and a 70 mA applied current that lasted 14 days. These experimental conditions were thereafter used to remediate more strongly contaminated sediments. Regardless of the initial heavy metal concentrations in the sediments, 67-87% Cu, 79-98% Cd, 90-97% Zn, and 91-96% Pb...

  18. Automatic Condition Monitoring of Industrial Rolling-Element Bearings Using Motor’s Vibration and Current Analysis

    Directory of Open Access Journals (Sweden)

    Zhenyu Yang

    2015-01-01

    Full Text Available An automatic condition monitoring for a class of industrial rolling-element bearings is developed based on the vibration as well as stator current analysis. The considered fault scenarios include a single-point defect, multiple-point defects, and a type of distributed defect. Motivated by the potential commercialization, the developed system is promoted mainly using off-the-shelf techniques, that is, the high-frequency resonance technique with envelope detection and the average of short-time Fourier transform. In order to test the flexibility and robustness, the monitoring performance is extensively studied under diverse operating conditions: different sensor locations, motor speeds, loading conditions, and data samples from different time segments. The experimental results showed the powerful capability of vibration analysis in the bearing point defect fault diagnosis. The current analysis also showed a moderate capability in diagnosis of point defect faults depending on the type of fault, severity of the fault, and the operational condition. The temporal feature indicated a feasibility to detect generalized roughness fault. The practical issues, such as deviations of predicted characteristic frequencies, sideband effects, time-average of spectra, and selection of fault index and thresholds, are also discussed. The experimental work shows a huge potential to use some simple methods for successful diagnosis of industrial bearing systems.

  19. SUSY effects in $R_b$: revisited under current experimental constraints

    CERN Document Server

    Su, Wei

    2016-01-01

    In this note we revisit the effects of natural SUSY in $R_b$ under current experimental constraints including the LHC Higgs data, the $B$-physics measurements, the dark matter relic density and direct detection limits, as well as the precision electroweak data. We first perform a scan to figure out the currently allowed parameter space of natural SUSY and then display the SUSY effects in $R_b$. We find that although the SUSY parameter space has been severely restrained by current experimental data, natural SUSY can still alter $R_b$ with a magnitude sizable enough to be observed at future $Z$-factories (ILC, CEPC, FCC-ee, Super $Z$-factory) which produce $10^9-10^{12}$ $Z$-bosons.

  20. First experimental results with the Current Limit Avoidance System at the JET tokamak

    Energy Technology Data Exchange (ETDEWEB)

    De Tommasi, G. [Associazione EURATOM-ENEA-CREATE, Università di Napoli Federico II, Via Claudio 21, 80125 Napoli (Italy); Galeani, S. [Dipartimento di Informatica, Sistemi e Produzione, Università di Roma, Tor Vergata, Rome (Italy); Jachmich, S. [Association EURATOM-Belgian State, Koninklijke Militaire School - Ecole Royale Militaire, B-1000 Brussels (Belgium); Joffrin, E. [IRFM-CEA, Centre de Cadarache, 13108 Saint-paul-lez-Durance (France); Lennholm, M. [EFDA Close Support Unit, Culham Science Centre, OX14 3DB Abingdon (United Kingdom); European Commission, B-1049 Brussels (Belgium); Lomas, P.J. [Euratom-CCFE, Culham Science Centre, OX14 3DB Abingdon (United Kingdom); Neto, A.C. [Associazione EURATOM-IST, Instituto de Plasmas e Fusao Nuclear, IST, 1049-001 Lisboa (Portugal); Maviglia, F. [Associazione EURATOM-ENEA-CREATE, Via Claudio 21, 80125 Napoli (Italy); McCullen, P. [Euratom-CCFE, Culham Science Centre, OX14 3DB Abingdon (United Kingdom); Pironti, A. [Associazione EURATOM-ENEA-CREATE, Università di Napoli Federico II, Via Claudio 21, 80125 Napoli (Italy); Rimini, F.G. [Euratom-CCFE, Culham Science Centre, OX14 3DB Abingdon (United Kingdom); Sips, A.C.C. [European Commission, B-1049 Brussels (Belgium); Varano, G.; Vitelli, R. [Dipartimento di Informatica, Sistemi e Produzione, Università di Roma, Tor Vergata, Rome (Italy); Zaccarian, L. [CNRS, LAAS, 7 Avenue du Colonel Roche, F-31400 Toulouse (France); Universitè de Toulouse, LAAS, F-31400 Toulouse (France)

    2013-06-15

    The Current Limit Avoidance System (CLA) has been recently deployed at the JET tokamak to avoid current saturations in the poloidal field (PF) coils when the eXtreme Shape Controller is used to control the plasma shape. In order to cope with the current saturation limits, the CLA exploits the redundancy of the PF coils system to automatically obtain almost the same plasma shape using a different combination of currents in the PF coils. In the presence of disturbances it tries to avoid the current saturations by relaxing the constraints on the plasma shape control. The CLA system has been successfully implemented on the JET tokamak and fully commissioned in 2011. This paper presents the first experimental results achieved in 2011–2012 during the restart and the ITER-like wall campaigns at JET.

  1. Experimentally determined mechanical properties of, and models for, the periodontal ligament: critical review of current literature.

    Science.gov (United States)

    Fill, Ted S; Carey, Jason P; Toogood, Roger W; Major, Paul W

    2011-01-01

    Introduction. This review is intended to highlight and discuss discrepancies in the literature of the periodontal ligament's (PDL) mechanical properties and the various experimental approaches used to measure them. Methods. Searches were performed on biomechanical and orthodontic publications (in databases: Compendex, EMBASE, MEDLINE, PubMed, ScienceDirect, and Scopus). Results. The review revealed that significant variations exist, some on the order of six orders of magnitude, in the PDL's elastic constants and mechanical properties. Possible explanations may be attributable to different experimental approaches and assumptions. Conclusions. The discrepancies highlight the need for further research into PDL properties under various clinical and experimental loading conditions. Better understanding of the PDL's biomechanical behavior under physiologic and traumatic loading conditions might enhance the understanding of the PDL's biologic reaction in health and disease. Providing a greater insight into the response of the PDL would be instrumental to orthodontists and engineers for designing more predictable, and therefore more efficacious, orthodontic appliances.

  2. THE MATHEMATIC MODEL OF POTENTIAL RELAXATION IN COULOSTATIC CONDITIONS FOR LIMITING DIFFUSION CURRENT CASE

    Directory of Open Access Journals (Sweden)

    O. H. Kapitonov

    2010-05-01

    Full Text Available A mathematical model of coulostatic relaxation of the potential for solid metallic electrode was presented. The solution in the case of limiting diffusion current was obtained. On the basis of this model the technique of concentration measurements for heavy metal ions in diluted solutions was suggested. The model adequacy was proved by experimental data.

  3. The effectiveness of experimental technology of attracting students to physical activity in improving orientation of physical condition

    Directory of Open Access Journals (Sweden)

    Yurchyshyn Y.V.

    2012-09-01

    Full Text Available The effectiveness of designed technologies to attract students during physical education to physical activity improving index is experimentally verified. 174 girls and 171 guys participated in this investigation. Found that the developed technology provides significantly better results than the traditional implementation of the contents of the current program in the following indicators: level of expression at the end of the semester and academic year (the current, final indexes of physical condition, theoretical preparedness in organization and implementation of physical activity improving orientation; number of indexes that in these periods improved, missed days due of sickness, condition, systematic and parameters of motor activity in the student's extracurricular time. These and source control implemented during a special sports and fitness west adversarial method, operational -- at each lesson for assessment of physical activity opportunities to current students.

  4. [Management in nursing in the current state impoverishment of working conditions].

    Science.gov (United States)

    Bellato, Roseney; Pereira, Wilza Rocha

    2004-01-01

    This study aims to provide reflection points on the nursing management process in the current state impoverishment financial conditions facing nursing work in a public health service in the State of Mato Grosso. We used the concepts of vulnerability, user rights and ethic to seek to understand how these concepts can broaden the view of citizenship in the search for better health care conditions for the users and workers in the institution studied. The blatant impoverishment of conditions that was detected point to the need for more awareness raising all levels where we think about, carry out and submit ourselves to the health care Nursing, working conditions, nursing ethics.

  5. EXPERIMENTAL INVESTIGATIONS ON DIFFUSION CHARACTERISTICS OF HIGH CONCENTRATION JETS IN ENVIRONMENTAL CURRENTS

    Institute of Scientific and Technical Information of China (English)

    张燕; 王道增; 樊靖郁

    2002-01-01

    By means of flow visualization and quantitative measurement, the diffusionpattern and concentration distribution characteristics of high concentration jets verticallydischarged into shallow moving waterbody were experimentally investigated in waterchannel. The interactions between the high concentration jets and environmental flowconditions were analysed, and the formulae of impinging point coordinate and transversespread angle are gained from data analysis. Experimental results indicate that the jets showcomplicated flow patterns and diffusion characteristics in near region, which are differentfrom common submerged jets, and spread downstream in the manner of density currents.

  6. Magnetic Field Perturbations from Currents in the Dark Polar Regions During Quiet Geomagnetic Conditions

    Science.gov (United States)

    Friis-Christensen, E.; Finlay, C. C.; Hesse, M.; Laundal, K. M.

    2017-02-01

    In the day-side sunlit polar ionosphere the varying and IMF dependent convection creates strong ionospheric currents even during quiet geomagnetic conditions. Observations during such times are often excluded when using satellite data to model the internal geomagnetic main field. Observations from the night-side or local winter during quiet conditions are, however, also influenced by variations in the IMF. In this paper we briefly review the large scale features of the ionospheric currents in the polar regions with emphasis on the current distribution during undisturbed conditions. We examine the distribution of scalar measurements of the magnetic field intensity minus predictions from a geomagnetic field model. These `residuals' fall into two main categories. One category is consistently distributed according to the well-known ionospheric plasma convection and its associated Birkeland currents. The other category represent contributions caused by geomagnetic activity related to the substorm current wedge around local magnetic midnight. A new observation is a strong IMF By control of the residuals in the midnight sector indicating larger ionospheric currents in the substorm current wedge in the northern polar region for By > 0 and correspondingly in the southern hemisphere for By < 0.

  7. Conditions for the validity of Faraday's law of induction and their experimental confirmation

    Energy Technology Data Exchange (ETDEWEB)

    Lopez-Ramos, A; Menendez, J R; Pique, C [Departamento de Fisica, Universidad de Oviedo, Escuela Politecnica Superior de Ingenieria de Gijon, Campus de Viesques, Edificio Este, 33203 Gijon (Spain)], E-mail: lramos@uniovi.es, E-mail: jrhevia@uniovi.es, E-mail: pique@uniovi.es

    2008-09-15

    This paper, as its main didactic objective, shows the conditions needed for the validity of Faraday's law of induction. Inadequate comprehension of these conditions has given rise to several paradoxes about the issue; some are analysed and solved in this paper in the light of the theoretical deduction of the induction law. Furthermore, an experimental set-up, in which such conditions are experimentally tested, is included. The experiment is not complicated and the method we use, and similar methods used elsewhere, is widely considered as suitable laboratory practice for students of first university courses in physics and engineering.

  8. Modelling of the reactive sputtering process with non-uniform discharge current density and different temperature conditions

    Science.gov (United States)

    Vašina, P; Hytková, T; Eliáš, M

    2009-05-01

    The majority of current models of the reactive magnetron sputtering assume a uniform shape of the discharge current density and the same temperature near the target and the substrate. However, in the real experimental set-up, the presence of the magnetic field causes high density plasma to form in front of the cathode in the shape of a toroid. Consequently, the discharge current density is laterally non-uniform. In addition to this, the heating of the background gas by sputtered particles, which is usually referred to as the gas rarefaction, plays an important role. This paper presents an extended model of the reactive magnetron sputtering that assumes the non-uniform discharge current density and which accommodates the gas rarefaction effect. It is devoted mainly to the study of the behaviour of the reactive sputtering rather that to the prediction of the coating properties. Outputs of this model are compared with those that assume uniform discharge current density and uniform temperature profile in the deposition chamber. Particular attention is paid to the modelling of the radial variation of the target composition near transitions from the metallic to the compound mode and vice versa. A study of the target utilization in the metallic and compound mode is performed for two different discharge current density profiles corresponding to typical two pole and multipole magnetics available on the market now. Different shapes of the discharge current density were tested. Finally, hysteresis curves are plotted for various temperature conditions in the reactor.

  9. Direct electric current treatment under physiologic saline conditions kills Staphylococcus epidermidis biofilms via electrolytic generation of hypochlorous acid.

    Directory of Open Access Journals (Sweden)

    Elizabeth L Sandvik

    Full Text Available The purpose of this study was to investigate the mechanism by which a direct electrical current reduced the viability of Staphylococcus epidermidis biofilms in conjunction with ciprofloxacin at physiologic saline conditions meant to approximate those in an infected artificial joint. Biofilms grown in CDC biofilm reactors were exposed to current for 24 hours in 1/10(th strength tryptic soy broth containing 9 g/L total NaCl. Dose-dependent log reductions up to 6.7 log(10 CFU/cm(2 were observed with the application of direct current at all four levels (0.7 to 1.8 mA/cm(2 both in the presence and absence of ciprofloxacin. There were no significant differences in log reductions for wells with ciprofloxacin compared to those without at the same current levels. When current exposures were repeated without biofilm or organics in the medium, significant generation of free chlorine was measured. Free chlorine doses equivalent to the 24 hour endpoint concentration for each current level were shown to mimic killing achieved by current application. Current exposure (1.8 mA/cm(2 in medium lacking chloride and amended with sulfate, nitrate, or phosphate as alternative electrolytes produced diminished kills of 3, 2, and 0 log reduction, respectively. Direct current also killed Pseudomonas aeruginosa biofilms when NaCl was present. Together these results indicate that electrolysis reactions generating hypochlorous acid from chloride are likely a main contributor to the efficacy of direct current application. A physiologically relevant NaCl concentration is thus a critical parameter in experimental design if direct current is to be investigated for in vivo medical applications.

  10. Direct electric current treatment under physiologic saline conditions kills Staphylococcus epidermidis biofilms via electrolytic generation of hypochlorous acid.

    Science.gov (United States)

    Sandvik, Elizabeth L; McLeod, Bruce R; Parker, Albert E; Stewart, Philip S

    2013-01-01

    The purpose of this study was to investigate the mechanism by which a direct electrical current reduced the viability of Staphylococcus epidermidis biofilms in conjunction with ciprofloxacin at physiologic saline conditions meant to approximate those in an infected artificial joint. Biofilms grown in CDC biofilm reactors were exposed to current for 24 hours in 1/10(th) strength tryptic soy broth containing 9 g/L total NaCl. Dose-dependent log reductions up to 6.7 log(10) CFU/cm(2) were observed with the application of direct current at all four levels (0.7 to 1.8 mA/cm(2)) both in the presence and absence of ciprofloxacin. There were no significant differences in log reductions for wells with ciprofloxacin compared to those without at the same current levels. When current exposures were repeated without biofilm or organics in the medium, significant generation of free chlorine was measured. Free chlorine doses equivalent to the 24 hour endpoint concentration for each current level were shown to mimic killing achieved by current application. Current exposure (1.8 mA/cm(2)) in medium lacking chloride and amended with sulfate, nitrate, or phosphate as alternative electrolytes produced diminished kills of 3, 2, and 0 log reduction, respectively. Direct current also killed Pseudomonas aeruginosa biofilms when NaCl was present. Together these results indicate that electrolysis reactions generating hypochlorous acid from chloride are likely a main contributor to the efficacy of direct current application. A physiologically relevant NaCl concentration is thus a critical parameter in experimental design if direct current is to be investigated for in vivo medical applications.

  11. Experimental Investigation of a Direct Methanol Fuel Cell with Hilbert Fractal Current Collectors

    Directory of Open Access Journals (Sweden)

    Jing-Yi Chang

    2014-01-01

    Full Text Available The Hilbert curve is a continuous type of fractal space-filling curve. This fractal curve visits every point in a square grid with a size of 2×2, 4×4, or any other power of two. This paper presents Hilbert fractal curve application to direct methanol fuel cell (DMFC current collectors. The current collectors are carved following first, second, and third order Hilbert fractal curves. These curves give the current collectors different free open ratios and opening perimeters. We conducted an experimental investigation into DMFC performance as a function of the free open ratio and opening perimeter on the bipolar plates. Nyquist plots of the bipolar plates are made and compared using electrochemical impedance spectroscopy (EIS experiments to understand the phenomena in depth. The results obtained in this paper could be a good reference for future current collector design.

  12. Experimental Research of Harmonic Spectrum of Currents at Traction Drive with PMSM

    Directory of Open Access Journals (Sweden)

    J. Novak

    2011-06-01

    Full Text Available The paper deals with the significant results of the experimental research of current harmonic spectrum of traction drive with permanent magnet synchronous motor. The experiments were done on a special workplace with a real traction drive for wheel vehicles. Current harmonic spectrum was analyzed by a specialized device on the base of central measuring station. The knowledge of current marked subharmonic components of stator winding is the most significant finding of experiments. The frequencies of these components are given by multiples of frequency of mechanical speeds. The subharmonic components also pass to input DC current of drive. This fact is important in particular from the point of view of legislative requirements to electromagnetic compatibility of drive with railway interlocking devices.

  13. Experimental study of a high-current FEM with a broadband microwave system

    Energy Technology Data Exchange (ETDEWEB)

    Denisov, G.G.; Bratman, V.L.; Ginzburg, N.S. [Institute of Applied Physics, Nizhny Novgorod (Russian Federation)] [and others

    1995-12-31

    One of the main features of FELs and FEMs is the possibility of fast and wideband tuning of the resonant frequency of active media, which can be provided by changing the particle energy. For a frequency adjustable FEM-oscillator, a broadband microwave system, which is simply combined with an electron-optical FEM system and consists of an oversized waveguide and reflectors based on the microwave beams multiplication effect has been proposed and studied successfully in {open_quotes}cold{close_quotes} measurements. Here, the operating ability of a cavity, that includes some key elements of the broadband microwave system, was tested in the presence of an electron beam. To provide large particle oscillation velocities in a moderate undulator field and the presence of a guide magnetic field, the FEM operating regime of double resonance was chosen. In this regime the cyclotron as well as undulator resonance conditions were satisfied. The FEM-oscillator was investigated experimentally on a high-current accelerator {open_quotes}Sinus-6{close_quotes} that forms an electron beam with particle energy 500keV and pulse duration 25ns. The aperture with a diameter 2.5mm at the center of the anode allows to pass through only the central fraction of the electron beam with a current about 100A and a small spread of longitudinal velocities of the particles. Operating transverse velocity was pumped into the electron beam in the pulse plane undulator of a 2.4cm period. The cavity with a frequency near 45GHz consists of a square waveguide and two reflectors. The broadband up-stream reflector based on the multiplication effect had the power reflectivity coefficient more than 90% in the frequency band 10% for the H{sup 10} wave of the square waveguide with the maximum about 100% at a frequency 45GHz. The down-stream narrow-band Bragg reflector had the power reflection coefficient approximately 80% in the frequency band of 4% near 45GHz for the operating mode.

  14. Evaluating the osseointegration of nanostructured titanium implants in animal models: Current experimental methods and perspectives (Review).

    Science.gov (United States)

    Babuska, Vaclav; Moztarzadeh, Omid; Kubikova, Tereza; Moztarzadeh, Amin; Hrusak, Daniel; Tonar, Zbynek

    2016-09-15

    The aim of this paper is to review the experimental methods currently being used to evaluate the osseointegration of nanostructured titanium implants using animal models. The material modifications are linked to the biocompatibility of various types of oral implants, such as laser-treated, acid-etched, plasma-coated, and sand-blasted surface modifications. The types of implants are reviewed according to their implantation site (endoosseous, subperiosteal, and transosseous implants). The animal species and target bones used in experimental implantology are carefully compared in terms of the ratio of compact to spongy bone. The surgical technique in animal experiments is briefly described, and all phases of the histological evaluation of osseointegration are described in detail, including harvesting tissue samples, processing undemineralized ground sections, and qualitative and quantitative histological assessment of the bone-implant interface. The results of histological staining methods used in implantology are illustrated and compared. A standardized and reproducible technique for stereological quantification of bone-implant contact is proposed and demonstrated. In conclusion, histological evaluation of the experimental osseointegration of dental implants requires careful selection of the experimental animals, bones, and implantation sites. It is also advisable to use larger animal models and older animals with a slower growth rate rather than small or growing experimental animals. Bones with a similar ratio of compact to spongy bone, such as the human maxilla and mandible, are preferred. A number of practical recommendations for the experimental procedures, harvesting of samples, tissue processing, and quantitative histological evaluations are provided.

  15. Experimental manifestation of the breakpoint region in the current-voltage characteristics of intrinsic Josephson junctions

    Science.gov (United States)

    Irie, A.; Shukrinov, Yu. M.; Oya, G.

    2008-10-01

    The experimental evidence of the breakpoint on the current-voltage characteristics (IVCs) of the stacks of intrinsic Josephson junctions (IJJs) is presented. The influence of the capacitive coupling on the IVCs of Bi2Sr2CaCu2Oy IJJs has been investigated. At 4.2K, clear breakpoint region is observed on the branches in the IVCs. It is found that due to the coupling between junctions, the hysteresis observed on the IVC is small compared to that expected from the McCumber parameter. Measurements agree well with the results predicted by the capacitively coupled Josephson junction model including the diffusion current.

  16. Current Control Method for Distributed Generation Power Generation Plants under Grid Fault Conditions

    DEFF Research Database (Denmark)

    Rodriguez, Pedro; Luna, Alvaro; Hermoso, Juan Ramon

    2011-01-01

    The operation of distributed power generation systems under grid fault conditions is a key issue for the massive integration of renewable energy systems. Several studies have been conducted to improve the response of such distributed generation systems under voltage dips. In spite of being less s...... the current ratings of the converter is introduced. Moreover, a novel flexible algorithm has been proposed in order to regulate easily the injection of positive and negative currents for general purpose applications....

  17. Magnetic signatures of ionospheric and magnetospheric current systems during geomagnetic quiet conditions - An overview

    DEFF Research Database (Denmark)

    Olsen, Nils; Stolle, Claudia

    2016-01-01

    High-precision magnetic measurements taken by LEO satellites (flying at altitudes between 300 and 800 km) allow for studying the ionosphericand magnetospheric processes and electric currents that causes only weak magnetic signature of a few nanotesla during geomagnetic quiet conditions....... Of particular importance for this endeavour are multipoint observationsin space, such as provided by the Swarm satellite constellation mission, inorder to better characterize the space-time-structure of the current systems. Focusing on geomagnetic quiet conditions, we provide an overview of ionospheric...... and magnetospheric sources and illustrate their magnetic signatureswith Swarm satellite observations....

  18. Presentation and comparison of experimental critical heat flux data at conditions prototypical of light water small modular reactors

    Energy Technology Data Exchange (ETDEWEB)

    Greenwood, M.S., E-mail: 1greenwoodms@ornl.gov; Duarte, J.P.; Corradini, M.

    2017-06-15

    Highlights: • Low mass flux and moderate to high pressure CHF experimental results are presented. • Facility uses chopped-cosine heater profile in a 2 × 2 square bundle geometry. • The EPRI, CISE-GE, and W-3 CHF correlations provide reasonable average CHF prediction. • Neural network analysis predicts experimental data and demonstrates utility of method. - Abstract: The critical heat flux (CHF) is a two-phase flow phenomenon which rapidly decreases the efficiency of the heat transfer performance at a heated surface. This phenomenon is one of the limiting criteria in the design and operation of light water reactors. Deviations of operating parameters greatly alters the CHF condition and must be experimentally determined for any new parameters such as those proposed in small modular reactors (SMR) (e.g. moderate to high pressure and low mass fluxes). Current open literature provides too little data for functional use at the proposed conditions of prototypical SMRs. This paper presents a brief summary of CHF data acquired from an experimental facility at the University of Wisconsin-Madison designed and built to study CHF at high pressure and low mass flux ranges in a 2 × 2 chopped cosine rod bundle prototypical of conceptual SMR designs. The experimental CHF test inlet conditions range from pressures of 8–16 MPa, mass fluxes of 500–1600 kg/m2 s, and inlet water subcooling from 250 to 650 kJ/kg. The experimental data is also compared against several accepted prediction methods whose application ranges are most similar to the test conditions.

  19. High performance predictive current control of a three phase VSI: An experimental assessment

    Indian Academy of Sciences (India)

    Vikas Kumar; Prerna Gaur; A P Mittal

    2014-12-01

    Delay has a significant role to play in the implementation of the predictive current control scheme as large amount of calculations are involved. Compensating delay in the predictive current controller design can lead to an improved load current total harmonic distortion (THD) and also an increased switching frequency. Minimization of switching frequency while maintaining the lower value of load current THD requires multiple objective optimization which is achieved by optimizing a single objective function, constructed using weighting factors as a linear combination of individual objective function. The effect of weighting factor on the switching frequency minimization and the current tracking error with delay compensation for the two level voltage source inverter (VSI) are investigated in this paper. The outcomes of the predictive current control using an optimized weighting factor which is calculated using branch and bound algorithm with the delay compensation are compared with the PWM based current control scheme. The experimental tests are conducted on a 2.2 kW VSI to verify the simulation observations.

  20. Enhanced Decoupled Double Synchronous Reference Frame Current Controller for Unbalanced Grid-Voltage Conditions

    DEFF Research Database (Denmark)

    Reyes, M.; Rodriguez, Pedro; Vazquez, S.;

    2012-01-01

    . In these codes, the injection of positive- and negative-sequence current components becomes necessary for fulfilling, among others, the low-voltage ride-through requirements during balanced and unbalanced grid faults. However, the performance of classical dq current controllers, applied to power converters......, under unbalanced grid-voltage conditions is highly deficient, due to the unavoidable appearance of current oscillations. This paper analyzes the performance of the double synchronous reference frame controller and improves its structure by adding a decoupling network for estimating and compensating...

  1. Jump Conditions of a Shock with Current in Cylindrical Non-Neutral Plasma

    Institute of Scientific and Technical Information of China (English)

    HE Yong; HU Xi-Wei; HU Ye-Min

    2006-01-01

    Jump conditions of the parameters (mass flow, momentum flow and energy Bow) of a shock with current (thereby, electric and magnetic field) in cylindrical non-neutral plasma are presented and derived from Maxwell's equations and two fluid equations for electron and ion fluid. The critical Mach number for the shock existence is calculated, which depends on the shock carried current, the ion charge, and the composition of the magnetic and thermal pressure. The numerical results show that both the strength and profiles of the downstream shock parameters will be affected obviously by the shock carried current, electric and magnetic field in the two-dimensional shock.

  2. Experimental study on the effect of surface conditions on evaporation of sprayed liquid droplet

    Energy Technology Data Exchange (ETDEWEB)

    El-Sayed R, Negeed [Reactors Department, Nuclear Research Center, Atomic Energy Authority, Cairo (Egypt); El-Sayed R, Negeed; Ishihara, N.; Tagashira, K.; Hidaka, S.; Kohno, M.; Takata, Y. [Department of Mechanical Engineering Science, Faculty of Engineering, Kyushu University, Fukuoka (Japan)

    2010-12-15

    The present study investigates experimentally the effects of thermal properties of the hot surface and droplet characteristics on the droplet evaporation. Cylindrical blocks made of Stainless Steel, Aluminum and Brass with different degrees of surface roughness were used. The droplet diameter and velocity were controlled independently. The behavior of droplet during the collision with hot surface was observed with a high-speed camera. The results presented the effect of the thermal properties of the hot surface, droplet Weber number, droplet velocity, droplet size, hot surface conditions; surface superheat and degree of surface roughness on the solid-liquid contact time and the maximum spread of droplet over the surface. Empirical correlations have been deduced describing the relationship between the hydrodynamic characteristics of an individual droplet impinging on a heated surface and concealing the affecting parameters in such process. Also, the comparison between the current results and the results due to others investigators shows good agreement in which the difference between them ranged from 5% to 25%. (authors)

  3. Computational and experimental studies of laser cutting of the current collectors for lithium-ion batteries

    Science.gov (United States)

    Lee, Dongkyoung; Patwa, Rahul; Herfurth, Hans; Mazumder, Jyotirmoy

    2012-07-01

    Sizing electrodes is an important step during Lithium-ion battery manufacturing processes since poor cut edge affects battery performance significantly and sometime leads to fire hazard. Mechanical cutting could result in a poor cut quality with defects. The cutting quality can be improved by using a laser, due to its high energy concentration, fast processing time, small heat-affected zone, and high precision. The cutting quality is highly influenced by operating parameters such as laser power and scanning speed. Thus, we studied a numerical simulation to provide a guideline for achieving clear edge quality. In order to simulate electrodes laser cutting for Lithium-Ion batteries, understanding the behavior of current collectors is crucial. This study focuses on current collectors, such as pure copper and aluminium. Numerical studies utilized a 3D self-consistent mathematical model for laser-material interaction. Observations of penetration time, depth, and threshold during laser cutting processes of current collectors are described. The model is validated experimentally by cutting current collectors and single side-coated electrodes with a single mode fiber laser. The copper laser cutting is laser intensity and interaction time dependent process. The aluminium laser cutting depends more on laser intensity than the interaction time. Numerical and experimental results show good agreement.

  4. Complementary numerical–experimental benchmarking for shape optimization and validation of structures subjected to wave and current forces

    DEFF Research Database (Denmark)

    Markus, D.; Ferri, Francesco; Wüchner, R.

    2015-01-01

    that focuses on differences in load curves resulting from 2D and 3D flows. It is shown that the major trends predicted by the numerical simulations are also captured in the experiment, highlighting the potential of CFD as a powerful tool for shape optimization studies. The overall aim of the paper...... variations of the structure on the resulting horizontal forces. Steady current conditions, dynamic loading due to waves, and combined wave–current scenarios are considered. A clear focus is put on simplicity and reproducibility, allowing for efficient testing of related methods and codes. This is achieved...... by defining a simple test geometry, altered in one design variable only, and by designing the test case such that a two dimensional analysis of the flow fields is possible. The force sensitivities to changes in the geometry are determined both numerically and experimentally for a great bandwidth of different...

  5. Optimization of experimental conditions of hot wire method in thermal conductivity measurements

    OpenAIRE

    Ma, Luyao

    2012-01-01

    This work studied the hot wire method in measuring thermal conductivity at room temperature. The purpose is to find the optimized experimental conditions to minimize natural convection in liquid for this method, which will be taken as reference for high temperature thermal conductivity measurement of slag. Combining room temperature experiments and simulation with COMSOL Multiphysics 4.2a, the study on different experimental parameters which may influence the accuracy of the measured thermal ...

  6. Principle and experimental investigation of current-driven negative-inductance superconducting quantum interference device

    Science.gov (United States)

    Li, Hao; Liu, Jianshe; Zhang, Yingshan; Cai, Han; Li, Gang; Liu, Qichun; Han, Siyuan; Chen, Wei

    2017-03-01

    A negative-inductance superconducting quantum interference device (nSQUID) is an adiabatic superconducting logic device with high energy efficiency, and therefore a promising building block for large-scale low-power superconducting computing. However, the principle of the nSQUID is not that straightforward and an nSQUID driven by voltage is vulnerable to common mode noise. We investigate a single nSQUID driven by current instead of voltage, and clarify the principle of the adiabatic transition of the current-driven nSQUID between different states. The basic logic operations of the current-driven nSQUID with proper parameters are simulated by WRspice. The corresponding circuit is fabricated with a 100 A cm‑2 Nb-based lift-off process, and the experimental results at low temperature confirm the basic logic operations as a gated buffer.

  7. TRENDS AND STRUCTURAL CHANGES ON THE GAS MARKET UNDER CURRENT CONDITIONS

    Directory of Open Access Journals (Sweden)

    Andrei E. Shmagin

    2013-01-01

    Full Text Available The popularity of natural gas as an energy source increasingly grows. The rate of demand growth and the gas market development depend on a variety of key conditions discussed in the paper. The current market situation and trends are analyzed in the context of the global balance of energy.

  8. TRENDS AND STRUCTURAL CHANGES ON THE GAS MARKET UNDER CURRENT CONDITIONS

    OpenAIRE

    Andrei E. Shmagin

    2013-01-01

    The popularity of natural gas as an energy source increasingly grows. The rate of demand growth and the gas market development depend on a variety of key conditions discussed in the paper. The current market situation and trends are analyzed in the context of the global balance of energy.

  9. Assessing Lebanon's wildfire potential in association with current and future climatic conditions

    Science.gov (United States)

    George H. Mitri; Mireille G. Jazi; David McWethy

    2015-01-01

    The increasing occurrence and extent of large-scale wildfires in the Mediterranean have been linked to extended periods of warm and dry weather. We set out to assess Lebanon's wildfire potential in association with current and future climatic conditions. The Keetch-Byram Drought Index (KBDI) was the primary climate variable used in our evaluation of climate/fire...

  10. Contemporary art and its commercial markets: a report on current conditions and future scenarios

    NARCIS (Netherlands)

    Lind, M.; Velthuis, O.

    2012-01-01

    Contemporary Art and Its Commercial Markets: A Report on Current Conditions and Future Scenarios maps and analyzes the complex and contested entanglements of contemporary art and its commercial markets. Contemporary art as an asset category and celebrity accessory, the rise of the art fair, and the

  11. Contemporary art and its commercial markets: a report on current conditions and future scenarios

    NARCIS (Netherlands)

    Lind, M.; Velthuis, O.

    2012-01-01

    Contemporary Art and Its Commercial Markets: A Report on Current Conditions and Future Scenarios maps and analyzes the complex and contested entanglements of contemporary art and its commercial markets. Contemporary art as an asset category and celebrity accessory, the rise of the art fair, and the

  12. Evaluation of new reference genes in papaya for accurate transcript normalization under different experimental conditions.

    Science.gov (United States)

    Zhu, Xiaoyang; Li, Xueping; Chen, Weixin; Chen, Jianye; Lu, Wangjin; Chen, Lei; Fu, Danwen

    2012-01-01

    Real-time reverse transcription PCR (RT-qPCR) is a preferred method for rapid and accurate quantification of gene expression studies. Appropriate application of RT-qPCR requires accurate normalization though the use of reference genes. As no single reference gene is universally suitable for all experiments, thus reference gene(s) validation under different experimental conditions is crucial for RT-qPCR analysis. To date, only a few studies on reference genes have been done in other plants but none in papaya. In the present work, we selected 21 candidate reference genes, and evaluated their expression stability in 246 papaya fruit samples using three algorithms, geNorm, NormFinder and RefFinder. The samples consisted of 13 sets collected under different experimental conditions, including various tissues, different storage temperatures, different cultivars, developmental stages, postharvest ripening, modified atmosphere packaging, 1-methylcyclopropene (1-MCP) treatment, hot water treatment, biotic stress and hormone treatment. Our results demonstrated that expression stability varied greatly between reference genes and that different suitable reference gene(s) or combination of reference genes for normalization should be validated according to the experimental conditions. In general, the internal reference genes EIF (Eukaryotic initiation factor 4A), TBP1 (TATA binding protein 1) and TBP2 (TATA binding protein 2) genes had a good performance under most experimental conditions, whereas the most widely present used reference genes, ACTIN (Actin 2), 18S rRNA (18S ribosomal RNA) and GAPDH (Glyceraldehyde-3-phosphate dehydrogenase) were not suitable in many experimental conditions. In addition, two commonly used programs, geNorm and Normfinder, were proved sufficient for the validation. This work provides the first systematic analysis for the selection of superior reference genes for accurate transcript normalization in papaya under different experimental conditions.

  13. Evaluation of new reference genes in papaya for accurate transcript normalization under different experimental conditions.

    Directory of Open Access Journals (Sweden)

    Xiaoyang Zhu

    Full Text Available Real-time reverse transcription PCR (RT-qPCR is a preferred method for rapid and accurate quantification of gene expression studies. Appropriate application of RT-qPCR requires accurate normalization though the use of reference genes. As no single reference gene is universally suitable for all experiments, thus reference gene(s validation under different experimental conditions is crucial for RT-qPCR analysis. To date, only a few studies on reference genes have been done in other plants but none in papaya. In the present work, we selected 21 candidate reference genes, and evaluated their expression stability in 246 papaya fruit samples using three algorithms, geNorm, NormFinder and RefFinder. The samples consisted of 13 sets collected under different experimental conditions, including various tissues, different storage temperatures, different cultivars, developmental stages, postharvest ripening, modified atmosphere packaging, 1-methylcyclopropene (1-MCP treatment, hot water treatment, biotic stress and hormone treatment. Our results demonstrated that expression stability varied greatly between reference genes and that different suitable reference gene(s or combination of reference genes for normalization should be validated according to the experimental conditions. In general, the internal reference genes EIF (Eukaryotic initiation factor 4A, TBP1 (TATA binding protein 1 and TBP2 (TATA binding protein 2 genes had a good performance under most experimental conditions, whereas the most widely present used reference genes, ACTIN (Actin 2, 18S rRNA (18S ribosomal RNA and GAPDH (Glyceraldehyde-3-phosphate dehydrogenase were not suitable in many experimental conditions. In addition, two commonly used programs, geNorm and Normfinder, were proved sufficient for the validation. This work provides the first systematic analysis for the selection of superior reference genes for accurate transcript normalization in papaya under different experimental

  14. Experimental study of the velocity of density currents in convergent and divergent channels

    Institute of Scientific and Technical Information of China (English)

    Hasan Torabi POUDEH; Samad EMAMGHOLIZADEH; Manoocher Fathi-MOGHADAM

    2014-01-01

    The head velocity of the density current in the convergent and divergent channel is a key parameter for evaluating the extent to which suspended material travels, and for determining the type and distribution of sediment in the water body. This study experimentally evaluated the effects of the reach degree of convergence and divergence on the head velocity of the density current. Experiments were conducted in the flume with 6.0 m long, 0.72 m width and 0.6 m height. The head velocity was measured at three convergent degrees (-8o;-12o;-26o), at three divergent degrees (8o; 12o; 26o) and two slopes (0.009, 0.016) for various discharges. The measured head velocity of the density current is compared with the head velocity of the density current in the constant cross section channel. Based on non-dimensional and statistical analysis, relations as linear multiple regression are offered for predicting head velocity of the density current in the convergent, divergent and constant cross section channel. Also the results of this research show that for the same slope and discharge, the head velocity of the density current in the convergent and divergent channel are greater and less than the head velocity of the constant cross section, respectively.

  15. Cerebral: visualizing multiple experimental conditions on a graph with biological context.

    Science.gov (United States)

    Barsky, Aaron; Munzner, Tamara; Gardy, Jennifer; Kincaid, Robert

    2008-01-01

    Systems biologists use interaction graphs to model the behavior of biological systems at the molecular level. In an iterative process, such biologists observe the reactions of living cells under various experimental conditions, view the results in the context of the interaction graph, and then propose changes to the graph model. These graphs ser ve as a form of dynamic knowledge representation of the biological system being studied and evolve as new insight is gained from the experimental data. While numerous graph layout and drawing packages are available, these tools did not fully meet the needs of our immunologist collaborators. In this paper, we describe the data information display needs of these immunologists and translate them into design decisions. These decisions led us to create Cerebral, a system that uses a biologically guided graph layout and incorporates experimental data directly into the graph display. Small multiple views of different experimental conditions and a data-driven parallel coordinates view enable correlations between experimental conditions to be analyzed at the same time that the data is viewed in the graph context. This combination of coordinated views allows the biologist to view the data from many different perspectives simultaneously. To illustrate the typical analysis tasks performed, we analyze two datasets using Cerebral. Based on feedback from our collaborators we conclude that Cerebral is a valuable tool for analyzing experimental data in the context of an interaction graph model.

  16. Conditional Short-crested second order waves in shallow water and with superimposed current

    DEFF Research Database (Denmark)

    Jensen, Jørgen Juncher

    2004-01-01

    For bottom-supported offshore structures like oil drilling rigs and oil production platforms, a deterministic design wave approach is often applied using a regular non-linear Stokes' wave. Thereby, the procedure accounts for non-linear effects in the wave loading but the randomness of the ocean...... wave, given the value of the wave crest at a specific point in time or space. In the present paper a derivation of the expected second order short-crested wave riding on a uniform current is given. The analysis is based on the second order Sharma and Dean shallow water wave theory and the direction...... of the main wind direction can make any direction with the current. Numerical results showing the importance of the water depth, the directional spreading and the current on the conditional mean wave profile and the associated wave kinematics are presented. A discussion of the use of the conditional wave...

  17. Experimental study on bed-load sediment transport under irregular wave and current combined flow

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Using an irregularly oscillating tray and flume, a series of experiments are completed to evaluate bed-load sediment transport rate under irregular wave- current coexistent fild. Testing conditions include three interaction angles 0°, 45°, 90° and two kinds of median sizes (0.38 and 1.10 mm).The results of transport rate show that the net sediment transport rate can be expressed approximately as the function of the maximum bottom shear stress of waves, mean shear stress of current and the grain size.

  18. Experimental and theoretical analysis of an optical current sensor for high power systems

    Science.gov (United States)

    Brigida, A. C. S.; Nascimento, I. M.; Mendonça, S.; Costa, J. C. W. A.; Martinez, M. A. G.; Baptista, J. M.; Jorge, P. A. S.

    2013-03-01

    A magneto-optical sensor, using a dual quadrature polarimetric processing scheme, was evaluated for current metering and protection applications in high voltage lines. Sensor calibration and resolution were obtained in different operational conditions using illumination in the 1550-nm band. Results obtained indicated the feasibility of interrogating such sensor via the optical ground wire (OPGW) link installed in standard high power grids. The polarimetric bulk optical current sensor also was theoretically studied, and the effects of different sources of error considering practical deployment were evaluated. In particular, the interference from external magnetic fields in a tree-phase system was analyzed.

  19. Conditional short-crested waves in shallow water and with superimposed current

    DEFF Research Database (Denmark)

    Jensen, Jørgen Juncher

    2002-01-01

    For bottom-supported offshore structures like oil drilling rigs and oil production platforms, a deterministic design wave approach is often applied using a regular non-linear Stokes´ wave. Thereby, the procedure accounts for non-linear effects in the wave loading but the randomness of the ocean...... wave, given the value of the wave crest at a specific point in time or space. In the present paper a derivation of the expected linear short-crested wave riding on a uniform current is given. The analysis is based on the conventional shallow water Airy wave theory and the direction of the main wind...... direction can make any direction with the current. A consistent derivation of the wave spectrum taking into account current and finite water depth is used. The numerical results show a significant effect of the water depth, the directional spreading and the current on the conditional mean wave profile...

  20. Numerical simulation and experimental validation of a direct current air corona discharge under atmospheric pressure

    Institute of Scientific and Technical Information of China (English)

    Liu Xing-Hua; He Wei; Yang Fan; Wang Hong-Yu; Liao Rui-Jin; Xiao Han-Guang

    2012-01-01

    Air corona discharge is one of the critical problems associated with high-voltage equipment.Investigating the corona mechanism plays a key role in enhancing the electrical insulation performance.An improved self-consistent multi-component two-dimensional plasma hybrid model is presented for the simulation of a direct current atmospheric pressure corona discharge in air.The model is based on plasma hydrodynamic and chemical models,and includes 12 species and 26 reactions.In addition,the photoionization effect is introduced into the model.The simulation on a bar-plate electrode configuration with an inter-electrode gap of 5.0 mm is carried out.The discharge voltage-current characteristics and the current density distribution predicted by the hybrid model agree with the experimental measurements.In addition,the dynamics of volume charged species generation,discharge current waveform,current density distribution at an electrode,charge density,electron temperature,and electric field variations are investigated in detail based on the model.The results indicate that the model can contribute valuable insights into the physics of an air plasma discharge.

  1. Microscopic Structure of Shocks and Antishocks in the ASEP Conditioned on Low Current

    Science.gov (United States)

    Belitsky, V.; Schütz, G. M.

    2013-07-01

    We study the time evolution of the ASEP on a one-dimensional torus with L sites, conditioned on an atypically low current up to a finite time t. For a certain one-parameter family of initial measures with a shock we prove that the shock position performs a biased random walk on the torus and that the measure seen from the shock position remains invariant. We compute explicitly the transition rates of the random walk. For the large scale behavior this result suggests that there is an atypically low current such that the optimal density profile that realizes this current is a hyperbolic tangent with a traveling shock discontinuity. For an atypically low local current across a single bond of the torus we prove that a product measure with a shock at an arbitrary position and an antishock at the conditioned bond remains a convex combination of such measures at all times which implies that the antishock remains microscopically stable under the locally conditioned dynamics. We compute the coefficients of the convex combinations.

  2. Experimental investigation on steam condensation in the presence of air and helium: forced convection conditions

    Energy Technology Data Exchange (ETDEWEB)

    Bucci, M., E-mail: matteo.bucci@cea.fr [Univ. of Pisa, DIMNP, Pisa (Italy); CEA Saclay, CEA/DEN/DANS/DM2S/SFME/LETR (France); Ambrosini, W.; Forgione, N. [Univ. of Pisa, DIMNP, Pisa (Italy); Lioce, D [Univ. of Pisa, DIMNP, Pisa (Italy); Westinghouse Electric Belguim, Nivelles (Belgium)

    2011-07-01

    This paper discusses the results obtained from recent experimental investigations devoted to the study of steam condensation in the presence of air and a light noncondensable gas. The experiments are intended to provide data for the validation of engineering models and CFD codes. The original experimental data herein discussed focus on forced convection turbulent boundary layer conditions and involve atmospheric pressure, different conditions for mixture velocity (from 1.5 to 3.5 m/s), mixture composition (form 0 to 75 per cent of the light species in the overall amount of noncondensable gases) and two nominal electrical power supply of the steam generator. The experimental data are qualified against correlations based on the heat and mass transfer analogy and to the predictions obtained by an in house condensation model implemented in a commercial CFD code. (author)

  3. Uncertain boundary condition Bayesian identification from experimental data: A case study on a cantilever beam

    Science.gov (United States)

    Ritto, T. G.; Sampaio, R.; Aguiar, R. R.

    2016-02-01

    In many mechanical applications (wind turbine tower, substructure joints, etc.), the stiffness of the boundary conditions is uncertain and might decrease with time, due to wear and/or looseness. In this paper, a torsional stiffness parameter is used to model the clamped side of a Timoshenko beam. The goal is to perform the identification with experimental data. To represent the decreasing stiffness of the clamped side, an experimental test rig is constructed, where several rubber layers are added to the clamped side, making it softer. Increasing the number of layers decreases the stiffness, thus representing a loss in the stiffness. The Bayesian approach is applied to update the probabilistic model related to the boundary condition (torsional stiffness parameter). The proposed Bayesian strategy worked well for the problem analyzed, where the experimental natural frequencies were within the 95% confidence limits of the computed natural frequencies probability density functions.

  4. Experimental manifestation of the breakpoint region in the current-voltage characteristics of intrinsic Josephson junctions

    OpenAIRE

    Irie, A.; Shukrinov, Yu M.; Oya, G.

    2008-01-01

    The experimental evidence of the breakpoint on the current-voltage characteristics (IVCs) of the stacks of intrinsic Josephson junctions (IJJs) is presented. The influence of the capacitive coupling on the IVCs of Bi$_2$Sr$_2$CaCu$_2$O$_y$ IJJs has been investigated. At 4.2 K, clear breakpoint region is observed on the branches in the IVCs. It is found that the hysteresis observed on the IVC is suppressed due to the coupling compared with that expected from the McCumber parameter. Measurement...

  5. Jump Conditions of a Non-Neutral Plasma Shock with Current and Potential Difference

    Institute of Scientific and Technical Information of China (English)

    胡希伟

    2002-01-01

    Jump conditions about the total momentum flux and energy flux in a non-neutral plasma shock with electric current and field are given, which are derived from the double fluid equations and the Poisson equation for electron and ion fluids. Furthermore, we derive the relations between the upstream and downstream velocities and temperatures, and the minimum upstream Mach number for the plasma shock existence M1min, which depend on the current through the shock front J0, the electric potential difference between the upstream and downstream of shock △φ, and the ion charge Z.

  6. EXPERIMENTAL STUDY OF EFFECTS OF OPERATING CONDITIONS ON THE FLOW CHARACTERISTICS OF WATER HYDRAULIC THROTTLE

    Institute of Scientific and Technical Information of China (English)

    Liu Yinshui; Nie Songlin; Zhu Yuquan; He Xiaofeng; Li Zhuangyun

    2004-01-01

    Experimental investigations are made on the effects of operating conditions on the flow characteristics of throttle when tap water is used as the working media. The researched throttles include cone poppet valve, ball valve, disc valve and dumping orifice. Operating condition includes poppet lift, working media, back pressure, medium temperature, etc. Because the vapourous pressure of water is much higher than that of oil, cavitation is easier to occur in water hydraulic elements and systems, so the effects of operating conditions on the cavitation characteristics of throttle are also researched.

  7. Monitoring tooth profile faults in epicyclic gearboxes using synchronously averaged motor currents: Mathematical modeling and experimental validation

    Science.gov (United States)

    Ottewill, J. R.; Ruszczyk, A.; Broda, D.

    2017-02-01

    Time-varying transmission paths and inaccessibility can increase the difficulty in both acquiring and processing vibration signals for the purpose of monitoring epicyclic gearboxes. Recent work has shown that the synchronous signal averaging approach may be applied to measured motor currents in order to diagnose tooth faults in parallel shaft gearboxes. In this paper we further develop the approach, so that it may also be applied to monitor tooth faults in epicyclic gearboxes. A low-degree-of-freedom model of an epicyclic gearbox which incorporates the possibility of simulating tooth faults, as well as any subsequent tooth contact loss due to these faults, is introduced. By combining this model with a simple space-phasor model of an induction motor it is possible to show that, in theory, tooth faults in epicyclic gearboxes may be identified from motor currents. Applying the synchronous averaging approach to experimentally recorded motor currents and angular displacements recorded from a shaft mounted encoder, validate this finding. Comparison between experiments and theory highlight the influence of operating conditions, backlash and shaft couplings on the transient response excited in the currents by the tooth fault. The results obtained suggest that the method may be a viable alternative or complement to more traditional methods for monitoring gearboxes. However, general observations also indicate that further investigations into the sensitivity and robustness of the method would be beneficial.

  8. Experimental Investigations on PV Powered SVM-DTC Induction Motor without AC Phase Current Sensors

    Directory of Open Access Journals (Sweden)

    T. Muthamizhan

    2014-05-01

    Full Text Available The paper presents a low-cost, phase-current reconstruction algorithm for space vector modulated direct torque controlled induction motor using the information obtained from only one shunt resistor which is in series with low side switches in a conventional three-phase inverter. The aim is to develop a low-cost high - performance induction motor drive. It uses the dc-link voltage and dc current to reconstruct the stator currents needed to estimate the motor flux and the electromagnetic torque. Photovoltaic arrays convert solar power to dc electric power; uses chopper and dc-ac inverter to fed three phase Induction Motor. The chopper used here is current fed full bridge boost dc-dc converter, which is preferred and extensively used in high voltage applications and advantageous over voltage fed converters. The inverter switches are controlled by PWM techniques obtained from SVM-DTC of IM. The experimental investigations are given to prove the ability of the proposed scheme of reproducing the performances of a SVM- DTC IM drive.

  9. Experimental and theoretical investigations on the singularity of the intensity factor of the current in high temperature superconductors

    Science.gov (United States)

    Zhang, Xingyi; Huang, Yi; Zhou, Jun; Zhou, Youhe

    2013-08-01

    This paper presents experimental and analytical investigations into the distribution of current around a through-edge crack located in an infinitely long cylindrical high temperature superconductor (HTS) on the basis of the Bean model. Current distributions around the crack in the HTS without deformation are obtained by a simple conformal mapping. It is shown that the current is singular at the tip of the crack. An intensity factor of the current is introduced to characterize the singularity, the order of which is equal to -1. Additionally, an experimental verification according to the trapped field distributions around the crack is carried out, and the experimental results show little difference with the theoretical analysis.

  10. The Development of Forms of Corporate Social Responsibility in Russia in the Current Economic Conditions

    Directory of Open Access Journals (Sweden)

    Natalya Arzumanova

    2015-02-01

    Full Text Available The article reveals the characteristic features of modern trends in the formation and implementation of corporate social responsibility in Russia in the current economic conditions, which is based on the fact that reasonable economic interests oriented business not only on maximizing profits, but also to improve their own macro - socio-economic, natural, political, through voluntary investment profits in the respective areas.

  11. MicroRNAs as Biomarkers for Psychiatric Conditions: A Review of Current Research

    Science.gov (United States)

    Hussain, Mariyah; Sreeram, Venkatesh

    2017-01-01

    Neural-derived exosomes can be used as diagnostic markers to screen for various psychiatric conditions. These intravenously injected exosomes carry the potential to cross the blood brain barrier and deliver miRNA molecules specifically to neurons, microglia, and oligodendrocytes in the brain, resulting in specific gene knockdown. Here the authors review and discuss the current research on microRNA molecules and the therapeutic roles they may potentially play in treating depression, bipolar disorder, and schizophrenia.

  12. Enhanced D-T supershot performance at high current using extensive lithium conditioning in TFTR

    Energy Technology Data Exchange (ETDEWEB)

    Mansfield, D.K.; Strachan, J.D.; Bell, M.G.; Scott, S.D.; Budny, R.; Bell, R.E.; Bitter, M.; Darrow, D.S.; Fredrickson, E.; Grek, B. [and others

    1995-05-01

    A substantial improvement in supershot fusion plasma performance has been realized by combining the enhanced confinement due to tritium fueling with the enhanced confinement due to extensive Li conditioning of the TFTR limiter. This combination has resulted in not only significantly higher global energy confinement times than had previously been obtained in high current supershots, but also the highest ratio of central fusion output power to input power observed to date.

  13. DC Link Current Estimation in Wind-Double Feed Induction Generator Power Conditioning System

    Directory of Open Access Journals (Sweden)

    MARIAN GAICEANU

    2010-12-01

    Full Text Available In this paper the implementation of the DC link current estimator in power conditioning system of the variable speed wind turbine is shown. The wind turbine is connected to double feed induction generator (DFIG. The variable electrical energy parameters delivered by DFIG are fitted with the electrical grid parameters through back-to-back power converter. The bidirectional AC-AC power converter covers a wide speed range from subsynchronous to supersynchronous speeds. The modern control of back-to-back power converter involves power balance concept, therefore its load power should be known in any instant. By using the power balance control, the DC link voltage variation at the load changes can be reduced. In this paper the load power is estimated from the dc link, indirectly, through a second order DC link current estimator. The load current estimator is based on the DC link voltage and on the dc link input current of the rotor side converter. This method presents certain advantages instead of using measured method, which requires a low pass filter: no time delay, the feedforward current component has no ripple, no additional hardware, and more fast control response. Through the numerical simulation the performances of the proposed DC link output current estimator scheme are demonstrated.

  14. Experimental results for improving the matrix condition using a hybrid optical system.

    Science.gov (United States)

    Klapp, Iftach; Mendlovic, David

    2012-03-01

    We present preliminary experimental results for implementing the "blurred trajectories" method on three parallel optics (PO) systems. The "main" system and "auxiliary" optics were simple laboratory graded lenses attached to an iris diaphragm. When applying the blurred trajectories method we first show an improvement in the matrix condition, as the matrix condition number decreased in a range of factors of 3 to 418 relative to the main system. Following that, image restoration by weak regularization was performed so that the system matrix condition dominated the restoration process. It was shown that the restoration results of the PO are better than those of the main system and the auxiliary optics separately. In addition, the quality of the restoration follows the system's matrix condition. The improvement in the matrix condition achieved by the PO system improved the immunity to detection noise. Finally, a comparison to Wiener filtering restoration shows that it is also generally inferior to the proposed method.

  15. Experimental Determination of DT Yield in High Current DD Dense Plasma Focii

    Energy Technology Data Exchange (ETDEWEB)

    Lowe, D. R. [National Security Technologies, LLC; Hagen, E. C. [National Security Technologies, LLC; Meehan, B. T. [National Security Technologies, LLC; Springs, R. K. [University of Nevada, Las Vegas; O' Brien, R. J. [University of Nevada, Las Vegas

    2013-06-18

    Dense Plasma Focii (DPF), which utilize deuterium gas to produce 2.45 MeV neutrons, may in fact also produce DT fusion neutrons at 14.1 MeV due to the triton production in the DD reaction. If beam-target fusion is the primary producer of fusion neutrons in DPFs, it is possible that ejected tritons from the first pinch will interact with the second pinch, and so forth. The 2 MJ DPF at National Security Technologies’ Losee Road Facility is able to, and has produced, over 1E12 DD neutrons per pulse, allowing an accurate measurement of the DT/DD ratio. The DT/DD ratio was experimentally verified by using the (n,2n) reaction in a large piece of praseodymium metal, which has a threshold reaction of 8 MeV, and is widely used as a DT yield measurement system1. The DT/DD ratio was experimentally determined for over 100 shots, and then compared to independent variables such as tube pressure, number of pinches per shot, total current, pinch current and charge voltage.

  16. Experimental demonstration of a new radiation mechanism: emission by an oscillating, accelerated, superluminal polarization current

    CERN Document Server

    Ardavan, A; Ardavan, H; Fopma, J; Halliday, D; Hayes, W

    2004-01-01

    We describe the experimental implementation of a superluminal ({\\it i.e.} faster than light {\\it in vacuo}) polarization current distribution that both oscillates and undergoes centripetal acceleration. Theoretical treatments lead one to expect that the radiation emitted from each volume element of such a polarization current will comprise a \\v{C}erenkov-like envelope with two sheets that meet along a cusp. The emission from the experimental machine is in good agreement with these expectations, the combined effect of the volume elements leading to tightly-defined beams of a well-defined geometry, determined by the source speed and trajectory. In addition, over a restricted range of angles, we detect the presence of cusps in the emitted radiation. These are due to the detection over a short time period (in the laboratory frame) of radiation emitted over a considerably longer period of source time. Consequently, the intensity of the radiation at these angles was observed to decline more slowly with increasing d...

  17. Dynamics of Instantaneous Condensation in the ZRP Conditioned on an Atypical Current

    Directory of Open Access Journals (Sweden)

    Rosemary J. Harris

    2013-11-01

    Full Text Available Using a generalized Doob’s h-transform we consider the zero-range process (ZRP conditioned to carry an atypical current, with focus on the regime where the Gallavotti-Cohen symmetry loses its validity. For a single site we compute explicitly the boundary injection and absorption rates of an effective process which maps to a biased random walk. Our approach provides a direct probabilistic confirmation of the theory of “instantaneous condensation” which was proposed some while ago to explain the dynamical origin of the the failure of the Gallavotti-Cohen symmetry for high currents in the ZRP. However, it turns out that for stochastic dynamics with infinite state space care needs to be taken in the application of the Doob’s transform—we discuss in detail the sense in which the effective dynamics can be interpreted as “typical” for different regimes of the current phase diagram.

  18. The residential electricity sector in Denmark: A description of current conditions

    DEFF Research Database (Denmark)

    Kitzing, Lena; Katz, Jonas; Schröder, Sascha Thorsten

    We provide an overview of the current conditions and framework for residential electricity consumption in Denmark. This includes a general overview of the sector, the retail market and the regulatory framework. We describe the regulations currently in place and changes which have been decided for...... in the area, which are listed in the Glossary towards the end of the report. We also attach a list and description of the major sources of information and data that can be obtained and downloaded for analysis of the Danish residential electricity sector.......We provide an overview of the current conditions and framework for residential electricity consumption in Denmark. This includes a general overview of the sector, the retail market and the regulatory framework. We describe the regulations currently in place and changes which have been decided...... for the coming years. The information and data described are all publicly available, though much of it only in Danish language. This description is to our knowledge one of the first comprehensive overviews of the Danish residential sector in English language. We have translated a number of terms commonly used...

  19. Gas migration in KBS-3 buffer bentonite. Sensitivity of test parameters to experimental boundary conditions

    Energy Technology Data Exchange (ETDEWEB)

    Harrington, J.F.; Horseman, S.T. [British Geological Survey, Nottingham (United Kingdom)

    2003-01-01

    In the current Swedish repository design concept, hydrogen gas can be generated inside a waste canister by anaerobic corrosion of the ferrous metal liner. If the gas generation rate exceeds the diffusion rate of gas molecules in the buffer porewater, gas will accumulate in the void-space of a canister until its pressure becomes large enough for it to enter the bentonite as a discrete gaseous phase. Three long tenn gas injection tests have been performed on cylinders of pre-compacted MX80 bentonite. Two of these tests were undertaken using a custom-designed constant volume and radial flow (CVRF) apparatus. Gas was injected at a centrally located porous filter installed in the clay before hydration. Arrangements were made for gas to flow to three independently monitored sink-filter arrays mounted around the specimen. Axial and radial total stresses and internal porewater pressures were continuously monitored. Breakthrough and peak gas pressures were substantially larger than the sum of the swelling pressure and the external porewater. The third test was performed. using an apparatus which radially constrains the specimen during gas flow. Observed sensitivity of the breakthrough and peak gas pressures to the test boundary conditions suggests that gas entry must be accompanied by dilation of the bentonite fabric. In other words, there is a tendency for the volume of the specimen to increase during this process. The experimental evidence is consistent with the flow of gas along a relatively small number of crack-like pathways which propagate through the clay as gas pressure increases. Gas entry and breakthrough under constant volume boundary conditions causes a substantial increase in the total stress and the internal porewater pressure. It is possible to determine the point at which gas enters the clay by monitoring changes in these parameters. Localisation of gas flow within multiple pathways results, in nonuniform discharge rates at the sinks. When gas injection

  20. An experimental investigation of the dynamics of submarine leveed channel initiation as sediment-laden density currents experience sudden unconfinement

    Energy Technology Data Exchange (ETDEWEB)

    Rowland, Joel C [Los Alamos National Laboratory; Hilley, George E [STANFORD UNIV; Fildani, Andrea [CHEVRON ETC

    2009-01-01

    Leveed submarine channels play a critical role in the transfer of sediment from the upper continental slopes to interslope basins and ultimately deepwater settings. Despite a reasonable understanding of how these channels grow once established, how such channels initiate on previously unchannelized portions of the seafloor remains poorly understood. We conducted a series of experiments that elucidate the influence of excess density relative to flow velocity on the dynamics of, and depositional morphologies arising from, density currents undergoing sudden unconfinement across a sloped bed. Experimental currents transported only suspended sediment across a non-erodible substrate. Under flow conditions ranging from supercritical to subcritical (bulk Richardson numbers of 0.02 to 1.2) our experiments failed to produce deposits resembling or exhibiting the potential to evolve into self-formed leveed channels. In the absence of excess density, a submerged sediment-laden flow produced sharp crested lateral deposits bounding the margins of the flow for approximately a distance of two outlet widths down basin. These lateral deposits terminated in a centerline deposit that greatly exceeded marginal deposits in thickness. As excess density increased relative to the outlet velocity, the rate of lateral spreading of the flow increased relative to the downstream propagation of the density current, transitioning from a narrow flow aligned with the channel outlet to a broad radially expanding flow. Coincident with these changes in flow dynamics, the bounding lateral deposits extended for shorter distances, had lower, more poorly defined crests that were increasingly wider in separation than the initial outlet, and progressively became more oblong rather than linear. Based on our results, we conclude that leveed channels cannot initiate from sediment-laden density currents under strictly depositional conditions. Partial confinement of these currents appears to be necessary to

  1. The Managerial Roles of Sports Clubs CEOs in the Current and Desirable Conditions

    Directory of Open Access Journals (Sweden)

    Mahboobeh Surani

    2014-10-01

    Full Text Available Today, the proper playing of managerial roles is of special importance in effective and successful management of sports clubs. The present paper aimed to study the managerial roles of sports clubs CEOs in Isfahan Province in the current and desirable conditions. Statistical population included all managers and directors of Sepahan, Zobahan, Foolad Mahan, and Gitipasand sports clubs (N=83, which was considered as the sample as well. An author-made questionnaire with 31 items on a Likert’s 5-point scale was used for data collection. Validity of the questionnaire was confirmed by 15 experts and professors and its reliability was obtained α=0.94 by Cronbach’s alpha coefficient. 84 questionnaires were handed out among all managers and directors of the studied sports clubs, 76 of which (91.5% was returned. The results showed that priority of CEOs roles, respectively, include decisional role (4.16±0.61, informational role (4.09±0.56, and interpersonal role (4.03±0.67. The results of factor analysis also indicated that the roles of entrepreneurship, data collection, spokesman, and allocation of resources, respectively, are the most important roles of CEOs and negotiation, figurehead, and leadership roles are the least important ones in the desirable conditions. A significant difference was observed between the roles of managers in the current and desirable conditions (Sig.=0.001. The results suggested that the respondents’ expectations of sports clubs CEOs’ roles in desirable conditions is beyond their perceptions in the current situation. It can be generally concluded that sports clubs CEOs need to better perform all managerial roles, especially decisional role.

  2. Clinical and experimental studies on polyherbal formulations for diabetes:current status and future prospective

    Institute of Scientific and Technical Information of China (English)

    Ahmad Ghorbani

    2014-01-01

    Diabetes is a leading cause of morbidity and mortality in the world. There is currently an active search for antidiabetic drugs with greater effectiveness with fewer and less adverse side effects. Although numerous individual herbs have been experimentally or clinically reported to possess antidiabetic effects, considerably less research has been conducted on polyherbal compounds. It is believed that herbal compounds containing multiple plant products have synergistic antidiabetic effects and could enhance the desired actions. Several polyherbal formulations have been studied as therapeutic agents in diabetes management. To describe the current state of research on polyherbal compounds in the treatment of diabetes, an extensive review of literature was undertaken on several major databases. This paper presents what is known about the efifcacy of these polyherbal formulations and compare their antidiabetic effects with those of current oral hypoglycemic drugs as reference. The percent decrease in blood glucose, lipids and other biochemical parameters achieved by each product in diabetic animals and patients is reported. Also, the possible mechanisms responsible for hypoglycemic action of polyherbal formulations are discussed.

  3. Experimental study on hydrodynamic characteristics of vertical-axis floating tidal current energy power generation device

    Science.gov (United States)

    Ma, Yong; Li, Teng-fei; Zhang, Liang; Sheng, Qi-hu; Zhang, Xue-wei; Jiang, Jin

    2016-10-01

    To study the characteristics of attenuation, hydrostatic towage and wave response of the vertical-axis floating tidal current energy power generation device (VAFTCEPGD), a prototype is designed and experiment is carried out in the towing tank. Free decay is conducted to obtain attenuation characteristics of the VAFTCEPGD, and characteristics of mooring forces and motion response, floating condition, especially the lateral displacement of the VAFTCEPGD are obtained from the towing in still water. Tension response of the #1 mooring line and vibration characteristics of the VAFTCEPGD in regular waves as well as in level 4 irregular wave sea state with the current velocity of 0.6 m/s. The results can be reference for theoretical study and engineering applications related to VAFTCEPGD.

  4. Uncertainties in Predicting Rice Yield by Current Crop Models Under a Wide Range of Climatic Conditions

    Science.gov (United States)

    Li, Tao; Hasegawa, Toshihiro; Yin, Xinyou; Zhu, Yan; Boote, Kenneth; Adam, Myriam; Bregaglio, Simone; Buis, Samuel; Confalonieri, Roberto; Fumoto, Tamon; Gaydon, Donald; Marcaida, Manuel, III; Nakagawa, Hiroshi; Oriol, Philippe; Ruane, Alex C.; Ruget, Francoise; Singh, Balwinder; Singh, Upendra; Tang, Liang; Tao, Fulu; Wilkens, Paul; Yoshida, Hiroe; Zhang, Zhao; Bouman, Bas

    2014-01-01

    Predicting rice (Oryza sativa) productivity under future climates is important for global food security. Ecophysiological crop models in combination with climate model outputs are commonly used in yield prediction, but uncertainties associated with crop models remain largely unquantified. We evaluated 13 rice models against multi-year experimental yield data at four sites with diverse climatic conditions in Asia and examined whether different modeling approaches on major physiological processes attribute to the uncertainties of prediction to field measured yields and to the uncertainties of sensitivity to changes in temperature and CO2 concentration [CO2]. We also examined whether a use of an ensemble of crop models can reduce the uncertainties. Individual models did not consistently reproduce both experimental and regional yields well, and uncertainty was larger at the warmest and coolest sites. The variation in yield projections was larger among crop models than variation resulting from 16 global climate model-based scenarios. However, the mean of predictions of all crop models reproduced experimental data, with an uncertainty of less than 10 percent of measured yields. Using an ensemble of eight models calibrated only for phenology or five models calibrated in detail resulted in the uncertainty equivalent to that of the measured yield in well-controlled agronomic field experiments. Sensitivity analysis indicates the necessity to improve the accuracy in predicting both biomass and harvest index in response to increasing [CO2] and temperature.

  5. An experimental comparison of modelling techniques for speaker recognition under limited data condition

    Indian Academy of Sciences (India)

    H S Jayanna; S R Mahadeva Prasanna

    2009-10-01

    Most of the existing modelling techniques for the speaker recognition task make an implicit assumption of sufficient data for speaker modelling and hence may lead to poor modelling under limited data condition. The present work gives an experimental evaluation of the modelling techniques like Crisp Vector Quantization (CVQ), Fuzzy Vector Quantization (FVQ), Self-Organizing Map (SOM), Learning Vector Quantization (LVQ), and Gaussian Mixture Model (GMM) classifiers. An experimental evaluation of the most widely used Gaussian Mixture Model–Universal Background Model (GMM–UBM) is also made. The experimental knowledge is then used to select a subset of classifiers for obtaining the combined classifiers. It is proposed that the combined LVQ and GMM–UBM classifier provides relatively better performance compared to all the individual as well as combined classifiers.

  6. Comparative assessment of the effectiveness of modern neuroprotectors in conditions of experimental chronic cerebral ischemia

    Directory of Open Access Journals (Sweden)

    A. V. Demchenko

    2015-04-01

    Full Text Available Modern pharmacological influence on the pathological changes in cerebral ischemia is actual task of the modern neurology. Aim. To make a comparative assessment of the effectiveness of modern neuroprotectors in conditions of experimental chronic cerebral ischemia. Methods and results. Experimental study of the neuroprotective effects of the citicoline, cortexin and tiocetam on the cognitive functions on the model of the chronic cerebral ischemia was conducted on 75 white rats. Biochemical, immunoassay, pharmacological, statistical methods were used. Conclusion. Obtained results showed citicoline, cortexin and tiocetam ability to positively influence on the molecular-biochemical changes in the brain cortex with ischemia. This resulted in the glutathione-dependent enzymes activity increase, recover of the thiol-disulfide system balance, nitrotyrosine concentration decrease, improvement of the cognitive function in the experimental animals.

  7. Current Conditions Risk Assessment for the 300-FF-5 Groundwater Operable Unit

    Energy Technology Data Exchange (ETDEWEB)

    Miley, Terri B.; Bunn, Amoret L.; Napier, Bruce A.; Peterson, Robert E.; Becker, James M.

    2007-11-01

    This report updates a baseline risk assessment for the 300 Area prepared in 1994. The update includes consideration of changes in contaminants of interest and in the environment that have occurred during the period of interim remedial action, i.e., 1996 to the present, as well as the sub-regions, for which no initial risk assessments have been conducted. In 1996, a record of decision (ROD) stipulated interim remedial action for groundwater affected by releases from 300 Area sources, as follows: (a) continued monitoring of groundwater that is contaminated above health-based levels to ensure that concentrations continue to decrease, and (b) institutional controls to ensure that groundwater use is restricted to prevent unacceptable exposure to groundwater contamination. In 2000, the groundwater beneath the two outlying sub-regions was added to the operable unit. In 2001, the first 5-year review of the ROD found that the interim remedy and remedial action objectives were still appropriate, although the review called for additional characterization activities. This report includes a current conditions baseline ecological and human health risk assessment using maximum concentrations in the environmental media of the 300-FF-5 Operable Unit and downstream conditions at the City of Richland, Washington. The scope for this assessment includes only current measured environmental concentrations and current use scenarios. Future environmental concentrations and future land uses are not considered in this assessment.

  8. Experimental Simulation of the Behaviour of Diagnostic First Mirrors Fabricated of Different Metals for ITER Conditions

    OpenAIRE

    Voitsenya, V.; Bardamid, A. F.; Donne, A. J. H.

    2016-01-01

    In the experimental fusion reactor ITER, the plasma-facing component of each optical and/or laser diagnostic needs to be based on reflective optics with at least one mirror (first mirror) facing the thermonuclear plasma. The different kinds of radiation emanating from the burning plasma (neutrons, neutral atoms, electromagnetic radiation) create hostile operating conditions for the first mirrors. Therefore, a special program has been set up under the ITER framework aimed at solving the first ...

  9. Experimental simulation of the condensation and metamorphism of seasonal CO2 condensates under martian conditions.

    Science.gov (United States)

    Grisolle, F.; Schmitt, B.; Beck, P.; Philippe, S.; Brissaud, O.

    2014-04-01

    An experimental set-up, CARBON-IR, has been developed in order to perform the condensation and metamorphism of CO2 condensates in various controlled martian conditions at, or out of, equilibrium. The sample texture is monitored and near-infrared reflectance spectra are recorded. We present a first set of experiments aimed to simulate the formation of compact translucent slabs by condensation of CO2 gas, the metamorphism of CO2 snow, as well as their sublimation.

  10. Experimental Investigation and Modelling for the Optimisation of Conduction Cooled HTS Hybrid Current Leads for SMES

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    It′s important that HTS tapes have lower thermal conductivity and higher transversal resistivity in order to reduce the heat leaks conducted along the tapes and AC losses in the high temperature superconducting system conduction-cooled by GM coolers. This paper presents an experimental investigation into the effects of pure Ag and AgAu alloys sheath materials on the properties of Bi(2223) multifilamentary tapes and the optimisation of conduction-cooled hybrid current leads made from copper and Bi(2223)/Ag or Bi(2223)/AgAu tapes. The thermal conductivity of the tapes were measured by cryogenic steady heat flux method and the resistance was measured by using standard DC four-probe method at low temperature. The results showed that the reduction of thermal conductivity by the addition of Au into the sheath material of Bi(2223) tapes was 650%, 750% and 850% lower than that of pure Ag sheathed Bi(2223) tapes and the increase of resistivity was 4.9, 10 and 19.4 times higher than that of pure Ag for the addition of 2.20%, 5.70% and 10.70%Au(atom ratio) respectively. And the study also attempts to optimise thermodynamically the conduction-cooled hybrid current lead by using a developed model, which took the irreversibility of commercial GM coolers, the contact resistance and thermal conductance into account. Predictions from the model showed that AgAu alloys were suitable candidate materials to replace Ag as sheath material of Bi(2223) tapes applied in HTS current leads. In addition, Bi(2223)/AgAu was a suitable material to be applied as the HTS section of hybrid current leads in conduction-cooled superconducting electric systems.

  11. Experimental and numerical examination of eddy (Foucault) currents in rotating micro-coils: Generation of heat and its impact on sample temperature.

    Science.gov (United States)

    Aguiar, Pedro M; Jacquinot, Jacques-François; Sakellariou, Dimitris

    2009-09-01

    The application of nuclear magnetic resonance (NMR) to systems of limited quantity has stimulated the use of micro-coils (diameter Foucault (eddy) currents, which generate heat. We report the first data acquired with a 4mm MACS system and spinning up to 10kHz. The need to spin faster necessitates improved methods to control heating. We propose an approximate solution to calculate the power losses (heat) from the eddy currents for a solenoidal coil, in order to provide insight into the functional dependencies of Foucault currents. Experimental tests of the dependencies reveal conditions which result in reduced sample heating and negligible temperature distributions over the sample volume.

  12. In vivo screening of extracellular matrix components produced under multiple experimental conditions implanted in one animal.

    Science.gov (United States)

    Higuera, Gustavo A; Hendriks, Jeanine A A; van Dalum, Joost; Wu, Ling; Schotel, Roka; Moreira-Teixeira, Liliana; van den Doel, Mirella; Leijten, Jeroen C H; Riesle, Jens; Karperien, Marcel; van Blitterswijk, Clemens A; Moroni, Lorenzo

    2013-06-01

    Animal experiments help to progress and ensure safety of an increasing number of novel therapies, drug development and chemicals. Unfortunately, these also lead to major ethical concerns, costs and limited experimental capacity. We foresee a coercion of all these issues by implantation of well systems directly into vertebrate animals. Here, we used rapid prototyping to create wells with biomaterials to create a three-dimensional (3D) well-system that can be used in vitro and in vivo. First, the well sizes and numbers were adjusted for 3D cell culture and in vitro screening of molecules. Then, the functionality of the wells was evaluated in vivo under 36 conditions for tissue regeneration involving human mesenchymal stem cells (hMSCs) and bovine primary chondrocytes (bPCs) screened in one animal. Each biocompatible well was controlled to contain μl-size volumes of tissue, which led to tissue penetration from the host and tissue formation under implanted conditions. We quantified both physically and biologically the amounts of extracellular matrix (ECM) components found in each well. Using this new concept the co-culture of hMSCs and bPCs was identified as a positive hit for cartilage tissue repair, which was a comparable result using conventional methods. The in vivo screening of candidate conditions opens an entirely new range of experimental possibilities, which significantly abates experimental animal use and increases the pace of discovery of medical treatments.

  13. Ischemic conditioning protects from axoglial alterations of the optic pathway induced by experimental diabetes in rats.

    Directory of Open Access Journals (Sweden)

    Diego C Fernandez

    Full Text Available Diabetic retinopathy is a leading cause of blindness. Visual function disorders have been demonstrated in diabetics even before the onset of retinopathy. At early stages of experimental diabetes, axoglial alterations occur at the distal portion of the optic nerve. Although ischemic conditioning can protect neurons and synaptic terminals against ischemic damage, there is no information on its ability to protect axons. We analyzed the effect of ischemic conditioning on the early axoglial alterations in the distal portion of the optic nerve induced by experimental diabetes. Diabetes was induced in Wistar rats by an intraperitoneal injection of streptozotocin. Retinal ischemia was induced by increasing intraocular pressure to 120 mm Hg for 5 min; this maneuver started 3 days after streptozotocin injection and was weekly repeated in one eye, while the contralateral eye was submitted to a sham procedure. The application of ischemia pulses prevented a deficit in the anterograde transport from the retina to the superior colliculus, as well as an increase in astrocyte reactivity, ultraestructural myelin alterations, and altered morphology of oligodendrocyte lineage in the optic nerve distal portion at early stages of experimental diabetes. Ischemia tolerance prevented a significant decrease of retinal glutamine synthetase activity induced by diabetes. These results suggest that early vision loss in diabetes could be abated by ischemic conditioning which preserved axonal function and structure.

  14. Experimental calibration and validation of sewer/surface flow exchange equations in steady and unsteady flow conditions

    Science.gov (United States)

    Rubinato, Matteo; Martins, Ricardo; Kesserwani, Georges; Leandro, Jorge; Djordjević, Slobodan; Shucksmith, James

    2017-09-01

    The linkage between sewer pipe flow and floodplain flow is recognised to induce an important source of uncertainty within two-dimensional (2D) urban flood models. This uncertainty is often attributed to the use of empirical hydraulic formulae (the one-dimensional (1D) weir and orifice steady flow equations) to achieve data-connectivity at the linking interface, which require the determination of discharge coefficients. Because of the paucity of high resolution localised data for this type of flows, the current understanding and quantification of a suitable range for those discharge coefficients is somewhat lacking. To fulfil this gap, this work presents the results acquired from an instrumented physical model designed to study the interaction between a pipe network flow and a floodplain flow. The full range of sewer-to-surface and surface-to-sewer flow conditions at the exchange zone are experimentally analysed in both steady and unsteady flow regimes. Steady state measured discharges are first analysed considering the relationship between the energy heads from the sewer flow and the floodplain flow; these results show that existing weir and orifice formulae are valid for describing the flow exchange for the present physical model, and yield new calibrated discharge coefficients for each of the flow conditions. The measured exchange discharges are also integrated (as a source term) within a 2D numerical flood model (a finite volume solver to the 2D Shallow Water Equations (SWE)), which is shown to reproduce the observed coefficients. This calibrated numerical model is then used to simulate a series of unsteady flow tests reproduced within the experimental facility. Results show that the numerical model overestimated the values of mean surcharge flow rate. This suggests the occurrence of additional head losses in unsteady conditions which are not currently accounted for within flood models calibrated in steady flow conditions.

  15. Issues in current User Equilibrium models and introduction of the Restricted Stochastic User Equilibrium conditions

    DEFF Research Database (Denmark)

    Rasmussen, Thomas Kjær; Watling, David P.; Prato, Carlo Giacomo

    -off is strictly enforced: in a time-only model, if the current equilibrium travel time is 15.3 minutes, then adding a route with travel time of 15.4 minutes will have no impact on routing behaviour, whereas in practice (because of uncertainty, variability and unobserved attributes) the new route is likely....... This issue is further complicated by the fact that typically only a sub-set of possible routes will be identified in numerical algorithms solving for SUE. In the current study, we present new alternative forms of SUE conditions that permit unused alternatives, accommodate behaviour on used alternatives...... algorithms to the behaviourally sound SUE and the efficiency of solution algorithms to the DUE, we introduce a transformation of the cost function. This transformation function opens up a larger array of possible solution algorithms to the SUE, as it allows us to apply any path-based DUE solution algorithm...

  16. Conditions for Photospherically Driven Alfvenic Oscillations to Heat the Solar Chromosphere by Pedersen Current Dissipation

    CERN Document Server

    Goodman, Michael L

    2014-01-01

    A magnetohydrodynamic model that includes a complete electrical conductivity tensor is used to estimate conditions for photospherically driven, linear, non-plane Alfvenic oscillations extending from the photosphere to the lower corona to drive a chromospheric heating rate due to Pedersen current dissipation that is comparable to the net chromospheric net radiative loss of $\\sim 10^7$ ergs-cm$^{-2}$-sec$^{-1}$. The heating rates due to electron current dissipation in the photosphere and corona are also computed. The wave amplitudes are computed self-consistently as functions of an inhomogeneous background (BG) atmosphere. The effects of the conductivity tensor are resolved numerically using a resolution of 3.33 m. The oscillations drive a chromospheric heating flux $F_{Ch} \\sim 10^7 - 10^8$ ergs-cm$^{-2}$-sec$^{-1}$ at frequencies $\

  17. Childhood conditions and current physical performance among non-institutionalized individuals aged 50+ in Israel

    Science.gov (United States)

    2017-01-01

    Adverse socioeconomic conditions in childhood have been previously linked with high risk of various health conditions. However, the association with future physical function has been less studied. Hand grip strength and chair-rising time are objective measures of physical capability indicating current and future health outcomes. The aim of this study was to test the hypothesis that perceived socio-economic status in childhood is related to current measures of physical function, among Israeli participants of the Survey of Health, Ageing and Retirement in Europe project. The study included 2300 participants aged 50 years or older (mean age 68 ± 10; 56 % women). Generalized linear regression models were used to examine the associations of childhood wealth and number of books in residence with grip strength and time to complete five rises from a chair. Logistic regression models were used to assess the relationships between the early life conditions and the ability to perform the physical tests. Adjustment was made for current income or household wealth, and for demographic, anthropometric, health, and life-style measures. Being wealthy and having a large number of books at home in childhood was associated with a stronger hand grip and a better chair-rise test performance. These associations were more robust in women compared to men, and persisted after adjustment for potential covariates. In addition, childhood wealth and number of books were associated with lower risk of being unable to perform the tests. Thus, early-life programming may contribute to physical function indicators in mid- and late-life.

  18. Electric Current Activated Combustion Synthesis and Chemical Ovens Under Terrestrial and Reduced Gravity Conditions

    Science.gov (United States)

    Unuvar, C.; Fredrick, D.; Anselmi-Tamburini, U.; Manerbino, A.; Guigne, J. Y.; Munir, Z. A.; Shaw, B. D.

    2004-01-01

    Combustion synthesis (CS) generally involves mixing reactants together (e.g., metal powders) and igniting the mixture. Typically, a reaction wave will pass through the sample. In field activated combustion synthesis (FACS), the addition of an electric field has a marked effect on the dynamics of wave propagation and on the nature, composition, and homogeneity of the product as well as capillary flow, mass-transport in porous media, and Marangoni flows, which are influenced by gravity. The objective is to understand the role of an electric field in CS reactions under conditions where gravity-related effects are suppressed or altered. The systems being studied are Ti+Al and Ti+3Al. Two different ignition orientations have been used to observe effects of gravity when one of the reactants becomes molten. This consequentially influences the position and concentration of the electric current, which in turn influences the entire process. Experiments have also been performed in microgravity conditions. This process has been named Microgravity Field Activated Combustion Synthesis (MFACS). Effects of gravity have been demonstrated, where the reaction wave temperature and velocity demonstrate considerable differences besides the changes of combustion mechanisms with the different high currents applied. Also the threshold for the formation of a stable reaction wave is increased under zero gravity conditions. Electric current was also utilized with a chemical oven technique, where inserts of aluminum with minute amounts of tungsten and tantalum were used to allow observation of effects of settling of the higher density solid particles in liquid aluminum at the present temperature profile and wave velocity of the reaction.

  19. Experimental Study on Vortex-Induced Vibrations of Submarine Pipeline near Seabed Boundary in Ocean Currents

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Unlike most previous studies on vortex-induced vibrations of a cylinder far from a boundary, this paper focuses on the influences of close proximity of a submarine pipeline to a rigid seabed boundary upon the dynamic responses of the pipeline in ocean currents. The effects of gap-to-diameter ratio and those of the stability parameter on the amplitude and frequency responses of a pipeline are investigated experimentally with a novel hydro-elastic facility. A comparison is made between the present experimental results of the amplitude and frequency responses for the pipes with seabed boundary effects and those for wall-free cylinders given by Govardhan and Williamson (2000) and Anand (1985). The comparison shows that the close proximity of a pipeline to seabed has much influence on the vortex-induced vibrations of the pipeline. Both the width of the lock-in ranges in terms of Vr and the dimensionless amplitude ratio Amax/D become larger with the decrease of the gap-to-diameter ratio e/D. Moreover, the vibration of the pipeline becomes easier to occur and its amplitude response becomes more intensive with the decrease of the stability parameter, while the pipeline frequency responses are affected slightly by the stability parameter.

  20. Possibilities of pharmacologic correction of cognitive disorders in conditions of experimental equivalent of multiple sclerosis

    Directory of Open Access Journals (Sweden)

    Nefyodov A.A.

    2015-06-01

    Full Text Available A comparative analysis of the impact of citicoline, ±-lipoic acid, nicergoline, donepezil and colloidal solution of nano-silver (CSNS on the processes of learning and consolidation of memorable track in the test of the conditional reaction of passive avoidance (CRPA in conditions of experimental allergic encephalomyelitis (EAE was conducted. Testing of passive defensive skill was performed on days 12 and 20 after the induction of EAE. To assess the impact of drugs on the inputted information processes the investigated substances were administered intragastrically (CSNS - intraperitoneally once daily in the definite dose from the second to the day 10 after the induction of EAE (latent phase of the disease, and assessing processes of conditional skill preserving, further administration of drugs by the day 20 of the experiment (average duration of EAE was used. A positive effect of citicoline, ±-lipoic acid, nicergoline and donepezil on the input information processes and the ability to prevent accelerated extinction of acquired contingent skill in the conditions of experimental pathology was established. Drugs statistically significantly increased duration of the latent period of CRPA in comparison with a group of active control by 49%, 43%, 39% and 34%, respectively. Here with preparations were characterized by a high coefficient of antiamnesic activity, by the end of the experiment it was recorded at the level of 95% (citicoline, 81% (±-lipoic acid, 76% (nicergoline and 53% (donepezil. It is shown that the ability to prevent development of cognitive impairment in conditions of experimental equivalent of multiple sclerosis decreases in the number of citicoline (500 mg/kg > ±-lipoic acid (50 mg/kg H nicergoline (10 mg/kg > donepezil (10 mg/kg.

  1. Proportional integral plus multi-frequency resonant current controller for grid-connected voltage source converter under imbalanced and distorted supply voltage conditions

    Institute of Scientific and Technical Information of China (English)

    Jia-bing HU; Wei ZHANG; Hong-sheng WANG; Yi-kang HE; Lie XU

    2009-01-01

    This paper proposes a current control scheme for a grid-connected pulse width modulator (PWM) voltage source converter (GC-VSC) under imbalanced and distorted supply voltage conditions. The control scheme is implemented in the positive synchronously rotating reference frame and composed of a single proportional integral (PI) regulator and multi-frequency resonant controllers tuned at the frequencies of 2ω and 6ω, respectively. The experimental results, with the target of eliminating the active power oscillations and current harmonics on a prototype GC-VSC system, validate the feasibility of the proposed current control scheme during supply voltage imbalance and distortion.

  2. Experimental determination of two-dimensional critical current density distribution in YBCO coated conductors

    Energy Technology Data Exchange (ETDEWEB)

    Amemiya, Naoyuki; Shinkai, Yoshichika [Faculty of Engineering, Yokohama National University, Tokiwadai, Hodogaya, Yokohama (Japan); Iijima, Yasuhiro; Kakimoto, Kazuomi; Takeda, Kaoru [Materials Research Laboratory, Fujikura Ltd., Kiba, Koto, Tokyo (Japan)

    2001-08-01

    The critical current density (J{sub c}) distribution in YBCO coated conductors is attracting interest from the viewpoint of its influence on their AC loss characteristics as well as from material science and process engineering. A two-dimensional J{sub c} distribution in a YBCO coated conductor made by the IBAD (ion-beam assisted deposition) and the PLD (pulse-laser deposition) method can be determined by the magnetic-knife method with spatial resolutions of 0.2 mm lateral and 10 mm longitudinal directions, respectively. In an up-to-date 80A-class YBCO coated conductor, the J{sub c} is relatively uniform in the central part and reaches mbox{l_brace}7$x$10{sup 9} A m{sup -2}, {r_brace} while the J{sub c} fluctuates spatially in the central part of a tape fabricated earlier and with less critical current. Near the edges of the tapes, the J{sub c} is higher or lower than in the central part and the experimentally determined J{sub c} distributions are far from uniform. This suggests that a presumption of a uniform J{sub c} for AC loss estimations is not always reasonable and can lead to a large error in the estimated AC losses. (author)

  3. Experimental and numerical assessment of low-frequency current distributions from UMTS and GSM mobile phones.

    Science.gov (United States)

    Gosselin, Marie-Christine; Kühn, Sven; Kuster, Niels

    2013-12-07

    The evaluation of the exposure from mobile communication devices requires consideration of electromagnetic fields (EMFs) over a broad frequency range from dc to GHz. Mobile phones in operation have prominent spectral components in the low-frequency (LF) and radio-frequency (RF) ranges. While the exposure to RF fields from mobile phones has been comprehensively assessed in the past, the LF fields have received much less attention. In this study, LF fields from mobile phones are assessed experimentally and numerically for the global system for mobile (GSM) and universal mobile telecommunications system (UMTS) communication systems and conclusions about the global (LF and RF) EMF exposure from both systems are drawn. From the measurements of the time-domain magnetic fields, it was found that the contribution from the audio signal at a normal speech level, i.e., -16 dBm0, is the same order of magnitude as the fields induced by the current bursts generated from the implementation of the GSM communication system at maximum RF output level. The B-field induced by currents in phones using the UMTS is two orders of magnitude lower than that induced by GSM. Knowing that the RF exposure from the UMTS is also two orders of magnitude lower than from GSM, it is now possible to state that there is an overall reduction of the exposure from this communication system.

  4. Experimental challenges to theories of classical conditioning: application of an attentional model of storage and retrieval.

    Science.gov (United States)

    Schmajuk, Nestor A; Larrauri, José A

    2006-01-01

    Several studies have recently challenged the accuracy of traditional models of classical conditioning that account for some experimental data in terms of a storage deficit. Among other results, it has been reported that extinction of the blocking or overshadowing stimulus results in the recovery of the response to the blocked or overshadowed stimulus, backward blocking shows spontaneous recovery, extinction of the training context results in the recovery from latent inhibition, interposing a delay between conditioning and testing in latent inhibition increases latent inhibition, and latent inhibition antagonizes overshadowing. An existing neural network model of classical conditioning (N. A. Schmajuk, Y. Lam, & J. A. Gray, 1996), which includes an attentional mechanism controlling both storage and retrieval of associations, is able to quantitatively describe these results.

  5. Quantum versus classical foundation of statistical mechanics under experimentally realistic conditions.

    Science.gov (United States)

    Reimann, Peter; Evstigneev, Mykhaylo

    2013-11-01

    Focusing on isolated macroscopic systems, described in terms of either a quantum mechanical or a classical model, our two key questions are how far does an initial ensemble (usually far from equilibrium and largely unknown in detail) evolve towards a stationary long-time behavior (equilibration) and how far is this steady state in agreement with the microcanonical ensemble as predicted by statistical mechanics (thermalization). A recently developed quantum mechanical treatment of the problem is briefly summarized, putting particular emphasis on the realistic modeling of experimental measurements and nonequilibrium initial conditions. Within this framework, equilibration can be proven under very weak assumptions about those measurements and initial conditions, while thermalization still requires quite strong additional hypotheses. An analogous approach within the framework of classical mechanics is developed and compared with the quantum case. In particular, the assumptions to guarantee classical equilibration are now rather strong, while thermalization then follows under relatively weak additional conditions.

  6. Comparison of experimental and theoretical reaction rail currents, rail voltages, and airgap fields for the linear induction motor research vehicle

    Science.gov (United States)

    Elliott, D. G.

    1977-01-01

    Measurements of reaction rail currents, reaction rail voltages, and airgap magnetic fields in tests of the Linear Induction Motor Research Vehicle (LIMRV) were compared with theoretical calculations from the mesh/matrix theory. It was found that the rail currents and magnetic fields predicted by the theory are within 20 percent of the measured currents and fields at most motor locations in most of the runs, but differ by as much as a factor of two in some cases. The most consistent difference is a higher experimental than theoretical magnetic field near the entrance of the motor and a lower experimental than theoretical magnetic field near the exit. The observed differences between the theoretical and experimental magnetic fields and currents do not account for the differences of as much as 26 percent between the theoretical and experimental thrusts.

  7. Bora-induced currents corresponding to different synoptic conditions above the Adriatic

    Energy Technology Data Exchange (ETDEWEB)

    Beg Paklar, G.; Dadic, V.; Grbec, B. [Inst. of Oceanography and Fisheries, Split (Croatia); Bajic, A. [Meteorological and Hydrological Service of Croatia, Zagreb (Croatia); Orlic, M. [Andrija Mohorovicic Geophysical Inst., Faculty of Science, Univ. of Zagreb, Zagreb (Croatia)

    2005-07-01

    The Bora wind field is characterised by strong vorticity and divergence. Several numerical experiments, in which an oceanographic model was forced with northeasterly winds having climatological alongshore variability, were performed in order to study the influence of spatial variability in the bora wind field on the surface currents in the northern Adriatic. Numerical model results showed that during bora episodes with lower speeds and fast offshore decay surface currents along transect Rovinj - Po River are predominantly in the downwind direction. On the other hand, during bora episodes with strong intensity and slow offshore decay, a cyclonic gyre due to the pronounced bora alongshore variability is formed in the northernmost part of the Adriatic Sea and the studied transect is influenced by the counter currents. Moreover, bora having a high speed and a short offshore range produces the same effect in the eastern part of the Rovinj - Po River transect as low-speed bora characterised by slow offshore decay. Eulerian current measurements performed in the northern Adriatic during bora episodes characterised by different synoptic conditions supported the numerical model findings. Surface currents during the bora episode of 8-11 February 1984 were directed downwind, whereas during the episode of 12-19 February 1984 they were directed upwind. The first episode was characterised by a deep bora layer with cyclonic activity over the western Mediterranean and Genoa Bay, whereas the second one was accompanied by temperature inversion and a southwesterly tropospheric wind above a shallow bora layer. According to the hydraulic theory developed by Smith (1985), an observed descent of isentropes during the second bora episode led to the stronger acceleration in the bora layer and its larger offshore extent. Different offshore bora decays during studied events were confirmed by a comparison of the wind data originating from the meteorological stations positioned on the opposite

  8. Controls of Soluble Al in Experimental Acid Sulfate Conditions and Acid Sulfate Soils

    Institute of Scientific and Technical Information of China (English)

    LINCHUXIA; M.D.MELVILLE

    1997-01-01

    The controls of soluble Al concentration were examined in three situations of acid sulfate conditions:1) experimental acid sulfate conditions by addition of varying amounts of Al(OH)3(gibbsite) into a sequence of H2SO4 solutions;2)experimental acid sulfate conditions by addition of the same sequence of H2SO4 solutions into two non-cid sulfacte soil samples with known amounts of acid oxalate extractable Al; and 3) actual acid sulfate soil conditions.The experiment using gibbsite as an Al-bearing mineral showed that increase in the concentration of H2SO4 solution increased the soluble Al concentration,accompanied by a decrease i the solution pH, Increasing amount of gibbsite added to the H2SO4 solutions also increased soluble Al concentration,but resulted in an increase in solution pH.Within the H2SO4 concentration range of 0.0005-0.5mol L-1 and the Al(OH)3 range of 0.01-0.5g(in 25 mL of H2SO4 solutions),the input of H2SO4 had the major control on soluble Al Concentration and pH .The availability of Al(OH)3,however,was responsible for the spread fo the various sample points,with a tendency that the samples containing more gibbsite had a higher soluble Al concentration than those containing less gibbsite at equivalent pH levels.The experimental results from treatment of soil samples with H2SO4 solutions and the analytical results of acid sulfate soils also showed the similar trend.

  9. E-waste management challenges in Iran: presenting some strategies for improvement of current conditions.

    Science.gov (United States)

    Taghipour, Hassan; Nowrouz, Parviz; Jafarabadi, Mohamad Asghari; Nazari, Jalil; Hashemi, Ahmad Asl; Mosaferi, Mohammad; Dehghanzadeh, Reza

    2012-11-01

    E-waste is one of the fastest-growing waste streams in Iran, owing to an increase in consumption of electrical and electronic equipment. Nevertheless, as is the case in some other countries, E-waste management has not received sufficient attention. For the successful implementation of any waste management plan (including an E-waste management plan), the availability of sufficient and accurate information on the quantities and composition of the waste generated and on current management conditions is a fundamental prerequisite. At present, in Iran, there is no available and accurate information that describes the characteristics and generation rate of E-waste or the actual practice of management and handling of the waste. For this initial study, eight electronic products were selected for the determination of their E-waste generation rate in the country, and two cities, Tehran and Tabriz, were selected for assessment of the current condition of E-waste management. The study found that the amount of E-waste generation in the country for the eight selected electronic items alone was 115,286, 112,914 and 115,151 metric tons in 2008, 2009 and 2010, respectively. Of the types of electronic items included in the study, televisions, with an average of 42.42%, and PCs, with an average of 32.66% accounted for the greatest proportions of the total mass of E-waste generated during 2008-2010. Currently, despite the fact that primary legislation for E-waste management (as part of general waste legislation) exists in Iran, this primary legislation has not yet been implemented. In practical terms, there is no definite policy or plan for the allocation of funds to prepare suitable equipment and facilities for the management and recycling of E-waste at the end of the products' useful life. Proposed improvements in current conditions are identified, first by considering other countries' experiences and then suggesting specific practical policies, rules, and regulations that should be

  10. Experimental observation of dynamic ductile damage development under various triaxiality conditions

    Science.gov (United States)

    Pillon, Laurianne; Adolf, Lise-Marie

    2015-06-01

    Fracture in ductile materials finds its origin in microscopic mechanisms: the nucleation of voids that grow and coalesce in order to form a crack. The most popular of these models, proposed by Gurson, aims at describing the damage development with respect to the plastic behavior of porous material. The Gurson model has been extended by Perrin to describe damage evolution in ductile viscoplastic porous materials. The Gurson-Perrin model (GPm) allows representing damage development with respect to the stress triaxiality and strain-rate conditions. We propose a new experimental design able to test and validate the GPm under various dynamic conditions and for different triaxiality levels. The experimental project will be detailed. A notch is drawn in the Cu cylindrical target where damage develops and the local failure occurs. A variation of the notch radius enables a variation in the triaxiality level. Three notch radii have been tested. Observations with numerical cameras allow following the shape of the notch, a characteristic of damage development. Several PDV measurements have been performed around the target. A first analysis of this experimental process will be shown and comparisons with numerical simulations will be presented.

  11. Long-term experimental manipulation of moisture conditions and its impact on moss-living tardigrades

    Directory of Open Access Journals (Sweden)

    Ingemar K. JÖNSSON

    2007-09-01

    Full Text Available The effects of long-term experimentally modified hydration conditions on populations of moss-living tardigrades were investigated in a naturally dry South-Swedish alvar environment at the Island Öland. Carbonite rocks with mosses were collected from rock fences and arranged in three experimental groups: increased dehydration, increased hydration, and control. The total experimental period was 18 months, with treatments applied during two 6 month periods. The density of tardigrade populations was recorded. The total population of tardigrades, all species included, tended to be lower under watering treatment, but the difference was only marginally significant. Populations of Richtersius coronifer and Echiniscus spiniger did not respond to the treatments, while populations of Milnesium tardigradum declined under conditions of increased hydration. The density of eggs in R. coronifer was also lower in the watering treatment. Thus, no positive response to increased hydration was recorded. These results suggest that the tardigrade populations either were not limited by the amount of hydrated periods, or that some other factor(s counteracted the expected positive response to increased hydration. All populations showed a high variability in density among different moss samples, and the rock from which a sample was taken explained a significant part of this variability. This confirms a commonly believed, but seldom quantified, high heterogeneity in density of semi-terrestrial tardigrades, also among seemingly very similar substrates.

  12. Factors Influencing Adult Physical Health after Controlling for Current Health Conditions: Evidence from a British Cohort

    Science.gov (United States)

    Cheng, Helen; Furnham, Adrian

    2013-01-01

    This study explored a longitudinal data set of 6875 British adults examining the effects of parental social status (measured at birth), cognitive ability (at age 11 yrs), personality traits, education and occupational attainment on physical health and functioning (all measured at age 50 yrs), after taking account of current health conditions (number of illness). Correlation analysis showed that parental social class, childhood cognitive ability, education and occupation, and two personality traits (Emotional Stability/Neuroticism, and Conscientiousness) were all significantly associated with adult physical health variables. Structural equation modelling showed that health conditions and personality traits were significantly, and inversely, associated with physical health (indicated by good daily physical functioning, relative absence of pain, perceived health, and low level of limitations at work due to physical health). Parental social status, childhood intelligence, educational and occupational attainment were all modestly, but significantly and directly, associated with adult physical health. The effect of childhood intelligence on adult physical health was, in part, mediated through Emotional Stability and Conscientiousness. After controlling for health conditions Emotional Stability was the strongest predictor of physical health. Implications and limitations are discussed. PMID:23826090

  13. Factors influencing adult physical health after controlling for current health conditions: evidence from a british cohort.

    Directory of Open Access Journals (Sweden)

    Helen Cheng

    Full Text Available This study explored a longitudinal data set of 6875 British adults examining the effects of parental social status (measured at birth, cognitive ability (at age 11 yrs, personality traits, education and occupational attainment on physical health and functioning (all measured at age 50 yrs, after taking account of current health conditions (number of illness. Correlation analysis showed that parental social class, childhood cognitive ability, education and occupation, and two personality traits (Emotional Stability/Neuroticism, and Conscientiousness were all significantly associated with adult physical health variables. Structural equation modelling showed that health conditions and personality traits were significantly, and inversely, associated with physical health (indicated by good daily physical functioning, relative absence of pain, perceived health, and low level of limitations at work due to physical health. Parental social status, childhood intelligence, educational and occupational attainment were all modestly, but significantly and directly, associated with adult physical health. The effect of childhood intelligence on adult physical health was, in part, mediated through Emotional Stability and Conscientiousness. After controlling for health conditions Emotional Stability was the strongest predictor of physical health. Implications and limitations are discussed.

  14. Experimental study of critical heat flux enhancement with hypervapotron structure under natural circulation conditions

    Energy Technology Data Exchange (ETDEWEB)

    Hou, Fangxin [Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing (China); Chang, Huajian [Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing (China); State Nuclear Power Technology R& D Center (Beijing), Beijing (China); Zhao, Yufeng, E-mail: zhaoyufeng@snptc.com.cn [State Nuclear Power Technology R& D Center (Beijing), Beijing (China); Zhang, Ming; Gao, Tianfang [State Nuclear Power Technology R& D Center (Beijing), Beijing (China); Chen, Peipei [State Power Investment Corporation, Beijing (China)

    2017-05-15

    Highlights: • Natural circulation tests are performed to study the effect of hypervapotron on CHF. • Hypervapotron structure improves CHF under natural circulation conditions. • Visualization data illustrate vapor blanket behavior under subcooled flow conditions. - Abstract: The enhancement of critical heat flux with a hypervapotron structure under natural circulation conditions is investigated in this study. Subcooled flow boiling CHF experiments are performed using smooth and hypervapotron surfaces at different inclination angles under natural circulation conditions. The experimental facility, TESEC (Test of External Vessel Surface with Enhanced Cooling), is designed to conduct CHF experiments in a 30 mm by 61 mm rectangular flow channel with a 200 mm long heated surface along the flow direction. The two-phase flow of subcooled flow boiling on both smooth and hypervapotron heating plates is observed and analyzed by the high-speed visualization technology. The results show that both smooth surface and hypervapotron surface CHF data exhibit a similar trend against inclination angles compared with the CHF results under forced flow condition on the same facility in earlier studies. However, the CHF enhancement of the hypervapotron structure is evidently more significant than the one under forced flow conditions. The experiments also indicate that the natural flow rates are higher with hypervapotron structure. The initiation of CHF is analyzed under transient subcooling and flow rate conditions for both smooth and hypervapotron heating surfaces. An explanation is given for the significant enhancement effect caused by the hypervapotron surface under natural circulation conditions. The visualization data are exhibited to demonstrate the behavior of the vapor blanket at various inclination angles and on different surfaces. The geometric data of the vapor blanket are quantified by an image post-processing method. It is found that the thickness of the vapor blanket

  15. Experimental Simulation of Dolomite Dissolution Under Burial Diagenesis Conditions and Thermodynamic Interpretation

    Institute of Scientific and Technical Information of China (English)

    黄思静; 肖林萍; 等

    2000-01-01

    Simulating experiments on dolomite dissolution by acetic acid were made under burial diagenesis conditions,at temperatures ranging from 75℃to 130℃ and pressures from 20 MPA to 30MPa,The results show that the dissolution rate of dolomite increased rapidly with increasing temperature and prssure,From 75℃/Mpa to 130℃/30 MPa,the total amount of released ca and Mg increased from 32.98mg/L to 337.9mg/L,over one order of magnitude in difference,Thermodynamic calculation indicates that the increment of Gibbs free energy (ΔG) of the chemical reaction decreases with increasing temperature and pressure.This thermodynamic result is consistent with the experimental result.Based on the Experimental results.it is suggested that secondary prosities formed by dolomite dissolution under conditions of deep burial diagenesis should be more common than those under epigenesis and shallow burial conditions,and therefore dolomite reservoires in the formations that have been deeply buried should be more abundant than in the formations that have only been shallowly buried.

  16. Experimental Aspects in the Vibration-Based Condition Monitoring of Large Hydrogenerators

    Directory of Open Access Journals (Sweden)

    Geraldo Carvalho Brito Junior

    2017-01-01

    Full Text Available Based on experimental observations on a set of twenty 700 MW hydrogenerators, compiled from several technical reports issued over the last three decades and collected from the reprocessing of the vibration signals recorded during the last commissioning tests, this paper shows that the accurate determination of the journal bearings operating conditions may be a difficult task. It shows that the outsize bearing brackets of large hydrogenerators are subject to substantial dimensional changes caused by external agents, like the generator electromagnetic field and the bearing cooling water temperature. It also shows that the shaft eccentricity of a journal bearing of a healthy large hydrogenerator, operating in steady-state condition, may experience unpredictable, sudden, and significant changes without apparent reasons. Some of these phenomena are reproduced in ordinary commissioning tests or may be noticed even during normal operation, while others are rarely observed or are only detected through special tests. These phenomena modify journal bearings stiffness and damping, changing the hydrogenerator dynamics, creating discrepancies between theoretical predictions and experimental measurements, and making damage detection and diagnostics difficult. Therefore, these phenomena must be analyzed and considered in the application of vibration-based condition monitoring to these rotating machines.

  17. Pliocene Model Intercomparison Project (PlioMIP): experimental design and boundary conditions (Experiment 2)

    Science.gov (United States)

    Haywood, A.M.; Dowsett, H.J.; Robinson, M.M.; Stoll, D.K.; Dolan, A.M.; Lunt, D.J.; Otto-Bliesner, B.; Chandler, M.A.

    2011-01-01

    The Palaeoclimate Modelling Intercomparison Project has expanded to include a model intercomparison for the mid-Pliocene warm period (3.29 to 2.97 million yr ago). This project is referred to as PlioMIP (the Pliocene Model Intercomparison Project). Two experiments have been agreed upon and together compose the initial phase of PlioMIP. The first (Experiment 1) is being performed with atmosphere-only climate models. The second (Experiment 2) utilises fully coupled ocean-atmosphere climate models. Following on from the publication of the experimental design and boundary conditions for Experiment 1 in Geoscientific Model Development, this paper provides the necessary description of differences and/or additions to the experimental design for Experiment 2.

  18. Pliocene Model Intercomparison Project (PlioMIP): Experimental Design and Boundary Conditions (Experiment 2)

    Science.gov (United States)

    Haywood, A. M.; Dowsett, H. J.; Robinson, M. M.; Stoll, D. K.; Dolan, A. M.; Lunt, D. J.; Otto-Bliesner, B.; Chandler, M. A.

    2011-01-01

    The Palaeoclimate Modelling Intercomparison Project has expanded to include a model intercomparison for the mid-Pliocene warm period (3.29 to 2.97 million yr ago). This project is referred to as PlioMIP (the Pliocene Model Intercomparison Project). Two experiments have been agreed upon and together compose the initial phase of PlioMIP. The first (Experiment 1) is being performed with atmosphere only climate models. The second (Experiment 2) utilizes fully coupled ocean-atmosphere climate models. Following on from the publication of the experimental design and boundary conditions for Experiment 1 in Geoscientific Model Development, this paper provides the necessary description of differences and/or additions to the experimental design for Experiment 2.

  19. Experimental Adiabatic Quantum Factorization under Ambient Conditions Based on a Solid-State Single Spin System.

    Science.gov (United States)

    Xu, Kebiao; Xie, Tianyu; Li, Zhaokai; Xu, Xiangkun; Wang, Mengqi; Ye, Xiangyu; Kong, Fei; Geng, Jianpei; Duan, Changkui; Shi, Fazhan; Du, Jiangfeng

    2017-03-31

    The adiabatic quantum computation is a universal and robust method of quantum computing. In this architecture, the problem can be solved by adiabatically evolving the quantum processor from the ground state of a simple initial Hamiltonian to that of a final one, which encodes the solution of the problem. Adiabatic quantum computation has been proved to be a compatible candidate for scalable quantum computation. In this Letter, we report on the experimental realization of an adiabatic quantum algorithm on a single solid spin system under ambient conditions. All elements of adiabatic quantum computation, including initial state preparation, adiabatic evolution (simulated by optimal control), and final state read-out, are realized experimentally. As an example, we found the ground state of the problem Hamiltonian S_{z}I_{z} on our adiabatic quantum processor, which can be mapped to the factorization of 35 into its prime factors 5 and 7.

  20. Quantitative study on propagation and healing of Airy beams under experimental conditions.

    Science.gov (United States)

    Zhuang, Fei; Zhu, Ziyi; Margiewicz, Jessica; Shi, Zhimin

    2015-03-01

    We investigate the propagation and healing of Airy beams in two dimensions that are obtainable under practical experimental conditions. We introduce an intensity similarity factor to quantitatively describe how an Airy beam retains its original shape. Based on such a figure of merit, we define a shape-retaining distance to quantify how far an Airy beam can keep the shape of its main lobe upon propagation and a healing distance to quantify how soon an initially partially blocked Airy beam can restore its main lobe profile. We perform an analysis on how these two distances scale with experimental parameters. We further use an interference picture to interpret the healing phenomenon of an Airy beam. Our work can serve as a guideline for quantitative performance analysis for applications of Airy beams and can be extended to other special beams in a straightforward fashion.

  1. Experimental Investigation into Suitable Process Conditions for Plastic Injection Molding of Thin-Sheet Parts

    Directory of Open Access Journals (Sweden)

    Dyi-Cheng Chen

    2014-04-01

    Full Text Available This study performs an experimental investigation into the effects of the process parameters on the surface quality of injection molded thin-sheet thermoplastic components. The investigations focus specifically on the shape, number and position of the mold gates, the injection pressure and the injection rate. It can be seen that the gravity force entering point improved filling of the cavity for the same forming time and injection pressure. Moreover, it shows the same injection pressure and packing time, the taper-shape gate yields a better surface appearance than the sheet-shape gate. The experimental results provide a useful source of reference in suitable the process conditions for the injection molding of thin-sheet plastic components.

  2. Deep Boreholes Seals Subjected to High P, T conditions – Preliminary Experimental Studies

    Energy Technology Data Exchange (ETDEWEB)

    Caporuscio, Florie Andre [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Norskog, Katherine Elizabeth [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Maner, James Lavada [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-01-18

    The objective of this planned experimental work is to evaluate physio-chemical processes for ‘seal’ components and materials relevant to deep borehole disposal. These evaluations will encompass multi-laboratory efforts for the development of seals concepts and application of Thermal-Mechanical-Chemical (TMC) modeling work to assess barrier material interactions with subsurface fluids, their stability at high temperatures, and the implications of these processes to the evaluation of thermal limits. Deep borehole experimental work will constrain the Pressure, Temperature (P, T) conditions which “seal” material will experience in deep borehole crystalline rock repositories. The rocks of interest to this study include the silicic (granitic gneiss) end members. The experiments will systematically add components to capture discrete changes in both water and EBS component chemistries.

  3. Knock-in model of Dravet syndrome reveals a constitutive and conditional reduction in sodium current.

    Science.gov (United States)

    Schutte, Ryan J; Schutte, Soleil S; Algara, Jacqueline; Barragan, Eden V; Gilligan, Jeff; Staber, Cynthia; Savva, Yiannis A; Smith, Martin A; Reenan, Robert; O'Dowd, Diane K

    2014-08-15

    Hundreds of mutations in the SCN1A sodium channel gene confer a wide spectrum of epileptic disorders, requiring efficient model systems to study cellular mechanisms and identify potential therapeutic targets. We recently demonstrated that Drosophila knock-in flies carrying the K1270T SCN1A mutation known to cause a form of genetic epilepsy with febrile seizures plus (GEFS+) exhibit a heat-induced increase in sodium current activity and seizure phenotype. To determine whether different SCN1A mutations cause distinct phenotypes in Drosophila as they do in humans, this study focuses on a knock-in line carrying a mutation that causes a more severe seizure disorder termed Dravet syndrome (DS). Introduction of the DS SCN1A mutation (S1231R) into the Drosophila sodium channel gene para results in flies that exhibit spontaneous and heat-induced seizures with distinct characteristics and lower onset temperature than the GEFS+ flies. Electrophysiological studies of GABAergic interneurons in the brains of adult DS flies reveal, for the first time in an in vivo model system, that a missense DS mutation causes a constitutive and conditional reduction in sodium current activity and repetitive firing. In addition, feeding with the serotonin precursor 5-HTP suppresses heat-induced seizures in DS but not GEFS+ flies. The distinct alterations of sodium currents in DS and GEFS+ GABAergic interneurons demonstrate that both loss- and gain-of-function alterations in sodium currents are capable of causing reduced repetitive firing and seizure phenotypes. The mutation-specific effects of 5-HTP on heat-induced seizures suggest the serotonin pathway as a potential therapeutic target for DS.

  4. Quantum heat current under non-perturbative and non-Markovian conditions: Applications to heat machines

    Science.gov (United States)

    Kato, Akihito; Tanimura, Yoshitaka

    2016-12-01

    We consider a quantum system strongly coupled to multiple heat baths at different temperatures. Quantum heat transport phenomena in this system are investigated using two definitions of the heat current: one in terms of the system energy and the other in terms of the bath energy. When we consider correlations among system-bath interactions (CASBIs)—which have a purely quantum mechanical origin—the definition in terms of the bath energy becomes different. We found that CASBIs are necessary to maintain the consistency of the heat current with thermodynamic laws in the case of strong system-bath coupling. However, within the context of the quantum master equation approach, both of these definitions are identical. Through a numerical investigation, we demonstrate this point for a non-equilibrium spin-boson model and a three-level heat engine model using the reduced hierarchal equations of motion approach under the strongly coupled and non-Markovian conditions. We observe the cyclic behavior of the heat currents and the work performed by the heat engine, and we find that their phases depend on the system-bath coupling strength. Through consideration of the bath heat current, we show that the efficiency of the heat engine decreases as the strength of the system-bath coupling increases, due to the CASBI contribution. In the case of a large system-bath coupling, the efficiency decreases further if the bath temperature is increased, even if the ratio of the bath temperatures is fixed, due to the discretized nature of energy eigenstates. This is also considered to be a unique feature of quantum heat engines.

  5. Echolalic responses by a child with autism to four experimental conditions of sociolinguistic input.

    Science.gov (United States)

    Violette, J; Swisher, L

    1992-02-01

    Studies of the immediate verbal imitations (IVIs) of subjects with echolalia report that features of linguistic or social input alone affect the number of IVIs elicited. This experimental study of a child with echolalia and autism controlled each of these variables while introducing a systematic change in the other. The subject produced more (p less than .05) IVIs in response to unknown lexical words presented with a high degree of directiveness (Condition D) than in response to three other conditions of stimulus presentation (e.g., unknown lexical words, minimally directive style.) Thus, an interaction between the effects of linguistic and social input was demonstrated. IVIs were produced across all conditions, primarily during first presentations of lexical stimuli. Only the IVIs elicited by first presentations of the lexical stimuli during Condition D differed significantly (p less than .05) from the number of IVIs elicited by first presentations of lexical stimuli in other conditions. These findings viewed together suggest that the occurrence of IVIs was related, at least for this child, to an uncertain or informative event and that this response was significantly greater when the lexical stimuli were unknown and presented in a highly directive style.

  6. Experimental study of two-phase flows under reduced gravity conditions

    Energy Technology Data Exchange (ETDEWEB)

    Roy, T., E-mail: tirthankar.roy@ntnu.no [Purdue Univ., West Lafayette, Indiana (United States); Norwegian Univ. of Science and Tech., Trondheim (Norway); Liu, Y.; Chen, S.-W.; Hibiki, T.; Ishii, M., E-mail: liu130@purdue.edu, E-mail: hibiki@purdue.edu, E-mail: ishii@purdue.edu [Purdue Univ., West Lafayette, Indiana (United States); Duval, W., E-mail: walter.m.duval@nasa.gov [NASA Glenn Research Center, Cleveland, Ohio (United States)

    2011-07-01

    Study of gas-liquid two-phase flows under reduced gravity conditions is very important for space applications such as active thermal control systems. Two-fluid model along with Interfacial Area Transport Equation (IATE) is a useful tool available to dynamically predict the behavior of such two-phase flows under normal and reduced gravity conditions. As part of a big program experiments were carried out in a 304 mm inner diameter test facility on earth to generate a detailed experimental data base which is required for the evaluation of two-fluid model along with IATE under reduced gravity conditions. In the present case reduced gravity condition is simulated using two-liquids of similar densities. Such a large diameter test section was chosen to study the development of drops to their full. Twelve flow conditions were chosen around predicted bubbly flow to cap-bubbly flow transition region. Detailed local data was obtained at ten radial locations for each of three axial locations using double-sensor conductivity probes. Some of the results are presented here and discussed. (author)

  7. An experimental study on counter current flow limitation in annular narrow gaps with large diameter

    Energy Technology Data Exchange (ETDEWEB)

    Park, Rae Joon; Jeong, Ji Whan; Lee, Sung Jin; Cho, Young Ro; Ha, Kwang Sun; Kim, Sang Baik; Kim, Hee Dong [Korea Atomic Energy Research Institute, Taejeon (Korea)

    2002-04-01

    The present study intends to carry out CCFL experiment with the same gap size as the CHFG facility and suggest an empirical correlation in order to provide basic information useful to development of an empirical critical-power correlation. The present facility consists of water accumulator tank, test section, DC pump, air regulator, valves and sensors. Air and water are used as working fluids. The experiments are carried out at the atmospheric pressure. Differential pressure between the gap ends, liquid and gas phase flow rates, temperature, lower plenum pressure are measured.Measured values are expressed in terms of Wallis' parameter using gap size as a characteristic length. There is a big difference between the present experimental results and the Koizumi et al.'s results, but the present experimental results are very similar to the Richter et al.'s results. The present results agree well with the Osakabe and Kawasaki's results. In comparison of present experiments with the Koizumi et al.'s experiments, gap thickness is similar, but the diameter of the present is bigger than that of Koizumi et al.'s experiments. In comparison of present experiments with the Richter et al.'s experiments, diameter is similar, but the gap thickness of the present is smaller than that of Richter et al.'s experiments. It is judged from these results that correlation development on CCFL to consider gap thickness is reasonable at similar condition of diameter.The developed correlation will be used to develop the CHFG model. 36 refs., 26 figs., 7 tabs. (Author)

  8. Deep Boreholes Seals Subjected to High P,T conditions - Proposed Experimental Studies

    Science.gov (United States)

    Caporuscio, F.

    2015-12-01

    Deep borehole experimental work will constrain the P,T conditions which "seal" material will experience in deep borehole crystalline rock repositories. The rocks of interest to this study include mafic (amphibolites) and silicic (granitic gneiss) end members. The experiments will systematically add components to capture discrete changes in both water and EBS component chemistries. Experiments in the system wall rock-clay-concrete-groundwater will evaluate interactions among components, including: mineral phase stability, metal corrosion rates and thermal limits. Based on engineered barrier studies, experimental investigations will move forward with three focusses. First, evaluation of interaction between "seal" materials and repository wall rock (crystalline) under fluid-saturated conditions over long-term (i.e., six-month) experiments; which reproduces the thermal pulse event of a repository. Second, perform experiments to determine the stability of zeolite minerals (analcime-wairakitess) under repository conditions. Both sets of experiments are critically important for understanding mineral paragenesis (zeolites and/or clay transformations) associated with "seals" in contact with wall rock at elevated temperatures. Third, mineral growth at the metal interface is a principal control on the survivability (i.e. corrosion) of waste canisters in a repository. The objective of this planned experimental work is to evaluate physio-chemical processes for 'seal' components and materials relevant to deep borehole disposal. These evaluations will encompass multi-laboratory efforts for the development of seals concepts and application of Thermal-Mechanical-Chemical (TMC) modeling work to assess barrier material interactions with subsurface fluids and other barrier materials, their stability at high temperatures, and the implications of these processes to the evaluation of thermal limits.

  9. Experimental study of movements respiratory conditions acceptable in radiotherapy techniques advanced; Estudio experimental de las condiciones de movimiento respiratorio aceptables en tecnicas de radioterapia avanzada

    Energy Technology Data Exchange (ETDEWEB)

    Carrasco de Fez, P.; Ruiz Martinez, A.; Ruiz Martinez, A.; Jornet Sala, N.; Latorre Musoll, A.; Eudaldo Puell, T.; Ribas Morales, M.

    2015-07-01

    The aim is Determine experimentally in what conditions the movement of the PTV produces uncertainties unacceptable in the various stages of the treatment radiotherapy, from the acquisition of imagens 4D to the irradiation. (Author)

  10. Experimental setup for rapid crystallization using favoured chemical potential and hydrodynamic conditions

    Indian Academy of Sciences (India)

    V K Dixit; B V Rodrigues; H L Bhat

    2001-10-01

    The rapid crystallization of KH2PO4 (KDP) from solution is demonstrated at a rate up to ≈7.5 mm/day along [100] and 22 mm/day along [001] in a crystallizer of 5 l capacity, using accelerated crucible rotation technique (ACRT) and simulated platform geometry for controlling the hydrodynamic conditions. On an experimental basis we have grown the crystals up to 40 × 43 × 66 mm3 size in about 3 days. Comparative analysis of the main structural and optical properties of crystals grown by conventional and rapid crystallization technique, is discussed.

  11. Experimental investigation on the causes for pellet fragmentation under LOCA conditions

    Energy Technology Data Exchange (ETDEWEB)

    Bianco, Andrea

    2015-07-23

    An experimental investigation was conducted in hot cells on single fuel rod segments to appraise the behavior of fuel pellets fragmentation during a loss of coolant accident in a light water reactor. In pursuing the conceptual design of the experiment, calculations were performed to study the thermal-hydraulics boundary conditions and the fuel rod behavior during the transient. The experiment's results encompass non-destructive and destructive examinations. In order to describe the resulting fuel fragments size distribution, a semi-empirical correlation was derived from the fractal theory.

  12. A Review & Assessment of Current Operating Conditions Allowable Stresses in ASME Section III Subsection NH

    Energy Technology Data Exchange (ETDEWEB)

    R. W. Swindeman

    2009-12-14

    The current operating condition allowable stresses provided in ASME Section III, Subsection NH were reviewed for consistency with the criteria used to establish the stress allowables and with the allowable stresses provided in ASME Section II, Part D. It was found that the S{sub o} values in ASME III-NH were consistent with the S values in ASME IID for the five materials of interest. However, it was found that 0.80 S{sub r} was less than S{sub o} for some temperatures for four of the materials. Only values for alloy 800H appeared to be consistent with the criteria on which S{sub o} values are established. With the intent of undertaking a more detailed evaluation of issues related to the allowable stresses in ASME III-NH, the availabilities of databases for the five materials were reviewed and augmented databases were assembled.

  13. Environmental impacts of barley cultivation under current and future climatic conditions

    DEFF Research Database (Denmark)

    Dijkman, Teunis Johannes; Birkved, Morten; Saxe, Henrik

    2017-01-01

    The purpose of this work is to compare the environmental impacts of spring barley cultivation in Denmark under current (year 2010) and future (year 2050) climatic conditions. Therefore, a Life Cycle Assessment was carried out for the production of 1 kg of spring barley in Denmark, at farm gate......-products, the resulting environmental impacts were allocated between the main product and their respective by-products using economic allocation. Impact assessment was done using the ReCiPe (H) methodology, except for toxicity impacts, which were assessed using USEtox. The results show that the impacts for all impact...... for the increased impacts. This finding was confirmed by the sensitivity analysis. Because this study focused solely on the impacts of climate change, technological improvements and political measures to reduce impacts in the 2050 scenario are not taken into account. Options to mitigate the environmental impacts...

  14. Current Fluctuations of the One Dimensional Symmetric Simple Exclusion Process with Step Initial Condition

    Science.gov (United States)

    Derrida, Bernard; Gerschenfeld, Antoine

    2009-07-01

    For the symmetric simple exclusion process on an infinite line, we calculate exactly the fluctuations of the integrated current Q t during time t through the origin when, in the initial condition, the sites are occupied with density ρ a on the negative axis and with density ρ b on the positive axis. All the cumulants of Q t grow like sqrt{t} . In the range where Qt˜ sqrt{t} , the decay exp [- Q {/t 3}/ t] of the distribution of Q t is non-Gaussian. Our results are obtained using the Bethe ansatz and several identities derived recently by Tracy and Widom for exclusion processes on the infinite line.

  15. Exploration of Experimental Data On Atrazine Degradation In Relation To Environmental Conditions

    Science.gov (United States)

    Putters, B.

    The objective of this project is to find the soil factors which dominate the degradation behaviour of atrazine (pesticide). From published experiments on atrazine degradation in the subsurface, the available data concerning soil characteristics, experimental conditions, and the measured degra- dation rates were put into a database. From literature, environmental conditions could be related to degradation rates. These relationships were tested by exploration of the dataset by statistical techniques. In general, the degradation is mainly determined by the availability of the substrate (atrazine) and the biological activity. More specific re- lationships could be derived from the dataset and will be presented at the conference. The relationships can also be used for degradation rate estimates for modelling pur- poses.

  16. Influence of Experimental Conditions on Electronic Tongue Results—Case of Valsartan Minitablets Dissolution

    Directory of Open Access Journals (Sweden)

    Małgorzata Wesoły

    2016-08-01

    Full Text Available A potentiometric electronic tongue was applied to study the release of valsartan from pharmaceutical formulations, i.e., minitablets uncoated and coated with Eudragit E. Special attention was paid to evaluate the influence of medium temperature and composition, as well as to compare the performances of the sensor arrays working in various hydrodynamic conditions. The drug dissolution profiles registered with the ion-sensitive electrodes were compared with standard dissolution tests performed with USP Apparatus 2 (paddle. Moreover, the signal changes of all sensors were processed by principal component analysis to visualize the release modifications, related to the presence of the coating agent. Finally, the importance and influence of the experimental conditions on the results obtained using potentiometric sensor arrays were discussed.

  17. Experimental investigation of the noise emission of axial fans under distorted inflow conditions

    Science.gov (United States)

    Zenger, Florian J.; Renz, Andreas; Becher, Marcus; Becker, Stefan

    2016-11-01

    An experimental investigation on the noise emission of axial fans under distorted inflow conditions was conducted. Three fans with forward-skewed fan blades and three fans with backward-skewed fan blades and a common operating point were designed with a 2D element blade method. Two approaches were adopted to modify the inflow conditions: first, the inflow turbulence intensity was increased by two different rectangular grids and second, the inflow velocity profile was changed to an asymmetric characteristic by two grids with a distinct bar stacking. An increase in the inflow turbulence intensity affects both tonal and broadband noise, whereas a non-uniform velocity profile at the inlet influences mainly tonal components. The magnitude of this effect is not the same for all fans but is dependent on the blade skew. The impact is greater for the forward-skewed fans than for the backward-skewed and thus directly linked to the fan blade geometry.

  18. Experimental Investigation of Mechanical Properties of PVC Polymer under Different Heating and Cooling Conditions

    Directory of Open Access Journals (Sweden)

    Sarkawt Rostam

    2016-01-01

    Full Text Available Due to a widely increasing usage of polymers in various industrial applications, there should be a continuous need in doing research investigations for better understanding of their properties. These applications require the usage of the polymer in different working environments subjecting the material to various temperature ranges. In this paper, an experimental investigation of mechanical properties of polyvinyl chloride (PVC polymer under heating and cooling conditions is presented. For this purpose standard samples are prepared and tested in laboratory using universal material testing apparatus. The samples are tested under different conditions including the room temperature environment, cooling in a refrigerator, and heating at different heating temperatures. It is observed that the strength of the tested samples decreases with the increasing of heating temperature and accordingly the material becomes softer. Meanwhile the cooling environments give a clear increasing to the strength of the material.

  19. Experimental Evaluation of the Surface Alteration of Gasket Samples under Operative Conditions

    Directory of Open Access Journals (Sweden)

    M.C. Bignozzi

    2015-12-01

    Full Text Available This paper investigates the surface alteration of gasket samples commercialized by two alternative producers. These gaskets, in polymeric materials, are installed in process plants used for cleaning tires molds by a pioneering ultrasonic process. They are exposed to a combination of ultrasonic waves, temperature, humidity and acid attack causing several erosion phenomena. Their surface degradation under ordinary operative conditions was investigated using mechanical and tribological tests. The experimental characterization was performed by optical microscopy, scanning electron microscopy, thermograms, differential scanning calorimetry curves and infrared spectra aiming at defining the specific mechanics of wearing. As a conclusion, it was possible to state that even if samples exhibit similar chemical structures, their thermal and mechanical properties as well as their geometric dimensions are different. Such differences in the materials might cause various unexpected wear behaviors when gaskets are employed in the same working conditions.


  20. Current Parental Depression and Offspring Perceived Self-Competence: A Quasi-Experimental Examination

    Science.gov (United States)

    Class, Quetzal A.; D’Onofrio, Brian M.; Singh, Amber L.; Ganiban, Jody M.; Spotts, E. L.; Lichtenstein, Paul; Reiss, David; Neiderhiser, Jenae M.

    2013-01-01

    A genetically-informed, quasi-experimental design was used to examine the genetic and environmental processes underlying associations between current parental depressive symptoms and offspring perceived self-competence. Participants, drawn from a population-based Swedish sample, were 852 twin pairs and their male (52%) and female offspring aged 15.7 ± 2.4 years. Parental depressive symptoms were measured using the Center for Epidemiological Studies Depression scale. Offspring perceived self-competence was measured using a modified Harter Perceived Competence Scale. Cousin comparisons and Children of Twins (CoT) designs suggested that associations between maternal depressive symptoms and offspring perceived self-competence were due to shared genetic/environmental liability. The mechanism responsible for father-offspring associations, however, was independent of genetic factors and of extended-family environmental factors, supporting a causal inference. Thus, mothers and fathers may impact offspring perceived self-competence via different mechanisms and unmeasured genetic and environmental selection factors must be considered when studying the intergenerational transmission of cognitive vulnerabilities for depression. PMID:22692226

  1. Comparison of experimental and theoretical gain-current relations in GaInP quantum well lasers

    Energy Technology Data Exchange (ETDEWEB)

    Smowton, P.M.; Chow, W.W.; Blood, P.

    2000-01-10

    The authors compare the results of a microscopic laser theory with gain and recombination currents obtained from experimental spontaneous emission spectra. The calculated absorption spectrum is first matched to that measured on a laser, ensuring that the quasi-Fermi levels for the calculation and the experiment (spontaneous emission and gain) are directly related. This allows one to determine the inhomogeneous broadening in their experimental samples. The only other inputs to the theory are literature values of the bulk material parameter. The authors then estimate the non-radiative recombination current associated with the well and wave-guide core from a comparison of measured and calculated recombination currents.

  2. Sarcopenia: An Undiagnosed Condition in Older Adults. Current Consensus Definition: Prevalence, Etiology, and Consequences

    Science.gov (United States)

    2012-01-01

    Sarcopenia, the age associated loss of skeletal muscle mass and function, has considerable societal consequences for the development of frailty, disability and health care planning. A group of geriatricians and scientists from academia and industry met in Rome, Italy on November 18, 2009 to arrive at a consensus definition of sarcopenia. The current consensus definition was approved unanimously by the meeting participants and is as follows: Sarcopenia is defined as the age-associated loss of skeletal muscle mass and function. The causes of sarcopenia are multi-factorial and can include disuse, altered endocrine function, chronic diseases, inflammation, insulin resistance, and nutritional deficiencies. While cachexia may be a component of sarcopenia, the two conditions are not the same. The diagnosis of sarcopenia should be considered in all older patients who present with observed declines in physical function, strength, or overall health. Sarcopenia should specifically be considered in patients who are bedridden, cannot independently rise from a chair, or who have a measured gait speed less that 1.0 m·s−1. Patients who meet these criteria should further undergo body composition assessment using dual energy x-ray absorptiometry (DXA) with sarcopenia being defined using currently validated definitions. A diagnosis of sarcopenia is consistent with a gait speed of less than 1 m·s−1 and an objectively measured low muscle mass (eg: appendicular mass relative to ht2 that is ≤ 7.23 kg/ m2 in men ≤ 5.67 kg/ m2 in men). Sarcopenia is a highly prevalent condition in older persons that leads to disability, hospitalization and death. PMID:21527165

  3. Condition-dependent strategies of eggshell pigmentation: an experimental study of Japanese quail (Coturnix coturnix japonica).

    Science.gov (United States)

    Duval, Camille; Cassey, Phillip; Miksík, Ivan; Reynolds, S James; Spencer, Karen A

    2013-02-15

    A relationship has been suggested between eggshell colour and female body condition based on the opposing antioxidant properties of the two main eggshell pigments: the antioxidant biliverdin (blue-green) and the pro-oxidant protoporphyrin (brown). We hypothesized that experimentally food-restricted females with low antioxidant capacity would deposit more protoporphyrin and less biliverdin in their eggshells, resulting in eggshells of reduced brightness but increased colour intensity. Two eggs were collected at the beginning and two at the end of a 2 week period from each of 24 female Japanese quails that were either food restricted or receiving ad libitum food (i.e. controls) during that time. Reflectance spectra were recorded and analysed using spectral shape descriptors, chromatic and achromatic contrasts were computed accounting for avian visual sensitivities, and eggshell pigments were quantified. We examined both spot and background pigmentation and found no significant effect of food restriction on eggshell reflectance. However, food-restricted females in lower body condition increased the deposition of protoporphyrin and decreased the amount of biliverdin invested in their eggshells. We hypothesize that in species laying brown-spotted eggshells, females modulate eggshell pigment investment in response to their body condition. According to this hypothesis, we predict that females maintain eggshell colour to limit visible changes that could be detected by predators and thereby conceal their eggs, although this work has yet to be conducted. We suggest that further experimental work on egg camouflage under different environmental conditions will elaborate on the process of pigment deposition and the physiological costs to females of laying heavily pigmented eggshells.

  4. Social life and sanitary risks: evolutionary and current ecological conditions determine waste management in leaf-cutting ants

    Science.gov (United States)

    Farji-Brener, Alejandro G.; Elizalde, Luciana; Amador-Vargas, Sabrina

    2016-01-01

    Adequate waste management is vital for the success of social life, because waste accumulation increases sanitary risks in dense societies. We explored why different leaf-cutting ants (LCA) species locate their waste in internal nest chambers or external piles, including ecological context and accounting for phylogenetic relations. We propose that waste location depends on whether the environmental conditions enhance or reduce the risk of infection. We obtained the geographical range, habitat and refuse location of LCA from published literature, and experimentally determined whether pathogens on ant waste survived to the high soil temperatures typical of xeric habitats. The habitat of the LCA determined waste location after phylogenetic correction: species with external waste piles mainly occur in xeric environments, whereas those with internal waste chambers mainly inhabit more humid habitats. The ancestral reconstruction suggests that dumping waste externally is less derived than digging waste nest chambers. Empirical results showed that high soil surface temperatures reduce pathogen prevalence from LCA waste. We proposed that LCA living in environments unfavourable for pathogens (i.e. xeric habitats) avoid digging costs by dumping the refuse above ground. Conversely, in environments suitable for pathogens, LCA species prevent the spread of diseases by storing waste underground, presumably, a behaviour that contributed to the colonization of humid habitats. These results highlight the adaptation of organisms to the hygienic challenges of social living, and illustrate how sanitary behaviours can result from a combination of evolutionary history and current environmental conditions. PMID:27226469

  5. Experimental and Empirical Time to Corrosion of Reinforced Concrete Structures under Different Curing Conditions

    Directory of Open Access Journals (Sweden)

    Ahmed A. Abouhussien

    2014-01-01

    Full Text Available Reinforced concrete structures, especially those in marine environments, are commonly subjected to high concentrations of chlorides, which eventually leads to corrosion of the embedded reinforcing steel. The total time to corrosion of such structures may be divided into three stages: corrosion initiation, cracking, and damage periods. This paper evaluates, both empirically and experimentally, the expected time to corrosion of reinforced concrete structures. The tested reinforced concrete samples were subjected to ten alternative curing techniques, including hot, cold, and normal temperatures, prior to testing. The corrosion initiation, cracking, and damage periods in this investigation were experimentally monitored by an accelerated corrosion test performed on reinforced concrete samples. Alternatively, the corrosion initiation time for counterpart samples was empirically predicted using Fick’s second law of diffusion for comparison. The results showed that the corrosion initiation periods obtained experimentally were comparable to those obtained empirically. The corrosion initiation was found to occur at the first jump of the current measurement in the accelerated corrosion test which matched the half-cell potential reading of around −350 mV.

  6. Bifurcation boundary conditions for current programmed PWM DC-DC converters at light loading

    Science.gov (United States)

    Fang, Chung-Chieh

    2012-10-01

    Three types of bifurcations (instabilities) in the PWM DC-DC converter at light loading under current mode control in continuous-conduction mode (CCM) or discontinuous-conduction mode (DCM) are analysed: saddle-node bifurcation (SNB) in CCM or DCM, border-collision bifurcation during the CCM-DCM transition, and period-doubling bifurcation in CCM. Different bifurcations occur in some particular loading ranges. Bifurcation boundary conditions separating stable regions from unstable regions in the parametric space are derived. A new methodology to analyse the SNB in the buck converter based on the peak inductor current is proposed. The same methodology is applied to analyse the other types of bifurcations and converters. In the buck converter, multiple stable/unstable CCM/DCM steady-state solutions may coexist. Possibility of multiple solutions deserves careful study, because an ignored solution may merge with a desired stable solution and make both disappear. Understanding of SNB can explain some sudden disappearances or jumps of steady-state solutions observed in switching converters.

  7. A global map of suitability for coastal Vibrio cholerae under current and future climate conditions.

    Science.gov (United States)

    Escobar, Luis E; Ryan, Sadie J; Stewart-Ibarra, Anna M; Finkelstein, Julia L; King, Christine A; Qiao, Huijie; Polhemus, Mark E

    2015-09-01

    Vibrio cholerae is a globally distributed water-borne pathogen that causes severe diarrheal disease and mortality, with current outbreaks as part of the seventh pandemic. Further understanding of the role of environmental factors in potential pathogen distribution and corresponding V. cholerae disease transmission over time and space is urgently needed to target surveillance of cholera and other climate and water-sensitive diseases. We used an ecological niche model (ENM) to identify environmental variables associated with V. cholerae presence in marine environments, to project a global model of V. cholerae distribution in ocean waters under current and future climate scenarios. We generated an ENM using published reports of V. cholerae in seawater and freely available remotely sensed imagery. Models indicated that factors associated with V. cholerae presence included chlorophyll-a, pH, and sea surface temperature (SST), with chlorophyll-a demonstrating the greatest explanatory power from variables selected for model calibration. We identified specific geographic areas for potential V. cholerae distribution. Coastal Bangladesh, where cholera is endemic, was found to be environmentally similar to coastal areas in Latin America. In a conservative climate change scenario, we observed a predicted increase in areas with environmental conditions suitable for V. cholerae. Findings highlight the potential for vulnerability maps to inform cholera surveillance, early warning systems, and disease prevention and control.

  8. [Regeneration of endocrine gastroenteropancreatic system in experimental and clinical pathology: concept development and current problems].

    Science.gov (United States)

    Ivanova, V F

    2013-01-01

    Literature review contains the literature data and the results of author's own investigations describing the coming into being and the development of the concepts on the regeneration of endocrine gastroenteropancreatic (GEP) system under the conditions of norm, experimental and clinical pathology. Data analysis permitted to reveal the similarities and differences in the course of this process in various organs of the digestive system. Endocrine GEP system renewal occurs at different levels of its organization. At the tissue level, the endocrine cells renewal occurs via the transformation of exocrine cells into the endocrine ones and as a result of differentiation from stem cells via the "agranular" cell stage which are precursors of the endocrine cells. This pathway of regeneration is the major one after the damage. Regeneration at cellular level occurs through mitotic division of the differentiated endocrine cells (early stage of regeneration) and as a result of the formation granules with different hormonal profile in D-cells. At the intracellular level, the regeneration is realized through the intracellular structure restoration after their damage induced by the increase of cell functional activity accompanied by degranulation and dystrophic changes development

  9. Experimental Study on Intelligent Control Scheme for Fan Coil Air-Conditioning System

    Directory of Open Access Journals (Sweden)

    Yanfeng Li

    2013-01-01

    Full Text Available An intelligent control scheme for fan coil air-conditioning systems has been put forward in order to overcome the shortcomings of the traditional proportion-integral-derivative (PID control scheme. These shortcomings include the inability of anti-interference and large inertia. An intelligent control test rig of fan coil air-conditioning system has been built, and MATLAB/Simulink dynamics simulation software has been adopted to implement the intelligent control scheme. A software for data exchange has been developed to combine the intelligence control system and the building automation (BA system. Experimental tests have been conducted to investigate the effectiveness of different control schemes including the traditional PID control, fuzzy control, and fuzzy-PID control for fan coil air-conditioning system. The effects of control schemes have been compared and analyzed in robustness, static and dynamic character, and economy. The results have shown that the developed data exchange interface software can induce the intelligent control scheme of the BA system more effectively. Among the proposed control strategies, fuzzy-PID control scheme which has the advantages of both traditional PID and fuzzy schemes is the optimal control scheme for the fan coil air-conditioning system.

  10. Simulation of VSPT Experimental Cascade Under High and Low Free-Stream Turbulence Conditions

    Science.gov (United States)

    Ameri, Ali A.; Giel, Paul W.; Flegel, Ashlie B.

    2015-01-01

    Variable-Speed Power Turbines (VSPT) for rotorcraft applications operate at low Reynolds number and over a wide range in incidence associated with shaft speed change. A comprehensive linear cascade data set obtained includes the effects of Reynolds number, free-stream turbulence and incidence is available and this paper concerns itself with the presentation and numerical simulation of conditions resulting in a selected set of those data. As such, post-dictions of blade pressure loading, total-pressure loss and exit flow angles under conditions of high and low turbulence intensity for a single Reynolds number are presented. Analyses are performed with the three-equation turbulence models of Walters- Leylek and Walters and Cokljat. Transition, loading, total-pressure loss and exit angle variations are presented and comparisons are made with experimental data as available. It is concluded that at the low freestream turbulence conditions the Walters-Cokljat model is better suited to predictions while for high freestream conditions the two models generate similar predications that are generally satisfactory.

  11. Effects of the current boundary conditions at the plasma-gun gap on density in SSPX

    Science.gov (United States)

    Kolesnikov, Roman; Lodestro, L. L.; Meyer, W. H.

    2012-10-01

    The Sustained Spheromak Physics Experiment (SSPX) was a toroidal magnetic-confinement device without toroidal magnetic-field coils or a central transformer but which generated core-plasma currents by dynamo processes driven by coaxial plasma-gun injection into a flux-conserving vessel. Record electron temperatures in a spheromak (Te˜500eV) were achieved, and final results of the SSPX program were reported in [1]. Plasma density, which depended strongly on wall conditions, was an important parameter in SSPX. It was observed that density rises with Igun and that confinement improved as the density was lowered. Shortly after the last experiments, a new feature was added to the Corsica code's solver used to reconstruct SSPX equilibria. Motivated by n=0 fields observed in NIMROD simulations of SSPX, an insulating boundary condition was implemented at the plasma-gun gap. Using this option we will perform new reconstructions of SSPX equilibria and look for correlations between the location of the separatrix (which moves up the gun wall and onto the insulating gap as Igun increases) and plasma density and magnetic-flux amplification [2].[4pt] [1] H. S. McLean, APS, DPP, Dallas, TX, 2008.[0pt] [2] E. B. Hooper et al., Nucl. Fusion 47, 1064 (2007).

  12. Clinical compliance of viewing conditions in radiology reporting environments against current guidelines and standards

    Science.gov (United States)

    Daly, S.; Rainford, L.; Butler, M. L.

    2014-03-01

    Several studies have demonstrated the importance of environmental conditions in the radiology reporting environment, with many indicating that incorrect parameters could lead to error and misinterpretation. Literature is available with recommendations as to the levels that should be achieved in clinical practice, but evidence of adherence to these guidelines in radiology reporting environments is absent. This study audited the reporting environments of four teleradiologist and eight hospital based radiology reporting areas. This audit aimed to quantify adherence to guidelines and identify differences in the locations with respect to layout and design, monitor distance and angle as well as the ambient factors of the reporting environments. In line with international recommendations, an audit tool was designed to enquire in relation to the layout and design of reporting environments, monitor angle and distances used by radiologists when reporting, as well as the ambient factors such as noise, light and temperature. The review of conditions were carried out by the same independent auditor for consistency. The results obtained were compared against international standards and current research. Each radiology environment was given an overall compliance score to establish whether or not their environments were in line with recommended guidelines. Poor compliance to international recommendations and standards among radiology reporting environments was identified. Teleradiology reporting environments demonstrated greater compliance than hospital environments. The findings of this study identified a need for greater awareness of environmental and perceptual issues in the clinical setting. Further work involving a larger number of clinical centres is recommended.

  13. EXPERIMENTAL AND THEORETICAL DETERMINATION OF HEAVY OIL VISCOSITY UNDER RESERVOIR CONDITIONS

    Energy Technology Data Exchange (ETDEWEB)

    Dr. Jorge Gabitto; Maria Barrufet

    2003-05-01

    The USA deposits of heavy oils and tar sands contain significant energy reserves. Thermal methods, particularly steam drive and steam soak, are used to recover heavy oils and bitumen. Thermal methods rely on several displacement mechanisms to recover oil, but the most important is the reduction of crude viscosity with increasing temperature. The main objective of this research is to propose a simple procedure to predict heavy oil viscosity at reservoir conditions as a function of easily determined physical properties. This procedure will avoid costly experimental testing and reduce uncertainty in designing thermal recovery processes. First, we reviewed critically the existing literature choosing the most promising models for viscosity determination. Then, we modified an existing viscosity correlation, based on the corresponding states principle in order to fit more than two thousand commercial viscosity data. We collected data for compositional and black oil samples (absence of compositional data). The data were screened for inconsistencies resulting from experimental error. A procedure based on the monotonic increase or decrease of key variables was implemented to carry out the screening process. The modified equation was used to calculate the viscosity of several oil samples where compositional data were available. Finally, a simple procedure was proposed to calculate black oil viscosity from common experimental information such as, boiling point, API gravity and molecular weight.

  14. Experimental and numerical evaluation of a solar passive cooling system under hot and humid climatic conditions

    Energy Technology Data Exchange (ETDEWEB)

    Rincon, Jose; Almao, Nastia [Universidad del Zulia, Lab. de Simulacion Computacional, Zulia (Venezuela); Gonzalez, Eduardo [Universidad del Zulia, Inst. de Investigaciones de la Facultad de Arquitectura, Zulia (Venezuela)

    2001-07-01

    The thermal performance of a solar passive cooling system (SPCS) under a hot and humid climate is experimentally and numerically evaluated. The experimental data were obtained from two full scale cells, with identical walls, but different roof configurations. One cell has a highly-insulated roof and the other has an SPCS incorporated consisting of a thermal mass (water), which is cooled by evaporation and long wave nocturnal radiation. The study was conducted taking into account the local climatic conditions of Maracaibo, a tropical city located in Venezuela. The numerical evaluation was accomplished using the computational code 'EVITA' which is based on the finite volume approach with high order bounded treatment of the convective terms. A PISO-like solution algorithm is used to solve the transient form of the continuity, momentum and energy equations. It has been demonstrated experimentally and numerically that under a hot and humid climate, it is possible to keep the indoor temperature below the outdoor temperature, using a passive cooling technique of a roof pond. The numerical results obtained using the model have demonstrated that the computational code used is a suitable cost-efficient alternative for the thermal performance evaluation of SPCS. (Author)

  15. Experimental evaluation of automotive air-conditioning using HFC-134a and HC-134a

    Science.gov (United States)

    Nasution, Henry; Zainudin, Muhammad Amir; Aziz, Azhar Abdul; Latiff, Zulkarnain Abdul; Perang, Mohd Rozi Mohd; Rahman, Abd Halim Abdul

    2012-06-01

    An experimental study to evaluate the energy consumption of an automotive air conditioning is presented. In this study, these refrigerants will be tested using the experimental rig which simulated the actual cars as a cabin complete with a cooling system component of the actual car that is as the blower, evaporator, condenser, radiators, electric motor, which acts as a vehicle engine, and then the electric motor will operate the compressor using a belt and pulley system, as well as to the alternator will recharge the battery. The compressor working with the fluids HFC-134a and HC-134a and has been tested varying the speed in the range 1000, 1500, 2000 and 2500 rpm. The measurements taken during the one hour experimental periods at 2-minutes interval times for temperature setpoint of 20°C with internal heat loads 0, 500, 700 and 1000 W. The final results of this study show an overall better energy consumption of the HFC-134a compared with the HC-134a.

  16. DIET OF EUROPEAN GRAYLING (THYMALLUS THYMALLUS L. FROM RIVERS OF THE ZAKARPATTYA IN CURRENT CONDITIONS

    Directory of Open Access Journals (Sweden)

    A. Khandozhivska

    2014-06-01

    Full Text Available Purpose. Determination of the diet spectrum of European grayling (Thymallus thymallus, qualitative and quantitative composition of the gut content of age groups (2+, 1+, 0+ from Teresva and Tereblya Rivers of the Zakarpattia region. Methodology. The initial material at a quantity of 28 multiple age individuals of European grayling was collected during field works in Zakarpattia rivers. The material was collected with the assistance of Zakarpattia Fish Protection Inspection. Fish were taken from poachers’ fishing nets in a fatal condition, then they were preserved in a 10% formalin solution. Processing of preserved material was conducted in laboratory conditions. The diet of multiple-age groups (2+, 1+, 0+ of European grayling from Teresva and Tereblya rivers of the Zakarpattia region was investigated. Findings. It was found that European grayling consumed mainly benthic invertebrates, preferring amphibiotic organisms of Insecta class. Diptera, Trichoptera, Plecoptera, Coleoptera, Ephemeroptera, Odonata, and Amphipoda representatives were common in the diet of age-2+, 1+, 0+ fish. Gut fullness content index of young-of-the-year grayling with an average weight of 12,3 ± 0,72 g was in average 384,54 ± 114,01 %оо, age-2+ fish with an average weight of 29,53 ± 2,14 g – 177,75 ± 16,41 %оо, and age-3+ fish with an average weight of 91,4 ± 11,42 g – 168,49 ± 25,44 %оо, respectively. Originality. Information on European grayling diet in the Zakarpattia rivers in current conditions is insufficient because this species in listed in the Red Book of Ukraine that limits obtaining the materials for its studies. Practical value. The obtained data allow scientifically justified determining the stocking amounts of European grayling juveniles for increasing its natural populations in the rivers of Zakarpattia.

  17. Determination of the Conditional-Constant Component of the Bank’s Current Liabilities

    Directory of Open Access Journals (Sweden)

    Anatoly Pavlovich Vozhzhov

    2016-03-01

    Full Text Available The article deals with the questions of the definition of the semi-constant component of current liabilities of a bank. The purpose of this article is to develop a scientific and methodological approach to determine the semi-constant component of the current liabilities of a bank under the conditions of the complexity of data acquisition and processing of the data on factors that influence on demand deposits. The main hypothesis is the assumption of the heterogeneity of the variance of the daily cumulative sum of demand deposits. The analysis of scientific and methodological approaches that allow determining a stable component of current liabilities proves the need for further improvement of scientific instruments. In particular, a coefficient analysis that is proposed by some of the scholars, mainly, considers the average values of turnover on accounts, which in turn, can vary considerably throughout the calendar year. The use of the probability distributions to determine the expected value of the constant sum of deposits is possible only in the case of “ideal” financial conditions, when the impact of factors on the aggregate sum of deposits is not taken into account. The developed statistical models leave out the possible heterogeneity of the dispersion of this balance. In the article, it is proposed to apply econometric methods, namely, the methods of time series analysis to test the hypothesis of the variance heterogeneity of the cumulative sum of demand deposits, using daily data. In particular, the formalization and evaluation of EGARCH-model parameters are conducted. The EGARCH-model allows to take into account the non-linear, asymmetric effects of fluctuations in the financial series. The determination of the conditionalconstant component of demand deposits is proposed on the basis of the revealed regularities. The results of the research prove the hypothesis of the non-stationary character of the variance in daily balance of demand

  18. Experimental verification of boundary conditions for numerical simulation of airflow in a benchmark ventilation channel

    Directory of Open Access Journals (Sweden)

    Lizal Frantisek

    2016-01-01

    Full Text Available Correct definition of boundary conditions is crucial for the appropriate simulation of a flow. It is a common practice that simulation of sufficiently long upstream entrance section is performed instead of experimental investigation of the actual conditions at the boundary of the examined area, in the case that the measurement is either impossible or extremely demanding. We focused on the case of a benchmark channel with ventilation outlet, which models a regular automotive ventilation system. At first, measurements of air velocity and turbulence intensity were performed at the boundary of the examined area, i.e. in the rectangular channel 272.5 mm upstream the ventilation outlet. Then, the experimentally acquired results were compared with results obtained by numerical simulation of further upstream entrance section defined according to generally approved theoretical suggestions. The comparison showed that despite the simple geometry and general agreement of average axial velocity, certain difference was found in the shape of the velocity profile. The difference was attributed to the simplifications of the numerical model and the isotropic turbulence assumption of the used turbulence model. The appropriate recommendations were stated for the future work.

  19. Experimental investigation of transient thermal behavior of an airship under different solar radiation and airflow conditions

    Science.gov (United States)

    Li, De-Fu; Xia, Xin-Lin; Sun, Chuang

    2014-03-01

    Knowledge of the thermal behavior of airships is crucial to the development of airship technology. An experiment apparatus is constructed to investigate the thermal response characteristics of airships, and the transient temperature distributions of both hull and inner gas are obtained under the irradiation of a solar simulator and various airflow conditions. In the course of the research, the transient temperature change of the experimental airship is measured for four airflow speeds of 0 m/s (natural convection), 3.26 m/s, 5.5 m/s and 7.0 m/s, and two incident solar radiation values of 842.4 W/m2 and 972.0 W/m2. The results show that solar irradiation has significant influence on the airship hull and inner gas temperatures even if the airship stays in a ground airflow environment where the heat transfer is dominated by radiation and convection. The airflow around the airship is conducive to reduce the hull temperature and temperature nonuniformity. Transient thermal response of airships rapidly varies with time under solar radiation conditions and the hull temperature remains approximately constant in ˜5-10 min. Finally, a transient thermal model of airship is developed and the model is validated through comparison with the experimental data.

  20. Experimental cooling during incubation leads to reduced innate immunity and body condition in nestling tree swallows.

    Science.gov (United States)

    Ardia, Daniel R; Pérez, Jonathan H; Clotfelter, Ethan D

    2010-06-22

    Nest microclimate can have strong effects that can carry over to later life-history stages. We experimentally cooled the nests of tree swallows (Tachycineta bicolor). Females incubating in cooled nests reduced incubation time and allowed egg temperatures to drop, leading to extended incubation periods. We partially cross-fostered nestlings to test carry-over effects of cooling during incubation on nestling innate constitutive immunity, assessed through bacteria killing ability (BKA) of blood. Nestlings that had been cooled as eggs showed a lower ability to kill bacteria than control nestlings, regardless of the treatment of their foster mother. However, there was no effect of treatment of rearing females on nestling BKA in control nestlings, even though cooled females made significantly fewer feeding visits than did control females. This suggests that the effect of cooling occurred during incubation and was not due to carry-over effects on nestling condition. Nestlings that were exposed to experimental cooling as embryos had lower residual body mass and absolute body mass at all four ages measured. Our results indicate that environmental conditions and trade-offs experienced during one stage of development can have important carry-over effects on later life-history stages.

  1. Experimental investigations on a common centrifugal pump operating under gas entrainment conditions

    Energy Technology Data Exchange (ETDEWEB)

    Schäfer, Thomas, E-mail: thomas.schaefer@hzdr.de [Helmholtz-Zentrum Dresden-Rossendorf, Institute of Fluid Dynamics (Germany); Neumann, Martin [Technische Universität Dresden, AREVA Endowed Chair of Imaging Techniques in Energy and Process Engineering (Germany); Bieberle, André [Helmholtz-Zentrum Dresden-Rossendorf, Institute of Fluid Dynamics (Germany); Hampel, Uwe [Helmholtz-Zentrum Dresden-Rossendorf, Institute of Fluid Dynamics (Germany); Technische Universität Dresden, AREVA Endowed Chair of Imaging Techniques in Energy and Process Engineering (Germany)

    2017-05-15

    Highlights: • The pump performance has been evaluated for several gas entrainment conditions. • The gas entraining flow regime has a large impact on the pump performance. • High-resolution gamma-ray computed tomography (HireCT) has been applied. • Gas holdup inside the operating impeller has been visualized and quantified. • Gas holdup profiles along selected streamlines have been calculated. - Abstract: This paper presents an experimental study on the effects of additional gas entrainment in centrifugal pumps designed for conveying liquid phases only. The pump performance has been evaluated for several gas entrainment conditions, and for various operational settings of the pump, such as its alignment and the rotational speed of the impeller. As a main performance indicator the impact of entrained gas on the hydraulic power of the pump has been analyzed using experimental data. Additionally, high-resolution gamma-ray computed tomography (HireCT) operated in time-averaged rotation-synchronized scanning mode has been applied to quantify local phase fraction distributions inside the rapidly rotating pump impeller. Based on these quantitative tomographic measurements, gas holdup profiles along selected streamlines have been calculated and gas accumulation areas inside the impeller chambers have been visualized. Thus, various internally accumulated gas holdup patterns have been identified and, eventually, associated with characteristic pump performance behaviors. Moreover, the tomographic measuring method allowed an enhanced gas holdup analysis in specified pump compartments. As a result, the related specific gas and liquid phase holdup profiles have been evaluated.

  2. Experimental investigation on the CHF in the narrow rectangular channel under the downward flow condition

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Huiyung; Yun, Byongjo; Bak, Jinyeong [Pusan national university, Pusan (Korea, Republic of); Park, Jonghark; Chae, Heetaek; Park, Cheol [KAERI, Daejeon (Korea, Republic of)

    2015-05-15

    The new research reactor under constructing in Kijang adopts a plate-type-fuel with downward flow cooling to prevent release of radioactive substance at pool surface. The thermal hydraulic design for the narrow rectangular channel differs from that for rod bundle channel. The licensing for construction of research reactor requires thermal hydraulic safety analysis of narrow rectangular channel. In the thermal hydraulic safety analysis, critical heat flux (CHF) on the fuel surface is considerably important to determine power and safety margin. The objectives of present study are, therefore, to carry out the experiment of CHF for downward flow in narrow rectangular channel, to obtain the correlation of CHF prediction applicable to a subchannel of plate-type-fuel. CHF experiments were carried out in the narrow rectangular channel simulating plate-type-fuel for research reactors under the downward flow condition. With the investigation of CHF data of the present experiment and previous studies, a new CHF correlation was proposed for the downward flow in the subchannel of plate-type-fuel. The predicted CHF by the new CHF correlation shows good agreement with experimental data in the present study. However, the correlation was based on the limited number of experimental data under low-flow conditions. Therefore, further studies for more data are needed to generalize the CHF correlation.

  3. Computational ecotoxicology: simultaneous prediction of ecotoxic effects of nanoparticles under different experimental conditions.

    Science.gov (United States)

    Kleandrova, Valeria V; Luan, Feng; González-Díaz, Humberto; Ruso, Juan M; Melo, André; Speck-Planche, Alejandro; Cordeiro, M Natália D S

    2014-12-01

    Nanotechnology has brought great advances to many fields of modern science. A manifold of applications of nanoparticles have been found due to their interesting optical, electrical, and biological/chemical properties. However, the potential toxic effects of nanoparticles to different ecosystems are of special concern nowadays. Despite the efforts of the scientific community, the mechanisms of toxicity of nanoparticles are still poorly understood. Quantitative-structure activity/toxicity relationships (QSAR/QSTR) models have just started being useful computational tools for the assessment of toxic effects of nanomaterials. But most QSAR/QSTR models have been applied so far to predict ecotoxicity against only one organism/bio-indicator such as Daphnia magna. This prevents having a deeper knowledge about the real ecotoxic effects of nanoparticles, and consequently, there is no possibility to establish an efficient risk assessment of nanomaterials in the environment. In this work, a perturbation model for nano-QSAR problems is introduced with the aim of simultaneously predicting the ecotoxicity of different nanoparticles against several assay organisms (bio-indicators), by considering also multiple measures of ecotoxicity, as well as the chemical compositions, sizes, conditions under which the sizes were measured, shapes, and the time during which the diverse assay organisms were exposed to nanoparticles. The QSAR-perturbation model was derived from a database containing 5520 cases (nanoparticle-nanoparticle pairs), and it was shown to exhibit accuracies of ca. 99% in both training and prediction sets. In order to demonstrate the practical applicability of our model, three different nickel-based nanoparticles (Ni) with experimental values reported in the literature were predicted. The predictions were found to be in very good agreement with the experimental evidences, confirming that Ni-nanoparticles are not ecotoxic when compared with other nanoparticles. The results

  4. Experimental Measurement of Asymmetric Fluctuations of Poloidal Magnetic Field in Damavand Tokomak at Different Plasma Currents

    Science.gov (United States)

    Moslehi-Fard, Mahmoud; Alinejad, Naser; Rasouli, Chapar; Sadigzadeh, Asghar

    2012-08-01

    Toroidal and Poloidal magnetic fields have an important effect on the tokomak topology. Damavand Tokomak is a small size tokomak characterized with k = 1.2, B t = 1T, R 0 = 36 cm, maximum plasma current is about 35 KA with a discharge time of 21 ms. In this experimental work, the variation of poloidal magnetic field on the torodial cross section is measured and analyzed. In order to measure the polodial magnetic field, 18 probes were installed on the edge of tokomak plasma with ∆θ = 18°, while a limiter was installed inside the torus. Plasma current, I p, induces a polodial magnetic field, B p, smaller than the torodial magnetic field B t. Magnetic lines B produced as a combination of B t and B p, are localized on the nested toroidal magnetic surfaces. The presence of polodial magnetic field is necessary for particles confinement. Mirnov oscillations are the fluctuations of polodial magnetic field, detected by magnetic probes. Disrupted instability in Tokomak typically starts with mirnov oscillations which appear as fluctuations of polodial magnetic field and is detected by magnetic probes. Minor disruptions inside the plasma can contain principal magnetic islands and their satellites can cause the annihilation of plasma confinement. Production of thin layer of turbulent magnetic field lines cause minor disruption. Magnetic limiter may cause the deformation of symmetric equilibrium configuration and chaotic magnetic islands reveal in plasma occurring in thin region of chaotic field lines close to their separatrix. The width of this chaotic layer in the right side of poloidal profile of Damavand Tokomak is smaller than the width in the left side profile because of Shafranov displacement. Ergodic region in the left side of profile develops a perturbation on the magnetic polodial field lines, B p, that are greater in magnitude than that in the right side, although the values of B p on the left side are smaller than that on the right side of the profile. The Left

  5. Three Gorges Reservoir Area: soil erosion under natural condition vs. soil erosion under current land use

    Science.gov (United States)

    Schönbrodt, Sarah; Behrens, Thorsten; Scholten, Thomas

    2010-05-01

    Apparently, the current most prominent human-induced example for large scale environmental impact is the Three Gorges Dam in China. The flooding alongside the Yangtze River, and its tributaries results in a vast loss of settlement and farmland area with productive, fertile valley soils. Due to the associated high land use dynamic on uphill-sites, the soil resources are underlying high land use pressure. Within our study, the soil erosion under natural conditions is compared to the soil erosion under current land use after the impoundment. Both were modeled using the empirical Universal Soil Loss Equation (USLE) which is able to predict long-term annual soil loss with limited data. The database consists of digital terrain data (45 m resolution DEM, erosive slope length based on Monte-Carlo-Aggregation according to Behrens et al. (2008)), field investigations of recent erosion forms, and literature studies. The natural disposition to soil erosion was calculated considering the USLE factors R, S, and K. The soil erosion under current land use was calculated taking into account all USLE factors. The study area is the catchment of the Xiangxi River in the Three Gorges Reservoir area. Within the Xiangxi Catchment (3,200 km²) the highly dynamic backwater area (580 km²), and two micro-scale study sites (Xiangjiaba with 2.8 km², and Quyuan with 88 km²) are considered more detailed as they are directly affected by the river impoundment. Central features of the Xiangxi Catchment are the subtropical monsoon climate, an extremely steep sloping relief (mean slope angle 39°, SD 22.8°) artificially fractured by farmland terraces, and a high soil erodibility (mean K factor 0.37, SD 0.13). On the catchment scale the natural disposition to soil erosion makes up to mean 518.0 t ha-1 a-1. The maximum potential soil loss of 1,730.1 t ha-1 a-1 under natural conditions is reached in the Quyuan site (mean 635.8 t ha-1 a-1) within the backwater area (mean 582.9 t ha-1 a-1). In the

  6. Early stages of wind wave and drift current generation under non-stationary wind conditions.

    Science.gov (United States)

    Robles-Diaz, Lucia; Ocampo-Torres, Francisco J.; Branger, Hubert

    2016-04-01

    Generation and amplification mechanisms of ocean waves are well understood under constant wind speed or limited fetch conditions. Under these situations, the momentum and energy transfers from air to water are also quite well known. However during the wind field evolution over the ocean, we may observe sometime high wind acceleration/deceleration situations (e.g. Mexican Tehuano or Mediterranean Mistral wind systems). The evolution of wave systems under these conditions is not well understood. The purpose of these laboratory experiments is to better understand the early stages of water-waves and surface-drift currents under non-stationary wind conditions and to determine the balance between transfers creating waves and surface currents during non-equilibrium situations. The experiments were conducted in the Institut Pythéas wind-wave facility in Marseille-France. The wave tank is 40 m long, 2.7 m wide and 1 m deep. The air section is 50 m long, 3 m wide and 1.8 m height. We used 11 different resistive wave-gauges located along the tank. The momentum fluxes in the air column were estimated from single and X hot-film anemometer measurements. The sampling frequency for wind velocity and surface displacement measurements was 256 Hz. Water-current measurements were performed with a profiling velocimeter. This device measures the first 3.5 cm of the water column with a frequency rate of 100Hz. During the experiments, the wind intensity was abruptly modified with a constant acceleration and deceleration over time. We observed that wind drag coefficient values for accelerated wind periods are lower than the ones reported in previous studies for constant wind speed (Large and Pond 1981; Ocampo-Torres et al. 2010; Smith 1980; Yelland and Taylor 1996). This is probably because the turbulent boundary layer is not completely developed during the increasing-wind sequence. As it was reported in some theoretical studies (Miles 1957; Phillips 1957; Kahma and Donelan 1988), we

  7. Establishment and performance of an experimental green roof under extreme climatic conditions.

    Science.gov (United States)

    Klein, Petra M; Coffman, Reid

    2015-04-15

    Green roofs alter the surface energy balance and can help in mitigating urban heat islands. However, the cooling of green roofs due to evapotranspiration strongly depends on the climatic conditions, and vegetation type and density. In the Southern Central Plains of the United States, extreme weather events, such as high winds, heat waves and drought conditions pose challenges for successful implementation of green roofs, and likely alter their standard performance. The National Weather Center Experimental Green Roof, an interdisciplinary research site established in 2010 in Norman, OK, aimed to investigate the ecological performance and surface energy balance of green roof systems. Starting in May 2010, 26 months of vegetation studies were conducted and the radiation balance, air temperature, relative humidity, and buoyancy fluxes were monitored at two meteorological stations during April-October 2011. The establishment of a vegetative community trended towards prairie plant dominance. High mortality of succulents and low germination of grasses and herbaceous plants contributed to low vegetative coverage. In this condition succulent diversity declined. Bouteloua gracilis and Delosperma cooperi showed typological dominance in harsh climatic conditions, while Sedum species experienced high mortality. The plant community diversified through volunteers such as Euphorbia maculate and Portulaca maculate. Net radiation measured at a green-roof meteorological station was higher than at a control station over the original, light-colored roofing material. These findings indicate that the albedo of the green roof was lower than the albedo of the original roofing material. The low vegetative coverage during the heat and drought conditions in 2011, which resulted in the dark substrate used in the green roof containers being exposed, likely contributed to the low albedo values. Nevertheless, air temperatures and buoyancy fluxes were often lower over the green roof indicating

  8. Current experimental perspectives on the clinical progression of alcoholic liver disease.

    Science.gov (United States)

    Breitkopf, Katja; Nagy, Laura E; Beier, Juliane I; Mueller, Sebastian; Weng, Honglei; Dooley, Steven

    2009-10-01

    Chronic alcohol abuse is an important cause of morbidity and mortality throughout the world. Liver damage due to chronic alcohol intoxication initially leads to accumulation of lipids within the liver and with ongoing exposure this condition of steatosis may first progress to an inflammatory stage which leads the way for fibrogenesis and finally cirrhosis of the liver. While the earlier stages of the disease are considered reversible, cirrhotic destruction of the liver architecture beyond certain limits causes irreversible damage of the organ and often represents the basis for cancer development. This review will summarize current knowledge about the molecular mechanisms underlying the different stages of alcoholic liver disease (ALD). Recent observations have led to the identification of new molecular mechanisms and mediators of ALD. For example, plasminogen activator inhibitor 1 was shown to play a central role for steatosis, the anti-inflammatory adipokine, adiponectin profoundly regulates liver macrophage function and excessive hepatic deposition of iron is caused by chronic ethanol intoxication and increases the risk of hepatocellular carcinoma development.

  9. Experimental study of elliptical jet from supercritical to subcritical conditions using planar laser induced fluorescence

    Science.gov (United States)

    Muthukumaran, C. K.; Vaidyanathan, Aravind

    2015-03-01

    The study of fluid jet dynamics at supercritical conditions involves strong coupling between fluid dynamic and thermodynamic phenomena. Beyond the critical point, the liquid-vapor coexistence ceases to exist, and the fluid exists as a single phase known as supercritical fluid with its properties that are entirely different from liquids and gases. At the critical point, the liquids do not possess surface tension and latent heat of evaporation. Around the critical point, the fluid undergoes large changes in density and possesses thermodynamic anomaly like enhancement in thermal conductivity and specific heat. In the present work, the transition of the supercritical and near-critical elliptical jet into subcritical as well as supercritical environment is investigated experimentally with nitrogen and helium as the surrounding environment. Under atmospheric condition, a liquid jet injected from the elliptical orifice exhibits axis switching phenomena. As the injection temperature increases, the axis switching length also increases. Beyond the critical temperature, the axis switching is not observed. The investigation also revealed that pressure plays a major role in determining the thermodynamic transition of the elliptical jet only for the case of supercritical jet injected into subcritical chamber conditions. At larger pressures, the supercritical jet undergoes disintegration and formation of droplets in the subcritical environment is observed. However, for supercritical jet injection into supercritical environment, the gas-gas like mixing behavior is observed.

  10. Experimental study of elliptical jet from supercritical to subcritical conditions using planar laser induced fluorescence

    Energy Technology Data Exchange (ETDEWEB)

    Muthukumaran, C. K.; Vaidyanathan, Aravind, E-mail: aravind7@iist.ac.in [Department of Aerospace Engineering, Indian Institute of Space Science and Technology, Trivandrum, Kerala 695547 (India)

    2015-03-15

    The study of fluid jet dynamics at supercritical conditions involves strong coupling between fluid dynamic and thermodynamic phenomena. Beyond the critical point, the liquid-vapor coexistence ceases to exist, and the fluid exists as a single phase known as supercritical fluid with its properties that are entirely different from liquids and gases. At the critical point, the liquids do not possess surface tension and latent heat of evaporation. Around the critical point, the fluid undergoes large changes in density and possesses thermodynamic anomaly like enhancement in thermal conductivity and specific heat. In the present work, the transition of the supercritical and near-critical elliptical jet into subcritical as well as supercritical environment is investigated experimentally with nitrogen and helium as the surrounding environment. Under atmospheric condition, a liquid jet injected from the elliptical orifice exhibits axis switching phenomena. As the injection temperature increases, the axis switching length also increases. Beyond the critical temperature, the axis switching is not observed. The investigation also revealed that pressure plays a major role in determining the thermodynamic transition of the elliptical jet only for the case of supercritical jet injected into subcritical chamber conditions. At larger pressures, the supercritical jet undergoes disintegration and formation of droplets in the subcritical environment is observed. However, for supercritical jet injection into supercritical environment, the gas-gas like mixing behavior is observed.

  11. A novel experimental procedure to investigate the biodegradation of NAPL under unsaturated conditions

    Science.gov (United States)

    Andre, Laurent; Kedziorek, Monika A. M.; Bourg, Alain C. M.; Haeseler, Frank; Blanchet, Denis

    2009-05-01

    SummarySoils need to be thoroughly investigated regarding their potential for the natural attenuation of non-aqueous phase liquids (NAPL). Laboratory investigations truly representative of degradation processes in field conditions are difficult to implement for porous media partially saturated with water, NAPL and air. We propose an innovative protocol to investigate degradation processes under steady-state vadose zone conditions. Experiments are carried out in glass columns filled with a sand and, as bacteria source, a soil from a diesel-fuel-polluted site. Water and NAPL ( n-hexadecane diluted in heptamethylnonane (HMN)) are added to the porous medium in a two-step procedure using ceramic membranes placed at the bottom of the column. This procedure results, for appropriate experimental conditions, in a uniform distribution of the two fluids (water and NAPL) throughout the column. In a biodegradation experiment non-biodegradable HMN is used to provide NAPL mass, while keeping biodegradable n-hexadecane small enough to monitor its rapid degradation. Biodegradation is followed as a function of time by measuring oxygen consumption, using a respirometer. Degradative activity is controlled by diffusive transfers in the porous network, of oxygen from the gas phase to the water phase and of n-hexadecane from the NAPL phase to the water phase.

  12. Comparison of Pavlovian serial conditional discrimination in rats and hamsters in the same experimental situation

    Directory of Open Access Journals (Sweden)

    J.L.O. Bueno

    2001-12-01

    Full Text Available The present study compares behavioral changes between two distinct rodent groups, hamsters (Mesocricetus auratus and Wistar rats, when submitted in the same homogeneous experimental situations to a serial conditional discrimination procedure which involves water deprivation and the processing of temporal variables. Both hamsters and rats acquired serial positive conditional discrimination as indicated by higher frequencies of magazine-oriented behavior during the tone followed by reinforcement (T+ and preceded by the feature stimulus light (L and during the empty interval, than during the tone alone not followed by reinforcement (T-. Rats' frequencies of magazine-oriented behavior were high during T+ and T-, initially during training, and decreased during T- as the training progressed. However, the hamsters' frequencies of magazine-oriented behavior started very low and increased only during T+ as the training progressed. Comparison of the frequencies of magazine-oriented behavior during the empty interval in relation to the frequencies during the preceding L period showed that rats' frequencies remained very high and hamsters' frequencies increased during training. These results suggest that rats and hamsters have different behavioral strategies for the acquisition of a conditional discrimination. The results of the comparisons made in these experiments support the view of the importance of an ecological psychology approach to the understanding of complex learning in animals.

  13. Simulations of the Richtmyer-Meshkov Instability with experimentally measured volumetric initial conditions

    Science.gov (United States)

    Ferguson, Kevin; Sewell, Everest; Krivets, Vitaliy; Greenough, Jeffrey; Jacobs, Jeffrey

    2016-11-01

    Initial conditions for the Richtmyer-Meshkov instability (RMI) are measured in three dimensions in the University of Arizona Vertical Shock Tube using a moving magnet galvanometer system. The resulting volumetric data is used as initial conditions for the simulation of the RMI using ARES at Lawrence-Livermore National Laboratory (LLNL). The heavy gas is sulfur hexafluoride (SF6), and the light gas is air. The perturbations are generated by harmonically oscillating the gasses vertically using two loudspeakers mounted to the shock tube which cause Faraday resonance, producing a random short wavelength perturbation on the interface. Planar Mie scattering is used to illuminate the flow field through the addition of propylene glycol particles seeded in the heavy gas. An M=1.2 shock impulsively accelerates the interface, initiating instability growth. Images of the initial condition and instability growth are captured at a rate of 6 kHz using high speed cameras. Comparisons between experimental and simulation results, mixing diagnostics, and mixing zone growth are presented.

  14. Experimental study on supporting technology of gob-side entry with different roof conditions

    Institute of Scientific and Technical Information of China (English)

    LUO Yong

    2012-01-01

    Aiming to effectively solve the problem of deep mining with safety and high efficiency,according to geological conditions,production and stress analysis in roadway surrounding rock,experimental studies on roadway supporting of workface 103 under three types of roof conditions with different supporting technologies and parameters were carried out based on the theory of supporting technology of gob-side entry.The results show the supporting of gob-side entry retaining is successful,and the deep surrounding rock is effectively controlled by field monitoring and drilling-hole photos.After stress in surrounding rock of roadways restores stable,the final roadway deformation of surrounding rock of haulage roadway and air-roadway are both about 300 mm; width of gob-side entry is 3.8-4.0 m and average height is 2.0-2.2 m; roadway section is above 8.0 m2,which solves the problems of gob-side entry retaining support strength and safe mining; necessary conditions of mining safety in workface 103 are met.

  15. Experimental fuel cell performance analysis under different operating conditions and bipolar plate designs

    Energy Technology Data Exchange (ETDEWEB)

    Iranzo, Alfredo; Pino, Javier; Rosa, Felipe [Energy Engineering Department, School of Engineering, University of Seville, Camino de los Descubrimientos s/n, 41092 Seville (Spain); Munoz, Miguel; Lopez, Eduardo [INTA - National Institute for Aerospace Technology, Ctra. San Juan del Puerto-Matalascanas km 33, 21130 Mazagon (Huelva) (Spain)

    2010-10-15

    This work presents experimental performance results for a 50 cm{sup 2} Polymer Electrolyte Membrane (PEM) Fuel Cell, including polarization curves and Electrochemical Impedance Spectroscopy (EIS) analysis of the Fuel Cell. EIS results were used for the determination of the cell ohmic resistance as well as charge transfer resistances under different operating conditions. Different combinations of operating conditions and bipolar plate designs were analysed. In particular, the effect of the cathode oxygen concentration, reactant gases humidification, and bipolar plate (BP) design were assessed. Butler-Volmer (BV) kinetic parameters such as the charge transfer coefficient were also determined from Tafel plots. The electronic contact resistances were measured for both Bipolar Plate designs, and the membrane protonic resistances were calculated. Its dependence on the BP flow field design and operating conditions is addressed. The results obtained in this work are aimed both at gaining insight into the fundamental processes determining the fuel cell performance, and at determining parameters needed for Computational Fuel Cell Dynamics (CFCD) numerical simulations. (author)

  16. 'I think it will eventually be done away with': Attitudes among healthcare professionals towards the current system of animal experimentation.

    Science.gov (United States)

    Dignon, Andrée

    2016-08-01

    This article describes a study of attitudes to the current system of animal experimentation (for the production of health interventions) among 52 UK healthcare professionals. These healthcare professionals participated in three separate focus groups (of 18, 17 and 17 participants) and were invited to respond to the question 'what is your opinion about the current system of animal testing?' The study focused specifically on their views of the current system (rather than their views of animal testing in general). The healthcare professionals were critical of the current system, particularly with regard to regulation, secrecy, validity, unnecessary suffering and welfare. © The Author(s) 2014.

  17. The Current Condition and Possibilities of Development of Festival Tourism in the Lublin Region

    Directory of Open Access Journals (Sweden)

    Pioš Katarzyna

    2014-07-01

    Full Text Available Introduction. The number, range, and diversity of events with a character of festivals have been growing in the Lublin Region over the last several years. The events are organised by various entities and institutions. Information about them is largely dispersed. No study has been conducted so far determining the spatial distribution of festivals at the regional scale, and analysing their offer in the context of possibilities of development of festival tourism. Therefore, a study in the scope was undertaken with consideration of the cultural conditionings of some of the events. Material and methods. In periods from July to December 2010 and from September to December 2013, secondary information was analysed (statistics, records, and scientific studies, and original material was collected (field inventory, interview, and diagnostic survey regarding the current condition of festival tourism in the Lublin Region. Results. The collected data on festival tourism offers suggest that the number of festivals in the Lublin Region has been continuously increasing from year to year. According to the obtained data, festivals with a duration of 3 and 5 days are dominant. The majority of festivals are held in summer months, usually on weekends. Music and interdisciplinary festivals with international, national, and regional range are prevalent. Some of them already have a history of 47 years. The analysis of the spatial distribution of the festivals subject to the inventory suggests that the majority of them are organised in the largest cities of the region, namely Lublin, Zamośæ, and Kazimierz Dolny. Conclusions. Due to the very diverse offer of festivals, and the manner of their promotion, they play an important role in the promotion of the Lublin Region. The offer, spatial distribution, and dynamics in the scope of organisation of festivals provide good perspectives for the development of festival tourism in the Lublin Region.

  18. THE PECULIARITIES OF THE U. S. HIGHER EDUCATION DEVELOPMENT STRATEGY IN THE CONTEXT OF CURRENT CONDITIONS

    Directory of Open Access Journals (Sweden)

    Olga I. Fomina

    2014-01-01

    Full Text Available Abstract. The aim of the research is to investigate a current state of the US higher education and to show obstacles in a way of its innovative perfection; to reveal specificity of the US state policy concerning the higher school; to define factors that influence the effectiveness of the American research universities during the last decades. Methods. The author applies for methods of the retrospective and logic analysis while considering social and economic conditions and features of functioning of the American higher educational institutions during the latter half of 20th – the early 21st centuries. Conclusions on a condition and prospects of development of the US higher education are made on the basis of the review and the author’s interpretation of original documentary sources tenor and the official statistical data. Results. The author specifies the groups of factors that provide functioning efficiency of leading research universities of the USA. The research findings demonstrate that the diversification of funding sources, the concentration of talents in professorial, scientific, student communities, the guarantee of the academic mobility, and the favorable management structure of the US universities allow to lower dependence on economic instability, to provide development dynamism and adequately react to present calls. The characteristic of the system developed in the present period of the US higher education is given; the directions of its innovative development in modern conditions are defined. Scientific novelty. The author singles out and proves the problems of the US higher school caused by an economic crisis in the early 21st century and essentially affected the state strategy in educational management sphere and the corporate policy of high schools, taking into consideration the inescapable fact that features of the US higher education system are caused by aspiration of this state to hold the leading positions in the world

  19. Experimental Investigation of Pressure-volume-Temperature Mass Gauging Method Under Microgravity Condition by Parabolic Flight

    Science.gov (United States)

    Seo, Mansu; Park, Hana; Yoo, DonGyu; Jung, Youngsuk; Jeong, Sangkwon

    Gauging the volume or mass of liquid propellant of a rocket vehicle in space is an important issue for its economic feasibility and optimized design of loading mass. Pressure-volume-temperature (PVT) gauging method is one of the most suitable measuring techniques in space due to its simplicity and reliability. This paper presents unique experimental results and analyses of PVT gauging method using liquid nitrogen under microgravity condition by parabolic flight. A vacuum-insulated and cylindrical-shaped liquid nitrogen storage tank with 9.2 L volume is manufactured by observing regulation of parabolic flight. PVT gauging experiments are conducted under low liquid fraction condition from 26% to 32%. Pressure, temperature, and the injected helium mass into the storage tank are measured to obtain the ullage volume by gas state equation. Liquid volume is finally derived by the measured ullage volume and the known total tank volume. Two sets of parabolic flights are conducted and each set is composed of approximately 10 parabolic flights. In the first set of flights, the short initial waiting time (3 ∼ 5 seconds) cannot achieve sufficient thermal equilibrium condition at the beginning. It causes inaccurate gauging results due to insufficient information of the initial helium partial pressure in the tank. The helium injection after 12 second waiting time at microgravity condition with high mass flow rate in the second set of flights achieves successful initial thermal equilibrium states and accurate measurement results of initial helium partial pressure. Liquid volume measurement errors in the second set are within 11%.

  20. Experimental Validation of Modeled Fe Opacities at Conditions Approaching the Base of the Solar Convection Zone

    Science.gov (United States)

    Nagayama, Taisuke

    2013-10-01

    Knowledge of the Sun is a foundation for other stars. However, after the solar abundance revision in 2005, standard solar models disagree with helioseismic measurements particularly at the solar convection zone base (CZB, r ~ 0 . 7 ×RSun) [Basu, et al., Physics Reports 457, 217 (2008)]. One possible explanation is an underestimate in the Fe opacity at the CZB [Bailey et al., Phys. Plasmas 16, 058101 (2009)]. Modeled opacities are important physics inputs for plasma simulations (e.g. standard solar models). However, modeled opacities are not experimentally validated at high temperatures because of three challenging criteria required for reliable opacity measurements: 1) smooth and strong backlighter, 2) plasma condition uniformity, and 3) simultaneous measurements of plasma condition and transmission. Fe opacity experiments are performed at the Sandia National Laboratories (SNL) Z-machine aiming at conditions close to those at the CZB (i.e. Te = 190 eV, ne = 1 ×1023 cm-3). To verify the quality of the experiments, it is critical to investigate how well the three requirements are satisfied. The smooth and strong backlighter is provided by the SNL Z-pinch dynamic hohlraum. Fe plasma condition is measured by mixing Mg into the Fe sample and employing Mg K-shell line transmission spectroscopy. Also, an experiment is designed and performed to measure the level of non-uniformity in the Fe plasma by mixing Al and Mg dopants on the opposite side of the Fe sample and analyzing their spectra. We will present quantitative results on these investigations as well as the comparison of the measured opacity to modeled opacities. Sandia is a multi-program laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy under contract DE-AC04-94AL85000.

  1. Regime shifts of Cruces River wetland ecosystem: current conditions, future uncertainties

    Directory of Open Access Journals (Sweden)

    Víctor H Marín

    2014-03-01

    Full Text Available During April-May 2004 the Cruces River wetland ecosystem, located in Valdivia (40°S, southern Chile, was described as shifting from a clear water regime, dominated by the exotic macrophyte Egeria densa, to turbid waters and absence of submerged macrophytes. We analyzed the trophic status and ecological regime of the wetland from November 2011 through January 2013. The trophic status was determined comparing values of selected variables (nutrients, chlorophyll-a and transparency with OECD criteria. The ecological regime was determined comparing the same variables with the criteria proposed by Ibelings et al. (2007. We further compared the concentration of nutrients and suspended solids with previous measurements. Current trophic status of the wetland is between eutrophic and hypereutrophic, as shown by results, and its ecological regime intermediate, between clear and turbid waters, with a considerable risk of returning to turbid waters. In this article we discuss the potential relationship between the watershed land use (agriculture, cattle feeding and forestry, the change in wetland's trophic level and future conditions.

  2. STUDENT SATISFACTION, RESULTANT OF MARKETING ORIENTATION OF UNIVERSITY UNDER CURRENT CONDITIONS

    Directory of Open Access Journals (Sweden)

    Florentina DINESCU

    2012-12-01

    Full Text Available The purpose of this work is to present a relevant aspect of marketing approach of the activities carried by universities, respectively knowing, understanding and satisfying students’ needs, the main consumer category of the university product, in the conditions of current market of high education institutions. The universities are put in the position to find solutions to the problems caused by the stakeholders’ characteristics and by the existing competition on the educational market. The approach of marketing orientation in the university implies adapting the educational and scientific research step to create for the institution a brand image as a warranty of its sustainability on a competitive market by considering the needs and expectations of students. The conclusion is that there is a wide specialized literature that shows models that allow an adequate quantification of the students’ satisfaction as a resultant of concerning the insurance of high education quality by using univeristy marketing tools. Starting from the specialized literature, in the work was handled the quantification of the students’ satisfaction that have completed Bachelor and Master cycle in order to improve the activity of the university

  3. Methods for Management of Innovation Activity Risks in the Current Conditions

    Directory of Open Access Journals (Sweden)

    Pysmak Viktoriia O.

    2016-03-01

    Full Text Available The article considers theoretical foundations of management of innovation activity risks. Relevance of the selected topic of research in connection with both volatile external environment and crisis developments in the country's economy has been substantiated. A semantic analysis of the concept of «risk» has been done, showing the presence of both positive and negative sides of risk situations. A scheme for enterprise management in the light of implementing innovation activity has been elaborated. An improved classification of innovation activity has been provided, creating the opportunity to focus on identifying risks in the process of allocating a specific direction of innovation activity. The main stages of identification and analysis of risks of innovation activity has been allocated. Methods for management of innovation activity risks in the current conditions have been developed. A concept of «system for management of innovation activity risks» has been formulated, its major features for enterprise has been outlined. The main requirements for a system for management of innovation activity risks have been allocated.

  4. Experimental study on ignition characteristics of pulverized coal under high-temperature oxygen condition

    Science.gov (United States)

    Liu, G. W.; Liu, Y. H.; Dong, P.

    2016-08-01

    The high-temperature oxygen ignition technology of pulverized coal, which can replace the oil gun and achieve oil-free pulverized coal ignition by mixing the high- temperature oxygen and the pulverized coal stream directly, was proposed and a relevant ignition experimental system was built. The ignition characteristics of pulverized coal under high-temperature oxygen condition were investigated: the ignition process was described and analyzed, the influence of relevant parameters on the pulverized coal stream ignition were obtained and analyzed. The results showed: when the oxygen heating temperature is over 750 °C, the pulverized coal stream could be ignited successfully by high-temperature oxygen; increasing the pulverized coal concentration, primary air temperature and oxygen volume flow rate or decreasing the primary air velocity is helpful for the ignition and combustion of the pulverized coal stream.

  5. Experimental study of horizontal annular channels under non-developed conditions

    Energy Technology Data Exchange (ETDEWEB)

    Delgadino, G. [Rensselaer Polytechnic Institute, Troy, NY (United States); Balino, J.; Carrica, P. [Centro Atomico Bariloche e Instituto Balseriro (Argentina)

    1995-09-01

    In this work an experimental study of the two-phase air-water flow in a horizontal annular channel under non-developed conditions is presented. A conductive local probe was placed at the end of the channel to measure the local phase indication function under a wide range of gas and water flow rates. The signal was processed to obtain the void fraction and statistical distributions of liquid and gas residence times. From these data the topology of the flow could be inferred. A laser intermittence detector was also located close to the channel exit, in order to measure statistical parameters for intermittent flows by means of a two-probe method.

  6. The Study of Cutting Conditions Effects on the Damping Process Using the Experimental Taguchi Method

    Directory of Open Access Journals (Sweden)

    Haikel Mejri

    2016-01-01

    Full Text Available This article focuses on determining the effects of cutting conditions and their interactions on the cutting process damping in the case of curvilinear milling. The tests were performed using a numerical model simulation that allows the prediction of cutting forces and damping. The effects and interactions are determined using the Taguchi experimental method. Analysis of variance (ANOVA was performed to know the level of importance of the machining parameters on the cutting damping process. The results revealed that the Depth of cut Ap “C” and cutting speed Vc “B” have the most significant influence on the Cxx and Cxy process damping. The variations of tool diameter D “A” and clearance angle α have remarkable effects on the process damping Cxx. The “BC” interaction has the greatest effect on the process damping Cxx while the “AC” interaction has the greatest effect on the process damping Cxy.

  7. Exergo-Economic Analysis of an Experimental Aircraft Turboprop Engine Under Low Torque Condition

    Science.gov (United States)

    Atilgan, Ramazan; Turan, Onder; Aydin, Hakan

    Exergo-economic analysis is an unique combination of exergy analysis and cost analysis conducted at the component level. In exergo-economic analysis, cost of each exergy stream is determined. Inlet and outlet exergy streams of the each component are associated to a monetary cost. This is essential to detect cost-ineffective processes and identify technical options which could improve the cost effectiveness of the overall energy system. In this study, exergo-economic analysis is applied to an aircraft turboprop engine. Analysis is based on experimental values at low torque condition (240 N m). Main components of investigated turboprop engine are the compressor, the combustor, the gas generator turbine, the free power turbine and the exhaust. Cost balance equations have been formed for all components individually and exergo-economic parameters including cost rates and unit exergy costs have been calculated for each component.

  8. Non-verbal mother-child communication in conditions of maternal HIV in an experimental environment.

    Science.gov (United States)

    de Sousa Paiva, Simone; Galvão, Marli Teresinha Gimeniz; Pagliuca, Lorita Marlena Freitag; de Almeida, Paulo César

    2010-01-01

    Non-verbal communication is predominant in the mother-child relation. This study aimed to analyze non-verbal mother-child communication in conditions of maternal HIV. In an experimental environment, five HIV-positive mothers were evaluated during care delivery to their babies of up to six months old. Recordings of the care were analyzed by experts, observing aspects of non-verbal communication, such as: paralanguage, kinesics, distance, visual contact, tone of voice, maternal and infant tactile behavior. In total, 344 scenes were obtained. After statistical analysis, these permitted inferring that mothers use non-verbal communication to demonstrate their close attachment to their children and to perceive possible abnormalities. It is suggested that the mothers infection can be a determining factor for the formation of mothers strong attachment to their children after birth.

  9. The Experimental Investigation Of The Screen Operation In The Parametric Resonance Conditions

    Directory of Open Access Journals (Sweden)

    Bąk Łukasz

    2015-12-01

    Full Text Available In this paper the experimental studies of the screen working in the parametric resonance condition are discussed. The investigations are conducted for laboratory parametric resonance screen. The measuring test is performed for four cases of tension force values. The full sheet metal instead of the sieve is used. For each considered case the natural frequency of the plate and the parameter modulation frequency are determined. The achieved results are presented and discussed. It is shown that the highest sieve plate amplitude is obtained when the parameter modulation frequency is two times larger than natural frequency of the sieve plate. This parametric resonance vibration was observed only for tension force equal to 4000 N because of the rotational speed limits of electrical vibratos.

  10. Two current experimental problems in heavy lepton physics: tau decay modes and close mass pairs

    Energy Technology Data Exchange (ETDEWEB)

    Perl, M.L.

    1987-08-01

    This paper investigates tau lepton decay modes and close-mass lepton pairs. The major part of the paper discusses branching functions from experimental and theoretical viewpoints. Finally, the lack of experimental signatures of close-mass lepton pairs are reviewed. 15 refs., 2 figs., 11 tabs. (JDH)

  11. COMPUTATIONAL MODELING AND EXPERIMENTAL STUDIES ON NOx REDUCTION UNDER PULVERIZED COAL COMBUSTION CONDITIONS

    Energy Technology Data Exchange (ETDEWEB)

    Subha K. Kumpaty; Kannikeswaran Subramanian; Victor P. Nokku; Tyrus L. Hodges; Adel Hassouneh; Ansumana Darboe; Sravan K. Kumpati

    1998-06-01

    In this work, both computer simulation and experimental studies were conducted to investigate several strategies for NO{sub x} reduction under pulverized coal combustion conditions with an aim to meet the stringent environmental standards for NO{sub x} control. Both computer predictions and reburning experiments yielded favorable results in terms of NO{sub x} control by reburning with a combination of methane and acetylene as well as non-selective catalytic reduction of NO{sub x} with ammonia following reburning with methane. The greatest reduction was achieved at the reburning stoichiometric ratio of 0.9; the reduction was very significant, as clearly shown in Chapters III and V. Both the experimental and computational results favored mixing gases: methane and acetylene (90% and 10% respectively) and methane and ammonia (98% and 2%) in order to get optimum reduction levels which can not be achieved by individual gases at any amounts. Also, the above gaseous compositions as reburning fuels seemed to have a larger window of stoichiometric ratio (SR2 < 0.9) as opposed to just methane (SR2=0.9) so as to reduce and keep NO{sub x} at low ppm levels. From the various computational runs, it has been observed that although there are several pathways that contribute to NO{sub x} reduction, the key pathway is NO {r_arrow} HCN {r_arrow} NH{sub 3} {r_arrow} N{sub 2} + H{sub 2}. With the trends established in this work, it is possible to scale the experimental results to real time industrial applications using computational calculations.

  12. Preventative and Therapeutic Probiotic Use in Allergic Skin Conditions: Experimental and Clinical Findings

    Directory of Open Access Journals (Sweden)

    Öner Özdemir

    2013-01-01

    Full Text Available Probiotics are ingested live microbes that can modify intestinal microbial populations in a way that benefits the host. The interest in probiotic preventative/therapeutic potential in allergic diseases stemmed from the fact that probiotics have been shown to improve intestinal dysbiosis and permeability and to reduce inflammatory cytokines in human and murine experimental models. Enhanced presence of probiotic bacteria in the intestinal microbiota is found to correlate with protection against allergy. Therefore, many studies have been recently designed to examine the efficacy of probiotics, but the literature on the allergic skin disorders is still very scarce. Here, our objective is to summarize and evaluate the available knowledge from randomized or nonrandomized controlled trials of probiotic use in allergic skin conditions. Clinical improvement especially in IgE-sensitized eczema and experimental models such as atopic dermatitis-like lesions (trinitrochlorobenzene and picryl chloride sensitizations and allergic contact dermatitis (dinitrofluorobenzene sensitization has been reported. Although there is a very promising evidence to recommend the addition of probiotics into foods, probiotics do not have a proven role in the prevention or the therapy of allergic skin disorders. Thus, being aware of possible measures, such as probiotics use, to prevent/heal atopic diseases is essential for the practicing allergy specialist.

  13. Experimental conditions improving in-solution target enrichment for ancient DNA.

    Science.gov (United States)

    Cruz-Dávalos, Diana I; Llamas, Bastien; Gaunitz, Charleen; Fages, Antoine; Gamba, Cristina; Soubrier, Julien; Librado, Pablo; Seguin-Orlando, Andaine; Pruvost, Mélanie; Alfarhan, Ahmed H; Alquraishi, Saleh A; Al-Rasheid, Khaled A S; Scheu, Amelie; Beneke, Norbert; Ludwig, Arne; Cooper, Alan; Willerslev, Eske; Orlando, Ludovic

    2016-08-27

    High-throughput sequencing has dramatically fostered ancient DNA research in recent years. Shotgun sequencing, however, does not necessarily appear as the best-suited approach due to the extensive contamination of samples with exogenous environmental microbial DNA. DNA capture-enrichment methods represent cost-effective alternatives that increase the sequencing focus on the endogenous fraction, whether it is from mitochondrial or nuclear genomes, or parts thereof. Here, we explored experimental parameters that could impact the efficacy of MYbaits in-solution capture assays of ~5000 nuclear loci or the whole genome. We found that varying quantities of the starting probes had only moderate effect on capture outcomes. Starting DNA, probe tiling, the hybridization temperature and the proportion of endogenous DNA all affected the assay, however. Additionally, probe features such as their GC content, number of CpG dinucleotides, sequence complexity and entropy and self-annealing properties need to be carefully addressed during the design stage of the capture assay. The experimental conditions and probe molecular features identified in this study will improve the recovery of genetic information extracted from degraded and ancient remains.

  14. Experimental Study of the Influence of Surface Conditions on Explosive Electron Emission From a Pin Cathode

    Science.gov (United States)

    Pikuz, S. A.; Shelkovenko, T. A.; Hammer, D. A.; Parkevich, E. V.; Tilikin, I. N.; Mingaleev, A. R.; Agafonov, A. V.

    2016-10-01

    Most theories of Explosive Electron Emission are based on the idea of cathode flares developing after explosion of metal whiskers on the cathode surface. The spatial structure of the flare, its origin and the process of flare development are still a matter of conjecture. In this work we used picosecond duration high resolution laser probing and X-pinch point-projection X-ray radiography to directly observe whisker explosion in a high-current diode. Pin cathodes made from thin 5-25 μm W, Cu or Mo wires were used as the load in return current circuits of hybrid X-pinches on the XP and BIN pulsers. Pin length, pin-anode gap and wire surface conditions were varied over a wide range. The diode current and voltage were measured. In experiments with small wire-anode gap (0.1 - 1 mm) development of the expanded dense core of the wire was observed except with lengths of 100-200 microns. Strong mitigation of the electron emission was observed in experiments with heated pins. Work at Cornell was supported by the NNSA Stewardship Sciences Academic Programs under DOE Cooperative Agreement No. DE-NA0001836. The work in Lebedev Institute was sponsored by the Russian Foundation for Basic Research Project No. 140201206.

  15. Establishment and performance of an experimental green roof under extreme climatic conditions

    Energy Technology Data Exchange (ETDEWEB)

    Klein, Petra M., E-mail: pkklein@ou.edu [School of Meteorology, University of Oklahoma, Norman, OK (United States); Coffman, Reid, E-mail: rcoffma4@kent.edu [College of Architecture and Environmental Design, Kent State University, Kent, OH (United States)

    2015-04-15

    Green roofs alter the surface energy balance and can help in mitigating urban heat islands. However, the cooling of green roofs due to evapotranspiration strongly depends on the climatic conditions, and vegetation type and density. In the Southern Central Plains of the United States, extreme weather events, such as high winds, heat waves and drought conditions pose challenges for successful implementation of green roofs, and likely alter their standard performance. The National Weather Center Experimental Green Roof, an interdisciplinary research site established in 2010 in Norman, OK, aimed to investigate the ecological performance and surface energy balance of green roof systems. Starting in May 2010, 26 months of vegetation studies were conducted and the radiation balance, air temperature, relative humidity, and buoyancy fluxes were monitored at two meteorological stations during April–October 2011. The establishment of a vegetative community trended towards prairie plant dominance. High mortality of succulents and low germination of grasses and herbaceous plants contributed to low vegetative coverage. In this condition succulent diversity declined. Bouteloua gracilis and Delosperma cooperi showed typological dominance in harsh climatic conditions, while Sedum species experienced high mortality. The plant community diversified through volunteers such as Euphorbia maculate and Portulaca maculate. Net radiation measured at a green-roof meteorological station was higher than at a control station over the original, light-colored roofing material. These findings indicate that the albedo of the green roof was lower than the albedo of the original roofing material. The low vegetative coverage during the heat and drought conditions in 2011, which resulted in the dark substrate used in the green roof containers being exposed, likely contributed to the low albedo values. Nevertheless, air temperatures and buoyancy fluxes were often lower over the green roof indicating

  16. Temporal dynamics of relief in avoidance conditioning and fear extinction: Experimental validation and clinical relevance.

    Science.gov (United States)

    Vervliet, Bram; Lange, Iris; Milad, Mohammed R

    2017-09-01

    The learning principles that guide the acquisition and extinction of avoidance are not fully understood. We developed a novel paradigm to study the temporal dynamics of relief, a putative reinforcer of avoidance, and the recovery of fear and avoidance following extinction. During conditioning, the avoidance action canceled the aversive unconditional stimulus (US), without terminating the predictive conditional stimulus (CS). Relief pleasantness was rated after fixed CS offsets, when US omission occured. Avoidance was effective to one CS, but not to another, to track stimulus-specific avoidance learning. Fear was extinguished under response prevention in a separate context. Recovery tests took place 24 h later, in both contexts and with a monetary cost added to the avoidance action. We found that avoidance gradually became stimulus-specific during conditioning, but hardly recovered during delayed testing. Across all phases, initial omissions of the aversive US triggered relief that gradually declined over consecutive omissions, in line with a theoretical prediction error signal. Participants that scored low on distress tolerance, however, displayed sustained levels of relief over continuous omissions. We propose that such forms of sustained relief may produce over-reinforcement of foregoing avoidance actions and promote the development of pathological avoidance. The current paradigm represents an efficacious tool to study the temporal dynamics of relief across avoidance learning and fear extinction and to characterize relief dysregulations in relation to psychopathology. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  17. Behavior of a DC zero-flux current sensor; Magnetic field analysis and comparison with experimental results

    Energy Technology Data Exchange (ETDEWEB)

    Campostrini, P.; Sonato, P. (Istituto Gas Ionizzati del CNR, Padova (IT))

    1991-09-01

    In this paper the magnetic section of the finite-element ANSYS code, and in particular its optimization feature has been used to predict the behaviour of a zero-flux current sensor, briefly described, which is intended to be used in a fusion experiment to measure pulsed currents up to 50 kA, over a bandwidth from DC to 10 k Hz. The computed results fit well with those coming from experimental tests performed on a prototype.

  18. Experimental conditions affect the outcome of Plasmodium falciparum platelet-mediated clumping assays

    Directory of Open Access Journals (Sweden)

    Rowe J Alexandra

    2008-11-01

    Full Text Available Abstract Background Platelet-mediated clumping of Plasmodium falciparum-infected erythrocytes (IE is a parasite adhesion phenotype that has been associated with severe malaria in some, but not all, field isolate studies. A variety of experimental conditions have been used to study clumping in vitro, with substantial differences in parasitaemia (Pt, haematocrit (Ht, and time of reaction between studies. It is unknown whether these experimental variables affect the outcome of parasite clumping assays. Methods The effects of Pt (1, 4 and 12%, Ht (2, 5 and 10% and time (15 min, 30 min, 1 h, 2 h on the clumping of P. falciparum clone HB3 were examined. The effects of platelet freshness and parasite maturity were also studied. Results At low Ht (2%, the Pt of the culture has a large effect on clumping, with significantly higher clumping occurring at 12% Pt (mean 47% of IE in clumps compared to 4% Pt (mean 26% IE in clumps or 1% Pt (mean 7% IE in clumps (ANOVA, p = 0.0004. Similarly, at low Pt (1%, the Ht of the culture has a large effect on clumping, with significantly higher clumping occurring at 10% Ht (mean 62% IE in clumps compared to 5% Ht (mean 25% IE in clumps or 2% Ht (mean 10% IE in clumps (ANOVA, p = 0.0004. Combinations of high Ht and high Pt were impractical because of the difficulty assessing clumping in densely packed IE and the rapid formation of enormous clumps that could not be counted accurately. There was no significant difference in clumping when fresh platelets were used compared to platelets stored at 4°C for 10 days. Clumping was a property of mature pigmented-trophozoites and schizonts but not ring stage parasites. Conclusion The Pt and Ht at which in vitro clumping assays are set up have a profound effect on the outcome. All previous field isolate studies on clumping and malaria severity suffer from potential problems in experimental design and methodology. Future studies of clumping should use standardized conditions and

  19. An experimental search for near-wall boundary conditions for large eddy simulation

    Science.gov (United States)

    Robinson, S. K.

    1982-01-01

    Instantaneous wall shear stress and streamwise velocities have been measured simultaneously in a flat plate, turbulent boundary layer at moderate Reynolds number in an effort to provide experimental support for large eddy simulations. Data were obtained by using a buried-wire wall shear gage and a hot-wire rake positioned in the log region of the flow. All data processing was accomplished with digital data analysis techniques on a minicomputer. Fluctuations of the instantaneous U plus versus Y plus profiles about a mean law of the wall are shown to be significant and complex. Peak cross-correlation values between wall shear stress and the velocities are high and reflect the passage of a large structure inclined at a small angle to the wall. Estimates of this angle are consistent with those made by other investigators. Conditional sampling techniques were used to detect the passage of various sizes and types of flow disturbances (events) and to estimate their mean frequency of occurrence. Events characterized by large and sudden streamwise accelerations were found to be highly coherent throughout the log region and were strongly correlated with large fluctuations in wall shear-stress. Phase randomness between the near-wall quantities and the outer velocities was small. The results suggest that the flow events detected by conditional sampling applied to velocities in the log region may be related to the bursting process.

  20. Experimental study of surfactant transfer in fluid systems in microgravity conditions

    Science.gov (United States)

    Kostarev, K. G.; Levtov, V. L.; Romanov, V. V.; Shmyrov, A. V.; Viviani, A.

    2010-02-01

    The paper presents the results of the space experiment studying the process of surfactant dissolution from a binary fluid drop in microgravity conditions. The experiment was performed during the flight of the space satellite "Foton M-3" in September 2007. Investigation of the surfactant diffusion was made using a new original setup based on the interferometric method. The experimental cuvette represented a thin Hele-Shaw cell filled with water, which surrounded a drop in the form of a short liquid cylinder with a free lateral surface. The drop consisted of a binary mixture, in which one of the components was the surfactant easily dissolved in water. The use of interferometry made it possible to visualize and investigate evolution of the surfactant distributions and the flow structures in the drop and the surrounding liquid. The characteristic stages of the dissolution process were identified, and the rate of the concentration front propagation was defined. It was shown that in microgravity conditions the process of surfactant diffusion through the interface did not initiate an intensive solutal Marangoni convection as contrasted to the case of terrestrial simulation. The observed phenomenon has its origins in the long-lived fields of surfactant concentration formed near the interface due to the absence of the gravitational mechanisms of motion and large characteristic time of admixture diffusion which is hundreds of times longer than the time of thermal diffusion.

  1. A simplified analytical model for dc plasma spray torch: influence of gas properties and experimental conditions

    Science.gov (United States)

    Rat, V.; Coudert, J. F.

    2006-11-01

    A simplified analytical model is proposed to evaluate some characteristics of the arc jet generated with a dc plasma torch, in the restricted area of atmospheric plasma spraying conditions. The plasma inside the anode nozzle is considered as stationary and is divided into the arc column and a surrounding cold layer which electrically insulates the plasma from the nozzle wall. Radiation and processes related to the arc attachment at the electrodes are not explicitly taken into account. Heat conduction is evaluated by using Kirchoff's potential, which is described, as it is done also for the electrical conductivity, as a function of the gas specific enthalpy instead of temperature. The model is used to calculate the specific enthalpy radial distribution. From that, and by introducing a mean isentropic coefficient, it is possible to calculate the axial velocity of the plasma jet at the nozzle exit and to evaluate the different pressure contributions. The comparison between predicted and previously measured plasma jet velocities shows good agreement for various experimental conditions.

  2. Experimental performance study of a proposed desiccant based air conditioning system.

    Science.gov (United States)

    Bassuoni, M M

    2014-01-01

    An experimental investigation on the performance of a proposed hybrid desiccant based air conditioning system referred as HDBAC is introduced in this paper. HDBAC is mainly consisted of a liquid desiccant dehumidification unit integrated with a vapor compression system (VCS). The VCS unit has a cooling capacity of 5.27 kW and uses 134a as refrigerant. Calcium chloride (CaCl2) solution is used as the working desiccant material. HDBAC system is used to serve low sensible heat factor applications. The effect of different parameters such as, process air flow rate, desiccant solution flow rate, evaporator box and condenser box solution temperatures, strong solution concentration and regeneration temperature on the performance of the system is studied. The performance of the system is evaluated using some parameters such as: the coefficient of performance (COPa), specific moisture removal and energy saving percentage. A remarkable increase of about 54% in the coefficient of performance of the proposed system over VCS with reheat is achieved. A maximum overall energy saving of about 46% is observed which emphasizes the use of the proposed system as an energy efficient air conditioning system.

  3. Experimental performance study of a proposed desiccant based air conditioning system

    Directory of Open Access Journals (Sweden)

    M.M. Bassuoni

    2014-01-01

    Full Text Available An experimental investigation on the performance of a proposed hybrid desiccant based air conditioning system referred as HDBAC is introduced in this paper. HDBAC is mainly consisted of a liquid desiccant dehumidification unit integrated with a vapor compression system (VCS. The VCS unit has a cooling capacity of 5.27 kW and uses 134a as refrigerant. Calcium chloride (CaCl2 solution is used as the working desiccant material. HDBAC system is used to serve low sensible heat factor applications. The effect of different parameters such as, process air flow rate, desiccant solution flow rate, evaporator box and condenser box solution temperatures, strong solution concentration and regeneration temperature on the performance of the system is studied. The performance of the system is evaluated using some parameters such as: the coefficient of performance (COPa, specific moisture removal and energy saving percentage. A remarkable increase of about 54% in the coefficient of performance of the proposed system over VCS with reheat is achieved. A maximum overall energy saving of about 46% is observed which emphasizes the use of the proposed system as an energy efficient air conditioning system.

  4. Experimental impedance investigation of an ultracapacitor at different conditions for electric vehicle applications

    Science.gov (United States)

    Zhang, Lei; Hu, Xiaosong; Wang, Zhenpo; Sun, Fengchun; Dorrell, David G.

    2015-08-01

    Ultracapacitors (UCs) are being increasingly deployed as a short-term energy storage device in various energy systems including uninterruptable power supplies, electrified vehicles, renewable energy systems, and wireless communication. They exhibit excellent power density and energy efficiency. The dynamic behavior of a UC, however, strongly depends on its impedance characteristics. In this paper, the impedance characteristics of a commercial UC are experimentally investigated through the well-adopted Electrochemical Impedance Spectroscopy (EIS) technique. The implications of the UC operating conditions (i.e., temperature and state of charge (SOC)) to the impedance are systematically examined. The results show that the impedance is highly sensitive to the temperature and SOC; and the temperature effect is more significant. In particular, the coupling effect between the temperature and SOC is illustrated, as well as the high-efficiency SOC window, which is highlighted. To further verify the reliability of the EIS-based investigation and to probe the sensitivity of UC parameters to the operating conditions, a dynamic model is characterized by fitting the collected impedance data. The interdependence of UC parameters (i.e., capacitance and resistance elements) on the temperature and SOC is quantitatively revealed. The impedance-based model is demonstrated to be accurate in two driving-cycle tests.

  5. Frequency domain averaging based experimental evaluation of gear fault without tachometer for fluctuating speed conditions

    Science.gov (United States)

    Sharma, Vikas; Parey, Anand

    2017-02-01

    In the purview of fluctuating speeds, gear fault diagnosis is challenging due to dynamic behavior of forces. Various industrial applications employing gearbox which operate under fluctuating speed conditions. For diagnostics of a gearbox, various vibrations based signal processing techniques viz FFT, time synchronous averaging and time-frequency based wavelet transform, etc. are majorly employed. Most of the time, theories about data or computational complexity limits the use of these methods. In order to perform fault diagnosis of a gearbox for fluctuating speeds, frequency domain averaging (FDA) of intrinsic mode functions (IMFs) after their dynamic time warping (DTW) has been done in this paper. This will not only attenuate the effect of fluctuating speeds but will also extract the weak fault feature those masked in vibration signal. Experimentally signals were acquired from Drivetrain Diagnostic Simulator for different gear health conditions i.e., healthy pinion, pinion with tooth crack, chipped tooth and missing tooth and were analyzed for the different fluctuating profiles of speed. Kurtosis was calculated for warped IMFs before DTW and after DTW of the acquired vibration signals. Later on, the application of FDA highlights the fault frequencies present in the FFT of faulty gears. The result suggests that proposed approach is more effective towards the fault diagnosing with fluctuating speed.

  6. Identification of key factors in Accelerated Low Water Corrosion through experimental simulation of tidal conditions: influence of stimulated indigenous microbiota

    NARCIS (Netherlands)

    Marty, F.; Gueuné, H.; Malard, E.; Sánchez-Amaya, J.M.; Sjögren, L.; Abbas, B.; Quillet, L.; van Loosdrecht, M.C.M.; Muyzer, G.

    2014-01-01

    Biotic and abiotic factors favoring Accelerated Low Water Corrosion (ALWC) on harbor steel structures remain unclear warranting their study under controlled experimental tidal conditions. Initial stimulation of marine microbial consortia by a pulse of organic matter resulted in localized corrosion

  7. Experimental investigation of mixing of non-isothermal water streams at BWR operating conditions

    Energy Technology Data Exchange (ETDEWEB)

    Bergagio, Mattia, E-mail: bergagio@kth.se [AlbaNova University Center, Nuclear Reactor Technology Division, Department of Physics, Royal Institute of Technology, 106 91 Stockholm (Sweden); Anglart, Henryk, E-mail: henryk@kth.se [AlbaNova University Center, Nuclear Reactor Technology Division, Department of Physics, Royal Institute of Technology, 106 91 Stockholm (Sweden); Institute of Heat Engineering, Warsaw University of Technology, 21/25 Nowowiejska Street, 00-665 Warsaw (Poland)

    2017-06-15

    Highlights: • Temperatures are measured in the presence of mixing at BWR operating conditions. • The thermocouple support is moved along a pattern to extend the measurement region. • Uncertainty of 1.58 K for temperatures acquired at 1000 Hz. • Momenta of the hot streams and thermal stratification affect the data examined. • Unconventional spectral analysis is required to further study the data collected. - Abstract: In this experimental investigation, wall surface temperatures have been measured during mixing of three water streams in the annular gap between two coaxial stainless-steel tubes. The inner tube, with an outer diameter of 35 mm and a thickness of 5 mm, holds six K-type, ungrounded thermocouples with a diameter of 0.5 mm, which measured surface temperatures with a sampling rate of either 100 Hz or 1000 Hz. The tube was rotated from 0 to 360° and moved in a range of 387 mm in the axial direction to allow measurements of surface temperatures in the whole mixing region. The outer tube has an inner diameter of 80 mm and a thickness of 10 mm to withstand a water pressure of 9 MPa. A water stream at a temperature of either 333 K or 423 K and a Reynolds number between 1657 and 8410 rose vertically in the annular gap and mixed with two water streams at a temperature of 549 K and a Reynolds number between 3.56 × 10{sup 5} and 7.11 × 10{sup 5}. These two water streams entered the annulus radially on the same axial level, 180° apart. Water pressure was kept at 7.2 MPa. Temperature recordings were performed at five axial and eight azimuthal locations, for each set of boundary conditions. Each recording lasted 120 s to provide reliable data on the variance, intermittency and frequency of the surface temperature time series at hand. Thorough calculations indicate that the uncertainty in the measured temperature is of 1.58 K. The mixing region extends up to 0.2 m downward of the hot inlets. In most cases, measurements indicate non-uniform mixing in the

  8. Verification of Dinamika-5 code on experimental data of water level behaviour in PGV-440 under dynamic conditions

    Energy Technology Data Exchange (ETDEWEB)

    Beljaev, Y.V.; Zaitsev, S.I.; Tarankov, G.A. [OKB Gidropress (Russian Federation)

    1995-12-31

    Comparison of the results of calculational analysis with experimental data on water level behaviour in horizontal steam generator (PGV-440) under the conditions with cessation of feedwater supply is presented in the report. Calculational analysis is performed using DIMANIKA-5 code, experimental data are obtained at Kola NPP-4. (orig.). 2 refs.

  9. Current state of the rearing of replacement young-of-the-year Acipenseriformes in the conditions of the southern Ukraine

    Directory of Open Access Journals (Sweden)

    Ye. Alkhimov

    2017-03-01

    Full Text Available Purpose. Examine and analyze the current state of storage fingerlings acipenseriformes cultivation, including sturgeon and paddlefish, in terms of industrial-experimental Dnieper sturgeon fish-growing factory located in the southern Ukraine. Methodology. The problems were solved by the conventional methods in hydrochemistry, hydrobiology and fish farming. The results were processed using statistical methods of the data processing and analysis which suggest it reliable. Findigs. The research has established that physical and chemical parameters of water in farms' ponds answered the operating pond fishery regulations. The existing level of natural forage base elements can be considered satisfacting for the growing storage material. The best development of zooplankton in the application of polyculture acipenseriformes should be noted. The monoculture benefit was observed in the most fisheries indicators for certain types. Sturgeon fish productivity advantage in terms of polyculture is the evidence of positive mutual influences among the reservoir consumers of different trophic levels. In terms of polyculture the significant benefit of total fish productivity indicator was observed. It clearly points to the prospects of the measure in terms of substantial efficiency of pond areas for growing storage fingerlings. Results of acipenseriformes growing in mono- and polyculture clearly favor the polyculture, which could be used in breeding practice. Scientific Originality. In specific conditions of the southern Ukraine the influence of environmental and technological conditions for growing storage fingerlings acipenseriformes fish (sturgeon and paddlefish was investigated for the first time. In terms of mono- and polyculture cultivation storage acipenseriformes fish material was firstly explored. Practical Value. The results of cultivation can be used in breeding practice as the norm of the environmental situation evaluation in the ponds. Growing storage

  10. CONDICIONES ACTUALES DEL FINANCIAMIENTO DE LAS PYMES COSTARRICENSES. (Current financing conditions for costa rican SME companies

    Directory of Open Access Journals (Sweden)

    Lizette Brenes Bonilla

    2013-09-01

    Full Text Available Uno de los temas indagados en el Segundo estudio nacional realizado por el Observatorio Costarricense de Mipymes durante el 2011 corresponde al financiamiento de las micros, pequeñas y medianas empresas costarricenses. Se consultaron las fuentes de financiamiento más utilizadas, la presentación de solicitudes de crédito durante los últimos cinco años, la utilización que en general hacen estas empresas de los diferentes medios de financiamiento y sus requerimientos actuales. De forma similar a lo que ocurre en otros países, los fondos propios constituyen la principal opción para estas empresas. Por ello, en este trabajo han sido analizadas las condiciones que propician la autofinanciación o el uso de otras opciones. Por medio del análisis estadístico de la información recopilada en la encuesta, se comprueba que algunas variables relativas a la gestión empresarial, tales como la fuente de financiamiento inicial, la experiencia del (de la empresario(a y la prioridad que dan al manejo de aspectos financieros, presentan una asociación significativa con las estrategias de financiamiento en las mipymes costarricenses. ABSTRACT Financing was one of the areas investigated in the Second National Survey of micro, small and medium sized Costa Rican companies during 2011. The most used financing sources, credit applications during the last five years, end use of this credit, and current credit requirements in various financing institutions were investigated. Similar to other countries, own funding was the main option for these companies. Thus, this work examines the conditions that facilitate the use of self financing or other options available. Through statistic analysis of the information collected, variables like initial funding source, previous experience of the entrepreneur and priority given to financial management were shown to present a definite relationship to financing strategies for Costa Rican SMEs.

  11. ABOUT TRACK CIRCUIT CALCULATION METHOD DEPENDENT ON FERROMAGNET PROPERTIES IN CONDITIONS OF TRACTION CURRENT NOISE INFLUENCE

    Directory of Open Access Journals (Sweden)

    A. Yu. Zhuravlev

    2016-02-01

    Full Text Available Purpose. The work is intended to investigate the electromagnetic processes in impedance bond in order to improve noise immunity of track circuits (TC for safe railway operation. Methodology. To achieve this purpose the methods of scientific analysis, mathematical modelling, experimental study, a large-scale simulation were used. Findings. The work examined the interference affecting the normal performance of track circuits. To a large extent, part of track circuit damages account for failures in track circuit equipment. Track circuit equipment is connected directly to the track line susceptible to traction current interference, which causes changes in its electrical characteristics and electromagnetic properties. Normal operability, performance of the main operating modes of the track circuit is determined by previous calculation of its performance and compilation of regulatory tables. The classical method for determination of track circuit parameters was analysed. The classical calculation method assumes representation of individual sections of the electrical track circuit using the quadripole network with known coefficients, usually in the A-form. Determining the coefficients of linear element circuit creates no metrological or mathematical difficulties. However, in circuits containing nonlinear ferromagnets (FM, obtaining the coefficients on the entire induction change range in the cores is quite a difficult task because the classical methods of idling (I and short circuit (SC are not acceptable. This leads to complicated methods for determining both the module and the arguments of quadripole network coefficients. Instead of the classical method, the work proposed the method for calculating the track circuit dependent on nonlinear properties of ferromagnets. Originality. The article examines a new approach to the calculation of TC taking into account the losses in ferromagnets (FM, without determination of equivalent circuit quadripole

  12. Faculty perceptions of the strengths, weaknesses and future prospects of the current medical undergraduate experimental physiology curriculum in Gujarat, India.

    Science.gov (United States)

    Paralikar, Swapnil; Shah, Chinmay

    2015-01-01

    Over the past several years, an opinion has emerged in India that the current practical curricula in medical schools fail to meet many of the objectives for which they were instituted. Hence, this study has assessed the perception of physiology faculty members regarding the current experimental physiology curriculum in one Indian state, Gujarat. The faculty were of the opinion that many of the topics currently taught in experimental physiology (amphibian nerve-muscle and heart muscle experiments) were outdated and clinically irrelevant: Therefore, the faculty advocated that duration of teaching time devoted to some of these topics should be reduced and topics with clinical relevance should be introduced at the undergraduate level. The faculty also felt that more emphasis should be laid on highlighting the clinical aspect related to each concept taught in experimental physiology . Moreover, a majority of faculty members were in favour of replacing the current practice in Gujarat of teaching experimental physiology only by explanation of graphs obtained from experiments conducted in the previous years, with computer assisted learning in small groups.

  13. Experimental study on the optimization of general conditions for a free-flow electrophoresis device with a thermoelectric cooler.

    Science.gov (United States)

    Yan, Jian; Yang, Cheng-Zhang; Zhang, Qiang; Liu, Xiao-Ping; Kong, Fan-Zhi; Cao, Cheng-Xi; Jin, Xin-Qiao

    2014-12-01

    With a given free-flow electrophoresis device, reasonable conditions (electric field strength, carrier buffer conductivity, and flow rate) are crucial for an optimized separation. However, there has been no experimental study on how to choose reasonable general conditions for a free-flow electrophoresis device with a thermoelectric cooler in view of Joule heat generation. Herein, comparative experiments were carried out to propose the selection procedure of general conditions in this study. The experimental results demonstrated that appropriate conditions were (i) electrophoresis separation would be destroyed by bubbles caused by more Joule heating. Additionally, a series of applications under the appropriate conditions were performed with samples of model dyes, proteins (bovine serum albumin, myoglobin, and cytochrome c), and cells (Escherichia coli, Streptococcus thermophilus, and Saccharomyces cerevisiae). The separation results showed that under the appropriate conditions, separation efficiency was obviously better than that in the previous experiments with randomly or empirically selected conditions.

  14. Hydrologic modification to improve habitat in riverine lakes: Management objectives, experimental approach, and initial conditions

    Science.gov (United States)

    Johnson, Barry L.; Barko, John W.; Gerasimov, Yuri; James, William F.; Litvinov, Alexander; Naimo, Teresa J.; Wiener, James G.; Gaugush, Robert F.; Rogala, James T.; Rogers, Sara J.; Schoettger, R.A.

    1996-01-01

    The Finger Lakes habitat-rehabilitation project is intended to improve physical and chemical conditions for fish in six connected back water lakes in Navigation Pool 5 of the upper Missouri River. The primary management objective is to improve water temperature, dissolved oxygen concentration and current velocity during winter for bluegills, Lepomis macrochirus, and black crappies, Pomoxis nigromaculatus, two of the primary sport fishes in the lakes. The lakes will be hydrologically altered by Installing culverts to Introduce controlled flows of oxygenated water into four lakes, and an existing unregulated culvert on a fifth lake will be equipped with a control gate to regulate inflow. These habitat modifications constitute a manipulative field experiment that will compare pre-project (1991 to summer 1993) and post-project (fall 1993 to 1996) conditions in the lakes, including hydrology, chemistry, rooted vegetation, and fish and macroinvertebrate communities. Initial data indicate that the Finger Lakes differ in water chemistry, hydrology, and macrophyte abundance. Macroinvertebrate communities also differed among lakes: species diversity was highest in lakes with dense aquatic macrophytes. The system seems to support a single fish community, although some species concentrated in individual lakes at different times. The introduction of similar flows into five of the lakes will probably reduce the existing physical and chemical differences among lakes. However, our ability to predict the effects of hydrologic modification on fish populations is limited by uncertainties concerning both the interactions of temperature, oxygen and current in winter and the biological responses of primary and secondary producers. Results from this study should provide guidance for similar habitat-rehabilitation projects in large rivers.

  15. Theoretical and Experimental Study of the Primary Current Distribution in Parallel-Plate Electrochemical Reactors

    Science.gov (United States)

    Vazquez Aranda, Armando I.; Henquin, Eduardo R.; Torres, Israel Rodriguez; Bisang, Jose M.

    2012-01-01

    A laboratory experiment is described to determine the primary current distribution in parallel-plate electrochemical reactors. The electrolyte is simulated by conductive paper and the electrodes are segmented to measure the current distribution. Experiments are reported with the electrolyte confined to the interelectrode gap, where the current…

  16. Experimental Phenomena of Improved Ohmic Confinement Induced by Modulated Toroidal Current on the HT-7 Tokamak

    Institute of Scientific and Technical Information of China (English)

    毛剑珊; 罗家融; P.Phillips; 赵君煜; 揭银先; 吴振伟; 胡立群; 李建刚

    2002-01-01

    The phenomena of improved ohmic confinement have been observed during the modulation of the toroidal curranton the Hefei superconducting Tokamak-7 (HT-7). In the experiment, the programming ohmic heating field wasmodulated. A toroidal frequency-modulated current induced by modulated loop voltage was added on the plasmaequilibrium current. The ratio of ac amplitude of the plasma current to the main plasma current is about 12-30%.These improved plasma confinement phenomena include the facts that the average electron density and the centralelectron temperature both increase, the Dα radiation from the edge is reduced, the magnetohydrodynamics isobviously suppressed by oscillating plasma current, eand the global energy confinement time increases by 27-45%o.It is found that the faster the modulation is, the more effective the improved ohmic confinement phase.

  17. Experimental study on directional solidification of Al-Si alloys under the influence of electric currents

    Science.gov (United States)

    Räbiger, D.; Zhang, Y.; Galindo, V.; Franke, S.; Willers, B.; Eckert, S.

    2016-07-01

    The application of electric currents during solidification can cause grain refinement in metallic alloys. However, the knowledge about the mechanisms underlying the decrease in grain size remains fragmentary. This study considers the solidification of Al-Si alloys under the influence of electric currents for the configuration of two parallel electrodes at the free surface. Solidification experiments were performed under the influence of both direct currents (DC) and rectangular electric current pulses (ECP). The interaction between the applied current and its own induced magnetic field causes a Lorentz force which produces an electro-vortex flow. Numerical simulations were conducted to calculate the Lorentz force, the Joule heating and the induced melt flow. The numerical predictions were confirmed by isothermal flow measurements in eutectic GaInSn. The results demonstrate that the grain refining effect observed in our experiments can be ascribed solely to the forced melt flow driven by the Lorentz force.

  18. Experimental evidence of population differences in reproductive investment conditional on environmental stochasticity

    Energy Technology Data Exchange (ETDEWEB)

    Gauthey, Zoé [INRA, UMR 1224, Ecologie Comportementale et Biologie des Populations de Poissons, Aquapôle, quartier Ibarron, 64310 Saint-Pée sur Nivelle (France); Univ Pau & Pays Adour, UMR 1224, Ecologie Comportementale et Biologie des Populations de Poissons, UFR Sciences et Techniques de la Côte Basque, Allée du parc Montaury, 64600 Anglet (France); Panserat, Stéphane [INRA, UR 107, Nutrition Metabolism Aquaculture, Aquapôle, 64310 Saint Pée sur Nivelle (France); Elosegi, Arturo [Faculty of Science and Technology, University of the Basque Country UPV/EHU, 48080 Bilbao (Spain); Herman, Alexandre [INRA, UR 107, Nutrition Metabolism Aquaculture, Aquapôle, 64310 Saint Pée sur Nivelle (France); Tentelier, Cédric [INRA, UMR 1224, Ecologie Comportementale et Biologie des Populations de Poissons, Aquapôle, quartier Ibarron, 64310 Saint-Pée sur Nivelle (France); Univ Pau & Pays Adour, UMR 1224, Ecologie Comportementale et Biologie des Populations de Poissons, UFR Sciences et Techniques de la Côte Basque, Allée du parc Montaury, 64600 Anglet (France); and others

    2016-01-15

    Environmental stochasticity is expected to shape life histories of species, wherein organisms subjected to strong environmental variation should display adaptive response by being able to tune their reproductive investment. For riverine ecosystems, climate models forecast an increase in the frequency and intensity of extreme events such as floods and droughts. The speed and the mechanisms by which organisms may adapt their reproductive investment are therefore of primary importance to understand how species will cope with such radical environmental changes. In the present study, we sampled spawners from two different populations of wild brown trout, originating from two environments with contrasting levels of flow stochasticity. We placed them in sympatry within an experimental channel during reproductive season. In one modality, water flow was maintained constant, whereas in another modality, water flow was highly variable. Reproductive investment of all individuals was monitored using weight and energetic plasma metabolite variation throughout the reproductive season. Only the populations originating from the most variable environment showed a plastic response to experimental manipulation of water flow, the females being able to reduce their weight variation (from 19.2% to 13.1%) and metabolites variations (from 84.2% to 18.6% for triglycerides for instance) under variable flow conditions. These results imply that mechanisms to cope with environmental stochasticity can differ between populations of the same species, where some populations can be plastic whereas other cannot. - Highlights: • We place two populations of brown trout under contrasting water flow for reproduction. • Energetic metabolite variation is used as a cue of reproductive investment. • In constant flow, both populations show the same reproductive investment. • In variable flow, only one of the populations modifies its reproductive investment. • Divergent evolution of reproductive

  19. Inhibition of conditioned stimulus pathway phosphoprotein 24 expression blocks the reduction in A-type transient K+ current produced by one-trial in vitro conditioning of Hermissenda.

    Science.gov (United States)

    Yamoah, Ebenezer N; Levic, Snezana; Redell, John B; Crow, Terry

    2005-05-11

    Long-term intrinsic enhanced excitability is a characteristic of cellular plasticity and learning-dependent modifications in the activity of neural networks. The regulation of voltage-dependent K+ channels by phosphorylation/dephosphorylation and their localization is proposed to be important in the control of cellular plasticity. One-trial conditioning in Hermissenda results in enhanced excitability in sensory neurons, type B photoreceptors, of the conditioned stimulus pathway. Conditioning also regulates the phosphorylation of conditioned stimulus pathway phosphoprotein 24 (Csp24), a cytoskeletal-related protein containing multiple beta-thymosin-like domains. Recently, it was shown that the downregulation of Csp24 expression mediated by an antisense oligonucleotide blocked the development of enhanced excitability in identified type B photoreceptors after one-trial conditioning without affecting short-term excitability. Here, we show using whole-cell patch recordings that one-trial in vitro conditioning applied to isolated photoreceptors produces a significant reduction in the amplitude of the A-type transient K+ current (I(A)) detected 1.5-16 h after conditioning. One-trial conditioning produced a depolarized shift in the steady-state activation curve of I(A) without altering the inactivation curve. The conditioning-dependent reduction in I(A) was blocked by preincubation of the photoreceptors with Csp antisense oligonucleotide. These results provide an important link between Csp24, a cytoskeletal protein, and regulation of voltage-gated ion channels associated with intrinsic enhanced excitability underlying pavlovian conditioning.

  20. Azimuthally asymmetric ring current as a function of Dst and solar wind conditions

    Directory of Open Access Journals (Sweden)

    A. A. Ostapenko

    2004-09-01

    Full Text Available Based on magnetic data, spatial distribution of the westward ring current flowing at |z|<3 RE has been found under five levels of Dst, five levels of the interplanetary magnetic field (IMF z component, and five levels of the solar wind dynamic pressure Psw. The maximum of the current is located near midnight at distances 5 to 7 RE. The magnitude of the nightside and dayside parts of the westward current at distances from 4 to 9 RE can be approximated as Inight=1.75-0.041 Dst, Inoon=0.22-0.013 Dst, where the current is in MA. The relation of the nightside current to the solar wind parameters can be expressed as Inight=1.45-0.20 Bs IMF + 0.32 Psw, where BsIMF is the IMF southward component. The dayside ring current poorly correlates with the solar wind parameters.

  1. Persistent sodium current drives conditional pacemaking in CA1 pyramidal neurons under muscarinic stimulation.

    Science.gov (United States)

    Yamada-Hanff, Jason; Bean, Bruce P

    2013-09-18

    Hippocampal CA1 pyramidal neurons are normally quiescent but can fire spontaneously when stimulated by muscarinic agonists. In brain slice recordings from mouse CA1 pyramidal neurons, we examined the ionic basis of this activity using interleaved current-clamp and voltage-clamp experiments. Both in control and after muscarinic stimulation, the steady-state current-voltage curve was dominated by inward TTX-sensitive persistent sodium current (I(NaP)) that activated near -75 mV and increased steeply with depolarization. In control, total membrane current was net outward (hyperpolarizing) near -70 mV so that cells had a stable resting potential. Muscarinic stimulation activated a small nonselective cation current so that total membrane current near -70 mV shifted to become barely net inward (depolarizing). The small depolarization triggers regenerative activation of I(NaP), which then depolarizes the cell from -70 mV to spike threshold. We quantified the relative contributions of I(NaP), hyperpolarization-activated cation current (I(h)), and calcium current to pacemaking by using the cell's own firing as a voltage command along with specific blockers. TTX-sensitive sodium current was substantial throughout the entire interspike interval, increasing as the membrane potential approached threshold, while both Ih and calcium current were minimal. Thus, spontaneous activity is driven primarily by activation of I(NaP) in a positive feedback loop starting near -70 mV and providing increasing inward current to threshold. These results show that the pacemaking "engine" from I(NaP) is an inherent property of CA1 pyramidal neurons that can be engaged or disengaged by small shifts in net membrane current near -70 mV, as by muscarinic stimulation.

  2. Influence of experimental conditions upon the measurements of hydrogen diffusion in palladium by electrochemical permeation methods

    Energy Technology Data Exchange (ETDEWEB)

    Bucur, R.V.

    1985-01-01

    Influences of electrical parameters, surface roughness, controlled surface contamination and concentration of the electrolyte (NaOH- and H/sub 2/SO/sub 4/-solutions) upon the permeation rate of hydrogen through a palladium membrane (thickness: 5x10/sup -3/ cm) are reported. Diffusion measurements were carried out with an electrochemical permeation cell under transient conditions. The cathodic side of the membrane was subjected either to a constant hydrogen-concentration or hydrogen-flux, while the anodic side was permanently kept at negligibly low hydrogen-concentration. The diffusion coefficient was calculated from the charging and stripping current vs. time curves, by semi-log plots. Reliable and reproducible diffusion coefficient values were obtained both from the charging and stripping curves, under galvanostatic charging conditions. By contrast, reliable values were obtained only from the stripping curves, under potentiostatic charging conditions. Within the temperature range from 5 to 50/sup 0/C the following values have been calculated for hydrogen and deuterium: Dsub(H)/sup 0/=(2.48+-0.40)x10/sup -3/ cm/sup 2/s/sup -1/; Dsub(H)/sup 298/=3.8 . 10/sup -7/ cm/sup 2/s/sup -1/; Esub(H)=5210+-70 cal/mol; Dsub(D)/sup 0/=(1.67+-0.28)x10/sup -3/ cm/sup 2/s/sup -1/; Dsub(D)/sup 298/=4.8 . 10/sup -7/ cm/sup 2/s/sup -1/; Esub(D)=4830+-70 cal/mol. These values agree well with those obtained by non-electrolytical methods.

  3. Modeling Nitrogen Losses in Conventional and Advanced Soil-Based Onsite Wastewater Treatment Systems under Current and Changing Climate Conditions.

    Directory of Open Access Journals (Sweden)

    Ivan Morales

    Full Text Available Most of the non-point source nitrogen (N load in rural areas is attributed to onsite wastewater treatment systems (OWTS. Nitrogen compounds cause eutrophication, depleting the oxygen in marine ecosystems. OWTS rely on physical, chemical and biological soil processes to treat wastewater and these processes may be affected by climate change. We simulated the fate and transport of N in different types of OWTS drainfields, or soil treatment areas (STA under current and changing climate scenarios, using 2D/3D HYDRUS software. Experimental data from a mesocosm-scale study, including soil moisture content, and total N, ammonium (NH4+ and nitrate (NO3- concentrations, were used to calibrate the model. A water content-dependent function was used to compute the nitrification and denitrification rates. Three types of drainfields were simulated: (1 a pipe-and-stone (P&S, (2 advanced soil drainfields, pressurized shallow narrow drainfield (PSND and (3 Geomat (GEO, a variation of SND. The model was calibrated with acceptable goodness-of-fit between the observed and measured values. Average root mean square error (RSME ranged from 0.18 and 2.88 mg L-1 for NH4+ and 4.45 mg L-1 to 9.65 mg L-1 for NO3- in all drainfield types. The calibrated model was used to estimate N fluxes for both conventional and advanced STAs under current and changing climate conditions, i.e. increased soil temperature and higher water table. The model computed N losses from nitrification and denitrification differed little from measured losses in all STAs. The modeled N losses occurred mostly as NO3- in water outputs, accounting for more than 82% of N inputs in all drainfields. Losses as N2 were estimated to be 10.4% and 9.7% of total N input concentration for SND and Geo, respectively. The highest N2 losses, 17.6%, were estimated for P&S. Losses as N2 increased to 22%, 37% and 21% under changing climate conditions for Geo, PSND and P&S, respectively. These findings can provide

  4. Modeling Nitrogen Losses in Conventional and Advanced Soil-Based Onsite Wastewater Treatment Systems under Current and Changing Climate Conditions.

    Science.gov (United States)

    Morales, Ivan; Cooper, Jennifer; Amador, José A; Boving, Thomas B

    2016-01-01

    Most of the non-point source nitrogen (N) load in rural areas is attributed to onsite wastewater treatment systems (OWTS). Nitrogen compounds cause eutrophication, depleting the oxygen in marine ecosystems. OWTS rely on physical, chemical and biological soil processes to treat wastewater and these processes may be affected by climate change. We simulated the fate and transport of N in different types of OWTS drainfields, or soil treatment areas (STA) under current and changing climate scenarios, using 2D/3D HYDRUS software. Experimental data from a mesocosm-scale study, including soil moisture content, and total N, ammonium (NH4+) and nitrate (NO3-) concentrations, were used to calibrate the model. A water content-dependent function was used to compute the nitrification and denitrification rates. Three types of drainfields were simulated: (1) a pipe-and-stone (P&S), (2) advanced soil drainfields, pressurized shallow narrow drainfield (PSND) and (3) Geomat (GEO), a variation of SND. The model was calibrated with acceptable goodness-of-fit between the observed and measured values. Average root mean square error (RSME) ranged from 0.18 and 2.88 mg L-1 for NH4+ and 4.45 mg L-1 to 9.65 mg L-1 for NO3- in all drainfield types. The calibrated model was used to estimate N fluxes for both conventional and advanced STAs under current and changing climate conditions, i.e. increased soil temperature and higher water table. The model computed N losses from nitrification and denitrification differed little from measured losses in all STAs. The modeled N losses occurred mostly as NO3- in water outputs, accounting for more than 82% of N inputs in all drainfields. Losses as N2 were estimated to be 10.4% and 9.7% of total N input concentration for SND and Geo, respectively. The highest N2 losses, 17.6%, were estimated for P&S. Losses as N2 increased to 22%, 37% and 21% under changing climate conditions for Geo, PSND and P&S, respectively. These findings can provide practitioners

  5. The effect of process conditions on the alpha-amylolytic hydrolysis of amylopectin potato starch : an experimental design approach

    NARCIS (Netherlands)

    Marchal, L.M.; Jonkers, J.; Franke, G.T.; Goooijer, de C.D.; Tramper, J.

    1999-01-01

    The hydrolysis of amylopectin potato starch with Bacillus licheniformis α-amylase (Maxamyl) was studied under industrially relevant conditions (i.e. high dry-weight concentrations). The following ranges of process conditions were chosen and investigated by means of an experimental design: pH [5.6-

  6. The effect of process conditions on the alpha-amylolytic hydrolysis of amylopectin potato starch : an experimental design approach

    NARCIS (Netherlands)

    Marchal, L.M.; Jonkers, J.; Franke, G.T.; Goooijer, de C.D.; Tramper, J.

    1999-01-01

    The hydrolysis of amylopectin potato starch with Bacillus licheniformis α-amylase (Maxamyl) was studied under industrially relevant conditions (i.e. high dry-weight concentrations). The following ranges of process conditions were chosen and investigated by means of an experimental design: pH [5.6- 7

  7. Hydrogen sulfide gas emission under turbulent conditions - an experimental approach for free-fall drops.

    Science.gov (United States)

    Matias, N M; Matos, J S; Ferreira, F

    2014-01-01

    Odor nuisance and sulfide corrosion in sewers carrying septic wastewater are accelerated at points of turbulence such as drops in manholes, but accurate methods or empirical expressions to evaluate the gas stripping rate at those particular sites are still missing. With the aim of improving the current knowledge on the influence of free-fall drops on the release of hydrogen sulfide gas, an experimental set-up was built allowing different free-fall drops heights and flows. Three types of experiments were carried out: reaeration tests without sulfide; sulfide oxidation tests; and hydrogen sulfide release tests. With the increase of the free-fall drop height or of the flow, a higher rate of air-to-water mass oxygen transfer was observed. Results regarding sulfide oxidation tests with reaeration through the free-fall have shown that the oxidation rate was correlated with flow. In the hydrogen sulfide release tests, the maximum concentration in the atmosphere reached 500 ppm. Results also showed that increasing the flow rate decreased the time at which the maximum concentrations in the atmosphere were observed.

  8. Experimental study of ELM-like heat loading on beryllium under ITER operational conditions

    Science.gov (United States)

    Spilker, B.; Linke, J.; Pintsuk, G.; Wirtz, M.

    2016-02-01

    The experimental fusion reactor ITER, currently under construction in Cadarache, France, is transferring the nuclear fusion research to the power plant scale. ITER’s first wall (FW), armoured by beryllium, is subjected to high steady state and transient power loads. Transient events like edge localized modes not only deposit power densities of up to 1.0 GW m-2 for 0.2-0.5 ms in the divertor of the machine, but also affect the FW to a considerable extent. Therefore, a detailed study was performed, in which transient power loads with absorbed power densities of up to 1.0 GW m-2 were applied by the electron beam facility JUDITH 1 on beryllium specimens at base temperatures of up to 300 °C. The induced damage was evaluated by means of scanning electron microscopy and laser profilometry. As a result, the observed damage was highly dependent on the base temperatures and absorbed power densities. In addition, five different classes of damage, ranging from ‘no damage’ to ‘crack network plus melting’, were defined and used to locate the damage, cracking, and melting thresholds within the tested parameter space.

  9. Experimentally-Based Computational Investigation into Beat-To-Beat Variability in Ventricular Repolarization and Its Response to Ionic Current Inhibition.

    Directory of Open Access Journals (Sweden)

    E Pueyo

    Full Text Available Beat-to-beat variability in repolarization (BVR has been proposed as an arrhythmic risk marker for disease and pharmacological action. The mechanisms are unclear but BVR is thought to be a cell level manifestation of ion channel stochasticity, modulated by cell-to-cell differences in ionic conductances. In this study, we describe the construction of an experimentally-calibrated set of stochastic cardiac cell models that captures both BVR and cell-to-cell differences in BVR displayed in isolated canine action potential measurements using pharmacological agents. Simulated and experimental ranges of BVR are compared in control and under pharmacological inhibition, and the key ionic currents determining BVR under physiological and pharmacological conditions are identified. Results show that the 4-aminopyridine-sensitive transient outward potassium current, Ito1, is a fundamental driver of BVR in control and upon complete inhibition of the slow delayed rectifier potassium current, IKs. In contrast, IKs and the L-type calcium current, ICaL, become the major contributors to BVR upon inhibition of the fast delayed rectifier potassium current, IKr. This highlights both IKs and Ito1 as key contributors to repolarization reserve. Partial correlation analysis identifies the distribution of Ito1 channel numbers as an important independent determinant of the magnitude of BVR and drug-induced change in BVR in control and under pharmacological inhibition of ionic currents. Distributions in the number of IKs and ICaL channels only become independent determinants of the magnitude of BVR upon complete inhibition of IKr. These findings provide quantitative insights into the ionic causes of BVR as a marker for repolarization reserve, both under control condition and pharmacological inhibition.

  10. Experimental evaluation of IGBT junction temperature measurement via peak gate current

    DEFF Research Database (Denmark)

    Baker, Nick; Munk-Nielsen, Stig; Iannuzzo, Francesco

    2015-01-01

    Temperature sensitive electrical parameters allow junction temperature measurements on power semiconductors without modification to module packaging. The peak gate current has recently been proposed for IGBT junction temperature measurement and relies on the temperature dependent resistance of th...

  11. Currents, HF Radio-derived, Monterey Bay, 25 hr, Meridional, EXPERIMENTAL

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The data is the 25 hour running average of the meridional component of ocean surface currents derived from High Frequency Radio-derived measurements. THIS IS AN...

  12. Currents, HF Radio-derived, Ano Nuevo, Normal Model, Meridional, EXPERIMENTAL

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The data is the meridional component of ocean surface currents derived from High Frequency Radio-derived measurements, with missing values filled in by a normal...

  13. Currents, HF Radio-derived, SF Bay Outlet, 25 hr, Zonal, EXPERIMENTAL

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The data is the 25 hour running average of the zonal component of ocean surface currents derived from High Frequency Radio-derived measurements. THIS IS AN...

  14. Currents, HF Radio-derived, SF Bay, 33 hr, Meridional, EXPERIMENTAL

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The data is the 33 hour running average of the meridional component of ocean surface currents derived from High Frequency Radio-derived measurements. THIS IS AN...

  15. Currents, HF Radio-derived, Bodega Bay, 25 hr, Zonal, EXPERIMENTAL

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The data is the 25 hour running average of the zonal component of ocean surface currents derived from High Frequency Radio-derived measurements. THIS IS AN...

  16. Currents, HF Radio-derived, Ano Nuevo, 25 hr, Meridional, EXPERIMENTAL

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The data is the 25 hour running average of the meridional component of ocean surface currents derived from High Frequency Radio-derived measurements. THIS IS AN...

  17. Currents, HF Radio-derived, Ano Nuevo, Normal Model, Zonal, EXPERIMENTAL

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The data is the zonal component of ocean surface currents derived from High Frequency Radio-derived measurements, with missing values filled in by a normal model....

  18. Currents, HF Radio-derived, Ano Nuevo, 25 hr, Zonal, EXPERIMENTAL

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The data is the 25 hour running average of the zonal component of ocean surface currents derived from High Frequency Radio-derived measurements. THIS IS AN...

  19. Currents, HF Radio-derived, SF Bay Outlet, Normal Model, Zonal, EXPERIMENTAL

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The data is the zonal component of ocean surface currents derived from High Frequency Radio-derived measurements, with missing values filled in by a normal model....

  20. Experimental pain processing in individuals with cognitive impairment: current state of the science

    DEFF Research Database (Denmark)

    Defrin, R; Amanzio, Martina; de Tomasso, M

    2015-01-01

    to cognitively unimpaired individuals. Our current understanding of the neurobiological mechanisms underpinning these alterations is limited, but may be enhanced through the use of animal models of CI which also exhibit alterations in nociceptive responding. Further research employing additional behavioural...

  1. Currents, HF Radio-derived, Monterey Bay, Normal Model, Zonal, EXPERIMENTAL

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The data is the zonal component of ocean surface currents derived from High Frequency Radio-derived measurements, with missing values filled in by a normal model....

  2. Currents, HF Radio-derived, Monterey Bay, Normal Model, Meridional, EXPERIMENTAL

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The data is the meridional component of ocean surface currents derived from High Frequency Radio-derived measurements, with missing values filled in by a normal...

  3. Currents, HF Radio-derived, SF Bay Outlet, 25 hr, Meridional, EXPERIMENTAL

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The data is the 25 hour running average of the meridional component of ocean surface currents derived from High Frequency Radio-derived measurements. THIS IS AN...

  4. Currents, HF Radio-derived, Bodega Bay, 25 hr, Meridional, EXPERIMENTAL

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The data is the 25 hour running average of the meridional component of ocean surface currents derived from High Frequency Radio-derived measurements. THIS IS AN...

  5. Currents, HF Radio-derived, Monterey Bay, 25 hr, Zonal, EXPERIMENTAL

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The data is the 25 hour running average of the zonal component of ocean surface currents derived from High Frequency Radio-derived measurements. THIS IS AN...

  6. Currents, HF Radio-derived, SF Bay Outlet, Normal Model, Meridional, EXPERIMENTAL

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The data is the meridional component of ocean surface currents derived from High Frequency Radio-derived measurements, with missing values filled in by a normal...

  7. Experimental determination about thermal comfort conditions in buildings; Determinacion experimental de las condiciones de confort termico en edificaciones

    Energy Technology Data Exchange (ETDEWEB)

    Ambriz Garcia, Juan Jose; Garcia Chavez, Jose Roberto; Paredes Rubio, Hernando Romero [Universidad Autonoma Metropolitana (Mexico)]. E-mail: agj@xanum.uam.mx; jgc@correo.azc.uam.mx; hrp@xanum.uam.mx

    2006-04-15

    This paper analyzes the thermal comfort importance in a building. And the influence it exerts on quality of life as well as the efficiency of people work activities. There are comments about some models which better help to estimate the recommended temperature levels. The experimental evaluation results from a Mexico City population sampler are presented. This work was done in a Controlled Environment Laboratory; the obtained outcomes proved the preferences occupants exceed the comfort zone greatest limit accepted in the reference international standards. The meaning of this conclusion is thermal comfort can be reached with higher temperatures and consequently an energy consumption and an environment impact decrease. [Spanish] En este trabajo se analiza la importancia que tiene el confort termico en la calidad de vida de las personas que ocupan una edificacion y en la eficiencia de sus actividades. Se comentan algunos modelos con los cuales se estiman los niveles de temperatura recomendados y se presentan los resultados de una evaluacion experimental realizada en un Laboratorio de Ambiente Controlado con una muestra de la poblacion del Distrito Federal. Los resultados que se obtuvieron demuestran que los ocupantes tienen preferencias que rebasan el limite superior de la zona de confort comunmente aceptada en los estandares internacionales de referencia. Esto quiere decir que el confort puede lograrse con mayores temperaturas, lo que se traduce en menor consumo de energia y menor impacto en el ambiente.

  8. Decoupled Double Synchronous Reference Frame Current Controller for Unbalanced Grid Voltage Conditions

    DEFF Research Database (Denmark)

    Reyes, M.; Rodriguez, Pedro; Vazquez, S.;

    2012-01-01

    -sequence current components is becoming necessary for achieving new capabilities like the reactive power injection during a grid fault. This paper deals with a fundamental issue in this topic, i.e., the performance of the current controller. Classical dq controllers, which are extensively used in industrial...

  9. Single-Case Experimental Designs: A Systematic Review of Published Research and Current Standards

    Science.gov (United States)

    Smith, Justin D.

    2012-01-01

    This article systematically reviews the research design and methodological characteristics of single-case experimental design (SCED) research published in peer-reviewed journals between 2000 and 2010. SCEDs provide researchers with a flexible and viable alternative to group designs with large sample sizes. However, methodological challenges have…

  10. Collecting conditions usage metadata to optimize current and future ATLAS software and processing

    CERN Document Server

    Barberis, Dario; The ATLAS collaboration

    2017-01-01

    Conditions data (for example: alignment, calibration, data quality) are used extensively in the processing of real and simulated data in ATLAS. The volume and variety of the conditions data needed by different types of processing are quite diverse, so optimizing its access requires a careful understanding of conditions usage patterns. These patterns can be quantified by mining representative log files from each type of processing and gathering detailed information about conditions usage for that type of processing into a central repository. \\end{abstract}

  11. Evaporation from soils under diurnal boundary conditions: Experimental and modeling investigation to evaluate Non-equilibrium-based approaches

    Science.gov (United States)

    Trautz, Andrew; Smits, Kathleen; Cihan, Abdullah; Illangasekare, Tissa

    2013-04-01

    Evaporation from bare soil is a key component of the hydrologic cycle and the process primarily responsible for governing water and energy exchanges between the land and atmosphere. Despite its importance, there is still a great deal of uncertainty associated with our current understanding of this complex multiphase phenomenon. A common approach when modeling the movement of liquid water, water vapor and heat in the soil immediately below the land-atmosphere interface is to assume that water vapor concentration in air is always in equilibrium with liquid water. However, this equilibrium assumption is called into question by experiments about liquid/gas phase change in porous media suggesting that the equilibrium establishment is not instantaneous; a volatilization or condensation time is observed at the macroscopic scale under certain conditions. Introduction of such a non-equilibrium mass transfer relationship is based on the Hertz-Knudsen equation (HKE) derived from the kinetic theory of gases. Multiple formulations have been presented to represent the rate of phase change between water and vapor, many relying on empirical fitting parameters due to limited experimental data. The purpose of this work is to perform an unbiased comparison between various conceptual and mathematical formulations for non-equilibrium phase change on evaporation and develop appropriate numerical models to be used in simulations. The key to such a comparison is the availability of accurate data. As such data at the scale of interest is not possible to obtain in field settings, a unique two-dimensional cell apparatus was developed. The test cell was equipped with a network of sensors for automated and continuous monitoring of soil moisture, soil and air temperature and relative humidity, and wind velocity to generate precision data. A fully-coupled numerical model to solve the governing equations for heat, liquid water and water vapor transport in soil was developed. The code implements a

  12. A High Temperature Experimental Characterization Procedure for Oxide-Based Thermoelectric Generator Modules under Transient Conditions

    Directory of Open Access Journals (Sweden)

    Elena Anamaria Man

    2015-11-01

    Full Text Available The purpose of this study is to analyze the steady-state and transient behavior of the electrical and thermal parameters of thermoelectric generators (TEGs. The focus is on the required wait-time between measurements in order to reduce measurement errors which may appear until the system reaches steady-state. By knowing this waiting time, the total characterization time can also be reduced. The experimental characterization process is performed on a test rig known as TEGeta, which can be used to assess the output characteristics of TEG modules under different load values and temperature conditions. The setup offers the possibility to control the hot side temperature up to 1000 °C with a load variation range value between 0.22–8.13 Ω. A total of ten thermocouples are placed in the setup with the purpose of measuring the temperature in specific points between the heater and the heat sink. Based on the readings, the temperature on the hot and cold side of the modules can be extrapolated. This study provides quantitative data on the minimum waiting time of the temperatures in the surrounding system to reach equilibrium. Laboratory tests are performed on a calcium-manganese oxide module at temperatures between 400 and 800 °C to explore the high temperatures features of the setup.

  13. Influence of experimental conditions on data variability in the liver comet assay.

    Science.gov (United States)

    Guérard, M; Marchand, C; Plappert-Helbig, U

    2014-03-01

    The in vivo comet assay has increasingly been used for regulatory genotoxicity testing in recent years. While it has been demonstrated that the experimental execution of the assay, for example, electrophoresis or scoring, can have a strong impact on the results; little is known on how initial steps, that is, from tissue sampling during necropsy up to slide preparation, can influence the comet assay results. Therefore, we investigated which of the multitude of steps in processing the liver for the comet assay are most critical. All together eight parameters were assessed by using liver samples of untreated animals. In addition, two of those parameters (temperature and storage time of liver before embedding into agarose) were further investigated in animals given a single oral dose of ethyl methanesulfonate at dose levels of 50, 100, and 200 mg/kg, 3 hr prior to necropsy. The results showed that sample cooling emerged as the predominant influence factor, whereas variations in other elements of the procedure (e.g., size of the liver piece sampled, time needed to process the liver tissue post-mortem, agarose temperature, or time of lysis) seem to be of little relevance. Storing of liver samples of up to 6 hr under cooled conditions did not cause an increase in tail intensity. In contrast, storing the tissue at room temperature, resulted in a considerable time-dependent increase in comet parameters.

  14. Evolution of fracture permeability of ultramafic rocks undergoing serpentinization at hydrothermal conditions: An experimental study

    Science.gov (United States)

    Farough, Aida; Moore, Diane E.; Lockner, David A.; Lowell, R. P.

    2016-01-01

    We performed flow-through laboratory experiments on five cylindrically cored samples of ultramafic rocks, in which we generated a well-mated through-going tensile fracture, to investigate evolution of fracture permeability during serpentinization. The samples were tested in a triaxial loading machine at a confining pressure of 50 MPa, pore pressure of 20 MPa, and temperature of 260°C, simulating a depth of 2 km under hydrostatic conditions. A pore pressure difference of up to 2 MPa was imposed across the ends of the sample. Fracture permeability decreased by 1–2 orders of magnitude during the 200–330 h experiments. Electron microprobe and SEM data indicated the formation of needle-shaped crystals of serpentine composition along the walls of the fracture, and chemical analyses of sampled pore fluids were consistent with dissolution of ferro-magnesian minerals. By comparing the difference between fracture permeability and matrix permeability measured on intact samples of the same rock types, we concluded that the contribution of the low matrix permeability to flow is negligible and essentially all of the flow is focused in the tensile fracture. The experimental results suggest that the fracture network in long-lived hydrothermal circulation systems can be sealed rapidly as a result of mineral precipitation, and generation of new permeability resulting from a combination of tectonic and crystallization-induced stresses is required to maintain fluid circulation.

  15. Experimental Study on Interfacial Area Transport of Two-Phase Flow under Vibration Conditions

    Directory of Open Access Journals (Sweden)

    Xiu Xiao

    2017-01-01

    Full Text Available An experimental study on air-water two-phase flow under vibration condition has been conducted using double-sensor conductivity probe. The test section is an annular geometry with hydraulic diameter of 19.1 mm. The vibration frequency ranges from 0.47 Hz to 2.47 Hz. Local measurements of void fraction, interfacial area concentration (IAC, and Sauter mean diameter have been performed along one radius in the vibration direction. The result shows that local parameters fluctuate continuously around the base values in the vibration cycle. Additional bubble force due to inertia is used to explain lateral bubble motions. The fluctuation amplitudes of local void fraction and IAC increase significantly with vibration frequency. The radial distribution of local parameters at the maximum vibration displacement is specifically analyzed. In the void fraction and IAC profiles, the peak near the inner wall is weakened or even disappearing and a strong peak skewed to outer wall is gradually observed with the increase of vibration frequency. The nondimensional peak void fraction can reach a maximum of 49% and the mean relative variation of local void fraction can increase to more than 29% as the vibration frequency increases to 2.47 Hz. But the increase of vibration frequency does not bring significant change to bubble diameter.

  16. Mass changes accompanying the pseudocapacitance of hydrous RuO{sub 2} under different experimental conditions

    Energy Technology Data Exchange (ETDEWEB)

    Sopcic, Suzana; Rokovic, Marijana Kraljic [Faculty of Chemical Engineering and Technology, Department of Electrochemistry, University of Zagreb, Marulicev trg 19, HR-10000 Zagreb (Croatia); Mandic, Zoran, E-mail: zmandic@fkit.h [Faculty of Chemical Engineering and Technology, Department of Electrochemistry, University of Zagreb, Marulicev trg 19, HR-10000 Zagreb (Croatia); Roka, Andras [Department of Physical Chemistry, Eoetvoes Lorand University, Pazmany Peter setany 1/A, H-1117 Budapest (Hungary); Inzelt, Gyoergy, E-mail: inzeltgy@chem.elte.h [Department of Physical Chemistry, Eoetvoes Lorand University, Pazmany Peter setany 1/A, H-1117 Budapest (Hungary)

    2011-04-01

    Pseudocapacitance reaction of hydrous ruthenium oxide was investigated by cyclic voltammetry combined with electrochemical quartz-crystal nanobalance (EQCN) in sulfuric acid as well as in neutral solutions of Na{sub 2}SO{sub 4} and K{sub 2}SO{sub 4}. The ruthenium oxide electrode was prepared by attaching the ruthenium oxide particles on gold covered quartz electrode. The results show that there are different types of charge taking place simultaneously during the redox reaction of ruthenium oxide electrode. Their contribution to the overall charge depends on the experimental conditions. Depending on the potential and electrolyte used the redox reaction of ruthenium oxide is accompanied either by mass loss or by mass gain. The average molar masses of the species exchanged between the solid phase and the electrolyte solution depend on the potential and scan rate. The effect of Nafion{sup TM} top layer was also investigated. It has been found that it does not affect significantly the overall specific capacitance of ruthenium oxide electrode but the apparent molar masses of exchanged species decrease in comparison with the uncovered electrodes.

  17. TWSME of a NiTi strip in free bending conditions: experimental and theoretical approach

    Directory of Open Access Journals (Sweden)

    A. Fortini

    2014-07-01

    Full Text Available This paper deals with the two-way shape memory effect (TWSME induced on a strip of a nearequiatomic NiTi alloy by means of the shape memory cycling training method. This procedure is based on the deformation in martensite state to reach the desired cold shape followed by cycling the temperature from above Af to below Mf. To this end, the sample was thermally treated to memorise a bent shape, thermomechanical trained as described and thermally cycled in unloaded conditions in order to study the stability of the induced TWSME. Heating to Af was reached by a hot air stream flow whereas cooling to Mf was achieved through natural convection. The evolution of the curvature with the increasing number of cycles was evaluated. The thermomechanical behaviour of the strip undergoing uniform bending was simulated using a one-dimensional phenomenological model based on stress and the temperature as external control variables. Both martensite and austenite volume fractions were chosen as internal parameters and kinetic laws were used in order to describe their evolution during phase transformations. The experimental findings are compared with the model simulation and a numerical prediction based on the approach proposed in [25].

  18. Experimental Setup for Determining Ammonia-Salt Adsorption and Desorption Behavior Under Typical Heat Pump Conditions. Experimental Results

    Energy Technology Data Exchange (ETDEWEB)

    Van der Pal, M.; De Boer, R.; Veldhuis, J.B.J. [ECN Biomass and Energy Efficiency, Petten (Netherlands)

    2013-09-15

    For the aim of obtaining a better understanding of the performance of a salt-ammonia sorption reactor/heat exchanger a new test-rig was developed. This test-rig enables the measurement of the performance in adsorption and desorption mode of different sorption reactor designs. It measures the speed of uptake and release of ammonia gas of various salt-ammonia reactions under well-controlled and well-monitored process conditions, similar to the heat pump conditions. The test-rig measures the ammonia uptake and release under controlled pressure and temperature conditions. Temperatures of the salt reactor can be varied from ambient temperature up to 200{sup o}C and the ammonia pressure can be varied between 0.02 to 2 MPa. These conditions can be set independently and repeated at regular time-intervals. Besides NH3-mass-flow meters, pressure and temperature sensors, the setup also contains an endoscope to observe any macroscopic structural changes in the material during uptake and release of ammonia. Measurements so far have shown a liquid phase of LiCl.3NH3 at pressures of 0.5 MPa and temperatures exceeding 90{sup o}C. Voilent foaming is observed at 120{sup o}C resulting in salt losses. A correlation was determined between the reaction rate of MgCl{sub 2}(2-6)NH3 and the relative pressure gradient yielding a reaction time of about 1500 seconds for a relative pressure difference of 1. Multiple sorption cycles of the CaCl{sub 2}(2-4)NH3 reaction, showed a reduced activity from 85% of the theoretical maximum sorbed mass at the first sorption cycle, to 15% after 300+ cycles.

  19. Transcranial direct-current stimulation induced in stroke patients with aphasia: a prospective experimental cohort study

    Directory of Open Access Journals (Sweden)

    Michele Devido Santos

    Full Text Available CONTEXT AND OBJECTIVE: Previous animal and human studies have shown that transcranial direct current stimulation can induce significant and lasting neuroplasticity and may improve language recovery in patients with aphasia. The objective of the study was to describe a cohort of patients with aphasia after stroke who were treated with transcranial direct current stimulation. DESIGN AND SETTING: Prospective cohort study developed in a public university hospital. METHODS: Nineteen patients with chronic aphasia received 10 transcranial direct current stimulation sessions lasting 20 minutes each on consecutive days, using a current of 2 mA. The anode was positioned over the supraorbital area and the cathode over the contralateral motor cortex. The following variables were analyzed before and after the 10 neuromodulation sessions: oral language comprehension, copying, dictation, reading, writing, naming and verbal fluency. RESULTS: There were no adverse effects in the study. We found statistically significant differences from before to after stimulation in relation to simple sentence comprehension (P = 0.034, naming (P = 0.041 and verbal fluency for names of animals (P = 0.038. Improved scores for performing these three tasks were seen after stimulation. CONCLUSIONS: We observed that excitability of the primary motor cortex through transcranial direct current stimulation was associated with effects on different aspects of language. This can contribute towards future testing in randomized controlled trials.

  20. Experimental data and boundary conditions for a Double - Skin Facade building in preheating mode

    DEFF Research Database (Denmark)

    Larsen, Olena Kalyanova; Heiselberg, Per; Jensen, Rasmus Lund

    Frequent discussions of double skin façade energy performance have started a dialogue about the methods, models and tools for simulation of double façade systems and reliability of their results. Their reliability will increase with empirical validation of the software. Detailed experimental work...... with all information about the experimental data and measurements, necessary to complete an independent empirical validation of any simulation tool. The article includes detailed information about the experimental apparatus, experimental principles and experimental full-scale test facility ‘The Cube...

  1. Experimental data and boundary conditions for a Double - Skin Facade building in transparent insulation mode

    DEFF Research Database (Denmark)

    Larsen, Olena Kalyanova; Heiselberg, Per; Jensen, Rasmus Lund

    Frequent discussions of double skin façade energy performance have started a dialogue about the methods, models and tools for simulation of double façade systems and reliability of their results. Their reliability will increase with empirical validation of the software. Detailed experimental work...... with all information about the experimental data and measurements, necessary to complete an independent empirical validation of any simulation tool. The article includes detailed information about the experimental apparatus, experimental principles and experimental full-scale test facility ‘The Cube...

  2. Minimum quench power dissipation and current non-uniformity in ITER type NbTi cable-in-conduit conductor samples under DC conditions

    CERN Document Server

    Rolando, G; Nijhuis, A

    2011-01-01

    The level of current non-uniformity in NbTi CICCs sections near the joints in combination with the magnet field profile needs attention in view of proper joint design. The strand Joule power and current distribution at quench under DC conditions of two samples of ITER Poloidal Field Coil conductors, as tested in the SULTAN facility and of the so called PFCI Model Coil Insert, have been analyzed with the numerical cable model JackPot. The precise trajectories of all individual strands, joint design, cabling configuration, spatial distribution of the magnetic field, sample geometry and using experimentally determined interstrand resistance distributions have been taken into account. Although unable to predict the quench point due to the lack of a thermal-hydraulic routine, the model allows to assess the instantaneous strand power at quench and its local distribution in the cable, showing the hot spots, once the quench conditions in terms of current and temperature are experimentally known., The analysis points ...

  3. Single-Case Experimental Design: Current Standards and Applications in Occupational Therapy.

    Science.gov (United States)

    Lane, Justin D; Ledford, Jennifer R; Gast, David L

    Occupational therapy is a field with a long-standing history of recommending and implementing interventions designed to improve the quality of life of clients with disabilities. Often, the interventions are individualized to meet the needs of this diverse group of clients in dynamic settings. Identifying effective and efficient interventions for such a diverse group of clients and settings requires a flexible research approach. Single-case experimental designs (SCEDs) allow practitioners and researchers to answer experimental questions within the context of rigorous research designs. The purpose of this article is to highlight the similarities between the mission of occupational therapy and SCEDs. Recommendations for designing single-case studies with the framework provided by the Single-Case Reporting Guideline in Behavioral Interventions are provided. In addition, common problems and proposed solutions, along with implications for practitioners and researchers, are provided. Copyright © 2017 by the American Occupational Therapy Association, Inc.

  4. The case for a directional dark matter detector and the status of current experimental efforts

    CERN Document Server

    Ahlen, S; Battat, J B R; Billard, J; Bozorgnia, N; Burgos, S; Caldwell, T; Carmona, J M; Cebrián, S; Colas, P; Dafni, T; Daw, E; Dujmic, D; Dushkin, A; Fedus, W; Ferrer, E; Finkbeiner, D; Fisher, P H; Forbes, J; Fusayasu, T; Galan, J; Gamble, T; Ghag, C; Giomataris, Yu; Gold, M; Gomez, H; Gómez, M E; Gondolo, P; Green, A; Grignon, C; Guillaudin, O; Hagemann, C; Hattori, K; Henderson, S; Higashi, N; Ida, C; Iguaz, F J; Inglis, A; Irastorza, I G; Iwaki, S; Kaboth, A; Kabuki, S; Kadyk, J; Kallivayalil, N; Kubo, H; Kurosawa, S; Kudryavtsev, V A; Lamy, T; Lanza, R; Lawson, T B; Lee, A; Lee, E R; Lin, T; Loomba, D; López, J; Luzón, G; Manobu, T; Martoff, J; Mayet, F; McCluskey, B; Miller, E; Miuchi, K; Monroe, J; Morgan, B; Muna, D; Murphy, A St J; Naka, T; Nakamura, K; Nakamura, M; Nakano, T; Nicklin, G G; Nishimura, H; Niwa, K; Paling, S M; Parker, J; Petkov, A; Pipe, M; Pushkin, K; Robinson, M; Rodríguez, A; Rodríguez-Quintero, J; Sahin, T; Sanderson, R; Sanghi, N; Santos, D; Sato, O; Sawano, T; Sciolla, G; Sekiya, H; Slatyer, T R; Snowden-Ifft, D P; Spooner, N J C; Sugiyama, A; Takada, A; Takahashi, M; Takeda, A; Tanimori, T; Taniue, K; Tomas, A; Tomita, H; Tsuchiya, K; Turk, J; Tziaferi, E; Ueno, K; Vahsen, S; Vanderspek, R; Vergados, J; Villar, J A; Wellenstein, H; Wolfe, I; Yamamoto, R K; Yegoryan, H

    2010-01-01

    We present the case for a dark matter detector with directional sensitivity. This document was developed at the 2009 CYGNUS workshop on directional dark matter detection, and contains contributions from theorists and experimental groups in the field. We describe the need for a dark matter detector with directional sensitivity; each directional dark matter experiment presents their project's status; and we close with a feasibility study for scaling up to a one ton directional detector, which would cost around $150M.

  5. Experimental Test of Alternating-Current Zeeman Interference Effect in Ramsey Separated Oscillating Fields

    Institute of Scientific and Technical Information of China (English)

    ZHANG Jun-Hai; WANG Feng-Zhi; YANG Dong-Hai

    2004-01-01

    An experimental test of ac Zeeman effect in an optically pumped caesium beam frequency standard is reported and analysed. An interference pattern of the atomic energy level shift as a function of the applied microwave field near the atomic transition frequency was observed. It was superimposed on the dispersion lineshape of a normal ac Zeeman effect. This effect was analysed with the atomic wavefunction phase analysing method.

  6. A study of experimental evaluations of neural network learning algorithms: current research practice

    OpenAIRE

    Prechelt, Lutz

    2007-01-01

    113 articles about neural network learning algorithms published in 1993 and 1994 are examined for the amount of experimental evaluation they contain. Every third of them does employ not even a single realistic or real learning problem. Only 6% of all articles present results for more than one problem using real world data.Furthermore, one third of all articles does not present any quantitative comparison with a previously known algorithm. These results indicate that the q...

  7. Current Limiting Performance of Three-Phase Concentric Transformer Type SFCL at Unbalanced Fault Conditions

    OpenAIRE

    Shirai, Yasuyuki; Noda, Syo; Yamabe, Kenta; Hattori, Keisuke; Baba, Jumpei; Nishihara, Taichi; Nitta, Tanzo; Kobayashi, Shinichi; Sato, Kenichi

    2013-01-01

    We have proposed a transformer type SFCL whose primary and secondary superconducting coils have rewound structure. The primary coil is connected to a power line. The secondary one is short-circuited and has fewer turns than the primary coil. For small fault current, only the secondary coil turns to normal state. Inductive component of impedance at the primary terminal mainly appears. For larger fault current, the primary coil also turns to normal state, resistive component additively appears....

  8. Surface current dynamics under sea breeze conditions observed by simultaneous HF radar, ADCP and drifter measurements

    Science.gov (United States)

    Sentchev, Alexei; Forget, Philippe; Fraunié, Philippe

    2017-02-01

    Ocean surface boundary layer dynamics off the southern coast of France in the NW Mediterranean is investigated by using velocity observations by high-frequency (HF) radars, surface drifting buoys and a downward-looking drifting acoustic Doppler current profiler (ADCP). The analysis confirms that velocities measured by HF radars correspond to those observed by an ADCP at the effective depth z f = k -1, where k is wavenumber of the radio wave emitted by the radar. The radials provided by the radars were in a very good agreement with in situ measurements, with the relative errors of 1 and 9 % and root mean square (RMS) differences of 0.02 and 0.04 m/s for monostatic and bistatic radar, respectively. The total radar-based velocities appeared to be slightly underestimated in magnitude and somewhat biased in direction. At the end of the survey period, the difference in the surface current direction, based on HF radar and ADCP data, attained 10°. It was demonstrated that the surface boundary layer dynamics cannot be reconstructed successfully without taking into the account velocity variation with depth. A significant misalignment of ˜30° caused by the sea breeze was documented between the HF radar (HFR-derived) surface current and the background current. It was also found that the ocean response to a moderate wind forcing was confined to the 4-m-thick upper layer. The respective Ekman current attained the maximum value of 0.15 m/s, and the current rotation was found to be lagging the wind by approximately 40 min, with the current vector direction being 15-20° to the left of the wind. The range of velocity variability due to wind forcing was found comparable with the magnitude of the background current variability.

  9. [Current situation of the research on living conditions and health status of elderly people in Spain].

    Science.gov (United States)

    Machón-Sobrado, Mónica; Vergara-Mitxeltorena, Itziar; Dorronsoro-Iraeta, Miren; Larrañaga-Larrañaga, Nerea; Vrotsou, Kalliopi; Larrañaga-Padilla, Isabel

    2016-01-01

    To analyse the dimensions studied with respect to living and health conditions of the non-institutionalised elderly in the scientific literature in Spain. A content analysis based on secondary sources was carried out by literature searches in Pubmed and Embase in Spanish and English. The search strategies combined terms related to older people, health and/or living conditions and with Spain. All studies assessing living and/or health conditions of elderly in Spain were included. Studies analyzing a specific aspect of living or health conditions and those based on institutionalized population were excluded. A total of 14 studies were considered in the content analysis. The studies are usually local, cross-sectional and data collection is done by direct interview. Variability was observed in the aspects analysed about living and health conditions. All studies included: sociodemographic characteristics, health status and lifestyle habits. Issues related to the status of the out-of home environment are poorly analysed. This work allows knowing the dimensions prioritised in the studies carried out to date about health and living conditions in Spain. It also provides key elements for the development of future research aiming to integrate both living and health conditions of elderly population, both aspects closely related. Copyright © 2015 Elsevier España, S.L.U. All rights reserved.

  10. MECHANISMS OF MELATONIN EFFECTS UPON IMMUNE STATE IN EXPERIMENTAL DESYNCHRONOSES PRODUCED UNDER THE LED ILLUMINATION CONDITIONS

    Directory of Open Access Journals (Sweden)

    M. V. Osikov

    2015-01-01

    Full Text Available Disorders of immune state in desynchronosis may be associated with reduced concentrations of melatonin in blood, thus being a prerequisite for pharmacological correction of appropriate homeostatic changes. The purpose of this work was to explore some mechanisms of exogenous melatonin actions upon parameters of innate and adaptive immunity in experimental model of desynchronosis under the conditions of LED illumination. The study was performed with 196 adult guinea pigs. Light desynchronosis was produced by day-and-night illumination of the animals having been continued for 30 days. Melatonin was administered applied per os daily at the total dose of 30 mg/kg. A solution of melatonin in isotonic NaCl solution was prepared from the Melaxen drug (INN: melatonin, “Unipharm Inc.,” USA ex tempore. To study innate immunity of blood cells, we determined leukocyte numbers, WBC differential counts, and functional activity of phagocytes, as spontaneous and induced NBT test, as well as engulfment of polystyrene latex particles. Th1-specific immune response was studied according to degree of delayed type hypersensitivity reaction; Th2-dependent response was assessed as the numbers of antibody-forming cells in the spleen of the animals after immunization with allogeneic erythrocytes. Serum concentrations of interleukin 4 (IL-4, interferon-gamma (IFNγ, melatonin, and cortisol were measured by enzyme immunoassay, using the “Immulayt 2000” (USA with guinea pigspecific test systems. It was found that experimental desynchronosis was associated with leukocytosis, lymphoand monocytopenia, activation of oxygen-dependent metabolism of blood phagocytes, suppression of Th1-and Th2-dependent immune response. Desynchronosis was also accompanied by decreased concentrations of serum melatonin, IFNγ and IL-4, along with increased cortisol concentrations. Reduced IFNγ and IL-4 amounts was associated with decreased melatonin concentrations

  11. RESULTS OF CALCULATION-EXPERIMENTAL INVESTIGATIONS OF ELECTRO-THERMAL RESISTIBILITY OF SHEET STEEL SAMPLES TO ACTION OF RATIONED COMPONENTS OF PULSED CURRENT OF ARTIFICIAL LIGHTING

    Directory of Open Access Journals (Sweden)

    M.I. Baranov

    2016-06-01

    Full Text Available Purpose. Calculation and experimental researches of the electro-thermal resistibility of the steel sheet samples to action standard pulse current components of the artificial lightning with amplitude-time parameters (ATP, corresponded the requirements of normative documents of USA for SAE ARP 5412 & SAE ARP 5416. Methodology. Electrophysics bases of technique of high tensions and large impulsive currents (LIC, and also scientific and technical bases of planning of devices of high-voltage impulsive technique and measuring in them LIC. Сurrent amplitude ImA=±200 kA (with a tolerance of ±10 %; current action integral JA=2∙106 A2•s (with a tolerance of ±20 %; time, corresponding to the amplitude of the current ImA, tmA≤50 microseconds; the duration of the current flow τpA≤500 microseconds. Results. The results of the evaluation of the calculated and experimental studies of electro-thermal resistance of the samples of plates measuring 0,5 m  0,5 m stainless steel 1 mm thickness to the action on them artificial lightning impulse currents with rationed ATP on the requirements of normative documents of USA for SAE ARP 5412 & SAE ARP 5416. A pulse A- component have a first amplitude 192 kA, the corresponding time of 34 μs, and the duration aperiodic component amplitude 804 A, corresponding to the time 9 ms. It has been shown that the long C- component current of artificial lightning can lead to keyhole these samples. The diameter of the holes in this thin steel sheet, which is formed during the flow of current C- components can reach 15 mm. The results of calculation and experiment agree within 28 %. Originality. For the first time in world practice on the generator large pulsed currents experimental studies of resistibility of sheet steel samples to the action of artificial lightning currents with critical parameters. Practical value. Using the results obtained in the practice of lightning protection will significantly improve the

  12. Current methods of the modeling of experimental diabetes mellitus type 2: a literature review

    Directory of Open Access Journals (Sweden)

    Yu. M. Kolesnyk

    2016-01-01

    Full Text Available Background. Diabetes mellitus (DM became a major problem of the healthcare in Ukraine. The rapid increase in the incidence was noticed especially in recent decade. The treatment of diabetes and its complications become a difficult task. From this standpoint the experimental modeling of diabetes is rather essential. Using the experimental models gives the possibility to assess the significance of the activity of pharmacological substances or to find out new mechanism in the action of medicaments. The aim of this review is to light up the most studied and common experimental models of diabetes mellitus type 2 (T2DM in small rodents and find out their drawbacks. It is known the background of T2DM is the violation of the insulin homeostasis such as the resistance of peripheral tissues to insulin as well as the dysfunction of the pancreatic beta-cells, which both lead to appearance of such phenomena as the glucosetoxicity and the lipotoxicity. In the end they both could result in life threatening vascular complications. Considering the steady growth of T2DM patients, the development both of the drug and non-drug methods of its treatment with the high therapeutically efficiency and the perfect safety profile becomes essential. The most important stage of the search of new ways of influence on pathogenetic links of T2DM is the preclinical stage. From this standpoint the usage of experimental models of T2DM has a huge importance. There are a lot of models of T2DM developed by different scientists. These models could be spontaneous or be induced by different chemical diabetogenic substances, diet or surgical interventions or be a combination of methods listed above. Conclusions. We should underline the adequate modeling of DM2T is the necessary basis for the pre-clinical study of drug-based and not-drug methods of correction of the hyperglycemic states. Using different models makes it possible for infer the obtained experimental results to the society

  13. Experimental results of current distribution in Rutherford-type LHC cables

    CERN Document Server

    Verweij, A P

    2000-01-01

    Current distribution among the wires of multi-strand superconducting cables is an important item for accelerator magnets. A non-uniform distribution could cause additional field distortions in the magnet bore and can as well be one of the reasons of premature quenching. Since two years electrical measurements on superconducting Rutherford-type cables are performed at CERN as part of the reception tests for the Large Hadron Collider (LHC). Cable samples of 2.4 m length are tested at currents up to 32 kA, temperatures around 1.9 and 4.3 K, and fields up to 10 T, applied perpendicularly as well as parallel to the broad face of the cable. Last year, an array of 24 Hall probes was installed in the test set-up in order to measure the self-field of the cable samples along one cable pitch. Each of the probes measures the local field generated by the current in the strands close by, and the results of the all probes reflect therefore the distribution of the strand currents. Experiments are done varying the applied fie...

  14. Resonance Chiral Lagrangian Currents and Experimental Data for $\\tau^-\\to\\pi^{-}\\pi^{-}\\pi^{+}\

    CERN Document Server

    Nugent, I M; Roig, P; Shekhovtsova, O; Was, Z

    2013-01-01

    In this paper we document the modifications introduced to the previous version of the Resonance Chiral Lagrangian current ({\\it Phys.Rev.} {\\bf D86} (2012) 113008) of the $\\tau^\\pm \\to \\pi^\\pm \\pi^\\pm \\pi^\\mp \

  15. Experimental Study on the Influence of AC Stray Current on the Cathodic Protection of Buried Pipe

    Directory of Open Access Journals (Sweden)

    Qingmiao Ding

    2016-01-01

    Full Text Available The size of the damaged area of the coating and its position on the pipeline impacted the cathodic protection potential, and there was a damaged area of the greatest impact value. When damaged area was 300 mm2, the IR drop was the largest, and this situation could easily lead to inadequate protection; when the parallel spacing between pipeline and interference source was unchanged, the measured value curves of cathodic protection potential presented “U” shaped trend with the increasing stray current interference intensity. Under certain parallel spacing between pipeline and interference source, high alternating stray current intensity would cause serious negative offsets, so that the overprotection of the pipeline occurred, and make the coating crack; there was a parallel threshold length. When less than the threshold, the pipe-ground potential increases rapidly with the parallel length increasing. In order to judge whether a pipeline was interference by AC stray current and the risk of stray current corrosion, we should make a comprehensive analysis of the cathodic protection energizing potential, the switch-off potential, AC pipe-soil potential, IR drops, and so on.

  16. Experimental determination of the electrical resistivity of iron at Earth’s core conditions

    Science.gov (United States)

    Ohta, Kenji; Kuwayama, Yasuhiro; Hirose, Kei; Shimizu, Katsuya; Ohishi, Yasuo

    2016-06-01

    Earth continuously generates a dipole magnetic field in its convecting liquid outer core by a self-sustained dynamo action. Metallic iron is a dominant component of the outer core, so its electrical and thermal conductivity controls the dynamics and thermal evolution of Earth’s core. However, in spite of extensive research, the transport properties of iron under core conditions are still controversial. Since free electrons are a primary carrier of both electric current and heat, the electron scattering mechanism in iron under high pressure and temperature holds the key to understanding the transport properties of planetary cores. Here we measure the electrical resistivity (the reciprocal of electrical conductivity) of iron at the high temperatures (up to 4,500 kelvin) and pressures (megabars) of Earth’s core in a laser-heated diamond-anvil cell. The value measured for the resistivity of iron is even lower than the value extrapolated from high-pressure, low-temperature data using the Bloch-Grüneisen law, which considers only the electron-phonon scattering. This shows that the iron resistivity is strongly suppressed by the resistivity saturation effect at high temperatures. The low electrical resistivity of iron indicates the high thermal conductivity of Earth’s core, suggesting rapid core cooling and a young inner core less than 0.7 billion years old. Therefore, an abrupt increase in palaeomagnetic field intensity around 1.3 billion years ago may not be related to the birth of the inner core.

  17. Current and hydrographic conditions at the East Flower Garden Bank in 2011

    Science.gov (United States)

    Teague, W. J.; Wijesekera, H. W.; Jarosz, E.; Fribance, D. B.; Lugo-Fernández, A.; Hallock, Z. R.

    2013-07-01

    The East Flower Garden Bank (EFGB), part of the Flower Garden Banks National Marine Sanctuary, is located in the northwestern Gulf of Mexico, about 185 km southeast of Galveston, Texas. With a width of about 5 km, the steep-sided bank rises from water depths of over 100 m to within less than 20 m of the surface. Four acoustic Doppler current profiler (ADCP) moorings and four temperature/salinity strings were deployed around the EFGB with an additional ADCP on top of the bank for about 1 year. The main objective was to understand the ocean processes over the EFGB and to examine the importance of the topographically induced processes on shelf edge circulation on longer (e.g. days to seasonal) time scales. Currents were generally eastward over the bank in the upper water column. Eddy events occasionally reversed the eastward flow for a few days. Currents in the lower water column tended to align with the bank's bathymetry and mostly were directed offshore at the southern edge of the bank. Wind and eddy events moved both shelf and off-shelf waters over the bank, including waters from as deep as 200 m through upwelling and/or mixing processes. Mixed layers changed by as much as 50 m in a couple of days. Inertial currents occurred throughout the year and were often much larger than the tidal currents. Commonly, the inertial currents were strong enough to reverse the predominantly eastward current flow on time scales of less than a day. Westward propagating cyclonic eddies (often associated with anticyclonic eddies) likely connect biological activities of the EFGB with the West Flower Garden Bank. Banks such as the EFGB, with large aspect ratios and heights, strongly alter circulation and enhance exchange processes at the shelf break.

  18. Electrodynamic stabilization conditions for high-temperature superconducting composites with different types of current-voltage characteristic nonlinearity

    Science.gov (United States)

    Arkharov, A. M.; Lavrov, N. A.; Romanovskii, V. R.

    2014-06-01

    The current instability is studied in high-temperature superconducting current-carrying elements with I- V characteristics described by power or exponential equations. Stability analysis of the macroscopic states is carried out in terms of a stationary zero-dimensional model. In linear temperature approximation criteria are derived that allow one to find the maximum allowable values of the induced current, induced electric field intensity, and overheating of the superconductor. A condition is formulated for the complete thermal stabilization of the superconducting composite with regard to the nonlinearity of its I- V characteristic. It is shown that both subcritical and supercritical stable states may arise. In the latter case, the current and electric field intensity are higher than the preset critical parameters of the superconductor. Conditions for these states depending on the properties of the matrix, superconductor's critical current, fill factor, and nonlinearity of the I- V characteristic are discussed. The obtained results considerably augment the class of allowable states for high-temperature superconductors: it is demonstrated that there exist stable resistive conditions from which superconductors cannot pass to the normal state even if the parameters of these conditions are supercritical.

  19. Collecting conditions usage metadata to optimize current and future ATLAS software and processing

    CERN Document Server

    Barberis, Dario; The ATLAS collaboration; Gallas, Elizabeth; Oda, Susumu

    2016-01-01

    Conditions data (for example: alignment, calibration, data quality) are used extensively in the processing of real and simulated data in ATLAS. The volume and variety of the conditions data needed by different types of processing are quite diverse, so optimizing its access requires a careful understanding of conditions usage patterns. These patterns can be quantified by mining representative log files from each type of processing and gathering detailed information about conditions usage for that type of processing into a central repository. In this presentation, we describe the systems developed to collect this conditions usage metadata per job type and describe a few specific (but very different) ways in which it has been used. For example, it can be used to cull specific conditions data into a much more compact package to be used by jobs doing similar types of processing: these customized collections can then be shipped with jobs to be executed on isolated worker nodes (such as HPC farms) that have no netwo...

  20. Investigation of Rayleigh-Taylor turbulence and mixing using direct numerical simulation with experimentally-measured initial conditions. I. Comparison to experimental data

    Energy Technology Data Exchange (ETDEWEB)

    Mueschke, N; Schilling, O

    2008-07-23

    A 1152 x 760 x 1280 direct numerical simulation (DNS) using initial conditions, geometry, and physical parameters chosen to approximate those of a transitional, small Atwood number Rayleigh-Taylor mixing experiment [Mueschke, Andrews and Schilling, J. Fluid Mech. 567, 27 (2006)] is presented. The density and velocity fluctuations measured just off of the splitter plate in this buoyantly unstable water channel experiment were parameterized to provide physically-realistic, anisotropic initial conditions for the DNS. The methodology for parameterizing the measured data and numerically implementing the resulting perturbation spectra in the simulation is discussed in detail. The DNS model of the experiment is then validated by comparing quantities from the simulation to experimental measurements. In particular, large-scale quantities (such as the bubble front penetration hb and the mixing layer growth parameter {alpha}{sub b}), higher-order statistics (such as velocity variances and the molecular mixing parameter {theta}), and vertical velocity and density variance spectra from the DNS are shown to be in favorable agreement with the experimental data. Differences between the quantities obtained from the DNS and from experimental measurements are related to limitations in the dynamic range of scales resolved in the simulation and other idealizations of the simulation model. This work demonstrates that a parameterization of experimentally-measured initial conditions can yield simulation data that quantitatively agrees well with experimentally-measured low- and higher-order statistics in a Rayleigh-Taylor mixing layer. This study also provides resolution and initial conditions implementation requirements needed to simulate a physical Rayleigh-Taylor mixing experiment. In Part II [Mueschke and Schilling, Phys. Fluids (2008)], other quantities not measured in the experiment are obtained from the DNS and discussed, such as the integral- and Taylor-scale Reynolds numbers

  1. Repeated examination of natural sapovirus infections in pig litters raised under experimental conditions.

    Science.gov (United States)

    Lauritsen, Klara Tølbøll; Hansen, Mette Sif; Johnsen, Christina K; Jungersen, Gregers; Böttiger, Blenda

    2015-09-26

    Porcine sapovirus, belonging to the family Caliciviridae, is an enteric virus that is widespread in the swine industry worldwide. A total of 14 sapovirus genogroups have been suggested and the most commonly found genogroup in swine is genogroup III (GIII). The goal of the present experiment was to examine the presence of sapovirus in 51 naturally infected pigs at two different time points. The pigs were kept under experimental conditions after weaning. Previous studies on sapovirus have primarily been of a cross sectional nature, typically prevalence studies performed on farms and abattoirs. In the present study, faecal samples, collected from each pig at 5½ weeks and 15-18 weeks of age, were analysed for sapovirus by reverse transciptase polymerase chain reaction and positive findings were genotyped by sequencing. At 5½ weeks of age, sapovirus was detected in the majority of the pigs. Sequencing revealed four different strains in the 5½ week olds-belonging to genogroups GIII and GVII. Ten to 13 weeks later, the virus was no longer detectable from stools of infected pigs. However, at this time point 13 pigs were infected with another GIII sapovirus strain not previously detected in the pigs studied. This GIII strain was only found in pigs that, in the initial samples, were virus-negative or positive for GVII. At 5 weeks of age 74 % of the pigs were infected with sapovirus. At 15-18 weeks of age all pigs had cleared their initial infection, but a new sapovirus GIII strain was detected in 25 % of the pigs. None of the pigs initially infected with the first GIII strain were reinfected with this new GIII strain, which may indicate the presence of a genogroup-specific immunity.

  2. Aerosol transmission of foot-and-mouth disease virus Asia-1 under experimental conditions.

    Science.gov (United States)

    Colenutt, C; Gonzales, J L; Paton, D J; Gloster, J; Nelson, N; Sanders, C

    2016-06-30

    Foot-and-mouth disease virus (FMDV) control measures rely on understanding of virus transmission mechanisms. Direct contact between naïve and infected animals or spread by contaminated fomites is prevented by quarantines and rigorous decontamination procedures during outbreaks. Transmission of FMDV by aerosol may not be prevented by these control measures and this route of transmission may allow infection of animals at distance from the infection source. Understanding the potential for aerosol spread of specific FMDV strains is important for informing control strategies in an outbreak. Here, the potential for transmission of an FMDV Asia 1 strain between pigs and cattle by indirect aerosol exposure was evaluated in an experimental setting. Four naïve calves were exposed to aerosols emitted from three infected pigs in an adjacent room for a 10h period. Direct contact between pigs and cattle and fomite transfer between rooms was prevented. Viral titres in aerosols emitted by the infected pigs were measured to estimate the dose that calves were exposed to. One of the calves developed clinical signs of FMD, whilst there was serological evidence for spread to cattle by aerosol transmission in the remaining three calves. This highlights the possibility that this FMDV Asia 1 strain could be spread by aerosol transmission given appropriate environmental conditions should an outbreak occur in pigs. Our estimates suggest the exposure dose required for aerosol transmission was higher than has been previously quantified for other serotypes, implying that aerosols are less likely to play a significant role in transmission and spread of this FMDV strain.

  3. Thermoelectric Property Dependence on Performance of Peltier Current Leads Under Overcurrent Conditions

    Science.gov (United States)

    Kawahara, Toshio; Emoto, Masahiko; Hamabe, Makoto; Watanabe, Hirofumi; Ivanov, Yury; Sun, Jian; Yamaguchi, Satarou

    2012-06-01

    Superconductivity can potentially provide a solution to the world's energy needs because superconducting transmission and distribution (T&D) systems can decrease losses and are also capable of integrating renewables into the power grid. At Chubu University we have built a 200-m-class superconducting direct-current T&D system (CASER-2). To minimize heat leakage from the current leads, we investigated thermoelectric materials. The Peltier current lead (PCL) is one of the key technologies that will enhance the performance of superconducting systems: as direct current (DC) flows through the current lead, thermoelectric elements on opposite terminations of the superconducting line can be used to decrease the heat ingress to the cryogenic environment ( n-type on one end, p-type on the opposite end). The heat leakage to the cryogenic environment depends on the properties of the thermoelectric materials. In this paper, we estimate the performance of PCLs in cryogenic operations, including the potential for overcurrent operation, through both modeling and experiments at CASER-2.

  4. The excitation conditions of magnetospheric convection by the electric current generated in the bow shock

    Science.gov (United States)

    Sedykh, P. A.; Ponomarev, E. A.

    The solar wind undergoes the greatest change of its parameters during the passage through the bow shock front Its density in this case increases by the factor of four and gas and magnetic pressure increase more than by an order of magnitude In this paper we re-examine the consequences of the fact of electric current generation at the bow shock front that we considered at an earlier date and the dependence of the direction of this current on the sign of IMF Bz-component The first consequence is the closure of the aforementioned current through the magnetosphere It was found that this process is a two-stage one Initially the electric field penetrates and establishes in the medium a new convective regime After that depending on the degree of flow inhomogeneity a plasma density distribution can be established which corresponds to the electric current equal to the external current The new steady state to which the new convection velocity field and the new plasma pressure field correspond is established within the time of the order of the transit time taken by the magnetosonic wave to propagate through the entire system Also a linkage between the power dissipated inside the magnetosphere and the parameters of plasma convection existing therein is shown

  5. Melt-Flow Behaviours of Thermoplastic Materials under Fire Conditions: Recent Experimental Studies and Some Theoretical Approaches

    Directory of Open Access Journals (Sweden)

    Paul Joseph

    2015-12-01

    Full Text Available Polymeric materials often exhibit complex combustion behaviours encompassing several stages and involving solid phase, gas phase and interphase. A wide range of qualitative, semi-quantitative and quantitative testing techniques are currently available, both at the laboratory scale and for commercial purposes, for evaluating the decomposition and combustion behaviours of polymeric materials. They include, but are not limited to, techniques such as: thermo-gravimetric analysis (TGA, oxygen bomb calorimetry, limiting oxygen index measurements (LOI, Underwriters Laboratory 94 (UL-94 tests, cone calorimetry, etc. However, none of the above mentioned techniques are capable of quantitatively deciphering the underpinning physiochemical processes leading to the melt flow behaviour of thermoplastics. Melt-flow of polymeric materials can constitute a serious secondary hazard in fire scenarios, for example, if they are present as component parts of a ceiling in an enclosure. In recent years, more quantitative attempts to measure the mass loss and melt-drip behaviour of some commercially important chain- and step-growth polymers have been accomplished. The present article focuses, primarily, on the experimental and some theoretical aspects of melt-flow behaviours of thermoplastics under heat/fire conditions.

  6. Protobacco Media Exposure and Youth Susceptibility to Smoking Cigarettes, Cigarette Experimentation, and Current Tobacco Use among US Youth.

    Directory of Open Access Journals (Sweden)

    Erika B Fulmer

    Full Text Available Youth are exposed to many types of protobacco influences, including smoking in movies, which has been shown to cause initiation. This study investigates associations between different channels of protobacco media and susceptibility to smoking cigarettes, cigarette experimentation, and current tobacco use among US middle and high school students.By using data from the 2012 National Youth Tobacco Survey, structural equation modeling was performed in 2013. The analyses examined exposure to tobacco use in different channels of protobacco media on smoking susceptibility, experimentation, and current tobacco use, accounting for perceived peer tobacco use.In 2012, 27.9% of respondents were never-smokers who reported being susceptible to trying cigarette smoking. Cigarette experimentation increased from 6.3% in 6th grade to 37.1% in 12th grade. Likewise, current tobacco use increased from 5.2% in 6th grade to 33.2% in 12th grade. Structural equation modeling supported a model in which current tobacco use is associated with exposure to static advertising through perception of peer use, and by exposure to tobacco use depicted on TV and in movies, both directly and through perception of peer use. Exposure to static advertising appears to directly increase smoking susceptibility but indirectly (through increased perceptions of peer use to increase cigarette experimentation. Models that explicitly incorporate peer use as a mediator can better discern the direct and indirect effects of exposure to static advertising on youth tobacco use initiation.These findings underscore the importance of reducing youth exposure to smoking in TV, movies, and static advertising.

  7. Erosion Control of Scour during Construction; Report 3. Experimental Measurements of Refraction, Diffraction, and Current Patterns Near Jetties.

    Science.gov (United States)

    1980-09-01

    predict the probable magnitude of (Continued) DD vi’Ra 03 1wom or INov OM @ISDETR Unclassified S.CUm TY CLAS-.lCATIO OF THIS PAS.. (..m 0. Yw...transport of the bottom material at the particular site. The purpose of this study was to obtain detailed and precise experimental data regarding wave...currents. This removal of material from around structures is often not compensated by an influx of additional material ; the result is scour, or

  8. Experimental investigations of electric current under transverse and longitudinal electric field in uniaxially deformed p-Ge

    Science.gov (United States)

    Abramov, A. A.; Akimov, V. I.; Dalakyan, A. T.; Tulupenko, Victor N.; Zaitsev, A. M.; Danilov, S. N.; Firsov, D. A.; Shalygin, V. A.

    1999-11-01

    Comparison between cases of longitudinal and transverse directions of uniaxial pressure and strong electric field, affected the bulk hole germanium, to use it for lasting in far IR region has been carried out. Conclusion about preference of crossed directions is made. Threshold pressure, at which stimulated radiation arises, independence of crystallographic direction, along which external influences are applied, is also discussed. The results of experimental investigations of the crossed directions of uniaxial pressure and electric current are given.

  9. Numerical simulation and experimental study of the hydrodynamics of a modeled reef located within a current

    Institute of Scientific and Technical Information of China (English)

    姜昭阳; 梁振林; 唐衍力; 黄六一; 于定勇; 姜曼松

    2010-01-01

    The hydrodynamic forces and flow field of artificial reef models in steady flow were numerically investigated using the RNG k–εturbulent model.The numerical simulation results are consistent with results observed by experimental means.A comparative study indicates that the corresponding errors of forces between calculated values and values observed in the experiment vary in the range of 2.3%–11.2%and that the corresponding errors of velocities vary in the range of 1.3%–15.8%. The flow field numerical result...

  10. Survey of Current Experimental Studies of Effects of Traditional Chinese Medicine on Peripheral Nerve Regeneration

    Institute of Scientific and Technical Information of China (English)

    WU Qun-li; LIANG Xiao-chun

    2006-01-01

    The repairing and regeneration of peripheral nerves is a very complex biological and cytological process, its mechanism is unclear so far, and thus results in the lack of specific and effectual therapy and medicament. Chinese herbs and their effective components have their own inimitable predominance in promoting peripheral nerve regeneration, such as their multi-factorial, multi-target and multi-functional action, abundant source, inexpensive, etc. In this paper, the experimental studies reported in recent 5 years concerning the effects of Chinese herbs or their active components on peripheral nerve repairing and regeneration are reviewed in respects of the integral level, cellular level, molecular level and gene level.

  11. Experimental Verification of Overlimiting Current by Surface Conduction and Electro-osmotic Flow in Microchannels

    CERN Document Server

    Nam, Sungmin; Heo, Joonseong; Lim, Geunbae; Bazant, Martin Z; Sung, Gunyong; Kim, Sung Jae

    2014-01-01

    Possible mechanisms of overlimiting current in unsupported electrolytes, exceeding diffusion limitation, have been intensely studied for their fundamental significance and applications to desalination, separations, sensing, and energy storage. In bulk membrane systems, the primary physical mechanism is electro-convection, driven by electro-osmotic instability on the membrane surface. It has recently been predicted that confinement by charged surfaces in microchannels or porous media favors two new mechanisms, electro-osmotic flow (EOF) and surface conduction (SC), driven by large electric fields in the depleted region acting on the electric double layers on the sidewalls. Here, we provide the first direct evidence for the transition from SC to EOF above a critical channel height, using in situ particle tracking and current-voltage measurements in a micro/nanofluidic device. The dependence of the over-limiting conductance on channel depth (d) is consistent with theoretical predictions, scaling as d^-1 for SC a...

  12. Foreign Languages in Vienna Primary Schools – in Mainstream Education and in Current Experimental Models

    Directory of Open Access Journals (Sweden)

    Renate Seebauer

    2015-05-01

    Full Text Available Starting with a short retrospective and an overview of the incorporation of foreign language learning into the Austrian curriculum for primary schools the paper in hand describes the current situation of foreign language teaching in primary schools as well as various current models of foreign language education in primary schools in Vienna (school year 1 to 4. In terms of objectives these models exceed the requirements of the curriculum of the formal education system or regard themselves as quantitative and qualitative enrichment. They follow different didactic approaches and/or site-specific characteristics and needs. The formulation of basic skills is to be understood as an attempt to find a common basis of output indicators and to facilitate the transition to secondary education. Although English is the most commonly chosen resp. offered language the paper also refers to school experiments that focus on Romance or Slavic languages or on languages of Austra’s neighbouring countries.

  13. Decoupled Double Synchronous Reference Frame Current Controller for Unbalanced Grid Voltage Conditions

    DEFF Research Database (Denmark)

    Reyes, M.; Rodriguez, Pedro; Vazquez, S.

    2012-01-01

    Due to the growing changes in the electrical network related to the new distributed generation scheme and the integration of renewable energy sources, new requirements for grid-connected power converters are being defined in the new grid codes. The injection of positive- and negative......-sequence current components is becoming necessary for achieving new capabilities like the reactive power injection during a grid fault. This paper deals with a fundamental issue in this topic, i.e., the performance of the current controller. Classical dq controllers, which are extensively used in industrial...

  14. Experimental investigation of quasiperiodic-chaotic-quasiperiodic-chaotic transition in a direct current magnetron sputtering plasma

    Energy Technology Data Exchange (ETDEWEB)

    Sabavath, Gopi Kishan; Banerjee, I.; Mahapatra, S. K., E-mail: skmahapatra@bitmesra.ac.in [Plasma Laboratory, Department of Physics, Birla Institute of Technology-Mesra, Ranchi 835215 (India); Shaw, Pankaj Kumar; Sekar Iyengar, A. N. [Plasma Physics Division, Saha Institute of Nuclear Physics, 1/AF, Bidhannagar, Kolkata 700064 (India)

    2015-08-15

    Floating potential fluctuations from a direct current magnetron sputtering plasma have been analysed using time series analysis techniques like phase space plots, power spectra, frequency bifurcation plot, etc. The system exhibits quasiperiodic-chaotic-quasiperiodic-chaotic transitions as the discharge voltage was increased. The transitions of the fluctuations, quantified using the largest Lyapunov exponent, have been corroborated by Hurst exponent and the Shannon entropy. The Shannon entropy is high for quasiperiodic and low for chaotic oscillations.

  15. Experimental studies on benzene carcinogenicity at the Bologna Institute of Oncology: current results and ongoing research.

    Science.gov (United States)

    Maltoni, C; Conti, B; Cotti, G; Belpoggi, F

    1985-01-01

    In 1977 Maltoni and Scarnato were the first to demonstrate that benzene is an experimental carcinogen in rats. With that and other experiments, Maltoni et al have shown that benzene administered by ingestion (stomach tube) or inhalation is a multipotential carcinogen in rats (of two different strains) and mice and produces a variety of tumors, namely: Zymbal gland carcinomas, oral and nasal cavity carcinomas, skin carcinomas, acanthomas, dysplasias and carcinomas of forestomach, mammary malignant tumors, hepatomas, liver angiosarcomas, hemolymphoreticular neoplasias, and pulmonary tumors. The incidence of Zymbal gland carcinomas and carcinomas of the oral and nasal cavities is affected by the length of treatment by inhalation and by the age of animals. However, the available epidemiological and experimental data at present do not provide precise information on the risk of doses around or below 10 ppm. Long-term carcinogenicity bioassays at 50, 25, 10, 5 and 1 ppm may be helpful for scientific risk assessment. In addition, these experiments have shown that toluene, xylene, and ethylbenzene, at high concentrations, cause an increase in the number of total malignant tumors.

  16. Single-Case Experimental Designs: A Systematic Review of Published Research and Current Standards

    Science.gov (United States)

    Smith, Justin D.

    2013-01-01

    This article systematically reviews the research design and methodological characteristics of single-case experimental design (SCED) research published in peer-reviewed journals between 2000 and 2010. SCEDs provide researchers with a flexible and viable alternative to group designs with large sample sizes. However, methodological challenges have precluded widespread implementation and acceptance of the SCED as a viable complementary methodology to the predominant group design. This article includes a description of the research design, measurement, and analysis domains distinctive to the SCED; a discussion of the results within the framework of contemporary standards and guidelines in the field; and a presentation of updated benchmarks for key characteristics (e.g., baseline sampling, method of analysis), and overall, it provides researchers and reviewers with a resource for conducting and evaluating SCED research. The results of the systematic review of 409 studies suggest that recently published SCED research is largely in accordance with contemporary criteria for experimental quality. Analytic method emerged as an area of discord. Comparison of the findings of this review with historical estimates of the use of statistical analysis indicates an upward trend, but visual analysis remains the most common analytic method and also garners the most support amongst those entities providing SCED standards. Although consensus exists along key dimensions of single-case research design and researchers appear to be practicing within these parameters, there remains a need for further evaluation of assessment and sampling techniques and data analytic methods. PMID:22845874

  17. Glazed clay pottery and lead exposure in Mexico: Current experimental evidence.

    Science.gov (United States)

    Diaz-Ruiz, Araceli; Tristán-López, Luis Antonio; Medrano-Gómez, Karen Itzel; Torres-Domínguez, Juan Alejandro; Ríos, Camilo; Montes, Sergio

    2017-11-01

    Lead exposure remains a significant environmental problem; lead is neurotoxic, especially in developing humans. In Mexico, lead in human blood is still a concern. Historically, much of the lead exposure is attributed to the use of handcrafted clay pottery for cooking, storing and serving food. However, experimental cause-and-effect demonstration is lacking. The present study explores this issue with a prospective experimental approach. We used handcrafted clay containers to prepare and store lemonade, which was supplied as drinking water to pregnant rats throughout the gestational period. We found that clay pots, jars, and mugs leached on average 200 µg/l lead, and exposure to the lemonade resulted in 2.5 µg/dl of lead in the pregnant rats' blood. Neonates also showed increased lead content in the hippocampus and cerebellum. Caspase-3 activity was found to be statistically increased in the hippocampus in prenatally exposed neonates, suggesting increased apoptosis in that brain region. Glazed ceramics are still an important source of lead exposure in Mexico, and our results confirm that pregnancy is a vulnerable period for brain development.

  18. Protein folding: Defining a standard set of experimental conditions and a preliminary kinetic data set of two-state proteins

    DEFF Research Database (Denmark)

    Maxwell, Karen L.; Wildes, D.; Zarrine-Afsar, A.;

    2005-01-01

    constructs. The lack of a single approach to data analysis and error estimation, or even of a common set of units and reporting standards, further hinders comparative studies of folding. In an effort to overcome these problems, we define here a consensus set of experimental conditions (25°C at pH 7.0, 50 m...... rates, thermodynamics, and structure across diverse sets of proteins. These difficulties include the wide, potentially confounding range of experimental conditions and methods employed to date and the difficulty of obtaining correct and complete sequence and structural details for the characterized......M buffer), data analysis methods, and data reporting standards that we hope will provide a benchmark for experimental studies. We take the first step in this initiative by describing the folding kinetics of 30 apparently two-state proteins or protein domains under the consensus conditions. The goal of our...

  19. Food safety and ecologization: practical solutions to problems at the regional level in current economic conditions

    Directory of Open Access Journals (Sweden)

    Lysochenko Alla, A.

    2015-03-01

    Full Text Available Ensuring food security and greening both at the level of the country, and at the level of regions are main objectives of modern agroeconomic policy. The state support creates favorable conditions for dynamic development of agrarian and industrial complex, raises investment opportunities and competitiveness of agricultural producers. A realization of the actions directed on assistance to the enterprises making import-substituting production of the regional agro-industrial complex is actual in modern economic conditions. The solution of this problem consists of investment projects implementation and production expansion of the operating enterprises. Considering new economic conditions, the ensuring financial stability of agricultural producers, availability of the food to needy segments of the population, production of valeologically safe food, and also increase efficiency of use of natural resources and conditions along with preservation of quality of environment at the local, regional and global levels are particularly acute challenges. State regulation of development of an agrofood complex of Russia remains a necessary condition for its reproduction functioning, and the social and economic policy has to provide economic availability of the food to all groups of the population that causes need of standard and legal fixing of mechanisms offood security achievement at the regional level.

  20. Current and experimental treatments of Parkinson disease: A guide for neuroscientists.

    Science.gov (United States)

    Oertel, Wolfgang; Schulz, Jörg B

    2016-10-01

    Over a period of more than 50 years, the symptomatic treatment of the motor symptoms of Parkinson disease (PD) has been optimized using pharmacotherapy, deep brain stimulation, and physiotherapy. The arsenal of pharmacotherapies includes L-Dopa, several dopamine agonists, inhibitors of monoamine oxidase (MAO)-B and catechol-o-methyltransferase (COMT), and amantadine. In the later course of the disease, motor complications occur, at which stage different oral formulations of L-Dopa or dopamine agonists with long half-life, a transdermal application or parenteral pumps for continuous drug supply can be subscribed. Alternatively, the patient is offered deep brain stimulation of the subthalamic nucleus (STN) or the internal part of the globus pallidus (GPi). For a more efficacious treatment of motor complications, new formulations of L-Dopa, dopamine agonists, and amantadine as well as new MAO-B and COMT inhibitors are currently tested in clinical trials, and some of them already yielding positive results in phase 3 trials. In addition, non-dopaminergic agents have been tested in the early clinical phase for the treatment of motor fluctuations and dyskinesia, including adenosine A2A antagonists (istradefylline, preladenant, and tozadenant) and modulators of the metabolic glutamate receptor 5 (mGluR5 - mavoglurant) and serotonin (eltoprazine) receptors. Recent clinical trials testing coenzyme Q10, the dopamine agonist pramipexole, creatine monohydrate, pioglitazone, or AAV-mediated gene therapy aimed at increasing expression of neurturin, did not prove efficacious. Treatment with nicotine, caffeine, inosine (a precursor of urate), and isradipine (a dihydropyridine calcium channel blocker), as well as active and passive immunization against α-synuclein and inhibitors or modulators of α-synuclein-aggregation are currently studied in clinical trials. However, to date, no disease-modifying treatment is available. We here review the current status of treatment options for

  1. Benchmarking of codes for electron cyclotron heating and electron cyclotron current drive under ITER conditions

    NARCIS (Netherlands)

    Prater, R.; Farina, D.; Gribov, Y.; Harvey, R. W.; Ram, A. K.; Lin-Liu, Y. R.; Poli, E.; Smirnov, A. P.; Volpe, F.; Westerhof, E.; Zvonkovo, A.

    2008-01-01

    Optimal design and use of electron cyclotron heating requires that accurate and relatively quick computer codes be available for prediction of wave coupling, propagation, damping and current drive at realistic levels of EC power. To this end, a number of codes have been developed in laboratories wor

  2. Development of an Experimental Data Base to Validate Compressor-Face Boundary Conditions Used in Unsteady Inlet Flow Computations

    Science.gov (United States)

    Sajben, Miklos; Freund, Donald D.

    1998-01-01

    The ability to predict the dynamics of integrated inlet/compressor systems is an important part of designing high-speed propulsion systems. The boundaries of the performance envelope are often defined by undesirable transient phenomena in the inlet (unstart, buzz, etc.) in response to disturbances originated either in the engine or in the atmosphere. Stability margins used to compensate for the inability to accurately predict such processes lead to weight and performance penalties, which translate into a reduction in vehicle range. The prediction of transients in an inlet/compressor system requires either the coupling of two complex, unsteady codes (one for the inlet and one for the engine) or else a reliable characterization of the inlet/compressor interface, by specifying a boundary condition. In the context of engineering development programs, only the second option is viable economically. Computations of unsteady inlet flows invariably rely on simple compressor-face boundary conditions (CFBC's). Currently, customary conditions include choked flow, constant static pressure, constant axial velocity, constant Mach number or constant mass flow per unit area. These conditions are straightforward extensions of practices that are valid for and work well with steady inlet flows. Unfortunately, it is not at all likely that any flow property would stay constant during a complex system transient. At the start of this effort, no experimental observation existed that could be used to formulate of verify any of the CFBC'S. This lack of hard information represented a risk for a development program that has been recognized to be unacceptably large. The goal of the present effort was to generate such data. Disturbances reaching the compressor face in flight may have complex spatial structures and temporal histories. Small amplitude disturbances may be decomposed into acoustic, vorticity and entropy contributions that are uncoupled if the undisturbed flow is uniform. This study

  3. Conceptual design of a thermalhydraulic loop for multiple test geometries at supercritical conditions named Supercritical Phenomena Experimental Test Apparatus (SPETA)

    Science.gov (United States)

    Adenariwo, Adepoju

    The efficiency of nuclear reactors can be improved by increasing the operating pressure of current nuclear reactors. Current CANDU-type nuclear reactors use heavy water as coolant at an outlet pressure of up to 11.5 MPa. Conceptual SuperCritical Water Reactors (SCWRs) will operate at a higher coolant outlet pressure of 25 MPa. Supercritical water technology has been used in advanced coal plants and its application proves promising to be employed in nuclear reactors. To better understand how supercritical water technology can be applied in nuclear power plants, supercritical water loops are used to study the heat transfer phenomena as it applies to CANDU-type reactors. A conceptual design of a loop known as the Supercritical Phenomena Experimental Apparatus (SPETA) has been done. This loop has been designed to fit in a 9 m by 2 m by 2.8 m enclosure that will be installed at the University of Ontario Institute of Technology Energy Research Laboratory. The loop include components to safely start up and shut down various test sections, produce a heat source to the test section, and to remove reject heat. It is expected that loop will be able to investigate the behaviour of supercritical water in various geometries including bare tubes, annulus tubes, and multi-element-type bundles. The experimental geometries are designed to match the fluid properties of Canadian SCWR fuel channel designs so that they are representative of a practical application of supercritical water technology in nuclear plants. This loop will investigate various test section orientations which are the horizontal, vertical, and inclined to investigate buoyancy effects. Frictional pressure drop effects and satisfactory methods of estimating hydraulic resistances in supercritical fluid shall also be estimated with the loop. Operating limits for SPETA have been established to be able to capture the important heat transfer phenomena at supercritical conditions. Heat balance and flow calculations have

  4. An Experimental Investigation of Passive Variable-Pitch Vertical-Axis Ocean Current Turbine

    Directory of Open Access Journals (Sweden)

    Ridho Hantoro

    2011-04-01

    Full Text Available Vertical-axis hydrokinetic turbines with fixed pitch blades typically suffer from poor starting torque, low efficiency and shaking due to large fluctuations in both radial and tangential force with azimuth angle. Maximizing the turbine power output can be achieved only if the mechanism of generation of the hydrodynamic force on the blades is clearly identified and tools to design high-performance rotors are developed. This paper describes an initial experimental investigation to understand more of the performance on vertical-axis turbine related to the effect of fixed-pitch and passive variable-pitch application using airfoil NACA 0018. Comparative analysis according to aspects of rotation and tip speed ratios was discussed. Information regarding the changes of foil position in passive variable-pitch during rotation at a limited range of flow velocity variations test was obtained and analyzed.

  5. Drifting plasma collection by a positive biased tether wire in LEO-like plasma conditions: current measurement and plasma diagnostic

    OpenAIRE

    Siguier, Jean-Michel; Sarrailh, Pierre; Roussel, Jean-François; Inguimbert, Virgine; Murat, Gaël; Sanmartín Losada, Juan Ramón

    2013-01-01

    BETs is a three-year project financed by the Space Program of the European Commission, aimed at developing an efficient deorbit system that could be carried on board any future satellite launched into Low Earth Orbit (LEO). The operational system involves a conductive tape-tether left bare to establish anodic contact with the ambient plasma as a giant Langmuir probe. As a part of this project, we are carrying out both numerical and experimental approaches to estimate the collected current by ...

  6. Current Status of Clinical and Experimental Researches on Cognitive Impairment in Diabetes

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    This article reviews the clinical and experimental researches on cognitive impairment related to diabetes in the recent decade. Most clinical studies indicate that the cognitive impairment in patients with type 1 diabetes mellitus is related to recurrent hypoglycemia closely. There is little research about whether or not hyperglycemia is related to cognitive impairment in patients with type 1 diabetes mellitus. Most studies indicate that the cognitive impairment in type 2 diabetes involves multiple factors through multiple mechanisms, including blood glucose, blood lipid, blood pressure, level of insulin, medication, chronic complication, etc. But, there has been no large-scale, multi-center, randomized controlled clinical trial in China recently. And what is more, some problems exist in this field of research, such as the lack of golden criterion of cognitive function measurement, different population of studied objects, and incomprehensive handling of confounding factors. Experimental studies found that hippocampal long-term potentiation (LTP) was impaired,which were manifested by impairment of spatial memory and decreased expression of LTP, but its relation to hyperglycemia, the duration of diabetes, learning and memory has always been differently reported by different researches. Thus, there are a lot of unknown things to be explored and studied in order to clarify its mechanism. TCM has abundant clinical experience in treating cerebral disease with medicine that enforces the kidney and promotes wit. However, there has been no research on treating diabetic cognitive impairment,which requires work to be done actively and TCM to be put into full play, in order to improve the treatment of diabetes and enhance living quality of patients.

  7. 76 FR 64109 - Comment Request for Extension of a Currently Approved Information Collection: Labor Condition...

    Science.gov (United States)

    2011-10-17

    ... Collection: Labor Condition Application and Instructions for H-1B, H- 1B1, and E-3 Nonimmigrants; Forms ETA 9035, ETA 9035E and ETA 9035CP and WHD Nonimmigrant Worker Information Form WH-4, OMB Control No. 1205... respondents can be properly assessed. Through this notice, the Employment and Training Administration (ETA)...

  8. Current Control Method for Distributed Generation Power Generation Plants under Grid Fault Conditions

    DEFF Research Database (Denmark)

    Rodriguez, Pedro; Luna, Alvaro; Hermoso, Juan Ramon

    2011-01-01

    The operation of distributed power generation systems under grid fault conditions is a key issue for the massive integration of renewable energy systems. Several studies have been conducted to improve the response of such distributed generation systems under voltage dips. In spite of being less s...

  9. Homeworking: Home Office or Home Sweatshop? Report on Current Conditions of Homeworkers in Toronto's Garment Industry. NALL Working Paper.

    Science.gov (United States)

    Ng, Roxana; Wong, Renita Yuk-Lin; Choi, Angela

    The current conditions of home workers in the garment industry in Toronto, Canada, were examined through in-depth telephone interviews with 30 Chinese-speaking immigrant women who were employed as home workers in 1999. The paper dicusses the formal training and informal learning experiences of immigrant woman who are garment workers. A comparison…

  10. Experimental analysis of fuzzy controlled energy efficient demand controlled ventilation economizer cycle variable air volume air conditioning system

    Directory of Open Access Journals (Sweden)

    Rajagopalan Parameshwaran

    2008-01-01

    Full Text Available In the quest for energy conservative building design, there is now a great opportunity for a flexible and sophisticated air conditioning system capable of addressing better thermal comfort, indoor air quality, and energy efficiency, that are strongly desired. The variable refrigerant volume air conditioning system provides considerable energy savings, cost effectiveness and reduced space requirements. Applications of intelligent control like fuzzy logic controller, especially adapted to variable air volume air conditioning systems, have drawn more interest in recent years than classical control systems. An experimental analysis was performed to investigate the inherent operational characteristics of the combined variable refrigerant volume and variable air volume air conditioning systems under fixed ventilation, demand controlled ventilation, and combined demand controlled ventilation and economizer cycle techniques for two seasonal conditions. The test results of the variable refrigerant volume and variable air volume air conditioning system for each techniques are presented. The test results infer that the system controlled by fuzzy logic methodology and operated under the CO2 based mechanical ventilation scheme, effectively yields 37% and 56% per day of average energy-saving in summer and winter conditions, respectively. Based on the experimental results, the fuzzy based combined system can be considered to be an alternative energy efficient air conditioning scheme, having significant energy-saving potential compared to the conventional constant air volume air conditioning system.

  11. Arsenic-induced phosphate limitation under experimental Early Proterozoic oceanic conditions

    Science.gov (United States)

    Chi Fru, Ernest; Hemmingsson, Christoffer; Holm, Mikaela; Chiu, Beverly; Iñiguez, Enrique

    2016-01-01

    Comparison of phosphorus concentrations associated with modern hydrothermal Fe(III)(oxyhydr)oxides and ancient Fe(III) oxide-rich iron formations, is used to estimate bioavailable Precambrian marine phosphorus (P) concentrations. This led to the proposition of a low dissolved P budget of ˜10-25% of present-day levels, before ˜1.9 billion years ago. Estimates incorporating ancient marine Si levels ≥ 0.67 mM instead suggested global dissolved P levels greater than today. Here we unite current experimental models that have considered NaCl solutions containing elevated dissolved Fe(II), Si, Ca2+ and Mg2+ ions in the incorporation of P in Precambrian marine Fe(III)(oxyhydr)oxides, in addition to arsenic as a hydrothermal proxy. We show that the coprecipitation of dissolved P and Fe(III)(oxyhydr)oxides from arsenic-rich marine waters produces an average P distribution coefficient of ˜0.072 (± 0.01) μM-1. This is comparable to the ˜ 0.07 μM-1 predicted for Fe(III)(oxyhydr)oxides in modern arsenic-rich, submarine hydrothermal settings, from which the lower Early Proterozoic dissolved marine P concentrations were predicted. As/P molar ratios below modern seawater ratios removed the negative feedback effect high Si impose on P scavenging by Fe(III)(oxyhydr)oxides. The binding of As(III) to Fe(III)(oxyhydr)oxides exhibits a lower competitive influence on P fixation. As(V) that likely became prominent in the surficially oxidized Early Proterozoic oceans induced dissolved P limitation because of preferential P sequestration at the expense of dissolved As(V) enrichment. The control of As on P scavenging by the precipitating Fe(III)(oxyhydr)oxides is strong regardless of common seawater cations (Mg2+ and Ca2+). The data suggest that the application of Si and Fe(III)(oxyhydr)oxides as an ancient seawater P proxy should consider chemical variability between depositional basins, taking into account the rather strong role hydrothermal arsenic has on the distribution of P in

  12. New hadronic currents in TAUOLA: for confrontation with the experimental data

    CERN Document Server

    Was, Z

    2012-01-01

    The status of implementation of new hadronic currents into the Monte Carlo system for simulation of tau-lepton production and decay in high-energy accelerator experiments is reviewed. Since the tau-lepton conference in 2010 substantial progress was achieved: (i) For the TAUOLA Monte Carlo generator of tau-lepton decays, automated and simultaneous use of many versions of form factors for the calculation of optional weights for fits was developed and checked to work in the Belle and BaBar software environment. Alternative parameterizations of hadronic currents based on the Resonance Chiral approach are available now. This was achieved for more than 88% of the total tau hadronic width. (ii) the TAUOLA universal interface based on HepMC (the C++ event record) is available. This is the case for C++ users of PHOTOS Monte Carlo for radiative corrections in decays, as well. An algorithm for weighted events to explore spin effects in analysis of hard processes was prepared. (iii) Kernels featuring a complete first-ord...

  13. New hadronic currents in TAUOLA: for confrontation with the experimental data

    Energy Technology Data Exchange (ETDEWEB)

    Was, Z. [Institute of Nuclear Physics, Polish Academy of Sciences, ul. Radzikowskiego 152, 31-342 Cracow (Poland); CERN, 1211 Geneva (Switzerland)

    2012-04-15

    The status of implementation of new hadronic currents into the Monte Carlo system for simulation of {tau}-lepton production and decay in high-energy accelerator experiments is reviewed. Since the {tau}-lepton conference in 2010 substantial progress was achieved: (i) For the TAUOLA Monte Carlo generator of {tau}-lepton decays, automated and simultaneous use of many versions of form factors for the calculation of optional weights for fits was developed and checked to work in the Belle and BaBar software environment. Alternative parameterizations of hadronic currents based on the Resonance Chiral approach are available now. This was achieved for more than 88% of the total {tau} hadronic width. (ii) the TAUOLA universal interface based on HepMC (the C++ event record) is available. This is the case for C++ users of PHOTOS Monte Carlo for radiative corrections in decays, as well. An algorithm for weighted events to explore spin effects in analysis of hard processes was prepared. (iii) Kernels featuring a complete first-order matrix element are available now for PHOTOS users interested in decays of Z and W bosons. New tests with different options of matrix elements for those and for K{sub l3} decays are available as well. Presented results illustrate the status of the projects performed in collaboration with Zofia Czyczula, Nadia Davidson, Tomasz Przedzinski, Olga Shekhovtsova, Elzbieta Richter-Was, Pablo Roig, Qingjun Xu and others.

  14. An Experimental Study on the Darrieus-Savonius Turbine for the Tidal Current Power Generation

    Science.gov (United States)

    Kyozuka, Yusaku

    The Darrieus turbine is popular for tidal current power generation in Japan. It is simple in structure with straight wings rotating around a vertical axis, so that it has no directionality against the motion of tidal flow which changes its direction twice a day. However, there is one defect in the Darrieus turbine; its small starting torque. Once it stops, a Darrieus turbine is hard to re-start until a fairly fast current is exerted on it. To improve the starting torque of the Darrieus turbine used for tidal power generation, a hybrid turbine, composed of a Darrieus turbine and a Savonius rotor is proposed. Hydrodynamic characteristics of a semi-circular section used for the Savonius bucket were measured in a wind tunnel. The torque of a two bucket Savonius rotor was measured in a circulating water channel, where four different configurations of the bucket were compared. A combined Darrieus and Savonius turbine was tested in the circulating water channel, where the effect of the attaching angle between Darrieus wing and Savonius rotor was studied. Finally, power generation experiments using a 48 pole electric generator were conducted in a towing tank and the power coefficients were compared with the results of experiments obtained in the circulating water channel.

  15. Effect of Catalytic Pyrolysis Conditions Using Pulse Current Heating Method on Pyrolysis Products of Wood Biomass

    Directory of Open Access Journals (Sweden)

    Sensho Honma

    2014-01-01

    Full Text Available The influence of catalysts on the compositions of char and pyrolysis oil obtained by pyrolysis of wood biomass with pulse current heating was studied. The effects of catalysts on product compositions were analyzed using GC-MS and TEM. The compositions of some aromatic compounds changed noticeably when using a metal oxide species as the catalyst. The coexistence or dissolution of amorphous carbon and iron oxide was observed in char pyrolyzed at 800°C with Fe3O4. Pyrolysis oil compositions changed remarkably when formed in the presence of a catalyst compared to that obtained from the uncatalyzed pyrolysis of wood meal. We observed a tendency toward an increase in the ratio of polyaromatic hydrocarbons in the pyrolysis oil composition after catalytic pyrolysis at 800°C. Pyrolysis of biomass using pulse current heating and an adequate amount of catalyst is expected to yield a higher content of specific polyaromatic compounds.

  16. Effect of Catalytic Pyrolysis Conditions Using Pulse Current Heating Method on Pyrolysis Products of Wood Biomass

    Science.gov (United States)

    Honma, Sensho; Hata, Toshimitsu; Watanabe, Takashi

    2014-01-01

    The influence of catalysts on the compositions of char and pyrolysis oil obtained by pyrolysis of wood biomass with pulse current heating was studied. The effects of catalysts on product compositions were analyzed using GC-MS and TEM. The compositions of some aromatic compounds changed noticeably when using a metal oxide species as the catalyst. The coexistence or dissolution of amorphous carbon and iron oxide was observed in char pyrolyzed at 800°C with Fe3O4. Pyrolysis oil compositions changed remarkably when formed in the presence of a catalyst compared to that obtained from the uncatalyzed pyrolysis of wood meal. We observed a tendency toward an increase in the ratio of polyaromatic hydrocarbons in the pyrolysis oil composition after catalytic pyrolysis at 800°C. Pyrolysis of biomass using pulse current heating and an adequate amount of catalyst is expected to yield a higher content of specific polyaromatic compounds. PMID:25614894

  17. Influence of Rayleigh-Bénard convection on electrokinetic instability in overlimiting current conditions

    Science.gov (United States)

    de Valença, Joeri C.; Kurniawan, Aziz; Wagterveld, R. Martijn; Wood, Jeffery A.; Lammertink, Rob G. H.

    2017-03-01

    We investigate the influence of buoyancy on electroconvection at an ion-exchange membrane in an aqueous electrolyte solution. Electrokinetic instabilities (EKIs) and Rayleigh-Bénard (RB) convection are both known to mix the appearing concentration gradient layer and overcome the limiting current arising from diffusional limitations. The different physics, as well as the interplay between them, are investigated by electrical, flow, and concentration characterization. In the buoyancy stable orientation, an EKI mixing layer, having a low concentration, grows till saturated size. In the buoyancy unstable orientation, RB occurs and dominates the advective transport due to the large system size. When current density i 5 ilim EKI starts before RB and hastens the onset of RB. Upon onset of RB, EKI is suppressed while the overall resistance is still decreased. The onset times of EKI and RB could be predicted using a simple diffusion-migration model based on Fick's second law.

  18. Experimental and Numerical Study of Wave-Induced Long-Shore Currents on A Mild Slope Beach

    Institute of Scientific and Technical Information of China (English)

    SUN Tao; TAO Jian-hua

    2005-01-01

    The long-shore current distribution on a mild slope beach is studied by combining the numerical model and the physical experiment. The experiments of long-shore currents under the action of regular and irregular waves are conducted on mild beaches with different slopes in a wave basin. A numerical model is established, which includes a wave propagation model, a wave breaking model and a long-shore current model. The validity of the numerical model is proved by the comparison of its results with the results of the experimental model. It is concluded that the wave-induced long-shore current is influenced significantly by the incident wave height, the wave angle and the beach slope. Its application to the Bohai Bay indicates that the wave-induced currents have the same order of magnitude as the tide currents in the near-shore zone of mill slope beach. In the design of wastewater outfall locations on a mild-slope beach with shallow water of the Bohai Bay, the position of the outfall should be 10 km away from the shoreline, which is outside of the surf-zone.

  19. NATO Reassurance and Nuclear Reductions: Creating the Conditions (Transatlantic Current, no. 2)

    Science.gov (United States)

    2012-01-01

    valid OMB control number. 1. REPORT DATE JAN 2012 2. REPORT TYPE 3. DATES COVERED 00-00-2012 to 00-00-2012 4. TITLE AND SUBTITLE NATO...but should include ambiguous sce- narios where more debate is needed. NATO is currently deciding how robust its next major exercise, Steadfast Jazz ...conventional conflict (de- signed in such a way as to ensure that NATO prepara- tions are not aimed at any particular country and cover all possible

  20. Wave-Current Conditions and Navigation Safety at an Inlet Entrance

    Science.gov (United States)

    2015-06-26

    Wind wave generation and growth, diffraction, reflection, dissipation due to bottom friction , white-capping and breaking, wave-current interaction...the Coriolis force, wind stress, wave stress, bottom stress, vegetation flow drag, bottom friction , wave roller, and turbulent diffusion. Governing...H s , m), spectral peak period ( pT , sec ) and mean wave direction ( , deg), wave steepness ( /H Ls p , where L p is the spectral peak wavelength

  1. Knock-in model of Dravet syndrome reveals a constitutive and conditional reduction in sodium current

    OpenAIRE

    Schutte, Ryan J.; Schutte, Soleil S.; Algara, Jacqueline; Barragan, Eden V.; Gilligan, Jeff; Staber, Cynthia; Savva, Yiannis A.; Smith, Martin A.; Reenan, Robert; O'Dowd, Diane K.

    2014-01-01

    Hundreds of mutations in the SCN1A sodium channel gene confer a wide spectrum of epileptic disorders, requiring efficient model systems to study cellular mechanisms and identify potential therapeutic targets. We recently demonstrated that Drosophila knock-in flies carrying the K1270T SCN1A mutation known to cause a form of genetic epilepsy with febrile seizures plus (GEFS+) exhibit a heat-induced increase in sodium current activity and seizure phenotype. To determine whether different SCN1A m...

  2. Survey on Current Conditions and Intention of Outbound Investment by Chinese Enterprises (Ⅱ)

    Institute of Scientific and Technical Information of China (English)

    China Council for the Promotion of International T

    2010-01-01

    @@ Situation of the Overseas Investments of Chinese Enterprises 1. Small scale of investments Of the respondent enterprise having made overseas in-vestments, those with an investment amount of less than one million USD account for 61%, and only ten of them made investments exceeding 100 million USD, accounting for only about 1%. It thus appears that the overall scale of current overseas investments of Chinese enterprises is small, and only a very few enterprises have made large scale overseas invest-ments.

  3. The Current Mental State of School Students in Online Learning Conditions

    Directory of Open Access Journals (Sweden)

    Kovalevskaya E.V.,

    2015-08-01

    Full Text Available This article discusses the results of a study of actual mental state of high school students who are active subjects of career self-determination in terms of interactive learning. There are four groups of methods of interactive training: psychological training, art therapy, cognitive, and game training. The main task, which is solved by a researcher in a formative experiment with the use of each of these methods, is to establish significant differences in health, activity and mood as the indicators of current mental state of students in the classroom. As a result, we found that the most significant improvements in the current mental state takes place when using art and game therapy, so these techniques should be used in groups of students with low motivation to work, as well as in the adverse psychological climate. Less significant was the improvement of the current mental state after psychological training due to the fact that this method allow to update and seek solutions to the most important intrapersonal issues and require the implementation of a deeper reflection

  4. Electronic health records and online medical records: an asset or a liability under current conditions?

    Science.gov (United States)

    Allen-Graham, Judith; Mitchell, Lauren; Heriot, Natalie; Armani, Roksana; Langton, David; Levinson, Michele; Young, Alan; Smith, Julian A; Kotsimbos, Tom; Wilson, John W

    2017-01-20

    Objective The aim of the present study was to audit the current use of medical records to determine completeness and concordance with other sources of medical information.Methods Medical records for 40 patients from each of five Melbourne major metropolitan hospitals were randomly selected (n=200). A quantitative audit was performed for detailed patient information and medical record keeping, as well as data collection, storage and utilisation. Using each hospital's current online clinical database, scanned files and paperwork available for each patient audited, the reviewers sourced as much relevant information as possible within a 30-min time allocation from both the record and the discharge summary.Results Of all medical records audited, 82% contained medical and surgical history, allergy information and patient demographics. All audited discharge summaries lacked at least one of the following: demographics, medication allergies, medical and surgical history, medications and adverse drug event information. Only 49% of records audited showed evidence the discharge summary was sent outside the institution.Conclusions The quality of medical data captured and information management is variable across hospitals. It is recommended that medical history documentation guidelines and standardised discharge summaries be implemented in Australian healthcare services.What is known about this topic? Australia has a complex health system, the government has approved funding to develop a universal online electronic medical record system and is currently trialling this in an opt-out style in the Napean Blue Mountains (NSW) and in Northern Queensland. The system was originally named the personally controlled electronic health record but has since been changed to MyHealth Record (2016). In Victoria, there exists a wide range of electronic health records used to varying degrees, with some hospitals still relying on paper-based records and many using scanned medical records. This

  5. A Survey on Current English Learning Condition of Senior Vocational School Students

    Institute of Scientific and Technical Information of China (English)

    AI Shan-shan

    2015-01-01

    The study aimed to investigate the relationship of students’English proficiency level and participation condition.70 students from National Senior Commercial & Industrial Vocational School participated in this study. The analysis method was one-way ANOVA, that is, one-way analysis of variance. The results showed that strategy and emotion participation influenced students’English proficiency level largely. In the end, the results were discussed and some pedagogical implications and sugges⁃tions for further study were also presented.

  6. Forecasting of the electrical actuators condition using stator’s current signals

    Science.gov (United States)

    Kruglova, T. N.; Yaroshenko, I. V.; Rabotalov, N. N.; Melnikov, M. A.

    2017-02-01

    This article describes a forecasting method for electrical actuators realized through the combination of Fourier transformation and neural network techniques. The method allows finding the value of diagnostic functions in the iterating operating cycle and the number of operational cycles in time before the BLDC actuator fails. For forecasting of the condition of the actuator, we propose a hierarchical structure of the neural network aiming to reduce the training time of the neural network and improve estimation accuracy.

  7. Experimental Investigation of Soil and Atmospheric Conditions on the Momentum, Mass, and Thermal Boundary Layers Above the Land Atmosphere Interface

    Science.gov (United States)

    Trautz, A.; Smits, K. M.; Illangasekare, T. H.; Schulte, P.

    2014-12-01

    The purpose of this study is to investigate the impacts of soil conditions (i.e. soil type, saturation) and atmospheric forcings (i.e. velocity, temperature, relative humidity) on the momentum, mass, and temperature boundary layers. The atmospheric conditions tested represent those typically found in semi-arid and arid climates and the soil conditions simulate the three stages of evaporation. The data generated will help identify the importance of different soil conditions and atmospheric forcings with respect to land-atmospheric interactions which will have direct implications on future numerical studies investigating the effects of turbulent air flow on evaporation. The experimental datasets generated for this study were performed using a unique climate controlled closed-circuit wind tunnel/porous media facility located at the Center for Experimental Study of Subsurface Environmental Processes (CESEP) at the Colorado School of Mines. The test apparatus consisting of a 7.3 m long porous media tank and wind tunnel, were outfitted with a sensor network to carefully measure wind velocity, air and soil temperature, relative humidity, soil moisture, and soil air pressure. Boundary layer measurements were made between the heights of 2 and 500 mm above the soil tank under constant conditions (i.e. wind velocity, temperature, relative humidity). The soil conditions (e.g. soil type, soil moisture) were varied between datasets to analyze their impact on the boundary layers. Experimental results show that the momentum boundary layer is very sensitive to the applied atmospheric conditions and soil conditions to a much less extent. Increases in velocity above porous media leads to momentum boundary layer thinning and closely reflect classical flat plate theory. The mass and thermal boundary layers are directly dependent on both atmospheric and soil conditions. Air pressure within the soil is independent of atmospheric temperature and relative humidity - wind velocity and soil

  8. Conditional short-crested waves in shallow water and with superimposed current

    DEFF Research Database (Denmark)

    Jensen, Jørgen Juncher

    2002-01-01

    For bottom-supported offshore structures like oil drilling rigs and oil production platforms, a deterministic design wave approach is often applied using a regular non-linear Stokes´ wave. Thereby, the procedure accounts for non-linear effects in the wave loading but the randomness of the ocean...... wave, given the value of the wave crest at a specific point in time or space. In the present paper a derivation of the expected linear short-crested wave riding on a uniform current is given. The analysis is based on the conventional shallow water Airy wave theory and the direction of the main wind...

  9. Current signature analysis for condition monitoring of cage induction motors industrial application and case histories

    CERN Document Server

    Thomson, William T

    2017-01-01

    This book has 13 chapters and contains a unique database of 50 industrial case histories on theapplication of MCSA to diagnose broken rotor bars or unacceptable levels of airgap eccentricity in cage induction motors with ratings from 127 kW (170 H.P.) to 10,160 kW (13,620 H.P.). There are also unsuccessful case histories which is another unique feature of the book. The case studies also illustrate the effects of mechanical load dynamics downstream of the motor on the interpretation of current signatures. A number of cases are presented where abnormal operation of the driven loadwas diagnosed.

  10. Eddy Current Minimizing Flow Plug for Use in Flow Conditioning and Flow Metering

    Science.gov (United States)

    England, John Dwight (Inventor); Kelley, Anthony R. (Inventor)

    2015-01-01

    An eddy-current-minimizing flow plug has open flow channels formed between the plug's inlet and outlet. Each open flow channel includes (i) a first portion that originates at the inlet face and converges to a location within the plug that is downstream of the inlet, and (ii) a second portion that originates within the plug and diverges to the outlet. The diverging second portion is approximately twice the length of the converging first portion. The plug is devoid of planar surface regions at its inlet and outlet, and in fluid flow planes of the plug that are perpendicular to the given direction of a fluid flowing therethrough.

  11. A condition for small bootstrap current in three-dimensional toroidal configurations

    Energy Technology Data Exchange (ETDEWEB)

    Mikhailov, M. I., E-mail: mikhaylov-mi@nrcki.ru [National Russian Research Center Kurchatov Institute (Russian Federation); Nührenberg, J.; Zille, R. [Max-Planck-Institut für Plasmaphysik (Germany)

    2016-11-15

    It is shown that, if the maximum of the magnetic field strength on a magnetic surface in a threedimensional magnetic confinement configuration with stellarator symmetry constitutes a line that is orthogonal to the field lines and crosses the symmetry line, then the bootstrap current density is smaller compared to that in quasi-axisymmetric (qa) [J. Nührenberg et al., in Proc. of Joint Varenna−Lausanne Int. Workshop on Theory of Fusion Plasmas, Varenna, 1994, p. 3] and quasi-helically (qh) symmetric [J. Nührenberg and R. Zille, Phys. Lett. A 129, 113 (1988)] configurations.

  12. Highlighting and trying to overcome a serious drawback with QSPR studies; data collection in different experimental conditions (mixed-QSPR).

    Science.gov (United States)

    Beheshti, Abolghasem; Riahi, Siavash; Ganjali, Mohammad Reza; Norouzi, Parviz

    2012-03-15

    The experimental conditions in quantitative structure-property relationship (QSPR) studies need to be the same for each dataset in case one wishes to relate the property, only to the structure. This major drawback limits QSPR studies due to two reasons: (1) Gathering of physicochemical data obtained under the same experimental condition is difficult. (2) The obtained model is just useful to predict the physicochemical properties under the specific experimental condition. In this article, we report an attempt to highlight the shortcoming of QSPR studies for a property that was measured under different experimental conditions. In addition, we reveal inadequacies that correlating the fluorescence properties and the descriptor of the solvent has. These defects are eventually removed by taking into account the solvent-solute interactions in descriptor calculations. Quantum chemical calculations (HF/6-31G*) were carried out to optimize geometry and calculate the structural descriptors. The genetic algorithm combined with multiple linear regression method was utilized to construct the linear QSPR models. Because of the better nonlinear relationship between the quantum yield of fluorescence and structural descriptors in comparison with those of a linear relationship, support vector machine was used to construct the nonlinear QSPR model. Result analyses demonstrated that the proposed models meet our goal.

  13. Effect of an experimental zirconia-silica coating technique on micro tensile bond strength of zirconia in different priming conditions

    NARCIS (Netherlands)

    Chen, C.; Kleverlaan, C.J.; Feilzer, A.J.

    2012-01-01

    Objectives This study aimed to evaluate the adhesive properties of a MDP-containing resin cement to a colored zirconia ceramic, using an experimental zirconia-silica coating technique with different priming conditions. Methods 18 zirconia ceramic discs (Cercon base colored) were divided into two gro

  14. Experimental Estimating Deflection of a Simple Beam Bridge Model Using Grating Eddy Current Sensors

    Directory of Open Access Journals (Sweden)

    Hui Zhao

    2012-07-01

    Full Text Available A novel three-point method using a grating eddy current absolute position sensor (GECS for bridge deflection estimation is proposed in this paper. Real spatial positions of the measuring points along the span axis are directly used as relative reference points of each other rather than using any other auxiliary static reference points for measuring devices in a conventional method. Every three adjacent measuring points are defined as a measuring unit and a straight connecting bar with a GECS fixed on the center section of it links the two endpoints. In each measuring unit, the displacement of the mid-measuring point relative to the connecting bar measured by the GECS is defined as the relative deflection. Absolute deflections of each measuring point can be calculated from the relative deflections of all the measuring units directly without any correcting approaches. Principles of the three-point method and displacement measurement of the GECS are introduced in detail. Both static and dynamic experiments have been carried out on a simple beam bridge model, which demonstrate that the three-point deflection estimation method using the GECS is effective and offers a reliable way for bridge deflection estimation, especially for long-term monitoring.

  15. Structural Characterization of Phase Separation in Fe-Cr: A Current Comparison of Experimental Methods

    Science.gov (United States)

    Xu, Xin; Odqvist, Joakim; Colliander, Magnus Hörnqvist; Thuvander, Mattias; Steuwer, Axel; Westraadt, Johan E.; King, Stephen; Hedström, Peter

    2016-12-01

    Self-assembly due to phase separation within a miscibility gap is important in numerous material systems and applications. A system of particular interest is the binary alloy system Fe-Cr, since it is both a suitable model material and the base system for the stainless steel alloy category, suffering from low-temperature embrittlement due to phase separation. Structural characterization of the minute nano-scale concentration fluctuations during early phase separation has for a long time been considered a major challenge within material characterization. However, recent developments present new opportunities in this field. Here, we present an overview of the current capabilities and limitations of different techniques. A set of Fe-Cr alloys were investigated using small-angle neutron scattering (SANS), atom probe tomography, and analytical transmission electron microscopy. The complementarity of the characterization techniques is clear, and combinatorial studies can provide complete quantitative structure information during phase separation in Fe-Cr alloys. Furthermore, we argue that SANS provides a unique in-situ access to the nanostructure, and that direct comparisons between SANS and phase-field modeling, solving the non-linear Cahn Hilliard equation with proper physical input, should be pursued.

  16. Experimental investigation of a forced response condition in a multistage compressor

    Science.gov (United States)

    Murray, William Louis, III

    The objective of this research is twofold. Firstly, the design, development, and construction of a test facility for a Honeywell APU-style centrifugal compressor was implemented, as well as the design and construction of an inlet flow experiment. Secondly, the aeromechanical response of an embedded stage in the Purdue 3-Stage axial research compressor was analyzed through a suite of different measurement techniques in the fulfillment of the end of the GUIde IV Consortium contract. The purpose of the first phase of Honeywell work was to comprehensively measure the flow field of an APU-style centrifugal compressor inlet through the use of Laser Doppler Velocimetry (LDV). A portion of a Honeywell supplied inlet was modified to provide optical access to the elbow, and a gas ejector system was designed and constructed to provide the same suction to the inlet that it would see during operation with the compressor. A performance and health monitoring electronics system was designed and purchased to support the testing of the Honeywell inlet ejector system and eventually it will be used for testing with a centrifugal compressor. Additionally, a secondary air and oil system has been designed and is currently being constructed in the test cell in preparation for the arrival of the Honeywell compressor this summer. An embedded rotor stage in the Purdue 3-stage compressor, with a Campbell diagram crossing of the 1T vibratory mode was analyzed with a suite of measurement systems. In addition to steady state compressor performance measurements, other types of measurements were used to characterize the aerodynamic forcing function for this forced response condition including: NSMS, high-frequency pressure transducers mounted in the casing and in a downstream stator, and cross-film thermal anemometry. Rotor geometry was measured by Aerodyne using an in-situ laser scanning technique. Vibrometry testing was performed at WPAFB to characterize safe operating speeds for stator

  17. Problems of software financial resources agrarian sector in the current economic conditions of management

    Directory of Open Access Journals (Sweden)

    Grischuk Nadiya Viktorivna

    2016-12-01

    Full Text Available Research of financial science on questions providing of financial resources does not exhaust and needs a further study that acquires new descriptions and vectors of development constantly, what costing illuminations in the conditions of present time. Research of the state of provision of financial resources agrarian to the sector of economy with allocating of main segment – loan and attracted financial resources, today topically. In the article the essence funds are considered sources of agricultural enterprises financial resources and problems associated with the formation and use of financial resources in the modern world. Also the problems arising in improving the process of raising funds agricultural enterprises. Revealed that an effective tool to attract financial resources is the issue of convertible bonds and the introduction of agricultural receipts. It is well-proven that in the conditions of unstable environment forward development of the system of agrarian relations must be carried out on the basis of the government programs, and normatively-legal adjusting that take into account not only the existent state of affairs at the market of agroindustrial products but also economic provision of enterprises national agrarian to the sector.

  18. Effect of Doubly Fed Induction GeneratorTidal Current Turbines on Stability of a Distribution Grid under Unbalanced Voltage Conditions

    Directory of Open Access Journals (Sweden)

    Dahai Zhang

    2017-02-01

    Full Text Available This paper analyses the effects of doubly fed induction generator (DFIG tidal current turbines on a distribution grid under unbalanced voltage conditions of the grid. A dynamic model of an electrical power system under the unbalanced network is described in the paper, aiming to compare the system performance when connected with and without DFIG at the same location in a distribution grid. Extensive simulations of investigating the effect of DFIG tidal current turbine on stability of the distribution grid are performed, taking into account factors such as the power rating, the connection distance of the turbine and the grid voltage dip. The dynamic responses of the distribution system are examined, especially its ability to ride through fault events under unbalanced grid voltage conditions. The research has shown that DFIG tidal current turbines can provide a good damping performance and that modern DFIG tidal current power plants, equipped with power electronics and low-voltage ride-through capability, can stay connected to weak electrical grids even under the unbalanced voltage conditions, whilst not reducing system stability.

  19. INCREASE THE RESOURCE OF CURRENT COLLECTOR ELEMENTS OF THE ELECTRIFIED HIGH-SPEED TRANSPORT IN OPERATING CONDITIONS

    Directory of Open Access Journals (Sweden)

    Y. L. Bolshakov

    2015-07-01

    Full Text Available Purpose. The paper is aimed to determinate the main ways of increasing resource efficiency and exploitation of coal current collector surface inserts of speed electric rolling stock. Methodology. The research is based on the technique relies on the use of theory regulations of technical systems reliability, electromechanical processes, theory of statistics. Findings. The existing approaches to the production of current collector surface inserts in Europe and Ukraine were considered, a number of information sources was analyzed. The most effective ways of increasing current carrying capacity and wear resistance of current collector elements were determined. It has been established that the existing system for determining the quality of manufacturing of current collector elements have a number of drawbacks that make it difficult to control the input and makes diagnosing current collecting elements in operation impossible. On the basis of the facts, for the needs of the locomotive depot, we propose a new booth allowing avoiding the existing difficulties with diagnosing of current collector elements. During the study were established pervasive transgressions of technological standards of service pantographs. Originality. Based on the results of operational research carried out on the basis of the locomotive depot, obtained depending, based on which, it is proposed to introduce an operative diagnosing system of the current collector elements state during operation. In the course of a comparative analysis of existing and perspective development directions of current collector elements with high load current carrying capacity and durability, were definited constructive conditions for the optimal ratio is inserts. It was established that a significant proportion of failures occur due to imperfect maintenance system for which, on the basis of operational data, recommendations were developed. Practical value. Obtained results of the information sources

  20. Current radiological techniques used to evaluate unilateral partial ureteral obstruction: an experimental rabbit study.

    Science.gov (United States)

    Yazıcı, Mehmet; Celebi, Suleyman; Kuzdan, Özgür; Koçan, Hüseyin; Ayyıldız, Halil Suat; Bayrak, İlkay Koray; Bilgici, Meltem Ceyhan; Yapıcı, Oktay; Kefeli, Mehmet; Arıtürk, Ender

    2015-07-01

    The aim of this study was to evaluate functional and prognostic benefits of Doppler ultrasonography (DU), diuretic renal scintigraphy (DRS), and magnetic resonance urography (MRU) during diagnosis and follow-up of ureteropelvic junction obstruction (UPJO) and to examine apoptosis rates caused by UPJO in an experimental rabbit model. Twenty-four rabbits were divided randomly into two groups. The left kidneys of 15 rabbits from the first group underwent Ulm-Miller surgery to create UPJO, whereas the left kidneys of nine rabbits from the second group underwent sham surgery. A pressure flow study (Whitaker's test) was done during postoperative week 6. Based on the Whitaker test, the DU, DRS, and MRU findings were compared. The number of apoptotic renal cells was counted after death. The Whitaker test run during postoperative week 6 revealed obstructions in 15 rabbits from group 1; the nine rabbits of the sham group had no obstructions. Sensitivity and specificity of DRS were 93.3 and 88.8 %, respectively, and those of MRU were 93.3 and 88.8 %, respectively. The postoperative mean RI values were significantly higher than the preoperative values, associated with sensitivity of 86.6 % and specificity of 77.5 % for detecting UPJO. DRS, MRU, and RI could not predict UPJO in one (8 %), one (8 %), and two (16 %) kidneys, respectively. Likelihood ratio (LR) was 8.4 for MRU and scintigraphy, while for RI, LR was 3.9. Pathology specimens revealed that all kidneys with UPJO underwent apoptosis, and the number of apoptotic cells was significantly higher on the UPJO-created side than on the contralateral and in the sham group (p < 0.05). No test predicted all apoptosis related to UPJO. The RI, DRS, and DMRU results correlated with the pressure flow results for detecting UPJO. No single radiological technique predicted all initial UPJO-created kidneys that concluded with apoptosis. Further studies are required to seek with better methods for diagnosing an obstruction or to define a

  1. Polyethylene glycol-induced internalization of bacteria into fungal protoplasts: Electron microscopic study and optimization of experimental conditions

    Energy Technology Data Exchange (ETDEWEB)

    Guerra-Tschuschke, I.; Martin, I.; Gonzalez, M.T. (Univ. de Granada, (Spain))

    1991-05-01

    The authors studied the mechanism of internalization of Escherichia coli into Saccharomyces cerevisiae induced by polyethylene glycol (PEG) and optimized the experimental conditions. Transmission electron microscope studies revealed that the principal factor involved in the internalization was the degree of cell aggregation attained. Internalization occurred mainly by an endocytosis-like mechanism and took place during the elimination of PEG. The optimum conditions were to treat a mixed pellet of both microorganisms with 15% PEG and then gradually dilute the polymer. The same conditions were applied to E. coli and Aspergillus nidulans, with similar results.

  2. THE INFLUENCE OF ENVIRONMENTAL FACTORS ON THE ROMANIAN BANKING MANAGEMENT IN CURRENT CONDITIONS

    Directory of Open Access Journals (Sweden)

    CIURLĂU LOREDANA

    2013-05-01

    Full Text Available In the context of the financial crisis, the imbalance on the maturity of loans and financing resources and default dependence on foreign sources, ensuring the liquidity of the banking system in Romania has depended to a significant measure of confidence of domestic depositors and foreign investors in the banks and their willingness to renew funding to maturity. Despite the presence of corporate companies, banks as credit institutions is insufficiently developed, the complex mechanisms of the lacks. The current major challenges of the banking system are determined by: the legal framework; innovation of technology, economic volatility, changing expectations of clients and staff, as well as the adoption of new technologies make it increasingly difficult for banks to discover technological alternatives, strategy and prioritization of investments in technology; globalization.

  3. Technology Commercialisation in a Developing Country: Current Condition and Its Challenge in Indonesia

    Directory of Open Access Journals (Sweden)

    Wawan Dhewanto

    2012-01-01

    Full Text Available Innovation is considered the main engine of economic growth in both developed and developing countries. Despite the important role of innovation, little has been understood about technology transfer becoming a commercial success in developing countries, especially in the Indonesian context. The purpose of this paper is to identify technology commercialisation activities in Indonesia. Based on secondary data sources, an analysis of the current state regarding the issue is constructed. The findings in this paper suggest that technology commercialisation in Indonesia is initiated at the levels of university, government research institution, and corporate. This study provides insights for policy makers, business leaders, and university administrators into the appropriate roles of institutions and organisations in promoting and assisting technology commercialisation activities of their respective inventors.Key words: Technology commercialisation, developing country, university, government research institution, corporate

  4. Conditional Short-crested second order waves in shallow water and with superimposed current

    DEFF Research Database (Denmark)

    Jensen, Jørgen Juncher

    2004-01-01

    wave, given the value of the wave crest at a specific point in time or space. In the present paper a derivation of the expected second order short-crested wave riding on a uniform current is given. The analysis is based on the second order Sharma and Dean shallow water wave theory and the direction......For bottom-supported offshore structures like oil drilling rigs and oil production platforms, a deterministic design wave approach is often applied using a regular non-linear Stokes' wave. Thereby, the procedure accounts for non-linear effects in the wave loading but the randomness of the ocean...... waves is poorly represented, as the shape of the wave spectrum does not enter the wave kinematics. To overcome this problem and still keep the simplicity of a deterministic approach, Tromans, Anaturk and Hagemeijer (1991) suggested the use of a deterministic wave, defined as the expected linear Airy...

  5. Relation between Wind and Wind Currents on the Synoptic Scale with Account of Wave Conditions

    CERN Document Server

    Polnikov, Vladislav

    2011-01-01

    A version of model is proposed, which is aimed for getting parameters of the atmospheric layer and upper water layer with account of the wind-wave state. The dynamics of the atmospheric boundary layer is realized in version of papers [1, 2], and the dynamics of the upper layer is realized in the framework of Ekman layers in the atmosphere and the sea [3]. In the latter case, the Kitaigorodskii [4, 5] approach was used for describing the dynamics of the air-water interface. The key parameters of the atmospheric layer and upper water layer (the friction velocity and the speed of drift currents) are calculated for typical wind-wave situations. Satisfactory quantitative agreement between calculated and traditionally observed values is shown.

  6. [Pathological buying. A review of the current knowledge regarding this condition of behavioral excess].

    Science.gov (United States)

    Müller, A; de Zwaan, M

    2010-04-01

    Compulsive buying is characterized by frequent excessive purchasing of items that are primarily not needed or used. The compulsive buying behavior results in mental, social, financial and often legal problems. Although compulsive buying affects a significant percentage of the general population and has received increasing attention in research, it has largely been ignored in clinical practice. Compulsive buying disorder is currently conceptualized as an"impulse control disorder not otherwise specified". However, the appropriate classification continues to be debated. Compulsive buying is associated with significant psychiatric co-morbidity, especially with depressive, anxiety, obsessive-compulsive, substance use, personality, and other impulse control disorders. Small controlled trials failed to confirm the efficacy of antidepressants in the treatment of compulsive buying disorder, whereas early evidence suggests that cognitive behavioral therapy is helpful in alleviating compulsive buying symptoms. Further research is needed to establish a better understanding of etiology, classification, and treatment strategies.

  7. CALCULATION-EXPERIMENTAL METHOD OF RESEARCH IN A METALLIC CONDUCTOR WITH THE PULSE CURRENT OF ELECTRONIC WAVEPACKAGES AND DE BROGLIE ELECTRONIC HALF-WAVES

    Directory of Open Access Journals (Sweden)

    M. I. Baranov

    2016-12-01

    Full Text Available Purpose. Development of calculation-experimental method for a discovery and study of electronic wavepackages (EWP and of de Broglie electronic half-waves in a metallic conductor with the pulse axial-flow current of high density. Methodology. Theoretical bases of the electrical engineering, bases of quantum physics, electrophysics bases of technique of high voltage and large pulsecurrents, and also bases of technique of measuring of permanent and variable electric value. Results. On the basis of generalization of results of research of features of the longitudinal wave periodic distributing of negatively charged transmitters of electric current of conductivity in the thin round continuous zincked steel wire offered and approved in the conditions of high-voltage laboratory method for a discovery and direct determination in him of geometrical parameters of «hot» and «cold» longitudinal areas quantized periodic longitudinal EWP and accordingly the mediated determination of values of the quantized lengths formative their de Broglie electronic half-waves. It is shown that results of close quantum mechanical calculations of EWP and quantized lengths λenz/2 of longitudinal de Broglie half-waves for the probed wire long l0 well comport with the results of the executed high temperature experiments on the powerful high-voltage generator of homopolar large pulse current of millisecond duration. Originality. First calculation-experimental a way the important for the theory of electricity fact of existence is set in a round metallic explorer with the impulsive axial-flow current of the quantized coherent de Broglie electronic half-waves, amplitudes of which at the quantum number of n=1,3,9 correspond the middles of «hot» longitudinal areas of EWP. Calculation quantum mechanical correlation of type of λenz/2=l0/n got experimental confirmation, in obedience to which on length of l0 conductor the integer of quantized electronic half-waves is always laid

  8. The local property taxes and municipal federalism. Current and future inequity condition of Italian Property Taxation

    Directory of Open Access Journals (Sweden)

    Michele Argiolas

    2013-08-01

    Full Text Available The main purpose of this paper is to analyze and compare the current local tax on real estate and the future and assessing criticality. The tax base is calculated by applying calculation methods that differ depending on the type of property you must tax. For buildings used for residential, the tax base is calculated on the basis of the cadastral income; in the case of building land is rather used the market value of land and buildings and, for rent, rural manor. The land property values are always lower than market values, which is because some time trying to implement a revision of the class with the objective of bringing the two values. The reclass procedure has recently been adopted in the municipality of Milano where it was decided to reclass of buildings located within a few micro-climates for the most central, in which houses were originally built affordable housing to meet the housing needs of the social classes poor and that over time turned into mansions in the city center. From 1 January 2012, the Imu will come into force, only municipal tax, which replaces the current Ici; the two taxes differ in the higher fixed rate (7.6 ‰, which does not involve substantial modifications to the old system tax. In this way, the result will be to produce an increase in the tax burden without solving the inequalities of the old system but increasing the gap. The Implementation Act contains provisions which IMU when applied to allow municipalities to solve some problems present in the Ici.

  9. Current and future experimental strategies for structural analysis of trichothecene mycotoxins--a prospectus.

    Science.gov (United States)

    Shank, Roxanne A; Foroud, Nora A; Hazendonk, Paul; Eudes, François; Blackwell, Barbara A

    2011-12-01

    Fungal toxins, such as those produced by members of the order Hypocreales, have widespread effects on cereal crops, resulting in yield losses and the potential for severe disease and mortality in humans and livestock. Among the most toxic are the trichothecenes. Trichothecenes have various detrimental effects on eukaryotic cells including an interference with protein production and the disruption of nucleic acid synthesis. However, these toxins can have a wide range of toxicity depending on the system. Major differences in the phytotoxicity and cytotoxicity of these mycotoxins are observed for individual members of the class, and variations in toxicity are observed among different species for each individual compound. Furthermore, while diverse toxicological effects are observed throughout the whole cellular system upon trichothecene exposure, the mechanism of toxicity is not well understood. In order to comprehend how these toxins interact with the cell, we must first have an advanced understanding of their structure and dynamics. The structural analysis of trichothecenes was a subject of major interest in the 1980s, and primarily focused on crystallographic and solution-state Nuclear Magnetic Resonance (NMR) spectroscopic studies. Recent advances in structural determination through solution- and solid-state NMR, as well as computation based molecular modeling is leading to a resurgent interest in the structure of these and other mycotoxins, with the focus shifting in the direction of structural dynamics. The purpose of this work is to first provide a brief overview of the structural data available on trichothecenes and a characterization of the methods commonly employed to obtain such information. A summary of the current understanding of the relationship between structure and known function of these compounds is also presented. Finally, a prospectus on the application of new emerging structural methods on these and other related systems is discussed.

  10. Current and Future Experimental Strategies for Structural Analysis of Trichothecene Mycotoxins—A Prospectus

    Directory of Open Access Journals (Sweden)

    Barbara A. Blackwell

    2011-12-01

    Full Text Available Fungal toxins, such as those produced by members of the order Hypocreales, have widespread effects on cereal crops, resulting in yield losses and the potential for severe disease and mortality in humans and livestock. Among the most toxic are the trichothecenes. Trichothecenes have various detrimental effects on eukaryotic cells including an interference with protein production and the disruption of nucleic acid synthesis. However, these toxins can have a wide range of toxicity depending on the system. Major differences in the phytotoxicity and cytotoxicity of these mycotoxins are observed for individual members of the class, and variations in toxicity are observed among different species for each individual compound. Furthermore, while diverse toxicological effects are observed throughout the whole cellular system upon trichothecene exposure, the mechanism of toxicity is not well understood. In order to comprehend how these toxins interact with the cell, we must first have an advanced understanding of their structure and dynamics. The structural analysis of trichothecenes was a subject of major interest in the 1980s, and primarily focused on crystallographic and solution-state Nuclear Magnetic Resonance (NMR spectroscopic studies. Recent advances in structural determination through solution- and solid-state NMR, as well as computation based molecular modeling is leading to a resurgent interest in the structure of these and other mycotoxins, with the focus shifting in the direction of structural dynamics. The purpose of this work is to first provide a brief overview of the structural data available on trichothecenes and a characterization of the methods commonly employed to obtain such information. A summary of the current understanding of the relationship between structure and known function of these compounds is also presented. Finally, a prospectus on the application of new emerging structural methods on these and other related systems is

  11. Experimental study on two-phase gas-liquid flow patterns at normal and reduced gravity conditions

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Experimental studies have been performed for horizontal two-phase air-water flows at nor-mal and reduced gravity conditions in a square cross-section channel. The experiments at reducedgravity are conducted on board the Russian IL-76 reduced gravity airplane. Four flow patterns, namelybubble, slug, slug-annular transition and annular flows, are observed depending on the liquid and gassuperficial velocities at both conditions. Semi-theoretical Weber number model is developed to includethe shape influence on the slug-annular transition. It is shown that its prediction is in reasonable agree-ment with the experimental slug-annular transition under both conditions. For the case of two-phasegas-liquid flow with large value of the Froude number, the drift-flux model can predict well the observedboundary between bubble and slug flows.

  12. Are current disease-modifying therapeutics in multiple sclerosis justified on the basis of studies in experimental autoimmune encephalomyelitis?

    Science.gov (United States)

    Farooqi, Nasr; Gran, Bruno; Constantinescu, Cris S

    2010-11-01

    The precise aetio-pathology of multiple sclerosis remains elusive. However, important recent advances have been made and several therapies have been licensed for clinical use. Many of these were developed, validated or tested in the animal model, experimental autoimmune encephalomyelitis (EAE). This systematic review aims to assess whether the current disease modifying treatments and those that are the closest to the clinic are justified on the basis of the results of EAE studies. We discuss some aspects of the utility and caveats of EAE as a model for multiple sclerosis drug development.

  13. Experimental Condition - Arabidopsis Phenome Database | LSDB Archive [Life Science Database Archive metadata

    Lifescience Database Archive (English)

    Full Text Available phenotypes - Light condition etc. Plant Environment Ontology (EO) is used for standardization. - Existence .../togodb.biosciencedbc.jp/togodb/view/cpp_exp_condition#en Data acquisition method Plant Environment Ontolo...gy, ChEBI Data analysis method - Number of data entries 22 entries Data item Descri

  14. Conditions for the Validity of Faraday's Law of Induction and Their Experimental Confirmation

    Science.gov (United States)

    Lopez-Ramos, A.; Menendez, J. R.; Pique, C.

    2008-01-01

    This paper, as its main didactic objective, shows the conditions needed for the validity of Faraday's law of induction. Inadequate comprehension of these conditions has given rise to several paradoxes about the issue; some are analysed and solved in this paper in the light of the theoretical deduction of the induction law. Furthermore, an…

  15. Combining Experimental Petrology and 3D Imaging to Gain Insight into Syn-eruptive Conditions of the Bishop Tuff, California

    Science.gov (United States)

    Chattin, Archer; Pamukcu, Ayla; Gardner, James; Gualda, Guilherme

    2015-04-01

    The Bishop tuff is a rhyolitic ignimbrite deposited by a supereruption 0.76 million years ago that formed the Long Valley Caldera in California, USA. Pamukcu et. al (2012) identifies two distinct crystal populations present in the Bishop Tuff, the first being a long-lived, large phenocryst population that records storage conditions, and the second a rapidly nucleated, quickly staunched microlite population thought to result from eruptive decompression. Laboratory experiments to reproduce this quickly grown population may help constrain the conditions and rates under which decompression took place. Rapid nucleation of microlites is accompanied by just as rapid bubble nucleation when volatiles exsolve during decompression; the size distribution of vesicles in eruptive products may thus provide important information on syn-eruptive processes. In this study we combine information from vesicle size distributions on natural pumice with data on experimentally produced microlite crystals with the goal of better understanding the syn-eruptive evolution of a supereruption-forming magma body. Decompression experiments are run using a natural Bishop tuff pumice clast ground and melted in the presence of water to obtain a melt representative of late-erupted Bishop Tuff (LBT) magmas. Experimental charges were subjected to decompression at varying rates and initial temperatures. At this time five experiments have been completed. All decompression experiments start at 130MPa, consistent with water concentration in LBT glass inclusions, and end at 10 MPa. Initial temperatures are either 710°C or 785°C, while decompression rates are 20 MPa/hr, 5.5MPa/hr, or 1.7MPa/hr Experimental products were compared to natural products using Scanning Electron Microscopy to document eventual crystal rims and microlites. We have been successful in causing limited feldspar crystallization, but have yet to generate quartz microlites. Bubble size distributions are obtained by analyzing x

  16. Experimental data and boundary conditions for a Double - Skin Facade building in preheating mode

    DEFF Research Database (Denmark)

    Larsen, Olena Kalyanova; Heiselberg, Per; Jensen, Rasmus Lund

    was carried out in a full scale test facility ‘The Cube’, in order to compile three sets of high quality experimental data for validation purposes. The data sets are available for preheating mode, external air curtain mode and transparent insulation mode. The objective of this article is to provide the reader......’. This covers such problem areas as measurements of naturally induced air flow, measurements of air temperature under direct solar radiation exposure, etc. Finally, in order to create a solid foundation for software validation, the uncertainty and limitations in the experimental results are discussed. In part...

  17. The effects of scope condition-based participant exclusion on experimental outcomes in expectation states research: A meta-analysis.

    Science.gov (United States)

    Dippong, Joseph

    2012-03-01

    Expectation states theory employs several scope statements to specify the situational conditions that must be met for any test of the theory to be considered valid (Foschi, 1997). Collective orientation and task orientation are two scope conditions that researchers frequently implement as selection criteria for a participant's inclusion in an analytic sample. Although excluding participants who fail to meet scope conditions is theoretically consistent, researchers have yet to establish how this practice affects experimental outcomes. I employ meta-analysis to compare studies within the expectation states tradition in which participants are excluded for failure to meet scope conditions to studies in which no similar exclusions are made. Results suggest that studies that exclude participants for scope violations demonstrate a decreased baseline tendency to reject influence. I contend that adopting a more universal approach to the measurement and application of scope conditions would be methodologically and theoretically beneficial to expectation states research.

  18. Analytical magnetic torque calculations and experimental testing of radial flux permanent magnet-type eddy current brakes

    Science.gov (United States)

    Choi, Jang-Young; Jang, Seok-Myeong

    2012-04-01

    This paper reports on analytical magnetic torque calculations and experimental tests of a radial flux permanent magnet (RFPM)-type eddy current brake (ECB). Analytical solutions for permanent magnet-generated magnetic fields that consider the eddy current reaction are obtained by using a magnetic vector potential and a two dimensional (2D) polar coordinate system. On the basis of these solutions, the analytical expressions for a magnetic torque are also derived. All analytical results are validated extensively by non-linear finite element calculations. In particular, magnetic torque measurements are obtained in tests to confirm the analyses. Finally, practical issues related to the analytical study of RFPM-type ECBs are fully discussed.

  19. Current Pressure Transducer Application of Model-based Prognostics Using Steady State Conditions

    Science.gov (United States)

    Teubert, Christopher; Daigle, Matthew J.

    2014-01-01

    Prognostics is the process of predicting a system's future states, health degradation/wear, and remaining useful life (RUL). This information plays an important role in preventing failure, reducing downtime, scheduling maintenance, and improving system utility. Prognostics relies heavily on wear estimation. In some components, the sensors used to estimate wear may not be fast enough to capture brief transient states that are indicative of wear. For this reason it is beneficial to be capable of detecting and estimating the extent of component wear using steady-state measurements. This paper details a method for estimating component wear using steady-state measurements, describes how this is used to predict future states, and presents a case study of a current/pressure (I/P) Transducer. I/P Transducer nominal and off-nominal behaviors are characterized using a physics-based model, and validated against expected and observed component behavior. This model is used to map observed steady-state responses to corresponding fault parameter values in the form of a lookup table. This method was chosen because of its fast, efficient nature, and its ability to be applied to both linear and non-linear systems. Using measurements of the steady state output, and the lookup table, wear is estimated. A regression is used to estimate the wear propagation parameter and characterize the damage progression function, which are used to predict future states and the remaining useful life of the system.

  20. Employment and employment conditions in the current economic crisis in Croatia

    Directory of Open Access Journals (Sweden)

    Goran Vukšić

    2014-06-01

    Full Text Available The goal of this research is to analyze developments in employment and employment characteristics during the current crisis in Croatia. The main findings can be summarized as follows: (1 The primary (aggregate mode of adjustment to the crisis was a decline in employment. There are, however, considerable differences in adjustment patterns across economic activities. (2 During the crisis, jobs were lost in the, more dynamic, private sector, while the number of jobs in the public sector (entities in state ownership slightly increased. (3 Economic activities with comparatively larger shares of women in employment have experienced fewer employment cuts and the aggregate employment share of women rose during the crisis, especially in activities with a larger share of public sector workers.(4 There has been a declining share of younger workers during the crisis, justifying policy actions to facilitate their employment. (5 Employees with comparatively lower educational attainment face severe challenges in the labor market, which is a longer term trend, not specific to the crisis period. There are indications that this group of employees enjoys a higher level of protection in the public sector. (6 Analysis also shows a rising significance of more flexible forms of employment: increasing shares of fixed term employees (during the last two observed years, and of part time workers. (7 Working hours do not exhibit any strong trends specific to the crisis, except for the diminishing number of overtime hours per worker.

  1. They see a rat, we seek a cure for diseases: the current status of animal experimentation in medical practice.

    Science.gov (United States)

    Kehinde, Elijah O

    2013-01-01

    The objective of this review article was to examine current and prospective developments in the scientific use of laboratory animals, and to find out whether or not there are still valid scientific benefits of and justification for animal experimentation. The PubMed and Web of Science databases were searched using the following key words: animal models, basic research, pharmaceutical research, toxicity testing, experimental surgery, surgical simulation, ethics, animal welfare, benign, malignant diseases. Important relevant reviews, original articles and references from 1970 to 2012 were reviewed for data on the use of experimental animals in the study of diseases. The use of laboratory animals in scientific research continues to generate intense public debate. Their use can be justified today in the following areas of research: basic scientific research, use of animals as models for human diseases, pharmaceutical research and development, toxicity testing and teaching of new surgical techniques. This is because there are inherent limitations in the use of alternatives such as in vitro studies, human clinical trials or computer simulation. However, there are problems of transferability of results obtained from animal research to humans. Efforts are on-going to find suitable alternatives to animal experimentation like cell and tissue culture and computer simulation. For the foreseeable future, it would appear that to enable scientists to have a more precise understanding of human disease, including its diagnosis, prognosis and therapeutic intervention, there will still be enough grounds to advocate animal experimentation. However, efforts must continue to minimize or eliminate the need for animal testing in scientific research as soon as possible. © 2013 S. Karger AG, Basel.

  2. A study on the counter current and cocurrent annular flow critical heat flux under low flow conditions

    Energy Technology Data Exchange (ETDEWEB)

    Park, Cheol

    1998-02-15

    Empirical and phenomenological investigations have been performed for countercurrent and cocurrent annular flow critical heat fluxes(CHFs) under low flow conditions. The CHF characteristics on finned surfaces were also examined by experiments and analyses for finned and unfinned geometries. A new form of C{sub w}{sup 2} in the Wallis flooding correlation was proposed for a general use in predicting the flooding limited CHF at tubes, annuli and rectangular channels under zero and very low flow conditions. The suggested correlation showed reasonable predictions compared to the measured CHF with an root-mean-square(RMS) error of 18.8%. A physical model for the prediction of a CHF location at a zero inlet flow condition was improved to take into account entrainment from the liquid film and to extend the applicable range to subcooled inlet flow conditions. The improved model showed reasonable agreements with the Katto data, and provided details of the CHF mechanism due to flooding. It was analytically confirmed that the flooding is a triggering mechanism of a countercurrent annular flow CHF under zero and very low flow conditions. It was also revealed that the heat flux effect such as the nucleation induced entrainment in the liquid film should be considered for the analysis of a flooding limited CHF, especially in small L/D geometry. In addition, an attempt was made to predict CHF values by applying the improved model with predetermined CHF locations. The results showed that the predictions by the improved physical model agreed reasonably with the experimental data. Annular flow hydrodynamic models of Whalley, Levy and Katto, which were developed for high flow conditions, were compared with available low flow CHF data to make out the applicability of the models to low flow conditions. As a result, it was found that Katto model, which improved the fault of Whally and Levy models, could be applied to predict low flow CHF with some improvements although the model

  3. Dy-IP characterization and its application for experimental neutron radiography tests under realistic conditions

    Science.gov (United States)

    Tamaki, Masayoshi; Iida, Kazuhiro; Mori, Noriaki; Lehmann, Eberhard H.; Vontobel, Peter; Estermann, Mirko

    2005-04-01

    Imaging plates containing Dy for neutron radiography have been designed, fabricated and tested experimentally. Using the imaging plates combined with the developed NR system and the honeycomb collimator, quantitative neutron radiograph, which is free from scattered neutron and γ-ray, has been obtained. Application has been conducted for the post-irradiation examination for the nuclear fuel pin.

  4. In vivo screening of extracellular matrix components produced under multiple experimental conditions implanted in one animal.

    NARCIS (Netherlands)

    Higuera Sierra, G.A.; Hendriks, J.A.; Dalum, van J.; Wu, L.; Schotel, R.; Moreira Teixeira, L.S.; Doel, van den M.; Leijten, J.C.H.; Riesle, J.; Karperien, H.B.J.; Blitterswijk, van C.A.; Moroni, L.

    2013-01-01

    Animal experiments help to progress and ensure safety of an increasing number of novel therapies, drug development and chemicals. Unfortunately, these also lead to major ethical concerns, costs and limited experimental capacity. We foresee a coercion of all these issues by implantation of well syste

  5. Experimental data and boundary conditions for a Double - Skin Facade building in transparent insulation mode

    DEFF Research Database (Denmark)

    Larsen, Olena Kalyanova; Heiselberg, Per; Jensen, Rasmus Lund

    was carried out in a full scale test facility ‘The Cube’, in order to compile three sets of high quality experimental data for validation purposes. The data sets are available for preheating mode, external air curtain mode and transparent insulation mode. The objective of this article is to provide the reader...

  6. Experimental-numerical study of heat flow in deep low-enthalpy geothermal conditions

    NARCIS (Netherlands)

    Saeid, S.; Al-Khoury, R.; Nick, H.M.; Barends, F.

    2014-01-01

    This paper presents an intensive experimental-numerical study of heat flow in a saturated porous domain. A temperature and a flow rate range compared to that existing in a typical deep low-enthalpy hydrothermal system is studied. Two main issues are examined: the effect of fluid density and viscosit

  7. Experimental Simulation of the Behaviour of Diagnostic First Mirrors Fabricated of Different Metals for ITER Conditions

    NARCIS (Netherlands)

    Voitsenya, V.; Bardamid, A. F.; Donne, A. J. H.

    2016-01-01

    In the experimental fusion reactor ITER, the plasma-facing component of each optical and/or laser diagnostic needs to be based on reflective optics with at least one mirror (first mirror) facing the thermonuclear plasma. The different kinds of radiation emanating from the burning plasma (neutrons, n

  8. A Bayesian Hierarchical Modeling Scheme for Estimating Erosion Rates Under Current Climate Conditions

    Science.gov (United States)

    Lowman, L.; Barros, A. P.

    2014-12-01

    Computational modeling of surface erosion processes is inherently difficult because of the four-dimensional nature of the problem and the multiple temporal and spatial scales that govern individual mechanisms. Landscapes are modified via surface and fluvial erosion and exhumation, each of which takes place over a range of time scales. Traditional field measurements of erosion/exhumation rates are scale dependent, often valid for a single point-wise location or averaging over large aerial extents and periods with intense and mild erosion. We present a method of remotely estimating erosion rates using a Bayesian hierarchical model based upon the stream power erosion law (SPEL). A Bayesian approach allows for estimating erosion rates using the deterministic relationship given by the SPEL and data on channel slopes and precipitation at the basin and sub-basin scale. The spatial scale associated with this framework is the elevation class, where each class is characterized by distinct morphologic behavior observed through different modes in the distribution of basin outlet elevations. Interestingly, the distributions of first-order outlets are similar in shape and extent to the distribution of precipitation events (i.e. individual storms) over a 14-year period between 1998-2011. We demonstrate an application of the Bayesian hierarchical modeling framework for five basins and one intermontane basin located in the central Andes between 5S and 20S. Using remotely sensed data of current annual precipitation rates from the Tropical Rainfall Measuring Mission (TRMM) and topography from a high resolution (3 arc-seconds) digital elevation map (DEM), our erosion rate estimates are consistent with decadal-scale estimates based on landslide mapping and sediment flux observations and 1-2 orders of magnitude larger than most millennial and million year timescale estimates from thermochronology and cosmogenic nuclides.

  9. Groundwater resources of the Devils Postpile National Monument—Current conditions and future vulnerabilities

    Science.gov (United States)

    Evans, William C.; Bergfeld, Deborah

    2017-06-15

    This study presents an extensive database on groundwater conditions in and around Devils Postpile National Monument. The database contains chemical analyses of springs and the monument water-supply well, including major-ion chemistry, trace element chemistry, and the first information on a list of organic compounds known as emerging contaminants. Diurnal, seasonal, and annual variations in groundwater discharge and chemistry are evaluated from data collected at five main monitoring sites, where streams carry the aggregate flow from entire groups of springs. These springs drain the Mammoth Mountain area and, during the fall months, contribute a significant fraction of the San Joaquin River flow within the monument. The period of this study, from fall 2012 to fall 2015, includes some of the driest years on record, though the seasonal variability observed in 2013 might have been near normal. The spring-fed streams generally flowed at rates well below those observed during a sequence of wet years in the late 1990s. However, persistence of flow and reasonably stable water chemistry through the recent dry years are indicative of a sizeable groundwater system that should provide a reliable resource during similar droughts in the future. Only a few emerging contaminants were detected at trace levels below 1 microgram per liter (μg/L), suggesting that local human visitation is not degrading groundwater quality. No indication of salt from the ski area on the north side of Mammoth Mountain could be found in any of the groundwaters. Chemical data instead show that natural mineral water, such as that discharged from local soda springs, is the main source of anomalous chloride in the monument supply well and in the San Joaquin River. The results of the study are used to develop a set of recommendations for future monitoring to enable detection of deleterious impacts to groundwater quality and quantity

  10. The peculiarities of the ultrastructure of frontal cortex and hippocampus of rats in conditions of experimental allergic encephalomyelitis

    Directory of Open Access Journals (Sweden)

    Nefodov A.A.

    2016-03-01

    Full Text Available Background. Multiple sclerosis refers to the demyelinating diseases of the nervous system, in which the main pathological changes develop in the white matter and are characterized by disintegration of myelin sheaths of conductive systems in different parts of the brain and spinal cord. Objective. To assess the degree of ultrastructural changes of frontal cortex and hippocampus of rats in conditions of experimental allergic encephalomyelitis. Methods. The research was conducted on 14 white rats divided randomly in 2 groups: group 1 – intact animals; group 2 – rats with experimental allergic encephalomyelitis. Experimental allergic encephalomyelitis was induced in 8 animals of the experimental group single subcutaneous inoculation encephalitogenic mixture in full adjuvant of Freynd at the rate of 100 mg homogenate of homologous spinal cord, 0.2 ml puff (the content of killed mycobacteria 5 mg/ml and 0.2 ml of physiological solution on the animal. Transmission electron microscopy was performed on the 14th day of encephalitogenic mixture administration. Results. In the frontal cortex and hippocampus experimental allergic encephalomyelitis induces apoptosis of the neurocytes with disruption of the structure of mitochondria (increase in size, the fragmentation of the outer membrane, destruction of cristae, disseminated perineuronal edema of the brain substance, violation of the structure of most axo-somatic synapses, the demyelination of nerve conductors with signs of fragmentation of neurofibril. Conclusion. The single subcutaneous inoculation of encephalitogenic mixture in full adjuvant of Freynd leads to the development of multifocal demyelination and axonal degeneration in the hippocampus and frontal cortex of experimental animals. Citation: Nefodov AA, Mamchur VI, Tverdokhleb IV. [The peculiarities of the ultrastructure of frontal cortex and hippocampus of rats in conditions of experimental allergic encephalomyelitis]. Morphologia. 2016

  11. The reaction between iodine and organic coatings under severe PWR accident conditions. An experimental parameter study

    Energy Technology Data Exchange (ETDEWEB)

    Hellmann, S.; Funke, F.; Greger, G.U.; Bleier, A.; Morell, W. [Siemens AG, Power Generation Group, Erlangen (Germany)

    1996-12-01

    An extensive experimental parameter study was performed on the deposition and on the resuspension kinetics in the reaction system iodine/organically coated surfaces. Both reactions in the gas phase and in the liquid phase were investigated and kinetic rate constants suitable for modelling were derived. Previous experimental studies on the reaction of iodine with organic coated surfaces were mostly limited to temperatures below 100{sup o}C. Thus, this parameter study aims at filling a gap and providing kinetic data on heterogeneous reactions with organic surfaces in the accident-relevant temperature range of 100-160{sup o}C. Two types of laboratory experiments carried out at Siemens/KWU using coatings representative for German power plants (epoxy-tape paint), namely gas phase tests and liquid phase tests. (author) 6 figs., 6 tabs., 5 refs.

  12. Cytokine investigations in organs and tissues of experimental animals under prenatal hypoxic conditions of varying severity

    Directory of Open Access Journals (Sweden)

    Talgat Kudaibergenov

    2011-04-01

    Full Text Available The paper presents the research results of varying severity experimental hypoxia influences on the content of cytokines (IGF-1, TNF-α, IL-1β, IL-4, IL-6, IFN-γ in organs, tissues and cells (blood, liver, brain, uterus, adrenal glands, placenta, placental lymphocytes and macrophages of pregnant rats. The results showed the increase of pro-inflammatory cytokines synthesis on the local and system levels during experimental hypoxia augmentation. There was found the difference between placental lymphocytes and macrophages secretion. These changes of cytokine profile leads to local deficiency of anti-inflammatory factors and indicate on development of pregnancy complications and “mother-placenta-fetus” system dysfunction.

  13. Methodology to estimate parameters of an excitation system based on experimental conditions

    Energy Technology Data Exchange (ETDEWEB)

    Saavedra-Montes, A.J. [Carrera 80 No 65-223, Bloque M8 oficina 113, Escuela de Mecatronica, Universidad Nacional de Colombia, Medellin (Colombia); Calle 13 No 100-00, Escuela de Ingenieria Electrica y Electronica, Universidad del Valle, Cali, Valle (Colombia); Ramirez-Scarpetta, J.M. [Calle 13 No 100-00, Escuela de Ingenieria Electrica y Electronica, Universidad del Valle, Cali, Valle (Colombia); Malik, O.P. [2500 University Drive N.W., Electrical and Computer Engineering Department, University of Calgary, Calgary, Alberta (Canada)

    2011-01-15

    A methodology to estimate the parameters of a potential-source controlled rectifier excitation system model is presented in this paper. The proposed parameter estimation methodology is based on the characteristics of the excitation system. A comparison of two pseudo random binary signals, two sampling periods for each one, and three estimation algorithms is also presented. Simulation results from an excitation control system model and experimental results from an excitation system of a power laboratory setup are obtained. To apply the proposed methodology, the excitation system parameters are identified at two different levels of the generator saturation curve. The results show that it is possible to estimate the parameters of the standard model of an excitation system, recording two signals and the system operating in closed loop with the generator. The normalized sum of squared error obtained with experimental data is below 10%, and with simulation data is below 5%. (author)

  14. Anodic oxidation of oxytetracycline: Influence of the experimental conditions on the degradation rate and mechanism

    Directory of Open Access Journals (Sweden)

    Annabel Fernandes

    2014-12-01

    Full Text Available The anodic oxidation of oxytetracycline was performed with success using as anode a boron-doped diamond electrode. The experiments were conducted in batch mode, using two different electrochemical cells: an up-flow cell, with recirculation, that was used to evaluate the influence of recirculation flow rate; and a stirred cell, used to determine the influence of the applied current density. Besides oxytetracyclin electrodegradation rate and mineralization extent, oxidation by-products were also assessed. Both the flow rate and the applied current density have shown positive influence on the oxytetracycline oxidation rate. On the other hand, the mineralization degree presented the highest values at the lowest flow rate and the lowest current density tested. The main oxidation by-products detected were oxalic, oxamic and maleic acids.

  15. Experimental Study and Modelling of Char Combustion under Fluidized Bed Conditions

    Institute of Scientific and Technical Information of China (English)

    ZhangYongzhe; ManfredC.Wirsum; 等

    1998-01-01

    The combustion behavior of chars from two Chinese coals has been investigated in a laboratory scale bubbling fludized bed system in Siegen University,Germany,Experimental equipment and method are introduced.The shrinking-core model and the “shrinking-particl” model were employed to evaluate the kinetic parameters.The results indicated that the char conversion process of these two coals can be well described by the two models.

  16. Discovery of wall-selective carbon nanotube growth conditions via automated experimentation.

    Science.gov (United States)

    Nikolaev, Pavel; Hooper, Daylond; Perea-López, Nestor; Terrones, Mauricio; Maruyama, Benji

    2014-10-28

    Applications of carbon nanotubes continue to advance, with substantial progress in nanotube electronics, conductive wires, and transparent conductors to name a few. However, wider application remains impeded by a lack of control over production of nanotubes with the desired purity, perfection, chirality, and number of walls. This is partly due to the fact that growth experiments are time-consuming, taking about 1 day per run, thus making it challenging to adequately explore the many parameters involved in growth. We endeavored to speed up the research process by automating CVD growth experimentation. The adaptive rapid experimentation and in situ spectroscopy CVD system described in this contribution conducts over 100 experiments in a single day, with automated control and in situ Raman characterization. Linear regression modeling was used to map regions of selectivity toward single-wall and multiwall carbon nanotube growth in the complex parameter space of the water-assisted CVD synthesis. This development of the automated rapid serial experimentation is a significant progress toward an autonomous closed-loop learning system: a Robot Scientist.

  17. Determining heavy metals in spent compact fluorescent lamps (CFLs) and their waste management challenges: Some strategies for improving current conditions

    Energy Technology Data Exchange (ETDEWEB)

    Taghipour, Hassan, E-mail: hteir@yahoo.com [Department of Environmental Health Engineering, Tabriz University of Medical Sciences, Tabriz (Iran, Islamic Republic of); Amjad, Zahra [Student Research Committee, Department of Environmental Health Engineering, Tabriz University of Medical Sciences, Tabriz (Iran, Islamic Republic of); Jafarabadi, Mohamad Asghari [Medical Education Research Center, Department of Statistics and Epidemiology, Tabriz University of Medical Sciences, Tabriz (Iran, Islamic Republic of); Gholampour, Akbar [Department of Environmental Health Engineering, Tabriz University of Medical Sciences, Tabriz (Iran, Islamic Republic of); Norouz, Prviz [Environmental Health Engineering, Shahid Beheshti University of Medical Sciences, Tehran (Iran, Islamic Republic of)

    2014-07-15

    Highlights: • Heavy metals in spent compact fluorescent lamps (CFLs) determined. • Current waste management condition of CFLs in Iran assessed. • Currently, waste of CFLs is disposed by municipal waste stream in waste landfills. • We propose extended producer responsibility (EPR) for CFLs waste management. - Abstract: From environmental viewpoint, the most important advantage of compact fluorescent lamps (CFLs) is reduction of green house gas emissions. But their significant disadvantage is disposal of spent lamps because of containing a few milligrams of toxic metals, especially mercury and lead. For a successful implementation of any waste management plan, availability of sufficient and accurate information on quantities and compositions of the generated waste and current management conditions is a fundamental prerequisite. In this study, CFLs were selected among 20 different brands in Iran. Content of heavy metals including mercury, lead, nickel, arsenic and chromium was determined by inductive coupled plasma (ICP). Two cities, Tehran and Tabriz, were selected for assessing the current waste management condition of CFLs. The study found that waste generation amount of CFLs in the country was about 159.80, 183.82 and 153.75 million per year in 2010, 2011 and 2012, respectively. Waste generation rate of CFLs in Iran was determined to be 2.05 per person in 2012. The average amount of mercury, lead, nickel, arsenic and chromium was 0.417, 2.33, 0.064, 0.056 and 0.012 mg per lamp, respectively. Currently, waste of CFLs is disposed by municipal waste stream in waste landfills. For improving the current conditions, we propose by considering the successful experience of extended producer responsibility (EPR) in other electronic waste management. The EPR program with advanced recycling fee (ARF) is implemented for collecting and then recycling CFLs. For encouraging consumers to take the spent CFLs back at the end of the products’ useful life, a proportion of

  18. Experimental simulation of asymmetric heat up of coolant channel under small break LOCA condition for PHWR

    Energy Technology Data Exchange (ETDEWEB)

    Yadav, Ashwini K., E-mail: ashwinikumaryadav@gmail.com [Department of Mechanical and Industrial Engineering, Indian Institute of Technology, Roorkee 247667 (India); Majumdar, P., E-mail: pmajum@barc.gov.in [Reactor Safety Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Kumar, Ravi, E-mail: ravikfme@iitr.ernet.in [Department of Mechanical and Industrial Engineering, Indian Institute of Technology, Roorkee 247667 (India); Chatterjee, B., E-mail: barun@barc.gov.in [Reactor Safety Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Gupta, Akhilesh, E-mail: akhilfme@iitr.ernet.in [Department of Mechanical and Industrial Engineering, Indian Institute of Technology, Roorkee 247667 (India); Mukhopadhyay, D., E-mail: dmukho@barc.gov.in [Reactor Safety Division, Bhabha Atomic Research Centre, Mumbai 400085 (India)

    2013-02-15

    Highlights: ► Circumferential temperature gradient of PT for asymmetric heat-up was 440 °C. ► At 2 MPa ballooning initiated at 450 °C and with strain rate of 0.0277%/s. ► At 4 MPa ballooning initiated at 390 °C and with strain rate of 0.0305%/s. ► At 4 MPa, PT ruptured under uneven strain and steep temperature gradient. ► Integrity of PT depends on internal pressure and magnitude of decay power. -- Abstract: During postulated small break loss of coolant accident (SBLOCA) for Pressurised Heavy Water Reactors (PHWRs) as well as for postulated SBLOCA coincident with loss of ECCS, a stratified flow condition can arise in the coolant channels as the gravitational force dominates over the low inertial flow arising from small break flow. A Station Blackout condition without operator intervention can also lead to stratified flow condition during a slow channel boil-off condition. For all these conditions the pressure remains high and under stratified flow condition, the horizontal fuel bundles experience different heat transfer environments with respect to the stratified flow level. This causes the bundle upper portion to get heated up higher as compared to the submerged portion. This kind of asymmetrical heating of the bundle is having a direct bearing on the circumferential temperature gradient of pressure tube (PT) component of the coolant channel. The integrity of the PT is important under normal conditions as well as at different accident loading conditions as this component houses the fuel bundles and serves as a coolant pressure boundary of the reactors. An assessment of PT is required with respect to different accident loading conditions. The present investigation aims to study thermo-mechanical behaviour of PT (Zr, 2.5 wt% Nb) under a stratified flow condition under different internal pressures. The component is subjected to an asymmetrical heat-up conditions as expected during the said situation under different pressure conditions which varies from 2

  19. Experimental study of a finned-tubes coil with wet wall conditions; Etude experimentale d'une batterie froide en condition de paroi mouillee

    Energy Technology Data Exchange (ETDEWEB)

    Khalfi, M.S. [Institut Algerien du Petrole, Boumerdes (Algeria); Benelmir, R.; Feidt, M. [Universite Henri Poincare, Lab. d' Energetique et de Mecanique Theorique et Appliquee, 54 - Vandoeuvre-les-Nancy (France)

    2001-01-01

    The use of a global pseudo-conductance in the mathematical model of heat and mass transfer within a heat exchanger allowed us to take into account the water condensate on the wall as well as air humidity. The application of this dual consideration to our experimental investigation shows a 'critical' Reynolds number at which we observe an inversion of thermal behavior. The heat exchanger considered in this work has been used in a previous published work where heat transfer occurred only with dry wall condition. (authors)

  20. Experimental study of the pressure fluctuations on propeller turbine runner blades: part 2, transient conditions

    Science.gov (United States)

    Houde, S.; Fraser, R.; Ciocan, G.; Deschênes, C.

    2012-11-01

    Transient conditions such as load rejection will often lead to high amplitude pressure fluctuations that will affect a turbine residual-life. If Computational Fluid Dynamic offers a promising tool to study the flow dynamic under transient regime, focused validation data on the runner are still lacking to assess the accuracy of different simulation strategies. Hence within the framework of the AxialT project of the International Consortium on Hydraulic Machines, exploratory measurements of the pressure field on the runner blades of a propeller turbine model were performed in transient conditions. The model was setup on the test stand of the LAMH of Laval University. The test stand control procedures were adapted to mimic transient condition such as load rejection or the transition from a normal operating condition to a speed-no-load condition. The pressure on the runner blades were measured using miniature piezo-resistive transducer linked to a high frequency telemetric system. Using specifically adapted data processing routines, it was possible to characterize the variations of the energy content during the transient runs. Specifically, the main fluctuations appear to occur in the sub-synchronous range in both cases.