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Sample records for professor experimental condensed

  1. Experimental Investigation of Flow Condensation in Microgravity

    Science.gov (United States)

    Lee, Hyoungsoon; Park, Ilchung; Konishi, Christopher; Mudawar, Issam; May, Rochelle I.; Juergens, Jeffery R.; Wagner, James D.; Hall, Nancy R.; Nahra, Henry K.; Hasan, Mohammed M.; hide

    2013-01-01

    Future manned missions to Mars are expected to greatly increase the space vehicle's size, weight, and heat dissipation requirements. An effective means to reducing both size and weight is to replace single-phase thermal management systems with two-phase counterparts that capitalize upon both latent and sensible heat of the coolant rather than sensible heat alone. This shift is expected to yield orders of magnitude enhancements in flow boiling and condensation heat transfer coefficients. A major challenge to this shift is a lack of reliable tools for accurate prediction of two-phase pressure drop and heat transfer coefficient in reduced gravity. Developing such tools will require a sophisticated experimental facility to enable investigators to perform both flow boiling and condensation experiments in microgravity in pursuit of reliable databases. This study will discuss the development of the Flow Boiling and Condensation Experiment (FBCE) for the International Space Station (ISS), which was initiated in 2012 in collaboration between Purdue University and NASA Glenn Research Center. This facility was recently tested in parabolic flight to acquire condensation data for FC-72 in microgravity, aided by high-speed video analysis of interfacial structure of the condensation film. The condensation is achieved by rejecting heat to a counter flow of water, and experiments were performed at different mass velocities of FC-72 and water and different FC-72 inlet qualities. It is shown that the film flow varies from smooth-laminar to wavy-laminar and ultimately turbulent with increasing FC-72 mass velocity. The heat transfer coefficient is highest near the inlet of the condensation tube, where the film is thinnest, and decreases monotonically along the tube, except for high FC-72 mass velocities, where the heat transfer coefficient is enhanced downstream. This enhancement is attributed to both turbulence and increased interfacial waviness. One-ge correlations are shown to

  2. Experimental and theoretical study of reflux condensation

    Energy Technology Data Exchange (ETDEWEB)

    Bakke, Knut

    1997-12-31

    This thesis studies the separation of gas mixtures in a reflux condenser. also called a dephlegmator. Reflux condensation is separation of a gas mixture, in reflux flow with condensing liquid, under continuous heat removal. A numerical model of a dephlegmator for binary mixtures was developed. The model may readily be extended to multi-component mixtures, as the solution method is based on a matrix solver. Separation of a binary mixture in a reflux condenser test rig is demonstrated. The test facility contains a single-tube test section that was designed and built as part of the project. Test mixtures of propane and n-butane were used, and a total of 15 experiments are reported. Limited degree of separation was achieved due to limited heat transfer area and narrow boiling point range of the test mixture. The numerical model reproduces the experimental data within reasonable accuracy. Deviation between calculated and measured properties is less than 6% of the measured temperature and less than 5% of the measured flow rate. The model is based on mechanistic models of physical processes and is not calibrated or tuned to fit the experimental data. The numerical model is applied to a number of separation processes. These case studies show that the required heat transfer area increases rapidly with increments in top product composition (light component). Flooding limits the amount of reflux liquid. The dephlegmator is suitable for separation of feed mixtures that are rich in light components. The gliding temperature in the dephlegmation process enables utilization of top product as refrigerant, with subsequent energy saving as a result. 61 refs., 50 figs., 34 tabs.

  3. Experimental Effects of Student Evaluations Coupled with Collaborative Consultation on College Professors' Instructional Skills

    NARCIS (Netherlands)

    Knol, M.H.; in 't Veld, R.; Vorst, H.C.M.; van Driel, J.H.; Mellenbergh, G.J.

    2013-01-01

    This experimental study concerned the effects of repeated students’ evaluations of teaching coupled with collaborative consultation on professors’ instructional skills. Twenty-five psychology professors from a Dutch university were randomly assigned to either a control group or an experimental

  4. Experimental and numerical study on condensation in transonic steam flow

    Directory of Open Access Journals (Sweden)

    Majkut Mirosław

    2015-09-01

    Full Text Available The present paper describes an experimental and numerical study of steam condensing flow in a linear cascade of turbine stator blades. The experimental research was performed on the facility of a small scale steam power plant located at Silesian University of Technology in Gliwice, Poland. The test rig of the facility allows us to perform the tests of steam transonic flows for the conditions corresponding to these which prevail in the low-pressure (LP condensing steam turbine stages. The experimental data of steam condensing flow through the blade-to- blade stator channel were compared with numerical results obtained using the in-house CFD numerical code TraCoFlow. Obtained results confirmed a good quality of the performed experiment and numerical calculations.

  5. Integral Reactor Containment Condensation Model and Experimental Validation

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Qiao [Oregon State Univ., Corvallis, OR (United States); Corradini, Michael [Univ. of Wisconsin, Madison, WI (United States)

    2016-05-02

    This NEUP funded project, NEUP 12-3630, is for experimental, numerical and analytical studies on high-pressure steam condensation phenomena in a steel containment vessel connected to a water cooling tank, carried out at Oregon State University (OrSU) and the University of Wisconsin at Madison (UW-Madison). In the three years of investigation duration, following the original proposal, the planned tasks have been completed: (1) Performed a scaling study for the full pressure test facility applicable to the reference design for the condensation heat transfer process during design basis accidents (DBAs), modified the existing test facility to route the steady-state secondary steam flow into the high pressure containment for controllable condensation tests, and extended the operations at negative gage pressure conditions (OrSU). (2) Conducted a series of DBA and quasi-steady experiments using the full pressure test facility to provide a reliable high pressure condensation database (OrSU). (3) Analyzed experimental data and evaluated condensation model for the experimental conditions, and predicted the prototypic containment performance under accidental conditions (UW-Madison). A film flow model was developed for the scaling analysis, and the results suggest that the 1/3 scaled test facility covers large portion of laminar film flow, leading to a lower average heat transfer coefficient comparing to the prototypic value. Although it is conservative in reactor safety analysis, the significant reduction of heat transfer coefficient (50%) could under estimate the prototypic condensation heat transfer rate, resulting in inaccurate prediction of the decay heat removal capability. Further investigation is thus needed to quantify the scaling distortion for safety analysis code validation. Experimental investigations were performed in the existing MASLWR test facility at OrST with minor modifications. A total of 13 containment condensation tests were conducted for pressure

  6. Experimental and Thermalhydraulic Code Assessment of the Transient Behavior of the Passive Condenser System in an Advanced Boiling Water Reactor

    Energy Technology Data Exchange (ETDEWEB)

    S.T. Revankar; W. Zhou; Gavin Henderson

    2008-07-08

    The main goal of the project was to study analytically and experimentally the condensation heat transfer for the passive condenser system such as GE Economic Simplified Boiling Water Reactor (ESBWR). The effect of noncondensable gas in condenser tube and the reduction of secondary pool water level to the condensation heat transfer coefficient was the main focus in this research. The objectives of this research were to : 1) obtain experimental data on the local and tube averaged condensation heat transfer rates for the PCCS with non-condensable and with change in the secondary pool water, 2) assess the RELAP5 and TRACE computer code against the experimental data, and 3) develop mathematical model and ehat transfer correlation for the condensation phenomena for system code application. The project involves experimentation, theoretical model development and verification, and thermal- hydraulic codes assessment.

  7. Experimental determination of loss and changes in condensate production during complete depletion of PK formations in Karadag Field

    Energy Technology Data Exchange (ETDEWEB)

    Razamat, M.S.; Dzhavadov, A.A.; Ramazanova, Z.E.

    1968-01-01

    Since 1964, gas condensate has been produced from the PK formations of Karadag field without pressure maintenance. Under such conditions, condensate is left in the formation by retrograde condensation. The loss of condensate was determined experimentally by running differential condensations on liquids from 2 wells in the field. It was found that as reservoir pressure decreases, condensate loss increases until pressures of 60-70 atm are reached, after which condensate loss diminished slightly as light hydrocarbons enter the gas phase. When reservoir pressure reaches 1 atm, condensate loss reaches about 1.7% by vol, and 4.7% by wt. Good agreement was found between data from differential condensation runs and analytical data on produced fluid composition.

  8. Experimental analysis of ammonia condensation on smooth and integral-fin titanium tubes

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez-Seara, Jose; Uhia, Francisco J.; Diz, Ruben [Area de Maquinas y Motores Termicos, E.T.S. de Ingenieros Industriales, University of Vigo, Campus Lagoas-Marcosende No 9, 36310 Vigo (Spain)

    2009-09-15

    This paper reports on the experimental research conducted to study the condensation of ammonia on smooth and integral-fin (32 fpi) titanium tubes of 19.05 mm outer diameter. Experiments were carried out at saturation temperatures of 30, 35, 40 and 45 C and wall subcoolings from 1 to 8 C. The results show that the condensation coefficients on the smooth tubes are well predicted by the Nusselt theory with an average error of +0.66% and within a deviation between -6.6% and +8.3%. The enhancement factors provided by the integral-fin tubes range from 0.77 to 1.22. The low enhancement factors are due to the high condensate retention between fins, which brings about flooded fractions of the tube perimeter from 62.9% to 73.2%, and the low thermal conductivity of titanium. The Briggs and Rose [1994. Effect of fin efficiency on a model for condensation heat transfer on a horizontal, integral-fin tube. Int. J. Heat Mass Transfer 37, 457-463.] model, which accounts for the conduction in the fins, predicts the experimental data with a mean overestimation of 20%. The analysis of the partial thermal resistances in the overall heat transfer process points out the convenience of enhancing the outside ammonia condensation when high water velocities are considered inside the tubes. (author)

  9. Experimental study of undeveloped nucleate boiling on the horizontal tube heated by condensing steam

    Energy Technology Data Exchange (ETDEWEB)

    Morozov, A.V.; Remizov, O.V.; Tzyganok, A.A.; Kalyakin, D.S. [State Scientific Center of the Russian Federation, Inst. for Physics and Power Engineering named after A.I. Leypunsky, Obninsk (Russian Federation)

    2011-07-01

    The experimental study of undeveloped nucleate boiling on the horizontal tube heated by condensing steam has been carried out in the Institute for Physics and Power Engineering. The feature of the processes investigated was a presence of natural circulation in primary circuit of the facility. The experiments were carried out at heating steam pressure P{sub s1} = 0.35 MPa. On the base of the results of these experiments the empirical correlations for prediction of heat transfer coefficient was obtained. This correlation can be used for the substantiation of work of VVER steam generator in the condensation mode. (author)

  10. Experimental determination of critical parameters for gas-condensate-oil systems

    Energy Technology Data Exchange (ETDEWEB)

    Ramazanova, Z.E.; Yagubov, A.S.; Razamat, M.S.; Babaev, R.D.

    1971-01-01

    An experimental study was conducted to determine the effect of crude oil quantity and quality on changes of critical parameters in gas-condensate-oil systems. Experiments were performed at 40/sup 0/, 100/sup 0/, and 140/sup 0/C, and pressures up to 1,000 kg/sq cm. The 3 components of the system were gas, condensate, and crude oil. Isotherms of condensation were determined to the left and right of the critical point, reaching one-phase zones for liquid and gas. Experimental values of critical parameters varied widely from calculated values. Even insignificant changes in composition caused sharp changes in the critical parameters. For example by changing the weight fraction of crude oil from 0.499 to 0.503, critical temperature changed from 40/sup 0/ to 140/sup 0/C and critical pressure from 640 to 780 kg/sq cm. This type of occurrence must be kept in mind when exploiting gas-oil reservoirs near the critical range.

  11. The Measurement of Electron-Induced Erosion of Condensed Gases: Experimental Methods

    DEFF Research Database (Denmark)

    Schou, Jørgen; Sørensen, H.; Børgesen, P.

    1984-01-01

    Two experimental methods for measuring the erosion yield of condensed gases are described. One, the frequency-change method, utilizes a quartz-crystal microbalance operating at liquid-helium temperature. The other, the emissivity-change method is based on the strongly varying electron emission...... as a function of the condensed-gas film thickness. Satisfactory results have been obtained for both methods for solid Ne and D2 at electron energies up to 3 keV, and the mutual agreement is good as well. Accurate measurements are affected critically by the beam conditions, particularly if the erosion yield...... depends on the film thickness. The erosion yield has been measured for dominant electron sputtering of solid Ne ( ≈ 28 Ne-atoms/electron) as well as for beam-induced evaporation at 2 keV. In the latter case a clear lateral broadening of the erosion spot is observed....

  12. Experimental and numerical investigations on the direct contact condensation phenomenon in horizontal flow channels and its implications in nuclear safety

    Energy Technology Data Exchange (ETDEWEB)

    Ceuca, Sabin Cristian [Gesellschaft fuer Anlagen- und Reaktorsicherheit (GRS) gGmbH, Garching (Germany); Laurinavicius, Darius [Lithuanian Energy Institute, Kaunas (Lithuania)

    2016-11-15

    The complex direct contact condensation phenomenon is investigated in horizontal flow channels both experimentally and numerically with special emphasis on its implications on safety assessment studies. Under certain conditions direct contact condensation can act as the driving force for the water hammer phenomenon with potentially local devastating results, thus posing a threat to the integrity of the affected NPP components. New experimental results of in-depth analysis of the direct contact condensation phenomena obtained in Kaunas at the Lithuanian Energy Institute will be presented. The German system code ATHLET employing for the calculation of the heat transfer coefficient a mechanistic model accounting for two different eddy length scales, combined with the interfacial area transport equation will be assessed against condensation induced water hammer experimental data from the integral thermal-hydraulic experimental facility PMK-2, located at the KFKI Atomic Energy Research Institute in Budapest Hungary.

  13. Experimental Investigation of Sulfuric Acid Condensation and Corrosion Rate in Motored Bukh DV24 Diesel Engine

    DEFF Research Database (Denmark)

    Kjemtrup, Lars; Cordtz, Rasmus Faurskov; Meyer, Martin

    2017-01-01

    The work conducted in this paper presents a novel experimental setup to study sulfuric acid cold corrosion of cylinder liners in large two-stroke marine diesel engines. The process is simulated in a motored light duty BUKH DV24 diesel engine where the charge air contain known amounts of H2SO4 and H......2O vapor. Liner corrosion is measured as iron accumulation in the lubeoil. Similarly sulfuric acid condensation is assessed by measuring the accumulation of sulfur in the lube oil. To clarify the corrosive effect of sulfuric acid the lube oil utilized for experiments is a sulfur free neutral oil...

  14. An experimental investigation of the interfacial condensation heat transfer in steam/water countercurrent stratified flow in a horizontal pipe

    Energy Technology Data Exchange (ETDEWEB)

    Chu, In Cheol; Yu, Seon Oh; Chun, Moon Hyun [Korea Advanced Institute of Science and Technology, Taejon (Korea, Republic of); Kim, Byong Sup; Kim, Yang Seok; Kim, In Hwan; Lee, Sang Won [Korea Electric Power Research Institute, Taejon (Korea, Republic of)

    1998-12-31

    An interfacial condensation heat transfer phenomenon in a steam/water countercurrent stratified flow in a nearly horizontal pipe has been experimentally investigated. The present study has been focused on the measurement of the temperature and velocity distributions within the water layer. In particular, the water layer thickness used in the present work is large enough so that the turbulent mixing is limited and the thermal stratification is established. As a result, the thermal resistance of the water layer to the condensation heat transfer is increased significantly. An empirical correlation of the interfacial condensation heat transfer has been developed. The present correlation agrees with the data within {+-} 15%. 5 refs., 6 figs. (Author)

  15. Experimental Investigation of Sulfuric Acid Condensation and Corrosion Rate in Motored Bukh DV24 Diesel Engine

    DEFF Research Database (Denmark)

    Kjemtrup, Lars; Cordtz, Rasmus Faurskov; Meyer, Martin

    2017-01-01

    The work conducted in this paper presents a novel experimental setup to study sulfuric acid cold corrosion of cylinder liners in large two-stroke marine diesel engines. The process is simulated in a motored light duty BUKH DV24 diesel engine where the charge air contain known amounts of H2SO4 and H......2O vapor. Liner corrosion is measured as iron accumulation in the lubeoil. Similarly sulfuric acid condensation is assessed by measuring the accumulation of sulfur in the lube oil. To clarify the corrosive effect of sulfuric acid the lube oil utilized for experiments is a sulfur free neutral oil...... without alkaline additives (Chevron Neutral Oil 600R). Iron and sulfur accumulation in the lube oil is analyzed withan Energy Dispersive X-Ray Fluorescence (ED-XRF) apparatus. Three test cases with different H2SO4 concentrations are run. Results reveal good agreement between sulfuric acid injection flow...

  16. Experimental determination of the heat transfer coefficient in shell-and-tube condensers using the Wilson plot method

    Science.gov (United States)

    Havlik, Jan; Dlouhy, Tomas

    This article deals with the experimental determination of heat transfer coefficients. The calculation of heat transfer coefficients constitutes a crucial issue in design and sizing of heat exchangers. The Wilson plot method and its modifications based on measured experimental data utilization provide an appropriate tool for the analysis of convection heat transfer processes and the determination of convection coefficients in complex cases. A modification of the Wilson plot method for shell-and-tube condensers is proposed. The original Wilson plot method considers a constant value of thermal resistance on the condensation side. The heat transfer coefficient on the cooling side is determined based on the change in thermal resistance for different conditions (fluid velocity and temperature). The modification is based on the validation of the Nusselt theory for calculating the heat transfer coefficient on the condensation side. A change of thermal resistance on the condensation side is expected and the value is part of the calculation. It is possible to improve the determination accuracy of the criterion equation for calculation of the heat transfer coefficient using the proposed modification. The criterion equation proposed by this modification for the tested shell-and-tube condenser achieves good agreement with the experimental results and also with commonly used theoretical methods.

  17. Experimental Investigation and Flow Process Computer Simulation of the Single Mini Channel Condenser for Vapor Compression Refrigeration System

    Science.gov (United States)

    Pabilona, L. L.; Villanueva, E. P.

    2015-09-01

    This study is a computer simulation of the temperature profiles and experimental investigation of three 100 mm x 50 mm x 18 mm single mini channel condensers with hydraulic diameters of 3 mm, 2 mm, and 1mm. The mini channels which were made of copper were designed, fabricated and tested. Each unit was connected in a vapor compression cycle with R-134a as the refrigerant. The average refrigerant mass flow rates were varied from 1.296 - 69.471 g/s, and the average inlet and outlet condenser pressure variations were 102.5 - 121.8 kPa and 101.74 -121.23 kPa, respectively. Each condenser was placed inside a mini wind tunnel system where forced draft air was introduced to initiate convective heat transfer. Each condenser was tested and data were gathered every five minute interval for one hour using a Lab View Software. Computer simulations on the flow process were conducted using Solid Works software. The experimental results presented the inlet and outlet condenser pressures, and pressure drops. The experimental heat transfer coefficients were calculated at different mass fluxes during condensation. The values ranged from 3900 to 5200 W/m2-°K for the 3 mm, 2600 to 9000 W/m2-°K for the 2 mm, and 13 to 98 W/m2-°K for the 1 mm. The heat transfer coefficients calculated from experiments were then compared with the computed values using the correlations developed by Dittus-Boelter and Lee-Son. The results showed increasing deviation as the diameter decreased. The discrepancies could be attributed to the appropriateness of the Dittus-Boelter and Lee-Son correlations in small diameter channels, complexities in the flow process which involved two phase flow heat transfer in very small tubes, and the difficulties in attaining very accurate measurements in small channels.

  18. The modelling of condensation in horizontal tubes and the comparison with experimental data

    Directory of Open Access Journals (Sweden)

    Bryk Rafał

    2017-01-01

    Full Text Available The condensation in horizontal tubes plays an important role in determining the operation mode of passive safety systems of modern nuclear power plants. In this paper, two different approaches for modelling of this phenomenon are compared and verified against experimental data. The first approach is based on the flow regime map developed by Tandon. Depending on the regime, the heat transfer coefficient is calculated according to corresponding semi-empirical correlation. The second approach uses a general, fully empirical correlation proposed by Shah. Both models are developed with utilization of the object-oriented, equation-based Modelica language and the open-source Open-Modelica environment. The results are compared with data obtained during a large scale integral test, simulating a Loss of Coolant Accident scenario performed at the dedicated Integral Test Facility Karlstein (INKA which was built at the Components Testing Department of AREVA in Karlstein, Germany. The INKA facility was designed to test the performance of the passive safety systems of KERENA, the new AREVA boiling water reactor design. INKA represents the KERENA containment with a volume scaling of 1:24. Components heights and levels over the ground are in the full scale. The comparison of simulations results shows a good agreement.

  19. An Experimental Study on Condensation of R744 in a Multi-Port Extruded Tube

    Science.gov (United States)

    Jige, Daisuke; Koyama, Shigeru

    In the present study, the condensation process of R 744 in a horizontal multi-port extruded tube was investigated experimentally. The test tube is made of aluminum alloy, and has 22 rectangular channels of 0.36 mm in hydraulic diameter. Experiments were carried out in the mass velocity range of 470 to 950 kg m-2 s-1 at 5, 6 and 7 MPa in pressure, respectively. The pressure drop characteristics were measured at the both ends of the test section of approximately 730 mm in length. The sectional heat transfer characteristics were also measured in eight subsections of 75 mm in effective heat transfer length using heat flux sensors. As the mass velocity increases and the refrigerant pressure level decreases, the measured pressure drop increases. These data were compared with several previous correlations. The measured heat transfer coefficient decreases as the liquid quality increases, while it increases with increase of mass velocity. These data were compared with several correlations. The high quality data agree relatively with correlations of Moser et al. and Cavallini et al., while those of low quality do not agree with any correlations well. New heat transfer correlation considering effects of vapor shear stress and surface tension is developed.

  20. Condensed argon isentropic compression with ultrahigh magnetic field pressure: Experimental design. Post-shot report

    Energy Technology Data Exchange (ETDEWEB)

    Bykov, A.I.; Boriskov, G.V.; Dolotenko, M.I. [All-Russian Research Inst. of Experimental Physics, Sarov (Russian Federation)] [and others

    1996-12-31

    This report continues the series of work devoted to experimental study of a high-dense condensed argon state. Remember that according to work of Kwon et. al., hexagonal close-packed structure is profitable in terms of energy rather than face-centered argon structure (stable with zero pressure). What is most interesting and intriguing here is the issue of possible argon metallization, when it is compressed up to the densities more than 9.17 g/cm{sup 3}. In the experiment of 1995 (the arrangement and data are described in a cited reference) the authors recorded appearance of conductivity in argon, which is non-conductive in the initial state, when it is compressed more than a factor of four. The peak value of argon specific conductivity recorded in this experiment did not exceed 10 (Ohm x cm){sup {minus}1}. This value of conductivity is characteristic of semiconductors, but not metals, which have 10{sup 4} (Ohm x cm){sup {minus}1}. At this stage of the work the main attention is paid to recording of argon conductive state and studying the possibilities of multiframed radiography of the sample in the compressed state.

  1. A Preliminary Experimental Study of Filmwise and Dropwise Condensation on SUS316 Surface

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Jae Young; Jeong, Yong Hoon [KAIST, Daejeon (Korea, Republic of); Noriyuki, Watanabe [Tokyo Institute of Technology, Tokyo (Japan)

    2015-10-15

    This paper studied about the cooling characteristic of SUS316 surface as a PCCS heat exchanger. Specifically, filmwise and dropwise condensations on SUS316 surface were compared. The passive safety features against station blackout (SBO) and containment safety became important issue after Fukushima accident. As a result, passive containment cooling system (PCCS) is selected as candidate option for the advanced light water reactors to guarantee integrity of containment. To design efficient heat exchanger of PCCS inside of concrete containment, a number of attempts were studied to compensate the low heat transfer coefficient of condensation in non-condensable gas circumstance. The study in this paper focused on the dropwise condensation to enhance the cooling performance of PCCS heat exchanger. Bare SUS316 surface represented stable dropwise condensation phase over 12 hours of experiment for all experiment condition shown in Table I. Figure 3 shows the previous studies conducted by other researcher with our result. Subcooled temperature versus heat transfer coefficient (HTC) of DWC on various cooling surface with coatings were compared. Figure 4 and 5 shows the condensation HTC of DWC and FWC with different non-condensable gas fractions. The result of DWC with pure steam was well proportional to the power of subcooled temperature. Otherwise, the result with non-condensable gas shows HTC in low subcooled temperature under 5 .deg. C seems to be decreased, but the result was shaded by the high uncertainty. The result of FWC also proportional to power of subcooled temperature regardless of air concentration and well separated by air concentration condition.

  2. Fabrication of SiGe-on-insulator substrates by a condensation technique: an experimental and modelling study

    Science.gov (United States)

    Vincent, B.; Damlencourt, J.-F.; Rivallin, P.; Nolot, E.; Licitra, C.; Morand, Y.; Clavelier, L.

    2007-03-01

    Today, to our knowledge, only two techniques are used to perform GeOI substrates: the Smart-Cut™ technique and the Ge condensation technique. The latter is very sensitive to the initial parameters but is the only one which allows Si and Ge-on-insulator co-integration. Predictions of experimental results are then necessary to associate the best processes with the defined starting structures. This paper presents for the first time studies on Ge condensation technique simulations. Enrichment kinetics occurring in the classical one-dimensional condensation process have been simulated by the TCAD Silvaco Athena tool and analytical calculations. The good correlation with experimental data permits us to confirm the process dependence to the initial parameters. The influence of the process-induced non-homogeneities for the prestructure fabrication is also highlighted by the simulation results. The analytical model is efficient to predict a lot of experimental data with short calculation times. For more complex processes involving a two- or three-dimensional oxidation, enrichment prediction accuracy obtained by the analytic model is limited. Mechanism predictions under these experimental conditions are necessary to be studied by TCAD simulations.

  3. Experimental investigation of certain internal condensing and boiling flows: Their sensitivity to pressure fluctuations and heat transfer enhancements

    Science.gov (United States)

    Kivisalu, Michael Toomas

    Space-based (satellite, scientific probe, space station, etc.) and millimeter -- to -- micro-scale (such as are used in high power electronics cooling, weapons cooling in aircraft, etc.) condensers and boilers are shear/pressure driven. They are of increasing interest to system engineers for thermal management because flow boilers and flow condensers offer both high fluid flow-rate-specific heat transfer capacity and very low thermal resistance between the fluid and the heat exchange surface, so large amounts of heat may be removed using reasonably-sized devices without the need for excessive temperature differences. However, flow stability issues and degredation of performance of shear/pressure driven condensers and boilers due to non-desireable flow morphology over large portions of their lengths have mostly prevented their use in these applications. This research is part of an ongoing investigation seeking to close the gap between science and engineering by analyzing two key innovations which could help address these problems. First, it is recommended that the condenser and boiler be operated in an innovative flow configuration which provides a non-participating core vapor stream to stabilize the annular flow regime throughout the device length, accomplished in an energy-efficient manner by means of ducted vapor re-circulation. This is demonstrated experimentally.. Second, suitable pulsations applied to the vapor entering the condenser or boiler (from the re-circulating vapor stream) greatly reduce the thermal resistance of the already effective annular flow regime. For experiments reported here, application of pulsations increased time-averaged heat-flux up to 900 % at a location within the flow condenser and up to 200 % at a location within the flow boiler, measured at the heat-exchange surface. Traditional fully condensing flows, reported here for comparison purposes, show similar heat-flux enhancements due to imposed pulsations over a range of frequencies

  4. Dr Robert Aymar, Director of the International Thermonuclear Experimental Reactor (ITER), was nominated to succeed Professor Luciano Maiani as CERN's Director General, to take office on 1 January 2004.

    CERN Document Server

    2002-01-01

    Dr Robert Aymar, Director of the International Thermonuclear Experimental Reactor (ITER), was nominated to succeed Professor Luciano Maiani as CERN's Director General, to take office on 1 January 2004.

  5. Experimental investigation and CFD analysis of a air cooled condenser heat pipe

    Directory of Open Access Journals (Sweden)

    Annamalai Selvan Arul

    2011-01-01

    Full Text Available In the present work a heat pipe of one meter length and 0.031m outer diameter was constructed and the experiments are conducted to determine the surface and vapour temperature at steady and transient conditions for two different input power in the evaporator section and cooling the condenser section by air. A CFD analysis was also carried and the results under steady state conditions are compared with the results obtained from the experiments and reported in this paper.

  6. Experimental Observation of Modulation Instability and Optical Spatial Soliton Arrays in Soft Condensed Matter

    OpenAIRE

    Reece, P. J.; Wright, E. M.; Dholakia, K.

    2007-01-01

    In this Letter we report observations of optically induced self-organization of colloidal arrays in the presence of un-patterned counter-propagating evanescent waves. The colloidal arrays formed along the laser propagation-axis are shown to be linked to the break-up of the incident field into optical spatial solitons, the lateral spacing of the arrays being related to modulation instability of the soft condensed matter system.

  7. Experimental observation of modulation instability and optical spatial soliton arrays in soft condensed matter.

    Science.gov (United States)

    Reece, P J; Wright, E M; Dholakia, K

    2007-05-18

    In this Letter we report observations of optically induced self-organization of colloidal arrays in the presence of unpatterned counterpropagating evanescent waves. The colloidal arrays formed along the laser propagation axis are shown to be linked to the breakup of the incident field into optical spatial solitons, the lateral spacing of the arrays being related to modulation instability of the soft condensed matter system.

  8. Experimental study of Iranian heavy crude oil viscosity reduction by diluting with heptane, methanol, toluene, gas condensate and naphtha

    Directory of Open Access Journals (Sweden)

    Amir Hossein Saeedi Dehaghani

    2016-12-01

    Full Text Available Due to the high viscosity of heavy crude oils, production from these reservoirs is a demanding task. To tackle this problem, reducing oil viscosity is a promising approach. There are various methods to reduce viscosity of heavy oil: heating, diluting, emulsification, and core annular flow. In this study, dilution approach was employed, using industrial solvents and gas condensate. The viscosity of two Iranian heavy crude oils was measured by mixing with solvents at different temperatures. Dilution of both oil samples with toluene and heptane, resulted in viscosity reduction. However, their effect became less significant at higher concentrations of diluent. Because of forming hydrogen bonds, adding methanol to heavy crude oil resulted in higher viscosity. By adding condensate, viscosity of each sample reduced. Gas condensate had a greater impact on heavier oil; however, at higher temperatures its effect was reduced. Diluting with naphtha decreased heavy oil viscosity in the same way as n-heptane and toluene. Besides experimental investigation, different viscosity models were evaluated for prediction of heavy oil/solvent viscosity. It was recognized that Lederer' model is the best one.

  9. Formação inicial de professores através do recurso ao património artístico local relevando o trabalho experimental

    OpenAIRE

    Paixão, Fátima; Jorge, Fátima

    2017-01-01

    O estudo insere-se na linha da interação entre contexto formal e não formal através da exploração de conexões da exploração de conexões entre ciência e arte proporcionadas pelo património local. Tendo como finalidade contribuir para a abertura curricular da escola através da formação inicial de professores, definimos como objetivos planificar e implementar uma atividade experimental no Ensino Básico integrando aprendizagens na escola e num Museu e analisar o desenvolvimento profissional de um...

  10. Experimental and theoretical studies of the laws governing condensate deposition from combustion gases

    Science.gov (United States)

    Rosner, D. E.; Seshadri, K.

    1981-01-01

    A description is presented of the results of a research program directed at an improved understanding of condensate deposition rate phenomena in combustion systems. The conducted experiments make use of real-time optical laser reflectance-interference-polarization techniques in flame environments. The obtained new data and the results of previous gravimetric experiments are employed as a basis for the development of a comprehensive convective diffusion deposition theory, taking into account the assumption of a multicomponent vapor or multisize class particles 'source-free' boundary layer. The theory makes it possible to provide self-consistent salt/ash/soot deposition rate predictions over a wide variety of environmental conditions.

  11. Experimental analysis on the use of condensing boilers for centralized production of domestic hot water

    Energy Technology Data Exchange (ETDEWEB)

    Cirillo, E.; Lazzarin, R.; Piccininni, F.; Caliari, R. (Bari Univ. (Italy). Ist. di Fisica Tecnica ed Impianti Termotecnici)

    1988-11-01

    The monthly performance of pulse combustion condensing boilers has been studied. The boilers are utilized in a plant for the centralized production of domestic hot water. The heating capacity is 112 kW with a daily production of 15 cubic meter of hot waters at 60 degrees centigrade. The analysis has shown the very good seasonal performance of the boilers even without a suitable plant design. The great importance of the heat distribution system has been outlined in order to reach good overall performance.

  12. Experimental Study of Underground Irrigation by Condensation of Humid Air in Perforated Pipes

    OpenAIRE

    Lindblom, Jenny; Nordell, Bo

    2012-01-01

    A small scale Condensation Irrigation (CI) system was constructed to investigate the flow patterns of water, air and heat in the soil surrounding a perforated pipe from which water, heat and humid air was transferred. A 0.2 m long cross-section of sand and pipe was used to emulate a two-dimensional section of a CI system. Under these downscaled conditions, the mean irrigation rate in the sand box was 1.03 mm d-1. The major heat transfer mechanism in the sand profile was gas advection, which g...

  13. Experimental results for an experimental condensation heat exchanger with a spiral minichanel tube. Comparison to numerical imulations

    Directory of Open Access Journals (Sweden)

    Hrubý J.

    2013-04-01

    Full Text Available The paper describes new results for an experimental heat exchanger equipped with a single corrugated capillary tube, basic information about the measurements and the experimental setup. Some of the results were compared with numerical simulations.

  14. Infrared characteristic radiation of water condensation and freezing in connection with atmospheric phenomena; Part 3: Experimental data

    Science.gov (United States)

    Tatartchenko, V.; Liu, Yifan; Chen, Wenyuan; Smirnov, P.

    2012-09-01

    This paper is the third one from the series of papers with the same titles published in this journal. The papers consider the infrared characteristic radiation (IRCR) during the first order phase transitions of water: crystallization, water vapor condensation, and water vapor deposition. Experimental results are analyzed in terms of their correspondence to the theoretical model. This model is based on the assertion that the particle's (atom, molecule, or cluster) transition from the higher energetic level in a metastable phase (vapor or liquid) to a lower level in a stable phase (liquid or crystal) produces an emission of one or more photons. The energy of these photons depends on the latent energy of the phase transition and the character of bonds formed by the particle in the new phase. For all investigated substances, this energy falls in the infrared range. Recorded in the atmosphere, numerous sources of the infrared radiation seem to be a result of crystallization, condensation and deposition of water during fog and cloud formation. The effect under investigation must play a very important role in atmospheric phenomena: it is one of the sources of Earth's cooling; formation of hailstorm clouds is accompanied by intensive IRCR that could be detected for process characterization and meteorological warnings. IRCR seems to be used for atmospheric energy accumulation and together with the wind, falling water, solar and geothermal energies makes available the fifth source of ecologically pure energy.

  15. Compact experimental apparatus for producing high-repetition-rate 87Rb Bose-Einstein condensation on an atom chip

    Science.gov (United States)

    Yu, Hoon; Kim, Seung Jin; Moon, Ye Lin; Kim, Jung Bog; Lee, Jin Seung

    2013-08-01

    We construct a compact experimental apparatus for producing high-repetition-rate ultra cold 87Rb atom based on an external atom chip. Initially, we produce an atomic flux from a 2D+ MOT (magneto-optical trap) in a nearly isolated 2D+ MOT chamber and improve the flux by adjusting the cooling beam detuning of the 2D+ MOT. The flux is trapped in the 3D MOT for 1.2 s and is further cooled by performing compressing the MOT for 20 ms and using polarization gradient cooling for 6.2 ms. After optical pumping into the 5 S F = 2 ( m F = 2) ground state, we transport atoms toward the chip surface by performing external Z coil trapping. At 1 mm below the chip surface, the external Z coil trap is completely switched to an atom chip trap by using a Z wire and a dimple wire on the chip with external bias fields. The transport and the switching take totally 520 ms. The number of atoms trapped on the atom chip is measured to be about 2 × 107. After the atoms has been compressed for 100 ms to increase trap frequencies, we perform RF evaporative cooling in the RF frequency range from 32 MHz to 6.82 MHz for 2.4 seconds. The final number of atoms in the atomic cloud after RF cooling is 1.2 × 105 atoms, and we are able to observe some Bose-Einstein condensation. The repetition rate for producing the condensation is 0.234 Hz. In this paper, we describe our experimental apparatus and processes.

  16. The Effect of Non-condensable Gases Removal on Air Gap Membrane Distillation: Experimental and Simulation Studies

    KAUST Repository

    Alsaadi, Ahmad S.

    2014-04-01

    In the kingdom of Saudi Arabia (KSA), the current seawater desalination technologies are completely relying on burning unsustainable crude oil as their main energy driver. Saudi authorities have realized that the KSA is not going to be protected from the future global energy crisis and have started to set up a plan to diversify its energy resources. Membrane Distillation (MD) has emerged as an attractive alternative desalination process. It combines advantages from both thermal and membrane-based technologies and holds the potential of being a cost-effective separation process that can utilize low-grade waste heat or renewable energy. MD has four different configurations; among them is Air Gap Membrane Distillation (AGMD) which is the second most commonly tested and the most commercially available pilot-plant design. AGMD has a stagnant thin layer of air between the membrane and the condensation surface. This layer introduces a mass transfer resistance that makes the process require a large membrane surface area if a large quantity of fresh water is desired. This dissertation reports on experimental and theoretical work conducted to enhance the AGMD flux by removing non-condensable gases from the module and replacing it with either vacuum, liquid water or porous materials. At first, a mathematical model for AGMD was developed and validated experimentally to create a baseline for improvements that could be achieved after the removal of non-condensable gases. The mathematical model was then modified to simulate the process under vacuum where it showed a flux enhancement that reached 286%. The Water Gap Membrane Distillation (WGMD) configuration improved the flux by almost the same percentage. Since enhancing the flux is expected to increase temperature polarization effects, a theoretical study was conducted on the effect of temperature polarization in a Vacuum Membrane Distillation (VMD) configuration. The study showed that the effect of temperature polarization at

  17. Single molecule experimentation in biological physics: exploring the living component of soft condensed matter one molecule at a time.

    Science.gov (United States)

    Harriman, O L J; Leake, M C

    2011-12-21

    The soft matter of biological systems consists of mesoscopic length scale building blocks, composed of a variety of different types of biological molecules. Most single biological molecules are so small that 1 billion would fit on the full-stop at the end of this sentence, but collectively they carry out the vital activities in living cells whose length scale is at least three orders of magnitude greater. Typically, the number of molecules involved in any given cellular process at any one time is relatively small, and so real physiological events may often be dominated by stochastics and fluctuation behaviour at levels comparable to thermal noise, and are generally heterogeneous in nature. This challenging combination of heterogeneity and stochasticity is best investigated experimentally at the level of single molecules, as opposed to more conventional bulk ensemble-average techniques. In recent years, the use of such molecular experimental approaches has become significantly more widespread in research laboratories around the world. In this review we discuss recent experimental approaches in biological physics which can be applied to investigate the living component of soft condensed matter to a precision of a single molecule. © 2011 IOP Publishing Ltd Printed in the UK & the USA

  18. New experimental setup for boron isotopes separation by laser assisted retardation of condensation method

    Energy Technology Data Exchange (ETDEWEB)

    Lyakhov, K. A.; Lee, H. J. [Institute for Nuclear Science and Technology, Jeju (Korea, Republic of)

    2013-05-15

    Proposed static model corresponds to the two-cycle iterative scheme for boron isotopes separation. This rather simple model helps to understand combined action of all important parameters and relations between them on boron isotopes separation by SILARC method. These parameters include carrier gas choice, molar fraction at what BCl{sub 3} gas is dissolved in carrier gas, laser intensity, providing minimum of energy expenses and the largest output, optimal gas pressure and temperature in backing and downstream chambers, optimal irradiation cell and skimmer chamber dimensions, optimal nozzle throughput. It was suggested a method for finding optimal values of these parameters based on global minimum or energy spent on production of unit of isotope, which is analog of Separative Work Unit (SWU). It was shown that the most optimal carrier gas, corresponding to this minimum, among other considered-N{sub 2},NO{sub 2},SF{sub 6}, is Ar. Restriction on the maximal irradiation chamber length, caused by dimerization rate, is also considered. Two types of industrial scale irradiation cells are compared. The first one has the only large throughput slit nozzle, while the second one has numerous small nozzles arranged in parallel arrays for better overlap with laser beam. It is shown that the last one outperforms the former one significantly. We calculated that our experimental setup, provided argon is used as a carrier gas, can yield ∼50mg/hr of boron-10. It is interesting to compare this production rate with traditional method of industrial boron isotopes separation by low temperature distillation, Ref. In this method production rate is practically the same, but energy expenses per separated isotope are substantially smaller: ∼1 eV/atom instead of ∼10{sup 3} eV/atom as for SILARC method. The largest fraction of energy expenses in our SILARC-based method comes from compressor operation.

  19. An Experimental Investigation of the Effect of Condensate Inundation on Heat-Transfer in a Horizontal Tube Bundle.

    Science.gov (United States)

    1980-03-01

    C-1) allows the isolation of the test condenser hotwell for condensate measurement. Since house steam was used as the steam supply system, the...Dans in Faiscean Tubulaire Horizontal," Department of Transfer and Conversion of Energy Service of Thermic Transfers, France, 1978. 13. Kline, S. J

  20. Condensation Polymerization

    Indian Academy of Sciences (India)

    chain polyester by a process termed as polycondensation – 'poly' implying that several such events occur, and 'condensation' im- plies that there is a condensate that is formed. The condensate formed in this case, as you would have guessed, is H2O. Such re- actions would be classified as AA + BB type condensation, anal ...

  1. The production of hot sanitary water by condensing boilers: Analysis of the seasonal experimental results of a central heating plant

    Energy Technology Data Exchange (ETDEWEB)

    Caliari, R.; Cirillo, E.; Lazzarin, R.; Piccininni, F.

    1988-12-01

    The use of condensing boilers in the production of hot sanitary water clearly evidences their advantages, since the highest operating temperatures are only around 60/degree/C. This paper examines performance test results relevant to a central heating plant (serving a residential area in Rovereto, Italy) with 112 kW of thermal power. The analysis reveals the excellent performance characteristics of the condensing boilers and points out the importance of proper management of the recirculation system.

  2. CONDENSATION OF WATER VAPOR IN A VERTICAL TUBE CONDENSER

    Directory of Open Access Journals (Sweden)

    Jan Havlík

    2015-10-01

    Full Text Available This paper presents an analysis of heat transfer in the process of condensation of water vapor in a vertical shell-and-tube condenser. We analyze the use of the Nusselt model for calculating the condensation heat transfer coefficient (HTC inside a vertical tube and the Kern, Bell-Delaware and Stream-flow analysis methods for calculating the shell-side HTC from tubes to cooling water. These methods are experimentally verified for a specific condenser of waste process vapor containing air. The operating conditions of the condenser may be different from the assumptions adopted in the basic Nusselt theory. Modifications to the Nusselt condensation model are theoretically analyzed.

  3. Roles of emeriti professors

    OpenAIRE

    Thody, Angela

    2008-01-01

    Emeritus Professor Angela Thody commenced a study of emeriti professors in 2006 when she herself had become an emeritus in 2003 and was seeking to establish an Association for emeriti at her university at Lincoln. By 2008, the literature review was finished and a pilot study of emeriti professors at Leicester University was underway. This presentation was one of several to the University of Lincoln's College of Professors to encourage their support for the formation of the association and to ...

  4. PROFESSOR ENSERMU KELBESSA

    African Journals Online (AJOL)

    2016-08-14

    Aug 14, 2016 ... University, Sweden in 1990. Although still very young, Professor Ensermu Kelbessa joined the Addis Ababa. University's Biology Department as a graduate assistant in 1979. He then went on to serve the university in various positions including: Lecturer, Assistant Professor, Associate. Professor and, finally ...

  5. Experimental study of heat transfer during pseudo-dropwise condensation of water-ethanol and water-isopropanol vapor mixtures on a vertical tube

    Science.gov (United States)

    Chindyakov, A. A.; Smirnov, Yu B.; Vinogradov, A. A.; Mikhailova, E. V.

    2017-11-01

    In the present study experimental heat transfer data on condensation of almost immobile water-ethanol and water-isopropanol vapor mixtures on the vertical smooth copper tube 100 mm long with an outer diameter of 12.0 mm were obtained. Experiments for water-ethanol mixture were carried out at mass concentrations of ethanol from 0.4 to 16% in the vapor phase, and for a water-isopropanol mixture - from 0.6 to 8.4%. The pressure was 0.12…0.13 MPa, vapor-to-surface temperature difference varied from 2 to 40K. The experimental data are represented as dependency of heat transfer coefficient and heat flux on the vapor-to-surface temperature difference. The results of high-speed photography of the condensation process are discussed. It is noted that the transition from film mode to pseudo-dropwise condensation occurs when vapor-to-surface temperature difference is close to dew point - bubble point temperature difference for a given composition of the mixture. According to experimental data, the diffusion thermal resistance and thermal resistance of the liquid phase at different concentrations of the mixture were calculated.

  6. Condensation heat transfer of a pure fluid and binary mixture outside a bundle of smooth horizontal tubes. Comparison of experimental results and a classical model

    Energy Technology Data Exchange (ETDEWEB)

    Belghazi, M.; Signe, J.C.; Marvillet, C. [Commissariat a l' Energie Atomique, Grenoble (France). Groupement pour la Recherche sur les Echangeurs Thermiques; Bontemps, A. [Universite Joseph Fourier, Grenoble (France)

    2001-12-01

    The condensation of pure HFC134a and different zeotropic mixtures with pure HFC134a and HFC23 on the outside of a bundle of smooth tubes was studied. The local heat transfer coefficient for each row was experimentally determined using a test section composed by a 13x3 staggered bundle of smooth copper tubes, measuring cooling water temperature in the inlet and the outlet of each tube, and measuring the vapour temperature along the bundle. All data were taken at the inlet vapour temperature of 40{sup o}C with a wall subcooling ranging from 4 to 26 K. The heat flux was varied from 5 to 30 kW/m{sup 2} and the cooling water flow rate from 120 to 300 1/h for each tube. The visualisation of the HFC134a condensate flow by means of transparent glass tubes reveals specific flow patterns and explains the difference between the measured values of the heat transfer coefficient and the calculated values from Nusselt's theory. On the other hand, the experimental heat transfer data with the binary mixtures HFC23-HFC134a show the important effects of temperature glide and the strong decrease of the heat transfer coefficient in comparison with the pure HFC134a data. The measured values with the different zeotropic mixtures were compared with the data calculated with the classical condensation model based on the equilibrium model. An improvement of this model is proposed. (author)

  7. Experimental Investigation of Operation of VVER Steam Generator in Condensation Mode in the Event of the Severe Accident

    Energy Technology Data Exchange (ETDEWEB)

    Morozov, Andrey [Institute for Physics and Power Engineering by A.I. Leypunsky, 1 Bondarenko sq. Obninsk, 249033 (Russian Federation)

    2008-07-01

    For new Russian nuclear power plants with VVER-1200 reactor in the event of a beyond design basis accident, provision is made for the use of passive safety systems for necessary core cooling. These safety systems include the passive heat removal system (PHRS). In the case of leakage in the primary circuit this system assures the transition of steam generators (SG) to operation in the mode of condensation of the primary circuit steam. As a result, the condensate from SG arrives at the core providing its additional cooling. To investigate the condensation mode of VVER SG operation, a large scale HA2M-SG test facility was constructed. The rig incorporates: buffer tank, SG model with scale is 1:46, PHRS heat exchanger. Experiments at the test facility have been performed to investigate condensation mode of operation of SG model at the pressure 0.4 MPa, correspond to VVER reactor pressure at the last stage of the beyond design basis accident. The report presents the test procedure and the basic obtained test results. (authors)

  8. Professor Volker Claus: vom o. Professor zum e-Professor

    Science.gov (United States)

    Gunzenhäuser, Rul; Taras, Christiane; Wörner, Michael

    Der Beitrag würdigt das Wirken von Professor Claus auf Gebieten des rechnerunterstützten Lehrens. Dabei wird ein Bogen von den frühen Systemen des rechnerunterstützten Lehrens über moderne Lernplattformen im Internet zu neuen Anwendungen web-basierter Systeme für das lebenslange Lehren und Lernen gespannt.

  9. CONDENSATION CAN

    Science.gov (United States)

    Booth, E.T. Jr.; Pontius, R.B.; Jacobsohn, B.A.; Slade, C.B.

    1962-03-01

    An apparatus is designed for condensing a vapor to a solid at relatively low back pressures. The apparatus comprises a closed condensing chamber, a vapor inlet tube extending to the central region of the chamber, a co-axial tubular shield surrounding the inlet tube, means for heating the inlet tube at a point outside the condensing chamber, and means for refrigeratirg the said chamber. (AEC)

  10. Water Condensation

    DEFF Research Database (Denmark)

    Jensen, Kasper Risgaard; Fojan, Peter; Jensen, Rasmus Lund

    2014-01-01

    The condensation of water is a phenomenon occurring in multiple situations in everyday life, e.g., when fog is formed or when dew forms on the grass or on windows. This means that this phenomenon plays an important role within the different fields of science including meteorology, building physics......, and chemistry. In this review we address condensation models and simulations with the main focus on heterogeneous condensation of water. The condensation process is, at first, described from a thermodynamic viewpoint where the nucleation step is described by the classical nucleation theory. Further, we address...

  11. Water interactions with condensed organic phases: a combined experimental and theoretical study of molecular-level processes

    Science.gov (United States)

    Johansson, Sofia M.; Kong, Xiangrui; Thomson, Erik S.; Papagiannakopoulos, Panos; Pettersson, Jan B. C.; Lovrić, Josip; Toubin, Céline

    2016-04-01

    Water uptake on aerosol particles modifies their chemistry and microphysics with important implications for air quality and climate. A large fraction of the atmospheric aerosol consists of organic aerosol particles or inorganic particles with condensed organic components. Here, we combine laboratory studies using the environmental molecular beam (EMB) method1 with molecular dynamics (MD) simulations to characterize water interactions with organic surfaces in detail. The over-arching aim is to characterize the mechanisms that govern water uptake, in order to guide the development of physics-based models to be used in atmospheric modelling. The EMB method enables molecular level studies of interactions between gases and volatile surfaces at near ambient pressure,1 and the technique may provide information about collision dynamics, surface and bulk accommodation, desorption and diffusion kinetics. Molecular dynamics simulations provide complementary information about the collision dynamics and initial interactions between gas molecules and the condensed phase. Here, we focus on water interactions with condensed alcohol phases that serve as highly simplified proxies for systems in the environment. Gas-surface collisions are in general found to be highly inelastic and result in efficient surface accommodation of water molecules. As a consequence, surface accommodation of water can be safely assumed to be close to unity under typical ambient conditions. Bulk accommodation is inefficient on solid alcohol and the condensed materials appear to produce hydrophobic surface structures, with limited opportunities for adsorbed water to form hydrogen bonds with surface molecules. Accommodation is significantly more efficient on the dynamic liquid alcohol surfaces. The results for n-butanol (BuOH) are particularly intriguing where substantial changes in water accommodation taking place over a 10 K interval below and above the BuOH melting point.2 The governing mechanisms for the

  12. Condensed-Matter Physics.

    Science.gov (United States)

    Hirsch, Jorge E.; Scalapino, Douglas J.

    1983-01-01

    Discusses ways computers are being used in condensed-matter physics by experimenters and theorists. Experimenters use them to control experiments and to gather and analyze data. Theorists use them for detailed predictions based on realistic models and for studies on systems not realizable in practice. (JN)

  13. Condensation Polymerization

    Indian Academy of Sciences (India)

    Condensation polymerizations, as thename suggests, utilizes bond-forming reactions that generatea small molecule condensate, which often needs to be continuouslyremoved to facilitate the formation of the polymer. Inthis article, I shall describe some of the essential principles ofcondensation polymerizations or more ...

  14. A Professor's Work.

    Science.gov (United States)

    Melko, Matthew

    This book describes a year-long participant-observer case study of the professorship as a profession. Following an introductory chapter, each chapter examines one aspect of the professor's occupation by recounting the specific experiences of the author, a sociology professor at Wright State University (Ohio). Chapter 2 looks at the department as…

  15. Flue gas condensation in oxyfuel power plants. Heat- and mass transfer measurements and experimental validation of an efficient condensation concept; Rauchgaskondensation in Oxyfuel-Kraftwerken. Waerme- und Stoffuebergangsmessungen sowie experimentelle Validierung eines effizienten Kondensationskonzepts

    Energy Technology Data Exchange (ETDEWEB)

    Raindl, Markus

    2010-12-06

    Condensation of a steam-inert gas mixture in an Oxyfuel condenser differs significantly from condensation of pure steam: condenser pressure and rest gas content increase dramatically, heat- and mass transfer coefficients are lower and oversaturation of the steam-inert gas mixture yields to fog formation. In the context of this thesis, therefore, at first the optimal ranges of working parameters for Oxyfuel processes calculated. In the following some heat flux measurements were carried out on a horizontal, crossflow pipe to validate various heat- and mass transfer theories. Building on these results a new, efficient condensation concept was developed to reduce fog formation. The final results of the measurements with a laboratory model show great performance regarding fog reduction and condensation efficiency. (orig.)

  16. Condensed Matter Field Theory

    Science.gov (United States)

    Altland, Alexander; Simons, Ben

    2006-06-01

    Over the past few decades, in concert with ground-breaking experimental advances, condensed matter theory has drawn increasingly from the language of low-energy quantum field theory. This primer is aimed at elevating graduate students of condensed matter theory to a level where they can engage in independent research. It emphasizes the development of modern methods of classical and quantum field theory with applications oriented around condensed matter physics. Topics covered include second quantization, path and functional field integration, mean-field theory and collective phenomena, the renormalization group, and topology. Conceptual aspects and formal methodology are emphasized, but the discussion is rooted firmly in practical experimental application. As well as routine exercises, the text includes extended and challenging problems, with fully worked solutions, designed to provide a bridge between formal manipulations and research-oriented thinking. This book will complement graduate level courses on theoretical quantum condensed matter physics. Spans the field of modern condensed matter theory focusing on field theory techniques Written to facilitate learning, with numerous challenging exercises, with fully worked solutions, aimed at physicists starting graduate-level courses The theoretical methods are firmly set in concrete experimental applications

  17. Professor Martin Hairer

    Directory of Open Access Journals (Sweden)

    Martine Barons

    2015-09-01

    Full Text Available Professor Martin Hairer was one of four recipients of the 2014 Fields Medal, widely viewed as the highest honour a mathematician can receive. He is currently Regius Professor of Mathematics in the Mathematics Department at the University of Warwick. Professor Hairer has contributed significantly to the field of stochastic partial differential equations (SPDEs, which engages with interdisciplinary approaches to mathematics and physics. He has enjoyed great success communicating mathematics to a range of audiences and has also developed music editing software.In this interview, early career mathematicians, Dr Martine Barons (MJB and Dr Paul Chleboun ask Professor Hairer (MH about how his interest in mathematics developed; the awards ceremony where he received the Fields Medal; Amadeus Pro, the music software he developed and continues to maintain; and the challenges of engaging a sceptical and sometimes critical public as a mathematician.

  18. An experimental study of chondrule formation from chondritic precursors via evaporation and condensation in Knudsen cell: Shock heating model of dust aggregates

    Science.gov (United States)

    Imae, Naoya; Isobe, Hiroshi

    2017-09-01

    Chondrules, igneous objects of ∼1 mm in diameter, formed in the earliest solar system via a transient heating event, are divided into two types: main (type I, FeO-poor) and minor (type II, FeO-rich). Using various chondritic materials for different redox conditions and grain sizes, chondrule reproduction experiments were carried out at IW-2 to IW-3.8, with cooling rates mainly ∼100°C/h, with peak temperatures mainly at 1450 °C, and mainly at 100 Pa in a Knudsen cell providing near chemical equilibrium between the charge and the surrounding gas at the peak temperatures. Vapor pressures in the capsule were controlled using solid buffers. After and during the significant evaporation of the iron component from the metallic iron-poor starting materials in near equilibrium, crystallization occurred. This resulted in the formation of a product similar to the type I chondrules. Dusty olivine grains occurred in charges that had precursor type II chondrules containing coarse ferroan olivine, but such grains are not common in type I chondrules. Therefore fine-grained ferroan matrices rather than type II chondrules are main precursor for type I chondrules. The type I chondrules would have evolved via evaporation and condensation in the similar conditions to the present experimental system. Residual gas, which escaped in experiments, could have condensed to form matrices, leading to complementary compositions. Clusters of matrices and primordial chondrules could have been recycled to form main-generation chondrules originated from the shock heating.

  19. An experimental station for advanced research on condensed matter under extreme conditions at the European Synchrotron Radiation Facility - BM29 beamline

    Science.gov (United States)

    Filipponi, Adriano; Borowski, Michael; Bowron, Daniel T.; Ansell, Stuart; Di Cicco, Andrea; De Panfilis, Simone; Itiè, Jean-Paul

    2000-06-01

    We describe state-of-the-art experimental techniques using the beamline BM29 of the European Synchrotron Radiation Facility (ESRF). This station exploits the unique characteristics of an ESRF bending magnet source to provide a tunable, collimated, x-ray beam to perform high quality x-ray absorption spectroscopy within the energy range of E=5-75 keV using Si(111), Si(311), and Si(511) crystal pairs. Energy scans can be performed over this wide energy range with excellent reproducibility, stability and resolution, usually better than ΔE/E≃5×10-5. The experimental setup has been exploited to study condensed matter under extreme conditions. We describe here two sample environment devices; the L' Aquila-Camerino oven for high-temperature studies up to 3000 K in high vacuum and the Paris-Edinburgh press suitable for high-pressure high-temperature studies in the range 0.1-7 GPa and temperatures up to 1500 K. These devices can be integrated in an experimental setup which combines various control and detection systems suitable to perform x-ray absorption spectroscopy, x-ray absorption temperature scans, and energy scanning x-ray diffraction (ESXD). The ESXD setup is based on a scintillator detector behind a fixed angle collimator aligned to the sample. The combination of these three measurements, which can be performed in rapid sequence on the sample during the experiment, provides an essential tool for structural investigations and in situ sample characterization.

  20. Benzoin Condensation

    Indian Academy of Sciences (India)

    ART

    Roots of cassava (tapioca), an important food crop in many countries of the world, including India, contain acetone cyanohy- drin glucoside called linamarin. ..... The replacement of cyanide by the harmless thiazolium salts as catalysts for benzoin condensation is one of the finest examples of Green Chemistry in action. S. N.

  1. Professor Michael Levitt

    Directory of Open Access Journals (Sweden)

    Gemma-Louise Davies

    2015-10-01

    Full Text Available Professor Michael Levitt (Stanford University, USA won the 2013 Nobel Prize in Chemistry for the development of multiscale models for complex chemical systems—computational tools which can calculate the course of chemical reactions. Professor Levitt was born in Pretoria, South Africa; he came to the UK on a summer vacation aged 16, where he decided to stay and study for his A‑levels. His interest in the physics of living systems drove him to study biophysics at King’s College London, before securing a PhD position at the Laboratory of Molecular Biology in Cambridge. In the interim year between his degree and beginning his PhD, Professor Levitt worked at the Weizmann Institute of Science in Israel, where he met his future wife. They married later that year and moved to Cambridge, where their three children were born. After completing his PhD, he spent time working in Israel, Cambridge, the Salk Institute and Stanford (both California. Since 1986, he has split his time between Israel and California. Outside of science, he is a keen hiker and he is well-known to have attended the eclectic ‘Burning Man’ Festival in California.[1]Professor Levitt visited the University of Warwick to speak at the Computational Molecular Science Annual Conference in March 2015. In this interview, Dr Gemma-Louise Davies, an Institute of Advanced Study Global Research Fellow, spoke to Professor Levitt about the importance of Interdisciplinarity in his field, role models in Academia, and his plans for the future.Image: Professor Michael Levitt (left with Dr Scott Habershon (right, organiser of the 2015 Computational Molecular Science Annual Conference during his visit to the University of Warwick in March 2015.[1] ‘Burning Man’ is a unique annual festival dedicated to community, art, music, self-expression and self-reliance. Tens of thousands of people flock to this temporary metropolis built in the Californian desert.

  2. Professor Kalkman retires

    NARCIS (Netherlands)

    Baas, Pieter

    1991-01-01

    On 13 December 1990 Prof. Dr. Cornelis (Kees) Kalkman retired from the positions of Professor of Plant Systematics and Scientific Director of the Rijksherbarium/ Hortus Botanicus by presenting his valedictory lecture to the academic community of Leiden University and the assembled Dutch Botanical

  3. Professor Wolfgang Panofsky

    CERN Multimedia

    2007-01-01

    "Professor Wolfgang panofsky, who died on September 24 aged 88, was a particle physicists and director of the Stanford Linear Accelerator Centre (SLAC) in California; with Jack Steinberger, he was the first to isolate the neutral pi meson, one of the subatomic particles which had been predicted by theoretical scientists to account for the strng force which binds the nuclei of atoms." (1 page)

  4. Professor Tiina Tasmuth Helsingis

    Index Scriptorium Estoniae

    2000-01-01

    Tervisekasvatuse õppetooli professor Tiina Tasmuth osales 11.-14. juunini Helsingis toimunud rahvusvahelise konverentsi "2nd Psycho-Social Impacts of Breast Cancer" töös ning esines ettekandega teemal "Chronic post-treatment symptoms in patients with breast cancer" : [täistekst

  5. Professor og DMI

    DEFF Research Database (Denmark)

    Kaas, Eigil

    2010-01-01

    oplever meget lave temperaturer - og for Danmarks vedkommende en usædvanlig lang periode med vintervejr. Forklaringen kommer fra professor Eigil Kaas fra Niels Bohr Instituttet ved Københavns Universitet. Han forklarer til jp.dk, at vintervejret dog er betinget af den mere eller mindre tilfældige måde...

  6. Professors' Observations on Their Work.

    Science.gov (United States)

    Myers, Betty; Mager, Gerald M.

    Previous studies of professors of education have noted what activities comprised the work of being a professor, how professors allocated time to the various work tasks, how they would have preferred to allocate time, and insights they had about their work. In this study, parallel data were gathered on the broader education professoriate. Survey…

  7. An overview of Experimental Condensed Matter Physics in Argentina by 2014, and Oxides for Non Volatile Memory Devices: The MeMOSat Project

    Science.gov (United States)

    Levy, Pablo

    2015-03-01

    In the first part of my talk, I will describe the status of the experimental research in Condensed Matter Physics in Argentina, biased towards developments related to micro and nanotechnology. In the second part, I will describe the MeMOSat Project, a consortium aimed at producing non-volatile memory devices to work in aggressive environments, like those found in the aerospace and nuclear industries. Our devices rely on the Resistive Switching mechanism, which produces a permanent but reversible change in the electrical resistance across a metal-insulator-metal structure by means of a pulsed protocol of electrical stimuli. Our project is devoted to the study of Memory Mechanisms in Oxides (MeMO) in order to establish a technological platform that tests the Resistive RAM (ReRAM) technology for aerospace applications. A review of MeMOSat's activities is presented, covering the initial Proof of Concept in ceramic millimeter sized samples; the study of different oxide-metal couples including (LaPr)2/3Ca1/3MnO, La2/3Ca1/3MnO3, YBa2Cu3O7, TiO2, HfO2, MgO and CuO; and recent miniaturized arrays of micrometer sized devices controlled by in-house designed electronics, which were launched with the BugSat01 satellite in June2014 by the argentinian company Satellogic.

  8. Condensation in Nanoporous Packed Beds.

    Science.gov (United States)

    Ally, Javed; Molla, Shahnawaz; Mostowfi, Farshid

    2016-05-10

    In materials with tiny, nanometer-scale pores, liquid condensation is shifted from the bulk saturation pressure observed at larger scales. This effect is called capillary condensation and can block pores, which has major consequences in hydrocarbon production, as well as in fuel cells, catalysis, and powder adhesion. In this study, high pressure nanofluidic condensation studies are performed using propane and carbon dioxide in a colloidal crystal packed bed. Direct visualization allows the extent of condensation to be observed, as well as inference of the pore geometry from Bragg diffraction. We show experimentally that capillary condensation depends on pore geometry and wettability because these factors determine the shape of the menisci that coalesce when pore filling occurs, contrary to the typical assumption that all pore structures can be modeled as cylindrical and perfectly wetting. We also observe capillary condensation at higher pressures than has been done previously, which is important because many applications involving this phenomenon occur well above atmospheric pressure, and there is little, if any, experimental validation of capillary condensation at such pressures, particularly with direct visualization.

  9. The Effects of Professors' Race and Gender on Student Evaluations and Performance

    Science.gov (United States)

    Basow, Susan A.; Codos, Stephanie; Martin, Julie L.

    2013-01-01

    This experimental study examined the effects of professor gender, professor race, and student gender on student ratings of teaching effectiveness and amount learned. After watching a three-minute engineering lecture presented by a computer-animated professor who varied by gender and race (African American, White), female and male undergraduates…

  10. 16 December 2013 - Hooke Professor of Experimental Physics and Pro Vice Chancellor University of Oxford Prof. I. Walmsley visiting the ATLAS cavern with ATLAS Collaboration Deputy Spokesperson T. Wengler, Physics Department, ATLAS Collaboration P. Wells and Chair, CMS Collaboration Board, Oxford University and Purdue University I. Shipsey

    CERN Multimedia

    Anna Pantelia

    2013-01-01

    16 December 2013 - Hooke Professor of Experimental Physics and Pro Vice Chancellor University of Oxford Prof. I. Walmsley visiting the ATLAS cavern with ATLAS Collaboration Deputy Spokesperson T. Wengler, Physics Department, ATLAS Collaboration P. Wells and Chair, CMS Collaboration Board, Oxford University and Purdue University I. Shipsey

  11. Professor Stewart's incredible numbers

    CERN Document Server

    Stewart, Ian

    2015-01-01

    Ian Stewart explores the astonishing properties of numbers from 1 to10 to zero and infinity, including one figure that, if you wrote it out, would span the universe. He looks at every kind of number you can think of - real, imaginary, rational, irrational, positive and negative - along with several you might have thought you couldn't think of. He explains the insights of the ancient mathematicians, shows how numbers have evolved through the ages, and reveals the way numerical theory enables everyday life. Under Professor Stewart's guidance you will discover the mathematics of codes,

  12. Professor Alex Callinicos

    Directory of Open Access Journals (Sweden)

    Ali Saqer

    2016-04-01

    Full Text Available Professor Alex Callinicos is a renowned social theorist and scholar of international political economy. He conducts research on Marx and Marxism, European social and political theory, contemporary political philosophy, critical theory, historiography, and international political economy. His work provides invaluable insights on issues of race and racism, social justice, the Third Way, imperialism, austerity, and EU politics, among many other fascinating contemporary issues. Alex studied Philosophy, Politics, and Economics at Balliol College, Oxford, and Philosophy of Science at the London School of Economics before writing a DPhil on Marx's Capital, also at Balliol. He was a Junior Research Fellow in Contemporary Social Thought at St Peter's College, Oxford from 1979 to 1981, after which he taught social and political theory at the Department of Politics at the University of York until 2005, when he moved to King's College London. Alex is currently the Professor of European Studies at King's and editor of International Socialism. Alex has been an active contributor to the development of the movement for another globalization, participating in the World Social Forum and an animator of the European Social Forum. Among his best known books are The Revolutionary Ideas of Karl Marx (1983, Against Postmodernism (1990, Social Theory (1999, An Anti-Capitalist Manifesto (2003, The Resources of Critique (2006, Imperialism and Global Political Economy (2009. His most recent book is entitled Deciphering Capital: Marx’s Capital and its Destiny (2014.

  13. Evidence for a palaeo-oil column and alteration of residual oil in a gas-condensate field: Integrated oil inclusion and experimental results

    Science.gov (United States)

    Bourdet, Julien; Burruss, Robert C.; Chou, I.-Ming; Kempton, Richard; Liu, Keyu; Hung, Nguyen Viet

    2014-10-01

    displays a similar yellow shift when gas is added. Solid residues rarely form in mixtures with 42 °API oil. FT-IR spectra suggest that the decrease of fluorescence intensity of the original oil at short wavelengths to be due to the partitioning of low molecular weight aromatic molecules into the vapour phase and/or the new immiscible liquid phase. The decrease of fluorescence intensity at long wavelengths appears to be due to loss of high molecular weight aromatics during precipitation of solid residues by desorption of aromatics and resins from asphaltenes. Desorption of low molecular weight aromatics and resins from asphaltenes during precipitation can also increase the fluorescence intensity at short wavelengths of the residual oil. Water clearly affects the precipitation of semi-solid residues from the oil phase of the lowest API gravity oil. The change of hydrocarbon phase(s) in UV-visible fluorescence and FT-IR enclosed within the FSCCs were compared with the fluorescence patterns of natural fluid inclusions at Phuong Dong gas condensate field. The experimental results support the concept of gas-washing of residual oil and are consistent with the oil inclusion attributes from the current gas zone at Phuong Dong field. The hydrocarbon charge history of the fractured granite reservoir is interpreted to result from the trapping of residual oil after drainage of a palaeo-oil column by gas.

  14. The physics of exciton-polariton condensates

    CERN Document Server

    Lagoudakis, Konstantinos

    2013-01-01

    In 2006 researchers created the first polariton Bose-Einstein condensate at 19K in the solid state. Being inherently open quantum systems, polariton condensates open a window into the unpredictable world of physics beyond the “fifth state of matter”: the limited lifetime of polaritons renders polariton condensates out-of-equilibrium and provides a fertile test-bed for non-equilibrium physics. This book presents an experimental investigation into exciting features arising from this non-equilibrium behavior. Through careful experimentation, the author demonstrates the ability of polaritons to synchronize and create a single energy delocalized condensate. Under certain disorder and excitation conditions the complete opposite case of coexisting spatially overlapping condensates may be observed. The author provides the first demonstration of quantized vortices in polariton condensates and the first observation of fractional vortices with full phase and amplitude characterization. Finally, this book investigate...

  15. Nanocarbon condensation in detonation

    Science.gov (United States)

    Bastea, Sorin

    2017-02-01

    We analyze the definition of the Gibbs free energy of a nanoparticle in a reactive fluid environment, and propose an approach for predicting the size of carbon nanoparticles produced by the detonation of carbon-rich explosives that regards their condensation as a nucleation process and takes into account absolute entropy effects of the cluster population. The results are consistent with experimental observations and indicate that such entropy considerations are important for determining chemical equilibrium states in energetic materials that contain an excess of carbon. The analysis may be useful for other applications that deal with the nucleation of nanoparticles under reactive conditions.

  16. Voorwoord: Professor Andrzej Borowski

    Directory of Open Access Journals (Sweden)

    Koch Jerzy

    2015-11-01

    Full Text Available Professor Andrzej Borowski from the Jagiellonian University, whose 70th anniversary we celebrate this year, is a very well known scholar and literature historian, specialised in Old Polish Literature (Middle Ages, Renaissance and Baroque - and with a background from Classical studies. A lesser known fact is that he also is a scholar active in the field of the Netherlandish (Dutch and Flemish literature and culture: as author of numerous books and articles about (South Netherlandish figures from the 16th and 17th century, as supervisor of numerous dissertations or habilitations in the field of the Netherlandish literature and as an inspiring personality in the field of the Netherlandish studies at Polish universities. He can indeed be seen as the Spiritus Litterarum Neerlandicorum in Poland.

  17. Experimental Investigation of Thermal Behaviors in Window Systems by Monitoring of Surface Condensation Using Full-Scale Measurements and Simulation Tools

    Directory of Open Access Journals (Sweden)

    Goopyo Hong

    2016-11-01

    Full Text Available The aim of the present study was to investigate the thermal performance of window systems using full-scale measurements and simulation tools. A chamber was installed on the balcony of an apartment to control the temperatures which can create condensation on the interior surfaces of window systems. The condensation process on the window was carefully scrutinized when outdoor and indoor temperature and indoor relative humidity ranged from −15 °C to −20 °C, 23 °C to 24 °C, and 50% to 65%, respectively. The results of these investigations were analyzed to determine how the moisture is influenced by changing temperatures. It appears that the glass-edge was highly susceptible to the temperature variations and the lowest temperature on the glass edge was caused by the heat transfer through the spacer, between the two glass panels of the window. The results from the simulation used in this study confirm that the thermal performance of window systems can be improved the use of super insulated or thermally broken spacers. If the values of the indoor humidity and temperature are given, then the outdoor temperature when condensation forms can be obtained by using Temperature Difference Ratio (TDR. This methodology can be employed to predict the possible occurrence of condensation.

  18. Steam condenser developments

    Science.gov (United States)

    Lang, H. V.

    Factors determining condenser size and tube arrangement are reviewed, including steam side pressure drop; incondensible blanketing; effect of incondensibles on heat transfer; vent requirements; deaeration; condensate depression; cooling water velocity; tube material and diameter selection; fouling; and enhanced heat transfer tubes. Tube nest shapes and condenser concepts are described. Thermal design, and condenser acceptance testing are treated; field test results on "Church Window'' condensers are reported.

  19. Advances in modelling of condensation phenomena

    Energy Technology Data Exchange (ETDEWEB)

    Liu, W.S.; Zaltsgendler, E. [Ontario Hydro Nuclear, Toronto (Canada); Hanna, B. [Atomic Energy of Canada Limited, Pinawa, Manitoba (Canada)

    1997-07-01

    The physical parameters in the modelling of condensation phenomena in the CANDU reactor system codes are discussed. The experimental programs used for thermal-hydraulic code validation in the Canadian nuclear industry are briefly described. The modelling of vapour generation and in particular condensation plays a key role in modelling of postulated reactor transients. The condensation models adopted in the current state-of-the-art two-fluid CANDU reactor thermal-hydraulic system codes (CATHENA and TUF) are described. As examples of the modelling challenges faced, the simulation of a cold water injection experiment by CATHENA and the simulation of a condensation induced water hammer experiment by TUF are described.

  20. Professor Igor Yevseyev: In Memoriam Professor Igor Yevseyev: In Memoriam

    Science.gov (United States)

    2012-06-01

    Dear readers and authors, June 3, 2012 will mark five months since Professor Igor Yevseyev, Deputy Editor-in-Chief of both journals Laser Physics and Laser Physics Letters passed away, suddenly and unexpectedly. He was 67. Born in Moscow, he entered one of the world's best schools of physics, Moscow Engineering Physics Institute (MEPhI). With this renowned educational and research institution he bonded an alliance for his entire life, starting as an undergraduate student in the Department of Theoretical Physics and later continued as graduate student, assistant professor, associated professor, and full professor in the same department, a rare accomplishment of a person. All those years he retained the love of his life—the love for physics. He worked tirelessly as a teacher and scholar in this captivating field of knowledge. Professor Yevseyev was one of the founders of the international journal of Laser Physics in 1990, the first academic English language journal published in the former USSR. Later, in 2004, the second journal, Laser Physics Letters was brought to the forum of global laser physics community. The idea behind this new title was Professor Yevseyev's initiative to reach the readers and participants with new pioneering and break-through research results more rapidly. His leadership and indefatigable dedication to the quality of published materials made it possible that this journal reached international recognition in a few short years. Still, in order to attract even more attention of potential contributors and readers, Professor Yevseyev originally proposed to conduct the International Laser Physics Workshop (LPHYS) on the annual basis. Since 1992 the Workshop has been conducted every year, each year in a different country. As in all previous years, Professor Yevseyev was the key organizer of this year's workshop in Calgary, Canada. Sadly, this workshop will take place without him. Editorial Board

  1. Memorial to Professor Antonio Barone

    Science.gov (United States)

    Tafuri, Francesco; Pepe, Giampiero; Vaglio, Ruggero

    2014-04-01

    Antonio Barone prematurely passed away on 4 December 2011 at the age of 72, after a one-year battle with cancer. He left behind his wife Sveva and his two sons, Alberto and Livio. Antonio was Professor Emeritus at the University of Napoli Federico II, where he had been teaching for about 40 years. The initial research activity of Antonio was in the field of nuclear physics. In this context, almost 45 years ago, the Ge 'Lithium drift' semiconductor detectors represented a novelty, due to the high energy resolution enabled by those devices. Superconductors stimulated new approaches to radiation detection and this motivated Antonio's interest towards superconductivity. Following the birth of the Laboratorio di Cibernetica of the CNR in 1967 he was given the opportunity to work on a joint USA-Italy project (University of Wisconsin, Madison and CNR Naples) in the field of superconductivity on the peculiar subject of the superconductive 'Neuristors'. His research activity on Josephson junctions opened up a wide variety of very stimulating subjects in which he was deeply involved, ranging from the soliton propagation in 'long' Josephson structures to fluctuations phenomena, from light-sensitive junctions and proximity effect to the development of innovative superconducting devices. The strong interaction of Antonio with the Landau Institute for Theoretical Physics of the Academy of Sciences in Moscow, characterizes a long period of his research activity with a precious merging of theoretical and experimental aspects. This body of work converged into the famous monograph on the 'Physics and Applications of the Josephson Effect', written in collaboration with Gianfranco Paternò in 1982. This rapidly became the reference text for the Josephson effect, as documented by thousands of citations and the fact that it was translated into Russian, Japanese and Chinese. In 1983 Antonio was awarded the highest academic title of 'Doctor of the Physical-Mathematical Sciences' by the

  2. The Profession and the Professors.

    Science.gov (United States)

    Dain, Phyllis

    1980-01-01

    Speculates on why graduate library schools have not, in the persons of their professors, produced theoretical leadership in Library Science. The ideals of professional ethical standards are contrasted with present practice. (RAA)

  3. Response to Professor Jean Guichard

    OpenAIRE

    Kargulowa, Alicja; Czerkawska, Alicja; Kłodkowska, Joanna; Siarkiewicz, Elżbieta; Zielińska-Pękał, Daria; Zierkiewicz, Edyta

    2013-01-01

    The article recounts a discussion inspired by Professor Jean Guichard’s letter to Professor Alicja Kargulowa. Its participants – a group of female counsellogists – are engaged in an e-mail exchange that freely unfolds in the symbolic space of the on-line discourse. Embedded in their own specific research, their contributions depart from a conventional, structured line of argumentation, spontaneously, and at the same time insightfully, reflecting on various facets of purification and translati...

  4. Soft Condensed Matter

    Energy Technology Data Exchange (ETDEWEB)

    Jones, Richard A L

    2002-11-20

    phenomenologically and formulated through the current percolation model and the Flory-Stockmayer model. The next two chapters consider the molecular order in soft condensed matter. The rich complexity of liquid crystals is emphasized and the Frederiks transition is described in relation to liquid crystal displays. The crystallinity in polymers is discussed and its usual semi-crystallinity presented as a consequence of entanglement and timescales. The next chapter describes the self-assembly of phases and the great importance of the self-assembly phenomenon in solutions of amphiphilic molecules is largely discussed in several specific phenomena. The book ends with a chapter devoted to the description of soft matter realizations in nature. Special attention is paid to the components and structure of life: nucleic acids, proteins, polysaccharides and membranes. There are two appendixes recalling the basic concepts of thermodynamics and statistical mechanics. In each chapter, several problems are included, and solutions to a selection of them are given. The bibliography proposed is pertinent and each chapter gives details of further reading, mostly addressed to known books on the topic. The presentation of the book is good. Throughout the book, the relevant, basic or new concepts of each topic are typed in bold characters and succinctly defined. The figures are abundant and adequately illustrate the text either by plots of experimental data or by computed predictions from models. Many schematic representations of structures, molecular distributions or arrangements are also included. In summary, the author has succeeded in producing a scientifically rigorous book of affordable size (around 200 pages) that is well illustrated (about 120 figures) and written in a fluent style that describes the many different physical phenomena involved in soft condensed matter. (book review)

  5. Condensed Matter Nuclear Science

    Science.gov (United States)

    Biberian, Jean-Paul

    2006-02-01

    into characteristics of X-ray emission laser beams from solidstate cathode medium of high-current glow discharge / A. B. Karabut. Charged particles from Ti and Pd foils / L. Kowalski ... [et al.]. Cr-39 track detectors in cold fusion experiments: review and perspectives / A. S. Roussetski. Energetic particle shower in the vapor from electrolysis / R. A. Oriani and J. C. Fisher. Nuclear reactions produced in an operating electrolysis cell / R. A. Oriani and J. C. Fisher. Evidence of microscopic ball lightning in cold fusion experiments / E. H. Lewis. Neutron emission from D[symbol] gas in magnetic fields under low temperature / T. Mizuno ... [et al.]. Energetic charged particle emission from hydrogen-loaded Pd and Ti cathodes and its enhancement by He-4 implantation / A. G. Lipson ... [et al.]. H-D permeation. Observation of nuclear transmutation reactions induced by D[symbol] gas permeation through Pd complexes / Y. Iwamura ... [et al.]. Deuterium (hydrogen) flux permeating through palladium and condensed matter nuclear science / Q. M. Wei ... [et al.]. Triggering. Precursors and the fusion reactions in polarized Pd/D-D[symbol]O system: effect of an external electric field / S. Szpak, P. A. Mosier-Boss, and F. E. Gordon. Calorimetric and neutron diagnostics of liquids during laser irradiation / Yu. N. Bazhutov ... [et al.]. Anomalous neutron capture and plastic deformation of Cu and Pd cathodes during electrolysis in a weak thermalized neutron field: evidence of nuclei-lattice exchange / A. G. Lipson and G. H. Miley. H-D loading. An overview of experimental studies on H/Pd over-loading with thin Pd wires and different electrolytic solutions / A. Spallone ... [et al.] -- 3. Transmutations. Photon and particle emission, heat production, and surface transformation in Ni-H system / E. Campari ... [et al.]. Surface analysis of hydrogen-loaded nickel alloys / E. Campari ... [et al.]. Low-energy nuclear reactions and the leptonic monopole / G. Lochak and L. Urutskoev. Results

  6. Professor Peter Higgs: "My Life as a Boson"

    CERN Multimedia

    CERN. Geneva

    2012-01-01

    Professor Peter Higgs played a key role in the development of the Standard Model, our current theory of fundamental physics. The search for the Higgs Boson is the centrepiece of the LHC programme at CERN, and the existence of this famously elusive particle is likely to be confirmed or refuted with data currently being collected, using apparatus partly designed at Bristol. Professor Higgs will introduce the ideas of spontaneous symmetry breaking, and discuss how these developed from their application in condensed matter through the earlier work of Yoichiro Nambu and Jeffrey Goldstone, to the work of Robert Brout, Francois Englert and himself in 1964. The subsequent application of these ideas to electroweak theory will be discussed briefly.

  7. Condensation in insulated homes

    Energy Technology Data Exchange (ETDEWEB)

    Wiley, R A

    1978-05-28

    A research proposal on condensation in insulated homes is presented. Information is provided on: justification for condensation control; previous work and present outlook (good vapor barrier, condensation and retrofit insulation, vapor barrier decreases condensation, brick-veneer walls, condensation in stress-skin panels, air-conditioned buildings, retrofitting for conservation, study on mobile homes, high indoor relative humidity, report on various homes); and procedure (after funding has been secured). Measures are briefly described on opening walls, testing measures, and retrofitting procedures. An extensive bibliography and additional informative citations are included. (MCW)

  8. Capillary Condensation in 8 nm Deep Channels.

    Science.gov (United States)

    Zhong, Junjie; Riordon, Jason; Zandavi, Seyed Hadi; Xu, Yi; Persad, Aaron H; Mostowfi, Farshid; Sinton, David

    2018-02-01

    Condensation on the nanoscale is essential to understand many natural and synthetic systems relevant to water, air, and energy. Despite its importance, the underlying physics of condensation initiation and propagation remain largely unknown at sub-10 nm, mainly due to the challenges of controlling and probing such small systems. Here we study the condensation of n-propane down to 8 nm confinement in a nanofluidic system, distinct from previous studies at ∼100 nm. The condensation initiates significantly earlier in the 8 nm channels, and it initiates from the entrance, in contrast to channels just 10 times larger. The condensate propagation is observed to be governed by two liquid-vapor interfaces with an interplay between film and bridging effects. We model the experimental results using classical theories and find good agreement, demonstrating that this 8 nm nonpolar fluid system can be treated as a continuum from a thermodynamic perspective, despite having only 10-20 molecular layers.

  9. Condensation of the air-steam mixture in a vertical tube condenser

    Directory of Open Access Journals (Sweden)

    Havlík Jan

    2016-01-01

    Full Text Available This paper deals with the condensation of water vapour in the presence of non-condensable air. Experimental and theoretical solutions of this problem are presented here. A heat exchanger for the condensation of industrial waste steam containing infiltrated air was designed. The condenser consists of a bundle of vertical tubes in which the steam condenses as it flows downwards with cooling water flowing outside the tubes in the opposite direction. Experiments with pure steam and with mixtures of steam with added air were carried out to find the dependence of the condensation heat transfer coefficient (HTC on the air concentration in the steam mixture. The experimental results were compared with the theoretical formulas describing the cases. The theoretical determination of the HTC is based on the Nusselt model of steam condensation on a vertical wall, where the analogy of heat and mass transfer is used to take into account the behaviour of air in a steam mixture during the condensation process. The resulting dependencies obtained from the experiments and obtained from the theoretical model have similar results. The significant decrease in the condensation HTC, which begins at very low air concentrations in a steam mixture, was confirmed.

  10. Il professor Mitja Skubic ottuagenario

    Directory of Open Access Journals (Sweden)

    Martina Ožbot

    2008-12-01

    Full Text Available Incredibile ma vero: il professor Mitja Skubic si trova, questa volta lui stesso, al centro dell’attenzione anziché essere il motore, il perno dell’attività. La ragione per questo attimo di respiro è il suo ottantesimo compleanno, a dire il vero passato già da tempo. È pressoché una contingenza aneddotica quella per cui il volume dedicatogli per l’occasione viene pubblicato così tardi: il professore ha continuato a tener d’occhio la nostra rivista ben dopo aver nominato i nuovi direttori tanto che sarebbe stato impossibile sorprenderlo con una miscellanea di contributi in suo onore.

  11. Professor@s e Eros Teachers and Eros

    Directory of Open Access Journals (Sweden)

    Deborah P. Britzman

    2009-01-01

    Full Text Available Professores/as são testemunhas do fantástico mundo da sexualidade. Esse artigo explora a centralidade de Eros para a educação e estabelece uma relação entre o desejo do/a professor/a e os acontecimentos emocionais da relação própria relação aluno/professor. Eu proponho que o aprendizado deva envolver nosso "eu" erótico, além das nossas fantasias. Mas esta perspectiva requer que professores/as considerem uma psicologia do amor como um caminho principal para a as situações emocionais de Eros. Na sua conclusão este trabalho sugere uma pedagogia que dê as boas vindas tanto à homossexualidade como a heterossexualidade como expressões humanas do amor.Teachers bear witness to the wondrous world of sexuality. This essay explores the centrality of Eros to education and links the teacher's desire to the emotional situation of the student/teacher relationship. I propose that learning involves our erotic selves and our fantasy life. But such a view requires that teachers consider a psychology of love as lending insight into the emotional situation of Eros. The paper concludes by suggesting a pedagogy that welcomes homosexuality and heterosexuality as human expressions of love.

  12. Advances in condensed matter optics

    CERN Document Server

    Chen, Liangyao; Jiang, Xunya; Jin, Kuijuan; Liu, Hui; Zhao, Haibin

    2015-01-01

    This book describes some of the more recent progresses and developmentsin the study of condensed matter optics in both theoretic and experimental fields.It will help readers, especially graduate students and scientists who are studying and working in the nano-photonic field, to understand more deeply the characteristics of light waves propagated in nano-structure-based materials with potential applications in the future.

  13. Student teachers can be as good as associate professors in teaching clinical skills

    DEFF Research Database (Denmark)

    Tolsgaard, Martin G; Gustafsson, Amandus; Rasmussen, Maria B

    2007-01-01

    AIM: The aim of this study is to compare student teachers and clinical associate professors regarding the quality of procedural skills teaching in terms of participants' technical skills, knowledge and satisfaction with the teaching. METHODS: This is an experimental, randomized, controlled study ....... CONCLUSION: Trained student teachers can be as good as associate professors in teaching clinical skills. Udgivelsesdato: 2007-Sep...

  14. Measurement of liquid-liquid equilibria for condensate + glycol and condensate + glycol + water systems

    DEFF Research Database (Denmark)

    Riaz, Muhammad; Kontogeorgis, Georgios; Stenby, Erling Halfdan

    2011-01-01

    Today's oil and gas production requires the application of various chemicals in large amounts. To evaluate the effects of those chemicals on the environment, it is of crucial importance to know how much of the chemicals are discharged via produced water and how much is dissolved in the crude oil....... The ultimate objective of this work is to develop a predictive thermodynamic model for the mutual solubility of oil, water, and polar chemicals. But for the development and validation of the model, experimental data are required. This work presents new experimental liquid-liquid equilibrium (LLE) data for 1......,2-ethanediol (MEG) + condensate and MEG + water + condensate systems at temperatures from (275 to 323) K at atmospheric pressure. The condensate used in this work is a stabilized natural gas condensate from an offshore field in the North Sea. Compositional analysis of the natural gas condensate was carried out...

  15. Does Gender and Professional Experience Influence Students' Perceptions of Professors?

    Science.gov (United States)

    Tindall, Natalie T. J.; Waters, Richard D.

    2017-01-01

    Grounded in literature stemming from higher education research, this study examines how students evaluate public relations educators by gauging their perceptions of the professors' professional competency, professorial warmth, course difficulty, and industry connectivity. Using an experimental design, students (N = 303) from four U.S. universities…

  16. Professors of the New Economy.

    Science.gov (United States)

    Wilson, Robin

    2000-01-01

    Profiles four professors who epitomize the increasing influence of academe on new technology-driven Internet business: a start-up maven, Steven Kaplan; a social psychologist, Michael Ray; a cyberlawyer, David Post; and an e-commerce expert, Andrew B. Whinston. (DB)

  17. Vortices and turbulence in trapped atomic condensates

    Science.gov (United States)

    White, Angela C.; Anderson, Brian P.; Bagnato, Vanderlei S.

    2014-01-01

    After more than a decade of experiments generating and studying the physics of quantized vortices in atomic gas Bose–Einstein condensates, research is beginning to focus on the roles of vortices in quantum turbulence, as well as other measures of quantum turbulence in atomic condensates. Such research directions have the potential to uncover new insights into quantum turbulence, vortices, and superfluidity and also explore the similarities and differences between quantum and classical turbulence in entirely new settings. Here we present a critical assessment of theoretical and experimental studies in this emerging field of quantum turbulence in atomic condensates. PMID:24704880

  18. NOTES ON CONTRIBUTORS H. Johnson Nenty, Professor ...

    African Journals Online (AJOL)

    Admin

    NOTES ON CONTRIBUTORS. H. Johnson Nenty, Professor, Educational Research, Measurement and Evaluation, Department of Educational. Foundations, University of Botswana Idowu Biao, Professor of Lifelong learning, Department of Adult Education,. University of Botswana. Cletus K. Mbowura, Lecturer, Department of ...

  19. Modeling of Kerena Emergency Condenser

    Directory of Open Access Journals (Sweden)

    Bryk Rafał

    2017-12-01

    Full Text Available KERENA is an innovative boiling water reactor concept equipped with several passive safety systems. For the experimental verification of performance of the systems and for codes validation, the Integral Test Stand Karlstein (INKA was built in Karlstein, Germany. The emergency condenser (EC system transfers heat from the reactor pressure vessel (RPV to the core flooding pool in case of water level decrease in the RPV. EC is composed of a large number of slightly inclined tubes. During accident conditions, steam enters into the tubes and condenses due to the contact of the tubes with cold water at the secondary side. The condensed water flows then back to the RPV due to gravity. In this paper two approaches for modeling of condensation in slightly inclined tubes are compared and verified against experiments. The first approach is based on the flow regime map. Depending on the regime, heat transfer coefficient is calculated according to specific semi-empirical correlation. The second approach uses a general, fully-empirical correlation. The models are developed with utilization of the object-oriented Modelica language and the open-source OpenModelica environment. The results are compared with data obtained during a large scale integral test, simulating loss of coolant accident performed at Integral Test Stand Karlstein (INKA. The comparison shows a good agreement.Due to the modularity of models, both of them may be used in the future in systems incorporating condensation in horizontal or slightly inclined tubes. Depending on his preferences, the modeller may choose one-equation based approach or more sophisticated model composed of several exchangeable semi-empirical correlations.

  20. Modeling of Kerena Emergency Condenser

    Science.gov (United States)

    Bryk, Rafał; Schmidt, Holger; Mull, Thomas; Wagner, Thomas; Ganzmann, Ingo; Herbst, Oliver

    2017-12-01

    KERENA is an innovative boiling water reactor concept equipped with several passive safety systems. For the experimental verification of performance of the systems and for codes validation, the Integral Test Stand Karlstein (INKA) was built in Karlstein, Germany. The emergency condenser (EC) system transfers heat from the reactor pressure vessel (RPV) to the core flooding pool in case of water level decrease in the RPV. EC is composed of a large number of slightly inclined tubes. During accident conditions, steam enters into the tubes and condenses due to the contact of the tubes with cold water at the secondary side. The condensed water flows then back to the RPV due to gravity. In this paper two approaches for modeling of condensation in slightly inclined tubes are compared and verified against experiments. The first approach is based on the flow regime map. Depending on the regime, heat transfer coefficient is calculated according to specific semi-empirical correlation. The second approach uses a general, fully-empirical correlation. The models are developed with utilization of the object-oriented Modelica language and the open-source OpenModelica environment. The results are compared with data obtained during a large scale integral test, simulating loss of coolant accident performed at Integral Test Stand Karlstein (INKA). The comparison shows a good agreement.Due to the modularity of models, both of them may be used in the future in systems incorporating condensation in horizontal or slightly inclined tubes. Depending on his preferences, the modeller may choose one-equation based approach or more sophisticated model composed of several exchangeable semi-empirical correlations.

  1. ICT Use by Journalism Professors in Colombia

    Science.gov (United States)

    Hung, Elias Said

    2011-01-01

    This article analyses how journalism professors at Colombian universities use information and communications technologies (ICT) in their teaching. Survey data was obtained during the first trimester of 2009 from 63 professors in journalism departments and from a total of 865 professors who are affiliated with journalism departments at 29…

  2. Erratum: Professor J. H. S. Gear

    African Journals Online (AJOL)

    s short of their. Lesley, a nd their amily a proper Wake on 15 November 1994. Erratum: Professor J. H. S. Gear. The name of Professor B. D. Schoub, Director of the. National Institute for Virology, was inadvertently omitted as the author of the obituary of Professor J. H. S. Gear published in the September 1994 SAMJ. Books.

  3. Fundamentals of condensed matter physics

    CERN Document Server

    Cohen, Marvin L

    2016-01-01

    Based on an established course and covering the fundamentals, central areas, and contemporary topics of this diverse field, Fundamentals of Condensed Matter Physics is a much-needed textbook for graduate students. The book begins with an introduction to the modern conceptual models of a solid from the points of view of interacting atoms and elementary excitations. It then provides students with a thorough grounding in electronic structure as a starting point to understand many properties of condensed matter systems - electronic, structural, vibrational, thermal, optical, transport, magnetic and superconductivity - and methods to calculate them. Taking readers through the concepts and techniques, the text gives both theoretically and experimentally inclined students the knowledge needed for research and teaching careers in this field. It features 200 illustrations, 40 worked examples and 150 homework problems for students to test their understanding. Solutions to the problems for instructors are available at w...

  4. Systematic text condensation

    DEFF Research Database (Denmark)

    Malterud, Kirsti

    2012-01-01

    To present background, principles, and procedures for a strategy for qualitative analysis called systematic text condensation and discuss this approach compared with related strategies.......To present background, principles, and procedures for a strategy for qualitative analysis called systematic text condensation and discuss this approach compared with related strategies....

  5. Measure Guideline: Evaporative Condensers

    Energy Technology Data Exchange (ETDEWEB)

    German, A [Alliance for Residential Building Innovation (ARBI), Davis, CA (United States); Dakin, B. [Alliance for Residential Building Innovation (ARBI), Davis, CA (United States); Hoeschele, M. [Alliance for Residential Building Innovation (ARBI), Davis, CA (United States)

    2012-03-01

    This measure guideline on evaporative condensers provides information on properly designing, installing, and maintaining evaporative condenser systems as well as understanding the benefits, costs, and tradeoffs. This is a prescriptive approach that outlines selection criteria, design and installation procedures, and operation and maintenance best practices.

  6. Freeze-Tolerant Condensers

    Science.gov (United States)

    Crowley, Christopher J.; Elkouhk, Nabil

    2004-01-01

    Two condensers designed for use in dissipating heat carried by working fluids feature two-phase, self-adjusting configurations such that their working lengths automatically vary to suit their input power levels and/or heat-sink temperatures. A key advantage of these condensers is that they can function even if the temperatures of their heat sinks fall below the freezing temperatures of their working fluids and the fluids freeze. The condensers can even be restarted from the frozen condition. The top part of the figure depicts the layout of the first condenser. A two-phase (liquid and vapor) condenser/vapor tube is thermally connected to a heat sink typically, a radiatively or convectively cooled metal panel. A single-phase (liquid) condensate-return tube (return artery) is also thermally connected to the heat sink. At intervals along their lengths, the condenser/vapor tube and the return artery are interconnected through porous plugs. This condenser configuration affords tolerance of freezing, variable effective thermal conductance (such that the return temperature remains nearly constant, independently of the ultimate sink temperature), and overall pressure drop smaller than it would be without the porous interconnections. An additional benefit of this configuration is that the condenser can be made to recover from the completely frozen condition either without using heaters, or else with the help of heaters much smaller than would otherwise be needed. The second condenser affords the same advantages and is based on a similar principle, but it has a different configuration that affords improved flow of working fluid, simplified construction, reduced weight, and faster recovery from a frozen condition.

  7. Honorary issue dedicated to the 70-th anniversary of Professor Ihor Stasyuk

    Directory of Open Access Journals (Sweden)

    Editorial Board

    2008-09-01

    Full Text Available On September 23, 2008 Professor Ihor Stasyuk, a prominent Ukrainian scientist, celebrates his 70th birthday. On this occasion, Institute for Condensed Matter Physics of the National Academy of Sciences of Ukraine and Editorial Board of "Condensed Matter Physics" decided to honour him with a collection of scientific papers. With great pleasure have numerous researchers, colleagues and coworkers of Prof. Stasyuk contributed their articles. The Editorial Board of "Condensed Matter Physics" expresses sincere gratitude to all of them. The highly skilled contributions deal with statistical theory of condensed matter, strongly correlated electron and spin systems, ferroelectrics and other areas which are close to the jubileer's interests during almost 50 years of his scientific activities.

  8. The Dynamics of Aerosols in Condensational Scrubbers

    DEFF Research Database (Denmark)

    Johannessen, Jens Tue; Christensen, Jan A.; Simonsen, Ole

    1997-01-01

    A mathematical model for the simulation of the dynamics of aerosol change in condensational scrubbers and scrubbing condensers is proposed. The model is applicable for packed column gas/liquid contact when plug flow can be assumed. The model is compared with experimental data for particle removal...... in a pilot plant condensational scrubber. The model can satisfactorily predict particle growth and particle deposition by diffusional, convective and inertial mechanisms for a wide range of conditions. The parameters of principal importance for the model precision are identified and a procedure...... for their estimation is proposed. The behaviour of scrubbers and condensers for some important technical applications is demonstrated by model simulations. (C) 1997 Elsevier Science Ltd....

  9. Experimental Investigations Of The Influence Of Pressure On Critical Extinction Conditions Of Laminar Nonpremixed Flames Burning Condensed Hydrocarbon Fuels, Jet Fuels, And Surrogates

    Science.gov (United States)

    2014-10-25

    model combustion of practical fuels at high pressures. Commercial fuels, including jet fuels, kerosene, gasoline, and diesel , are composed of hundreds...the experimental testing of fuels with high boiling points for which it is difficult to avoid pyrolysis reactions during fuel vaporization [22]. Figure...flame as well as stabi- lize it. Product gases are cooled using fine water sprays within the burner body, then separated from the cooling water in a

  10. Quantification of chromatin condensation level by image processing.

    Science.gov (United States)

    Irianto, Jerome; Lee, David A; Knight, Martin M

    2014-03-01

    The level of chromatin condensation is related to the silencing/activation of chromosomal territories and therefore impacts on gene expression. Chromatin condensation changes during cell cycle, progression and differentiation, and is influenced by various physicochemical and epigenetic factors. This study describes a validated experimental technique to quantify chromatin condensation. A novel image processing procedure is developed using Sobel edge detection to quantify the level of chromatin condensation from nuclei images taken by confocal microscopy. The algorithm was developed in MATLAB and used to quantify different levels of chromatin condensation in chondrocyte nuclei achieved through alteration in osmotic pressure. The resulting chromatin condensation parameter (CCP) is in good agreement with independent multi-observer qualitative visual assessment. This image processing technique thereby provides a validated unbiased parameter for rapid and highly reproducible quantification of the level of chromatin condensation. Copyright © 2013 IPEM. Published by Elsevier Ltd. All rights reserved.

  11. Physics of condensed matter

    CERN Document Server

    Misra, Prasanta K

    2012-01-01

    Physics of Condensed Matter is designed for a two-semester graduate course on condensed matter physics for students in physics and materials science. While the book offers fundamental ideas and topic areas of condensed matter physics, it also includes many recent topics of interest on which graduate students may choose to do further research. The text can also be used as a one-semester course for advanced undergraduate majors in physics, materials science, solid state chemistry, and electrical engineering, because it offers a breadth of topics applicable to these majors. The book be

  12. Theory of laminar film condensation

    CERN Document Server

    Fujii, Tetsu

    1991-01-01

    Since the petroleum crisis in the 1970s, a lot of effort to save energy was made in industry, and remarkable achievements have been made. In the research and development concerning thermal energy, however, it was clar­ ified that one of the most important problems was manufacturing con­ densing systems with smaller size and higher performance. To solve this problem we need a method which synthesizes selections_ of the type of con­ denser, cooling tube and its arrangement, assessment of fouling on the cooling surfaces, consideration of transient characteristics of a condenser, etc. The majority of effort, however, has been to devise a surface element which enhances the heat transfer coefficient in condensation of a single or multicomponent vapor. Condensation phenomena are complexly affected by a lot of physical property values, and accordingly the results of theo­ retical research are expressed with several dimensionless parameters. On the other hand, the experimental research is limited to those with som...

  13. Condensation of HFE-7100 vapor in a loop heat pipe having a curvilinear fin

    Directory of Open Access Journals (Sweden)

    Lyulin Yuriy

    2017-01-01

    Full Text Available Vapor condensation of the HFE-7100 in loop heat pipe was studied experimentally and theoretically. Numerical calculations of the vapor condensation on the curvilinear fin have been performed. Numerical, theoretical and experimental data are in a good agreement. Minimal condensate film thickness on the top of the fin has been determined and increases monotonously with the increase in the temperature drop.

  14. Measure Guideline: Evaporative Condensers

    Energy Technology Data Exchange (ETDEWEB)

    German, A.; Dakin, B.; Hoeschele, M.

    2012-03-01

    The purpose of this measure guideline on evaporative condensers is to provide information on a cost-effective solution for energy and demand savings in homes with cooling loads. This is a prescriptive approach that outlines selection criteria, design and installation procedures, and operation and maintenance best practices. This document has been prepared to provide a process for properly designing, installing, and maintaining evaporative condenser systems as well as understanding the benefits, costs, and tradeoffs.

  15. 19 January 2011 - British University of Manchester, Vice-President and Dean for the Faculty of Engineering and Physical Sciences Professor of Structural Engineering School of Mechanical, Aerospace and Civil Engineering C. Bailey in CERN Control Centre with Department Head P. Collier; at LHCb with R. Lindner and ATLAS underground experimental area with Deputy Spokesperson D. Charlton, througout accompanied by . Collier with R. Appleby and F. Loebinger

    CERN Multimedia

    Maximilien Brice

    2011-01-01

    19 January 2011 - British University of Manchester, Vice-President and Dean for the Faculty of Engineering and Physical Sciences Professor of Structural Engineering School of Mechanical, Aerospace and Civil Engineering C. Bailey in CERN Control Centre with Department Head P. Collier; at LHCb with R. Lindner and ATLAS underground experimental area with Deputy Spokesperson D. Charlton, througout accompanied by . Collier with R. Appleby and F. Loebinger

  16. Assessment and improvement of condensation model in RELAP5/MOD3

    Energy Technology Data Exchange (ETDEWEB)

    Rho, Hui Cheon; Choi, Kee Yong; Park, Hyeon Sik; Kim, Sang Jae [Korea Advanced Institute of Science and Technology, Taejon (Korea, Republic of); Lee, Sang Il [Korea Power Engineering Co., Inc., Seoul (Korea, Republic of)

    1997-07-15

    The objective of this research is to remove the uncertainty of the condensation model through the assessment and improvement of the various heat transfer correlations used in the RELAP5/MOD3 code. The condensation model of the standard RELAP5/MOD3 code is systematically arranged and analyzed. A condensation heat transfer database is constructed from the previous experimental data on various condensation phenomena. Based on the constructed database, the condensation models in the code are assessed and improved. An experiment on the reflux condensation in a tube of steam generator in the presence of noncondensable gases is planned to acquire the experimental data.

  17. Interview with Professor Mark Wilcox.

    Science.gov (United States)

    Wilcox, Mark

    2016-08-01

    Mark Wilcox speaks to Georgia Patey, Commissioning Editor: Professor Mark Wilcox is a Consultant Microbiologist and Head of Microbiology at the Leeds Teaching Hospitals (Leeds, UK), the Professor of Medical Microbiology at the University of Leeds (Leeds, UK), and is the Lead on Clostridium difficile and the Head of the UK C. difficile Reference Laboratory for Public Health England (PHE). He was the Director of Infection Prevention (4 years), Infection Control Doctor (8 years) and Clinical Director of Pathology (6 years) at the Leeds Teaching Hospitals. He is Chair of PHE's Rapid Review Panel (reviews utility of infection prevention and control products for National Health Service), Deputy Chair of the UK Department of Health's Antimicrobial Resistance and Healthcare Associated Infection Committee and a member of PHE's HCAI/AR Programme Board. He is a member of UK/European/US working groups on C. difficile infection. He has provided clinical advice as part of the FDA/EMA submissions for the approval of multiple novel antimicrobial agents. He heads a healthcare-associated infection research team at University of Leeds, comprising approximately 30 doctors, scientists and nurses; projects include multiple aspects of C. difficile infection, diagnostics, antimicrobial resistance and the clinical development of new antimicrobial agents. He has authored more than 400 publications, and is the coeditor of Antimicrobial Chemotherapy (5th/6th/7th Editions, 15 December 2007).

  18. Numerical study of bulk condensation in laminar flow diffusion chamber

    Science.gov (United States)

    Mayorov, V. O.; Yastrebov, A. K.

    2017-11-01

    The process of bulk condensation was studied on a basis numerical solution of kinetic equation for the mass distribution function of droplet size and the equations of mass and energy balance. The effect of the condenser and preheater deference temperature was studied. Obtained results were compared with other authors’ experimental and numerical data qualitatively and quantitatively.

  19. Resonant tunneling of Bose-Einstein condensates in optical lattices

    Energy Technology Data Exchange (ETDEWEB)

    Zenesini, Alessandro; Sias, Carlo; Lignier, Hans; Singh, Yeshpal; Ciampini, Donatella; Morsch, Oliver; Mannella, Riccardo; Arimondo, Ennio [Dipartimento di Fisica Enrico Fermi, Universita degli Studi di Pisa, Largo Pontecorvo 3, I-56127 Pisa (Italy); Tomadin, Andrea [Scuola Normale Superiore, Piazza dei Cavalieri 7, I-56126 Pisa (Italy); Wimberger, Sandro [Institut fuer Theoretische Physik, Universitaet Heidelberg, Philosophenweg 19, D-69120 Heidelberg (Germany)], E-mail: s.wimberger@thphys.uni-heidelberg.de

    2008-05-15

    In this paper, we present the theoretical as well as experimental results on resonantly enhanced tunneling of Bose-Einstein condensates in optical lattices both in the linear case and for small nonlinearities. Our results demonstrate the usefulness of condensates in optical lattices for simulating Hamiltonians originally used for describing solid-state phenomena.

  20. Resonant tunneling of Bose-Einstein condensates in optical lattices

    OpenAIRE

    Zenesini, Alessandro; Sias, Carlo; Lignier, Hans; Singh, Yeshpal; Ciampini, Donatella; Morsch, Oliver; Mannella, Riccardo; Arimondo, Ennio; Tomadin, Andrea; Wimberger, Sandro

    2007-01-01

    In this article, we present theoretical as well as experimental results on resonantly enhanced tunneling of Bose-Einstein condensates in optical lattices both in the linear case and for small nonlinearities. Our results demonstrate the usefulness of condensates in optical lattices for simulating Hamiltonians originally used for describing solid state phenomena.

  1. Professor Gender, Age, and "Hotness" in Influencing College Students' Generation and Interpretation of Professor Ratings

    Science.gov (United States)

    Sohr-Preston, Sara L.; Boswell, Stefanie S.; McCaleb, Kayla; Robertson, Deanna

    2016-01-01

    A sample of 230 undergraduate psychology students rated their expectations of a bogus professor (who was randomly designated a man or woman and "hot" versus "not hot") based on ratings and comments found on RateMyProfessors.com. Five professor qualities were derived using principal components analysis: dedication,…

  2. Molecular attraction of condensed bodies

    Science.gov (United States)

    Derjaguin, B. V.; Abrikosova, I. I.; Lifshitz, E. M.

    2015-09-01

    From the Editorial Board. As a contribution to commemorating the 100th anniversary of the birth of Evgenii Mikhailovich Lifshitz, it was found appropriate by the Editorial Board of Uspekhi Fizicheskikh Nauk (UFN) [Physics-Uspekhi] journal that the materials of the jubilee-associated Scientific Session of the Physical Sciences Division of the Russian Academy of Sciences published in this issue (pp. 877-905) be augmented by the review paper "Molecular attraction of condensed bodies" reproduced from a 1958 UFN issue. Included in this review, in addition to an account by Evgenii Mikhailovich Lifshitz of his theory of molecular attractive forces between condensed bodies (first published in Zhurnal Eksperimental'noi i Teoreticheskoi Fiziki (ZhETF) in 1955 and in its English translation Journal of Experimental and Theoretical Physics (JETP) in 1956), is a summary of a series of experimental studies beginning in 1949 by Irina Igorevna Abrikosova at the Institute of Physical Chemistry of the Academy of Sciences of the USSR in a laboratory led by Boris Vladimirovich Derjaguin (1902-1994), a Corresponding Member of the USSR Academy of Sciences. In 1958, however, UFN was not yet available in English translation, so the material of the review is insufficiently accessible to the present-day English-speaking reader. This is the reason why the UFN Editorial Board decided to contribute to celebrating the 100th anniversary of E M Lifshitz's birthday by reproducing on the journal's pages a 1958 review paper which contains both E M Lifshitz's theory itself and the experimental data that underpinned it (for an account of how Evgenii Mikhailovich Lifshitz was enlisted to explain the experimental results of I I Abrikosova and B V Derjaguin, see the letter to the editors N P Danilova on page 925 of this jubilee collection of publications).

  3. 'Supermentoring' of assistant professors' teaching

    DEFF Research Database (Denmark)

    Lauridsen, Ole

    Aarhus University offers a mandatory pedagogical training program for assistant professors, required in order to obtain tenure at a Danish university. At Business and Social Sciences, this program is supplemented by voluntary observation and (first of all formative) supervision of the assistant...... professors’ teaching practice. This offer is given is (i) because many young university teachers face problems putting pedagogical theory into practice – even though the program mentioned is practice-oriented, and (ii) because many of them (partly due to (i)) lack self-confidence as to teaching....... The presentation will discuss the theoretical framework of the supervision given and compare it to other supervision models. Furthermore it will address the need of working with supervision in a SOTL context. Attendees will be activated through discussion of short prototypical cases. A possible – and desired...

  4. Observations on Professor Hayek's Plan

    Directory of Open Access Journals (Sweden)

    Ludwig von Mises

    2009-01-01

    Full Text Available This memorandum was written at the request of Henry Hazlitt to provide Mises’s comments on and concerns about F.A. Hayek’s initial proposals for what became the Mont Pèlerin Society. Mises stresses that those who favor liberty and freedom and oppose totalitarianism must also oppose interventionism. The memo argues that those who fought and lost against the rising tide of totalitarianism at the turn of the 20th Century lost their battles because they settled for middle-of-the-road policies that conceded considerable ground to the socialists. The weak point in Professor Hayek’s plan is that it relies upon the cooperation of many men who are today’s middle-of-the-roaders. As interventionists, they may not be the hoped-for intellectual pioneers to inspire people to build a freer world.

  5. Professor Camillo Negro's Neuropathological Films.

    Science.gov (United States)

    Chiò, Adriano; Gianetto, Claudia; Dagna, Stella

    2016-01-01

    Camillo Negro, Professor in Neurology at the University of Torino, was a pioneer of scientific film. From 1906 to 1908, with the help of his assistant Giuseppe Roasenda and in collaboration with Roberto Omegna, one of the most experienced cinematographers in Italy, he filmed some of his patients for scientific and educational purposes. During the war years, he continued his scientific film project at the Military Hospital in Torino, filming shell-shocked soldiers. In autumn 2011, the Museo Nazionale del Cinema, in partnership with the Faculty of Neurosciences of the University of Torino, presented a new critical edition of the neuropathological films directed by Negro. The Museum's collection also includes 16 mm footage probably filmed in 1930 by Doctor Fedele Negro, Camillo's son. One of these films is devoted to celebrating the effects of the so-called "Bulgarian cure" on Parkinson's disease.

  6. Condensed matter physics

    CERN Document Server

    Isihara, A

    2007-01-01

    More than a graduate text and advanced research guide on condensed matter physics, this volume is useful to plasma physicists and polymer chemists, and their students. It emphasizes applications of statistical mechanics to a variety of systems in condensed matter physics rather than theoretical derivations of the principles of statistical mechanics and techniques. Isihara addresses a dozen different subjects in separate chapters, each designed to be directly accessible and used independently of previous chapters. Topics include simple liquids, electron systems and correlations, two-dimensional

  7. How College Students View a Professor's Role

    Science.gov (United States)

    Gadzella, Bernadette M.

    1977-01-01

    Views of 3,670 students from six colleges and universities on most and least important traits of an ideal professor were analyzed. All data were collected with the same instrument. Data revealed students selected similar MOST and LEAST important traits of a quality professor. (Author)

  8. Finnish Students' Perceptions of a Visiting Professor.

    Science.gov (United States)

    Haussler, Susan C.; Paavilainen, Eija; Astedt-Kurki, Paivi

    2003-01-01

    Finnish nursing students (n=31) evaluated their experience with a visiting Fulbright professor. Students were satisfied with course content, teaching methods, and information about the U.S. health care system. They thought the professor should have been more knowledgeable about Finnish culture, education, and health care. (Contains 15 references.)…

  9. Professor Delight: Cultivating Organizational Citizenship Behavior

    Science.gov (United States)

    Mazen, Abdelmagid; Herman, Susan; Ornstein, Suzyn

    2008-01-01

    This article describes the rationale for and use of a class innovation the authors call "professor delight." This inexpensive, high-yield concept allows students and professors to enact their understanding of citizenship throughout the term, and often beyond. The authors explain the concept, describe its implementation in class, and link it to the…

  10. Simple Simulations of DNA Condensation

    Energy Technology Data Exchange (ETDEWEB)

    STEVENS,MARK J.

    2000-07-12

    Molecular dynamics simulations of a simple, bead-spring model of semiflexible polyelectrolytes such as DNA are performed. All charges are explicitly treated. Starting from extended, noncondensed conformations, condensed structures form in the simulations with tetravalent or trivalent counterions. No condensates form or are stable for divalent counterions. The mechanism by which condensates form is described. Briefly, condensation occurs because electrostatic interactions dominate entropy, and the favored Coulombic structure is a charge ordered state. Condensation is a generic phenomena and occurs for a variety of polyelectrolyte parameters. Toroids and rods are the condensate structures. Toroids form preferentially when the molecular stiffness is sufficiently strong.

  11. Electrons in Condensed Matter

    Indian Academy of Sciences (India)

    entire liquid or solid. The variety of electronic behaviour which ... sity of electronic behaviour in condensed matter, ego ferro- ..... a big dog? We do not know the reasons yet. As it turns out for many fundamentally interesting phenomena, colossal magneto- resistance may also find applications, this time in magnetic recording.

  12. Bose-Einstein Condensation

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 5; Issue 4. Bose–Einstein Condensation - Birds of a Feather Flock Together. Rajaram Nityananda. General Article Volume 5 Issue 4 April 2000 pp 46-51. Fulltext. Click here to view fulltext PDF. Permanent link:

  13. Electrons in Condensed Matter

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 2; Issue 12. Electrons in Condensed Matter. T V Ramakrishnan. General Article Volume 2 Issue 12 December 1997 pp 17-32. Fulltext. Click here to view fulltext PDF. Permanent link: http://www.ias.ac.in/article/fulltext/reso/002/12/0017-0032 ...

  14. Bose-Einstein Condensation

    Indian Academy of Sciences (India)

    gas of photons which explained Planck's law for thermal radiation at one ... their first application. Seventy years later they are being used in atomic physics laboratories all over the world. Everybody is talking about Bose-Einstein condensation. This ... distribution of the position of any particle in the gas is a constant function ...

  15. Bose-Einstein Condensation

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 10; Issue 12. Bose-Einstein Condensation - Birds of a Feather Flock Together. Rajaram Nityananda. Volume 10 Issue 12 December 2005 pp 142-147. Fulltext. Click here to view fulltext PDF. Permanent link:

  16. Modular invariant gaugino condensation

    Energy Technology Data Exchange (ETDEWEB)

    Gaillard, M.K.

    1991-05-09

    The construction of effective supergravity lagrangians for gaugino condensation is reviewed and recent results are presented that are consistent with modular invariance and yield a positive definite potential of the noscale type. Possible implications for phenomenology are briefly discussed. 29 refs.

  17. Condensed Matter Physics

    Science.gov (United States)

    Marder, Michael P.

    2000-01-01

    A modern, unified treatment of condensed matter physics This new work presents for the first time in decades a sweeping review of the whole field of condensed matter physics. It consolidates new and classic topics from disparate sources, teaching "not only about the effective masses of electrons in semiconductor crystals and band theory, but also about quasicrystals, dynamics of phase separation, why rubber is more floppy than steel, electron interference in nanometer-sized channels, and the quantum Hall effect." Six major areas are covered---atomic structure, electronic structure, mechanical properties, electron transport, optical properties, and magnetism. But rather than defining the field in terms of particular materials, the author focuses on the way condensed matter physicists approach physical problems, combining phenomenology and microscopic arguments with information from experiments. For graduate students and professionals, researchers and engineers, applied mathematicians and materials scientists, Condensed Matter Physics provides: * An exciting collection of new topics from the past two decades. * A thorough treatment of classic topics, including band theory, transport theory, and semiconductor physics. * Over 300 figures, incorporating many images from experiments. * Frequent comparison of theory and experiment, both when they agree and when problems are still unsolved. * More than 50 tables of data and a detailed index. * Ample end-of-chapter problems, including computational exercises. * Over 1000 references, both recent and historically significant.

  18. Bose-Einstein condensation in nonuniform media

    Science.gov (United States)

    Sa-Yakanit, Virulh; Yarunin, Vladimir; Nisamaneephong, Pornther

    1998-02-01

    The Bogoliubov model of a nonideal gas is developed for Bose-Einstein condensation (BEC) in media with broken translational symmetry. A decrease of the transition temperature Tλ is found as a function of the ratio {F 1}/{g 0}, where g0 is the interaction between the atoms of the condensate and F1 is the condensate-noncondensate interaction, generated by the nonhomogeneous property of the matter. The shift of Tλ in porous media experimentally found by Wong et al. [Phys. Rev. Lett. 65 (1990) 2410] is applied to estimate the ratio {F 1}/{g 0}, which is found to be equal to 0.1, and may be considered as a measure of the influence of the porosity on the interaction between the atoms.

  19. PROFESSORES: IMAGENS DO FUTURO PRESENTE

    Directory of Open Access Journals (Sweden)

    Maitê Alves Bezerra

    2014-06-01

    Full Text Available Ao observar a comunidade portuguesa que busca compreender a historicidade das formas e dos processos de escolarização por meio do estabelecimento de intenso diálogo com outras comunidades, é impossível não dar destaque à figura de António Manuel Seixas Nóvoa. Nascido em Lisboa no ano de 1954, aos 18 anos inicia o curso de Ciências da Educação na Universidade de Lisboa. Após lecionar em importantes universidades tais como Paris V, Oxford e Columbia University, atualmente acumula as posições de reitor da Universidade de Lisboa e professor catedrático da Faculdade de Psicologia e de Ciências da Educação na Instituição. Nóvoa tem se destacado à frente de debates internacionais a respeito da história da educação e educação comparada.

  20. Recovery of condensate water quality in power generator's surface condenser

    Science.gov (United States)

    Kurniawan, Lilik Adib

    2017-03-01

    In PT Badak NGL Plant, steam turbines are used to drive major power generators, compressors, and pumps. Steam exiting the turbines is condensed in surface condensers to be returned to boilers. Therefore, surface condenser performance and quality of condensate water are very important. One of the recent problem was caused by the leak of a surface condenser of Steam Turbine Power Generator. Thesteam turbine was overhauled, leaving the surface condenser idle and exposed to air for more than 1.5 years. Sea water ingress due to tube leaks worsens the corrosionof the condenser shell. The combination of mineral scale and corrosion product resulting high conductivity condensate at outlet condenser when we restarted up, beyond the acceptable limit. After assessing several options, chemical cleaning was the best way to overcome the problem according to condenser configuration. An 8 hour circulation of 5%wt citric acid had succeed reducing water conductivity from 50 μmhos/cm to below 5 μmhos/cm. The condensate water, then meets the required quality, i.e. pH 8.3 - 9.0; conductivity ≤ 5 μmhos/cm, therefore the power generator can be operated normally without any concern until now.

  1. Condensation enhancement by means of electrohydrodynamic techniques

    Directory of Open Access Journals (Sweden)

    Butrymowicz Dariusz

    2014-12-01

    Full Text Available Short state-of-the-art on the enhancement of condensation heat transfer techniques by means of condensate drainage is presented in this paper. The electrohydrodynamic (EHD technique is suitable for dielectric media used in refrigeration, organic Rankine cycles and heat pump devices. The electric field is commonly generated in the case of horizontal tubes by means of a rod-type electrode or mesh electrodes. Authors proposed two geometries in the presented own experimental investigations. The first one was an electrode placed just beneath the tube bottom and the second one consisted of a horizontal finned tube with a double electrode placed beneath the tube. The experimental investigations of these two configurations for condensation of refrigerant R-123 have been accomplished. The obtained results confirmed that the application of the EHD technique for the investigated tube and electrode arrangement caused significant increase in heat transfer coefficient. The condensation enhancement depends both on the geometry of the electrode system and on the applied voltage.

  2. Condensed matter physics

    CERN Document Server

    Marder, Michael P

    2010-01-01

    This Second Edition presents an updated review of the whole field of condensed matter physics. It consolidates new and classic topics from disparate sources, teaching not only about the effective masses of electrons in semiconductor crystals and band theory, but also about quasicrystals, dynamics of phase separation, why rubber is more floppy than steel, granular materials, quantum dots, Berry phases, the quantum Hall effect, and Luttinger liquids.

  3. Asymmetric condensed dark matter

    Energy Technology Data Exchange (ETDEWEB)

    Aguirre, Anthony; Diez-Tejedor, Alberto, E-mail: aguirre@scipp.ucsc.edu, E-mail: alberto.diez@fisica.ugto.mx [Santa Cruz Institute for Particle Physics and Department of Physics, University of California, Santa Cruz, CA, 95064 (United States)

    2016-04-01

    We explore the viability of a boson dark matter candidate with an asymmetry between the number densities of particles and antiparticles. A simple thermal field theory analysis confirms that, under certain general conditions, this component would develop a Bose-Einstein condensate in the early universe that, for appropriate model parameters, could survive the ensuing cosmological evolution until now. The condensation of a dark matter component in equilibrium with the thermal plasma is a relativistic process, hence the amount of matter dictated by the charge asymmetry is complemented by a hot relic density frozen out at the time of decoupling. Contrary to the case of ordinary WIMPs, dark matter particles in a condensate must be lighter than a few tens of eV so that the density from thermal relics is not too large. Big-Bang nucleosynthesis constrains the temperature of decoupling to the scale of the QCD phase transition or above. This requires large dark matter-to-photon ratios and very weak interactions with standard model particles.

  4. Polymorphism of Lysozyme Condensates.

    Science.gov (United States)

    Safari, Mohammad S; Byington, Michael C; Conrad, Jacinta C; Vekilov, Peter G

    2017-10-05

    Protein condensates play essential roles in physiological processes and pathological conditions. Recently discovered mesoscopic protein-rich clusters may act as crucial precursors for the nucleation of ordered protein solids, such as crystals, sickle hemoglobin polymers, and amyloid fibrils. These clusters challenge settled paradigms of protein condensation as the constituent protein molecules present features characteristic of both partially misfolded and native proteins. Here we employ the antimicrobial enzyme lysozyme and examine the similarities between mesoscopic clusters, amyloid structures, and disordered aggregates consisting of chemically modified protein. We show that the mesoscopic clusters are distinct from the other two classes of aggregates. Whereas cluster formation and amyloid oligomerization are both reversible, aggregation triggered by reduction of the intramolecular S-S bonds is permanent. In contrast to the amyloid structures, protein molecules in the clusters retain their enzymatic activity. Furthermore, an essential feature of the mesoscopic clusters is their constant radius of less than 50 nm. The amyloid and disordered aggregates are significantly larger and rapidly grow. These findings demonstrate that the clusters are a product of limited protein structural flexibility. In view of the role of the clusters in the nucleation of ordered protein solids, our results suggest that fine-tuning the degree of protein conformational stability is a powerful tool to control and direct the pathways of protein condensation.

  5. Professor dr hab. Anna Maria Bujakiewicz

    Directory of Open Access Journals (Sweden)

    Anna Kujawa

    2015-08-01

    Full Text Available The article presents the biography and scientific achievements of Professor Anna Bujakiewicz. After receiving her master’s degree and doctorate in biology and mycology from Adam Mickiewicz University in Poznań, Professor Bujakiewicz continued her exciting research and teaching on mycology at her Alma Mater Posnaniensis for more than 50 years. Her publications in this field include many books, articles, and other scholarly reports.

  6. Dedication to Professor Hannspeter Winter (1941 2006): Dedication to Professor Hannspeter Winter (1941 2006)

    Science.gov (United States)

    McCullough, Bob

    2007-03-01

    Professor H Winter. It was with great sadness that we learnt of the death of colleague and friend Professor Hannspeter Winter in Vienna on the 8 November 2006. In memory of him and the contribution he made both to our conference and to the field of the physics of highly charged ions we dedicate these proceedings. Hannspeter was one of our distinguished invited speakers at HCI2006 and gave a talk on the status of the ITER programme. His invited paper on the subject is included in these proceedings. Hannspeter will be particularly remembered for his pioneering work on ion-surface interactions that, together with his colleagues at the Vienna University of Technology (TUW), has stimulated a worldwide experimental and theoretical interest in this field. He was appointed Director of the Institut fuer Allgemeine Physik at TUW in 1987 and using both his scientific and management skills has made it one of the leading university physics laboratories in the world. His research publications, of which there are 270, have inspired many others to work in the field of atomic and plasma physics. He was also a great European playing a major role in the EURATOM fusion programme, the European Physical Society and the International Union of Pure and Applied Physics and was an evaluator and advisory board member for many national and international institutions. Hannspeter was also an interesting and friendly social companion with interests in current affairs, music and fine wines and will be greatly missed both on a scientific and social level. Our condolences go to his wife Renate, son Dorian and his relatives. R W McCullough Co-chair HCI2006

  7. CFD simulation on condensation inside a Hybrid SIT

    Energy Technology Data Exchange (ETDEWEB)

    Jeon, Byong Guk; Ryu, Sung Uk; Kim, Seok; Euh, Dong Jin [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2016-10-15

    The concept of Hybrid Safety Injection Tank system (Hybrid SIT) was proposed by Korea Atomic Energy Research Institute (KAERI) aiming at Advanced Power Reactor Plus. The main advantage of the system is the ready injection of coolant into the reactor coolant system at high pressure. In this paper, a CFD simulation is conducted as a preliminary study. In Hybrid SITs, condensation inside the tank affects its pressure rise and injection time. In an attempt to explore the condensation in detail, we manufactured a dedicated experimental facility for visualization of condensation-induced thermal mixing and conducted a preliminary CFD simulation. Its condensation models were validated first and then computational domain was constructed. The water region was modeled as a solid for stable calculation. The CFD results gave less condensation and excessive pressurization because of lack of steam penetration into the water. In the future, the water region will be modeled as liquid using a VOF model.

  8. Differences between Male Students' and Female Students' Perception of Professors

    Science.gov (United States)

    Tomkiewicz, Joseph; Bass, Kenneth

    2008-01-01

    This study is an empirical examination of possible differences between female and male college seniors' perceptions between male and female college professors. Subjects were presented with three variations of a scale designed to measure students' perceptions of university professors in general, female professors, and male professors. These…

  9. Bose-Einstein condensation and indirect excitons: a review.

    Science.gov (United States)

    Combescot, Monique; Combescot, Roland; Dubin, François

    2017-06-01

    We review recent progress on Bose-Einstein condensation (BEC) of semiconductor excitons. The first part deals with theory, the second part with experiments. This Review is written at a time where the problem of exciton Bose-Einstein condensation has just been revived by the understanding that the exciton condensate must be dark because the exciton ground state is not coupled to light. Here, we theoretically discuss this missed understanding before providing its experimental support through experiments that scrutinize indirect excitons made of spatially separated electrons and holes. The theoretical part first discusses condensation of elementary bosons. In particular, the necessary inhibition of condensate fragmentation by exchange interaction is stressed, before extending the discussion to interacting bosons with spin degrees of freedom. The theoretical part then considers composite bosons made of two fermions like semiconductor excitons. The spin structure of the excitons is detailed, with emphasis on the crucial fact that ground-state excitons are dark: indeed, this imposes the exciton Bose-Einstein condensate to be not coupled to light in the dilute regime. Condensate fragmentations are then reconsidered. In particular, it is shown that while at low density, the exciton condensate is fully dark, it acquires a bright component, coherent with the dark one, beyond a density threshold: in this regime, the exciton condensate is 'gray'. The experimental part first discusses optical creation of indirect excitons in quantum wells, and the detection of their photoluminescence. Exciton thermalisation is also addressed, as well as available approaches to estimate the exciton density. We then switch to specific experiments where indirect excitons form a macroscopic fragmented ring. We show that such ring provides efficient electrostatic trapping in the region of the fragments where an essentially-dark exciton Bose-Einstein condensate is formed at sub-Kelvin bath

  10. Tachyon condensation due to domain-wall annihilation in Bose-Einstein condensates.

    Science.gov (United States)

    Takeuchi, Hiromitsu; Kasamatsu, Kenichi; Tsubota, Makoto; Nitta, Muneto

    2012-12-14

    We show theoretically that a domain-wall annihilation in two-component Bose-Einstein condensates causes tachyon condensation accompanied by spontaneous symmetry breaking in a two-dimensional subspace. Three-dimensional vortex formation from domain-wall annihilations is considered a kink formation in subspace. Numerical experiments reveal that the subspatial dynamics obey the dynamic scaling law of phase-ordering kinetics. This model is experimentally feasible and provides insights into how the extra dimensions influence subspatial phase transition in higher-dimensional space.

  11. Confinement Contains Condensates

    Energy Technology Data Exchange (ETDEWEB)

    Brodsky, Stanley J.; Roberts, Craig D.; Shrock, Robert; Tandy, Peter C.

    2012-03-12

    Dynamical chiral symmetry breaking and its connection to the generation of hadron masses has historically been viewed as a vacuum phenomenon. We argue that confinement makes such a position untenable. If quark-hadron duality is a reality in QCD, then condensates, those quantities that have commonly been viewed as constant empirical mass-scales that fill all spacetime, are instead wholly contained within hadrons; i.e., they are a property of hadrons themselves and expressed, e.g., in their Bethe-Salpeter or light-front wave functions. We explain that this paradigm is consistent with empirical evidence, and incidentally expose misconceptions in a recent Comment.

  12. Topology in Condensed Matter

    CERN Document Server

    Monastyrsky, M I

    2006-01-01

    This book reports new results in condensed matter physics for which topological methods and ideas are important. It considers, on the one hand, recently discovered systems such as carbon nanocrystals and, on the other hand, new topological methods used to describe more traditional systems such as the Fermi surfaces of normal metals, liquid crystals and quasicrystals. The authors of the book are renowned specialists in their fields and present the results of ongoing research, some of it obtained only very recently and not yet published in monograph form.

  13. Counterion condensation and release in micellar solutions

    Science.gov (United States)

    Hsiao, Chin Chieh; Wang, Tzu-Yu; Tsao, Heng-Kwong

    2005-04-01

    Counterion condensation and release in micellar solutions are investigated by direct measurement of counterion concentration with ion-selective electrode. Monte Carlo simulations based on the cell model are also performed to analyze the experimental results. The degree of counterion condensation is indicated by the concentration ratio of counterions in the bulk to the total ionic surfactant added, α⩽1. The ionic surfactant is completely dissociated below the critical micelle concentration (cmc). However, as cmc is exceeded, the free counterion ratio α declines with increasing the surfactant concentration and approaches an asymptotic value owing to counterion condensation to the surface of the highly charged micelles. Micelle formation leads to much stronger electrostatic attraction between the counterion and the highly charged sphere in comparison to the attraction of single surfactant ion with its counterion. A simple model is developed to obtain the true degree of ionization, which agrees with our Monte Carlo results. Upon addition of neutral polymer or monovalent salts, some of the surfactant counterions are released to the bulk. The former is due to the decrease of the intrinsic charge (smaller aggregation number) and the degree of ionization is increased. The latter is attributed to competitive counterion condensation, which follows the Hefmeister series. This consequence indicates that the specific ion effect plays an important role next to the electrostatic attraction.

  14. Accounting Professor Qualification in Digital Age: A Perception Study on Brazilian Professors

    Science.gov (United States)

    Vendruscolo, Maria Ivanice; Behar, Patrícia Alejandra

    2015-01-01

    This papers aims at analyzing the perception of Accounting professors about the necessary qualifications in Accounting undergraduate courses. The contribution of this study is to theoretically discuss the education of Accounting professors, with empirical data, because Accounting teaching requires specific competencies in the digital area. The…

  15. Increased ionization supports growth of aerosols into cloud condensation nuclei

    DEFF Research Database (Denmark)

    Svensmark, H.; Enghoff, M. B.; Shaviv, N. J.

    2017-01-01

    Ions produced by cosmic rays have been thought to influence aerosols and clouds. In this study, the effect of ionization on the growth of aerosols into cloud condensation nuclei is investigated theoretically and experimentally. We show that the mass-flux of small ions can constitute an important...... addition to the growth caused by condensation of neutral molecules. Under atmospheric conditions the growth from ions can constitute several percent of the neutral growth. We performed experimental studies which quantify the effect of ions on the growth of aerosols between nucleation and sizes >20 nm...... and find good agreement with theory. Ion-induced condensation should be of importance not just in Earth’s present day atmosphere for the growth of aerosols into cloud condensation nuclei under pristine marine conditions, but also under elevated atmospheric ionization caused by increased supernova activity....

  16. Increased ionization supports growth of aerosols into cloud condensation nuclei.

    Science.gov (United States)

    Svensmark, H; Enghoff, M B; Shaviv, N J; Svensmark, J

    2017-12-19

    Ions produced by cosmic rays have been thought to influence aerosols and clouds. In this study, the effect of ionization on the growth of aerosols into cloud condensation nuclei is investigated theoretically and experimentally. We show that the mass-flux of small ions can constitute an important addition to the growth caused by condensation of neutral molecules. Under atmospheric conditions the growth from ions can constitute several percent of the neutral growth. We performed experimental studies which quantify the effect of ions on the growth of aerosols between nucleation and sizes >20 nm and find good agreement with theory. Ion-induced condensation should be of importance not just in Earth's present day atmosphere for the growth of aerosols into cloud condensation nuclei under pristine marine conditions, but also under elevated atmospheric ionization caused by increased supernova activity.

  17. Iterated Dynamic Condensation Technique and Its Applications in Modal Testing

    Directory of Open Access Journals (Sweden)

    Zhikun Hou

    1997-01-01

    Full Text Available This article addresses an application of the dynamic condensation in modal testing, which requires measurements of natural frequencies and a limited number of components of modal shapes only. The measured frequencies can be employed as the initial estimates in the iterated dynamic condensation to effectively find an exact solution for the original eigenvalue problem and determine the transformation matrix between the testing and nontesting coordinates. Complete modal shapes including the nontesting coordinates can then be estimated based on the limited measurements. Numerical results are presented to illustrate the feasibility and efficiency of the iterated dynamic condensation. A comparison with the experimental results of a multiple disk system is also provided.

  18. Physics through the 1990s: Condensed-matter physics

    Science.gov (United States)

    1986-01-01

    The volume presents the current status of condensed-matter physics from developments since the 1970s to opportunities in the 1990s. Topics include electronic structure, vibrational properties, critical phenomena and phase transitions, magnetism, semiconductors, defects and diffusion, surfaces and interfaces, low-temperature physics, liquid-state physics, polymers, nonlinear dynamics, instabilities, and chaos. Appendices cover the connections between condensed-matter physics and applications of national interest, new experimental techniques and materials, laser spectroscopy, and national facilities for condensed-matter physics research. The needs of the research community regarding support for individual researchers and for national facilities are presented, as are recommendations for improved government-academic-industrial relations.

  19. Design and analysis of a 5-MW vertical-fluted-tube condenser for geothermal applications

    Energy Technology Data Exchange (ETDEWEB)

    Llewellyn, G.H.

    1982-03-01

    The design and analysis of an industtial-sized vertical-fluted-tube condenser. The condenser is used to condense superheated isobutane vapor discharged from a power turbine in a geothermal test facility operated for the US Department of Energy. The 5-MW condenser has 1150 coolant tubes in a four-pass configuration with a total heat transfer area of 725 m/sup 2/ (7800 ft/sup 2/). The unit is being tested at the Geothermal Components Test Facility in the Imperial Valley of East Mesa, California. The condenser design is based on previous experimental research work done at the Oak Ridge National Laboratory on condensing refrigerants on a wide variety of single vertical tubes. Condensing film coefficients obtained on the high-performance vertical fluted tubes in condensing refrigerants are as much as seven times greater than those obtained with vertical smooth tubes that have the same diameter and length. The overall heat transfer performance expected from the fluted tube condenser is four to five times the heat transfer obtained from the identical units employing smooth tubes. Fluted tube condensers also have other direct applications in the Ocean Thermal Energy Conversion (OTEC) program in condensing ammonia, in the petroleum industry in condensing light hydrocarbons, and in the air conditioning and refrigeration industry in condensing fluorocarbon vapors.

  20. The housekeeper and the professor a novel

    CERN Document Server

    Ogawa, Yoko

    2010-01-01

    He is a brilliant math Professor with a peculiar problem—ever since a traumatic head injury, he has lived with only eighty minutes of short-term memory. She is an astute young Housekeeper—with a ten-year-old son—who is hired to care for the Professor. And every morning, as the Professor and the Housekeeper are introduced to each other anew, a strange and beautiful relationship blossoms between them. Though he cannot hold memories for long (his brain is like a tape that begins to erase itself every eighty minutes), the Professor's mind is still alive with elegant equations from the past. And the numbers, in all of their articulate order, reveal a sheltering and poetic world to both the Housekeeper and her young son. The Professor is capable of discovering connections between the simplest of quantities—like the Housekeeper's shoe size—and the universe at large, drawing their lives ever closer and more profoundly together, even as his memory slips away. Yoko Ogawa's The Housekeeper and the Professo...

  1. Stimulated emission of dark matter axion from condensed matter excitations

    OpenAIRE

    Yokoi, Naoto; Saitoh, Eiji

    2018-01-01

    We discuss a possible principle for detecting dark matter axions in galactic halos. If axions constitute a condensate in the Milky Way, stimulated emissions of the axions from a type of excitation in condensed matter can be detectable. We provide general mechanism for the dark matter emission, and, as a concrete example, an emission of dark matter axions from magnetic vortex strings in a type II superconductor is investigated along with possible experimental signatures.

  2. Assessment of RELAP5/MOD3 with condensation experiment for pure steam condensation in a vercal tube

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sang Jae; No, Hee Cheon [Korea Advanced Institute of Science and Technology, Taejon (Korea, Republic of)

    1998-12-31

    The film condensation models in RELAP5/MOD3.1 and RELAP5/MOD3.2 are assessed with the data of experiment performed in the scaled down condensation experimental facility with a single vertical tube of inner diameter of 46 mm in the range of pressure 0.1 {approx} 7.5 MPa for the PSCS(Passive Secondary Condenser System). Both MOD3.1 and MOD3.2 don`t shows any reliable predictions of the experimental data. The RELAP5/MOD3.1 overpredicts the heat transfer coefficients of experiment, whereas the RELAP5/MOD3.2 underpredicts those data. It is recommended that the film condensation model in RELAP5/MOD3.2 should be modified to have a larger heat transfer coefficient than those of the present model to give the reliable predictions. 7 refs., 6 figs., 1 tab. (Author)

  3. INTRODUCTION: Award of the 2003 Hannes Alfvén Prize of the European Physical Society to Professor Vladimir Evgenievitch Fortov

    Science.gov (United States)

    Wagner, F.

    2003-12-01

    The Hannes Alfvén Prize of the European Physical Society for Outstanding Contributions to Plasma Physics (2003) has been awarded to Vladimir Evgenievitch Fortov `for his seminal contributions in the area of non-ideal plasmas and strongly coupled Coulomb systems, and for his pioneering work on the generation and investigation of plasmas under extreme conditions'. Vladimir Evgenievitch Fortov was born on 23 January 1946 in Noginsk, Russia. He studied physics at the Moscow Institute of Physics and Technology (PhD in 1976). In 1978 he was made a Professor and in 1991 he was awarded the Chair of the Moscow Institute of Physics and Technology. In the same year he became a Member of the Russian Academy of Sciences and was its vice-chairman from 1996 to 2001. From 1996 to 1998, Professor Fortov went into politics where he was just as successful, becoming Deputy Prime Minister of the Government of the Russian Federation and Minister of Science and Technology of the Russian Federation. Professor Fortov has made outstanding experimental and theoretical contributions to low temperature plasma physics. His pioneering work investigating non-ideal plasmas produced by intense shock waves initiated a new research field---the physical properties of highly compressed plasmas with strong inter-particle interactions. Under the leadership of Professor Fortov, experimental methods for generating and diagnosing these plasmas under extreme conditions were developed. To generate intense shock waves, a broad spectrum of drivers was used---chemical explosives, hypervelocity impact, lasers, relativistic electrons, heavy-ion and soft x-ray beams. Measurements of the equation of state, transport and optical properties of strongly coupled plasmas were carried out, including the interesting region lying between condensed matter and rarefied plasmas where specific plasma phase transitions and insulator--metal transitions were expected and explored. In another area of strongly coupled plasmas

  4. Modeling of Pressure Drop During Refrigerant Condensation in Pipe Minichannels

    Science.gov (United States)

    Sikora, Małgorzata; Bohdal, Tadeusz

    2017-12-01

    Investigations of refrigerant condensation in pipe minichannels are very challenging and complicated issue. Due to the multitude of influences very important is mathematical and computer modeling. Its allows for performing calculations for many different refrigerants under different flow conditions. A large number of experimental results published in the literature allows for experimental verification of correctness of the models. In this work is presented a mathematical model for calculation of flow resistance during condensation of refrigerants in the pipe minichannel. The model was developed in environment based on conservation equations. The results of calculations were verified by authors own experimental investigations results.

  5. Damping and frequency shift in the oscillations of two colliding Bose-Einstein condensates

    Science.gov (United States)

    Modugno, M.; Fort, C.; Maddaloni, P.; Minardi, F.; Inguscio, M.

    2001-12-01

    We have investigated the center-of-mass oscillations of a 87Rb Bose-Einstein condensate in an elongated magneto-static trap. We start from a trapped condensate and we transfer part of the atoms to another trapped level, by applying a radio-frequency pulse. The new condensate is produced far from its equilibrium position in the magnetic potential, and periodically collides with the parent condensate. We discuss how both the damping and the frequency shift of the oscillations are affected by the mutual interaction between the two condensates, in a wide range of trapping frequencies. The experimental data are compared with the prediction of a mean-field model.

  6. Microgravity condensing heat exchanger

    Science.gov (United States)

    Thomas, Christopher M. (Inventor); Ma, Yonghui (Inventor); North, Andrew (Inventor); Weislogel, Mark M. (Inventor)

    2011-01-01

    A heat exchanger having a plurality of heat exchanging aluminum fins with hydrophilic condensing surfaces which are stacked and clamped between two cold plates. The cold plates are aligned radially along a plane extending through the axis of a cylindrical duct and hold the stacked and clamped portions of the heat exchanging fins along the axis of the cylindrical duct. The fins extend outwardly from the clamped portions along approximately radial planes. The spacing between fins is symmetric about the cold plates, and are somewhat more closely spaced as the angle they make with the cold plates approaches 90.degree.. Passageways extend through the fins between vertex spaces which provide capillary storage and communicate with passageways formed in the stacked and clamped portions of the fins, which communicate with water drains connected to a pump externally to the duct. Water with no entrained air is drawn from the capillary spaces.

  7. Professor Karel Oštir zum andenken

    Directory of Open Access Journals (Sweden)

    Bojan Čop

    1973-12-01

    Full Text Available Die Redaktion der Zeitschrift tinguistica beschloss am Anfang des Jahres 1973, den XIII.Jg. der Vollendung des fünfundachtzigsten Lebensjahres, die Professor Karel Oštir am 13. Oktober feiern sollte, zu widmen. Da sich aber das Sammeln des Materials für diesen Jahrgang sowie der Druck des XII. Jahrganges allzusehr in die Länge gezogen hatten, ist uns das unerbittliche Schicksal zuvorgekommen: am 27. Dezember 1973 ist Professor Karel Oštir sanft entschlafen. Das Leben eines der eigenartigsten Sprachwissenschaftler aller Zei ten hat sich so erfüllt. Aus einer Festschrift musste nun eine Gedenkschrift werden.

  8. Professor Stewart's casebook of mathematical mysteries

    CERN Document Server

    Stewart, Ian

    2014-01-01

    Like its wildly popular predecessors Cabinet of Mathematical Curiosities and Hoard of Mathematical Treasures, Professor Stewart's brand-new book is a miscellany of over 150 mathematical curios and conundrums, packed with trademark humour and numerous illustrations. In addition to the fascinating formulae and thrilling theorems familiar to Professor Stewart's fans, the Casebook follows the adventures of the not-so-great detective Hemlock Soames and his sidekick Dr John Watsup (immortalised in the phrase 'Watsup, Doc?'). By a remarkable coincidence they live at 222B Baker Street, just a

  9. Estimation of the Influence of Operational Factors on the Oxygen Content of the Turbine Condensate at the Outlet from the Condenser of Steam Turbine

    Directory of Open Access Journals (Sweden)

    Shempelev A. G.

    2017-08-01

    Full Text Available The aim of the article is to analyze the influence of different factors on the oxygen content in the condensate using the example of the condenser of the steam turbine unit T-110/120-130. For the first time, the authors of the article analyze in details how the basic parameters of the condenser's operation (the condenser heat load, the flow and temperature of the cooling water, the air inflow in the condenser, the condition of the heat exchange surface influence the oxygen content of the condensate. The authors come to the conclusion that with standard air inflow in the vacuum system, the equilibrium oxygen content, which corresponds to the norms in the condensate at the condenser outlet, is only possible in its operation modes when the steam flow to the condenser is more than 50% of the nominal flow and cooling water temperatures are equal to or greater than calculated for this type of condenser. The conclusions are confirmed by the experimental material. The results of the research are the basis for the development of measures aimed to increase the deaerating capacity of condensers depending on specific operating conditions.

  10. Bose-Einstein condensation and superfluidity

    CERN Document Server

    Pitaevskii, Lev

    2016-01-01

    This volume introduces the basic concepts of Bose–Einstein condensation and superfluidity. It makes special reference to the physics of ultracold atomic gases; an area in which enormous experimental and theoretical progress has been achieved in the last twenty years. Various theoretical approaches to describing the physics of interacting bosons and of interacting Fermi gases, giving rise to bosonic pairs and hence to condensation, are discussed in detail, both in uniform and harmonically trapped configurations. Special focus is given to the comparison between theory and experiment, concerning various equilibrium, dynamic, thermodynamic, and superfluid properties of these novel systems. The volume also includes discussions of ultracold gases in dimensions, quantum mixtures, and long-range dipolar interactions.

  11. A superheated Bose-condensed gas

    Science.gov (United States)

    Gaunt, Alexander L.; Fletcher, Richard J.; Smith, Robert P.; Hadzibabic, Zoran

    2013-05-01

    Our understanding of various states of matter usually relies on the assumption of thermodynamic equilibrium. However, the transitions between different phases of matter can be strongly affected by non-equilibrium phenomena. Here we demonstrate and explain an example of non-equilibrium stalling of a continuous, second-order phase transition. We create a superheated atomic Bose gas, in which a Bose-Einstein condensate (BEC) persists above the equilibrium critical temperature, Tc, if its coupling to the surrounding thermal bath is reduced by tuning interatomic interactions. For vanishing interactions the BEC persists in the superheated regime for a minute. However, if strong interactions are suddenly turned on, it rapidly boils away. Our observations can be understood within a two-fluid picture, treating the condensed and thermal components of the gas as separate equilibrium systems with a tunable inter-component coupling. We experimentally reconstruct a non-equilibrium phase diagram of our gas, and theoretically reproduce its main features.

  12. Supersymmetry is afraid of condensates

    Directory of Open Access Journals (Sweden)

    G. Domokos

    1983-01-01

    Full Text Available Supersymmetry is never broken by pair condensates of chiral superfields: the supersymmetry breaking part of Green's functions satisfies an equation which always has an identically vanishing solution. Hence any phase containing pair condensates is unstable due to its positive vacuum energy.

  13. CFD simulation of steam–air jet condensation

    Energy Technology Data Exchange (ETDEWEB)

    Qu, Xiao-hang [School of Energy and Power Engineering, Shandong University, Jinan 250061, Shandong (China); Sui, Hui [Shandong Laigang Energy Conservation and Environmental Protection Engineering Co., Ltd, Laiwu 271133, Shandong (China); Tian, Mao-cheng, E-mail: tianmc65@sdu.edu.cn [School of Energy and Power Engineering, Shandong University, Jinan 250061, Shandong (China)

    2016-02-15

    Highlights: • Steam–air mixture jet direct contact condensation behavior is studied numerically. • Euler–Euler two-fluid model and species model are coupled to simulated jet condensation. • Thermal phase change model is used to account for interphase mass transfer. • Gas volume fraction from simulation is corrected for comparison with experiment. • Temperature and gas volume fraction distributions agree reasonably with experimental results. - Abstract: A three dimensional model was established based on Euler–Euler two-fluid model to simulate the steam jet direct contact condensation with air involved. Condensation of steam in the gas mixture was realized using thermal phase change model. Species transport equation for the gas phase was employed to account for composition variation of the steam air mixture. The investigated gas mass flux at nozzle exit was within 300 kg/m{sup 2}/s, with non-condensable air of less than 10%. Numerical results show the steam in gas plume condenses rapidly after leaving the nozzle, until only air and a little uncondensed steam remain in the gas plume. The addition of air in the jet deteriorates the condensation heat transfer, leading temperature and void fraction around the nozzle to decrease more slowly in both axial and radial directions. Five cases of experimental results were demonstrated with three of them validating the temperature distribution and two of them validating the void fraction. The comparison between numerical and experimental results demonstrates the CFD model can predict the steam–air jet condensation process quite reasonably.Classification: K. Thermal hydraulics.

  14. Chromatin condensation during terminal erythropoiesis.

    Science.gov (United States)

    Zhao, Baobing; Yang, Jing; Ji, Peng

    2016-09-02

    Mammalian terminal erythropoiesis involves gradual but dramatic chromatin condensation steps that are essential for cell differentiation. Chromatin and nuclear condensation is followed by a unique enucleation process, which is believed to liberate more spaces for hemoglobin enrichment and enable the generation of a physically flexible mature red blood cell. Although these processes have been known for decades, the mechanisms are still unclear. Our recent study reveals an unexpected nuclear opening formation during mouse terminal erythropoiesis that requires caspase-3 activity. Major histones, except H2AZ, are partially released from the opening, which is important for chromatin condensation. Block of the nuclear opening through caspase inhibitor or knockdown of caspase-3 inhibits chromatin condensation and enucleation. We also demonstrate that nuclear opening and histone release are cell cycle regulated. These studies reveal a novel mechanism for chromatin condensation in mammalia terminal erythropoiesis.

  15. Decay of Ultralight Axion Condensates

    Energy Technology Data Exchange (ETDEWEB)

    Eby, Joshua; Ma, Michael; Suranyi, Peter; Wijewardhana, L. C.R.

    2017-05-15

    Axion particles can form macroscopic condensates, whose size can be galactic in scale for models with very small axion masses $m\\sim10^{-22}$ eV, and which are sometimes referred to under the name of Fuzzy Dark Matter. Many analyses of these condensates are done in the non-interacting limit, due to the weakness of the self-interaction coupling of axions. We investigate here how certain results change upon inclusion of these interactions, finding a decreased maximum mass and a modified mass-radius relationship. Further, these condensates are, in general, unstable to decay through number-changing interactions. We analyze the stability of galaxy-sized condensates of axion-like particles, and sketch the parameter space of stable configurations as a function of a binding energy parameter. We find a strong lower bound on the size of Fuzzy Dark Matter condensates which are stable to decay, with lifetimes longer than the age of the universe.

  16. Ice-condenser aerosol tests

    Energy Technology Data Exchange (ETDEWEB)

    Ligotke, M.W.; Eschbach, E.J.; Winegardner, W.K. (Pacific Northwest Lab., Richland, WA (United States))

    1991-09-01

    This report presents the results of an experimental investigation of aerosol particle transport and capture using a full-scale height and reduced-scale cross section test facility based on the design of the ice compartment of a pressurized water reactor (PWR) ice-condenser containment system. Results of 38 tests included thermal-hydraulic as well as aerosol particle data. Particle retention in the test section was greatly influenced by thermal-hydraulic and aerosol test parameters. Test-average decontamination factor (DF) ranged between 1.0 and 36 (retentions between {approximately}0 and 97.2%). The measured test-average particle retentions for tests without and with ice and steam ranged between DF = 1.0 and 2.2 and DF = 2.4 and 36, respectively. In order to apparent importance, parameters that caused particle retention in the test section in the presence of ice were steam mole fraction (SMF), noncondensible gas flow rate (residence time), particle solubility, and inlet particle size. Ice-basket section noncondensible flows greater than 0.1 m{sup 3}/s resulted in stable thermal stratification whereas flows less than 0.1 m{sup 3}/s resulted in thermal behavior termed meandering with frequent temperature crossovers between flow channels. 10 refs., 66 figs., 16 tabs.

  17. Kai Adolf Jensen, professor i almindelig patologi

    DEFF Research Database (Denmark)

    Høiby, Niels

    2016-01-01

    for the Bacillus Calmette-Guérin vaccine production and supervised many young scientists’ doctoral theses on the aspects of tuberculosis. He became internationally recognized, and he revealed an important scientific fraud in the laboratory of the Austrian professor Ernst Löwenstein (1878-1950), who claimed that he...

  18. String theorist takes over as Lucasian Professor

    Science.gov (United States)

    Banks, Michael

    2009-11-01

    String theorist Michael Green will be the next Lucasian Professor of Mathematics at Cambridge University. Green, 63, will succeed Stephen Hawking, who held the chair from 1980 before retiring last month at the age of 67 and taking up a distinguished research chair at the Perimeter Institute for Theoretical Physics in Canada (see above).

  19. Epistemology Shock: English Professors Confront Science

    Science.gov (United States)

    Barnard, Ian; Osborn, Jan

    2017-01-01

    This article raises questions and concerns regarding students from the sciences working with faculty in the humanities in interdisciplinary settings. It explores the experience of two English professors facing the privileging of "facts" and a science-based understanding of the world in their own classrooms. It poses both questions and…

  20. Understanding Asperger Syndrome: A Professor's Guide [DVD

    Science.gov (United States)

    Organization for Autism Research (NJ3), 2011

    2011-01-01

    College can be a trying time in any individual's life. For adults with Asperger Syndrome this experience can be overwhelming. This title in the new DVD series Asperger Syndrome and Adulthood focuses on educating professors, teaching assistants, and others on what it means to be a college student on the spectrum and how they might best be able to…

  1. Professor Brand Advocacy: Do Brand Relationships Matter?

    Science.gov (United States)

    Jillapalli, Ravi K.; Wilcox, James B.

    2010-01-01

    The trend among students to advocate their professors online continues to generate interest within marketing academia. Brand advocacy in products and services has played a vital role in marketing. However, no known research to date has embraced the idea of brand advocacy in marketing education. This research builds on the recent human brand…

  2. Forestry professors and students receive national recognition

    OpenAIRE

    Davis, Lynn

    2005-01-01

    Two Virginia Tech professors in the College of Natural Resources and the university's Society of American Foresters student chapter received awards for their accomplishments at the Society of American Foresters 2005 national convention held in Fort Worth, Texas, earlier this month.

  3. Two business professors receive Fulbright Scholar awards

    OpenAIRE

    Ho, Sookhan

    2005-01-01

    Virginia Tech Pamplin College of Business professors Larry French and Mahmood A. Khan have received Fulbright Scholar Awards to teach and conduct research abroad next year. Both faculty members teach in the MBA program at the university's Northern Virginia Center in metro Washington, D.C.

  4. The Supervisor Is Not the Professor

    Science.gov (United States)

    Johnson, G. Stewart; Shafer, Carl

    1970-01-01

    College educational exposure does not prepare the graduate for the human relations demands of teamwork in industry, and may not prepare the graduate for the relationship with his supervisor. Five major dimensions of difference for the student between his interaction with his professors and his new relationships with his supervisor are: degree of…

  5. "Dear Professor: I Hate You"--Anonymous

    Science.gov (United States)

    Bartlett, Thomas

    2009-01-01

    Flip through a stack of anonymous student evaluations of professors and the mild comments, even the compliments, tend to blend together. But often, hidden among them, is a dagger. Then there are the out-and-out insults. Students' comments can be more than simply mean. Sometimes student comments aren't cruel, just weird. In this article, some…

  6. Africa's New Crisis: A Dearth of Professors

    Science.gov (United States)

    Lindow, Megan

    2009-01-01

    With many professors approaching retirement. a shortage of qualified academics has reached crisis proportions at a number of African universities. The shortfall is a consequence of decades of neglect of African higher education, as donors and governments concentrated limited resources on primary and secondary schools, and young scholars who manage…

  7. Professor Jacques Cortes prantsuse keele lektoraadis

    Index Scriptorium Estoniae

    2000-01-01

    Juuni alguses külastas filoloogiateaduskonna romaani-germaani filoloogia osakonda Roueni ülikooli professor Jacques Cortes (Prantsusmaa). Ta korraldas 4. õa üliõpilastele prantsuse keele intensiivkursuse ja võttis vastu eksami ning kohtus prantsuse keele lektoraadi õppejõududega : [täistekst

  8. Microcomputing Competencies for Special Education Professors.

    Science.gov (United States)

    Blackhurst, A. Edward; And Others

    1987-01-01

    A list of microcomputing competencies associated with functions that special education professors typically perform was assessed by 148 special education faculty who use microcomputers. Word processing was rated as the single most useful competency, along with the category of providing instruction about microcomputer applications in special…

  9. Veterinary medicine professor receives national honor

    OpenAIRE

    Douglas, Jeffrey S.

    2005-01-01

    Marie-Suthers-McCabe, of Riner, Va., associate professor of small animal clinical sciences at the Virginia-Maryland Regional College of Veterinary Medicine, has been awarded the highest honor in the nation for work in the area of the "human/animal bond."

  10. CFA or CFP: A Guide for Professors

    Science.gov (United States)

    Moy, Ronald L.

    2011-01-01

    The CFA Institute and the CFP Board of Standards provide professional certifications in the field of finance. In this paper, I provide my experience with the CFA and CFP programs in order to give other professors some insight into the process of attaining the designations. I hope to provide answers to some of the questions that other faculty…

  11. Family Law and Family Studies: Professor's Views

    Science.gov (United States)

    Hicks, Mary W.; And Others

    1977-01-01

    The results of a survey of family studies faculty concerning the inclusion of family law topics in family studies courses are discussed. The professor's needs for training and resources in the area of family and the law are identified and recommendations for meeting these needs are suggested. (Author)

  12. Professor Attitudes and Beliefs about Teaching Evolution

    Science.gov (United States)

    Barnes, Maryann Elizabeth

    Teaching evolution has been shown to be a challenge for faculty, in both K-12 and postsecondary education. Many of these challenges stem from perceived conflicts not only between religion and evolution, but also faculty beliefs about religion, it's compatibility with evolutionary theory, and it's proper role in classroom curriculum. Studies suggest that if educators engage with students' religious beliefs and identity, this may help students have positive attitudes towards evolution. The aim of this study was to reveal attitudes and beliefs professors have about addressing religion and providing religious scientist role models to students when teaching evolution. 15 semi-structured interviews of tenured biology professors were conducted at a large Midwestern universiy regarding their beliefs, experiences, and strategies teaching evolution and particularly, their willingness to address religion in a class section on evolution. Following a qualitative analysis of transcripts, professors did not agree on whether or not it is their job to help students accept evolution (although the majority said it is not), nor did they agree on a definition of "acceptance of evolution". Professors are willing to engage in students' religious beliefs, if this would help their students accept evolution. Finally, professors perceived many challenges to engaging students' religious beliefs in a science classroom such as the appropriateness of the material for a science class, large class sizes, and time constraints. Given the results of this study, the author concludes that instructors must come to a consensus about their goals as biology educators as well as what "acceptance of evolution" means, before they can realistically apply the engagement of student's religious beliefs and identity as an educational strategy.

  13. Water condensation: a multiscale phenomenon.

    Science.gov (United States)

    Jensen, Kasper Risgaard; Fojan, Peter; Jensen, Rasmus Lund; Gurevich, Leonid

    2014-02-01

    The condensation of water is a phenomenon occurring in multiple situations in everyday life, e.g., when fog is formed or when dew forms on the grass or on windows. This means that this phenomenon plays an important role within the different fields of science including meteorology, building physics, and chemistry. In this review we address condensation models and simulations with the main focus on heterogeneous condensation of water. The condensation process is, at first, described from a thermodynamic viewpoint where the nucleation step is described by the classical nucleation theory. Further, we address the shortcomings of the thermodynamic theory in describing the nucleation and emphasize the importance of nanoscale effects. This leads to the description of condensation from a molecular viewpoint. Also presented is how the nucleation can be simulated by use of molecular models, and how the condensation process is simulated on the macroscale using computational fluid dynamics. Finally, examples of hybrid models combining molecular and macroscale models for the simulation of condensation on a surface are presented.

  14. Yuriko and Michael Renardy reappointed Class of 1950 Professors

    OpenAIRE

    Owczarski, Mark

    2010-01-01

    Yuriko and Michael Renardy, professors of mathematics in the College of Science at Virginia Tech, have been reappointed as the Virginia Tech Class of 1950 Professors by the Virginia Tech Board of Visitors.

  15. Bose condensation in (random traps

    Directory of Open Access Journals (Sweden)

    V.A. Zagrebnov

    2009-01-01

    Full Text Available We study a non-interacting (perfect Bose-gas in random external potentials (traps. It is shown that a generalized Bose-Einstein condensation in the random eigenstates manifests if and only if the same occurs in the one-particle kinetic-energy eigenstates, which corresponds to the generalized condensation of the free Bose-gas. Moreover, we prove that the amounts of both condensate densities are equal. This statement is relevant for justification of the Bogoliubov approximation} in the theory of disordered boson systems.

  16. Fast mixing condensation nucleus counter

    OpenAIRE

    Flagan, Richard C.; Wang, Jian

    2003-01-01

    A fast mixing condensation nucleus counter useful for detecting particles entrained in a sample gas stream is provided. The fast mixing condensation nucleus counter comprises a detector and a mixing condensation device having a mixing chamber adapted to allow gas to flow from an inlet to an outlet, wherein the outlet directs the gas flow to the detector. The mixing chamber has an inlet for introducing vapor-laden gas into the chamber and at least one nozzle for introducing a sample gas having...

  17. Condenser assembly system for an appliance

    Energy Technology Data Exchange (ETDEWEB)

    Litch, Andrew David

    2017-10-17

    An appliance includes a compact condenser assembly formed with at least two separately and independently produced wire on tube condensers. Each of the at least two wire on tube condensers has a condenser inlet and a condenser outlet. The at least two wire on tube condensers are at least substantially locked and positioned in a matingly engaged configuration forming a compact condenser assembly. The at least two wire on tube condensers are configured to be operationally connected in at least one of a parallel configuration, a series configuration, a selectable configuration, and a bypass configuration.

  18. Efficient, Long-Life Biocidal Condenser Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Environmental control systems for manned lunar and planetary bases will require condensing heat exchangers to control humidity in manned modules. Condensing surfaces...

  19. Efficient, Long-Life Biocidal Condenser Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Environmental control systems for manned lunar and planetary bases will require condensing heat exchangers to control humidity. Condensing surfaces must be...

  20. Categorization of Quantum Mechanics Problems by Professors and Students

    Science.gov (United States)

    Lin, Shih-Yin; Singh, Chandralekha

    2010-01-01

    We discuss the categorization of 20 quantum mechanics problems by physics professors and undergraduate students from two honours-level quantum mechanics courses. Professors and students were asked to categorize the problems based upon similarity of solution. We also had individual discussions with professors who categorized the problems. Faculty…

  1. E-Mail from Professor Enhances Student Motivation and Attitudes

    Science.gov (United States)

    Legg, Angela M.; Wilson, Janie H.

    2009-01-01

    Traditionally, professors use the first day of class to build rapport. However, current technology allows professors to contact students prior to the first day of class. This study assessed how the receipt of a welcoming e-mail from a female professor 1 week before the first day of class affected student motivation and attitudes toward the…

  2. Connect and Thrive: Perspectives from a Newly Tenured Professor

    Science.gov (United States)

    Ciocchetti, Corey A.

    2011-01-01

    This essay encapsulates the author's perspective on how average professors can become highly effective professors. The author asserts that the secret rests in the ability to genuinely connect with students. Connecting really matters--even if it takes some personality adaptation and thrusts academics out of their comfort zones. Many professors fail…

  3. Anti-Fat Bias by Professors Teaching Physical Education Majors

    Science.gov (United States)

    Fontana, Fabio; Furtado, Ovande, Jr.; Mazzardo, Oldemar, Jr.; Hong, Deockki; de Campos, Wagner

    2017-01-01

    Anti-fat bias by professors in physical education departments may interfere with the training provided to pre-service teachers. The purpose of this study was to evaluate the attitudes of professors in physical education departments toward obese individuals. Professors from randomly selected institutions across all four US regions participated in…

  4. 26 CFR 509.115 - Visiting professors or teachers.

    Science.gov (United States)

    2010-04-01

    ... 26 Internal Revenue 19 2010-04-01 2010-04-01 false Visiting professors or teachers. 509.115...) REGULATIONS UNDER TAX CONVENTIONS SWITZERLAND General Income Tax § 509.115 Visiting professors or teachers. (a) General. Pursuant to Article XII of the convention, a professor or teacher, a nonresident alien who is a...

  5. Variables That Can Affect Student Ratings of Their Professors

    Science.gov (United States)

    Gotlieb, Jerry

    2013-01-01

    Attribution theory was applied to help predict the results of an experiment that examined the effects of three independent variables on students' ratings of their professors. The dependent variables were students' perceptions of whether the professor caused the students' grades and student satisfaction with their professor. The results suggest…

  6. Fundamentals of Experimental Pharmacology

    National Research Council Canada - National Science Library

    Ghosh, M

    2007-01-01

    ... to its unique approach in comparison to other books available on Experimental pharmacology. The main purpose of this book was to give a theoretical background followed by the appropriate experimental techniques. The late Prof. H. O. Schild, then Professor of Pharmacology, University College London in his brief introduction to the first editi...

  7. Solar engineering - a condensed course

    Energy Technology Data Exchange (ETDEWEB)

    Broman, Lars

    2011-11-15

    The document represents the material covered in a condensed two-week course focusing on the most important thermal and PV solar energy engineering topics, while also providing some theoretical background.

  8. Condenser procurement guidelines. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Impagliazzo, A.M.

    1985-05-01

    Steam surface condensers have a major impact on power plant availability and efficiency. Since supplying condensers to the utility industry is a very competitive buisness, it is essential that all of the requirements, all of the operating and design conditions, and any off standard conditions which can affect the condenser design and performance be clearly communicated to potential suppliers. These requirements are officially transmitted via the Purchase Specification. This report is intended to provide guidance in the preparation of this document so that it will include all of the information needed by a competent specialist to design a condenser which will achieve the required performance in a reliable manner with minimum maintenance. A further objective is to provide guidelines which will permit the Purchaser to evaluate the diverse offerings of the various suppliers.

  9. Construction of the blowdown and condensation loop

    Energy Technology Data Exchange (ETDEWEB)

    Park, Choon Kyung; Song, Chul Kyung; Cho, Seok; Chun, S. Y.; Chung, Moon Ki

    1997-12-01

    The blowdown and condensation loop (B and C loop) has been constructed to get experimental data for designing the safety depressurization system (SDS) and steam sparger which are considered to implement in the Korea Next Generation Reactor (KNGR). In this report, system description on the B and C loop is given in detail, which includes the drawings and technical specification of each component, instrumentation and control system, and the operational procedures and the results of the performance testing. (author). 7 refs., 11 tabs., 48 figs.

  10. Diffusion in condensed matter methods, materials, models

    CERN Document Server

    Kärger, Jörg

    2005-01-01

    Diffusion as the process of particle transport due to stochastic movement is a phenomenon of crucial relevance for a large variety of processes and materials. This comprehensive, handbook- style survey of diffusion in condensed matter gives detailed insight into diffusion as the process of particle transport due to stochastic movement. Leading experts in the field describe in 23 chapters the different aspects of diffusion, covering microscopic and macroscopic experimental techniques and exemplary results for various classes of solids, liquids and interfaces as well as several theoretical concepts and models. Students and scientists in physics, chemistry, materials science, and biology will benefit from this detailed compilation.

  11. Dissipative phenomena in condensed matter some applications

    CERN Document Server

    Dattagupta, Sushanta

    2004-01-01

    From the field of nonequilibrium statistical physics, this graduate- and research-level volume treats the modeling and characterization of dissipative phenomena. A variety of examples from diverse disciplines like condensed matter physics, materials science, metallurgy, chemical physics etc. are discussed. Dattagupta employs the broad framework of stochastic processes and master equation techniques to obtain models for a wide range of experimentally relevant phenomena such as classical and quantum Brownian motion, spin dynamics, kinetics of phase ordering, relaxation in glasses, dissipative tunneling. It provides a pedagogical exposition of current research material and will be useful to experimentalists, computational physicists and theorists.

  12. Spotlight on CERN : Professor Michel Spiro

    CERN Multimedia

    CERN video productions

    2011-01-01

    20 Member states throughout Europe. A geographical expansion underway. A worldwide, international collaboration and a scientific challenge on a scale second to none. In view of this complexity, how is CERN managed? This is the remit of the CERN council, which notably defines the strategic programmes, annual objectives, approves the annual budget and nominates the directorate. I am pleased to welcome Professor Michel Spiro, scientific director of the CNRS in France and CERN Council presdient since 2010. On today’s agenda: Expansion, innovation and communication. Hello and welcome Professor.. François et Stéphan are of course with me today to discuss such matters as antimatter, press and we will also be talking water and towers… I will say no more. It’s good to see you both ! And welcome to you all for this latest edition of Spotlight on CERN.

  13. Use of fundamental condensation heat transfer experiments for the development of a sub-grid liquid jet condensation model

    Energy Technology Data Exchange (ETDEWEB)

    Buschman, Francis X., E-mail: Francis.Buschman@unnpp.gov; Aumiller, David L.

    2017-02-15

    Highlights: • Direct contact condensation data on liquid jets up to 1.7 MPa in pure steam and in the presence of noncondensable gas. • Identified a pressure effect on the impact of noncondensables to suppress condensation heat transfer not captured in existing data or correlations. • Pure steam data is used to develop a new correlation for condensation heat transfer on subcooled liquid jets. • Noncondensable data used to develop a modification to the renewal time estimate used in the Young and Bajorek correlation for condensation suppression in the presence of noncondensables. • A jet injection boundary condition, using a sub-grid jet condensation model, is developed for COBRA-IE which provides a more detailed estimate of the condensation rate on the liquid jet and allows the use of jet specific closure relationships. - Abstract: Condensation on liquid jets is an important phenomenon for many different facets of nuclear power plant transients and analyses such as containment spray cooling. An experimental facility constructed at the Pennsylvania State University, the High Pressure Liquid Jet Condensation Heat Transfer facility (HPLJCHT), has been used to perform steady-state condensation heat transfer experiments in which the temperature of the liquid jet is measured at different axial locations allowing the condensation rate to be determined over the jet length. Test data have been obtained in a pure steam environment and with varying concentrations of noncondensable gas. This data extends the available jet condensation data from near atmospheric pressure up to a pressure of 1.7 MPa. An empirical correlation for the liquid side condensation heat transfer coefficient has been developed based on the data obtained in pure steam. The data obtained with noncondensable gas were used to develop a correlation for the renewal time as used in the condensation suppression model developed by Young and Bajorek. This paper describes a new sub-grid liquid jet

  14. 31 July 2014 - Professor M. Kastner

    CERN Multimedia

    Egli, Laurent

    2014-01-01

    MIT Faculty Member Donner Professor of Physics Massachusetts Institute of Technology United States of America, Prof. M. Kastner visiting the LHC tunnel at Point 5 with Beams Department M. Solfaroli Camillocci, LHC superconducting magnet assembly hall visit with L. Rossi and R. Principe, LHC Computing Grid Project presentation and computer centre visit with I. Bird and signing the guest book with CERN Director-General R. Heuer.

  15. [Homage to Professor Dr. Nicasio Etchepareborda].

    Science.gov (United States)

    1998-11-01

    During a solemn academic act, de Main Classroom of the Facultad de Odontologia de Buenos Aires was named after Prof. Dr. Nicasio Etchepareborda. He has been the first professor at the Escuela de Odontologia and its organizer, after having obtained his Dentistry degree at the Dental School of Paris, in 1882. The new school was founded in 1891, and its activities began the following year.

  16. In memory of Professor Paolo Talamucci

    Directory of Open Access Journals (Sweden)

    Cantiani M

    2010-05-01

    Full Text Available Paolo Talamucci, Full Professor of Range Management at the Università degli Studi in Florence from 1975 to 2001, passed away on 27th November 2009, after a brief and unrelenting illness. Professor Talamucci spent many long years in the field of research, in both Mediterranean and Alpine regions. His research, profoundly rooted in the territory he was studying, holistic in its approach and rigorously scientific, was characterized by a strong interdisciplinary element, seeking always to take into account the totality of the components of the ecosystem. Professor Talamucci was one of the first scholars of the pastoral system to highlight the problems related to the abandonment of traditional animal husbandry in mountainous zones and to look for ways to counteract the undesirable transformation of the landscape and the consequent loss of biodiversity. His curriculum and his numerous scientific publications bear testimony not only to the prestigious research institutes, world-wide, with which he was associated, but also to the important international dimension of his research.

  17. APOSENTADORIA: como professores vivenciam este momento?

    Directory of Open Access Journals (Sweden)

    Cristiane Nervis Conrado Machado

    2017-05-01

    Full Text Available O presente artigo buscou compreender as implicações que a aposentadoria causa na vida de professores, levando em conta o significado que a aposentadoria representa à estes, considerando os pontos de maior mudança após a aposentadoria, bem como os aspectos positivos e negativos causados pela aposentadoria na percepção dos sujeitos da pesquisa. Para tanto, foi realizada uma pesquisa qualitativa caracterizada como exploratória e descritiva com professores aposentados por mais de dois anos, com idade entre 58 e 66 anos, através de entrevistas individuais, com roteiros semiestruturados. A análise dos dados foi por meio da análise de conteúdo de Bardin (2011. Entre os principais resultados, destaca-se o significado de “liberdade” que a aposentadoria representa, a rotina como maior mudança e flexibilidade de horários dentre os pontos positivos e a falta dos alunos como aspecto negativo, contudo, pode-se perceber que a aposentadoria possibilitou e contribuiu para que os professores pudessem desfrutar de momentos de lazer, dedicando cuidado à família e realizando seus anseios e vontades.

  18. More accurate theory for Bose-Einstein condensation fraction

    Energy Technology Data Exchange (ETDEWEB)

    Biswas, Shyamal [Department of Theoretical Physics, Indian Association for the Cultivation of Science Jadavpur, Kolkata-700032 (India)], E-mail: tpsb@iacs.res.in

    2008-03-03

    Bose-Einstein statistics is derived in the thermodynamic limit when the ratio of system size to thermal de Broglie wavelength goes to infinity. However, according to the experimental setup of Bose-Einstein condensation of harmonically trapped Bose gas of alkali atoms, the ratio near the condensation temperature (T{sub o}) is 30-50. And, at ultralow temperatures well below T{sub o}, this ratio becomes comparable to 1. We argue that finite size as well as the ultralow temperature induces corrections to Bose-Einstein statistics. From the corrected statistics we plot condensation fraction versus temperature graph. This theoretical plot satisfies well with the experimental plot [A. Griesmaier et al., Phys. Rev. Lett. 94 (2005) 160401].

  19. Stable switching among high-order modes in polariton condensates

    Science.gov (United States)

    Sun, Yongbao; Yoon, Yoseob; Khan, Saeed; Ge, Li; Steger, Mark; Pfeiffer, Loren N.; West, Ken; Türeci, Hakan E.; Snoke, David W.; Nelson, Keith A.

    2018-01-01

    We report multistate optical switching among high-order bouncing-ball modes ("ripples") and whispering-gallery modes ("petals") of exciton-polariton condensates in a laser-generated annular trap. By tailoring the diameter and power of the annular trap, the polariton condensate can be switched among different trapped modes, accompanied by redistribution of spatial densities and superlinear increase in the emission intensities, implying that polariton condensates in this geometry could be exploited for an all-optical multistate switch. A model based on non-Hermitian modes of the generalized Gross-Pitaevskii equation reveals that this mode switching arises from competition between pump-induced gain and in-plane polariton loss. The parameters for reproducible switching among trapped modes have been measured experimentally, giving us a phase diagram for mode switching. Taken together, the experimental result and theoretical modeling advance our fundamental understanding of the spontaneous emergence of coherence and move us toward its practical exploitation.

  20. A comparison between the toxicity of oil and condensate

    Energy Technology Data Exchange (ETDEWEB)

    Foekema, E.; Schobben, H.P.M.; Marquenie, J.; Scholten, M.C.T. [TNO, Den Helder (Netherlands). Lab. for Applied Marine Research

    1995-12-31

    The toxicity of condensate from the `Ameland` gasfield was compared to the toxicity of the standard North Sea oil `Forties`. The comparison was based on the `topped` (residue after distillation at 200 C) fraction. This fraction is comparable with the fraction of the oil that is hazardous to the marine environment because the topped fraction will almost immediately evaporate. Hundred individuals of Corophium were placed in experimental systems with a surface of 500 CM{sup 2} filled with 10 cm sediment and 15 cm of water from the Wadden Sea. After two days the oil and condensate were added to the water surface in concentrations between 100 {micro}g/m{sup 2} to 100 {micro}g/m{sup 2}. After application a low tide was simulated until the oil or condensate covered the sediment. After five hours the sediment was inundated again. After three days the survival of the individuals and the remaining concentrations of oil and condensate in sediment were measured. From video images taken directly after application of the oil it can be seen that the Corophiums crept out of the polluted sediment. Despite the fact that the topped condensate contained much more lower alkanes, almost no difference was found between the toxicity of the topped oil and condensate. This leads to the conclusion that the effect of oil is mainly based on physical damage and not so much on the composition. The results of a later experiment with sunflower oil confirmed this conclusion.

  1. Research progress of control of condensate depression for condenser

    Science.gov (United States)

    Liu, Ying; Liang, Run; Li, Fengyu

    2017-08-01

    It is introduced that significance and structure of the condensate depression control system. In accordance with controller devised procedure, we analyze and elaborate how to construct the lumped parameter and dynamic mathematical model which possesses distinct physics significance. Neural network model being called black-box model is also introduced. We analyze and contrast the control technique of condensate depression as conventional PI control, fuzzy PI control and fuzzy control. It is indicated that if the controller of condensate depression were devised inappropriate, while the steam discharged of turbine varying by a large margin, would result in the rotation rate of cooling water circulating pump accelerating at a great lick even to trigger the galloping danger which is less impressive for the units operating safely.

  2. TRACE assessment on local condensation heat transfer in presence of non-condensable gas inside a vertical tube

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Yong Jin; Ahn, Seung Hoon; Kim, Kap; Kim, Hho Jung [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of)

    2009-07-01

    TRACE assessment was performed to investigate local condensation heat transfer coefficients in the presence of a noncondensable gas inside a vertical tube. The data obtained from pure steam and steam/nitrogen mixture condensation experiments were compared to study the effects of noncondensable nitrogen gas on the annular film condensation phenomena. The condenser tube had a small inner diameter of 13mm (about 1/2-in.) and this experiment had been performed to prove the effectiveness of the a Passive Residual Heat Removal System (PRHRS) of SMART (System-integrated Modular Advanced ReacTor), which is a small modular integral-type pressurized water reactor that is developed for the dual purposes of seawater desalination and small-scaled power generation. In the case of nitrogen presence, TRACE results show the converged results but the prediction is different from experimental data. The candidate reasons can be focused on several models, such as the film thickness calculation, surface area, and condensation heat transfer correlations, etc. In the case of pure steam condensation case, TRACE results shows large oscillations and do not converge. This should be investigated in detail to identify the reason. Until now, the oscillation in thermal hydraulic parameters results from the film thickness calculation and surface area calculation. For future works, the whole sets of the experiment will be assessed and the improvement of TRACE will be performed.

  3. Visit of Professor Shigehiko Hasumi. President of Tokyo University, Japan, Professor Kazuo Okamoto, Head of Graduate School of Mathematical Sciences, Professor Toshiteru Matsuura, Head of Graduate School of Arts and Sciences

    CERN Multimedia

    Patrice Loiez

    1999-01-01

    Visit of Professor Shigehiko Hasumi. President of Tokyo University, Japan, Professor Kazuo Okamoto, Head of Graduate School of Mathematical Sciences, Professor Toshiteru Matsuura, Head of Graduate School of Arts and Sciences

  4. Chiral magnetic effect in condensed matter systems

    Science.gov (United States)

    Li, Qiang; Kharzeev, Dmitri E.

    2016-12-01

    The chiral magnetic effect (CME) is the generation of electrical current induced by chirality imbalance in the presence of magnetic field. It is a macroscopic manifestation of the quantum chiral anomaly [S. L. Adler. Axial-vector vertex in spinor electrodynamics. Physical Review, 177, 2426 (1969), J. S. Bell and R. Jackiw. A PCAC puzzle: π 0 γγin the σ-model. Il Nuovo Cimento A, 60, 47-61 (1969)] in systems possessing charged chiral fermions. In quark-gluon plasma containing nearly massless quarks, the chirality imbalance is sourced by the topological transitions. In condensed matter systems, the chiral quasiparticles emerge in gapless semiconductors with two energy bands having pointlike degeneracies opening the path to the study of chiral anomaly [H. B. Nielsen and M. Ninomiya. The Adler-Bell-Jackiw anomaly and Weyl fermions in a crystal. Physics Letters B, 130, 389-396 (1983)]. Recently, these novel materials - so-called Dirac and Weyl semimetals have been discovered experimentally, are suitable for the investigation of the CME in condensed matter experiments. Here we report on the first experimental observation of the CME in a 3D Dirac semimetal ZrTe5 [Q. Li, D. E. Kharzeev, C. Zhang, Y. Huang, I. Pletikosić, A. V. Fedorov, R. D. Zhong, J. A. Schneeloch, G. D. Gu, and T. Valla. Chiral magnetic effect in ZrTe5. Nature Physics (2016) doi:10.1038/nphys3648].

  5. Charged ρ Meson Condensate in Neutron Stars within RMF Models

    Directory of Open Access Journals (Sweden)

    Konstantin A. Maslov

    2017-12-01

    Full Text Available Knowledge of the equation of state (EoS of cold and dense baryonic matter is essential for the description of properties of neutron stars (NSs. With an increase of the density, new baryon species can appear in NS matter, as well as various meson condensates. In previous works, we developed relativistic mean-field (RMF models with hyperons and Δ -isobars, which passed the majority of known experimental constraints, including the existence of a 2 M ⊙ neutron star. In this contribution, we present results of the inclusion of ρ − -meson condensation into these models. We have shown that, in one class of the models (so-called KVOR-based models, in which the additional stiffening procedure is introduced in the isoscalar sector, the condensation gives only a small contribution to the EoS. In another class of the models (MKVOR-based models with additional stiffening in isovector sector, the condensation can lead to a first-order phase transition and a substantial decrease of the NS mass. Nevertheless, in all resulting models, the condensation does not spoil the description of the experimental constraints.

  6. Holography, Gravity and Condensed Matter

    Energy Technology Data Exchange (ETDEWEB)

    Hartnoll, Sean [Stanford Univ., CA (United States). Dept. of Physics

    2017-12-20

    Over the five years of funding from this grant, I produced 26 publications. These include a book-long monograph on "Holographic Quantum Matter" that is currently in press with MIT press. The remainder were mostly published in Physical Review Letters, the Journal of High Energy Physics, Nature Physics, Classical and Quantum Gravity and Physical Review B. Over this period, the field of holography applied to condensed matter physics developed from a promising theoretical approach to a mature conceptual and practical edifice, whose ideas were realized in experiments. My own work played a central role in this development. In particular, in the final year of this grant, I co-authored two experimental papers in which ideas that I had developed in earlier years were shown to usefully describe transport in strongly correlated materials — these papers were published in Science and in the Proceedings of the National Academy of Sciences (obviously my contribution to these papers was theoretical). My theoretical work in this period developed several new directions of research that have proven to be influential. These include (i) The construction of highly inhomogeneous black hole event horizons, realizing disordered fixed points and describing new regimes of classical gravity, (ii) The conjecture of a bound on diffusivities that could underpin transport in strongly interacting media — an idea which may be proven in the near future and has turned out to be intimately connected to studies of quantum chaos in black holes and strongly correlated media, (iii) The characterization of new forms of hydrodynamic transport, e.g. with phase-disordered order parameters. These studies pertain to key open questions in our understanding of how non-quasiparticle, intrinsically strongly interacting systems can behave. In addition to the interface between holography and strongly interacting condensed matter systems, I made several advances on understanding the role of entanglement in quantum

  7. Narratividade do professor: mediação e linguagem na sala de aula

    Directory of Open Access Journals (Sweden)

    Isabel Maganin Chesini

    2013-10-01

    Full Text Available OBJETIVO: construir e analisar uma experiência de formação do professor em sua narratividade e os efeitos da mesma na narratividade das crianças. MÉTODO: a amostra se constituiu de duas professoras de pré-escola, 28 alunos, 14 de cada professora sendo, um grupo experimental e o outro grupo controle, e os pais das crianças como controle ambiental. As avaliações foram feitas a partir de sessões de filmagem das professoras, coleta das narrativas das crianças e questionário sobre como desenvolviam a atividade de contar em casa. RESULTADOS: o processo de mediação fonoaudiólogo/professor, com enfoque na narrativa, provocou mudança no modo de narrar não só do professor, mas também nas categorias narrativas das crianças, demonstrando a importância de o profissional que assessore o professor em sua prática trazendo novos subsídios teóricos. CONCLUSÃO: após a realização desta pesquisa observou-se que a Experiência de Aprendizagem Mediada (EAM e os princípios interacionistas sobre a aquisição da linguagem e o desenvolvimento narrativo foram efetivos na construção de uma experiência formativa do professor para melhorar sua narratividade e que a evolução do professor se refletiu na evolução das habilidades narrativas das crianças.

  8. Interplay of weak interactions in the atom-by-atom condensation of xenon within quantum boxes

    NARCIS (Netherlands)

    Nowakowska, Sylwia; Wäckerlin, Aneliia; Kawai, Shigeki; Ivas, Toni; Nowakowski, Jan; Fatayer, Shadi; Wäckerlin, Christian; Nijs, Thomas; Meyer, Ernst; Björk, Jonas; Stöhr, Meike; Gade, Lutz H.; Jung, Thomas A.

    2015-01-01

    Condensation processes are of key importance in nature and play a fundamental role in chemistry and physics. Owing to size effects at the nanoscale, it is conceptually desired to experimentally probe the dependence of condensate structure on the number of constituents one by one. Here we present an

  9. Skyrmions in a ferromagnetic Bose−Einstein condensate

    NARCIS (Netherlands)

    Al Khawaja, U.; Stoof, H.T.C.

    2001-01-01

    Multi-component Bose-Einstein condensates provide opportunities to explore experimentally the wealth of physics associated with the spin degrees of freedom. The ground-state properties and line-like vortex excitations of these quantum systems have been studied theoretically. In principle,

  10. Bose–Einstein condensation: Where many become one and ...

    Indian Academy of Sciences (India)

    Abstract. Bose–Einstein condensation and superfluidity are well known to occur in the dilute gaseous as well as in the dense liquid state of matter having a fixed number of. Bose particles. Very recently, experimental evidence has been obtained for the probable realization of BEC and superfluidity in 4He in the solid state ...

  11. Bose–Einstein condensation: Where many become one and ...

    Indian Academy of Sciences (India)

    Bose–Einstein condensation and superfluidity are well known to occur in the dilute gaseous as well as in the dense liquid state of matter having a fixed number of Bose particles. Very recently, experimental evidence has been obtained for the probable realization of BEC and superfluidity in 4He in the solid state too, ...

  12. Electric condensation of divalent counterions by humic acid nanoparticles

    NARCIS (Netherlands)

    Leeuwen, van H.P.; Town, R.M.

    2016-01-01

    Experimental data for divalent counterion binding by soil humic acid nanoparticles are set against ion distributions as ensuing from continuous Poisson–Boltzmann electrostatics and a two-state condensation approach. The results demonstrate that Poisson–Boltzmann massively underestimates the extent

  13. Exploring dynamic localization with a Bose-Einstein condensate

    OpenAIRE

    Eckardt, Andre; Holthaus, Martin; Lignier, Hans; Zenesini, Alessandro; Ciampini, Donatella; Morsch, Oliver; Arimondo, Ennio

    2008-01-01

    We report on the experimental observation of dynamic localization of a Bose-Einstein condensate in a shaken optical lattice, both for sinusoidal and square-wave forcing. The formulation of this effect in terms of a quasienergy band collapse, backed by the excellent agreement of the observed collapse points with the theoretical predictions, suggests the feasibility of systematic quasienergy band engineering.

  14. Exploring the thermodynamics of Bose-Einstein condensation in a homogeneous atomic gas

    Science.gov (United States)

    Schmidutz, Tobias; Gotlibovych, Igor; Gaunt, Alexander; Smith, Robert; Hadzibabic, Zoran

    2013-05-01

    Atomic Bose-Einstein condensates have traditionally been produced in harmonic traps and only very recently it became possible to attain condensation in a homogeneous gas [A.L. Gaunt et al., arXiv:1212.4453]. In this talk we will present our new experimental results on the thermodynamics of condensation in a homogeneous weakly interacting Bose gas. We perform a systematic study of the tuning of the critical temperature with system parameters, the saturation of the thermal components in a partially condensed sample, and the total energy of the gas. We also study the dynamics of cooling in a uniform gas.

  15. The microscopic dynamics of condensed parahydrogen

    CERN Document Server

    Celli, M; Colognesi, D

    2002-01-01

    We have measured the almost-pure incoherent scattering function of liquid and solid parahydrogen, using inelastic neutron scattering. The experiments were carried out on TOSCA, a time-of-flight, inverse-geometry, crystal-analyzer spectrometer, operating on the pulsed neutron source at ISIS (UK). The experiments have been planned taking advantage of the intrinsic incoherence introduced in the scattering process by the rotational transitions. The measured double-differential cross section gives a direct experimental access to the microscopic dynamics of condensed hydrogen. From the high-energy region of the spectrum, where the impulse approximation for the center of mass motion applies, we have been able to extract the translational mean kinetic energy. In the low-energy region, using the Gaussian approximation, we compare the experimental data in the liquid phase with the results of a model for the velocity autocorrelation function. The results are encouraging, but suggest further work. (orig.)

  16. Spacecraft Crew Cabin Condensation Control

    Science.gov (United States)

    Carrillo, Laurie Y.; Rickman, Steven L.; Ungar, Eugene K.

    2013-01-01

    A report discusses a new technique to prevent condensation on the cabin walls of manned spacecraft exposed to the cold environment of space, as such condensation could lead to free water in the cabin. This could facilitate the growth of mold and bacteria, and could lead to oxidation and weakening of the cabin wall. This condensation control technique employs a passive method that uses spacecraft waste heat as the primary wallheating mechanism. A network of heat pipes is bonded to the crew cabin pressure vessel, as well as the pipes to each other, in order to provide for efficient heat transfer to the cabin walls and from one heat pipe to another. When properly sized, the heat-pipe network can maintain the crew cabin walls at a nearly uniform temperature. It can also accept and distribute spacecraft waste heat to maintain the pressure vessel above dew point.

  17. Introduction. Cosmology meets condensed matter.

    Science.gov (United States)

    Kibble, T W B; Pickett, G R

    2008-08-28

    At first sight, low-temperature condensed-matter physics and early Universe cosmology seem worlds apart. Yet, in the last few years a remarkable synergy has developed between the two. It has emerged that, in terms of their mathematical description, there are surprisingly close parallels between them. This interplay has been the subject of a very successful European Science Foundation (ESF) programme entitled COSLAB ('Cosmology in the Laboratory') that ran from 2001 to 2006, itself built on an earlier ESF network called TOPDEF ('Topological Defects: Non-equilibrium Field Theory in Particle Physics, Condensed Matter and Cosmology'). The articles presented in this issue of Philosophical Transactions A are based on talks given at the Royal Society Discussion Meeting 'Cosmology meets condensed matter', held on 28 and 29 January 2008. Many of the speakers had participated earlier in the COSLAB programme, but the strength of the field is illustrated by the presence also of quite a few new participants.

  18. Scrutinizing the pion condensed phase

    Energy Technology Data Exchange (ETDEWEB)

    Carignano, Stefano; Mammarella, Andrea; Mannarelli, Massimo [INFN, Laboratori Nazionali del Gran Sasso, Assergi (Italy); Lepori, Luca [Universita di Padova, Dipartimento di Fisica e Astronomia, Padova (Italy); Universita dell' Aquila, Dipartimento di Scienze Fisiche e Chimiche, Coppito-L' Aquila (Italy); Pagliaroli, Giulia [INFN, Laboratori Nazionali del Gran Sasso, Assergi (Italy); Gran Sasso Science Institute, L' Aquila (Italy)

    2017-02-15

    When the isospin chemical potential exceeds the pion mass, charged pions condense in the zero-momentum state forming a superfluid. Chiral perturbation theory provides a very powerful tool for studying this phase. However, the formalism that is usually employed in this context does not clarify various aspects of the condensation mechanism and makes the identification of the soft modes problematic. We re-examine the pion condensed phase using different approaches within the chiral perturbation theory framework. As a first step, we perform a low-density expansion of the chiral Lagrangian valid close to the onset of the Bose-Einstein condensation. We obtain an effective theory that can be mapped to a Gross-Pitaevskii Lagrangian in which, remarkably, all the coefficients depend on the isospin chemical potential. The low-density expansion becomes unreliable deep in the pion condensed phase. For this reason, we develop an alternative field expansion deriving a low-energy Lagrangian analog to that of quantum magnets. By integrating out the ''radial'' fluctuations we obtain a soft Lagrangian in terms of the Nambu-Goldstone bosons arising from the breaking of the pion number symmetry. Finally, we test the robustness of the second-order transition between the normal and the pion condensed phase when next-to-leading-order chiral corrections are included. We determine the range of parameters for turning the second-order phase transition into a first-order one, finding that the currently accepted values of these corrections are unlikely to change the order of the phase transition. (orig.)

  19. Heat Transfer Enhancement During Water and Hydrocarbon Condensation on Lubricant Infused Surfaces.

    Science.gov (United States)

    Preston, Daniel J; Lu, Zhengmao; Song, Youngsup; Zhao, Yajing; Wilke, Kyle L; Antao, Dion S; Louis, Marcel; Wang, Evelyn N

    2018-01-11

    Vapor condensation is routinely used as an effective means of transferring heat or separating fluids. Dropwise condensation, where discrete droplets form on the condenser surface, offers a potential improvement in heat transfer of up to an order of magnitude compared to filmwise condensation, where a liquid film covers the surface. Low surface tension fluid condensates such as hydrocarbons pose a unique challenge since typical hydrophobic condenser coatings used to promote dropwise condensation of water often do not repel fluids with lower surface tensions. Recent work has shown that lubricant infused surfaces (LIS) can promote droplet formation of hydrocarbons. In this work, we confirm the effectiveness of LIS in promoting dropwise condensation by providing experimental measurements of heat transfer performance during hydrocarbon condensation on a LIS, which enhances heat transfer by ≈450% compared to an uncoated surface. We also explored improvement through removal of noncondensable gases and highlighted a failure mechanism whereby shedding droplets depleted the lubricant over time. Enhanced condensation heat transfer for low surface tension fluids on LIS presents the opportunity for significant energy savings in natural gas processing as well as improvements in thermal management, heating and cooling, and power generation.

  20. Religiosidade em alunos e professores portugueses

    OpenAIRE

    Ferreira, Ana Maria Mendes dos Santos Veríssimo

    2005-01-01

    Tese de Doutoramento em Ciências da Educação na especialidade de Educação Intercultural apresentada à Universidade Aberta Esta tese pretende analisar a religiosidade em alunos e professores, sendo a religiosidade entendida como o grau de ligação ou aceitação que cada indivíduo tem face à instituição religiosa (Alston, 1875) e à forma como põe em prática as crenças e os rituais (Shafranske e Malony, 1990). Para medir a religiosidade foram utilizados diversos instrumentos – a escala de Atitu...

  1. Professor Stewart's hoard of mathematical treasures

    CERN Document Server

    Stewart, Ian

    2010-01-01

    Ian Stewart, author of the bestselling Professor Stewart's Cabinet of Mathematical Curiosities, presents a new and magical mix of games, puzzles, paradoxes, brainteasers, and riddles. He mingles these with forays into ancient and modern mathematical thought, appallingly hilarious mathematical jokes, and enquiries into the great mathematical challenges of the present and past. Amongst a host of arcane and astonishing facts about every kind of number from irrational or imaginary to complex or cuneiform, we find out: how to organise chaos; how matter balances anti-matter; how to turn a sphere i

  2. Boodskap van Professor Dr. J. Waterink

    Directory of Open Access Journals (Sweden)

    J. Waterink

    1955-03-01

    Full Text Available Boodskap van Professor Dr. J. Waterinkter gelegendheid van die verlening aan hem van de graad Doctor Educationis, honoris causa, door de Universiteit voor Christelijk Hoger Onderwijs te Potchefstroom op Zaterdag, 26 Maart 1955, en op die dag voorgelezen door de heer Jan van den Berg, Buitengewoon en Gevolmachtigd Ambassadeur van Hare Mi iesteit de Koningin der Nederlanden. Mijnheer, de Kanselier, Mijnheer de Voorzitter van de Raad, Mijnheer deVice-Kanselier en Rector, overige Heren ambtsdragers, en gij alien,die herwaarts kwaanit ter gelegenheid van deze Gradendag,zeer geachte en zeer gewenste toehoorders.

  3. On the onset of surface condensation: formation and transition mechanisms of condensation mode.

    Science.gov (United States)

    Sheng, Qiang; Sun, Jie; Wang, Qian; Wang, Wen; Wang, Hua Sheng

    2016-08-02

    Molecular dynamics simulations have been carried out to investigate the onset of surface condensation. On surfaces with different wettability, we snapshot different condensation modes (no-condensation, dropwise condensation and filmwise condensation) and quantitatively analyze their characteristics by temporal profiles of surface clusters. Two different types of formation of nanoscale droplets are identified, i.e. the formations with and without film-like condensate. We exhibit the effect of surface tensions on the formations of nanoscale droplets and film. We reveal the formation mechanisms of different condensation modes at nanoscale based on our simulation results and classical nucleation theory, which supplements the 'classical hypotheses' of the onset of dropwise condensation. We also reveal the transition mechanism between different condensation modes based on the competition between surface tensions and reveal that dropwise condensation represents the transition states from no-condensation to filmwise condensation.

  4. Winding up superfluid in a torus via Bose Einstein condensation

    Energy Technology Data Exchange (ETDEWEB)

    Das, Arnab [Los Alamos National Laboratory; Sabbatini, Jacopo [Los Alamos National Laboratory; Zurek, Wojciech H [Los Alamos National Laboratory

    2010-12-16

    We simulate Bose-Einstein condensation at finite temperature in a ring employing stochastic Gross-Pitaevskii equation and show that cooling through the critical point can generate topologically stable quantized circulation of the newborn condensate around the ring. The resulting winding numbers exhibiting Gaussian distribution with dispersion following scaling behavior predicted by the Kibble-Zurek mechanism (KZM). This opens up possibilities for direct experimental study of the underlying phase transition and the basic principles of KZM extended to account for such circulations. We discuss the effect of inhomogeneity on the above phenomenon by considering the effect of tilting of the ring in the gravitational field.

  5. Condensation analysis of water vapour in the presence of inert gas(ses) for the CO2 capture

    OpenAIRE

    Sivalingam, S.;Raindl, M.;Gleis, S.;Spliethoff, H.

    2017-01-01

    The vapour in oxy fuel combustion flue gasses can be condensed using an atmospheric condenser in order to separate and capture the CO2. The conditions of heat transfer are considerably impaired in the presence of non-condensable gasses e.g.CO2, and the over all heat transfer coefficient is drastically reduced when compared to that of the pure vapour. The presented experimental works are conducted to determine the effects of CO2 and N2 as non-condensable gasses in the condensation heat transfe...

  6. On the onset of surface condensation: formation and transition mechanisms of condensation mode

    OpenAIRE

    Qiang Sheng; Jie Sun; Qian Wang; Wen Wang; Hua Sheng Wang

    2016-01-01

    Molecular dynamics simulations have been carried out to investigate the onset of surface condensation. On surfaces with different wettability, we snapshot different condensation modes (no-condensation, dropwise condensation and filmwise condensation) and quantitatively analyze their characteristics by temporal profiles of surface clusters. Two different types of formation of nanoscale droplets are identified, i.e. the formations with and without film-like condensate. We exhibit the effect of ...

  7. Improved Cloud Condensation Nucleus Spectrometer

    Science.gov (United States)

    Leu, Ming-Taun

    2010-01-01

    An improved thermal-gradient cloud condensation nucleus spectrometer (CCNS) has been designed to provide several enhancements over prior thermal- gradient counters, including fast response and high-sensitivity detection covering a wide range of supersaturations. CCNSs are used in laboratory research on the relationships among aerosols, supersaturation of air, and the formation of clouds. The operational characteristics of prior counters are such that it takes long times to determine aerosol critical supersaturations. Hence, there is a need for a CCNS capable of rapid scanning through a wide range of supersaturations. The present improved CCNS satisfies this need. The improved thermal-gradient CCNS (see Figure 1) incorporates the following notable features: a) The main chamber is bounded on the top and bottom by parallel thick copper plates, which are joined by a thermally conductive vertical wall on one side and a thermally nonconductive wall on the opposite side. b) To establish a temperature gradient needed to establish a supersaturation gradient, water at two different regulated temperatures is pumped through tubes along the edges of the copper plates at the thermally-nonconductive-wall side. Figure 2 presents an example of temperature and supersaturation gradients for one combination of regulated temperatures at the thermally-nonconductive-wall edges of the copper plates. c) To enable measurement of the temperature gradient, ten thermocouples are cemented to the external surfaces of the copper plates (five on the top plate and five on the bottom plate), spaced at equal intervals along the width axis of the main chamber near the outlet end. d) Pieces of filter paper or cotton felt are cemented onto the interior surfaces of the copper plates and, prior to each experimental run, are saturated with water to establish a supersaturation field inside the main chamber. e) A flow of monodisperse aerosol and a dilution flow of humid air are introduced into the main

  8. Correlations in condensed matter under extreme conditions a tribute to Renato Pucci on the occasion of his 70th birthday

    CERN Document Server

    2017-01-01

    This book addresses a wide range of topics relating to the properties and behavior of condensed matter under extreme conditions such as intense magnetic and electric fields, high pressures, heat and cold, and mechanical stresses. It is divided into four sections devoted to condensed matter theory, molecular chemistry, theoretical physics, and the philosophy and history of science. The main themes include electronic correlations in material systems under extreme pressure and temperature conditions, surface physics, the transport properties of low-dimensional electronic systems, applications of the density functional theory in molecular systems, and graphene. The book is the outcome of a workshop held at the University of Catania, Italy, in honor of Professor Renato Pucci on the occasion of his 70th birthday. It includes selected invited contributions from collaborators and co-authors of Professor Pucci during his long and successful career, as well as from other distinguished guest authors.

  9. Habitus professoral na sala de aula virtual

    Directory of Open Access Journals (Sweden)

    Alexandre Marinho Pimenta

    2014-09-01

    Full Text Available Entendendo que a indiferença na ação pedagógica contribui para a reprodução das desigualdades no sistema de ensino, o presente artigo busca captar, a partir de entrevistas semiestruturadas, traços do habitus de professores supervisores de disciplinas do curso de Licenciatura em Pedagogia na modalidade a distância na Universidade de Brasília - UnB no âmbito do Sistema Universidade Aberta do Brasil - UAB. As orientações metodológicas de Bourdieu (2007 foram um dos elementos orientadores na análise das entrevistas, considerando ainda o uso heurístico do conceito de habitus. Conclui-se que o habitus professoral envolve esforços voluntários em busca de uma ação pedagógica diferenciada. No entanto, ele é ambíguo e condescendente frente aos limites do modelo de EaD no âmbito da UAB. Ao fim, os dados analisados permitem fornecer elementos para reorientação político-pedagógica que vise a um novo modelo de EaD nacional.

  10. Entrevista com o professor Salomon Turnowski

    Directory of Open Access Journals (Sweden)

    Carolina Lima Vilela

    2014-01-01

    Full Text Available Com aproximadamente 50 anos de experiências profissionais variadas em Geografia, o Professor Salomon Turnowski se revela, até hoje, um apaixonado por nosso campo de conhecimento. Em entrevista realizada pela equipe da Revista Giramundo, em junho de 2009, na Unidade Escolar Humaitá II, a disposição de contar sua trajetória parece movida pelos comentários a respeito de nossa ciência, de suas transformações e de sua paixão pelos livros. Atuante no Colégio Pedro II, onde lecionou entre 1984 e 2009, no IBGE e na antiga FIDERJ (Fundação Instituto de Desenvolvimento do Estado do Rio de Janeiro, entre outros, seu depoimento se revela, portanto, uma oportunidade para conhecer um pouco mais sobre sujeitos e instituições voltados à construção da Geografia no Brasil e no Rio de Janeiro, assim como sobre os contrastes entre as vivências de geógrafos e de professor. Fica aqui o registro acerca da experiência valiosa e diversificada desse profissional, assim como uma singela homenagem.

  11. Entrevista com o professor Rafael Straforini

    Directory of Open Access Journals (Sweden)

    Demian Garcia Castro

    2015-07-01

    Full Text Available Com vivência profissional na Educação Básica e na Superior, além de experiência de pesquisa em diferentes instituições universitárias nos estados de São Paulo e do Rio de Janeiro, o professor Rafael Straforini pode ser considerado uma das novas vozes importantes na área do Ensino de Geografia. Assim como na edição anterior, uma vez mais utilizamo-nos de plataforma digital e, na conexão direta Rio-Campinas, tivemos a oportunidade de abordar questões como a Geografia na Educação Infantil e nas séries iniciais do Ensino Fundamental, o currículo e a formação de professores, além de aproveitar um pouco para conversar sobre Geografia Histórica e a Revista Brasileira de Educação em Geografia. Agradecemos a Straforini pela oportunidade e deixamos o leitor com o resultado desse encontro virtual.

  12. When Professors Don't Return Essays.

    Science.gov (United States)

    Feldman, William; Dhaliwal, Gurpreet

    2015-01-01

    Students devote hundreds of hours to writing notes during medical school clerkships but receive very limited feedback on that work. Medical student notes are like college essays-both are persuasive compositions. But attending physicians rarely scrutinize student notes like college professors analyze essays. This is a missed opportunity to teach clinical reasoning. A survey at our institution showed that only 16% of students received written feedback and 31% received oral feedback on their notes from more than 3 attending physicians during the first 8 months of 3rd-year clerkships. Many studies have reported a paucity of feedback across multiple domains and a sense among students that clinical reasoning is not being adequately taught during clerkships. Meanwhile, college professors teach written composition and reasoning through interactive methods that help students to develop structured, well-reasoned arguments. A recent study showed that 85% of Oxford undergraduates favored these demanding and time-intensive tutorials. Attending physicians who adopt a tutorial-based approach toward their students' notes would have a forum to teach clinical reasoning and emphasize the importance of written composition in medical practice.

  13. FORMANDO PROFESSORES: UMA HEURÍSTICA REFLEXIVA

    Directory of Open Access Journals (Sweden)

    Tania Gastão Saliés

    2011-03-01

    Full Text Available O presente estudo reflete criticamente sobre a formação do professor de LE à luz da condição pós-método, com o intuito de contribuir para a ação de programas de formação.  Dentre outras questões, ilumina a importância de o professor em formação construir percepção sobre o contexto e de si próprio como agente da própria formação.  Para tal, primeiro trata de aspectos filosóficos presentes no contra-discurso da condição pós-método, em seguida destaca a conscientização sobre o papel do contexto no ensino-aprendizagem de línguas e finalmente  apresenta uma heurística reflexiva com potencial de guiar as ações dos cursos de formação.    

  14. Rotary condenser for SC2

    CERN Multimedia

    1975-01-01

    During 1975 the SC2 performance was improved among other things by redesigning some of the elements of the ROTCO (Annual Report 1975, p. 55). The photo shows an interior wiew of the housing of the rotary condenser and of the sixteen sets of shaped stator blades.

  15. Approaching Bose-Einstein Condensation

    Science.gov (United States)

    Ferrari, Loris

    2011-01-01

    Bose-Einstein condensation (BEC) is discussed at the level of an advanced course of statistical thermodynamics, clarifying some formal and physical aspects that are usually not covered by the standard pedagogical literature. The non-conventional approach adopted starts by showing that the continuum limit, in certain cases, cancels out the crucial…

  16. KAON CONDENSATION IN NEUTRON STARS.

    Energy Technology Data Exchange (ETDEWEB)

    RAMOS,A.; SCHAFFNER-BIELICH,J.; WAMBACH,J.

    2001-04-24

    We discuss the kaon-nucleon interaction and its consequences for the change of the properties of the kaon in the medium. The onset of kaon condensation in neutron stars under various scenarios as well its effects for neutron star properties are reviewed.

  17. Bose-Einstein Condensation Observed

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 1; Issue 2. Bose-Einstein Condensation Observed. Rajaram Nityananda. Research News Volume 1 Issue 2 February 1996 pp 111-114. Fulltext. Click here to view fulltext PDF. Permanent link: http://www.ias.ac.in/article/fulltext/reso/001/02/0111-0114 ...

  18. Modelling of silicon condenser microphones

    NARCIS (Netherlands)

    van der Donk, A.G.H.; van der Donk, A.G.H.; Scheeper, P.R.; Scheeper, P.R.; Olthuis, Wouter; Bergveld, Piet

    1994-01-01

    Several models concerning the sensitivity of capacitive pressure sensors have been presented in the past. Modelling of condenser microphones, which can be considered to be a special type of capacitive pressure sensor, usually requires a more complicated analysis of the sensitivity, because they have

  19. Topological states of condensed matter

    Science.gov (United States)

    Wang, Jing; Zhang, Shou-Cheng

    2017-11-01

    Topological states of quantum matter have been investigated intensively in recent years in materials science and condensed matter physics. The field developed explosively largely because of the precise theoretical predictions, well-controlled materials processing, and novel characterization techniques. In this Perspective, we review recent progress in topological insulators, the quantum anomalous Hall effect, chiral topological superconductors, helical topological superconductors and Weyl semimetals.

  20. Classical Dynamics of Excitations of Bose Condensates in Anisotropic Traps

    Science.gov (United States)

    Graham, Robert

    This lecture discusses some aspects of the dynamics of the collective and single-particle excitations at zero temperature of Bose-Einstein condensates of alkali-vapors in magnetic traps. We shall discuss those aspects which can be understood by taking the short-wavelength or 'eikonal' limit of the excitations. Trapped Bose-Einstein condensates can be excited experimentally either directly via periodic modulations of the trap potential or by scattering light off the condensate. My discussion here will closely follow some theoretical work published in [1-3] that has recently been done in collaboration with Andras Csordas and Peter Szepfalusy at the Research Institute for solid State Physics and Optics in Budapest, Hungary and with Martin Fliesser at the University of Essen, Germany.

  1. International Workshop on Current Problems in Condensed Matter

    CERN Document Server

    Current Problems in Condensed Matter

    1998-01-01

    This volume contains the papers presented at the International Workshop on the Cur­ rent Problems in Condensed Matter: Theory and Experiment, held at Cocoyoc, More­ los, Mexico, during January 5-9, 1997. The participants had come from Argentina, Austria, Chile, England, France, Germany, Italy, Japan, Mexico, Switzerland, and the USA. The presentations at the Workshop provided state-of-art reviews of many of the most important problems, currently under study, in condensed matter. Equally important to all the participants in the workshop was the fact that we had come to honor a friend, Karl Heinz Bennemann, on his sixty-fifth birthday. This Festschrift is just a small measure of recognition of the intellectualleadership of Professor Bennemann in the field and equally important, as a sincere tribute to his qualities as an exceptional friend, college and mentor. Those who have had the privilege to work closely with Karl have been deeply touched by Karl's inquisitive scientific mind as well as by bis k...

  2. An important achievement of Professor Ion Stroescu: the wind tunnel of the Polytechnic School of Bucharest

    Directory of Open Access Journals (Sweden)

    Nicolae-Serban TOMESCU

    2011-12-01

    Full Text Available This paper summarizes the contribution of Ion Stroescu to the experimental aerodynamics development in Romania through the design, in collaboration with Professor Elie Carafoli, of the subsonic wind tunnel of the Polytechnic School in Bucharest. Without any exaggeration, the paper also presents the general context in which this construction was built, when aeronautical higher education was being set up in Romania and young aviation industry made strides to world affirmation by its achievements.

  3. The order of condensation in capillary grooves.

    Science.gov (United States)

    Rascón, Carlos; Parry, Andrew O; Nürnberg, Robert; Pozzato, Alessandro; Tormen, Massimo; Bruschi, Lorenzo; Mistura, Giampaolo

    2013-05-15

    We consider capillary condensation in a deep groove of width L. The transition occurs at a pressure p(co)(L) described, for large widths, by the Kelvin equation p(sat) - p(co)(L) = 2σ cosθ/L, where θ is the contact angle at the side walls and σ is the surface tension. The order of the transition is determined by the contact angle of the capped end θcap; it is continuous if the liquid completely wets the cap, and first-order otherwise. When the transition is first-order, corner menisci at the bottom of the capillary lead to a pronounced metastability, determined by a complementary Kelvin equation Δp(L) = 2σ sinθcap/L. On approaching the wetting temperature of the capillary cap, the corner menisci merge and a single meniscus unbinds from the bottom of the groove. Finite-size scaling shifts, crossover behaviour and critical singularities are determined at mean-field level and beyond. Numerical and experimental results showing the continuous nature of condensation for θcap = 0 and the influence of corner menisci on adsorption isotherms are presented.

  4. Investigation of viscosity of whole hydrolyze sweetened condensed milk

    Directory of Open Access Journals (Sweden)

    O. Kalinina

    2015-05-01

    Full Text Available Introduction. Рaper is aimed at developing of low-lactose (hydrolyzed sweetened condensed milk products technology for lactose intolerant people and for the whole population. Materials and methods: Rheological characteristics were determined on a Reotest device by the 2 nd method of viscometry Results and discussion. Reasonability of ß-galactosidase use for milk lactose hydrolyze during the production of canned products with sugar was proved in the previous works. This technology gives possibility to increase the quality of condensed canned foods, to reduce sugar concentration till 50 %, to increase dietary properties. Due to the reducing of saccharose mass part till 22 and 31 % the products had a liquid consistency that’s why was a necessity to increase the viscosity properties of condensed products. One of method to increase the product viscosity is inoculation of stabilization systems. Reasonability of the usage of stabilization system Bivicioc 1L was proved. The researches of viscosity determination in whole hydrolyzed sweetened condensed milk were shown in the work. Relations of viscosity of whole hydrolyzed condensed milk to the deformation rate were presented. Conclusions Viscosity indices of experimental samples in the fresh produced products and during storage are determined and justified.

  5. Highly condensed aromatics and their connection to hydrogenation asphalts

    Energy Technology Data Exchange (ETDEWEB)

    Boente, L.

    1944-11-22

    An attempt is made to account for the structure of asphalts and resins which arose in residues upon hydrogenation of coal. The main assumption is that most of these asphalts consisted of highly condensed aromatics, which are considered as derivatives of the substance coronene, which could be described as having the structure consisting of six benzene rings arranged around a central seventh benzene ring. Part of the discussion is speculative, but evidence is given which had led to that speculation. The asphalts had been very hard to analyze exactly, partly because of their very low solubility in most solvents and their very high boiling points. Possible mechanisms for the formation of such highly condensed aromatics during the hydrogenation process are described along with experimental work aimed in part at hydrogenating these aromatics and in part at producing them by condensation reactions of aluminum chloride on coronene. Some of the products of the condensation reactions even resembled coke or soot, while others were red substances which fluoresced green in phenanthrene solution. It is hypothesized that coronene could be looked upon as the basic nucleus for a whole series of highly condensed aromatic molecules, in the same way that benzene is looked upon as the basic nucleus for a whole series of aromatic compounds.

  6. Heat transfer degradation during condensation of non-azeotropic mixtures

    Science.gov (United States)

    Azzolin, M.; Berto, A.; Bortolin, S.; Del, D., Col

    2017-11-01

    International organizations call for a reduction of the HFCs production and utilizations in the next years. Binary or ternary blends of hydroflourocarbons (HFCs) and hydrofluoroolefins (HFOs) are emerging as possible substitutes for high Global Warming Potential (GWP) fluids currently employed in some refrigeration and air-conditioning applications. In some cases, these mixtures are non-azeotropic and thus, during phase-change at constant pressure, they present a temperature glide that, for some blends, can be higher than 10 K. Such temperature variation during phase change could lead to a better matching between the refrigerant and the water temperature profiles in a condenser, thus reducing the exergy losses associated with the heat transfer process. Nevertheless, the additional mass transfer resistance which occurs during the phase change of zeotropic mixtures leads to a heat transfer degradation. Therefore, the design of a condenser working with a zeotropic mixture poses the problem of how to extend the correlations developed for pure fluids to the case of condensation of mixtures. Experimental data taken are very helpful in the assessment of design procedures. In the present paper, heat transfer coefficients have been measured during condensation of zeotropic mixtures of HFC and HFO fluids. Tests have been carried out in the test rig available at the Two Phase Heat Transfer Lab of University of Padova. During the condensation tests, the heat is subtracted from the mixture by using cold water and the heat transfer coefficient is obtained from the measurement of the heat flux on the water side, the direct measurements of the wall temperature and saturation temperature. Tests have been performed at 40°C mean saturation temperature. The present experimental database is used to assess predictive correlations for condensation of mixtures, providing valuable information on the applicability of available models.

  7. Professor Gender, Age, and “Hotness” in Influencing College Students’ Generation and Interpretation of Professor Ratings

    Directory of Open Access Journals (Sweden)

    Sara L. Sohr-Preston

    2016-09-01

    Full Text Available Undergraduate psychology students rated expectations of a bogus professor (randomly designated a man or woman and hot versus not hot based on an online rating and sample comments as found on RateMyProfessors.com (RMP. Five professor qualities were derived using principal components analysis (PCA: dedication, attractiveness, enhancement, fairness, and clarity. Participants rated current psychology professors on the same qualities. Current professors were divided based on gender (man or woman, age (under 35 or 35 and older, and attractiveness (at or below the median or above the median. Using multivariate analysis of covariance (MANCOVA, students expected hot professors to be more attractive but lower in clarity. They rated current professors as lowest in clarity when a man and 35 or older. Current professors were rated significantly lower in dedication, enhancement, fairness, and clarity when rated at or below the median on attractiveness. Results, with previous research, suggest numerous factors, largely out of professors’ control, influencing how students interpret and create professor ratings. Caution is therefore warranted in using online ratings to select courses or make hiring and promotion decisions.

  8. Professor Gender, Age, and “Hotness” in Influencing College Students’ Generation and Interpretation of Professor Ratings

    Directory of Open Access Journals (Sweden)

    Sara L. Sohr-Preston

    2016-09-01

    Full Text Available Undergraduate psychology students rated expectations of a bogus professor (randomly designated a man or woman and hot versus not hot based on an online rating and sample comments as found on RateMyProfessors.com (RMP. Five professor qualities were derived using principal components analysis (PCA: dedication, attractiveness, enhancement, fairness, and clarity. Participants rated current psychology professors on the same qualities. Current professors were divided based on gender (man or woman, age (under 35 or 35 and older, and attractiveness (at or below the median or above the median. Using multivariate analysis of covariance (MANCOVA, students expected hot professors to be more attractive but lower in clarity. They rated current professors as lowest in clarity when a man and 35 or older. Current professors were rated significantly lower in dedication, enhancement, fairness, and clarity when rated at or below the median on attractiveness. Results, with previous research, suggest numerous factors, largely out of professors’ control, influencing how students interpret and create professor ratings. Caution is therefore warranted in using online ratings to select courses or make hiring and promotion decisions. 

  9. Institutional Support for the Virtual Professor

    Directory of Open Access Journals (Sweden)

    Tom JONES

    2004-01-01

    Full Text Available Academics who hold positions at single-mode, distance education institutions are presently being hampered by an adherence to a long-standing set of protocols (specific office location, face-to-face meetings that were put in place when the conventional post-secondary was the norm. With the advent of a powerful merging of personal computers and the internet, a shift from those protocols to one of support for the virtual professor is in the offing, to the benefit of both the professoriate and the student. A key factor in this shift is the degree and quality of institutional support that will allow these changes to take place. This paper focuses on a number of the key factors that will have to be addressed if this new type of distance education academic is to function effectively.

  10. Continuous Droplet Removal upon Dropwise Condensation of Humid Air on a Hydrophobic Micropatterned Surface

    Science.gov (United States)

    2015-01-01

    Combination of two physical phenomena, capillary pressure gradient and wettability gradient, allows a simple two-step fabrication process that yields a reliable hydrophobic self-cleaning condenser surface. The surface is fabricated with specific microscopic topography and further treatment with a chemically inert low-surface-energy material. This process does not require growth of nanofeatures (nanotubes) or hydrophilic–hydrophobic patterning of the surface. Trapezoidal geometry of the microfeatures facilitates droplet transfer from the Wenzel to the Cassie state and reduces droplet critical diameter. The geometry of the micropatterns enhances local coalescence and directional movement for droplets with diameter much smaller than the radial length of the micropatterns. The hydrophobic self-cleaning micropatterned condenser surface prevents liquid film formation and promotes continuous dropwise condensation cycle. Upon dropwise condensation, droplets follow a designed wettability gradient created with micropatterns from the most hydrophobic to the least hydrophobic end of the surface. The surface has higher condensation efficiency, due to its directional self-cleaning property, than a plain hydrophobic surface. We explain the self-actuated droplet collection mechanism on the condenser surface and demonstrate experimentally the creation of an effective wettability gradient over a 6 mm radial distance. In spite of its fabrication simplicity, the fabricated surface demonstrates self-cleaning property, enhanced condensation performance, and reliability over time. Our work enables creation of a hydrophobic condenser surface with the directional self-cleaning property that can be used for collection of biological (chemical, environmental) aerosol samples or for condensation enhancement. PMID:25073014

  11. On nitrogen condensation in hypersonic nozzle flows: Numerical method and parametric study

    KAUST Repository

    Lin, Longyuan

    2013-12-17

    A numerical method for calculating two-dimensional planar and axisymmetric hypersonic nozzle flows with nitrogen condensation is developed. The classical nucleation theory with an empirical correction function and the modified Gyarmathy model are used to describe the nucleation rate and the droplet growth, respectively. The conservation of the liquid phase is described by a finite number of moments of the size distribution function. The moment equations are then combined with the Euler equations and are solved by the finite-volume method. The numerical method is first validated by comparing its prediction with experimental results from the literature. The effects of nitrogen condensation on hypersonic nozzle flows are then numerically examined. The parameters at the nozzle exit under the conditions of condensation and no-condensation are evaluated. For the condensation case, the static pressure, the static temperature, and the amount of condensed fluid at the nozzle exit decrease with the increase of the total temperature. Compared with the no-condensation case, both the static pressure and temperature at the nozzle exit increase, and the Mach number decreases due to the nitrogen condensation. It is also indicated that preheating the nitrogen gas is necessary to avoid the nitrogen condensation even for a hypersonic nozzle with a Mach number of 5 operating at room temperatures. © 2013 Springer-Verlag Berlin Heidelberg.

  12. Gaugino Condensation in the Early Universe

    OpenAIRE

    Matsuda, Tomohiro

    1996-01-01

    We examine the process of formation of the gaugino condensation within a Nambu-Jona-Lasinio type approach. We construct an effective Lagrangian description for the gaugino condensation which include a Weyl compensator superfield whose vacuum expectation value is related to the gaugino condensation.

  13. TEN YEARS OF "CONDENSED MATTER PHYSICS"

    OpenAIRE

    Editors

    2003-01-01

    This year the journal "Condensed Matter Physics" celebrates its tenth anniversary. It was founded in 1993 by the Institute for Condensed Matter Physics of the National Academy of Sciences of Ukraine for the purpose of publishing the regular and review papers in the field of statistical mechanics and condensed matter theory.

  14. Polymer induced condensation of dna supercoils

    NARCIS (Netherlands)

    Bessa Ramos Jr., J.E.; Ruggiero Neto, J.; Vries, de R.J.

    2008-01-01

    Macromolecular crowding is thought to be a significant factor driving DNA condensation in prokaryotic cells. Whereas DNA in prokaryotes is supercoiled, studies on crowding-induced DNA condensation have so far focused on linear DNA. Here we compare DNA condensation by poly(ethylene oxide) for

  15. Majorana fermions in condensed matter: An outlook

    Science.gov (United States)

    Ma, Ning

    2017-05-01

    The Majorana fermions (MFs) were firstly envisioned by Majorana in 1937 as fundamental constituents of nature, whereas experimentally thus far unobserved in the realm of fundamental particles. More recent studies have revealed that the MFs could occur in condensed matter physics as emergent quasiparticle excitations in effectively spinless p-wave topological superconductors (TS). They are shown to behave as effectively fractionalized anyons following non-Abelian braiding statistics rather than the usual Fermi or Bose exchange statistics. This extraordinary property would directly lead to a perpetually coherent and fault tolerant topological quantum computation in 2D systems. Currently the experiments searching for MFs on much more special systems are ongoing and the investigations of MFs' behavior in TS-coupled systems are also been actively pursued, with the goal of deeply understanding the fundamental physics of fractional statistics in nature, and further paving more feasible ways toward a working universal topological quantum computer.

  16. Yield stress materials in soft condensed matter

    Science.gov (United States)

    Bonn, Daniel; Denn, Morton M.; Berthier, Ludovic; Divoux, Thibaut; Manneville, Sébastien

    2017-07-01

    A comprehensive review is presented of the physical behavior of yield stress materials in soft condensed matter, which encompasses a broad range of materials from colloidal assemblies and gels to emulsions and non-Brownian suspensions. All these disordered materials display a nonlinear flow behavior in response to external mechanical forces due to the existence of a finite force threshold for flow to occur: the yield stress. Both the physical origin and rheological consequences associated with this nonlinear behavior are discussed and an overview is given of experimental techniques available to measure the yield stress. Recent progress is discussed concerning a microscopic theoretical description of the flow dynamics of yield stress materials, emphasizing, in particular, the role played by relaxation time scales, the interplay between shear flow and aging behavior, the existence of inhomogeneous shear flows and shear bands, wall slip, and nonlocal effects in confined geometries.

  17. Students' Needs Analysis in an EFL Program for University Professors

    Science.gov (United States)

    Bedoya, Paula Andrea; Valencia, Luz María; Montoya, Juan Carlos

    2016-01-01

    This study sets out to investigate professors' needs from an English as a foreign language program in a public university regarding demands, interests, and lacks based on the methodology of needs analysis. Data collected through a survey, focus groups, and individual interviews showed that professors need to meet the institutional language policy…

  18. Rate My Professor: Online Evaluations of Psychology Instructors

    Science.gov (United States)

    Silva, Kathleen M.; Silva, Francisco J.; Quinn, Megan A.; Draper, Jill N.; Cover, Kimberly R.; Munoff, Alison A.

    2008-01-01

    We analyzed students' ratings and comments of their psychology instructors that were posted on RateMyProfessors.com and RateMyProfessors.ca to determine which features of a course and an instructor evoked the most positive and negative reactions. A content analysis of students' comments showed that instructors' characteristics(e.g., enthusiastic,…

  19. More Colleges Offer Part-Time Options for Professors

    Science.gov (United States)

    Wilson, Robin

    2008-01-01

    The University of California campuses are among a small but growing number of research universities adopting new policies--or reinvigorating old ones--that allow tenure-track and tenured professors to work part time. Typically, professors interested in scaling back their work want more time to care for young children, a sick relative, or an aging…

  20. Child Rearing as a Career Impediment to Women Assistant Professors.

    Science.gov (United States)

    Finkel, Susan Kolker; Olswang, Steven G.

    1996-01-01

    Over 40% of women assistant professors in a recent survey (n=124) identified publishing, teaching, committees, and "time required by children" as serious impediments to achieving tenure, many more than reported sexual harassment and sexism as serious obstacles. Policy changes that will accommodate women professors' time commitments to…

  1. Do Professors Have Customer-Based Brand Equity?

    Science.gov (United States)

    Jillapalli, Ravi K.; Jillapalli, Regina

    2014-01-01

    This research endeavors to understand whether certain professors have customer-based brand equity (CBBE) in the minds of students. Consequently, the purpose of this study is to conceptualize, develop, and empirically test a model of customer-based professor brand equity. Survey data gathered from 465 undergraduate business students were used to…

  2. Academic Labor Markets and Assistant Professors' Employment Outcomes

    Science.gov (United States)

    Hargens, Lowell L.

    2012-01-01

    Using data for 638 assistant professors who joined graduate sociology departments between 1975 and 1992, I examine the claim that when the labor market for new doctorates is weak, assistant professors experience less favorable employment outcomes than when that labor market is strong. Surprisingly, I find that those hired during the weak…

  3. Effects of Social Support on Professors' Work Stress

    Science.gov (United States)

    Moeller, Christin; Chung-Yan, Greg A.

    2013-01-01

    Purpose: The purpose of this paper is to examine how various types of workplace social support from different support sources interact with occupational stressors to predict the psychological well-being of university professors. Design/method/approach: A total of 99 full-time professors participated via an online or paper questionnaire. Findings:…

  4. Mentoring by the Community College Professor: One Role among Many

    Science.gov (United States)

    Galbraith, Michael; James, Waynne

    2004-01-01

    The process of mentorship in relationship to the community college professor and the potential to improve and enhance the teaching and learning process is explored in this article. This article suggests that not all community college professors are psychological or intellectually disposed to being or becoming a good mentor. It is put forth that…

  5. 26 CFR 521.114 - Visiting professors or teachers.

    Science.gov (United States)

    2010-04-01

    ... 26 Internal Revenue 19 2010-04-01 2010-04-01 false Visiting professors or teachers. 521.114... of Denmark and of Danish Corporations § 521.114 Visiting professors or teachers. Under Article XIV of... States for the purpose of teaching, lecturing, or instructing at any university, college, school, or...

  6. Mental Health Assessment in Professors' Training in Two Chilean Universities

    Science.gov (United States)

    Ossa, Carlos J.; Quintana, Ingrid M.; Rodriguez, Felipe F.

    2015-01-01

    This study analyzed the evaluation of professors of pedagogy and directors programs, about the importance of mental health in vocational training, and factors that might influence this valuation. The methodology includes participation of 17 academicians (professors and belonging to the managerial staff) of two universities in southern Chile. A…

  7. Differentiated Instruction: Are University Reading Professors Implementing It?

    Science.gov (United States)

    Williams-Black, Thea Hayes; Bailey, Jennifer P.; Lawson, Pamela D. Coleman

    2010-01-01

    This qualitative study surveyed university professors of literacy education to explore "how" and "if" they modeled differentiated instruction in their own college classrooms. A survey in questionnaire format on "how" and "if" University Reading Professors differentiate instruction was sent to a purposeful…

  8. University Pedagogy for Assistant Professors at Aalborg University (Part 2)

    DEFF Research Database (Denmark)

    Kolmos, Anette; Krogh, Lone

    2003-01-01

    In issue 1-2003, Anette Kolmos and Lone Krogh reported on the two-semester study course " University Pedagogy for Assistant Professors at Aalborg University (DK)". Now, in part 2, they are adressing guidelines for supervison and advising of assistant professors in the university teacher education...

  9. Student and Professor Gender Effects in Introductory Business Statistics

    Science.gov (United States)

    Haley, M. Ryan; Johnson, Marianne F.; Kuennen, Eric W.

    2007-01-01

    Studies have yielded highly mixed results as to differences in male and female student performance in statistics courses; the role that professors play in these differences is even less clear. In this paper, we consider the impact of professor and student gender on student performance in an introductory business statistics course taught by…

  10. Quark condensation in quantum chromodynamics

    Energy Technology Data Exchange (ETDEWEB)

    Finger, J.; Horn, D.; Mandula, J.E.

    1979-12-15

    Working within a limited Fock-space approximation (LFSA), we argue that if the running coupling constant of quantum chromodynamics (QCD) exceeds a critical value of order 1 the vacuum becomes a condensate of quark-antiquark pairs. To evaluate the critical coupling constant we use a Mellin-transform technique which is first illustrated with a Schroedinger equation problem. We then apply it to scalar and spinor QED, as well as to QCD, using the LFSA.

  11. In commemoration of professor V.P. Karpov

    Directory of Open Access Journals (Sweden)

    Semyonova L.S.

    2013-10-01

    Full Text Available This article is about professor Karpov V.P., a prominent scientist, first rector of Yekaterinoslav Medical Academy. Biography of a great investigator, his main achievements in the area of histology, biology, theory and history of medicine was studied. Professor Karpov V.P. always combined his great scientific, organizational and research work with social activity. Monographs of professor Karpov V.P. and conferences organized by him were of great importance in the solution of such new problems as theary of microscope and cell amitosis. Professor Karpov is a founder of a large school of histology. Thanks to his active participation and personal guidance, in 1917 department of histology was founded in Yekaterinoslav Medical Institute. The author of the article has analyzed Hippocrates` works translated into Russian by professor Karpov V.P. and pointed out their significance for modern medical science and practice.

  12. Professor I I Glass A Tribute and Memorial

    CERN Document Server

    Igra, Ozer

    2013-01-01

    The book provides personal memories along with description of scientific works written by ex-graduate students and research associates of the late Professor Glass. The described research work covers a wide range of shock wave phenomena, resulting from seeds planted by Professor Glass. Professor Glass was born in Poland in 1918. He immigrated together with his parents to Canada at the age of 12 and received all his professional education at the University of Toronto, Canada. He became a world recognized expert in shock wave phenomena, and during his 45 years of active research he supervised more than 125 master and doctoral students, post-doctoral fellows and visiting research associates. In this book seven of his past students/research-associates describe their personal memories of Professor Glass and present some of their investigations in shock wave phenomena which sprung from their past work with Professor Glass. Specifically, these investigations include underwater shock waves, shock/bubble interaction, m...

  13. Creation of 39K Bose-Einstein condensates with tunable interaction

    DEFF Research Database (Denmark)

    Winter, Nils

    2013-01-01

    Bose-Einstein condensates and thus accumulate ultracold atoms in a single quantum state enables the construction of model systems which can be precisely controlled. That allows a deeper understanding of complicated quantum systems. Ultracold atoms in optical lattices are an excellent example, since...... ultracold atoms. Secondly an experimental apparatus for the creation and investigation of ultracold potassium-rubidium mixtures with tunable interactions was constructed and first 39K and 41K Bose-Einstein condensates were created. This experimental apparatus features a dual-species magneto-optical trap......-species Bose-Einstein condensates consisting of 6×105 87Rb atoms, 2×105 39K atoms and 1×104 41K atoms. The creation of dual-species condensates will be the next experimental milestone. This will allow for the investigation of the interaction within ultracold potassium-rubidium mixtures leading to the creation...

  14. OBITUARY: Professor Jan Evetts in memoriam

    Science.gov (United States)

    Dew-Hughes, David; Campbell, Archie; Glowacki, Bartek

    2005-11-01

    It is with great sadness that we report the death of Jan Evetts, who lost his second battle with cancer on 18 August 2005. In 1988 he was appointed Founding Editor of this journal where his leadership created the foundation upon which its success rests today. He made an outstanding series of contributions to the science of superconductivity and to the understanding of superconducting materials, and was an indefatigable champion of the development of applications of superconductivity. The loss to the scientific community is incalculable, as is attested by the many communications received from colleagues throughout the world. Professor Jan Edgar Evetts (1939-2005) Professor Jan Edgar Evetts (1939-2005) Jan was born on 31 March 1939, and attended the Dragon School in Oxford, and later Haileybury. He was awarded an exhibition to read Natural Sciences at Pembroke College, Cambridge in 1958 and took his BA degree in 1961. He then undertook a Certificate of Postgraduate Study in Physics under the supervision of Professor Neville Mott. He was the first student to undertake this newly-instituted course; the title of his thesis was `The Resistance of Transition Metals'. In 1962 he joined David Dew-Hughes' embryonic superconducting materials research group, along with Archie Campbell and Anant Narlikar. In fact it was Jan's enthusiasm for the proposed course of research that helped convince David that he should follow Professor Alan Cottrell's suggestion to apply metallurgical methodology to the study of the factors that controlled critical current density in the type II superconductors that were then under development for applications in magnets. Competing theories for the critical current density at that time were fine filaments or `Mendelssohn Sponge' versus the pinning of Abrikosov quantized vortices. The results of the group's work, to which Jan made a major contribution, came down heavily in favour of the latter theory. Jan's outstanding characteristic was his

  15. Universal Themes of Bose-Einstein Condensation

    Science.gov (United States)

    Proukakis, Nick P.; Snoke, David W.; Littlewood, Peter B.

    2017-04-01

    Foreword; List of contributors; Preface; Part I. Introduction: 1. Universality and Bose-Einstein condensation: perspectives on recent work D. W. Snoke, N. P. Proukakis, T. Giamarchi and P. B. Littlewood; 2. A history of Bose-Einstein condensation of atomic hydrogen T. Greytak and D. Kleppner; 3. Twenty years of atomic quantum gases: 1995-2015 W. Ketterle; 4. Introduction to polariton condensation P. B. Littlewood and A. Edelman; Part II. General Topics: Editorial notes; 5. The question of spontaneous symmetry breaking in condensates D. W. Snoke and A. J. Daley; 6. Effects of interactions on Bose-Einstein condensation R. P. Smith; 7. Formation of Bose-Einstein condensates M. J. Davis, T. M. Wright, T. Gasenzer, S. A. Gardiner and N. P. Proukakis; 8. Quenches, relaxation and pre-thermalization in an isolated quantum system T. Langen and J. Schmiedmayer; 9. Ultracold gases with intrinsic scale invariance C. Chin; 10. Berezinskii-Kosterlitz-Thouless phase of a driven-dissipative condensate N. Y. Kim, W. H. Nitsche and Y. Yamamoto; 11. Superfluidity and phase correlations of driven dissipative condensates J. Keeling, L. M. Sieberer, E. Altman, L. Chen, S. Diehl and J. Toner; 12. BEC to BCS crossover from superconductors to polaritons A. Edelman and P. B. Littlewood; Part III. Condensates in Atomic Physics: Editorial notes; 13. Probing and controlling strongly correlated quantum many-body systems using ultracold quantum gases I. Bloch; 14. Preparing and probing chern bands with cold atoms N. Goldman, N. R. Cooper and J. Dalibard; 15. Bose-Einstein condensates in artificial gauge fields L. J. LeBlanc and I. B. Spielman; 16. Second sound in ultracold atomic gases L. Pitaevskii and S. Stringari; 17. Quantum turbulence in atomic Bose-Einstein condensates N. G. Parker, A. J. Allen, C. F. Barenghi and N. P. Proukakis; 18. Spinor-dipolar aspects of Bose-Einstein condensation M. Ueda; Part IV. Condensates in Condensed Matter Physics: Editorial notes; 19. Bose

  16. The influence of surface-active agents in gas mixture on the intensity of jet condensation

    Science.gov (United States)

    Yezhov, YV; Okhotin, VS

    2017-11-01

    The report presents: the methodology of calculation of contact condensation of steam from the steam-gas mixture into the stream of water, taking into account: the mass flow of steam through the boundary phase, particularly the change in turbulent transport properties near the interface and their connection to the interface perturbations due to the surface tension of the mixture; the method of calculation of the surface tension at the interface water - a mixture of fluorocarbon vapor and water, based on the previously established analytical methods we calculate the surface tension for simple one - component liquid-vapor systems. The obtained analytical relation to calculate the surface tension of the mixture is a function of temperature and volume concentration of the fluorocarbon gas in the mixture and is true for all sizes of gas molecules. On the newly created experimental stand is made verification of experimental studies to determine the surface tension of pure substances: water, steam, C3F8 pair C3F8, produced the first experimental data on surface tension at the water - a mixture of water vapor and fluorocarbon C3F8. The obtained experimental data allow us to refine the values of the two constants used in the calculated model of the surface tension of the mixture. Experimental study of jet condensation was carried out with the flow in the zone of condensation of different gases. The condensation process was monitored by measurement of consumption of water flowing from the nozzle, and the formed condensate. When submitting C3F8, there was a noticeable, intensification condensation process compared with the condensation of pure water vapor. The calculation results are in satisfactory agreement with the experimental data on surface tension of the mixture and steam condensation from steam-gas mixture. Analysis of calculation results shows that the presence of surfactants in the condensation zone affects the partial vapor pressure on the interfacial surface, and

  17. The Effect of Condensate Inundation on Condensation Heat Transfer in Tube Bundles of Marine Condensers.

    Science.gov (United States)

    1980-12-01

    provides additional protection from contamination. After the strainer, the steam proceeds through a 31.75 mm. diameter line which provides for two...the system was tested for air-tightness and found to be secure. In addition , it was believed that the velocity of steam passing through the test...REFERENCES 1. Standards for Steam Surface Condensers, 6th ed., Heat Exchange Institue, 1970. 2. Standards of Tubular Exchanger Manifacturers Association

  18. Impacto vocal de professores Teachers' vocal impact

    Directory of Open Access Journals (Sweden)

    Adriana Ricarte

    2011-08-01

    Full Text Available OBJETIVO: analisar o impacto vocal nas atividades diárias em professores do ensino médio. Correlacionar os achado da auto-percepção do problema vocal com os aspectos: efeitos no trabalho, na comunicação diária, na comunicação social e na sua emoção. MÉTODOS: a amostra foi constituída por 107 professores, sendo 86 com queixa e 21 sem queixa, selecionados em escolas da rede particular de ensino de Maceió-AL. Cada professor respondeu individualmente o protocolo Perfil Participação em Atividades Vocais na presença da pesquisadora, assinalando suas respostas em uma escala visual que varia de 0 a 10. O protocolo é composto por 28 questões com a presença integrada em cinco aspectos englobados para avaliar a qualidade de vida e o resultado de tratamentos vocais. O protocolo oferece, ainda, dois escores adicionais: pontuação de limitação nas atividades (PLA e de restrição de participação (PRP. RESULTADOS: na comparação dos grupos com e sem queixa vocal foram verificados que todos os resultados foram estatisticamente significantes (pPURPOSE: to analyze the vocal impact in the daily activities on high-school teachers. Correlate the finding of the auto-perception on the vocal problem with the following aspects: effects in the work, daily communication, social communication and, its emotion METHODS: the sample consisted of 107 teachers, 86 with and 21 with no complaint, selected from private teaching schools in Maceió-AL. Each teacher answered individually the Protocol for Voice Activity Participation Profile in the presence of the researcher, noting their responses on a visual scale ranging from 0 to 10. The protocol is composed of 28 questions with the presence integrated in five aspects to evaluate the quality of life and the result of vocal treatments. The protocol offers, still, two additional scores: punctuation of limitation in the activities (PLA and restriction of participation (PRP. RESULTS: comparing the groups with

  19. A numerical study of the direct contact condensation on a horizontal surface

    Science.gov (United States)

    Hasan, M. M.; Lin, C. S.

    1991-01-01

    The results of a numerical study of the direct contact condensation on a slowly moving horizontal liquid surface are presented. The geometrical configuration and the input conditions used to obtain numerical solutions are representative to those of experiments of Celata et al. The effects of Prandtl number (Pr), inflow Reynolds number, and Richardson number on the condensation rate are investigated. Numerical predictions of condensation rate for laminar flow are in good agreement with experimental data. The effect of buoyancy on the condensation rate is characterized by Richardson number. A correlation based on the numerical solutions is developed to predict the average condensation Nusselt number in terms of Richardson number, Peclet number, and inflow Reynolds number.

  20. A bubble column evaporator with basic flat-plate condenser for brackish and seawater desalination.

    Science.gov (United States)

    Schmack, Mario; Ho, Goen; Anda, Martin

    2016-01-01

    This paper describes the development and experimental evaluation of a novel bubble column-based humidification-dehumidification system, for small-scale desalination of saline groundwater or seawater in remote regions. A bubble evaporator prototype was built and matched with a simple flat-plate type condenser for concept assessment. Consistent bubble evaporation rates of between 80 and 88 ml per hour were demonstrated. Particular focus was on the performance of the simple condenser prototype, manufactured from rectangular polyvinylchlorid plastic pipe and copper sheet, a material with a high thermal conductivity that quickly allows for conduction of the heat energy. Under laboratory conditions, a long narrow condenser model of 1500 mm length and 100 mm width achieved condensate recovery rates of around 73%, without the need for external cooling. The condenser prototype was assessed under a range of different physical conditions, that is, external water cooling, partial insulation and aspects of air circulation, via implementing an internal honeycomb screen structure. Estimated by extrapolation, an up-scaled bubble desalination system with a 1 m2 condenser may produce around 19 l of distilled water per day. Sodium chloride salt removal was found to be highly effective with condensate salt concentrations between 70 and 135 µS. Based on findings and with the intent to reduce material cost of the system, a shorter condenser length of 750 mm for the non-cooled (passive) condenser and of 500 mm for the water-cooled condenser was considered to be equally efficient as the experimentally evaluated prototype of 1500 mm length.

  1. In Memory of Professor Mohammad Hossein Salehi 1941-2014

    Directory of Open Access Journals (Sweden)

    Reza Bagheri

    2014-05-01

    Full Text Available Unfortunately, last winter, we lost one of the leaders of Radiotherpy-Oncology in Iran, Professor Mohammad Hossein Salehi. He was an excellent teacher, a supportive friend and an experienced physician.Professor Salehi was born on April 21, 1941 in Shirvan. After graduating from high school, he continued his education in Mashhad Medical School. In 1968 he completed Medical School and began the Residency Program of Radiology in Mashhad Medical School. Soon after, due to the lack of Radiotherapists in Mashhad and his eager to set up a Radiotherapy services in Mashhad, Dr. Salehi moved to England. He passed the Residency of Radiotherapy from 1972 to 1975 in the Royal Marsden Hospital, London and earned his Diploma in Medical Radiotherapy (D.M.R.T from the England Royal College and finished his fellowship ( F.R.C.R. After moving back to Iran in the same year and acquiring the Iranian National Board of Radiology, he started to work as Assistant Professor of Radiotherapy in Ghaem Hospital, Mashhad University of Medical Sciences, Iran. He arranged and established the first Radiotherapy Department in Mashhad in 1976. He was the Head of Radiotherapy-Oncology Department from 1976 to 2006.He was appointed as Associate Professor and after Professor of Radiotherapy-Oncology in 1985 and 1993, respectively. Professor Salehi was an active member of the Iranian National Board of Radiotherapy for 30 years. He was awarded as” The Best Professor “for 3 times.Beside his valuable clinical and educational activities, he was interested in medical research. He has published more than 20 articles and supervised about 25 theses. After 40 years continuous activity, Professor Salehi was retired in 2010. Unfortunately Professor Salehi passed away on January 23, 2014 after a four-year battle with metastatic colon cancer. His strength, wisdom, guidance and kindness will be missed by all who knew him.

  2. Interview with Professor Karl-Heinz Mehlan.

    Science.gov (United States)

    Neumann, H G

    1991-09-01

    Professor Karl-Heinz Mehlan, one of the founding fathers of German family planning in the post WWII area, celebrated his 75th birthday of July 18, 1991. The celebration took place in Rostock and Dr. Mehlan was in the best of health. As part of the occasion, Dr. Hans-Georg Neumann conducted an interview with Dr. Mehlan about the beginnings of family planning in what was then the Soviet occupied zone of Germany as well as its further development up to the present day. In the course of the interview Dr. Mehlan discussed the history of abortion in East Germany during the period of recovery immediately after WWII. He related his experiences working as a general practitioner in Calau and the committees he served on that were related to the study and delivery of abortion. During this time there were 80,000 recorded cases. After this he went to Berlin to the Institut fur Sozialmedizin der Chartie to write about the Calau experience. This was the 1st time that the abortion problem was discussed in German in a scientific context. He studied mortality, morbidity, and after effects.

  3. Editorial: A dedication to Professor Jan Evetts

    Science.gov (United States)

    Weber, Harald; Dew-Hughes, David; Campbell, Archie; Barber, Zoe; Somekh, Rob; Glowacki, Bartek

    2006-03-01

    A few days before the beginning of the 7th European Conference on Applied Superconductivity we learned that Professor Jan Evetts, a pioneer of superconductor research, a brilliant scientist, a wonderful person and a great personal friend, had passed away. We therefore decided to dedicate the 7th European Conference on Applied Superconductivity to the memory of Jan Evetts. The following citation is based on material provided by his former supervisor (D Dew-Hughes) and his closest co-workers in Cambridge. Professor Jan Edgar Evetts (1939-2005) Professor Jan Edgar Evetts (1939-2005) Jan Evetts passed away after losing his second battle with cancer on 24th August 2005. He made an outstanding series of contributions to the science of superconductivity and to the understanding of superconducting materials and was an indefatigable champion of the development of applications of superconductivity. The loss to the superconductivity community is incalculable, as attested by the many communications received from colleagues throughout the world. Jan was born on 31 March 1939, and attended the Dragon School in Oxford, and later Haileybury. He was awarded an exhibition to read Natural Sciences at Pembroke College, Cambridge. He entered the college in 1958 and took his BA degree in 1961. He then undertook a Certificate of Postgraduate Study in Physics under the supervision of Professor Neville Mott. He was the first student to undertake this newly-instituted course; the title of his thesis was `The Resistance of Transition Metals'. In 1962 he joined David Dew-Hughes' superconducting materials research group, along with Archie Campbell and Anant Narlikar. In fact it was Jan's enthusiasm for the proposed course of research that helped convince David that he should follow Professor Alan Cottrell's suggestion to apply metallurgical methodology to the study of the factors that controlled critical current density in the type II superconductors that were then under development for

  4. Condensation and Wetting Dynamics on Micro/Nano-Structured Surfaces

    Science.gov (United States)

    Olceroglu, Emre

    gases (NCGs), a novel characterization technique has been developed based on image tracking of droplet growth rates. The full-field dynamic characterization of superhydrophobic surfaces during condensation has been achieved using high-speed microscopy coupled with image-processing algorithms. This method is able to resolve heat fluxes as low as 20 W/m 2 and heat transfer coefficients of up to 1000 kW/m2, across an array of 1000's of microscale droplets simultaneously. Nanostructured surfaces with mixed wettability have been used to demonstrate delayed flooding during superhydrophobic condensation. These surfaces have been optimized and characterized using optical and electron microscopy, leading to the observation of self-organizing microscale droplets. The self-organization of small droplets effectively delays the onset of surface flooding, allowing the superhydrophobic surfaces to operate at higher supersaturations. Additionally, hierarchical surfaces have been fabricated and characterized showing enhanced droplet growth rates as compared to existing models. This enhancement has been shown to be derived from the presence of small feeder droplets nucleating within the microscale unit cells of the hierarchical surfaces. Based on the experimental observations, a mechanistic model for growth rates has been developed for superhydrophobic hierarchical surfaces. While superhydrophobic surfaces exhibit high heat transfer rates they are inherently unstable due to the necessity to maintain a non-wetted state in a condensing environment. As an alternative condensation surface, a novel design is introduced here using ambiphilic structures to promote the formation of a thin continuous liquid film across the surface which can still provide the benefits of superhydrophobic condensation. Preliminary results show that the ambiphilic structures restrain the film thickness, thus maintaining a low thermal resistance while simultaneously maximizing the liquid-vapor interface available for

  5. Quantum tunnelling in condensed media

    CERN Document Server

    Kagan, Yu

    1992-01-01

    The essays in this book deal with of the problem of quantum tunnelling and related behavior of a microscopic or macroscopic system, which interacts strongly with an ""environment"" - this being some form of condensed matter. The ""system"" in question need not be physically distinct from its environment, but could, for example, be one particular degree of freedom on which attention is focussed, as in the case of the Josephson junction studied in several of the papers. This general problem has been studied in many hundreds, if not thousands, of articles in the literature, in contexts as diverse

  6. Professor M.K. Vainu Bappu (1927-82)

    Science.gov (United States)

    West, R. M.

    1982-12-01

    It was with great sadness that we received the news of the death, on 19 August 1982, of Professor M.K.V. Bappu, President of the International Astronomical Union and Director of the Indian Institute of Astrophysics, Bangalore, India. Professor Bappu was spending a few months with ESO in Munich, doing research within solar and stellar spectroscopy and at the same time preparing for the XVIIIth IAU General Assembly. A heart ailment necessitated a major surgical intervention, which was apparently successful. Howeyer, post-operative complications set in, and after a heroic struggle, assisted by the foremost medical expertise, Professor Bappu expired in the early evening of 19 August.

  7. Professor perceptions of college students with attention deficit hyperactivity disorder.

    Science.gov (United States)

    Vance, Teresa Ann; Weyandt, Lisa

    2008-01-01

    From April to June 2005, the authors investigated professor perceptions of college students with attention deficit hyperactivity disorder (ADHD). 253 participants completed the ADHD Beliefs Survey-Revised, a 40-question survey measuring professor perceptions of ADHD. Analysis of variance measured false and reasonable beliefs related to ADHD. Results indicated that professors with differing levels of education, years of teaching experience, colleges in the university or community college, previous experiences with a student with ADHD, and ADHD training did not differ significantly in perceptions regarding general ADHD knowledge or college students with ADHD.

  8. The wavefunction of the collapsing Bose–Einstein condensate

    Science.gov (United States)

    Theodorakis, Stavros; Hadjigeorgiou, Andreas

    2017-12-01

    Bose–Einstein condensates with tunable interatomic interactions have been studied intensely in recent experiments. The investigation of the collapse of a condensate following a sudden change in the nature of the interaction from repulsive to attractive has led to the observation of a remnant condensate that did not undergo further collapse. We suggest that this high-density remnant is in fact the absolute minimum of the energy, if the attractive atomic interactions are nonlocal, and is therefore inherently stable. We show that a variational trial function consisting of a superposition of two distinct gaussians is an accurate representation of the wavefunction of the ground state of the conventional local Gross–Pitaevskii field equation for an attractive condensate and gives correctly the points of emergence of instability. We then use such a superposition of two gaussians as a variational trial function in order to calculate the minima of the energy when it includes a nonlocal interaction term. We use experimental data in order to study the long range of the nonlocal interaction, showing that they agree very well with a dimensionally derived expression for this range.

  9. FOREWORD: 18th International School on Condensed Matter Physics

    Science.gov (United States)

    Dimova-Malinovska, Doriana; Genova, Julia; Nesheva, Diana; Petrov, Alexander G.; Primatarowa, Marina T.

    2014-12-01

    We are delighted to present the Proceedings of the 18th International School on Condensed Matter Physics: Challenges of Nanoscale Science: Theory, Materials, Applications, organized by the Institute of Solid State Physics of the Bulgarian Academy of Sciences and chaired by Professor Alexander G Petrov. On this occasion the School was held in memory of Professor Nikolay Kirov (1943-2013), former Director of the Institute and Chairman between 1991 and 1998. The 18ISCMP was one of several events dedicated to the 145th anniversary of the Bulgarian Academy of Sciences in 2014, and was held in the welcoming Black Sea resort of St. Constantine and Helena near Varna, at the Hotel and Congress Centre Frederic Joliot-Curie. Participants from 16 countries delivered 32 invited lectures, and 71 contributed posters were presented over three lively and well-attended evening sessions. Manuscripts submitted to the Proceedings were refereed in accordance with the guidelines of the Journal of Physics: Conference Series, and we believe the papers published herein testify to the high technical quality and diversity of contributions. A satellite meeting, Transition Metal Oxide Thin Films - Functional Layers in Smart Windows and Water Splitting Devices: Technology and Optoelectronic Properties was held in parallel with the School (http://www.inera.org, 3-6 Sept 2014). This activity, which took place under the FP7-funded project INERA, offered opportunities for crossdisciplinary discussions and exchange of ideas between both sets of participants. As always, a major factor in the success of the 18ISCMP was the social programme, headed by the organized events (Welcome and Farewell Parties) and enhanced in no small measure by a variety of pleasant local restaurants, bars and beaches. We are most grateful to staff of the Journal of Physics: Conference Series for their continued support for the School, this being the third occasion on which the Proceedings have been published under its

  10. DNA condensation in one dimension.

    Science.gov (United States)

    Pardatscher, Günther; Bracha, Dan; Daube, Shirley S; Vonshak, Ohad; Simmel, Friedrich C; Bar-Ziv, Roy H

    2016-12-01

    DNA can be programmed to assemble into a variety of shapes and patterns on the nanoscale and can act as a template for hybrid nanostructures such as conducting wires, protein arrays and field-effect transistors. Current DNA nanostructures are typically in the sub-micrometre range, limited by the sequence space and length of the assembled strands. Here we show that on a patterned biochip, DNA chains collapse into one-dimensional (1D) fibres that are 20 nm wide and around 70 µm long, each comprising approximately 35 co-aligned chains at its cross-section. Electron beam writing on a photocleavable monolayer was used to immobilize and pattern the DNA molecules, which condense into 1D bundles in the presence of spermidine. DNA condensation can propagate and split at junctions, cross gaps and create domain walls between counterpropagating fronts. This system is inherently adept at solving probabilistic problems and was used to find the possible paths through a maze and to evaluate stochastic switching circuits. This technique could be used to propagate biological or ionic signals in combination with sequence-specific DNA nanotechnology or for gene expression in cell-free DNA compartments.

  11. Condensation induced water hammer safety

    Energy Technology Data Exchange (ETDEWEB)

    Gintner, M.A.

    1997-03-10

    Condensation induced water hammer events in piping systems can cause catastrophic steam system failures which can result in equipment damage, personal injury, and even death. As an industry, we have learned to become accustomed to the ''banging'' that we often hear in our steam piping systems, and complacent in our actions to prevent it. It is unfortunate that lives are lost needlessly, as this type of water hammer event is preventable if one only applies some basic principles when operating and maintaining their steam systems. At the U. S. Department of Energy's Hanford Site where I work, there was one such accident that occurred in 1993 which took the life of a former co-worker and friend of mine. Hanford was established as part of the Manhattan Project during World War II. it is a 560 square mile complex located along the banks of the Columbia River in Southeastern Washington State. For almost 45 years, hanford's mission was to produce weapons grade plutonium for our nations defense programs. Today, Hanford no longer produces plutonium, but is focused on site clean-up and economic diversification. Hanford still uses steam for heating and processing activities, utilizing over 20 miles of piping distribution systems similar to those found in industry. Although these aging systems are still sound, they cannot stand up to the extreme pressure pulses developed by a condensation induced water hammer.

  12. Approaching Bose-Einstein condensation

    Energy Technology Data Exchange (ETDEWEB)

    Ferrari, Loris, E-mail: loris.ferrari@unibo.it [Department of Physics of the University, Viale B. Pichat, 6/2, 40127, Bologna (Italy)

    2011-11-15

    Bose-Einstein condensation (BEC) is discussed at the level of an advanced course of statistical thermodynamics, clarifying some formal and physical aspects that are usually not covered by the standard pedagogical literature. The non-conventional approach adopted starts by showing that the continuum limit, in certain cases, cancels out the crucial role of the bosonic ground level. If so, a correct treatment of the problem, including the ground level population N{sub 0} by construction, leads to BEC in a straightforward way. For a density of states of the form G({epsilon}){approx}{epsilon}{sup {gamma}}, the chemical potential {mu} is explicitly calculated as a function of the temperature T and of the number N of bosons, for various significant values of the positive exponent {gamma}. In the thermodynamic limit, in which the boson number N diverges and BEC is a sharp process, the chemical potential {mu} is a singular function of T at the critical temperature T{sub B}, determined by an appropriate critical exponent. The condensate population N{sub 0} is studied analytically and numerically as a function of the temperature, for various values of N and for different {gamma}. This provides an accurate description of the way BEC approaches the character of a sharp phase transition. Some aspects of the real experiments on BEC, involving a finite number of bosons, are also illustrated.

  13. Muonic Chemistry in Condensed Matter

    CERN Multimedia

    2002-01-01

    When polarized muons (@m|+) stop in condensed matter, muonic atoms are formed in the final part of their range, and direct measurements of the @m|+-spin polarization are possible via the asymmetric decay into positrons. The hyperfine interaction determines the characteristic precession frequencies of the @m|+ spin in muonium, @w(Mu). Such frequencies can be altered by the interactions of the muonium's electron spin with the surrounding medium. The measurement of @w(Mu) in a condensed system is known often to provide unique information regarding the system. \\\\ \\\\ In particular, the use of muonium atoms as a light isotope of the simple reactive radical H|0 allows the investigation of fast reactions of radicals over a typical time scale 10|-|9~@$<$~t~@$<$~10|-|5~sec, which is determined by the instrumental resolution at one end and by the @m|+ lifetime at the other. \\\\ \\\\ In biological macromolecules transient radicals, such as the constituents of DNA itself, exist on a time scale of sub-microseconds, acco...

  14. Bio-oil fractionation and condensation

    Science.gov (United States)

    Brown, Robert C; Jones, Samuel T; Pollard, Anthony

    2013-07-02

    A method of fractionating bio-oil vapors which involves providing bio-oil vapors comprising bio-oil constituents is described. The bio-oil vapors are cooled in a first stage which comprises a condenser having passages for the bio-oil separated by a heat conducting wall from passages for a coolant. The coolant in the condenser of the first stage is maintained at a substantially constant temperature, set at a temperature in the range of 75 to 100.degree. C., to condense a first liquid fraction of liquefied bio-oil constituents in the condenser of the first stage. The first liquid fraction of liquified bio-oil constituents from the condenser in the first stage is collected. Also described are steps for subsequently recovering further liquid fractions of liquefied bio-oil constituents. Particular compositions of bio-oil condensation products are also described.

  15. Bio-oil fractionation and condensation

    Science.gov (United States)

    Brown, Robert C.; Jones, Samuel T.; Pollard, Anthony

    2017-04-04

    The present invention relates to a method of fractionating bio-oil vapors which involves providing bio-oil vapors comprising bio-oil constituents. The bio-oil vapors are cooled in a first stage which comprises a condenser having passages for the bio-oil separated by a heat conducting wall from passages for a coolant. The coolant in the condenser of the first stage is maintained at a substantially constant temperature, set at a temperature in the range of 75 to 100.degree. C., to condense a first liquid fraction of liquefied bio-oil constituents in the condenser of the first stage. The first liquid fraction of liquified bio-oil constituents from the condenser in the first stage is collected. Also disclosed are steps for subsequently recovering further liquid fractions of liquefied bio-oil constituents. Particular compositions of bio-oil condensation products are also described.

  16. Condensate from a two-stage gasifier

    DEFF Research Database (Denmark)

    Bentzen, Jens Dall; Henriksen, Ulrik Birk; Hindsgaul, Claus

    2000-01-01

    Condensate, produced when gas from downdraft biomass gasifier is cooled, contains organic compounds that inhibit nitrifiers. Treatment with activated carbon removes most of the organics and makes the condensate far less inhibitory. The condensate from an optimised two-stage gasifier is so clean...... that the organic compounds and the inhibition effect are very low even before treatment with activated carbon. The moderate inhibition effect relates to a high content of ammonia in the condensate. The nitrifiers become tolerant to the condensate after a few weeks of exposure. The level of organic compounds...... and the level of inhibition are so low that condensate from the optimised two-stage gasifier can be led to the public sewer....

  17. Non-iterative model for condensation heat transfer in presence of non-condensable gases inside passive containment cooling vertical tubes

    Energy Technology Data Exchange (ETDEWEB)

    Rosa, Juan Carlos de la [Department of Chemical and Nuclear Engineering, Institute of Energetic Engineering, Polytechnic University of Valencia, Camino de Vera, 14, 46022 Valencia (Spain)], E-mail: juadela3@upvnet.upv.es; Munoz-Cobo, Jose L.; Escriva, Alberto [Department of Chemical and Nuclear Engineering, Institute of Energetic Engineering, Polytechnic University of Valencia, Camino de Vera, 14, 46022 Valencia (Spain)

    2008-01-15

    Some contributions have been stated in order to improve the modeling of concurrent downflow condensation in presence of non-condensables inside vertical tubes. In particular, the influence of non-condensables over the liquid side heat transfer has been considered. The new proposed mechanistic models solve explicitly the real interface temperature by means of a cubic or a fourth order equation. As these models have a non-iterative nature, they can avoid the weakest point of the traditional mechanistic models, which is the slowdown computation if the model had to be implemented in a code. Moreover, as the main non-condensables effects can be accounted for in the heat and mass transfer processes, the new models will be more realistic. The models have been validated with the Vierow experimental data, obtaining a total average relative error, for the fourth order equation method model, of 21% for 268 points.

  18. Depletion of superfluidity in a disordered non-equilibrium quantum condensate

    Energy Technology Data Exchange (ETDEWEB)

    Janot, Alexander; Rosenow, Bernd [Institut fuer Theoretische Physik, Universitaet Leipzig, 04009 Leipzig (Germany); Hyart, Timo [Institute of Physics, Leiden University, Niels Bohrweg 2, 2333 CA Leiden (Netherlands); Eastham, Paul [School of Physics, Trinity College, Dublin 2 (Ireland)

    2013-07-01

    Observations of quantum coherence in driven systems, e.g. polariton condensates, have strongly stimulated experimental as well as theoretical efforts during the last decade. We analyze the superfluid stiffness of a non-equilibrium quantum-condensate in a disordered environment taking gain and loss of particles into account. To this end a modified effective Gross-Pitaevskii equation is employed. We find that the disorder-driven depletion of superfluidity is strongly enhanced due to the gain-loss mechanism. It turns out that the condensate remains stiff at finite length scales only.

  19. Persistent superfluid flow arising from the He-McKellar-Wilkens effect in molecular dipolar condensates

    CERN Document Server

    Wood, A A; Martin, A M

    2016-01-01

    We show that the He-McKellar-Wilkens effect can induce a persistent flow in a Bose-Einstein condensate of polar molecules confined in a toroidal trap, with the dipolar interaction mediated via an electric dipole moment. For Bose-Einstein condensates of atoms with a magnetic dipole moment, we show that although it is theoretically possible to induce persistent flow via the Aharonov-Casher effect, the strength of electric field required is prohibitive. We also outline an experimental geometry tailored specifically for observing the He-McKellar-Wilkens effect in toroidally-trapped condensates.

  20. Quantum depletion of a soliton condensate

    Science.gov (United States)

    Huang, Guoxiang; Deng, L.; Yan, Jiaren; Hu, Bambi

    2006-09-01

    We present rigorous results on the diagonalization of Bogoliubov Hamiltonian for a soliton condensate. Using the complete and orthonormalized set of eigenfunction for the Bogoliubov de Gennes equations, we calculate exactly the quantum depletion of the condensate and show that two degenerate zero-modes, which originate from a U(1) gauge- and a translational-symmetry breaking of the system, induce the quantum diffusion and transverse instability of the soliton condensate.

  1. Light propagation in disordered media: From Maxwell equations to a spherical p-spin model and light condensation effects

    KAUST Repository

    Toth, Laszlo Daniel

    2013-05-01

    The well-known phenomenon of the formation of a Bose-Einstein condensate (BEC), a striking consequence of the Bose-Einstein statistics, has been traditionally linked to an ensemble of ultra-cold gas molecules. However, classical systems can also exhibit condensation effects; in the field of photonics, for example, signatures of this condensation in the mode dynamics (\\'light condensation\\', LC) have been theoretically investigated and experimentally observed in various types of multimode lasers [1,2 and ref. therein]. © 2013 IEEE.

  2. Special issue dedicated to Professor Johann M. Schepers

    Directory of Open Access Journals (Sweden)

    Gideon P De Bruin

    2006-04-01

    Full Text Available It is a great pleasure for me to have been associated with this special issue of the SA Journal of Industrial Psychology dedicated to Professor Johann M. Schepers. The purpose of the special issue is to honour Professor Schepers for his contributions to the development of Psychology and Industrial Psychology as empirical fields of study in South Africa. The contributors have worked with Professor Schepers as students or colleagues and share his academic interests. The articles reflect his areas of interest and employ analytic techniques taught and championed by him. We are grateful to Professor Schepers for his cooperation throughout this project. Thanks are due to all the contributors and referees.

  3. Three professors honored by Virginia Veterinary Medical Association

    OpenAIRE

    Douglas, Jeffrey S.

    2005-01-01

    The Virginia Veterinary Medical Association (VVMA) recently honored three professors from the Virginia-Maryland Regional College of Veterinary Medicine (VMRCVM) during its annual meeting at the Hotel Roanoke.

  4. The Effect of Professor's Attractiveness On Distance Learning Students

    Directory of Open Access Journals (Sweden)

    Jeanny Liu

    2015-07-01

    Full Text Available Technology enabled learning is becoming more popular and pervasive in education. While the effectiveness of distance learning versus traditional classroom education is strongly debated, human factors such as students’ perception of their professors can influence their desire to learn. This research examines the perceptual effect of attractive professors on business students enrolled in distance learning courses. This study expands on prior studies by testing whether the attractiveness of the professor matters to student learning within the context of online learning environment. A total of 122 online business students were surveyed. Our findings suggest that professor’s attractiveness has a statistically significant effect on student learning, motivation, and satisfaction. In addition, online students perceived attractive professors with more expertise as an instructor. Female students had higher motivation than male students. Furthermore, separate analysis indicated that attractiveness effects were stronger for participants over the age 46 when compared to other groups.

  5. Professor Nambu, string theory, and the moonshine phenomenon

    OpenAIRE

    Eguchi, Tohru

    2016-01-01

    I first recall the last occasion I met the late Professor Yoichiro Nambu, in a hospital in Osaka. I then present a brief introduction to a moonshine phenomenon in string theory that have recently come under investigation.

  6. DA Professor Honored for Teaching Excellence With Annual Hamming Award

    OpenAIRE

    Chagoya, Javier

    2017-01-01

    NPS Department of Defense Analysis Associate Professor Heather Gregg is the recipient of the 2017 Richard W. Hamming Annual Faculty Award for Achievement in Teaching, recognizing her exceptional work ... Read More

  7. INTRODUCTION: A TRIBUTE TO PROFESSOR MARJORIE L. GIRTH

    National Research Council Canada - National Science Library

    Armstead C Lewis

    2015-01-01

    ..., professional responsibility, and women's rights. Professor Girth joined the Buffalo Law School faculty in 1971 where she chaired the New York State Bar Association's Banking, Corporation and Business Law Section and was a member of the American Bar...

  8. Interview: Professor Andrew Feinberg speaks to Epigenomics.

    Science.gov (United States)

    Feinberg, Andrew

    2009-10-01

    Andrew Feinberg studied mathematics and humanities at Yale University (CT, USA) in the Directed Studies honors program, and he received his BA (1973) and MD (1976) from the accelerated medical program at Johns Hopkins University (MD, USA), as well as an MPH from Johns Hopkins (1981). He performed a postdoctoral fellowship in developmental biology at the University of California, San Diego (UCSD, CA, USA), clinical training in medicine and medical genetics at the University of Pennsylvania (PA, USA) and genetics research with Bert Vogelstein at Johns Hopkins, discovering altered DNA methylation in human cancer. Dr Feinberg continued to perform seminal work in cancer epigenetics as a Howard Hughes investigator at the University of Michigan (MI, USA), discovering human imprinted genes and loss of imprinting in cancer, and the molecular basis of Beckwith-Wiedemann syndrome. He returned to John Hopkins in 1994 as King Fahd Professor of Medicine, Molecular Biology & Genetics and Oncology, and he holds an Adjunct Professorship at the Karolinska Institute in Sweden. Dr Feinberg is Director of the Center for Epigenetics, a National Human Genome Research Institute-designated Center of Excellence in Genome Sciences. The Center is pioneering genome-scale tools in molecular, statistical and epidemiological epigenetics, and is applying them to the study of cancer, neuropsychiatric disease and aging. As part of the center, Dr Feinberg has organized a highly innovative program to bring gifted minority high-school students into genetics and genomics. Dr Feinberg has also invented a number of widely used molecular tools, including random priming. His honors include election to the American Society for Clinical Investigation, the Association of American Physicians, the Institute of Medicine of the National Academy of Sciences, and the American Academy of Arts and Sciences, as well as membership on the ISI most-cited authors list, a MERIT Award of the National Cancer Institute, a

  9. University Pedagogy for Assistant Professors at Aalborg University (Part 1)

    DEFF Research Database (Denmark)

    Kolmos, Anette; Krogh, Lone

    2003-01-01

    The article describes a course for assistant professors within the University Teacher Education at Aalborg University. The course focus is to develop knowledge, skills and methods from within the didactic, pedagogical, and learning theory-based fields.......The article describes a course for assistant professors within the University Teacher Education at Aalborg University. The course focus is to develop knowledge, skills and methods from within the didactic, pedagogical, and learning theory-based fields....

  10. Sex and Science: How Professor Gender Perpetuates the Gender Gap

    OpenAIRE

    Scott E. Carrell; Marianne E. Page; West, James E.

    2009-01-01

    Why aren't there more women in science? Female college students are currently 37 percent less likely than males to obtain a bachelor's degree in science, technology, engineering, and math (STEM), and comprise only 25 percent of the STEM workforce. This paper begins to shed light on this issue by exploiting a unique dataset of college students who have been randomly assigned to professors over a wide variety of mandatory standardized courses. We focus on the role of professor gender. Our resul...

  11. Emotional exhaustion and burnout among medical professors; a nationwide survey

    OpenAIRE

    Joeri K Tijdink; Vergouwen, Anton CM; Yvo M Smulders

    2014-01-01

    Background Although job-related burnout and its core feature emotional exhaustion are common among medical professionals and compromise job satisfaction and professional performance, they have never been systematically studied in medical professors, who have central positions in academic medicine. Methods We performed an online nationwide survey inviting all 1206 medical professors in The Netherlands to participate. They were asked to fill out the Maslach Burnout Inventory, a ‘professional en...

  12. The Effect of Professor's Attractiveness On Distance Learning Students

    OpenAIRE

    Jeanny Liu; Stella D. Tomasi

    2015-01-01

    Technology enabled learning is becoming more popular and pervasive in education. While the effectiveness of distance learning versus traditional classroom education is strongly debated, human factors such as students’ perception of their professors can influence their desire to learn. This research examines the perceptual effect of attractive professors on business students enrolled in distance learning courses. This study expands on prior studies by testing whether the attractiveness of the ...

  13. Vapor condensation behind the shock wave in vapor-liquid two-phase media

    Science.gov (United States)

    Syoji, Chiharu; Oshiro, Naoto

    Laser extinction, schlieren photography, and in situ pressure measurements are used to characterize vapor condensation behind a shock wave in a diaphragm shock tube with a low-pressure chamber filled with ethanol, water, or freon-11 vapor. The experimental setup is briefly described, and the results are presented graphically and discussed in detail. Condensation, lasting a few hundred microsec before reevaporation sets in, is found to decrease the intensity of the shock front and lower the pressure behind it.

  14. On-Demand Dark Soliton Train Manipulation in a Spinor Polariton Condensate

    KAUST Repository

    Pinsker, F.

    2014-04-10

    We theoretically demonstrate the generation of dark soliton trains in a one-dimensional exciton-polariton condensate within experimentally accessible schemes. In particular, we show that the frequency of the train can be finely tuned fully optically or electrically to provide a stable and efficient output signal modulation. Taking the polarization of the condensate into account, we elucidate the possibility of forming on-demand half-soliton trains. © 2014 American Physical Society.

  15. FOREWORD: The 70th birthday of Professor Stig Stenholm The 70th birthday of Professor Stig Stenholm

    Science.gov (United States)

    Suominen, Kalle-Antti

    2010-09-01

    researchers such as Marc-Andre Dupertuis and Steve Barnett worked with Stig at TFT, and in the 1990s it was the turn of Barry Garraway, Ilkka Tittonen and Nikolay Vitanov among others. For his work in 1992-1997 Stig Stenholm received the prestigious Academy of Finland Professorship which provided him with valuable research funds. My graduation in 1992 was followed by Mackillo Kira in 1995 and Päivi Törmä in 1996. Following developments in the field, in the mid-1990s Stig started to work on Bose-Einstein condensation and quantum information. Later he had a Humboldt fellowship, with stays in Germany shared by the Universities at Konstanz (Jürgen Mlynek) and Ulm (Wolfgang Schleich). Unfortunately, the University of Helsinki decided to replace TFT and a corresponding experimental particle physics institute with a new institute, which was mostly seen as the Finnish front-end for CERN collaboration; in 1997 the Helsinki Institute of Physics (HIP) was started. Although the activities of TFT still existed in the theory section of HIP, many things and especially the atmosphere were changed and in 1997 this partly led Stig to accept a position at the Royal Institute of Technology in Stockholm, Sweden, where two of his Finnish students, Patrik Öhberg and Erika Andersson graduated shortly after the move. I moved to HIP at the time, but left for a position in Turku in 2000, and the quantum optics project was finally switched off at HIP in 2003—only later it was found that quantum optics had provided the Institute with its most cited papers, propelling it into the top 5 percent most cited institutes in its field (especially thanks to Norbert Lütkenhaus and his work on quantum cryptography). The time in Stockholm was fruitful for Stig scientifically, but he also became a member of the Royal Swedish Academy of Sciences, and although Nobel committee papers remain secret for 50 years, it is likely that he had a hand in its activities. In 2005 we jointly published a textbook on quantum

  16. Spontaneous symmetry breaking in spinor Bose-Einstein condensates

    DEFF Research Database (Denmark)

    Scherer, Manuel; Lücke, Bernd; Peise, Jan

    2013-01-01

    We present an analytical model for the theoretical analysis of spin dynamics and spontaneous symmetry breaking in a spinor Bose-Einstein condensate (BEC). This allows for an excellent intuitive understanding of the processes and provides good quantitative agreement with the experimental results...... in the creation efficiency of these atom pairs can be traced back to excitation modes of this confinement. The understanding of these excitation modes allows for a detailed characterization of the symmetry-breaking mechanism, showing how a twofold spontaneous breaking of spatial and spin symmetry can occur....... In addition, a detailed account of the experimental methods for the preparation and analysis of spinor quantum gases is given....

  17. Observation of Weak Collapse in a Bose-Einstein Condensate

    Directory of Open Access Journals (Sweden)

    Christoph Eigen

    2016-12-01

    Full Text Available We study the collapse of an attractive atomic Bose-Einstein condensate prepared in the uniform potential of an optical-box trap. We characterize the critical point for collapse and the collapse dynamics, observing universal behavior in agreement with theoretical expectations. Most importantly, we observe a clear experimental signature of the counterintuitive weak collapse, namely, that making the system more unstable can result in a smaller particle loss. We experimentally determine the scaling laws that govern the weak-collapse atom loss, providing a benchmark for the general theories of nonlinear wave phenomena.

  18. Observation of Weak Collapse in a Bose-Einstein Condensate

    Science.gov (United States)

    Eigen, Christoph; Gaunt, Alexander L.; Suleymanzade, Aziza; Navon, Nir; Hadzibabic, Zoran; Smith, Robert P.

    2016-10-01

    We study the collapse of an attractive atomic Bose-Einstein condensate prepared in the uniform potential of an optical-box trap. We characterize the critical point for collapse and the collapse dynamics, observing universal behavior in agreement with theoretical expectations. Most importantly, we observe a clear experimental signature of the counterintuitive weak collapse, namely, that making the system more unstable can result in a smaller particle loss. We experimentally determine the scaling laws that govern the weak-collapse atom loss, providing a benchmark for the general theories of nonlinear wave phenomena.

  19. Exemplary Chinese University Professors: Qualities and Impact on Students

    Directory of Open Access Journals (Sweden)

    Eugene P. Kim

    2016-03-01

    Full Text Available This study focuses on the qualities of Chinese university professors as perceived by their students and the effects of those qualities on student learning and motivation. Specifically, what qualities and personal characteristics do Chinese university students attribute to their favorite and least favorite professors, and how do those qualities and characteristics affect Chinese university students? Out of 280 students surveyed from three different universities, 226 surveys were completed, returned and included in the final analysis (response rate of 80.7%. The research found that Chinese students favored professors who are entertaining, who help them learn more and who provide them with helpful feedback on their assignments. Students disfavor professors who are boring, arrogant and do not provide helpful feedback or help them learn more. Linear regressions revealed a connection between high quality professors and student learning and motivation. Along with other studies, this research provides evidence that effective university professors are those who not only possess expertise in their fields, but in addition are engaging, student-focused and able to build rapport with their students.

  20. Comparative analysis of an evaporative condenser using artificial neural network and adaptive neuro-fuzzy inference system

    Energy Technology Data Exchange (ETDEWEB)

    Metin Ertunc, H. [Department of Mechatronics Engineering, Kocaeli University, Umuttepe, 41380 Kocaeli (Turkey); Hosoz, Murat [Department of Mechanical Education, Kocaeli University, Umuttepe, 41380 Kocaeli (Turkey)

    2008-12-15

    This study deals with predicting the performance of an evaporative condenser using both artificial neural network (ANN) and adaptive neuro-fuzzy inference system (ANFIS) techniques. For this aim, an experimental evaporative condenser consisting of a copper tube condensing coil along with air and water circuit elements was developed and equipped with instruments used for temperature, pressure and flow rate measurements. After the condenser was connected to an R134a vapour-compression refrigeration circuit, it was operated at steady state conditions, while varying both dry and wet bulb temperatures of the air stream entering the condenser, air and water flow rates as well as pressure, temperature and flow rate of the entering refrigerant. Using some of the experimental data for training, ANN and ANFIS models for the evaporative condenser were developed. These models were used for predicting the condenser heat rejection rate, refrigerant temperature leaving the condenser along with dry and wet bulb temperatures of the leaving air stream. Although it was observed that both ANN and ANFIS models yielded a good statistical prediction performance in terms of correlation coefficient, mean relative error, root mean square error and absolute fraction of variance, the accuracies of ANFIS predictions were usually slightly better than those of ANN predictions. This study reveals that, having an extended prediction capability compared to ANN, the ANFIS technique can also be used for predicting the performance of evaporative condensers. (author)

  1. CALL FOR PAPERS: Special cluster in Biomedical Optics: honouring Professor Valery Tuchin, Saratov University

    Science.gov (United States)

    Wang, Ruikang K.; Priezzhev, Alexander; Fantini, Sergio

    2004-07-01

    To honour Professor Valery Tuchin, one of the pioneers in biomedical optics, Journal of Physics D: Applied Physics invites manuscript submissions on topics in biomedical optics, for publication in a Special section in May 2005. Papers may cover a variety of topics related to photon propagation in turbid media, spectroscopy and imaging. This Special cluster will reflect the diversity, breadth and impact of Professor Tuchin's contributions to the field of biomedical optics over the course of his distinguished career. Biomedical optics is a recently emerged discipline providing a broad variety of optical techniques and instruments for diagnostic, therapeutic and basic science applications. Together with contributions from other pioneers in the field, Professor Tuchin's work on fundamental and experimental aspects in tissue optics contributed enormously to the formation of this exciting field. Although general submissions in biomedical optics are invited, the Special cluster Editors especially encourage submissions in areas that are explicitly or implicitly influenced by Professor Tuchin's contributions to the field of biomedical optics. Manuscripts submitted to this Special cluster of Journal of Physics D: Applied Physics will be refereed according to the normal criteria and procedures of the journal, in accordance with the following schedule: Deadline for receipt of contributed papers: 31 November 2004 Deadline for acceptance and completion of refereeing process: 28 February 2005 Publication of special issue: May 2005 Please submit your manuscript electronically to jphysd@iop.org or via the Web site at www.iop.org/Journals. Otherwise, please send a copy of your typescript, a set of original figures and a cover letter to: The Publishing Administrator, Journal of Physics D: Applied Physics, Institute of Physics Publishing, Dirac House, Temple Back, Bristol BS1 6BE, United Kingdom. Further information on how to submit may be obtained upon request by e-mailing the

  2. Science Academies' 83rd Refresher Course on Experimental Physics

    Indian Academy of Sciences (India)

    IAS Admin

    undergraduate and postgraduate courses in Physics. Participants in this course will gain hands on experience with about 25 experiments designed by Professor R. Srinivasan, the Course Director, Indian Academy of Sciences. Professor R. Srinivasan has conducted such Refresher course in Experimental Physics in more ...

  3. Design and Fabrication of a Hybrid Superhydrophobic-Hydrophilic Surface That Exhibits Stable Dropwise Condensation.

    Science.gov (United States)

    Mondal, Bikash; Mac Giolla Eain, Marc; Xu, QianFeng; Egan, Vanessa M; Punch, Jeff; Lyons, Alan M

    2015-10-28

    Condensation of water vapor is an essential process in power generation, water collection, and thermal management. Dropwise condensation, where condensed droplets are removed from the surface before coalescing into a film, has been shown to increase the heat transfer efficiency and water collection ability of many surfaces. Numerous efforts have been made to create surfaces which can promote dropwise condensation, including superhydrophobic surfaces on which water droplets are highly mobile. However, the challenge with using such surfaces in condensing environments is that hydrophobic coatings can degrade and/or water droplets on superhydrophobic surfaces transition from the mobile Cassie to the wetted Wenzel state over time and condensation shifts to a less-effective filmwise mechanism. To meet the need for a heat-transfer surface that can maintain stable dropwise condensation, we designed and fabricated a hybrid superhydrophobic-hydrophilic surface. An array of hydrophilic needles, thermally connected to a heat sink, was forced through a robust superhydrophobic polymer film. Condensation occurs preferentially on the needle surface due to differences in wettability and temperature. As the droplet grows, the liquid drop on the needle remains in the Cassie state and does not wet the underlying superhydrophobic surface. The water collection rate on this surface was studied using different surface tilt angles, needle array pitch values, and needle heights. Water condensation rates on the hybrid surface were shown to be 4 times greater than for a planar copper surface and twice as large for silanized silicon or superhydrophobic surfaces without hydrophilic features. A convection-conduction heat transfer model was developed; predicted water condensation rates were in good agreement with experimental observations. This type of hybrid superhydrophobic-hydrophilic surface with a larger array of needles is low-cost, robust, and scalable and so could be used for heat

  4. Parametric analysis of a solar still with inverted V-shaped glass condenser

    Directory of Open Access Journals (Sweden)

    Rubio Eduardo

    2015-01-01

    Full Text Available A parametric analysis of a solar still with an inverted V-shaped glass condenser is presented. Results are based on a new mathematical model obtained from a lumped-parameter analysis of the still, with an approach that makes each glass plate of the condensing system sensitive to orientation and depicts its thermal differences. Numerical computations are made to evaluate productivity and temperature differences between the condensing plates as a function of condenser orientation, extinction coefficient and thickness. From this study it was found a significant influence of incident solar radiation on the thermal performance of each condensing plate. Large extinction coefficients and thick glass plates increase absorption losses that result in an appreciable temperature difference. An extinction coefficient of 40 m-1 produces a temperature difference of 2.5°C between both condensers. A glass thickness of 10 mm may increase this temperature difference up to 3.5°C. With respect to the production, due to the still orientation, a difference of 8.7% was found for the condensing plates facing an east-west direction. The proposed model is able to reproduce the temperature and distillate production differences that arise between both condensers in good agreement with experimental data. The overall performance of the still, studied with this new approach, was also in accordance with the widely used traditional models for solar distillation. In addition, the condensing plates parameters of the still can be used to force a differential heating such that for the whole day the temperature of one condensing plate is always higher.

  5. Comparison of Heat Transfer Coefficients of Silver Coated and Chromium Coated Copper Tubes of Condenser in Dropwise Condensation

    OpenAIRE

    Er. Shivesh Kumar; Dr. Amit Kumar

    2016-01-01

    Since centuries steam is being used in power generating system. The steam leaving the power unit is reconverted into water in a condenser designed to transfer heat from the steam to the cooling water as rapidly and as efficiently as possible. The efficiency of condenser depends on rate of condensation and mode of condensation of steam in the condenser. The increase in efficiency of the condenser enhances the heat transfer co-efficient which in turn results in economic design of condenser and ...

  6. The mean condensate heat resistance of dropwise condensation with flowing inert gases

    NARCIS (Netherlands)

    van der Geld, C.W.M.; Brouwers, Jos

    1995-01-01

    The quantification of the condensate heat resistance is studied for dropwise condensation from flowing air-steam mixtures. Flows are essentially laminar and stable with gas Reynolds numbers around 900 and 2000. The condensate shaping up as hemispheres on a plastic plane wall and the presence of

  7. Patterns of mesenchymal condensation in a multiscale, discrete stochastic model.

    Directory of Open Access Journals (Sweden)

    Scott Christley

    2007-04-01

    Full Text Available Cells of the embryonic vertebrate limb in high-density culture undergo chondrogenic pattern formation, which results in the production of regularly spaced "islands" of cartilage similar to the cartilage primordia of the developing limb skeleton. The first step in this process, in vitro and in vivo, is the generation of "cell condensations," in which the precartilage cells become more tightly packed at the sites at which cartilage will form. In this paper we describe a discrete, stochastic model for the behavior of limb bud precartilage mesenchymal cells in vitro. The model uses a biologically motivated reaction-diffusion process and cell-matrix adhesion (haptotaxis as the bases of chondrogenic pattern formation, whereby the biochemically distinct condensing cells, as well as the size, number, and arrangement of the multicellular condensations, are generated in a self-organizing fashion. Improving on an earlier lattice-gas representation of the same process, it is multiscale (i.e., cell and molecular dynamics occur on distinct scales, and the cells are represented as spatially extended objects that can change their shape. The authors calibrate the model using experimental data and study sensitivity to changes in key parameters. The simulations have disclosed two distinct dynamic regimes for pattern self-organization involving transient or stationary inductive patterns of morphogens. The authors discuss these modes of pattern formation in relation to available experimental evidence for the in vitro system, as well as their implications for understanding limb skeletal patterning during embryonic development.

  8. Statistical physics and condensed matter

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2003-07-01

    This document is divided into 4 sections: 1) General aspects of statistical physics. The themes include: possible geometrical structures of thermodynamics, the thermodynamical foundation of quantum measurement, transport phenomena (kinetic theory, hydrodynamics and turbulence) and out of equilibrium systems (stochastic dynamics and turbulence). The techniques involved here are typical of applied analysis: stability criteria, mode decomposition, shocks and stochastic equations. 2) Disordered, glassy and granular systems: statics and dynamics. The complexity of the systems can be studied through the structure of their phase space. The geometry of this phase space is studied in several works: the overlap distribution can now be computed with a very high precision; the boundary energy between low lying states does not behave like in ordinary systems; and the Edward's hypothesis of equi-probability of low lying metastable states is invalidated. The phenomenon of aging, characteristic of glassy dynamics, is studied in several models. Dynamics of biological systems or of fracture is shown to bear some resemblance with that of disordered systems. 3) Quantum systems. The themes include: mesoscopic superconductors, supersymmetric approach to strongly correlated electrons, quantum criticality and heavy fermion compounds, optical sum rule violation in the cuprates, heat capacity of lattice spin models from high-temperature series expansion, Lieb-Schultz-Mattis theorem in dimension larger than one, quantum Hall effect, Bose-Einstein condensation and multiple-spin exchange model on the triangular lattice. 4) Soft condensed matter and biological systems. Path integral representations are invaluable to describe polymers, proteins and self-avoiding membranes. Using these methods, problems as diverse as the titration of a weak poly-acid by a strong base, the denaturation transition of DNA or bridge-hopping in conducting polymers have been addressed. The problems of RNA folding

  9. Assessment and improvement of condensation models in RELAP5/MOD3.2

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Ki Yong; Park, Hyun Sik; Kim, Sang Jae; No, Hee Chen [Korea Advanced Institute of Science and Technology, Taejon (Korea, Republic of)

    1997-12-31

    The condensation models in the standard RELAP5/MOD3.2 code are assessed and improved based on the database, which is constructed from the previous experimental data on various condensation phenomena. The default model of the laminar film condensation in RELAP5/MOD3.2 does not give any reliable predictions, and its alternative model always predicts higher values than the experimental data. Therefore, it is needed to develop a new correlation based on the experimental data of various operating ranges in the constructed database. The Shah correlation, which is used to calculate the turbulent film condensation heat transfer coefficients in the standard RELAP5/MOD3.2, well predicts the experimental data in the database. The horizontally stratified condensation model of RELAP5/MOD3.2 overpredicts both cocurrent and countercurrent experimental data. The correlation proposed by H.J.Kim predicts the database relatively well compared with that of RELAP6/MOD3.2. The RELAP5/MOD3.2 model should use the liquid velocity for the calculation of the liquid Reynolds number and be modified to consider the effects of the gas velocity and the film thickness. 2 refs., 5 figs., 1 tab. (Author)

  10. A new correlation of two-phase frictional pressure drop for condensing flow in pipes

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Yu; Fang, Xiande, E-mail: xd_fang@yahoo.com

    2013-10-15

    Highlights: • Survey of two-phase frictional pressure drop (THFPD) experimental data of condensing flow is conducted. • Applicability of the existing THFPD correlations to condensing flow is assessed. • A new THFPD correlation for condensing flow in pipes is proposed. -- Abstract: The calculation of two-phase frictional pressure drop for condensing flow in pipes is essential in many areas. Although numerous studies concerning this issue have been conducted, an accurate correlation is still required. In this paper, an overall survey of correlations and experimental investigations of two-phase frictional pressure drop is carried out. There 525 experimental data points of 9 refrigerants are gathered from literature, with hydraulic diameter from 0.1 to 10.07 mm, mass flux from 20 to 800 kg/m{sup 2} s, and heat flux from 2 to 55.3 kW/m{sup 2}. The 29 existing correlations are evaluated against the experimental database, among which the best one has a mean absolute relative deviation (MARD) of 25.2%. Based on all the experimental data, a new correlation which has an MARD of 19.4% is proposed, improving significantly the prediction of two-phase frictional pressure drop for pipe condensing flow.

  11. Condensed Matter Theories - Volume 22

    Science.gov (United States)

    Reinholz, Heidi; Röpke, Gerd; de Llano, Manuel

    2007-09-01

    pt. A. Fermi liquids. Pressure comparison between the spherical cellular model and the Thomas-Fermi model / G.A. Baker, Jr. Pair excitations and vertex corrections in Fermi fluids and the dynamic structure function of two-dimension 3He / H.M. Böhm, H. Godfrin, E. Krotscheck, H.J. Lauter, M. Meschke and M. Panholzer. Condensation of helium in wedges / E.S. Hernádez ... [et al.]. Non-Fermi liquid behavior from the Fermi-liquid approach / V.A. Khodel ... [et al.]. Theory of third sound and stability of thin 3He-4He superfluid films / E. Krotscheck and M.D. Miller. Pairing in asymmetrical Fermi systems / K.F. Quader and R. Liao. Ground-state properties of small 3He drops from quantum Monte Carlo simulations / E. Sola, J. Casulleras and J. Boronat. Ground-state energy and compressibility of a disordered two-dimensional electron gas / Tanatar ... [et al.]. Quasiexcitons in photoluminescence of incompressible quantum liquids / A. Wójs, A.G ladysiewicz and J.J. Quinn -- pt. B. Bose liquids. Quantum Boltzmann liquids / K.A. Gernoth, M L. Ristig and T. Lindenau. Condensate fraction in the dynamic structure function of Bose fluids / M. Saarela, F. Mazzanti and V. Apaja -- pt. C. Strongly-correlated electronic systems. Electron gas in high-field nanoscopic transport: metallic carbon nanotubes / F. Green and D. Neilson. Evolution and destruction of the Kondo effect in a capacitively coupled double dot system / D.E. Logan and M.R. Galpin. The method of increments-a wavefunction-based Ab-Initio correlation method for solids / B. Paulus. Fractionally charged excitations on frustrated lattices / E. Runge, F. Pollmann and P. Fulde. 5f Electrons in actinides: dual nature and photoemission spectra / G. Zwicknagl -- pt. D. Magnetism. Magnetism in disordered two-dimensional Kondo-Necklace / W. Brenig. On the de Haas-can Alphen oscillation in 2D / S. Fujita and D.L. Morabito. Dynamics in one-dimensional spin systems-density matrix reformalization group study / S. Nishimoto and M

  12. Forecasting the Student-Professor Matches That Result in Unusually Effective Teaching

    Science.gov (United States)

    Gross, Jennifer; Lakey, Brian; Lucas, Jessica L.; LaCross, Ryan; Plotkowski, Andrea R.; Winegard, Bo

    2015-01-01

    Background: Two important influences on students' evaluations of teaching are relationship and professor effects. Relationship effects reflect unique matches between students and professors such that some professors are unusually effective for some students, but not for others. Professor effects reflect inter-rater agreement that some professors…

  13. Assessment of the controllability of condensible emissions. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Shareef, G.S.; Waddell, J.T.

    1990-10-01

    The report gives results of a study to gain insights into the condensible emissions area from an air toxics perspective, with emphasis on controllability and chemical composition of these emissions. The study: compiled existing data on condensible emissions; determined the chemical composition of condensible emissions, where possible; identified source categories that are major emitters of condensibles; evaluated the effectiveness of various control devices in reducing condensible emissions; and evaluated how the performance of currently available control technologies can be improved to better control condensible emissions. Two data bases were developed: the Condensibles Data Base contains 43 emission source categories; the Specialized Condensibles Data Base focuses on the chemical composition of condensible emissions.

  14. Spontaneous formation of quantized vortices in Bose-Einstein condensates

    Science.gov (United States)

    Weiler, Chad Nathan

    Phase transitions abound in the physical world, from the subatomic length scales of quark condensation to the decoupling forces in the early universe. In the Bose-Einstein condensation phase transition, a gas of trapped bosonic atoms is cooled to a critical temperature. Below this temperature, a macroscopic number of atoms suddenly starts to occupy a single quantum state; these atoms comprise the Bose-Einstein condensate (BEC). The dynamics of the BEC phase transition are the focus of this dissertation and the experiments described here have provided new information on the details of BEC formation. New theoretical developments are proving to be valuable tools for describing BEC phase transition dynamics and interpreting new experimental results. With their amenability to optical manipulation and probing along with the advent of new microscopic theories, BECs provide an important new avenue for gaining insight into the universal dynamics of phase transitions in general. Spontaneous symmetry breaking in the system's order parameter may be one result of cooling through a phase transition. A potential consequence of this is the spontaneous formation of topological defects, which in a BEC appear as vortices. We experimentally observed and characterized the spontaneous formation of vortices during BEC growth. We attribute vortex creation to coherence length limitations during the initial stages of the phase transition. Parallel to these experimental observations, theory collaborators have used the Stochastic Gross-Pitaevski Equation formalism to simulate the growth of a condensate from a thermal cloud. The experimental and theoretical statistical results of the spontaneous formation of vortex cores during the growth of the condensate are in good quantitative agreement with one another, supporting our understanding of the dynamics of the phase transition. We believe that our results are also qualitatively consistent with the Kibble-Zurek mechanism, a universal model for

  15. Heat and mass transfer with condensation in capillary porous bodies.

    Science.gov (United States)

    Larbi, Salah

    2014-01-01

    The purpose of this present work is related to wetting process analysis caused by condensation phenomena in capillary porous material by using a numerical simulation. Special emphasis is given to the study of the mechanism involved and the evaluation of classical theoretical models used as a predictive tool. A further discussion will be given for the distribution of the liquid phase for both its pendular and its funicular state and its consequence on diffusion coefficients of the mathematical model used. Beyond the complexity of the interaction effects between vaporisation-condensation processes on the gas-liquid interfaces, the comparison between experimental and numerical simulations permits to identify the specific contribution and the relative part of mass and energy transport parameters. This analysis allows us to understand the contribution of each part of the mathematical model used and to simplify the study.

  16. Shock wave compression of condensed matter a primer

    CERN Document Server

    Forbes, Jerry W

    2012-01-01

    This book introduces the core concepts of the shock wave physics of condensed matter, taking a continuum mechanics approach to examine liquids and isotropic solids. The text primarily focuses on one-dimensional uniaxial compression in order to show the key features of condensed matter’s response to shock wave loading. The first four chapters are specifically designed to quickly familiarize physical scientists and engineers with how shock waves interact with other shock waves or material boundaries, as well as to allow readers to better understand shock wave literature, use basic data analysis techniques, and design simple 1-D shock wave experiments. This is achieved by first presenting the steady one-dimensional strain conservation laws using shock wave impedance matching, which insures conservation of mass, momentum and energy. Here, the initial emphasis is on the meaning of shock wave and mass velocities in a laboratory coordinate system. An overview of basic experimental techniques for measuring pressure...

  17. Heat and Mass Transfer with Condensation in Capillary Porous Bodies

    Directory of Open Access Journals (Sweden)

    Salah Larbi

    2014-01-01

    Full Text Available The purpose of this present work is related to wetting process analysis caused by condensation phenomena in capillary porous material by using a numerical simulation. Special emphasis is given to the study of the mechanism involved and the evaluation of classical theoretical models used as a predictive tool. A further discussion will be given for the distribution of the liquid phase for both its pendular and its funicular state and its consequence on diffusion coefficients of the mathematical model used. Beyond the complexity of the interaction effects between vaporisation-condensation processes on the gas-liquid interfaces, the comparison between experimental and numerical simulations permits to identify the specific contribution and the relative part of mass and energy transport parameters. This analysis allows us to understand the contribution of each part of the mathematical model used and to simplify the study.

  18. Hydrophilic structures for condensation management in appliances

    Science.gov (United States)

    Kuehl, Steven John; Vonderhaar, John J.; Wu, Guolian; Wu, Mianxue

    2016-02-02

    An appliance that includes a cabinet having an exterior surface; a refrigeration compartment located within the cabinet; and a hydrophilic structure disposed on the exterior surface. The hydrophilic structure is configured to spread condensation. The appliance further includes a wicking structure located in proximity to the hydrophilic structure, and the wicking structure is configured to receive the condensation.

  19. Born-Kothari Condensation for Fermions

    Directory of Open Access Journals (Sweden)

    Arnab Ghosh

    2017-09-01

    Full Text Available In the spirit of Bose–Einstein condensation, we present a detailed account of the statistical description of the condensation phenomena for a Fermi–Dirac gas following the works of Born and Kothari. For bosons, while the condensed phase below a certain critical temperature, permits macroscopic occupation at the lowest energy single particle state, for fermions, due to Pauli exclusion principle, the condensed phase occurs only in the form of a single occupancy dense modes at the highest energy state. In spite of these rudimentary differences, our recent findings [Ghosh and Ray, 2017] identify the foregoing phenomenon as condensation-like coherence among fermions in an analogous way to Bose–Einstein condensate which is collectively described by a coherent matter wave. To reach the above conclusion, we employ the close relationship between the statistical methods of bosonic and fermionic fields pioneered by Cahill and Glauber. In addition to our previous results, we described in this mini-review that the highest momentum (energy for individual fermions, prerequisite for the condensation process, can be specified in terms of the natural length and energy scales of the problem. The existence of such condensed phases, which are of obvious significance in the context of elementary particles, have also been scrutinized.

  20. Mathematical modelling of dropwise condensation on textured ...

    Indian Academy of Sciences (India)

    locations with local minima of the free surface energy. In macroscopic modelling of ..... the substrate area by a random seed generator function in C++ that returns a matrix containing pseudo random numbers ... 2.2b Drop growth by direct condensation: The rate of condensation on the free surface of a drop depends on its ...

  1. Contribution to the study of unsteady condensation in transonic flow; Contribution a l`etude de la condensation instationnaire en ecoulement transsonique

    Energy Technology Data Exchange (ETDEWEB)

    Collignan, B.; Laali, A.R.

    1993-12-01

    The aim of this thesis is the study of transonic steam flows with condensation, especially at high pressure. This study includes a numerical part an experimental one. The modelling has consisted of introducing a spontaneous condensation model in a one-dimensional Euler code using steam-water thermodynamic tables. Calculations, performed with this code, are in good agreement with experimental results at low pressure. The experimental study has been undertaken on a high pressure experimental loop installed at the Bugey nuclear power plant. We have studied steam flows in nozzles. The results obtained show that a partial heterogeneous condensation occurs in these flows. This proportion is stronger if the expansion rate of the flow is low and if the inlet pressure is high. However, a correction factor is obtained for high pressure nucleation rate model from experimental results. No unsteady condensation has been observed for flows between 15 bars and 50 bars with the steam available at Bugey power plant. (authors). figs., 71 refs., 6 annexes.

  2. Condensation phenomenon detection through surface plasmon resonance.

    Science.gov (United States)

    Ibrahim, Joyce; Al Masri, Mostafa; Veillas, Colette; Celle, Frédéric; Cioulachtjian, Serge; Verrier, Isabelle; Lefèvre, Frédéric; Parriaux, Olivier; Jourlin, Yves

    2017-10-02

    The aim of this work is to optically detect the condensation of acetone vapor on an aluminum plate cooled down in a two-phase environment (liquid/vapor). Sub-micron period aluminum based diffraction gratings with appropriate properties, exhibiting a highly sensitive plasmonic response, were successfully used for condensation experiments. A shift in the plasmonic wavelength resonance has been measured when acetone condensation on the aluminum surface takes place due to a change of the surrounding medium close to the surface, demonstrating that the surface modification occurs at the very beginning of the condensation phenomenon. This paper presents important steps in comprehending the incipience of condensate droplet and frost nucleation (since both mechanisms are similar) and thus to control the phenomenon by using an optimized engineered surface.

  3. Polariton condensation in a disordered potential

    DEFF Research Database (Denmark)

    Antón, C.; Tosi, G.; Lingg, C. A.

    2011-01-01

    We study polariton condensation under OPO (Optical Parametric Oscillator) out-of-equilibrium conditions [1] in the presence of linear and point defects. Because of the simultaneous presence of pump, signal and idler emitting at different wave vectors, as well as of photonic disorder, the system....... Furthermore, a detailed study of the condensate phase demonstrates that the map of the supercurrents is unambiguously determined by the different defect geometries. We have studied two similar λ/2 GaAs-based microcavities, differing mainly by the thickness of the cavity and of the quantum well placed...... of a surrounding 2D OPO condensate. A spectral analysis of the real space emission (Fig. 1 (b)) resolves the 2D emission (1.5505 eV) and that of the 1D condensate (1.5500 eV). The linear defect separates the 2D condensate in two parts, each one of them having a different finite momentum pointing towards the low...

  4. Isotope effect on the zero point energy shift upon condensation

    Energy Technology Data Exchange (ETDEWEB)

    Kornblum, Z.C.; Ishida, T.

    1977-07-01

    The various isotope-dependent and independent atomic and molecular properties that pertain to the isotopic difference between the zero point energy (ZPE) shifts upon condensation were derived. The theoretical development of the change of the ZPE associated with the internal molecular vibrations, due to the condensation of the gaseous molecules, is presented on the basis of Wolfsberg's second-order perturbation treatment of the isotope-dependent London dispersion forces between liquid molecules. The isotope effect on the ZPE shift is related to the difference between the sums of the integrated intensities of the infrared absorption bands of the two gaseous isotopic molecules. The effective atomic charges are also calculated from available experimental infrared intensity data. The effects of isotopic substitutions of carbon-13 for carbon-12 and/or deuterium for protium, in ethylene, methane, and the fluorinated methanes, CH/sub 3/F, CH/sub 2/F/sub 2/, CHF/sub 3/, and CF/sub 4/, on the ZPE shift upon condensation are calculated. These results compare well with the Bigeleisen B-factors, which are experimentally obtained from vapor pressure measurements of the isotopic species. Each of the following molecular properties will tend to increase the isotopic difference between the ZPE shifts upon condensation: (1) large number of highly polar bonds, (2) high molecular weight, (3) non-polar (preferably) or massive molecule, (4) non-hydrogenous molecule, and (5) closely packed liquid molecules. These properties will result in stronger dispersion forces in the liquid phase between the lighter molecules than between the isotopically heavier molecules. 36 tables, 9 figures.

  5. 13th International Workshop on Condensed Matter Theories

    CERN Document Server

    1990-01-01

    This volume gathers the invited talks of the XIII International Work­ shop on Condensed Matter Theories which took place in Campos do Jordao near Sao Paulo, Brazil, August 6-12, 1989. It contains contributions in a wide variety of fields including neutral quantum and classical fluids, electronic systems, composite materials, plasmas, atoms, molecules and nuclei, and as this year's workshop reflected the natural preoccupation in materials science with its spectacular prospect for mankind, room tempera­ ture super-conductivity. All topics are treated from a common viewpoint: that of many-body physics, whether theoretical or simu1ational. Since the very first workshop, held at the prestigious Instituto de Fisica Teorica in Sao Paulo, and organized by the same organizer of the 1989 workshop, Professor Valdir Casaca Aguilera-Navarro, the meeting has taken place annually six times in Latin America, four in Europe and three in the United States. Its principal objective has been to innitiate and nurture collaborati...

  6. Theory and simulations of toroidal and rod-like structures in single-molecule DNA condensation.

    Science.gov (United States)

    Cortini, Ruggero; Caré, Bertrand R; Victor, Jean-Marc; Barbi, Maria

    2015-03-14

    DNA condensation by multivalent cations plays a crucial role in genome packaging in viruses and sperm heads, and has been extensively studied using single-molecule experimental methods. In those experiments, the values of the critical condensation forces have been used to estimate the amplitude of the attractive DNA-DNA interactions. Here, to describe these experiments, we developed an analytical model and a rigid body Langevin dynamics assay to investigate the behavior of a polymer with self-interactions, in the presence of a traction force applied at its extremities. We model self-interactions using a pairwise attractive potential, thereby treating the counterions implicitly. The analytical model allows to accurately predict the equilibrium structures of toroidal and rod-like condensed structures, and the dependence of the critical condensation force on the DNA length. We find that the critical condensation force depends strongly on the length of the DNA, and finite-size effects are important for molecules of length up to 10(5)μm. Our Langevin dynamics simulations show that the force-extension behavior of the rod-like structures is very different from the toroidal ones, so that their presence in experiments should be easily detectable. In double-stranded DNA condensation experiments, the signature of the presence of rod-like structures was not unambiguously detected, suggesting that the polyamines used to condense DNA may protect it from bending sharply as needed in the rod-like structures.

  7. Thermal analysis of parallel flow multi pass channel condenser for automotive air conditioning system

    Energy Technology Data Exchange (ETDEWEB)

    Sanaye, S.; Dehghandokht, M. [Iran Univ. of Science and Technology, Tehran (Iran, Islamic Republic of). Dept. of Mechanical Engineering, Energy Systems Improvement Lab; Beigi, H.M.; Bahrami, S. [Sardsaz Khodro Co., Tehran (Iran, Islamic Republic of). Research and Development Div.

    2010-07-01

    The problem of ozone depletion was partly solved by replacing CFC refrigerant with HFC refrigerants. Since the risk of refrigerant leak in automotive air conditioning systems is much greater than that of common air conditioning systems and refrigerators, there is a need to develop new automotive air conditioning systems that consume less power and require less refrigerant. This paper presented and validated the thermal performance of a parallel flow multi-channel condenser developed by Sardsaz Khodro Company. The condenser is a brazed aluminium one with air in cross-flow; the refrigerant circulates inside multi-channel flat tubes composed of 7 parallel ports. The condenser is composed of 4 refrigerant passes and several small channel tubes. The air follows a single cross flow path across louvered fins. A computer program for performance analysis of parallel flow condensers widely used in mobile air conditioning systems, using an empirical equation for the heat transfer coefficient, was developed on the basis of pressure drop. The model was based on an effectiveness-NTU method. The simulated performance results for the condenser heat capacity, refrigerant pressure drop, subcooling at the outlet of condenser and condenser outlet air temperature were close to experimental data results from calorimeter tests. 5 refs., 11 figs.

  8. Numerical investigation of homogeneous condensation in Prandtl-Meyer expansion flows

    Science.gov (United States)

    Cao, Y.; Cheng, W.; Luo, X.; Yang, J.

    2017-03-01

    The effect of heat addition induced by condensation of water vapor on Prandtl-Meyer flows is investigated numerically. Two configurations are considered to study the formation of the stationary waves and the movement of the oscillatory shocks caused by homogeneous condensation. One is a nozzle-shaped channel bounded by lower and upper walls, and the other is an upper unbounded corner expansion. For the first configuration, cases with a sharp corner and a rounded corner are compared to highlight the influence of the sharp corner, where the cooling rate is very large. The density variation in the zone near the corner is smoothed, and the influence on the flow structure caused by the sharp corner is very limited in the neighborhood of the sharp corner. For a relatively low initial saturation, the structures of the condensation shock in the numerical simulation agree well with the experimental results in the literature. The increase of the initial saturation makes the condensation shock move upstream, and eventually leads to an unsteady shock motion. The tendency is similar to that in the condensation process in nozzles. For the unbounded corner expansion, the wave structure forms a two-dimensional distribution. Multiple shock waves are observed in the numerical schlieren image, which are caused by a sequence of quenching (by the condensation shock) and rebuilding (by the Prandtl-Meyer expansion) of the condensation. This mutual interaction can also be recognized by the wavy shape of the nucleation rate distribution.

  9. Light quark masses, chiral condensate and quark-gluon condensate in quenched lattice QCD With exact chiral symmetry

    Energy Technology Data Exchange (ETDEWEB)

    Chiu, T.-W.; Hsieh, T.-H

    2004-03-01

    We determine several quantities in quenched lattice QCD with optimal domain-wall fermion. On the 16{sup 3} x 3{sup 2} lattice at {beta} = 6.0, we determine the parameters (C, {delta}, B) in the pseudoscalar meson mass in quenched chiral perturbation theory (g{sub X}PT). Using these parameters, as well as our lattice spacing a and the experimental inputs of m{sub {pi}} and m{sub K} we determine the light quark masses: M{sub u,d} = 4.4 {+-} 0.3 MeV, and m{sub s} = 98 {+-} 7 MeV, in MSbar at {mu} = 2 GeV. Also, we determine the quark condensate q-barq {<=} -(250 {+-} 3 MeV){sup 3}, and the quark-gluon condensate ggbar{sigma}{sub {mu}}{sub v}q< = -(434 {+-} 4 McV){sup 5}, in MSbar at scale 2 GeV.

  10. Self-condensation of n-(N-propyl)butanimine: NMR and mass spectral analyses and investigation by theoretical calculation

    Energy Technology Data Exchange (ETDEWEB)

    Manfrini, Rozangela Magalhaes; Teixeira, Flavia Rodrigues; Pilo-Veloso, Dorila; Alcantara, Antonio Flavio de Carvalho, E-mail: aalcantara@zeus.qui.ufmg.br [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Inst. de Ciencias Exatas. Dept. de Quimica; Nelson, David Lee [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Fac. de Farmacia. Dept. de Quimica; Siqueira, Ezequias Pessoa de [Centro de Pesquisas Rene Rachou (FIOCRUZ), Belo Horizonte, MG (Brazil)

    2012-07-01

    The stability of N-propylbutanimine (1) was investigated under different experimental conditions. The acid-catalyzed self-condensation that produced the E-enimine (4) and Z-inimine (5) was studied by experimental analyses and theoretical calculations. Since the calculations for the energy of 5 indicated that it had a lower energy than 4, yet 4 was the principal product, the self-condensation of 1 must be kinetically controlled. (author)

  11. Professor-psicopedagogo: o que este profissional faz na escola

    Directory of Open Access Journals (Sweden)

    Caroline Andrea Pottker

    Full Text Available Este estudo teve como objetivo identificar o porquê da presença do professor-psicopedagogo nas escolas e qual a função que este desempenha dentro delas, bem como, suas implicações no processo ensino-aprendizagem. Para tanto, foram entrevistados dez professores-psicopedagogos, pertencentes a cinco escolas localizadas no Estado do Paraná. Os resultados apontaram que o cargo de professor-psicopedagogo foi ocupado por professores que tinham o título de especialista em Psicopedagogia, os quais passaram a realizar avaliações psicopedagógicas dos alunos com dificuldades de aprendizagem. Segundo a maioria desses profissionais, uma de suas funções constitui-se em auxiliar o professor que apresenta em sala de aula alunos com dificuldades de aprendizagem, assim como tentar compreender o porquê de estes alunos não estarem aprendendo, sobretudo, ajudá-los na reversão desta problemática. Concluímos que a atuação deste profissional nestas escolas pouco tem contribuído para resolução das dificuldades de aprendizagem, pois centram-se no indivíduo e não no processo ensino-aprendizagem.

  12. Numerical study on condensation heat transfer of trapezoid grooved surfaces

    Directory of Open Access Journals (Sweden)

    Baojin Qi

    2016-05-01

    Full Text Available This article presents a numerical analysis and experimental study on condensation heat transfer and fluid flow for filmwise condensation on trapezoid grooved surfaces. First, a physical model was properly simplified based on some reasonable assumptions. Then, the coupled non-linear governing equations for the mass transfer, fluid flow, and two-dimensional thermal conduction were developed. The relationship between z-coordinate and heat transfer was obtained by solving the equations numerically. The influences of groove length and basic angle were discussed. The calculation results showed that the heat flux decreased with increase in groove length, and the decline range also decreased gradually. The calculation results also suggested that the heat flux through groove with α = 60° was lower than the groove with α = 75° at the top of the groove, while the opposite conclusion was obtained at the low parts. The distributions of wall temperature and heat flux on trapezoid groove were also studied systematically. The distribution of surface temperature and heat flux presents obvious lateral inhomogeneity, and the maximum wall temperature and heat flux were both obtained in region II. The thermal resistance of groove with α = 60° was lower but the liquid-discharged ability was better than that of groove with α = 75°. In order to validate the feasibility and reliability of the present analyses and to further investigate the heat transfer performance of trapezoid grooved surfaces, experiments were carried out with three condensing plates including two trapezoid grooved surfaces in different physical dimensions and one smooth surface. The experimental data obtained under various schooling were compared with the calculations, and the experimental results for different condensing plates are all in good agreement with the numerical model, with a maximum deviation less than 15%. Moreover, the trapezoid grooves can enhance the

  13. A Comprehensive Model of Electric-Field-Enhanced Jumping-Droplet Condensation on Superhydrophobic Surfaces.

    Science.gov (United States)

    Birbarah, Patrick; Li, Zhaoer; Pauls, Alexander; Miljkovic, Nenad

    2015-07-21

    Superhydrophobic micro/nanostructured surfaces for dropwise condensation have recently received significant attention due to their potential to enhance heat transfer performance by shedding positively charged water droplets via coalescence-induced droplet jumping at length scales below the capillary length and allowing the use of external electric fields to enhance droplet removal and heat transfer, in what has been termed electric-field-enhanced (EFE) jumping-droplet condensation. However, achieving optimal EFE conditions for enhanced heat transfer requires capturing the details of transport processes that is currently lacking. While a comprehensive model has been developed for condensation on micro/nanostructured surfaces, it cannot be applied for EFE condensation due to the dynamic droplet-vapor-electric field interactions. In this work, we developed a comprehensive physical model for EFE condensation on superhydrophobic surfaces by incorporating individual droplet motion, electrode geometry, jumping frequency, field strength, and condensate vapor-flow dynamics. As a first step toward our model, we simulated jumping droplet motion with no external electric field and validated our theoretical droplet trajectories to experimentally obtained trajectories, showing excellent temporal and spatial agreement. We then incorporated the external electric field into our model and considered the effects of jumping droplet size, electrode size and geometry, condensation heat flux, and droplet jumping direction. Our model suggests that smaller jumping droplet sizes and condensation heat fluxes require less work input to be removed by the external fields. Furthermore, the results suggest that EFE electrodes can be optimized such that the work input is minimized depending on the condensation heat flux. To analyze overall efficiency, we defined an incremental coefficient of performance and showed that it is very high (∼10(6)) for EFE condensation. We finally proposed mechanisms

  14. Condensation-Fouling Interaction in Low-Temperature EGR-Coolers

    Directory of Open Access Journals (Sweden)

    Reißig Martin

    2014-01-01

    Full Text Available EGR cooling is a worthwhile technology capable of reducing NOx-emissions and increasing the efficiency of CI engines. Challenges arise when low-temperature cooling is applied with high fuel sulfur contents. The resulting sulfuric acid condenses in conjunction with the water of the exhaust gas and gives rise to corrosion of coolers and engine components. Additionally, fouling of the EGR cooler is exacerbated by the condensation of acidic components compromising EGR performance. In order to gain a better understanding of the underlying processes a combined experimental and model-based approach is presented. Tests of two different EGR-cooler concepts under various conditions showed a strong influence of the fuel sulfur content on fouling and condensation. The one-dimensional cooler model developed alongside these experiments consists of an activity coefficient model (NRTL of the binary system water - sulfuric acid and a condensation model that allows for simulating the coupled condensation of both vapor components. Comparison of experimental fouling and simulated condensation results show good agreement in interpreting critical fouling phenomena that occur at temperatures in between the acid-water dew point and the dew point of pure water.

  15. EXPERIMENTAL STUDY IN NATURAL CONVECTION

    African Journals Online (AJOL)

    PROF. BARTH EKWEME

    climatic conditions are favorable for the development of solar chimneys for the production of electrical energy or the drying of agro-food products. 1.1 Experimental models. The first prototype tower was built in Manzanares in. 1981, thanks to the team of Professor Schlaich, Haaf et al., (1983); Haaf et al., (1984), in Spain.

  16. Growth and wetting of water droplet condensed between micron-sized particles and substrate.

    Science.gov (United States)

    Quang, Tran Si Bui; Leong, Fong Yew; An, Hongjie; Tan, Beng Hau; Ohl, Claus-Dieter

    2016-08-04

    We study heterogeneous condensation growth of water droplets on micron-sized particles resting on a level substrate. Through numerical simulations on equilibrium droplet profiles, we find multiple wetting states towards complete wetting of the particle. Specifically, a partially wetting droplet could undergo a spontaneous transition to complete wetting during condensation growth, for contact angles above a threshold minimum. In addition, we find a competitive wetting behavior between the particle and the substrate, and interestingly, a reversal of the wetting dependence on contact angles during late stages of droplet growth. Using quasi-steady assumption, we simulate a growing droplet under a constant condensation flux, and the results are in good agreement with our experimental observations. As a geometric approximation for particle clusters, we propose and validate a pancake model, and with it, show that a particle cluster has greater wetting tendency compared to a single particle. Together, our results indicate a strong interplay between contact angle, capillarity and geometry during condensation growth.

  17. Production of rubidium Bose-Einstein condensate in an optically-plugged magnetic quadrupole trap

    CERN Document Server

    Zhang, Dong-Fang; Kong, Ling-Ran; Li, Kai; Jiang, Kai-Jun

    2016-01-01

    We have experimentally produced rubidium Bose-Einstein condensate in an optically-plugged magnetic quadrupole (OPQ) trap. A far blue-detuned focused laser beam with a wavelength of 532 nm is plugged in the center of the magnetic quadrupole trap to increase the number of trapped atoms and suppress the heating. A radio frequency (RF) evaporative cooling in the magneto-optical hybrid trap is applied to decrease the atom temperature into degeneracy. The atom number of the condensate is $1.2(0.4)\\times10^5$ and the temperature is below 100 nK. We have also studied characteristic behaviors of the condensate, such as phase space density (PSD), condensate fraction and anisotropic expansion.

  18. Thermodynamics and Dynamics of Bose condensation in a quasi-homogeneous gas

    Science.gov (United States)

    Navon, Nir; Schmidutz, Tobias; Gotlibovych, Igor; Gaunt, Alexander; Robert-de-Saint-Vincent, Martin; Smith, Robert; Hadzibabic, Zoran

    2014-05-01

    We present an experimental study of the thermodynamics and dynamics of Bose-Einstein condensation (BEC) in an optical-box trap. We first characterize the critical point for BEC, and observe saturation of the thermal component in a partially condensed cloud, in agreement with Einstein's textbook picture of a purely statistical phase transition. We also observed the quantum Joule-Thomson effect, namely isoenthalpic cooling of a non-interacting gas. We then investigate the dynamics of Bose condensation in the box potential following a rapid temperature quench through the phase transition, and focus on the time-evolution of the condensed fraction, the coherence length and the mean-field shift, that we probe via Bragg spectroscopy.

  19. Topology and condensed matter physics

    CERN Document Server

    Mj, Mahan; Bandyopadhyay, Abhijit

    2017-01-01

    This book introduces aspects of topology and applications to problems in condensed matter physics. Basic topics in mathematics have been introduced in a form accessible to physicists, and the use of topology in quantum, statistical and solid state physics has been developed with an emphasis on pedagogy. The aim is to bridge the language barrier between physics and mathematics, as well as the different specializations in physics. Pitched at the level of a graduate student of physics, this book does not assume any additional knowledge of mathematics or physics. It is therefore suited for advanced postgraduate students as well. A collection of selected problems will help the reader learn the topics on one's own, and the broad range of topics covered will make the text a valuable resource for practising researchers in the field.  The book consists of two parts: one corresponds to developing the necessary mathematics and the other discusses applications to physical problems. The section on mathematics is a qui...

  20. Stellar matter with pseudoscalar condensates

    Energy Technology Data Exchange (ETDEWEB)

    Andrianov, A.A. [Saint-Petersburg State University, St. Petersburg (Russian Federation); Universitat de Barcelona, Departament d' Estructura i Constituents de la Materia and Institut de Ciencies del Cosmos (ICCUB), Barcelona, Catalonia (Spain); Andrianov, V.A.; Kolevatov, S.S. [Saint-Petersburg State University, St. Petersburg (Russian Federation); Espriu, D. [Universitat de Barcelona, Departament d' Estructura i Constituents de la Materia and Institut de Ciencies del Cosmos (ICCUB), Barcelona, Catalonia (Spain)

    2016-03-15

    In this work we consider how the appearance of gradients of pseudoscalar condensates in dense systems may possibly influence the transport properties of photons in such a medium as well as other thermodynamic characteristics. We adopt the hypothesis that in regions where the pseudoscalar density gradient is large the properties of photons and fermions are governed by the usual lagrangian extended with a Chern-Simons interaction for photons and a constant axial field for fermions. We find that these new pieces in the lagrangian produce non-trivial reflection coefficients both for photons and fermions when entering or leaving a region where the pseudoscalar has a non-zero gradient. A varying pseudoscalar density may also lead to instability of some fermion and boson modes and modify some properties of the Fermi sea. We speculate that some of these modifications could influence the cooling rate of stellar matter (for instance in compact stars) and have other observable consequences. While quantitative results may depend on the precise astrophysical details most of the consequences are quite universal and consideration should be given to this possibility. (orig.)

  1. Direct contact condensation in packed beds

    Energy Technology Data Exchange (ETDEWEB)

    Li, Yi; Klausner, James F.; Mei, Renwei; Knight, Jessica [Department of Mechanical and Aerospace Engineering, University of Florida, Gainesville, FL 32611 (United States)

    2006-12-15

    A diffusion driven desalination process was recently described where a very effective direct contact condenser with a packed bed is used to condense water vapor out of an air/vapor mixture. A laboratory scale direct contact condenser has been fabricated as a twin tower structure with two stages, co-current and countercurrent. Experiments have been operated in each stage with respective saturated air inlet temperatures of 36, 40 and 43{sup o}C. The temperature and humidity data have been collected at the inlet and exit of the packed bed for different water to air mass flow ratios that vary between 0 and 2.5. A one-dimensional model based on conservation principles has been developed, which predicts the variation of temperature, humidity, and condensation rate through the condenser stages. Agreement between the model and experiments is very good. It is observed that the countercurrent flow stage condensation effectiveness is significantly higher than that for the co-current stage. The condensation heat and mass transfer rates were found to decrease when water blockages occur within the packed bed. Using high-speed digital cinematography, it was observed that this problem can occur at any operating condition, and is dependent on the packing surface wetting characteristics. This observation is used to explain the requirement for two different empirical constants, depending on packing diameter, suggested by Onda for the air side mass transfer coefficient correlation. (author)

  2. Low-temperature Condensation of Carbon

    Science.gov (United States)

    Krasnokutski, S. A.; Goulart, M.; Gordon, E. B.; Ritsch, A.; Jäger, C.; Rastogi, M.; Salvenmoser, W.; Henning, Th.; Scheier, P.

    2017-10-01

    Two different types of experiments were performed. In the first experiment, we studied the low-temperature condensation of vaporized graphite inside bulk liquid helium, while in the second experiment, we studied the condensation of single carbon atoms together with H2, H2O, and CO molecules inside helium nanodroplets. The condensation of vaporized graphite leads to the formation of partially graphitized carbon, which indicates high temperatures, supposedly higher than 1000°C, during condensation. Possible underlying processes responsible for the instant rise in temperature during condensation are discussed. This suggests that such processes cause the presence of partially graphitized carbon dust formed by low-temperature condensation in the diffuse interstellar medium. Alternatively, in the denser regions of the ISM, the condensation of carbon atoms together with the most abundant interstellar molecules (H2, H2O, and CO), leads to the formation of complex organic molecules (COMs) and finally organic polymers. Water molecules were found not to be involved directly in the reaction network leading to the formation of COMs. It was proposed that COMs are formed via the addition of carbon atoms to H2 and CO molecules ({{C}}+{{{H}}}2\\to {HCH},{HCH}+{CO}\\to {{OCCH}}2). Due to the involvement of molecular hydrogen, the formation of COMs by carbon addition reactions should be more efficient at high extinctions compared with the previously proposed reaction scheme with atomic hydrogen.

  3. PROFESSOR DR. ION PIŞOTA (1925 – 2008

    Directory of Open Access Journals (Sweden)

    Liliana ZAHARIA

    2009-12-01

    Full Text Available Professor Ion Pişota was born on June 6, 1925, in Hrupiştea, a small settlement in Greek Macedonia, from where he and his family came to Romania in 1927, where he got Romanian citizenship. Between 1941 and 1945, he attended the Tulcea Boys High School and later on, in 1947 he entered the Faculty of Geology – Geography at the University of Bucharest, where he continued to excel until 1951, when he graduated. In the fall of 1950, he took up a tutor position in the field of Hydrolgy at the same faculty passing subsequently through all the stages of academic hierarchy until he became, in 1971, a University Professor. Even after he retired, in 1996, he continued his academic activity as a consultant professor within the same department and faculty that he served with passion and devotion for more than 50 years.

  4. Categorization of Quantum Mechanics Problems by Professors and Students

    CERN Document Server

    Lin, Shih-Yin

    2016-01-01

    We discuss the categorization of 20 quantum mechanics problems by physics professors and undergraduate students from two honors-level quantum mechanics courses. Professors and students were asked to categorize the problems based upon similarity of solution. We also had individual discussions with professors who categorized the problems. Faculty members' categorizations were overall rated higher than those of students by three faculty members who evaluated all of the categorizations. The categories created by faculty members were more diverse compared to the categories they created for a set of introductory mechanics problems. Some faculty members noted that the categorization of introductory physics problems often involves identifying fundamental principles relevant for the problem, whereas in upper-level undergraduate quantum mechanics problems, it mainly involves identifying concepts and procedures required to solve the problem. Moreover, physics faculty members who evaluated others' categorizations express...

  5. Faculty Agency in Applying for Promotion to Professor

    Directory of Open Access Journals (Sweden)

    Susan K. Gardner

    2017-02-01

    Full Text Available Aim/Purpose: In the United States, faculty who wish to pursue promotion to the rank of professor do so without clear guidance or structure. Even the timing of such a process is nebulous. As such, an individual engages in agentic action to pursue the rank. Background: This study examined the experiences of faculty members who chose to pursue the application process to be promoted to professor but were rejected or dissuaded. Methodology: Utilizing a case study of one institutional setting, we conducted 10 in-depth qualitative interviews. Contribution: Very little is known about the process of promotion to full professor in the U.S. and even less empirical research exists. This study advances knowledge of the process and the experiences of those undertaking it. Findings: We learned that cues from the social context greatly influenced these faculty members’ sense of agency.

  6. [Professor Frantisek Por MD and Professor Robert Klopstock MD, students at Budapest and Prague Faculties of Medicine].

    Science.gov (United States)

    Mydlík, M; Derzsiová, K

    2010-11-01

    Professor Frantisek Por MD and Professor Robert Klopstock MD were contemporaries, both born in 1899, one in Zvolen, the other in Dombovar, at the time of Austro-Hungarian Monarchy. Prof. Por attended the Faculty of Medicine in Budapest from 1918 to 1920, and Prof. Klopstock studied at the same place between 1917 and 1919. From 1920 until graduation on 6th February 1926, Prof. Por continued his studies at the German Faculty of Medicine, Charles University in Prague. Prof. Klopstock had to interrupt his studies in Budapest due to pulmonary tuberculosis; he received treatment at Tatranske Matliare where he befriended Franz Kafka. Later, upon Kafka's encouragement, he changed institutions and continued his studies at the German Faculty of Medicine, Charles University in Prague, where he graduated the first great go. It is very likely that, during their studies in Budapest and Prague, both professors met repeatedly, even though their life paths later separated. Following his graduation, Prof. Por practiced as an internist in Prague, later in Slovakia, and from 1945 in Kosice. In 1961, he was awarded the title of university professor of internal medicine at the Faculty of Medicine, Pavol Jozef Safarik University in Kosice, where he practiced until his death in 1980. Prof. Klopstock continued his studies in Kiel and Berlin. After his graduation in 1933, he practiced in Berlin as a surgeon and in 1938 left for USA. In 1962, he was awarded the title of university professor of pulmonary surgery in NewYork, where he died in 1972.

  7. Bimodal condensation silicone elastomers as dielectric elastomers

    DEFF Research Database (Denmark)

    Yu, Liyun; Madsen, Frederikke Bahrt; Skov, Anne Ladegaard

    unimodal refers to that there is one polymer only in the system. As an alternative to unimodal networks there are the bimodal networks where two polymers with significantly different molecular weights are mixed with one crosslinker. [2]Silicone rubber can be divided into condensation type and addition type...... according to the curing reaction. The advantages of condensation silicones compared to addition are the relatively low cost, the curing rate largely being independent of temperature, the excellent adhesion, and the catalyst being nontoxic. [3]In this work, a series of bimodal condensation silicone...

  8. Capillary condensation between disks in two dimensions

    DEFF Research Database (Denmark)

    Gil, Tamir; Ipsen, John Hjorth

    1997-01-01

    Capillary condensation between two two-dimensional wetted circular substrates (disks) is studied by an effective free energy description of the wetting interface. The interfacial free-energy potential is developed on the basis of the theory for the wetting of a single disk, where interfacial...... capillary fluctuations play a dominant role. A simple approximative analytical expression of the interfacial free energy is developed and is validated numerically. The capillary condensation is characterized by the analysis of the coverage of the condensed phase, its stability, and asymptotic behaviors...

  9. Preoperational test report, primary ventilation condensate system

    Energy Technology Data Exchange (ETDEWEB)

    Clifton, F.T.

    1997-01-29

    Preoperational test report for Primary Ventilation Condensate System, Project W-030. Project W-030 provides a ventilation upgrade for the four Aging Waste Facility tanks. The system provides a collection point for condensate generated by the W-030 primary vent offgas cooling system serving tanks AYIOI, AY102, AZIOI, AZI02. The system is located inside a shielded ventilation equipment cell and consists of a condensate seal pot, sampling features, a drain line to existing Catch Tank 241-AZ-151, and a cell sump jet pump. The tests verify correct system operation and correct indications displayed by the central Monitor and Control System.

  10. Condensation of bosons in kinetic regime

    OpenAIRE

    Semikoz, D.V.; Tkachev, I. I.

    1995-01-01

    We study the kinetic regime of the Bose-condensation of scalar particles with weak $\\lambda \\phi^4$ self-interaction. The Boltzmann equation is solved numerically. We consider two kinetic stages. At the first stage the condensate is still absent but there is a nonzero inflow of particles towards ${\\bf p} = {\\bf 0}$ and the distribution function at ${\\bf p} ={\\bf 0}$ grows from finite values to infinity in a finite time. We observe a profound similarity between Bose-condensation and Kolmogorov...

  11. Condenser retubing-criteria manual. [PWR; BWR

    Energy Technology Data Exchange (ETDEWEB)

    Impagliazzo, A.M.; Bell, R.J.; Curlett, P.L.; Gordon, H.L.

    1982-05-01

    The objective of this document is to provide engineering assistance to utilities involved in retubing steam surface condensers with corrosion-resistant materials, such as titanium, and the recently developed high alloy pit-resistant steels. Field tests and recent operating experience have shown titanium and at least one of the high alloy pit-resistant steels to be virtually immune to the usual forms of corrosion occurring in steam surface condensers. This, together with the trend toward elimination of copper alloys in the circulating water system, has caused many utilities to retube their condensers with these materials.

  12. Metallization of molecular condensates and superconductivity

    CERN Document Server

    Bogomolov, V N

    2002-01-01

    The possibility of explaining the light absorption by xenon metallization under the pressure as a transition into the superconducting state is considered. The energy structure of the Van der Waals condensates is considered. It is supposed, that by compression of such samples and decrease in the interatomic distances in the Fermi metals and the Van der Waals dielectrics the condensate gets into the area of the superconducting state. This is the area of the binding energies 40-60 kJ/mol. Many of the molecular condensates and metals are close to this area of instability

  13. Active condensation of water by plants

    Directory of Open Access Journals (Sweden)

    Prokhorov Alexey Anatolievich

    2013-10-01

    Full Text Available This paper is devoted to some peculiarities of water condensation on the surface of plants . Arguments in support of the hypothesis that in decreasing temperature of leaves and shoots below the dew point, the plant can actively condense moisture from the air, increasing the duration of dewfall are presented. Evening dewfall on plant surfaces begins before starting the formation of fog. Morning condensation continues for some time after the air temperature exceeds the dew point . The phenomenon in question is found everywhere, but it is particularly important for plants in arid ecosystems.

  14. QCD condensates in ADS/QCD

    DEFF Research Database (Denmark)

    Bechi, Jacopo

    2009-01-01

    This paper focuses on some issues about condensates and renormalization in AdS/QCD models. In particular we consider the consistency of the AdS/QCD approach for scale dependent quantities as the chiral condensate questioned in some recent papers and the 4D meaning of the 5D cosmological constant...... in a model in which the QCD is dual to a 5D gravity theory. We will be able to give some arguments that the cosmological constant is related to the QCD gluon condensate....

  15. Enhanced Evaporation and Condensation in Tubes

    Science.gov (United States)

    Honda, Hiroshi

    A state-of-the-art review of enhanced evaporation and condensation in horizontal microfin tubes and micro-channels that are used for air-conditioning and refrigeration applications is presented. The review covers the effects of flow pattern and geometrical parameters of the tubes on the heat transfer performance. Attention is paid to the effect of surface tension which leads to enhanced evaporation and condensation in the microfin tubes and micro-channels. A review of prior efforts to develop empirical correlations of the heat transfer coefficient and theoretical models for evaporation and condensation in the horizontal microfin tubes and micro-channels is also presented.

  16. Multi-shell model of ion-induced nucleic acid condensation

    Science.gov (United States)

    Tolokh, Igor S.; Drozdetski, Aleksander V.; Pollack, Lois; Onufriev, Alexey V.

    2016-01-01

    We present a semi-quantitative model of condensation of short nucleic acid (NA) duplexes induced by trivalent cobalt(iii) hexammine (CoHex) ions. The model is based on partitioning of bound counterion distribution around single NA duplex into “external” and “internal” ion binding shells distinguished by the proximity to duplex helical axis. In the aggregated phase the shells overlap, which leads to significantly increased attraction of CoHex ions in these overlaps with the neighboring duplexes. The duplex aggregation free energy is decomposed into attractive and repulsive components in such a way that they can be represented by simple analytical expressions with parameters derived from molecular dynamic simulations and numerical solutions of Poisson equation. The attractive term depends on the fractions of bound ions in the overlapping shells and affinity of CoHex to the “external” shell of nearly neutralized duplex. The repulsive components of the free energy are duplex configurational entropy loss upon the aggregation and the electrostatic repulsion of the duplexes that remains after neutralization by bound CoHex ions. The estimates of the aggregation free energy are consistent with the experimental range of NA duplex condensation propensities, including the unusually poor condensation of RNA structures and subtle sequence effects upon DNA condensation. The model predicts that, in contrast to DNA, RNA duplexes may condense into tighter packed aggregates with a higher degree of duplex neutralization. An appreciable CoHex mediated RNA-RNA attraction requires closer inter-duplex separation to engage CoHex ions (bound mostly in the “internal” shell of RNA) into short-range attractive interactions. The model also predicts that longer NA fragments will condense more readily than shorter ones. The ability of this model to explain experimentally observed trends in NA condensation lends support to proposed NA condensation picture based on the multivalent

  17. Effect of light assisted collisions on matter wave coherence in superradiant Bose-Einstein condensates

    DEFF Research Database (Denmark)

    Kampel, Nir Shlomo; Griesmaier, Axel Rudolf; Steenstrup, Mads Peter Hornbak

    2012-01-01

    We investigate experimentally the effects of light assisted collisions on the coherence between momentum states in Bose-Einstein condensates. The onset of superradiant Rayleigh scattering serves as a sensitive monitor for matter-wave coherence. A subtle interplay of binary and collective effects...... leads to a profound asymmetry between the two sides of the atomic resonance and provides far bigger coherence loss rates for a condensate bathed in blue detuned light than previously estimated. We present a simplified quantitative model containing the essential physics to explain our experimental data...

  18. Aspectos gerais da formação de professores

    Directory of Open Access Journals (Sweden)

    Edson do Carmo Inforsato

    1996-08-01

    Full Text Available Este artigo, ancorado em estudos recentes e antigos, mostra o afastamento dos cursos de formação de professores em relação aos elementos que compõem a prática profissional docente. Favorável a uma aproximação efetiva com o contexto das práticas de sala de aula, o autor defende a idéia de uma formação de professores atrelada aos problemas e necessidades da prática docente no ensino formal de 1º e 2º graus.

  19. O papel do formador no processo reflexivo de professores

    OpenAIRE

    Altarugio Helena, M.

    2009-01-01

    Este trabalho pretende discutir as práticas e os discursos de uma formadora de professores de ciências, experiente e bem sucedida na formação inicial e continuada. Nossa hipótese é a de que, além dos conhecimentos e das técnicas, é na relação intersubjetiva construída entre a formadora e o grupo de professores, que se encontram os elementos que irão sustentar o processo de formação docente. A partir do modo singular da formadora de enfrentar sua tarefa educativa e lidar com as dificuldades do...

  20. Preditores da Síndrome de Burnout em professores

    Directory of Open Access Journals (Sweden)

    Mary Sandra Carlotto

    Full Text Available O objetivo deste estudo foi identificar os preditores da Síndrome de Burnout em 563 professores de instituições educacionais particulares da região metropolitana de Porto Alegre - RS. Foram utilizados um questionário elaborado para levantamento de variáveis demográficas e profissionais, o Maslach Burnout Inventory, o Job Diagnostic Survey e o Questionário de Satisfação no Trabalho S20/23. Os resultados evidenciam que variáveis relacionadas ao contexto laboral predominam no modelo explicativo de Burnout em professores em ambos os grupos.

  1. Apoio social e fatores associados com a disfonia em professores

    OpenAIRE

    Ceballos,Albanita Gomes da Costa de

    2009-01-01

    p. 1-68 Fatores relacionados com o ambiente e a organização do trabalho, além de fatores próprios do sujeito têm se mostrado associados ao adoecimento vocal de professores. O objetivo deste estudo foi analisar os fatores associados a disfonia nesta categoria profissional e investigar a contribuição do apoio social no processo de adoecimento vocal de professores. Foram pesquisados 476 docentes de escolas municipais de quatro regionais de educação da cidade de Salvador – Bahia. A coleta de d...

  2. Condensed Matter Theories: Volume 25

    Science.gov (United States)

    Ludeña, Eduardo V.; Bishop, Raymond F.; Iza, Peter

    2011-03-01

    dynamics and density functional theory. Exchange-correlation functionals from the identical-particle Ornstein-Zernike equation: Basic formulation and numerical algorithms / R. Cuevas-Saavedra and P. W. Ayers. Features and catalytic properties of RhCu: A review / S. Gonzalez, C. Sousa and F. Illas. Kinetic energy functionals: Exact ones from analytic model wave functions and approximate ones in orbital-free molecular dynamics / V. V. Karasiev ... [et al.]. Numerical analysis of hydrogen storage in carbon nanopores / C. Wexler ... [et al.] -- pt. F. Superconductivity. Generalized Bose-Einstein condensation in superconductivity / M. de Llano. Kohn anomaly energy in conventional superconductors equals twice the energy of the superconducting gap: How and why? / R. Chaudhury and M. P. Das. Collective excitations in superconductors and semiconductors in the presence of a condensed phase / Z. Koinov. Thermal expansion of ferromagnetic superconductors: Possible application to UGe[symbol] / N. Hatayama and R. Konno. Generalized superconducting gap in a Boson-Fermion model / T. A. Mamedov and M. de Llano. Influence of domain walls in the superconductor/ferromagnet proximity effect / E. J. Patino. Spin singlet and triplet superconductivity induced by correlated hopping interactions / L. A. Perez, J. S. Millan and C. Wang -- pt. G. Statistical mechanics, relativistic quantum mechanics. Boltzmann's ergodic hypothesis: A meeting place for two cultures / M. H. Lee. Electron-electron interaction in the non-relativistic limit / F. B. Malik.

  3. Numerical simulation of condensation of sulfuric acid and water in a large two-stroke marine diesel engine

    DEFF Research Database (Denmark)

    Karvounis, Nikolas; Pang, Kar Mun; Mayer, Stefan

    2018-01-01

    In the present study, three-dimensional (3D) computational fluid dynamics simulations are performed to examine the process of sulfuric acid (H2SO4) and water (H2O) condensation in a large two-stroke marine diesel engine. A skeletal n-heptane chemical mechanism is coupled with a sulfur (S) subset...... to simulate the combustion process as well as the formation of sulfuric oxides (SOx) and H2SO4. The condensation process is simulated using a fluid film model which is coupled with the in-cylinder gas phase. Prior to the engine simulations, the fluid film condensation model is validated using the experimental...... data of sulfuric acid condensation rate in a laminar pipe flow. Next, the engine model is validated against the experimental sulfur dioxide (SO2) to sulfur trioxide (SO3) conversion obtained from the corresponding test engine. Both of the validation studies show a good agreement with the experimental...

  4. High temperature Bose-Einstein condensation

    Directory of Open Access Journals (Sweden)

    Begun Viktor

    2016-01-01

    Full Text Available The indications of a possible pion condensation at the LHC are summarized. The condensation is predicted by the non-equilibrium hadronization model for 2.76 TeV Pb+Pb collisions at the LHC. The model solves the proton/pion puzzle and reproduces the low pT enhancement of the pion spectra, as well as the spectra of protons and antiprotons, charged kaons, K0S, K*(8920 and ϕ(1020. The obtained parameters allow to estimate the amount of pion condensate on the level of 5% from the total number of pions at the LHC. The condensate is located at pT < 250 MeV.

  5. Condensate of excitations in moving superfluids

    CERN Document Server

    Kolomeitsev, E E

    2016-01-01

    A possibility of the condensation of excitations with a non-zero momentum in rectilinearly moving and rotating superfluid bosonic and fermionic (with Cooper pairing) media is considered in terms of a phenomenological order-parameter functional at zero and non-zero temperature. The results might be applicable to the description of bosonic systems like superfluid $^4$He, ultracold atomic Bose gases, charged pion and kaon condensates in rotating neutron stars, and various superconducting fermionic systems with pairing, like proton and color-superconducting components in compact stars, metallic superconductors, and neutral fermionic systems with pairing, like the neutron component in compact stars and ultracold atomic Fermi gases. Order parameters of the "mother" condensate in the superfluid and the new condensate of excitations, corresponding energy gains, critical temperatures and critical velocities are found.

  6. Solitons in Bose–Einstein condensates

    Indian Academy of Sciences (India)

    function interaction. Keywords. Solitons .... where Tc is the Bose–Einstein condensation temperature, the bosons are normal so that 〈 〉 vanishes. ... solutions. Small deviations around the background density ρ0 are studied by setting ψ(r, t) = √.

  7. Recent developments in Bose-Einstein condensation

    Energy Technology Data Exchange (ETDEWEB)

    Kalman, G.

    1997-09-22

    This paper contains viewgraphs on developments on Bose-Einstein condensation. Some topics covered are: strongly coupled coulomb systems; standard response functions of the first and second kind; dynamical mean field theory; quasi localized charge approximation; and the main equations.

  8. Light front distribution of the chiral condensate

    National Research Council Canada - National Science Library

    Chang, Lei; Roberts, Craig D; Schmidt, Sebastian M

    2013-01-01

    The pseudoscalar projection of the pionE1/4s Poincare-covariant Bethe-Salpeter amplitude onto the light-front may be understood to provide the probability distribution of the chiral condensate within the pion...

  9. Sensing electric and magnetic fields with Bose-Einstein condensates

    DEFF Research Database (Denmark)

    Wildermuth, Stefan; Hofferberth, S.; Lesanovsky, Igor

    2006-01-01

    We experimentally demonstrate that one-dimensional Bose-Einstein condensates brought close to microfabricated wires on an atom chip are a very sensitive sensor for magnetic and electric fields reaching a sensitivity to potential variations of ∼ 10-14 eV at 3 μm spatial resolution. We measure a two......-dimensional magnetic field map 10 μm above a 100-μm-wide wire and show how the transverse current-density component inside the wire can be reconstructed. The relation between the field sensitivity and the spatial resolution is discussed and further improvements utilizing Feshbach-resonances are outlined....

  10. Condenser Microphone Protective Grid Correction for High Frequency Measurements

    Science.gov (United States)

    Lee, Erik; Bennett, Reginald

    2010-01-01

    Use of a protective grid on small diameter microphones can prolong the lifetime of the unit, but the high frequency effects can complicate data interpretation. Analytical methods have been developed to correct for the grid effect at high frequencies. Specifically, the analysis pertains to quantifying the microphone protective grid response characteristics in the acoustic near field of a rocket plume noise source. A frequency response function computation using two microphones will be explained. Experimental and instrumentation setup details will be provided. The resulting frequency response function for a B&K 4944 condenser microphone protective grid will be presented, along with associated uncertainties

  11. A photointegrator of the molecular condensation nuclei detector

    Directory of Open Access Journals (Sweden)

    Vladimir D. Kuptsov

    2015-06-01

    An experimental study of a photometer of a molecular condensation nuclei (MCN detector that forms a base of highly sensitive MCN gas analyzers was conducted. The measured sensitivity differed from the calculated by 10%. However, at femtowatt power levels it is very difficult to get rid of parasitic optical signals that are responsible for a small decrease in sensitivity compared to the theoretical prediction. In many practical applications, for example, for the X-ray absorption method of mineral extraction using position-sensitive photodiode X- ray receivers, an approximation of a real photointegrator must be used.

  12. Assessment of GOTHIC and TRACE codes against selected PANDA experiments on a Passive Containment Condenser

    Energy Technology Data Exchange (ETDEWEB)

    Papini, Davide, E-mail: davide.papini@psi.ch; Adamsson, Carl; Andreani, Michele; Prasser, Horst-Michael

    2014-10-15

    Highlights: • Code comparison on the performance of a Passive Containment Condenser. • Simulation of separate effect tests with pure steam and non-condensable gases. • Role of the secondary side and accuracy of pool boiling models are discussed. • GOTHIC and TRACE predict the experimental performance with slight underestimation. • Recirculatory flow pattern with injection of light non-condensable gas is inferred. - Abstract: Typical passive safety systems for ALWRs (Advanced Light Water Reactors) rely on the condensation of steam to remove the decay heat from the core or the containment. In the present paper the three-dimensional containment code GOTHIC and the one-dimensional system code TRACE are compared on the calculation of a variety of phenomena characterizing the response of a passive condenser submerged in a boiling pool. The investigation addresses the conditions of interest for the Passive Containment Cooling System (PCCS) proposed for the ESBWR (Economic Simplified Boiling Water Reactor). The analysis of selected separate effect tests carried out on a PCC (Passive Containment Condenser) unit in the PANDA large-scale thermal-hydraulic facility is presented to assess the code predictions. Both pure steam conditions (operating pressure of 3 bar, 6 bar and 9 bar) and the effect on the condensation heat transfer of non-condensable gases heavier than steam (air) and lighter than steam (helium) are considered. The role of the secondary side (pool side) heat transfer on the condenser performance is examined too. In general, this study shows that both the GOTHIC and TRACE codes are able to reasonably predict the heat transfer capability of the PCC as well as the influence of non-condensable gas on the system. A slight underestimation of the condenser performance is obtained with both codes. For those tests where the experimental and simulated efficiencies agree better the possibility of compensating errors among different parts of the heat transfer

  13. Condensate of massive graviton and dark matter

    OpenAIRE

    Aoki, Katsuki; Maeda, Kei-ichi

    2018-01-01

    We study coherently oscillating massive gravitons in the ghost-free bigravity theory. This coherent field can be interpreted as a condensate of the massive gravitons. We first define the effective energy-momentum tensor of the coherent massive gravitons in a curved spacetime. We then study the background dynamics of the universe and the cosmic structure formation including the effects of the coherent massive gravitons. We find that the condensate of the massive graviton behaves as a dark matt...

  14. Stabilization flyuorytopodibnoyi structure in oxide vacuum condensate

    Directory of Open Access Journals (Sweden)

    О.М. Заславський

    2006-01-01

    Full Text Available  The influence of the oxide-stabilizer content, M'-cation radius and film deposition temperature on the stabilization of the fluorite-like solid solutions in the zirconium and hafnium oxides-based vacuum condensates, obtained by Laser-evaporating method, was investigated. The optimum parameters of the coatication of the isotropic thermostable coverings was determined. This results were explained by using of the high-speed condensation in vacuum theory.

  15. Energy condensed packaged systems. Composition, production, properties

    OpenAIRE

    Igor L. Kovalenko; Vitaliy P. Kuprin; Dmytro V. Kiyaschenko

    2015-01-01

    In this paper it is presented the substantiation of choice of fuel phase composition and optimal technology of emulsion production on the basis of binary solution of ammonium and calcium nitrates, which provide the obtaining of energy condensed packaged systems with specified properties. The thermal decomposition of energy condensed systems on the basis of ammonium nitrate is investigated. It is shown that the fuel phase of emulsion systems should be based on esters of polyunsaturated acids o...

  16. Essay: fifty years of condensed matter physics.

    Science.gov (United States)

    Cohen, Marvin L

    2008-12-19

    Since the birth of Physical Review Letters fifty years ago, condensed matter physics has seen considerable growth, and both the journal and the field have flourished during this period. In this essay, I begin with some general comments about condensed matter physics and then give some personal views on the conceptual development of the field and list some highlights. The focus is mostly on theoretical developments.

  17. Numerical simulation of condensation on structured surfaces.

    Science.gov (United States)

    Fu, Xiaowu; Yao, Zhaohui; Hao, Pengfei

    2014-11-25

    Condensation of liquid droplets on solid surfaces happens widely in nature and industrial processes. This phase-change phenomenon has great effect on the performance of some microfluidic devices. On the basis of micro- and nanotechnology, superhydrophobic structured surfaces can be well-fabricated. In this work, the nucleating and growth of droplets on different structured surfaces are investigated numerically. The dynamic behavior of droplets during the condensation is simulated by the multiphase lattice Boltzmann method (LBM), which has the ability to incorporate the microscopic interactions, including fluid-fluid interaction and fluid-surface interaction. The results by the LBM show that, besides the chemical properties of surfaces, the topography of structures on solid surfaces influences the condensation process. For superhydrophobic surfaces, the spacing and height of microridges have significant influence on the nucleation sites. This mechanism provides an effective way for prevention of wetting on surfaces in engineering applications. Moreover, it suggests a way to prevent ice formation on surfaces caused by the condensation of subcooled water. For hydrophilic surfaces, however, microstructures may be submerged by the liquid films adhering to the surfaces. In this case, microstructures will fail to control the condensation process. Our research provides an optimized way for designing surfaces for condensation in engineering systems.

  18. Interstitial Condensation Risk at Thermal Rehabilitated Buildings

    Science.gov (United States)

    Baran, I.; Bliuc, I.; Iacob, A.; Dumitrescu, L.; Pescaru, R. A.; Helepciuc, C.

    2016-11-01

    The increasing thermal insulation degree of existing residential buildings, aiming to reduce the energy requirements for ensuring the indoor comfort, has as expected effect the elimination of condensation risk. However, in some cases this phenomenon occurs, both on the inner surface of the closing element and also in its structure. The surface condensation causes can be identified and can be easily removed. Instead, the causes and even the presence of interstitial condensation are more difficult to be observed. But the moistening of the insulation materials and the reduction of thermal insulation capacity or even its total degradation, contravene into a large extent or totally to the main purpose of the additional thermal protection. To avoid such situations, it is necessary to respect some principles concerning the structure, resulted from the knowledge of the water vapour diffusion behaviour of various materials. It is known that condensation vulnerability is higher for the additional thermal protection solutions by disposing the insulating material on the inside surface of the closing element. But practice has shown that the condensation phenomenon is not totally excluded neither in the case of outside thermal insulation - which is the current solution applied to the rehabilitation works - if the principles mentioned above are not known and respected. In this paper two models are compared on which the risk of interstitial condensation can be checked. The analysis made on two structures of exterior walls with thermal insulation demonstrates the need for additional verifications before proposing a solution for thermal rehabilitation of the envelope elements.

  19. Women Professors of Educational Administration: A Profile and Salient Issues.

    Science.gov (United States)

    Short, Paula M.; And Others

    The purpose of this study is to assess the current status of women professors of educational administration. Research findings are reviewed and discussed in the areas of socialization of women and sex-role stereotyping, mentoring, and networking. A 37-item questionnaire addressed background information, graduate school experiences, first…

  20. [Professor TIAN Cong-huo's experience on clinical acupuncture].

    Science.gov (United States)

    Song, Shi-Yun; Wang, Yin

    2008-10-01

    Professor TIAN's experiences on acupuncture treatment of various difficult diseases with different acupuncture methods based on syndrome differentiation of different patients, for example, para-acupuncture for treatment of migraine, triple puncture at Dazhui (GV 14) for recurrent depression, lifting and thrusting point Shexiaxue for treatment of aphasia, electroacupuncture at Shuigou (GV 26) and Baihui (GV 20) for treatment of schizophrenia, etc. are introduced.

  1. Häbi, professor, teil on Gefilus kapis / Eve Kruuse

    Index Scriptorium Estoniae

    Kruuse, Eve,d1959-

    2008-01-01

    Tartu Ülikooli professor Marika Mikelsaar võitis läinud kuul koos kolleegidega (Tiiu Kullisaar, Epp Songisepp, Hedi Annuk ja Mihkel Zilmer) Soulis ülemaailmse naisleiutajate konkursil ME-3 bakteri avastamise ja probiootikuks arendamise eest kuldmedali

  2. Burnout Syndrome and Self-Efficacy Beliefs in Professors

    Science.gov (United States)

    García Padilla, Arlington Antonio; Escorcia Bonivento, Carla Vanessa; Perez Suarez, Blinis Sat

    The presence of the Burnout syndrome in professors may be regarded as a deterioration of their mental health with negative impacts on their job performance. It is known that teachers develop different activities in the areas of teaching, outreach and research. This study aims to analyze the relationship between the Burnout syndrome and…

  3. Communication professor examines media bias in president's speeches

    OpenAIRE

    Elliott, Jean

    2006-01-01

    Jim A. Kuypers, assistant professor of communication in the College of Liberal Arts and Human Sciences at Virginia Tech, reveals a disturbing world of media bias in his new book Bush's War: Media Bias and Justifications for War in a Terrorist Age (Rowman & Littlefield Publishers, Inc. 2006).

  4. A Comparison of Students' Perceptions of an Ideal Professor.

    Science.gov (United States)

    Gadzella, Bernadette M.; And Others

    A study was done of college students' current perceptions of the most and least important characteristics of an ideal professor. These perceptions were compared with findings from earlier studies, and differences among student groups (based on gender, college status, grade point average (GPA), and majors) were compared. The study surveyed 356…

  5. Analysis of an Instrument on a Quality Professor.

    Science.gov (United States)

    Lytton, Channon R.; Gadzella, Bernadette M.

    The reliability of the questionnaire, Students' Views of an Ideal Professor, was studied. Subjects were 86 students (35 males and 51 females) who were enrolled in psychology classes at a state university. Subjects included 34 freshmen, 27 sophomores, 20 juniors, 4 seniors, and 1 graduate. The questionnaire consists of 25 characteristics of a…

  6. University Professors and Teaching Ethics: Conceptualizations and Expectations

    Science.gov (United States)

    Dean, Kathy Lund; Beggs, Jeri Mullins

    2006-01-01

    After the spectacular ethical breaches in corporate America emerged, business school professors were singled out as having been negligent in teaching ethical standards. This exploratory study asked business school faculty about teaching ethics, including conceptualizations of ethics in a teaching context and opinions of the extent to which…

  7. Tribute to the legend Mr. Veterinary Public Health, Professor James ...

    African Journals Online (AJOL)

    The author was also destined during his Sabbatical Leave to have an interactive interview session with Prof James Steele after attending the 20th Annual James Steele lecture/ 99th birthday Dinner of Professor James Steele 4th and 6th April 2012 at the Texas School of Public Health, Houston, Texas, USA. The interview ...

  8. Postcards from a Road Trip to Innovation: One Professor's Sabbatical

    Science.gov (United States)

    Kelley, Todd R.

    2016-01-01

    Precious moments in life for an educator are taking time to reflect upon his or her teaching practices to evaluate effectiveness and overall impact. Often this reflection is a weekly if not a daily process for educators using a reflective practitioner model (SchÖn, 1983). For professors, many universities have opportunities for tenured faculty to…

  9. Humor and the Emeritus Professor: An Interview with Gene Roth

    Science.gov (United States)

    Vivona, Brian

    2015-01-01

    This essay is a compilation of several conversations with Dr. Gene Roth, Distinguished Teaching Professor Emeritus at Northern Illinois University. Dr. Roth is past President of the Academy of Human Resource Development, and although he is well known for his efforts in bringing humor into the field of HRD, he is not the same Gene Roth that played…

  10. An Examination of Assistant Professors' Project Management Practices

    Science.gov (United States)

    Alpert, Shannon Atkinson; Hartshorne, Richard

    2013-01-01

    Purpose: The purpose of this research was to identify factors that influence the use of project management in higher education research projects by investigating the project management practices of assistant professors. Design/methodology/approach: Using a grounded theory approach that included in-depth, semi-structured interviews with 22…

  11. Developing Student Character: Community College Professors Who Share Power

    Science.gov (United States)

    Humphreys, Connie K.

    2012-01-01

    This phenomenological study examined the definitions, values, and experiences of seven community college professors who have tried to promote student character development by sharing some of their power in the classroom. Power sharing is a participative gesture, and participative teachers can encourage students to become more engaged in their own…

  12. For Professors' Children, the Case for Home Schooling

    Science.gov (United States)

    Pannapacker, W. A.

    2005-01-01

    The number of families who home school their children is growing between five and 15% per year and it is believed that home schoolers outperform their public-educated peers, though critics believe that home schooling is a form of religious fanaticism and a means of avoiding diversity. A professor explains how he and his wife, home school their…

  13. "Women in Science" with Professor Jocelyn Bell Burnell

    Indian Academy of Sciences (India)

    2014-01-11

    January 11, 2014 | 11:30 am | Multimedia hall, New Physical Sciences Building. Chair, WiS panel of the IASc, Prof. Rohini Godbole, IISc will preside. “Women in Science”: an Interactive Discussion. Session with. Prof. Jocelyn Bell Burnell are happy to present. Prof. Dame Jocelyn Bell Burnell is currently a visiting Professor at ...

  14. The professor within the context of African Universities | Nenty ...

    African Journals Online (AJOL)

    It affirms that the professor is the soul of the university which itself is a world-wide liberal space for the development of the human intellect and genius. The paper further argues that when an individual has been able to satisfy the rigours of the professoriate, such an individual owes it as an obligation to impact positively ...

  15. Professor GN Ramachandran's Contributions to X-ray Crystallography

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 6; Issue 10. Professor G. N. Ramachandran's Contributions to X-ray Crystallography. K Venkatesan. General Article Volume 6 Issue 10 October 2001 pp 8-15. Fulltext. Click here to view fulltext PDF. Permanent link:

  16. Ten Things Every Professor Should Know about Assessment

    Science.gov (United States)

    Wolf, Kenneth; Dunlap, Joanna; Stevens, Ellen

    2012-01-01

    This article describes ten key assessment practices for advancing student learning that all professors should be familiar with and strategically incorporate in their classrooms and programs. Each practice or concept is explained with examples and guidance for putting it into practice. The ten are: learning outcomes, performance assessments,…

  17. Professor-Student Rapport Scale: Six Items Predict Student Outcomes

    Science.gov (United States)

    Wilson, Janie H.; Ryan, Rebecca G.

    2013-01-01

    Rapport between students and teachers leads to numerous positive student outcomes, including attitudes toward the teacher and course, student motivation, and perceived learning. The recent development of a Professor-Student Rapport scale offers assessment of this construct. However, a Cronbach's [alpha] of 0.96 indicated item redundancy, and the…

  18. Dilemmas of a Newly Recruited Academic Qualified Professor: A Case

    Science.gov (United States)

    Agrawal, Anand

    2015-01-01

    This case describes the situation of a newly recruited academic professor who volunteered to teach a course on Research Methods to first-term MBA students in a practitioner-oriented case method Business School. Research Methods is a unique course due to its relevance not only in business but also across all graduate programs. Instructional and…

  19. Teaching the College "Nones": Christian Privilege and the Religion Professor

    Science.gov (United States)

    Riswold, Caryn D.

    2015-01-01

    Working with undergraduate students invites teachers into relationship and conversation with young people at a time when they are emerging as adults and forming their identities. Faith is one area of identity formation often attended to by scholars, college professors, and their institutions. But within that, little attention has been paid to…

  20. Identity Issues: Expatriate Professors Teaching and Researching in Qatar

    Science.gov (United States)

    Romanowski, Michael H.; Nasser, Ramzi

    2015-01-01

    Today, academics are more transient, working outside their home countries, than at any other time in the history of academics especially in the Arab World were there is great demand for faculty members educated in Western' culture and academia. However, many of these professors face considerable social, professional and academic challenges in…

  1. Reflections on Finally Becoming a Professor after Forty Years

    Science.gov (United States)

    Watkins, J. Foster

    2016-01-01

    I wrote this reflective piece in 1999 as I was assuming my first full-time position as a professor with limited administrative responsibilities at the University of Alabama at Birmingham (UAB). After 30-plus years in administrative roles in higher education that provided the opportunity to teach on a part-time basis only, I quickly became aware of…

  2. The rotor theories by Professor Joukowsky: Vortex theories

    DEFF Research Database (Denmark)

    Okulov, Valery L.; Sørensen, Jens Nørkær; Wood, David H.

    2015-01-01

    This is the second of two articles with the main, and largely self-explanatory, title "Rotor theories by Professor Joukowsky". This article considers rotors with finite number of blades and is subtitled "Vortex theories". The first article with subtitle "Momentum theories", assessed the starring ...

  3. Kant as a Professor: Some Lessons for Today's Intellectuals ...

    African Journals Online (AJOL)

    The thoughts of every great philosopher is measured and represented by the history of his social background. It is indeed, more appropriate particularly in the case of a great philosopher like Immanuel Kant to single out for special recognition the outstanding characteristics of his early life on his career as a professor of ...

  4. Reflections on the Scholarly Contributions of Professor David H. Jonassen

    Science.gov (United States)

    Reeves, Thomas C.; Lee, Chwee Beng; Hung, Woei

    2013-01-01

    The six papers in this special issue of "Computers and Education" honoring Professor David H. Jonassen are diverse in nature. They also reflect differing interpretations of the implications of Jonassen's work for research and development focused on instructional models and the factors influencing instruction as well as the directions for future…

  5. Championing Inclusion: An Interview with Professor Luanna Meyer

    Science.gov (United States)

    Bevan-Brown, Jill

    2012-01-01

    In May 2012, after a long and impressive career, Luanna Meyer retired from her role as Professor of Education and Director of the Jessie Hetherington Centre for Educational Research at Victoria University. The tributes paid at her retirement ceremony bear testament to a woman who is held in high esteem in the educational community. In this…

  6. On the Seminar of Professor Shulamit Kreitler in MSUPE

    Directory of Open Access Journals (Sweden)

    Fedorova A.I.

    2015-06-01

    Full Text Available From 9 to 15 of February, 2015 in Moscow state university of psychology and education hosted series of seminars of doctor of psychology Shulamit Kreitler. Dr. Kreitler is a professor of Tel-Aviv University, director of psychology studies center in Sheba medical center, Tel-Hashomer, Israel.

  7. On the Seminar of Professor Shulamit Kreitler in MSUPE

    OpenAIRE

    Fedorova A. I.; Scherbakova A.M.

    2015-01-01

    From 9 to 15 of February, 2015 in Moscow state university of psychology and education hosted series of seminars of doctor of psychology Shulamit Kreitler. Dr. Kreitler is a professor of Tel-Aviv University, director of psychology studies center in Sheba medical center, Tel-Hashomer, Israel.

  8. The Effect of Professor's Attractiveness on Distance Learning Students

    Science.gov (United States)

    Liu, Jeanny; Tomasi, Stella D.

    2015-01-01

    Technology enabled learning is becoming more popular and pervasive in education. While the effectiveness of distance learning versus traditional classroom education is strongly debated, human factors such as students' perception of their professors can influence their desire to learn. This research examines the perceptual effect of attractive…

  9. Career Vitality of Professors: A Cognitive Restructuring Model.

    Science.gov (United States)

    Bumpus, J. Frank

    An attributional model that conceptualizes the pressures that reduce professors' personal and career vitality is presented. The model is based primarily on the locus of control literature and especially the reformulated model of learned helplessness by Lynn Abramson, Martin Seligman, and John Teasdale. The analysis deals only with the cognitive…

  10. Could We Talk? Pragmatic Variations in Student-Professor Negotiations.

    Science.gov (United States)

    Biesenbach-Lucas, Sigrun; Weasenforth, Donald

    This study focuses on electronic office hour consultations and investigates the presence and organization of pragmatic elements associated with negotiating the completion and evaluation of coursework in the e-mail messages of 28 American and international students to an American professor. Findings indicate a lack of negotiation skills in the…

  11. Mitotic chromosome condensation in vertebrates

    Energy Technology Data Exchange (ETDEWEB)

    Vagnarelli, Paola, E-mail: P.Vagnarelli@ed.ac.uk

    2012-07-15

    Work from several laboratories over the past 10-15 years has revealed that, within the interphase nucleus, chromosomes are organized into spatially distinct territories [T. Cremer, C. Cremer, Chromosome territories, nuclear architecture and gene regulation in mammalian cells, Nat. Rev. Genet. 2 (2001) 292-301 and T. Cremer, M. Cremer, S. Dietzel, S. Muller, I. Solovei, S. Fakan, Chromosome territories-a functional nuclear landscape, Curr. Opin. Cell Biol. 18 (2006) 307-316]. The overall compaction level and intranuclear location varies as a function of gene density for both entire chromosomes [J.A. Croft, J.M. Bridger, S. Boyle, P. Perry, P. Teague,W.A. Bickmore, Differences in the localization and morphology of chromosomes in the human nucleus, J. Cell Biol. 145 (1999) 1119-1131] and specific chromosomal regions [N.L. Mahy, P.E. Perry, S. Gilchrist, R.A. Baldock, W.A. Bickmore, Spatial organization of active and inactive genes and noncoding DNA within chromosome territories, J. Cell Biol. 157 (2002) 579-589] (Fig. 1A, A'). In prophase, when cyclin B activity reaches a high threshold, chromosome condensation occurs followed by Nuclear Envelope Breakdown (NEB) [1]. At this point vertebrate chromosomes appear as compact structures harboring an attachment point for the spindle microtubules physically recognizable as a primary constriction where the two sister chromatids are held together. The transition from an unshaped interphase chromosome to the highly structured mitotic chromosome (compare Figs. 1A and B) has fascinated researchers for several decades now; however a definite picture of how this process is achieved and regulated is not yet in our hands and it will require more investigation to comprehend the complete process. From a biochemical point of view a vertebrate mitotic chromosomes is composed of DNA, histone proteins (60%) and non-histone proteins (40%) [6]. I will discuss below what is known to date on the contribution of these two different classes

  12. Primes, Geometry and Condensed Matter

    Directory of Open Access Journals (Sweden)

    Al Rabeh R. H.

    2009-07-01

    Full Text Available Fascination with primes dates back to the Greeks and before. Primes are named by some "the elementary particles of arithmetic" as every nonprime integer is made of a unique set of primes. In this article we point to new connections between primes, geometry and physics which show that primes could be called "the elementary particles of physics" too. This study considers the problem of closely packing similar circles/spheres in 2D/3D space. This is in effect a discretization process of space and the allowable number in a pack is found to lead to some unexpected cases of prime configurations which is independent of the size of the constituents. We next suggest that a non-prime can be considered geometrically as a symmetric collection that is separable (factorable into similar parts- six is two threes or three twos for example. A collection that has no such symmetry is a prime. As a result, a physical prime aggregate is more difficult to split symmetrically resulting in an inherent stability. This "number/physical" stability idea applies to bigger collections made from smaller (prime units leading to larger stable prime structures in a limitless scaling up process. The distribution of primes among numbers can be understood better using the packing ideas described here and we further suggest that differing numbers (and values of distinct prime factors making a nonprime collection is an important factor in determining the probability and method of possible and subsequent disintegration. Disintegration is bound by energy conservation and is closely related to symmetry by Noether theorems. Thinking of condensed matter as the packing of identical elements, we examine plots of the masses of chemical elements of the periodic table, and also those of the elementary particles of physics, and show that prime packing rules seem to play a role in the make up of matter. The plots show convincingly that the growth of prime numbers and that of the masses of

  13. Primes, Geometry and Condensed Matter

    Directory of Open Access Journals (Sweden)

    Al Rabeh R. H.

    2009-07-01

    Full Text Available Fascination with primes dates back to the Greeks and before. Primes are named by some “the elementary particles of arithmetic” as every nonprime integer is made of a unique set of primes. In this article we point to new connections between primes, geometry and physics which show that primes could be called “the elementary particles of physics” too. This study considers the problem of closely packing similar circles / spheres in 2D / 3D space. This is in effect a discretization process of space and the allowable num- ber in a pack is found to lead to some unexpected cases of prime configurations which is independent of the size of the constituents. We next suggest that a non-prime can be considered geometrically as a symmetric collection that is separable (factorable into similar parts- six is two threes or three twos for example. A collection that has no such symmetry is a prime. As a result, a physical prime aggregate is more difficult to split symmetrically resulting in an inherent stability. This “number / physical” stability idea applies to bigger collections made from smaller (prime units leading to larger sta- ble prime structures in a limitless scaling up process. The distribution of primes among numbers can be understood better using the packing ideas described here and we further suggest that differing numbers (and values of distinct prime factors making a nonprime collection is an important factor in determining the probability and method of possible and subsequent disintegration. Disintegration is bound by energy conservation and is closely related to symmetry by Noether theorems. Thinking of condensed matter as the packing of identical elements, we examine plots of the masses of chemical elements of the periodic table, and also those of the elementary particles of physics, and show that prime packing rules seem to play a role in the make up of matter. The plots show con- vincingly that the growth of prime numbers and that

  14. Numerical analysis of the influence of circuit arrangement on a fin-and-tube condenser performance

    Directory of Open Access Journals (Sweden)

    Cesare Maria Joppolo

    2015-09-01

    Full Text Available In the present paper a model for the steady-state simulation of fin-and-tube condenser is developed. The model is based on a finite volume approach that divides each tube into small elemental volumes where mass, momentum and energy conservation equations are solved using the effectiveness-NTU method and with appropriate correlations for void fraction, friction factor and heat transfer coefficient calculation. The model is validated against experimental data on two small condensers finding that the calculated heat transfer rate and refrigerant-side pressure drop agree within ±5% and ±21% respectively to the experimental values. The model is then used to numerically analyse the impact of different circuit arrangements on the condenser heat transfer rate, refrigerant-side pressure drop and refrigerant charge.

  15. Role of single-particle and pair condensates in Bose systems with arbitrary intensity of interaction

    Directory of Open Access Journals (Sweden)

    A.S. Peletminskii

    2013-03-01

    Full Text Available We study a superfluid Bose system with single-particle and pair condensates on the basis of a half-phenomenological theory of a Bose liquid not involving the weakness of interparticle interaction. The coupled equations describing the equilibrium state of such system are derived from the variational principle for entropy. These equations are analyzed at zero temperature both analytically and numerically. It is shown that the fraction of particles in the single-particle and pair condensates essentially depends on the total density of the system. At densities attainable in condensates of alkali-metal atoms, almost all particles are in the single-particle condensate. The pair condensate fraction grows with increasing total density and becomes dominant. It is shown that at density of liquid helium, the single-particle condensate fraction is less than 10% that agrees with experimental data on inelastic neutron scattering, Monte Carlo calculations and other theoretical predictions. The ground state energy, pressure, and compressibility are found for the system under consideration. The spectrum of single-particle excitations is also analyzed.

  16. Catalytic ozonation for odour removal of high temperature alumina refinery condensate.

    Science.gov (United States)

    Wang, Xinguang; Guan, Jing; Stuetz, Richard M

    2012-01-01

    Odour emissions from aluminium processing can cause an impact on local communities surrounding such facilities. Of particular concern is fugitive odours emitted from the handling and use of refinery condensate streams, particularly the digestion condensate. This study evaluated the application of using catalytic ozonation to treat alumina refinery condensate in order to remove the potential emission of odourous compounds from the industrial wastewater. The technical challenges in treating the alumina refinery condensate are the high pH and temperatures of the wastewater effluent (over 80 °C and pH above 10) due the industrial process. The odour removal efficiencies for different catalysts (FeCl(3), MnO, and MnSO(4)) under experimental conditions in terms of controlled pH, temperature and ozone dosage were determined before and after ozone treatment using dynamic olfactometry. The result demonstrated that the addition of both FeCl(3) and MnO catalysts improved odour removal efficiencies during the ozonation of alumina condensates at similar pH and temperature conditions. FeCl(3) and MnO had similar enhancement for odour removal, however MnO was determined to be more appropriate than MnSO(4) for odour removal due to the colouration of the treated condensate.

  17. Interfacial Dynamics of Condensing Vapor Bubbles in an Ultrasonic Acoustic Field

    Science.gov (United States)

    Boziuk, Thomas; Smith, Marc; Glezer, Ari

    2016-11-01

    Enhancement of vapor condensation in quiescent subcooled liquid using ultrasonic actuation is investigated experimentally. The vapor bubbles are formed by direct injection from a pressurized steam reservoir through nozzles of varying characteristic diameters, and are advected within an acoustic field of programmable intensity. While kHz-range acoustic actuation typically couples to capillary instability of the vapor-liquid interface, ultrasonic (MHz-range) actuation leads to the formation of a liquid spout that penetrates into the vapor bubble and significantly increases its surface area and therefore condensation rate. Focusing of the ultrasonic beam along the spout leads to ejection of small-scale droplets from that are propelled towards the vapor liquid interface and result in localized acceleration of the condensation. High-speed video of Schlieren images is used to investigate the effects of the ultrasonic actuation on the thermal boundary layer on the liquid side of the vapor-liquid interface and its effect on the condensation rate, and the liquid motion during condensation is investigated using high-magnification PIV measurements. High-speed image processing is used to assess the effect of the actuation on the dynamics and temporal variation in characteristic scale (and condensation rate) of the vapor bubbles.

  18. A path integral formula for quark condensate states in a modified PQCD

    Energy Technology Data Exchange (ETDEWEB)

    Cabo Montes de Oca, A. [Perimeter Institute for Theoretical Physics, Waterloo, Ontario (Canada); Instituto de Cibernetica, Matematica y Fisica, Grupo de Fisica Teorica, La Habana (Cuba); Cabo-Bizet, N.G. [Centro de Aplicaciones Tecnologicas y Desarrollo Nuclear (CEADEN), Departamento de Fisica, La Habana (Cuba); Bonn University, Institute of Physics, Bonn (Germany); Cabo-Bizet, A. [Centro de Aplicaciones Tecnologicas y Desarrollo Nuclear (CEADEN), Departamento de Fisica, La Habana (Cuba)

    2009-11-15

    A modified version of PQCD considered in previous works is investigated here in the case of retaining only the quark condensate. The Green function generating functional is expressed in a form in which Dirac's delta functions are now absent from the free propagators. The new expansion implements the dimensional transmutation effect through a single interaction vertex in addition to the standard ones in massless QCD. The new vertex suggest a way for constructing an alternative to the SM, in which the mass and CKM matrices could be generated by the instability of massless QCD under the production of the top quark and other fermions condensates, in a kind of generalized Nambu-Jona-Lasinio mechanism. The results of a two loop evaluation of the vacuum energy indicate that the quark condensate is dynamically generated. However, the energy as a function of the condensate parameter is again unbounded from below in this approximation. Assuming the existence of a minimum of the vacuum energy at the experimental value of the top quark mass m{sub q} =173 GeV, we evaluate the two particle propagator in the quark-anti-quark channel in zero order in the coupling and a ladder approximation in the condensate vertex. Adopting the notion from the former top quark models in which the Higgs field corresponds to the quark condensate, the results suggest that the Higgs particle could be represented by a meson which might appear at energies around twice the top quark mass. (orig.)

  19. Enhanced tubes for steam condensers. Volume 1, Summary of condensation and fouling; Volume 2, Detailed study of steam condensation

    Energy Technology Data Exchange (ETDEWEB)

    Webb, R.L.; Chamra, L.; Jaber, H.

    1992-02-01

    Electric utility steam condensers typically use plain tubes made of titanium, stainless steel, or copper alloys. Approximately two-thirds of the total thermal resistance is on the water side of the plain tube. This program seeks to conceive and develop a tube geometry that has special enhancement geometries on the tube (water) side and the steam (shell) side. This ``enhanced`` tube geometry, will provide increased heat transfer coefficients. The enhanced tubes will allow the steam to condense at a lower temperature. The reduced condensing temperature will reduce the turbine heat rate, and increase the plant peak load capability. Water side fouling and fouling control is a very important consideration affecting the choice of the tube side enhancement. Hence, we have consciously considered fouling potential in our selection of the tube side surface geometry. Using appropriate correlations and theoretical models, we have designed condensation and water side surface geometries that will provide high performance and be cleanable using sponge ball cleaning. Commercial tube manufacturers have made the required tube geometries for test purposes. The heat transfer test program includes measurement of the condensation and water side heat transfer coefficients. Fouling tests are being run to measure the waterside fouling resistance, and to the test the ability of the sponge ball cleaning system to clean the tubes.

  20. Optical properties of potential condensates in exoplanetary atmospheres

    Science.gov (United States)

    Kitzmann, Daniel; Heng, Kevin

    2018-03-01

    The prevalence of clouds in currently observable exoplanetary atmospheres motivates the compilation and calculation of their optical properties. First, we present a new open-source Mie scattering code known as LX-MIE, which is able to consider large-size parameters (˜107) using a single computational treatment. We validate LX-MIE against the classical MIEVO code as well as previous studies. Secondly, we embark on an expanded survey of the published literature for both the real and imaginary components of the refractive indices of 32 condensate species. As much as possible, we rely on experimental measurements of the refractive indices and resort to obtaining the real from the imaginary component (or vice versa), via the Kramers-Kronig relation, only in the absence of data. We use these refractive indices as input for LX-MIE to compute the absorption, scattering and extinction efficiencies of all 32 condensate species. Finally, we use a three-parameter function to provide convenient fits to the shape of the extinction efficiency curve. We show that the errors associated with these simple fits in the Wide Field Camera 3 (WFC3), J, H, and K wavebands are ˜ 10 per cent. These fits allow for the extinction cross-section or opacity of the condensate species to be easily included in retrieval analyses of transmission spectra. We discuss prospects for future experimental work. The compilation of the optical constants and LX-MIE is publicly available as part of the open-source Exoclime Simulation Platform (http://www.exoclime.org).

  1. Refletindo sobre a relação professor-aluno em um grupo de professores do Esino Fundamental

    Directory of Open Access Journals (Sweden)

    Antônio dos Santos Andrade

    1999-06-01

    Full Text Available A partir das concepções de Donald Schön sobre a formação do professor como prático reflexivo, os princípios de trabalho com pequenos grupos, baseados nas concepções de J. L Moreno, foram utilizados com o objetivo de facilitar o processo de reflexão sobre suas práticas de sala de aula, com seis professores do Ensino Fundamental. Foram realizados nove encontros de 90 a 120 minutos de duração. Nas discussões, os casos dos alunos mais problemáticos quanto ao seu comportamento foram trazidos pelos professores e analisados pelo grupo a luz das concepções da Pragmática da Comunicação Humana. Como resultado destas discussões, os professores foram levados a considerar os aspectos mais latentes, e portanto significantes, de suas relações com os alunos. Estas reflexões conduziram a uma "resignificação" das mesmas, com efeitos surpreendentes sobre os comportamentos dos alunos.

  2. Why Did the Professor Cross the Road? How and Why College Professors Intentionally Use Humor in Their Teaching

    Science.gov (United States)

    Buckman, Karen Hildebrant

    2010-01-01

    College professors face many pressing challenges: staying current in their disciplines, becoming familiar with new technology, responding to national accountability issues, publishing scholarly research in their fields, and facilitating student learning in their classes. Teaching and learning are complex processes. Humor is a powerful…

  3. Yue Joseph Wang named Grant A. Dove Professor of Electrical and Computer Engineering

    OpenAIRE

    Owczarski, Mark

    2009-01-01

    Yue Joseph Wang, professor of electrical and computer engineering in the College of Engineering at Virginia Tech, has been named the Grant A. Dove Professor of Electrical and Computer Engineering by the Virginia Tech Board of Visitors.

  4. Maury Nussbaum reappointed as Hal G. Prillaman Professor Fellow in Industrial and Systems Engineering

    OpenAIRE

    Owczarski, Mark

    2010-01-01

    Maury Nussbaum, professor of industrial and systems engineering in the College of Engineering at Virginia Tech, has been reappointed as the Hal G. Prillaman Professor Fellow in Industrial and Systems Engineering by the Virginia Tech Board of Visitors.

  5. Brian M. Kleiner receives Ralph H. Bogle Professor Fellowship in Industrial and Systems Engineering

    OpenAIRE

    Owczarski, Mark

    2010-01-01

    Brian M. Kleiner, professor of industrial and systems engineering in the College of Engineering at Virginia Tech, has been named the Ralph H. Bogle Professor Fellow in Industrial and Systems Engineering by the Virginia Tech Board of Visitors.

  6. GENOTOXICITY OF TEN CIGARETTE SMOKE CONDENSATES IN FOUR TEST SYSTEMS: COMPARISONS BETWEEN ASSAYS AND CONDENSATES

    Science.gov (United States)

    What is the study? This the first assessment of a set of cigarette smoke condensates from a range of cigarette types in a variety (4) of short-term genotoxicity assays. Why was it done? No such comparative study of cigarette smoke condensates has been reported. H...

  7. Quantum tunneling of Bose-Einstein condensates in optical lattices

    CERN Document Server

    Fan Wen Bin

    2003-01-01

    In quantum tunneling a particle with energy E can pass through a high potential barrier V(>E) due to the wave character of the particle. Bose-Einstein condensates can display very strong tunneling depending on the structure of the trap, which may be a double-well or optical lattices. The employed for the first time to our knowledge the periodic instanton method to investigate tunneling of Bose-Einstein condensates in optical lattices. The results show that there are two kinds of tunneling in this system, Landau-Zener tunneling between extended states of the system and Wannier-Stark tunneling between localized states of the system, and that the latter is 1000 times faster than the former. The also obtain the total decay rate for a wide range of temperature, including classical thermal activation, thermally assisted tunneling and quantum tunneling. The results agree with experimental data in references. Finally, the propose an experimental protocol to observe this new phenomenon in future experiments

  8. Improvement of wall condensation modeling with suction wall functions for containment application

    Energy Technology Data Exchange (ETDEWEB)

    Lehmkuhl, Jan, E-mail: j.lehmkuhl@fz-juelich.de [RWTH Aachen University, Aachen (Germany); Kelm, Stephan, E-mail: s.kelm@fz-juelich.de [Forschungszentrum Jülich GmbH, Jülich (Germany); Bucci, Matteo [Commissariat à l’énergie atomique et aux énergies alternatives, Paris (France); Allelein, Hans-Josef [RWTH Aachen University, Aachen (Germany); Forschungszentrum Jülich GmbH, Jülich (Germany)

    2016-04-01

    Highlights: • Assessment of wall functions for single phase condensation models for large scale application. • Identification of modeling errors related to standard log-law due to buoyancy and wall normal mass transfer (suction). • Modeling of wall normal mass transfer by literature formulation (Sucec, 1999) and in-house approach (FIBULA). • Validation against isothermal Favre experimental data. • Comparison against reference fine grid solution for condensing conditions. - Abstract: To simulate wall condensation on containment scale with CFD methods at reasonable computational cost, a single phase approach has to be applied and wall functions have to be used. However, standard wall functions were derived for flows without heat and mass transfer and their fundamental simplifications are not appropriate to deal with condensation. This paper discusses the limitations of standard wall functions and proposes two wall functions for the momentum equation dealing with mass transfer normal to the sheared wall (suction). The first proposed suction wall function is an algebraic modification based on the standard wall function concept. The second proposed wall function is an in-house developed suction wall function with the potential to cover also heat and mass transfer effects by storing the complex solutions of the RANS-Equations in a lookup table. The wall function approaches are compared to experimental results for boundary layer flows with suction and to the reference results obtained using a refined grid in order to resolve the condensing boundary layer.

  9. Why double-stranded RNA resists condensation

    Science.gov (United States)

    Tolokh, Igor S.; Pabit, Suzette A.; Katz, Andrea M.; Chen, Yujie; Drozdetski, Aleksander; Baker, Nathan; Pollack, Lois; Onufriev, Alexey V.

    2014-01-01

    The addition of small amounts of multivalent cations to solutions containing double-stranded DNA leads to inter-DNA attraction and eventual condensation. Surprisingly, the condensation is suppressed in double-stranded RNA, which carries the same negative charge as DNA, but assumes a different double helical form. Here, we combine experiment and atomistic simulations to propose a mechanism that explains the variations in condensation of short (25 base-pairs) nucleic acid (NA) duplexes, from B-like form of homopolymeric DNA, to mixed sequence DNA, to DNA:RNA hybrid, to A-like RNA. Circular dichroism measurements suggest that duplex helical geometry is not the fundamental property that ultimately determines the observed differences in condensation. Instead, these differences are governed by the spatial variation of cobalt hexammine (CoHex) binding to NA. There are two major NA-CoHex binding modes—internal and external—distinguished by the proximity of bound CoHex to the helical axis. We find a significant difference, up to 5-fold, in the fraction of ions bound to the external surfaces of the different NA constructs studied. NA condensation propensity is determined by the fraction of CoHex ions in the external binding mode. PMID:25123663

  10. Increasing the efficiency of the condensing boiler

    Science.gov (United States)

    Zaytsev, ON; Lapina, EA

    2017-11-01

    Analysis of existing designs of boilers with low power consumption showed that the low efficiency of the latter is due to the fact that they work in most cases when the heating period in the power range is significantly less than the nominal power. At the same time, condensing boilers do not work in the most optimal mode (in condensing mode) in the central part of Russia, a significant part of their total operating time during the heating season. This is due to existing methods of equipment selection and joint operation with heating systems with quantitative control of the coolant. It was also revealed that for the efficient operation of the heating system, it is necessary to reduce the inertia of the heat generating equipment. Theoretical patterns of thermal processes in the furnace during combustion gas at different radiating surfaces location schemes considering the influence of the very furnace configuration, characterized in that to reduce the work condensing boiler in conventional gas boiler operation is necessary to maintain a higher temperature in the furnace (in the part where spiral heat exchangers are disposed), which is possible when redistributing heat flow - increase the proportion of radiant heat from the secondary burner emitter allow Perey For the operation of the condensing boiler in the design (condensation) mode practically the entire heating period.

  11. Energy condensed packaged systems. Composition, production, properties

    Directory of Open Access Journals (Sweden)

    Igor L. Kovalenko

    2015-03-01

    Full Text Available In this paper it is presented the substantiation of choice of fuel phase composition and optimal technology of emulsion production on the basis of binary solution of ammonium and calcium nitrates, which provide the obtaining of energy condensed packaged systems with specified properties. The thermal decomposition of energy condensed systems on the basis of ammonium nitrate is investigated. It is shown that the fuel phase of emulsion systems should be based on esters of polyunsaturated acids or on combinations thereof with petroleum products. And ceresin or petroleum wax can be used as the structuring additive. The influence of the technology of energy condensed systems production on the physicochemical and detonation parameters of emulsion explosives is considered. It is shown the possibility of obtaining of emulsion systems with dispersion of 1.3...1.8 microns and viscosity higher than 103 Pa∙s in the apparatus of original design. The sensitizing effect of chlorinated paraffin CP-470 on the thermolysis of energy condensed emulsion system is shown. The composition and production technology of energy condensed packaged emulsion systems of mark Ukrainit-P for underground mining in mines not dangerous on gas and dust are developed.

  12. Structure of vacuum Cu-Ta condensates

    Science.gov (United States)

    Zubkov, A. I.; Zubarev, E. N.; Sobol', O. V.; Hlushchenko, M. A.; Lutsenko, E. V.

    2017-02-01

    The structure of vacuum condensate foils (separated from substrates) of the binary Cu-Ta system has been investigated both in the initial condensed state and after annealings at temperatures of up to 1000°C. It has been shown that the alloying of a vapor flow of the matrix metal (copper) with tantalum to 0.5 at % makes it possible to reduce the grain size from 3 μm to 50 nm. Depending on the tantalum concentration, condensates exhibit a broad spectrum of structural states, i.e., single- and two-phase, a supersaturated solution of tantalum in the fcc lattice of copper, etc. The structure of the objects possesses a high thermal stability. The temperature of the start of grain growth in the copper matrix depends on the tantalum content and can reach 900°C. The dispersion of the structure of copper condensates and its thermal stability is due to the formation of segregates of tantalum atoms at the boundaries of grains of the copper matrix both in the process of condensation and upon subsequent annealing.

  13. Heat transfer, condensation and fog formation in crossflow plastic heat exchangers

    NARCIS (Netherlands)

    Brouwers, Jos; van der Geld, C.W.M.

    1996-01-01

    In this paper heat transfer of air-water-vapour mixtures in plastic crossflow heat exchangers is studied theoretically and experimentally. First, a model for heat transfer without condensation is derived, resulting in a set of classical differential equations. Subsequently, heat transfer with wall

  14. Towards a microscopic description of an alpha-condensate in nuclei

    CERN Document Server

    Delion, D S; Liotta, R J

    2002-01-01

    A theory to describe alpha condensates in nuclei is presented. The corresponding quasiparticles consist of fermions as well as bosons. The fermions are a combination of one- particle and three-hole states, while the bosons are combinations of pair-particles and pair-holes. A relation between the fermionic and bosonic gap parameters is predicted and confirmed by experimental data. (authors)

  15. The Zinc Mediated Condensation of Amino Acid Esters with Imines to b-Lactams

    NARCIS (Netherlands)

    Koten, G. van; Jastrzebski, J.T.B.H.

    1993-01-01

    An experimentally attractive stereoselectie 'one pot' synthesis of beta-lactams is described. This route is based on the zinc mediated condensation of an alpha-amino acid ester with an imine via a zinc ester enolate. Making use of proper substituents in both the amino acid ester and the imine the

  16. The Association of Professors' Style, Trait Anxiety, and Experience with Students' Grades.

    Science.gov (United States)

    Theodory, George C.; Day, Richard C.

    1985-01-01

    The relationship between the style, trait anxiety, and experience of professors and students' grades was investigated using Fiedler's contingency theory. Results indicated professors' trait anxiety is significant influencing student grades; professors having a high Least Preferred co-worker score assigned grades negatively correlated related with…

  17. Professors and Coaches Educational Approaches That Support the NCAA Division III Student Athlete Experience

    Science.gov (United States)

    Kuntz, Daniel E.

    2011-01-01

    While professors and coaches have the ability to enable or impede student athletes' educational success in college, studies that address the perspectives of coaches and professors about their interactions with student athletes are limited. This study aimed to understand (a) the ways in which professors and coaches who act as institutional agents…

  18. A Mixed Analysis of College Students' Best and Poorest College Professors

    Science.gov (United States)

    Slate, John R.; LaPrairie, Kimberly; Schulte, Don P.; Onwuegbuzie, Anthony J.

    2009-01-01

    In this study, the authors examined the views of 171 college students concerning their best and poorest college professors. In a multi-stage conversion mixed analysis design, students' stories of their best and poorest college professors were thematically analysed, resulting in 15 dominant themes for their best college professors and 12 dominant…

  19. A Changing Role for University Professors? Professorial Academic Leadership as It Is Perceived by "The Led"

    Science.gov (United States)

    Evans, Linda

    2015-01-01

    This article examines the academic leadership role of university professors in the UK (a grade title which in that national context generally refers only to the most distinguished, senior academics, who equate to the North American full professor). Drawing on theoretical interpretations of professionalism and applying these to professors, it…

  20. PREFACE: Special section on Computational Fluid Dynamics—in memory of Professor Kunio Kuwahara Special section on Computational Fluid Dynamics—in memory of Professor Kunio Kuwahara

    Science.gov (United States)

    Ishii, Katsuya

    2011-08-01

    This issue includes a special section on computational fluid dynamics (CFD) in memory of the late Professor Kunio Kuwahara, who passed away on 15 September 2008, at the age of 66. In this special section, five articles are included that are based on the lectures and discussions at `The 7th International Nobeyama Workshop on CFD: To the Memory of Professor Kuwahara' held in Tokyo on 23 and 24 September 2009. Professor Kuwahara started his research in fluid dynamics under Professor Imai at the University of Tokyo. His first paper was published in 1969 with the title 'Steady Viscous Flow within Circular Boundary', with Professor Imai. In this paper, he combined theoretical and numerical methods in fluid dynamics. Since that time, he made significant and seminal contributions to computational fluid dynamics. He undertook pioneering numerical studies on the vortex method in 1970s. From then to the early nineties, he developed numerical analyses on a variety of three-dimensional unsteady phenomena of incompressible and compressible fluid flows and/or complex fluid flows using his own supercomputers with academic and industrial co-workers and members of his private research institute, ICFD in Tokyo. In addition, a number of senior and young researchers of fluid mechanics around the world were invited to ICFD and the Nobeyama workshops, which were held near his villa, and they intensively discussed new frontier problems of fluid physics and fluid engineering at Professor Kuwahara's kind hospitality. At the memorial Nobeyama workshop held in 2009, 24 overseas speakers presented their papers, including the talks of Dr J P Boris (Naval Research Laboratory), Dr E S Oran (Naval Research Laboratory), Professor Z J Wang (Iowa State University), Dr M Meinke (RWTH Aachen), Professor K Ghia (University of Cincinnati), Professor U Ghia (University of Cincinnati), Professor F Hussain (University of Houston), Professor M Farge (École Normale Superieure), Professor J Y Yong (National

  1. Spin-Tensor-Momentum-Coupled Bose-Einstein Condensates

    Science.gov (United States)

    Luo, Xi-Wang; Sun, Kuei; Zhang, Chuanwei

    2017-11-01

    The recent experimental realization of spin-orbit coupling for ultracold atomic gases provides a powerful platform for exploring many interesting quantum phenomena. In these studies, spin represents the spin vector (spin 1 /2 or spin 1) and orbit represents the linear momentum. Here we propose a scheme to realize a new type of spin-tensor-momentum coupling (STMC) in spin-1 ultracold atomic gases. We study the ground state properties of interacting Bose-Einstein condensates with STMC and find interesting new types of stripe superfluid phases and multicritical points for phase transitions. Furthermore, STMC makes it possible to study quantum states with dynamical stripe orders that display density modulation with a long tunable period and high visibility, paving the way for the direct experimental observation of a new dynamical supersolidlike state. Our scheme for generating STMC can be generalized to other systems and may open the door for exploring novel quantum physics and device applications.

  2. Cytotoxicity of eight cigarette smoke condensates in three test systems: comparisons between assays and condensates.

    Science.gov (United States)

    Richter, Patricia A; Li, Albert P; Polzin, Gregory; Roy, Shambhu K

    2010-12-01

    Cytotoxic properties of tobacco smoke are associated with chronic tobacco-related diseases. The cytotoxicity of tobacco smoke can be tested with short-term predictive assays. In this study, we compare eight mainstream cigarette smoke condensates (CSCs) from commercial and experimental cigarettes in three different cytotoxicity assays with unique and overlapping endpoints. The CSCs demonstrated cytotoxicity in all assays. In the multiple cytotoxicity endpoint (MCE) assay with TK-6 cells, the cigarette varieties that had the highest EC50s for reduced cell growth also showed a positive dose-response relationship for necrotic cells. In the IdMOC multiple cell-type co-culture (MCTCC) system, all CSCs reduced the viability of the cells. Low concentrations of some CSCs had a stimulatory effect in lung microvascular endothelial cells and small airway epithelial cells. In the neutral dye assay (NDA), except for a 100% flue-cured tobacco CSC, there was little consistency between CSCs producing morphological evidence of moderate or greater toxicity and the CSCs with the lowest EC50s in the MCE or MCTCC assays. Overall, cigarettes made with flue-cured tobacco were the most cytotoxic across the assays. When results were expressed on a per-mg of nicotine basis, lower tar cigarettes were the most cytotoxic in primary human respiratory cells. Published by Elsevier Inc.

  3. Field theories of condensed matter physics

    CERN Document Server

    Fradkin, Eduardo

    2013-01-01

    Presenting the physics of the most challenging problems in condensed matter using the conceptual framework of quantum field theory, this book is of great interest to physicists in condensed matter and high energy and string theorists, as well as mathematicians. Revised and updated, this second edition features new chapters on the renormalization group, the Luttinger liquid, gauge theory, topological fluids, topological insulators and quantum entanglement. The book begins with the basic concepts and tools, developing them gradually to bring readers to the issues currently faced at the frontiers of research, such as topological phases of matter, quantum and classical critical phenomena, quantum Hall effects and superconductors. Other topics covered include one-dimensional strongly correlated systems, quantum ordered and disordered phases, topological structures in condensed matter and in field theory and fractional statistics.

  4. Orientifold Planar Equivalence: The Chiral Condensate

    DEFF Research Database (Denmark)

    Armoni, Adi; Lucini, Biagio; Patella, Agostino

    2008-01-01

    in SU($N$) Yang-Mills in the large $N$ limit. Then, we compute numerically those quenched condensates for $N$ up to 8. After separating the even from the odd corrections in $1/N$, we are able to show that our data support the equivalence; however, unlike other quenched observables, subleading terms......The recently introduced orientifold planar equivalence is a promising tool for solving non-perturbative problems in QCD. One of the predictions of orientifold planar equivalence is that the chiral condensates of a theory with $N_f$ flavours of Dirac fermions in the symmetric (or antisymmetric......) representation and $N_f$ flavours of Majorana fermions in the adjoint representation have the same large $N$ value for any value of the mass of the (degenerate) fermions. Assuming the invariance of the theory under charge conjugation, we prove this statement on the lattice for staggered quenched condensates...

  5. Preoperational test report, recirculation condenser cooling systems

    Energy Technology Data Exchange (ETDEWEB)

    Clifton, F.T.

    1997-11-04

    This represents a preoperational test report for Recirculation Condenser Systems, Project W-030. Project W-030 provides a ventilation upgrade for the four Aging Waste Facility tanks. The four system provide condenser cooling water for vapor space cooling of tanks AY1O1, AY102, AZ1O1, AZ102. Each system consists of a valved piping loop, a pair of redundant recirculation pumps, a closed-loop evaporative cooling tower, and supporting instrumentation; equipment is located outside the farm on concrete slabs. Piping is routed to the each ventilation condenser inside the farm via below-grade concrete trenches. The tests verify correct system operation and correct indications displayed by the central Monitor and Control System.

  6. Dropwise condensation on inclined textured surfaces

    CERN Document Server

    Khandekar, Sameer

    2014-01-01

    Dropwise Condensation on Textured Surfaces presents a holistic framework for understanding dropwise condensation through mathematical modeling and meaningful experiments. The book presents a review of the subject required to build up models as well as to design experiments. Emphasis is placed on the effect of physical and chemical texturing and their effect on the bulk transport phenomena. Application of the model to metal vapor condensation is of special interest. The unique behavior of liquid metals, with their low Prandtl number and high surface tension, is also discussed. The model predicts instantaneous drop size distribution for a given level of substrate subcooling and derives local as well as spatio-temporally averaged heat transfer rates and wall shear stress.

  7. DROPWISE CONDENSATION ON MICRO- AND NANOSTRUCTURED SURFACES

    Energy Technology Data Exchange (ETDEWEB)

    Enright, R; Miljkovic, N; Alvarado, JL; Kim, K; Rose, JW

    2014-07-23

    In this review we cover recent developments in the area of surface-enhanced dropwise condensation against the background of earlier work. The development of fabrication techniques to create surface structures at the micro-and nanoscale using both bottom-up and top-down approaches has led to increased study of complex interfacial phenomena. In the heat transfer community, researchers have been extensively exploring the use of advanced surface structuring techniques to enhance phase-change heat transfer processes. In particular, the field of vapor-to-liquid condensation and especially that of water condensation has experienced a renaissance due to the promise of further optimizing this process at the micro-and nanoscale by exploiting advances in surface engineering developed over the last several decades.

  8. Fermion masses through four-fermion condensates

    CERN Document Server

    Ayyar, Venkitesh

    2016-01-01

    Fermion masses can be generated through four-fermion condensates when symmetries prevent fermion bilinear condensates from forming. This less explored mechanism of fermion mass generation is responsible for making four reduced staggered lattice fermions massive at strong couplings in a lattice model with a local four-fermion coupling. The model has a massless fermion phase at weak couplings and a massive fermion phase at strong couplings. In particular there is no spontaneous symmetry breaking of any lattice symmetries in both these phases. Recently it was discovered that in three space-time dimensions there is a direct second order phase transition between the two phases. Here we study the same model in four space-time dimensions and find results consistent with the existence of a narrow intermediate phase with fermion bilinear condensates, that separates the two asymptotic phases by continuous phase transitions.

  9. Temporal dynamics of Bose-condensed gases

    Energy Technology Data Exchange (ETDEWEB)

    Trujillo Martinez, Mauricio

    2014-03-19

    We perform a detailed quantum dynamical study of non-equilibrium trapped, interacting Bose-condensed gases. We investigate Josephson oscillations between interacting Bose-Einstein condensates confined in a finite size double-well trap and the non-trivial time evolution of a coherent state placed at the center of a two dimensional optical lattice. For the Josephson oscillations three time scales appear. We find that Josephson junction can sustain multiple undamped oscillations up to a characteristic time scale τ{sub c} without exciting atoms out of the condensates. Beyond the characteristic time scale τ{sub c} the dynamics of the junction are governed by fast, non-condensed particles assisted Josephson tunnelling as well as the collisions between non-condensed particles. In the non-condensed particles dominated regime we observe strong damping of the oscillations due to inelastic collisions, equilibrating the system leading to an effective loss of details of the initial conditions. In addition, we predict that an initially self-trapped BEC state will be destroyed by these fast dynamics. The time evolution of a coherent state released at the center of a two dimensional optical lattice shows a ballistic expansion with a decreasing expansion velocity for increasing two-body interactions strength and particle number. Additionally, we predict that if the two-body interactions strength exceeds a certain value, a forerunner splits up from the expanding coherent state. We also observe that this system, which is prepared far from equilibrium, can evolve to a quasistationary non-equilibrium state.

  10. An Outstanding Career: Professor Emeritus Iacob Cătoiu

    Directory of Open Access Journals (Sweden)

    Octavian Oprică

    2016-05-01

    Full Text Available Through the duration of his commissions of Deputy Dean (1981-1989 and, respectively, Dean (1992-2003, and also by the manner of approaching the managerial problems and his scientific extension, Professor Iacob Cătoiu left and indelible trace on the evolution of the former Department of Commerce in the Bucharest University of Economic Studies (ASE – now the Department of Business and Tourism. He is author or co-author of an important number of books (57 and articles (105 and book presentations. Thus, after he made the personal acquaintance with Philip Kotler, the guru of international marketing, in 1997, Professor Iacob Cătoiu wrote the Forward to the Romanian version of Philip Kotler's volume Managementul marketingului (Marketing Management a fundamental book in its field. (Nicolae Lupu

  11. PHYSICAL ACTIVITY AND EATING HABITS IN UNIVERSITY PROFESSORS: LITERATURE REVIEW

    Directory of Open Access Journals (Sweden)

    Hector Luiz Rodrigues Munaro

    2015-01-01

    Full Text Available Increasingly, university professors engage in academic tasks often stressful and sedentary behaviors, making the practice of physical activity and healthier eating habits. The aim of this study was to review the literature Brazilian studies on physical activity and eating habits of university professors .The search was conducted between March and May 2013, in electronic databases. For the delimitation of the study, was used as descriptors: Physical Activity, University Teachers and Eating Habits. At the end of the article selection process, remaining 06 studies that have been described and discussed in the text. And all of a descriptive nature, with small samples with some robust and consistent methodology. The selected studies, regardless of their qualities, point to the need of this population to engage in more physical activity and healthy eating habits programs

  12. The University Professor View from the Communitarian Perspective

    Directory of Open Access Journals (Sweden)

    Angela Del Valle López

    2014-04-01

    Full Text Available The task of the university professor is a mission and not simply a profession and that is why higher education should be impregnated with values. Nowadays education is articulated into three areas: the State, the Market and the Volunteering, but no one of these three sectors by themselves has covered the needs of all the citizens, there have always been losers, therefore the conjunction of the three sectors became necessary. Communitarianism promotes an ethical-social pact that favors the progress of society without nullifying the individual dimension. It believes that the university is the space where a communitarian consciousness should be promoted to generate a social capital by means of education and it is a privilege place to substantiate the moral identity of the person beginning with the commitment of the professor with the university student.

  13. PHYSICAL ACTIVITY AND EATING HABITS IN UNIVERSITY PROFESSORS: LITERATURE REVIEW

    Directory of Open Access Journals (Sweden)

    Hector Luiz Rodrigues Munaro

    2015-03-01

    Full Text Available Increasingly, university professors engage in academic tasks often stressful and sedentary behaviors, making the practice of physical activity and healthier eating habits. The aim of this study was to review the literature Brazilian studies on physical activity and eating habits of university professors .The search was conducted between March and May 2013, in electronic databases. For the delimitation of the study, was used as descriptors: Physical Activity, University Teachers and Eating Habits. At the end of the article selection process, remaining 06 studies that have been described and discussed in the text. And all of a descriptive nature, with small samples with some robust and consistent methodology. The selected studies, regardless of their qualities, point to the need of this population to engage in more physical activity and healthy eating habits programs.

  14. [The professor-student relationship in coping with dying].

    Science.gov (United States)

    Pinho, Líũcia Maria Oliveira; Barbosa, Maria Alves

    2010-03-01

    The new guidelines for undergraduate courses in the field of health care imply a need to prepare professionals to deal with life and death. To study death and dying in the context of nurse education means to contribute to the humanization of education and to preparing humanistic and critical professionals. We performed individual interviews with professors so that each could reveal their thoughts about experiencing death and dying in the educational relationship between nurse/professor and the nursing student in the hospital environment. Content analysis was performed using ideas close to those of Heidegger, revealing that education towards the concept and experience of death appears to be possible only if there is reflection regarding human existence, thoughts, and accepting finitude. By understanding one's own attitudes towards death and existence, it is possible to perceive possibilities in education for care in the death process.

  15. The university professor: integration between the personal and professional dimension

    Directory of Open Access Journals (Sweden)

    José Javier BERMÚDEZ-APONTE

    2017-12-01

    Full Text Available In the first part of this article, the authors explain how the teaching role is affected by certain social and cultural changes, like the knowledge society emergence, the universities orientation towards marketing, the constant demand and pressure exerted on teachers to publish, the loss of the ethical sense in the academic activity and the disparity of tasks that are being assigned to the university professors. In view of the above, a comprehensive model, compound by two concepts –personal and professional– of a university professor is proposed; in fact, this model incorporates and summarises different contributions regarding this theme. Finally, this article aims to defend the need to understand the teaching role as a vocation, in the broadest sense of the word, a vocation carries the inclination to pursue an aim: the education of those students that teachers have in charge.

  16. Novel insights into mitotic chromosome condensation

    Science.gov (United States)

    Piskadlo, Ewa; Oliveira, Raquel A.

    2016-01-01

    The fidelity of mitosis is essential for life, and successful completion of this process relies on drastic changes in chromosome organization at the onset of nuclear division. The mechanisms that govern chromosome compaction at every cell division cycle are still far from full comprehension, yet recent studies provide novel insights into this problem, challenging classical views on mitotic chromosome assembly. Here, we briefly introduce various models for chromosome assembly and known factors involved in the condensation process (e.g. condensin complexes and topoisomerase II). We will then focus on a few selected studies that have recently brought novel insights into the mysterious way chromosomes are condensed during nuclear division. PMID:27508072

  17. Nonlocal Condensate Model for QCD Sum Rules

    OpenAIRE

    Hsieh, Ron-Chou; Li, Hsiang-nan

    2009-01-01

    We include effects of nonlocal quark condensates into QCD sum rules (QSR) via the K$\\ddot{\\mathrm{a}}$ll$\\acute{\\mathrm{e}}$n-Lehmann representation for a dressed fermion propagator, in which a negative spectral density function manifests their nonperturbative nature. Applying our formalism to the pion form factor as an example, QSR results are in good agreement with data for momentum transfer squared up to $Q^2 \\approx 10 $ GeV$^2$. It is observed that the nonlocal quark condensate contribut...

  18. Chiral Lagrangians and quark condensate in nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Delorme, J.; Chanfray, G.; Ericson, M.

    1996-03-01

    The evolution of density of quark condensate in nuclear medium with interacting nucleons, including the short range correlations is examined. Two chiral models are used, the linear sigma model and the non-linear one. It is shown that the quark condensate, as other observables, is independent on the variant selected. The application to physical pions excludes the linear sigma model as a credible one. The non-linear models restricted to pure s-wave pion-nucleon scattering are examined. (author). 28 refs.; Submitted to nuclear Physics, A (NL).

  19. Formation Time of a Fermion Pair Condensate

    OpenAIRE

    Zwierlein, M. W.; Schunck, C. H.; Stan, C. A.; Raupach, S. M. F.; Ketterle, W.

    2004-01-01

    The formation time of a condensate of fermionic atom pairs close to a Feshbach resonance was studied. This was done using a phase-shift method in which the delayed response of the many-body system to a modulation of the interaction strength was recorded. The observable was the fraction of condensed molecules in the cloud after a rapid magnetic field ramp across the Feshbach resonance. The measured response time was slow compared to the rapid ramp, which provides final proof that the molecular...

  20. Analytical Treatment of Normal Condensation Shock

    Science.gov (United States)

    Heybey

    1947-01-01

    The condensation of water vapor in an air consequences: acquisition of heat (liberated heat vaporization; loss of mass on the part of the flowing gas (water vapor is converted to liquid); change in the specific gas constants and of the ratio k of the specific heats (caused by change of gas composition). A discontinuous change of state is therefore connected with the condensation; schlieren photographs of supersonic flows in two-dimensional Laval nozzles show two intersecting oblique shock fronts that in the case of high humidities may merge near the point of intersection into one normal shock front.