Note: This page contains sample records for the topic thermosyphon effect from Science.gov.
While these samples are representative of the content of Science.gov,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of Science.gov
to obtain the most current and comprehensive results.
Last update: November 12, 2013.
1

Effects of Bond Numbers on Internal Flow Patterns of AN Inclined, Closed, Two-Phase Thermosyphon at Normal Operating Conditions  

Microsoft Academic Search

A visual study of internal flow patterns inside an inclined, closed, two-phase thermosyphon at normal operating conditions for several Bond numbers has been conducted. This article describes the effects of varying inclination angles and Bond numbers (Bo) onflow patterns, A copper thermosyphon was used. R123 was selected as the working fluid, with a vapor temperature of 30°C and a filling

P. Terdtoon; M. Chailungkar; S. Ritthidej; M. Shiraishi

1997-01-01

2

Effect of nanoparticles in nanofluid on thermal performance in a miniature thermosyphon  

NASA Astrophysics Data System (ADS)

An experiment was performed to investigate the effect of nanoparticles in the nanofluid on the thermal performance in a miniature thermosyphon. The nanofluids consisted of de-ionized water and CuO nanoparticles having an average size of 30 nm. The experimental results show that the water-CuO nanofluids can greatly enhance the boiling heat transfer performance of the evaporator in thermosyphon compared with that using water at subatmospheric pressure conditions. A much lower and more uniform wall temperature of the thermosyphon can be obtained by substituting the nanofluids for water. Boiling heat transfer coefficients and the critical heat flux (CHF) of the nanofluids in the evaporator of the thermosyphon have significant increase compared with those of de-ionized water. There was an optimal mass concentration which was estimated to be 1.0 wt % to achieve the maximum heat transfer performance. Operating pressure has very remarkable influences on both the heat transfer coefficients and the CHF of nanofluids, which greatly increase with the decrease of the test pressure. The heat transfer coefficient and the CHF can increase, respectively, about 160% and 120% at the pressure of 7.45 kPa compared with those of water. The experimental study confirmed that the heat transfer performance of the miniature thermosyphon can evidently be strengthened by using water-CuO nanofluids.

Liu, Zhen Hua; Yang, Xue Fei; Guo, Guang Liang

2007-07-01

3

Investigation of the Vibration Effect on the Closed Two-Phase Thermosyphon Operation  

NASA Astrophysics Data System (ADS)

One of the important problems to be solved while designing aircrafts of various purposes is to maintain the necessary temperature inside them. Besides everything it is necessary to equalize the temperature on the surfaces of various aircraft elements for preventing their deformation. The most promising direction when solving the aforementioned problems is the application of heat pipes as an element of the design. Heat pipes are used as highly efficient heat pipe-lines that, being parts of construction elements, permit to equalize the its temperature . As a result of the experiments, it was possible to prove the possibility of using heat pipes as the means for thermostabilization process of the space vehicle. The extension of the areas of application of heat pipes and thermosyphons has resulted in operating in conditions of vibration effects. It is explained to that vibrations are inherent in some units by its nature. Such installations are the space structures, space station, rockets, air and rocket engines, vessels, other transportation facilities. It is considered, that the vibrations improve the heat and mass transfer processes. Therefore it is customary to neglect of vibration actions goes in margin of safety of action of thermal systems. Actually, in accordance with experiences, the vibrations not only improve the heat change, but also degrade it. Therefore knowledge of the impact of vibrations, intrinsic to the installation, on operational modes of used heat pipes and thermosyphons is necessary for preventing breakdown first of all. One of the way of intensification of heat and mass transfer of processes with phase transitions of working fluid is connected with synthetically created vibration actions. In this case also it is necessary to know frequency bands and amplitudes, which one improve or degrade heat and mass transfer. The research of influencing of vibrations on thermal modes with phase changes of working fluids with reference to heat pipes and thermosyphons goes by two paths. One way of research of operational modes is model of heat pipes or thermosyphons in a different variation of frequencies and amplitudes, designs, heat power, working fluid, types of capillary porous structure and so on. Another one is analysis of influencing of vibrations on processes of vaporization, boiling, condensation, flow of two-phase flows in a general formulation regardless to the particular type of a heat pipes. In the report the outcomes of researches of thermal modes of a water thermosyphons in conditions of vibration effects of different frequencies and amplitudes are presented. The boundary frequency bands and amplitude are determined, at which one heat and mass transfer in thermosyphons is improved and is degraded. For an investigated heat pipes of boundary values of frequencies are equal 60 Hz, and amplitudes are equal approximately 3 or 5 mm. The data of other authors are affirmed for another type heat pipes (they received for boundary frequencies 60 and 120-140 Hz). The outcomes of research of influencing of orientation of a heat pipes and thermosyphons on operating of vibrations are submitted. The idealised substantiation's vibration actions on heat and mass transfer of all three zones of thermal tubes - zone of vaporization, condensation and transport are given.

Prisniakov, K.

2002-01-01

4

Harvesting low grade heat to generate electricity with thermosyphon effect of room temperature liquid metal  

NASA Astrophysics Data System (ADS)

Based on thermosyphon effect of room temperature liquid metal, a technical strategy of harvesting low grade heat to generate electricity was proposed. A conceptual system was constructed and an open circuit voltage of 2.62 V with an electrical output power of 110 mW was yielded when the heating power was 45.6 W. This method resolves the difficulty of installing an electric generator in confined space and significantly enlarges the area for converting heat to electricity. Due to its simplicity, avoidance of moving parts, wide working temperature range, and self powering feature, this electric generation system is extremely reliable, completely silent, and flexible.

Li, Peipei; Liu, Jing

2011-08-01

5

Design Parameters for Cryogenic Thermosyphons  

NASA Astrophysics Data System (ADS)

Cryogenic thermosyphons are the thermal conductors of choice for a variety of applications such as conduction-cooled superconducting devices. They exhibit a small effective thermal resistance at small cross-sections. A careful design, however, is crucial to ensure sufficient heat transport for all possible heatloads. The aim of this work is to obtain experimental results on critical limitations and the effective thermal conductivity dependent on the length, the cross-sectional area, and the working liquid fill level of a thermosyphon for different heatloads. For the experiments, a modular thermosyphon was designed with 5 different adiabatic tubes of length [cm]/cross-sectional diameter [cm] 10/1, 10/2, 30/0.5, 30/1, 30/2, which can be mounted between condenser and evaporator. The thermosyphon was operated with different fill levels of either nitrogen or neon and different heatloads. The effective thermal conductivity between condenser and evaporator was determined, dependent on the design parameters mentioned above. Additionally, the useful temperature range of operation was determined, and limitations were monitored and visualized using a built-in camera. The results can support the proper design of thermosyphons for dedicated applications by providing information about the heat transport capability for different thermosyphon design parameters.

Timinger, H.; David, B.; Eckart, R.; Overweg, J.

2008-03-01

6

The Effect of Subcooling on the Flow and Heat Transfer Characteristics in a Two-Phase Loop Thermosyphon  

NASA Astrophysics Data System (ADS)

A two-phase loop thermosyphon is used as a heat transfer device in an energy-saving heat transportation system and so forth, because it transports thermal energy without any external power supply such as a pump under a body force field. We previously performed a fundamental study on the flow and heat transfer characteristics in a two-phase loop thermosyphon installed with a single heated tube evaporator both experimentally and theoretically which was made under the condition of near saturation temperature of liquid in a reservoir. In the present study, the effects of liquid subcooling and the heat input on the circulation mass flow rates, pressure and temperature distributions, and heat transfer coefficients in the evaporator were examined experimentally using water, ethanol, benzene and Freon 113 as the working fluids. On the other hand, the circulation mass flow rates, pressure and temperature distributions were theoretically calculated and compared with the experimental results.

Imura, Hideaki; Takeshita, Kazuhiro; Doi, Kyoji; Noda, Ken-Ichi

7

Heat transfer characteristics of rotating triangular thermosyphon  

NASA Astrophysics Data System (ADS)

An experimental investigation is carried out to study heat transfer characteristics of a rotating triangular thermosyphon, using R-134a refrigerant as the working fluid. The tested thermosyphon is an equilateral triangular tube made from copper material of 11 mm triangular length, 2 mm thickness, and a total length of 1,500 mm. The length of the evaporator section is 600 mm, adiabatic section is 300 mm, and condenser section is 600 mm. The effects of the rotational speed, filling ratio, and the evaporator heat flux on each of the evaporator heat transfer coefficient, he, condenser heat transfer coefficient, hc, and the overall effective thermal conductance, Ct are studied. Experiments are performed with a vertical position of thermosyphon within heat flux ranges from 11 to 23 W/m2 for the three selected filling ratios of 10, 30 and 50 % of the evaporator section volume. The results indicated that the maximum values of the tested heat transfer parameters of the rotational equilateral triangular thermosyphon are obtained at the filling ratio of 30 %. Also, it is found that the heat transfer coefficient of the condensation is increased with increasing the rotational speed. The tested heat transfer parameters of the thermosyphon are correlated as a function of the evaporator heat flux and angular velocity.

Ibrahim, E.; Moawed, M.; Berbish, N. S.

2012-09-01

8

Majorana Thermosyphon Prototype Experimental Setup.  

National Technical Information Service (NTIS)

This report presents the experimental setup of Pacific Northwest National Laboratory's MAJORANA DEMONSTRATOR thermosyphon prototype cooling system. A nitrogen thermosyphon prototype of such a system has been built and tested at PNNL. This document present...

A. D. Guzman D. J. Reid J. T. Munley

2011-01-01

9

The Effect of Wind Speed at the Top of the Tower on the Performance and Energy Generated from _THERMOSYPHON Solar Turbine  

NASA Astrophysics Data System (ADS)

Energy generated from wind turbine depends to a great extent on the wind speed at its inlet. The use of thermosyphon solar tower is an attempt to increase the air velocity at inlet of the wind turbine and of course to increase its power. The wind speed in a certain location changes always with time and with the height above ground surface. In this work, the effect of wind speed at the top of the tower on the performance as well as on the energy generated from thermosyphon solar turbine was studied theoretically. One location in Egypt was chosen for this study. The calculations were achieved mainly with the solar turbine located at tower bottom. For the purpose of comparison, the energy generated from the solar turbine was compared with that generated from free wind turbine at tower height with the absence of solar tower. It was found that, the wind speed at the top of the tower results in a pressure drop which affects the performance of the thermosyphon solar turbine. This pressure drop increases with the rise in wind speed and will be zero only when the wind speed at the top of the tower reaches zero. It was found also that, there is an increase in friction losses through the tower and a decrease in both temperature difference between inlet and outlet of the tower and in heat losses from tower walls with the rise in wind speed in location. The inlet air velocity to the solar turbine and consequently its specific power were found to be increased with the increase in wind speed at the top of the tower. Therefore, the effect of wind speed at the top of the tower must be taken into account during thermosyphon solar tower calculations. By comparing the performance of solar turbine and the free wind turbine located at tower height with the absence of thermosyphon solar tower, it was found that the mean inlet air velocity to the solar turbine located at tower bottom and consequently its specific power are higher than these values for free wind turbine. The mean inlet air velocity to the solar turbine is found to be 117% of its value for a free wind turbine. The yearly specific energy generated from solar turbine is expected to be 157% of its value for free wind turbine.

El-Haroun, A. A.

2002-01-01

10

Effects of auxiliary heater on annual performance of thermosyphon solar water heater simulated under variable operating conditions  

Microsoft Academic Search

A thermosyphon solar water heating system with electric auxiliary heater was simulated using the TRNSYS simulation program. Location of the auxiliary heater, inside the storage tank or connected in series between the system and the user, was studied using the TMY meteorological data for Los Angeles, California. Simulations were performed for two different water load temperatures (60 and 80°C) and

A. M. Shariah; G. O. G. Löf

1997-01-01

11

Majorana Thermosyphon Prototype Experimental Setup  

SciTech Connect

This report presents the experimental setup of Pacific Northwest National Laboratory’s MAJORANA DEMONSTRATOR thermosyphon prototype cooling system. A nitrogen thermosyphon prototype of such a system has been built and tested at PNNL. This document presents the experimental setup of the prototype that successfully demonstrated the heat transfer performance of the system.

Reid, Douglas J.; Guzman, Anthony D.; Munley, John T.

2011-08-01

12

The experimental investigation on thermal performance of a flat two-phase thermosyphon  

Microsoft Academic Search

Electronics cooling has become a key factor for improving the performance of electronic devices. An effective thermal spreader can achieve a more uniform heat flux distribution and thus increase heat dissipation in heat sinks. Two-phase thermosyphon is highly effective thermal spreader. In order to observe boiling and condensation phenomena, a transparent two-phase thermosyphon was prepared for observation and study. The

Ming Zhang; Zhongliang Liu; Guoyuan Ma

2008-01-01

13

The interface effect of carbon nanotube suspension on the thermal performance of a two-phase closed thermosyphon  

NASA Astrophysics Data System (ADS)

An aqueous solution of carbon nanotubes, treated by a concentrated nitric/sulfuric acid mixture to disentangle the nanotubes, was utilized as the working medium in a two-phase closed thermosyphon to investigate its performance. In comparison with the thermosyphon filled with a distilled water medium, the one filled with carbon nanotube suspension has a high evaporation section wall temperature, incipience temperature, and excursion, as well as thermal resistance. The carbon nantotubes' nanofluid deteriorates the performance of the gravity-assisted heat pipe. Measurements employing the maximum bubble pressure method demonstrate that suspending carbon nanotubes in bulk water gives rise to increased surface tension. In addition, the contact angle of suspension obtained with the sessile drop method on a copper plate is much smaller than that of water. Alterations of solid-liquid-vapor interfacial properties, arising from the addition of carbon nanotubes, change the boiling mechanism and thus deteriorate the boiling heat transfer.

Xue, H. S.; Fan, J. R.; Hu, Y. C.; Hong, R. H.; Cen, K. F.

2006-11-01

14

Simulation studies of the position of the auxiliary heater in thermosyphon solar water heating systems  

Microsoft Academic Search

This paper investigates the effect of the physical location of the auxiliary source of energy in thermosyphon solar water heaters and shows that the performance of the system can be optimised with respect to the geometry of the system components. The investigation has been based on a domestic thermosyphon solar water heating system, which was simulated using the TRNSYS programme.

D. R. Wilson

1997-01-01

15

Flexible cryogenic thermosyphon  

NASA Astrophysics Data System (ADS)

Cryocooler and pulse tubes have been increasingly used in small and large scale cryogenic systems including the superconducting magnet systems as heat sinks to attain and keep the required temperatures. Designing the thermal link between the mechanical refrigerator and the system may present a challenge due to the mechanical stresses developed during the cool-down of the assembled systems. Also, the cross section may be too bulky for metallic conductors for given thermal specifications. In this paper, a thermosysphon with a flexible fluid link between the evaporator and condenser is presented. The working fluid used in preliminary testing is nitrogen. The results of the initial testing of the flexible thermosyphon are presented.

Celik, Dogan; Painter, Thomas

2012-06-01

16

Thermosyphon-cooled bellow liquid heat sink  

Microsoft Academic Search

A self contained thermosyphon-cooled flexible bellow liquid heat sink was developed for cooling electronic circuit boards. The prototype system combines the benefits of both flexible bellows and thermosyphon technology. A finned flat-plate thermosyphon was designed and tested for natural convection application under various heat source temperatures. Extensive measurements were made on the combined heat sink system comprising the flat-plate thermosyphon

C. Y. R. Ng; Y. W. Wong; C. Y. Liu; K. F. Choo

1998-01-01

17

Critical Heat Flux of Concentric-Tube Thermosyphon  

NASA Astrophysics Data System (ADS)

An experimental study has been performed to investigate the critical heat flux in a concentric-tube thermosyphon which has the straight shape of an inner tube. The outer tube was 27.4mm in diameter with 1080mm in height. Visual observations and measurments were carried out under the condition of uniform wall heat flux using R-11 and R-113 as the working liquid. The effects of inner tube diameter, insert length of inner tube into reservoir, and liquid subcooling on critical heat flux were extensively discussed. In addition, same experiments of single-tube thermosyphon were carried out for comparison. It was found that critical heat flux characteristics for concentric-tube thermosyphon were classified two regions. The correlation equations of both regions and transition condition were determined.

Kawabe, Hiromichi; Tanaka, Teimi; Fukusako, Shoichiro

18

Performance and modeling of thermosyphon heat exchangers for solar water heaters  

SciTech Connect

Determining the performance of indirect solar heating systems that use thermosyphon heat exchangers requires knowledge of how thermosyphon flow rate and heat exchanger performance vary with operating conditions. In this paper, measured performance of a two-pass, tube-in-shell, double-wall heat exchanger is discussed in terms of modeling issues. Thermosyphon heat exchangers may operate in the developing, mixed convection regime where natural convection effects can significantly influence overall heat transfer and friction coefficients. Existing models which assume the thermal and hydraulic behaviors of thermosyphon heat exchangers are only functions of the thermosyphon and collector flow rates may not be suitable for all heat exchanger types. For example, the overall heat-transfer coefficient-area product for the two-pass, tube-in-shell heat exchanger is best expressed as a function of Reynolds, Grashof, and Prandtl numbers on the thermosyphon side of the heat exchanger. It is proposed that annual simulations of solar water heaters with thermosyphon heat exchangers use this type of relationship to characterize heat transfer in the heat exchanger.

Dahl, S.D.; Davidson, J.H. [Univ. of Minnesota, Minneapolis, MN (United States). Dept. of Mechanical Engineering

1997-08-01

19

Wall shape optimization for a thermosyphon loop featuring corrugated pipes  

NASA Astrophysics Data System (ADS)

In the present paper we address the problem of optimal wall-shape design of a single phase laminar thermosyphon loop. The model takes the buoyancy forces into account via the Boussinesq approximation. We focus our study on showing the effects of wall shape on the flow and on the temperature inside the thermosyphon. To this extend we determine the dependency of the flow rate and the increase in temperature, on the geometrical characteristics of the loop. The geometry considered is a set of axially symmetric corrugated pipes described by a set of parameters; namely the pipe inner radius, the period of the corrugation, the amplitude of the corrugation, and the ratio of expansion and contraction regions of a period of the pipe. The governing equations are solved using the Finite Element Method, in combination with an adaptive mesh refinement technique in order to capture the effects of wall shape. We characterize the effects of the amplitude and of the ratio of expansion and contraction. In particular we show that for a given fixed amplitude it is possible to find an optimal ratio of expansion and contraction that minimizes the temperature inside the thermosyphon. The results show that by adequately choosing the design parameters, the performance of the thermosyphon loop can be improved.

Rosen Esquivel, Patricio I.; ten Thije Boonkkamp, Jan H. M.; Dam, Jacques A. M.; Mattheij, Robert M. M.

2012-06-01

20

Small Scale Thermosyphon Heat Exchanger.  

National Technical Information Service (NTIS)

A small circular heat transfer cell was used to study the cooling of a disc heat source by a thin evaporating liquid film. This small scale thermosyphon is a thermal spreader and a passive heat sink in that the interfacially induced liquid flow rates are ...

M. Sujanani E. W. Kiewra P. C. Wayner

1986-01-01

21

Application of functionalized nanofluid in thermosyphon  

PubMed Central

A water-based functionalized nanofluid was made by surface functionalizing the ordinary silica nanoparticles. The functionalized nanofluid can keep long-term stability. and no sedimentation was observed. The functionalized nanofluid as the working fluid is applied in a thermosyphon to understand the effect of this special nanofluid on the thermal performance of the thermosyphon. The experiment was carried out under steady operating pressures. The same work was also explored for traditional nanofluid (consisting of water and the same silica nanoparticles without functionalization) for comparison. Results indicate that a porous deposition layer exists on the heated surface of the evaporator during the operating process using traditional nanofluid; however, no coating layer exists for functionalized nanofluid. Functionalized nanofluid can enhance the evaporating heat transfer coefficient, while it has generally no effect on the maximum heat flux. Traditional nanofluid deteriorates the evaporating heat transfer coefficient but enhances the maximum heat flux. The existence of the deposition layer affects mainly the thermal performance, and no meaningful nanofluid effect is found in the present study.

2011-01-01

22

Application of functionalized nanofluid in thermosyphon  

NASA Astrophysics Data System (ADS)

A water-based functionalized nanofluid was made by surface functionalizing the ordinary silica nanoparticles. The functionalized nanofluid can keep long-term stability. and no sedimentation was observed. The functionalized nanofluid as the working fluid is applied in a thermosyphon to understand the effect of this special nanofluid on the thermal performance of the thermosyphon. The experiment was carried out under steady operating pressures. The same work was also explored for traditional nanofluid (consisting of water and the same silica nanoparticles without functionalization) for comparison. Results indicate that a porous deposition layer exists on the heated surface of the evaporator during the operating process using traditional nanofluid; however, no coating layer exists for functionalized nanofluid. Functionalized nanofluid can enhance the evaporating heat transfer coefficient, while it has generally no effect on the maximum heat flux. Traditional nanofluid deteriorates the evaporating heat transfer coefficient but enhances the maximum heat flux. The existence of the deposition layer affects mainly the thermal performance, and no meaningful nanofluid effect is found in the present study.

Yang, Xue-Fei; Liu, Zhen-Hua

2011-08-01

23

Experimental Study of Separate Type Thermosyphon  

NASA Astrophysics Data System (ADS)

The passages of vapor flow and the returning liquid flow are perfectly partitioned in a separate type thermosyphon. Therefore the flooding limit can be eliminated and practicability based on its construction is highly evaluated. The carry-over of the liquid into the condensing section accompanied with the rising vapor flow should be avoided in the separate type thermosyphon, since it causes to decrease the heat transfer coefficient on the heat transfer surface in the condenser. In the present work, the effect of liquid level, the heat input into the evaporating section, the charging rate of the liquid, and the dimension of the adiabatic section supposed on the generation of carry-over were studied experimentally. The frequency of the bumping and the velocity of the vapor in the adiabatic section were examined as the function of the termination of the carry-over. The experimental correlation representing the relation among the elapsed time, the liquid temperature and the charging rate of the liquid were also derived.

Hirashima, Masao; Kawahata, Kenya; Negishi, Kanji

24

Heat Transfer Characteristics in a Two-Phase Crank-Shape Closed Thermosyphon  

NASA Astrophysics Data System (ADS)

This paper describes the heat transfer characteristics in a two-phase crank-shape closed thermosyphon. Usually, the thermosyphon is composed of an evaporator, an adiabatic section and a condenser arranged on a straight tube. However, a bent geometry of the thermosyphon is sometimes needed to use because of the limited space for the straight thermosyphon to be installed. Therefore, in the present study, the crank-shape thermosyphon is investigated on the heat transfer coefficients and the critical heat fluxes. The evaporator and the condenser are positioned vertically and the adiabatic section horizontally. The inside diameter of thermosyphon is 16 mm and each length of the evaporator and condenser is 500 mm. As a working fluid, water is used. The inside temperature (the adiabatic wall temperature) is varied from 40 to 80 °C. The distance between the centers of the vertical evaporator and condenser, i. e. , the offset length is varied from 220 to 620 mm, and the effect of the offset length on the heat transfer characteristics is presented.

Imura, Hideaki; Koito, Yasuhi

25

Natural convection in C-shaped thermosyphon  

SciTech Connect

The present work is concerned with the numerical analysis of natural convection from a C-shaped thermosyphon. The system can be considered as a model for a Trombe wall in passive solar collectors as well as electronic cooling arrangements and it has geophysical applications. The effect of Rayleigh number (1 {times} 10{sup 3} to 1 {times} 10{sup 7}) and aspect ratios of 2.0, 4.0, 6.0, and 10.0 is investigated for a fixed Prandtl number (0.7). Local and average Nusselt numbers for heated and cold walls are discussed. Mass advected by the buoyancy force is calculated and presented for the range of investigated parameters. The flow pattern and isotherm distribution in the gap between the wall and cover plate are presented and discussed.

Mohamad, A.A.; Sezai, I. [Eastern Mediterranean Univ., North Cyprus (Turkey). Mechanical Engineering Dept.

1997-08-29

26

Experimental Study on Heat Transfer in an Open Thermosyphon  

NASA Astrophysics Data System (ADS)

Heat transfer coefficient in an open thermosyphon is very small, because the flow in the thermosyphon is confined to a narrow space by the wall of tube with a closed bottom end. Therefore, augmentation of heat transfer due to air injection from the bottom has been suggested. The heat transfer is enhanced by the stirring action of rising bubbles. In response to this, the authors performed an experimental investigation of this subject. Seven test tubes with different diameter and length were employed, and water, ethyl alcohol and ethylene glycol were used as test liquids. The heat transfer coefficients were measured and the effects of air injection rate, tube diameter, tube length and liquid properties were examined. And experimental correlations were presented by using dimensional analysis.

Imura, Hideaki; Kozai, Hiroaki

27

Natural Convection in Annular Duct Forming Thermosyphon.  

National Technical Information Service (NTIS)

The experimental study of the heat transfer for water in an annular duct forming a thermosyphon with a large volume tank, determining correlations for the Nusselt Namber as a function of Rayleigh Number for three diameter ratios is presented. Furthermore,...

S. V. Moeller A. J. Silva Neto

1985-01-01

28

Design and performance evaluation of a compact thermosyphon  

Microsoft Academic Search

Thermosyphons are a promising option for cooling of high heat dissipating electronics. In this paper, the first known implementation of a compact two-phase thermosyphon for cooling of a microprocessor in a commercial desktop computer is presented. The implemented thermosyphon involves four components in a loop: an evaporator with a boiling enhancement structure, a rising tube, a condenser and a falling

Aniruddha Pal; Yogendra K. Joshi; Monem H. Beitelmal; Chandrakant D. Patel; Todd M. Wenger

2002-01-01

29

Cryogenic Nitrogen Thermosyphon Developed and Characterized.  

National Technical Information Service (NTIS)

A two-phase nitrogen thermosyphon was developed at the NASA Glenn Research Center to efficiently integrate a cryocooler into an insulated liquid-nitrogen-filled tank as part of an advanced development zero-boiloff (ZBO) ground test. NASA Marshall Space Fl...

D. W. Plachta R. Christie

2004-01-01

30

Analysis of a transient asymmetrically heated/cooled open thermosyphon  

SciTech Connect

We present a numerical study of transient natural convention in a rectangular open thermosyphon having asymmetric thermal boundary conditions. One vertical wall of the thermosyphon is either heated by constant heat flux ([open quotes]warmup[close quotes]) or cooled by convention to the surroundings ([open quotes]cooldown[close quotes]). The top of the thermosyphon is open to a large reservoir of fluid at constant temperature. The vorticity, energy, and stream-function equations are solved by finite differences on graded mesh. The ADI method and iteration with overrelaxation are used. We find that the thermosyphon performs quite differently during cooldown compared with warmup. In cooldown, flows are mainly confined to the thermosyphon with little momentum and heat exchange with the reservoir. For warmup, the circulation resembles that for a symmetrically heated thermosyphon where there is a large exchange with the reservoir. The difference is explained by the temperature distributions. 25 refs., 12 figs., 1 tab.

Jones, G.F.; Cai, J. (Villanova Univ., PA (United States))

1993-08-01

31

Heat Transfer in a Two-Phase Closed-Loop Thermosyphon  

NASA Astrophysics Data System (ADS)

A two-phase closed-loop thermosyphon is a device which transports heat energy from a heat source to a sink under the body force field and has many practical applications. The critical heat flux of this thermosyphon is larger than that of a non-loop thermosyphon, because the flooding phenomenon occurring in the no-loop one does not occur. In addition, there is another merit that the evaporator and the condencer can be installed in comparatively arbitrary position because these are interconnected by piping. In most previous investigations of the two-phase closed-loop thermosyphons, overall heat resistances were measured. The overall heat resistance, however, consists of three heat resistances; the heat resistances in the evaporator and the condenser, and the transport resistance in the interconnecting pipe. Therefore, we should consider these heat resistances separately. In the present study, we took note of the heat resistances (or heat transfer coefficients) of the evaporator and the condenser. The experiment was performed using two experimental setups and three kinds of test liquid. And, the effects of rotation angle, heat flux, inside temperature (or inside pressure) and liquid charge on the heat transfer coefficients were investigated.

Imura, Hideaki; Saito, Yuji

32

Heat Transport Using Top-heat-type Thermosyphons  

NASA Astrophysics Data System (ADS)

Usual thermosyphons can only transport heat, from lower to higher positions because they utilize the gravitational force for condensed liquid to flow down from an upper condenser to a lower evaporator. On the other hand, top-heat-type thermosyphons must employ some means to pump up the condensed liquid from the lower condenser to the upper evaporator without consuming any power from outside. In the present report, we first describe the design points of usual heat pipe and thermosyphon, and secondly, as the main subject of this report, review the studies on the top-heat-type thermosyphons which have been published so far. Especially, we pick up four kinds of the top-heat-type thermosyphons and explain briefly about them, because they seem to have more practical applicability.

Imura, Hideaki; Koito, Yasushi

33

Heat transfer characteristics of a two-phase closed thermosyphon using different working fluids  

NASA Astrophysics Data System (ADS)

In this paper, an enhanced FORTRAN code was combined with the EES software to predict the vapor flow thermal resistance effects on the heat transfer characteristics of a two- phase closed thermosyphon (TPCT). Different refrigerants such as water, ammonia, R-11, R-22 and R-134a were tested. Also an enhanced time integration scheme was recommended for solving the governing equations in FORTRAN code.

Ziapour, Behrooz Mirzaei; Shaker, Hadi

2010-03-01

34

Heat-Transfer Characteristics in a Concentric-Tube Closed Thermosyphon  

NASA Astrophysics Data System (ADS)

An experimental study has been performed to investigate the heat-transfer characteristics in a concentric-tube closed thermosyphon in which boiling and free convection take place. The outer tube of the thermosyphon used in this study was 100mm in diameter with 3420mm in height, which consisted of both some individual electrical heating copper tubes of 330mm in length and lucite tubes of 60mm in length. On the other hand, inner copper tubes of 41.3mm and 66.6mm in diameter with 3270mm in length were adopted. Experiments were carried out under the constant wall surface temperature conditions and refrigerant R-11 was utilized as a testing fluid. Out of a number of possible controlling valiables, the effect of the heat flux, the void fraction, the ratio of heating length to the total test section length, and the diametric ratio of the concentric tube on the heat-transfer performance were determined.

Kawabe, Hiromichi; Tanaka, Teimi; Fukusako, Shoichiro

35

Titanium-Water Thermosyphon Gamma Radiation Exposure and Results.  

National Technical Information Service (NTIS)

Titanium-water thermosyphons are being considered for use in heat rejection systems for fission power systems. Their proximity to the nuclear reactor will result in some gamma irradiation. Noncondensable gas formation from radiation-induced breakdown of w...

D. A. Goodenow D. A. Jaworske J. L. A. Sanzi

2012-01-01

36

Characteristics of long size thermosyphons made of corrugated tube  

NASA Astrophysics Data System (ADS)

Two-phase closed thermosyphons made of corrugated tube operating in the gravitational field have different characteristics in comparison with that of smooth tube in some items. The cause depends on the accumulated working fluid in the concave space of corrugated tube which tends to induce a dry out phenomenon in the evaporator section. The difference of these characteristics between thermosyphons of corrugated tube and smooth tube seems to amplify with the increment of the length of the thermosyphon. The temperature distribution along the axis of thermosyphon, the heat transport and the heat transfer coefficient as a function of the inclination angle at a fill charge ratio 50 percent of the working fluid were obtained by the experiments and discussed herein. A correlating equation of the heat transfer coefficient was deduced also from the experiments.

Hirashima, Masao; Nishikawa, Yuuji; Taguchi, Masakazu; Negishi, Kanji; Kanero, Ken-Ichi; Matsuoka, Takayoshi

1988-03-01

37

Heat Transfer Characteristics in Crank-Shape Thermosyphons  

NASA Astrophysics Data System (ADS)

A two-phase closed thermosyphon is applied to gas-to-gas heat exchangers, the cooling of heat generation devices, the melting of snow, the prevention from icing of water on roads and so on. Generally, straight tubes are used as the thermosyphon. However, because of the limited space for the straight thermosyphon to be installed, it is considered that a bent thermosyphon is enforced to employ. In response to this, fundamental experiments are conducted on the heat transfer characteristics in a two-phase crank shape closed thermosyphon, in which an evaporator and a condenser are vertically positioned, and a connecting adiabatic section is horizontal. Ethylene glycol aqueous solutions which have lower freezing points and hydrofluoroether 7100 and 7200 which do not contain chloride are used as the working fluids Heat transfer coefficients and critical heat fluxes in the thermosyphon are measured by changing the amount of charged working fluid (0.30,0.40,0.50 and 0.60 of the evaporator volume),the temperature of the adiabatic section (40,50,60,70 and 80°C) and heat flux (from 4.0 kW /m2 to critical). The experimental results are shown and compared with those taken using water as the working fluid.

Imura, Hedeaki; Koito, Yasushi

38

Technology review - Utilizing rotating thermosyphon technology in aircraft thermal management and control  

NASA Astrophysics Data System (ADS)

An evaluation is made of the development status and performance benefits of rotating thermosyphon aircraft thermal management control applications. Rotating two-phase thermosyphons furnish reliable, low maintenance cooling for such rotating systems as electric motors, compressors, and generators. Thermosyphons are uniquely suited for aircraft applications in their insensitivity to operating environments involving high G-loads, vibration, and multiple orientations.

Yerkes, Kirk L.

1990-10-01

39

Deployment, testing and analysis of advanced thermosyphon target systems for production of aqueous fluorine-18 via oxygen-18(p,n)fluorine-18  

NASA Astrophysics Data System (ADS)

Single phase and boiling batch water targets are the most common designs for the cyclotron production of 18F via the 18O(p,n) 18F reaction. Thermosyphon targets have design and operating characteristics which enable higher power operation than conventional boiling targets of like size. Experimental thermosyphon target systems demonstrated the feasibility of high intensity irradiation via bottom pressurized operation. An effective experimental characterization platform was developed and utilized in parallel with computational modeling efforts to further improve designs. A control strategy was also developed to provide a simple and robust means of remote target operation. Clinical production systems were designed and deployed at two facilities.

Stokely, Matthew Hughes

40

Design and Operating Characteristics of a Cryogenic Nitrogen Thermosyphon  

NASA Astrophysics Data System (ADS)

A two-phase nitrogen thermosyphon was developed in order to efficiently integrate a cryocooler into an insulated liquid nitrogen filled tank as part of a Protoflight Zero Boil-Off (ZBO) Development Ground Test. NASA Marshall Space Flight Center's (MSFC) Advanced Space Transportation Program supported this test to improve performance of in-space propulsion system concepts. Active cooling was integrated via a thermosyphon, made of copper, 1070 mm (42'') in length with an inner diameter of 11 mm (0.436''). It was charged with nitrogen to 1.55 MPa (225 PSIA) at 300 K which provided a fill ratio of 15%. The temperatures and heat flows through the thermosyphon were monitored during the start-up phase of the ZBO test and steady-state tests were conducted over a range of increasing and decreasing heat flows. The results showed that the performance of the thermosyphon exceeded expectations and had a thermal resistance of 0.2 K/W at a heat flow of 8.0 W. The design calculations also showed that the thermal resistance of a thermosyphon can be made relatively constant over a wider range of heat flows by making the ratio of evaporator area to condenser area 3:1.

Christie, R.; Robinson, D.; Plachta, D.

2004-06-01

41

Heat transfer characteristics of a two-phase closed thermosyphon using de ionized water mixed with silver nano  

NASA Astrophysics Data System (ADS)

Effect of using silver nanofluid (De Ionize water mixed with silver nano and particles less than 100 nm.) on heat transfer characteristics of a two-phase closed thermosyphon at normal operating condition was investigated in this research. The thermosyphon made by copper tube with 7.5, 11.1 and 25.4 mm ID. The filling ratios of 30, 50 and 80% by evaporator length and aspect ratios of 5, 10, and 20 (Le/ d i ) with vertical position. Pure water and DI water mixed with silver nanofluid of us as working fluid to compare. The working temperatures were 40, 50 and 60°C. It was found that, the maximum hat transfer rate of 750.81 W, with aspect ratio of 20(diameter of 25.4 mm ID) and working temperature of 60°C. The DI water mixed silver nanofluids more than approximate 70% to compare with pure water.

Paramatthanuwat, T.; Boothaisong, S.; Rittidech, S.; Booddachan, K.

2010-03-01

42

Application of silver nanofluid containing oleic acid surfactant in a thermosyphon economizer  

NASA Astrophysics Data System (ADS)

This article reports a recent study on the application of a two-phase closed thermosyphon (TPCT) in a thermosyphon for economizer (TPEC). The TPEC had three sections of equal size; the evaporator, the adiabatic section, and the condenser, of 250 mm × 250 mm × 250 mm ( W × L × H). The TPCT was a steel tube of 12.7-mm ID. The filling ratios chosen to study were 30, 50, and 80% with respect to the evaporator length. The volumetric flow rates for the coolant (in the condenser) were 1, 2.5, and 5 l/min. Five working fluids investigated were: water, water-based silver nanofluid with silver concentration 0.5 w/v%, and the nanofluid (NF) mixed with 0.5, 1, and 1.5 w/v% of oleic acid (OA). The operating temperatures were 60, 70, and 80°C. Experimental data showed that the TPEC gave the highest heat flux of about 25 kW/m2 and the highest effectiveness of about 0.3 at a filling ratio of 50%, with the nanofluid containing 1 w/v% of OA. It was further found that the effectiveness of nanofluid and the OA containing nanofluids were superior in effectiveness over water in all experimental conditions came under this study. Moreover, the presence of OA had clearly contributed to raise the effectiveness of the nanofluid.

Parametthanuwat, Thanya; Rittidech, Sampan; Pattiya, Adisak; Ding, Yulong; Witharana, Sanjeeva

2011-12-01

43

Application of silver nanofluid containing oleic acid surfactant in a thermosyphon economizer.  

PubMed

This article reports a recent study on the application of a two-phase closed thermosyphon (TPCT) in a thermosyphon for economizer (TPEC). The TPEC had three sections of equal size; the evaporator, the adiabatic section, and the condenser, of 250 mm × 250 mm × 250 mm (W × L × H). The TPCT was a steel tube of 12.7-mm ID. The filling ratios chosen to study were 30, 50, and 80% with respect to the evaporator length. The volumetric flow rates for the coolant (in the condenser) were 1, 2.5, and 5 l/min. Five working fluids investigated were: water, water-based silver nanofluid with silver concentration 0.5 w/v%, and the nanofluid (NF) mixed with 0.5, 1, and 1.5 w/v% of oleic acid (OA). The operating temperatures were 60, 70, and 80°C. Experimental data showed that the TPEC gave the highest heat flux of about 25 kW/m2 and the highest effectiveness of about 0.3 at a filling ratio of 50%, with the nanofluid containing 1 w/v% of OA. It was further found that the effectiveness of nanofluid and the OA containing nanofluids were superior in effectiveness over water in all experimental conditions came under this study. Moreover, the presence of OA had clearly contributed to raise the effectiveness of the nanofluid. PMID:21711856

Parametthanuwat, Thanya; Rittidech, Sampan; Pattiya, Adisak; Ding, Yulong; Witharana, Sanjeeva

2011-04-07

44

Analysis and performance evaluation of an air thermosyphon system  

Microsoft Academic Search

The study deals with the analysis and simulation development of an air thermosyphon system. The physical system consists of a double glazed collector, ducting, backdraft dampers to prevent reverse circulation of the air, and a rock box in the north wall for thermal storage. A simulation scheme has been developed to conduct a preliminary system evaluation. The simulation makes use

L. S. Marshall; P. J. Burns; C. B. Winn

1980-01-01

45

Flexible two-phase thermosyphon for power electronic cooling  

Microsoft Academic Search

A two phase thermosyphon system for power electronic cooling is presented. The designed evaporator can house multiple power electronics modules, it collects the generated vapor to a common flexible tube that drives the vapor to a plate heat exchanger condenser. The system was tested and simulated for a total power loss of 12.5 kW. The condenser was installed at a

Francesco Agostini; Bruno Agostini

2011-01-01

46

Theoretical Design of a Thermosyphon for Efficient Process Heat Removal from Next Generation Nuclear Plant (NGNP) for Production of Hydrogen  

SciTech Connect

The work reported here is the preliminary analysis of two-phase Thermosyphon heat transfer performance with various alkali metals. Thermosyphon is a device for transporting heat from one point to another with quite extraordinary properties. Heat transport occurs via evaporation and condensation, and the heat transport fluid is re-circulated by gravitational force. With this mode of heat transfer, the thermosyphon has the capability to transport heat at high rates over appreciable distances, virtually isothermally and without any requirement for external pumping devices. For process heat, intermediate heat exchangers (IHX) are required to transfer heat from the NGNP to the hydrogen plant in the most efficient way possible. The production of power at higher efficiency using Brayton Cycle, and hydrogen production requires both heat at higher temperatures (up to 1000oC) and high effectiveness compact heat exchangers to transfer heat to either the power or process cycle. The purpose for selecting a compact heat exchanger is to maximize the heat transfer surface area per volume of heat exchanger; this has the benefit of reducing heat exchanger size and heat losses. The IHX design requirements are governed by the allowable temperature drop between the outlet of the NGNP (900oC, based on the current capabilities of NGNP), and the temperatures in the hydrogen production plant. Spiral Heat Exchangers (SHE’s) have superior heat transfer characteristics, and are less susceptible to fouling. Further, heat losses to surroundings are minimized because of its compact configuration. SHEs have never been examined for phase-change heat transfer applications. The research presented provides useful information for thermosyphon design and Spiral Heat Exchanger.

Piyush Sabharwall; Fred Gunnerson; Akira Tokuhiro; Vivek Utgiker; Kevan Weaver; Steven Sherman

2007-10-01

47

Thermal performance of plate-type loop thermosyphon at sub-atmospheric pressures  

Microsoft Academic Search

This experimental study examines the thermal performance of a newly devised plate-type two-phase loop thermosyphon with cooling applications to electronic boards of telecommunication systems. The evaporation section is configured as the inter-connected multi channels to emulate the bridging boiling mechanism in pulsating thermosyphon. Two thermosyphon plates using water as the coolant with filling ratios (FR) of 0.22 and 0.32 are

Vadim Tsoi; Shyy Woei Chang; Kuei Feng Chiang; Chuan Chin Huang

2011-01-01

48

Thermosyphon coil arrangement for heat pump outdoor unit  

DOEpatents

For a heat pump, the outdoor unit is provided with a coil and a refrigerant flow arrangement therefor which is such that in the heating mode of operation of the heat pump they operate in a thermosyphon fashion. The coil 32 has a feed portion 30 and an exit portion 34 leading to a separator drum 36 from which liquid refrigerant is returned through downcomer line 42 for recirculation to the feed portion. The coil is tilted upwardly from entry to exit by the angle alpha to enhance the clearance of the two phases of refrigerant from each other in the heating mode of operation. There is no thermosyphon function in the cooling mode of operation.

Draper, Robert (Churchill, PA)

1984-01-01

49

Thermosyphon coil arrangement for heat pump outdoor unit  

DOEpatents

For a heat pump, the outdoor unit is provided with a coil and a refrigerant flow arrangement there for which is such that in the heating mode of operation of the heat pump they operate in a thermosyphon fashion. The coil has a feed portion and an exit portion leading to a separator drum from which liquid refrigerant is returned through downcomer line for recirculation to the feed portion. The coil is tilted upwardly from entry to exit by the angle alpha to enhance the clearance of the two phases of refrigerant from each other in the heating mode of operation. There is no thermosyphon function in the cooling mode of operation. 9 figs.

Draper, R.

1984-05-22

50

Start-up from the frozen state of two-phase thermosyphons  

Microsoft Academic Search

In a cold region, ethylene glycol or propylene glycol aqueous solution is usually used as a working fluid of thermosyphons, because if pure water is used as a working fluid, the thermosyphon tube breaks due to the volume expansion of ice when water freezes into ice. If a non-freeze working fluid is required, for example, under the environmental temperature of

Hideaki Imura; Yasushi Koito; Masataka Mochizuki; Haruhito Fujimura

2005-01-01

51

Performance rating method of thermosyphon solar water heaters  

Microsoft Academic Search

A rating method for the thermal performance of thermosyphon solar water heaters was developed. Except that the outdoor test procedure still follows the Taiwan Standard CNS B7277, a system characteristic efficiency [eta][sub s]* which is defined as the [alpha][sub o], value corrected at M\\/A[sub c]= 75 kg\\/m[sup 2], was derived so that [eta][sub s]* is independent of the M\\/A, ratio.

B HUANG

1993-01-01

52

A school building reclad with thermosyphoning air panels  

Microsoft Academic Search

Thermosyphoning air panels (TAPs) were installed as part of the refurbishment of a school building in south-east England. Design, construction, and operation are described. Their long-term thermal performance was monitored extensively. Annual contributions to the heating load were 1970 kWh for the 23 m[sup 2] of south-facing TAPs, and 498 kWh for the 27.3 m[sup 2] of east-facing TAPs during

S. N. G. Lo; B. Norton; C. R. Deal

1994-01-01

53

The measured performance of an air thermosyphon system  

NASA Astrophysics Data System (ADS)

A simulation scheme was developed to evaluate a passive air thermosyphon system consisting of a double glazed collector, ducting, backdraft dampers to prevent reverse circulation of the air, and a rock box in the north wall for thermal storage. A test cell been constructed in order to obtain actual data. Temperature measurements and flow visualization in the air ducts are studied. The thermal performance of the system is evaluated by using measured data as input for the simulation model.

Marshall, L. S.; Burns, P. J.; Winn, C. B.

54

Determination of the operation range of a vertical two-phase closed thermosyphon  

NASA Astrophysics Data System (ADS)

A comprehensive model, proposed for a vertical two-phase closed thermosyphon (TPCT) by the present authors, is further developed by utilizing the criteria for dryout, flooding and boiling limits to investigate the effects of filling ratio on them together, while the available models can just consider one or two limits of them. A new concept named dryout ratio is proposed, which can be used for predicting dryout limit. The empirical correlation and the empirical value, provided by other researchers, are used for predicting flooding and boiling limit, respectively. The experiments with nitrogen as working fluid are performed, and compared with the calculations. The maximum filling ratio is introduced, beyond which the liquid could be carried to condenser and the heat transfer performance can be deteriorated. And then the closed operation range of a vertical TPCT is finally determined, which has not been reported before. The effects of operating pressure and geometries on the range are also analyzed.

Jiao, B.; Qiu, L. M.; Gan, Z. H.; Zhang, X. B.

2012-06-01

55

Flow and Heat Transfer Characteristics in a Closed-Type Two-Phase Loop Thermosyphon  

NASA Astrophysics Data System (ADS)

A closed-loop two-phase thermosyphon can transport a large amount of thermal energy with small temperature differences without any external power supply. A fundamental investigation of flow and heat transfer characteristics was performed experimentally and theoretically using water, ethanol and R113 as the working liquids. Heat transfer coefficients in an evaporator and a condenser, and circulation flow rates were measured experimentally. The effects of liquid fill charge, rotation angle, pressure in the loop and heat flux on the heat transfer coefficients were examined. The heat transfer coefficients in the evaporator and the condenser were correlated by the expressions for pool boiling and film condensation respectively. As a result, the heat transfer coefficients in the evaporator were correlated by the Stephan-Abdelsalam equations within a±40% error. Theoretically, the circulation flow rate was predicted by calculating pressure, temperature, quality and void fraction along the loop. And, the comparison between the calculated and experimental results was made.

Imura, Hideaki; Saito, Yuji; Fujimoto, Hiromitsu

56

Analysis and performance evaluation of an air thermosyphon system  

SciTech Connect

The study deals with the analysis and simulation development of an air thermosyphon system. The physical system consists of a double glazed collector, ducting, backdraft dampers to prevent reverse circulation of the air, and a rock box in the north wall for thermal storage. A simulation scheme has been developed to conduct a preliminary system evaluation. The simulation makes use of an improved Euler technique to solve the transient energy and momentum equations. The formulation of the analytical model for the system is presented. Simulation results and the variation of system parameters are also analyzed.

Marshall, L.S.; Burns, P.J.; Winn, C.B.

1980-01-01

57

Analysis of thermosyphoning in a steam generator model  

SciTech Connect

An analysis of thermosyphoning in a stream generator model is presented. The model considers the transient development of buoyancy-driven steam flow in the steam generator tubing, secondary side heat transfer and an inlet plenum mixing model. Numerical solutions are obtained for conditions intended to simulate the natural circulation phenomena in a 3-Loop pressurized water reactor in a loss-of-coolant accident scenario. The relation between the circulation rate and the heating rate is determined. The sensitivity of the model to various key parameters is examined. 16 refs.

Martinez, M.J.; Martinez, G.M.

1991-10-01

58

Laminar flow modelling of a thermosyphon loop at specified wall temperatures  

NASA Astrophysics Data System (ADS)

A thermosyphon loop is analyzed in this study by use of numerical and experimental techniques. A rectangular loop was constructed using copper pipe and the sections which were heated or cooled were designed as concentric tube heat exchangers. Hot or cold water was circulated outside of these sections, and both the surface temperatures and heat transferred to and from the loop were measured. Within the numerical study both the momentum and energy equations were also solved using a SIMPLEX algorithm. Numerical results were obtained for laminar flow within the circuit when there was uniform wall temperature in the vertically heated and cooled sections of the thermosyphon. The two-dimensional numerical model provided results which agree with those found experimentally from the thermosyphon loop. In addition, a simulation model was constructed using a correlation included both the Grashof and Prandtl numbers to evaluate heat transfer through a thermosyphon loop.

Küçüka, Serhan; Ba?aran, Tahsin

2007-10-01

59

Experimental study on transient behavior of semi-open two-phase thermosyphon.  

PubMed

An experimental system was set up to measure the temperature, pressure, heat transfer rate and mass flow rate in a semi-open two-phase thermosyphon. The behaviors of a semi-open two-phase thermosyphon during startup, shutdown and lack of water were studied to get complete understanding of its thermal characteristics. The variation of wall temperature, heat-exchange condition and pressure fluctuations of semi-open two-phase thermosyphons showed that the startup of SOTPT needs about 60-70 min; the startup speed of SOTPT is determined by the startup speed of the condensation section; the average pressure in the heat pipe is equal to the environmental pressure usually; the shutdown of SOTPT needs about 30-50 min; a semi-open two-phase thermosyphon has good response to lack of water accident. PMID:15547965

Zhu, Hua; Wang, Jian-Xin; Zhang, Qiao-Hui; Tu, Chuan-Jing

2004-12-01

60

Application of thermosyphon air-preheater for energy thrift from a furnace in a hot forging process  

Microsoft Academic Search

This research studied the heat transfer of the thermosyphon air-preheater. An empirical model was developed to predict heat\\u000a transfer and applied to compute the thermosyphon air-preheater in a hot brass forging process. The thermosyphon air-preheater\\u000a was designed, constructed and tested under medium temperature operating conditions with inlet hot gases, ranging between 390–440\\u000a °C in terms of using water as the

L. Yodrak; S. Rittidech; N. Poomsa-ad

2011-01-01

61

The liquid helium thermosyphon for the GEM detector magnet  

SciTech Connect

The GEM detector magnet, a horizontal solenoid 19.5 m in diameter and wound with a niobium-titanium cable in conduit, will be located with it`s axis 19.5 m below grade. The conductor is wound on the inside of an aluminum bobbin which is cooled by liquid helium which flows by natural convection in a thermosyphon loop from a large storage dewar located at the ground surface. The function of the thermosyphon system is to absorb the environmental heat load as well as any internally generated heat. In the first category is included that heat which is transfered to the magnet by way of the mechanical supports, the insulation and the current leads. The internally generated heat includes the resistive heating within the normally conducting conductor splices and the inductive heating of the bobbin during current transients. Though similar systems have been employed elsewhere, there are some unique aspects to the present design. By taking advantage of the large vertical head available, the parallel heat exchanger passes within the magnet remain sub-cooled, thus insuring single phase coolant within the magnet. It is believed that this will be the first instance of such a large vertical head being used to this advantage in a helium system.

Warren, R.P.

1993-05-04

62

Development of a thermoelectric refrigerator with two-phase thermosyphons and capillary lift  

Microsoft Academic Search

A thermoelectric domestic refrigerator has been developed, with a single compartment of 0.225m3, for food preservation at 5°C. The cooling system is made up of two equal thermoelectric devices, each composed of a Peltier module (50W) with its hot side in contact with a two-phase and natural convection thermosyphon (TSV) and a two-phase and capillary lift thermosyphon (TPM), in contact

J. G. Vián; D. Astrain

2009-01-01

63

Development of a flexible thermosyphon for cooling a concentrated heat source  

Microsoft Academic Search

A flexible tubular thermosyphon was developed for the purpose of cooling a concentrated heat source. Designed to fold 180° for storage and unfold for operation, the thermosyphon is made of copper and uses water as the working fluid. Its integral flex-joint has several advantages over conventional flexible joints. A unique boiling enhancement improved the liquid-to-vapor phase change while minimizing the

R. S. McKee; F. D. Hobbs

1995-01-01

64

Thermal performance analysis of nanofluids in a thermosyphon heat pipe using CFD modeling  

NASA Astrophysics Data System (ADS)

A computational fluid dynamics model for simulation of a thermosyphon with two-phase flow including phase change heat transfer was developed. De-ionized water and CuO/Water nanofluid were used as working fluids in the thermosyphon. Results show that, maximum heat flux of the nanofluid is about 46 % higher than that of water. Also by increasing the nanofluid concentration, the wall temperature decreases, and the concentration of 1 wt% is the optimum concentration.

Asmaie, L.; Haghshenasfard, M.; Mehrabani-Zeinabad, A.; Nasr Esfahany, M.

2013-05-01

65

Visualization of Flow Pattern in Thermosyphon by ECT  

NASA Astrophysics Data System (ADS)

An investigation on the visualization of the flow of the liquid in a two-phase closed thermosyphon (TPCT) is carried out. Electrical capacitance tomography (ECT) with optimal step lengths for iterative image reconstruction algorithm is applied in the study. Measurements are made under a range of heating rates of the TPCT. As against the common assumption of ``low spatial resolution of ECT'', the experimental results have demonstrated ECT's capability of reconstructing images of thin films on the order of 100 ?m in thickness. Results for film thickness by ECT are compared with the established theory. Agreements and discrepancies are observed among the reconstructed images corresponding to difference thresholds. ECT images of the liquid distributions in the TPCT show clear dependence on the variation of working conditions, which proves the potential of ECT as an advantageous technique for monitoring the operation of TPCT.

Liu, Shi; Li, Jingtao; Chen, Qi

2007-06-01

66

Heat transfer characteristics of two-phase thermosyphon heat pipe. I - Boiling heat transfer correlation in heating section  

Microsoft Academic Search

A correlation for the boiling heat transfer coefficient in the heating section of a two-phase thermosyphon heat pipe is developed in comparison with experimental data. The experiments are conducted for a vertically oriented thermosyphon pipe using three kinds of working fluid, water, Feron R 113, and ethanol, at a wide pressure range of 0.1 to 20 bar and a fill

Fumito Kaminaga; Yoshizo Okamoto

1992-01-01

67

Observations on an evaporative, elbow thermosyphon  

SciTech Connect

The performance of the evaporative elbow system was found to be superior to that of the nonevaporative system, but comparable to the performance of the linear system. The parametric role of the evaporator wall temperature, the condenser wall temperature, and the vapor saturation temperature was demonstrated, each revealing a similar monotonic effect. With the evaporator upright, the data were found to be similar to, but displaced from, the upright condenser data. The upright evaporator gave the better performance, but not overwhelmingly so. The limit of performance with the condenser upright was found to be dictated by evaporator dryout. In the upright evaporator configuration, the limit may be attributed to flooding in the poorly draining condenser; this limit was indistinguishable from geyser behavior at low vapor pressures. 16 refs., 3 figs.

Lock, G.S.H.; Fu, J. (Univ. of Alberta, Edmonton (Canada))

1993-05-01

68

Impact of cooling condition and filling ratio on heat transfer limit of cryogenic thermosyphon  

NASA Astrophysics Data System (ADS)

In this study, the heat transfer limits of two cryogenic thermosyphons with different cooling conditions and filling ratios are experimentally studied and discussed. The cryogenic thermosyphons are fabricated with the same inner structures and their heat transfer performances are tested. The heat transfer limit of the cryogenic thermosyphon can reach 180.0 W through improving the cooling condition at moderate filling ratios. Meanwhile, it is found that the dry-out limit occurs not only at low filling ratios, but also at high filling ratios in the case of poor cooling condition. The mechanism behind the dry-out limit at high filling ratios is analyzed and the critical heat flux is predicted by a model that describes the heat and mass balance of the working fluid. A fluctuating period is observed in the vicinity of the boiling limit, and the critical heat flux corresponding to the boiling limit is predicted by an empirical correlation.

Long, Z. Q.; Zhang, P.

2012-01-01

69

Local thermal cycles determination in thermosyphon-cooled traction IGBT modules reproducing mission profiles  

Microsoft Academic Search

Temperature mapping in two IGBT modules cooled by a thermosyphon-based system is performed under realistic power mission profiles. The power mission profiles are inferred from a traction design tool results based on feedback data extracted from the field, in which the service line, the train characteristics, and its speed profile are taken into account. Thereby, the chips which are more

X. Perpiñà; M. Piton; Michel Mermet-Guyennet; Xavier Jordà; José Millán

2007-01-01

70

Experimental investigation of the heat transfer characteristics of a helium cryogenic thermosyphon  

NASA Astrophysics Data System (ADS)

The heat transfer performance of a cryogenic thermosyphon filled with helium as the working fluid is investigated experimentally with a G-M cryocooler as the heat sink in this study. The cryogenic thermosyphon acts as a thermal link between the cryocooler and the cooled target (the copper evaporator with a large mass). Helium is charged in different filling ratios, and the cooling down process and the heat transfer characteristics of the cryogenic thermosyphon are investigated. The cooling down process of the cooled target can be significantly accelerated by the presence of helium in the cryogenic thermosyphon and the cooling down period can be further shortened by the increase of filling ratio. The heat transfer mode changes from the liquid-vapor phase change to natural convection as the increase of the heating power applied on the evaporator. The heat transfer limit and thermal resistance are discussed for the liquid-vapor phase change heat transfer, and they can be estimated by empirical correlations. For the natural convection heat transfer, it can be enhanced by increasing the filling ratio, and the natural convection of supercritical helium is much stronger than that of gaseous helium.

Long, Z. Q.; Zhang, P.

2013-10-01

71

Characteristics and Flow Visualization of a Thermosyphon in Melts Inside a Composite Heat Exchanger Tube  

Microsoft Academic Search

The characteristics of a thermosyphon in molten aluminum inside the annulus of a composite heat exchanger tube has been studied. The physical system consists of two concentric, hollow, carbon steel cylinders press-fitted with a hollow aluminum cylinder in the annulus. It is heated by a helical electric heater wound around the outer surface and is cooled by air flowing through

Wen-Jei Yang; Nengli Zhang; C. P. Lee; Yuen-Sang Ho; Jeff Chiou

1990-01-01

72

An Experimental Study on Heat Transfer Coefficients of a CO2Filled Thermosyphon  

Microsoft Academic Search

Because carbon dioxide is ozone friendly and has negligible global warming potential, it has received renewed interest in recent years as an important alternative refrigerant. In this article, the heat transfer characteristics of a carbon dioxide-filled two-phase closed thermosyphon were investigated experimentally, and the empirical heat transfer correlations are reported. The heat transfer data were analyzed, and heat transfer coefficients

S. J. Jeong

2011-01-01

73

A reduced-order partial differential equation model for the flow in a thermosyphon  

NASA Astrophysics Data System (ADS)

Flow in a closed-loop thermosyphon heated from below exhibits a sequence of bifurcations with increasing Grashof number. Using the Navier Stokes equations in the Boussinesq approximation we have derived a model where, in the case of a slender circular loop, the first Fourier modes exactly decouple from all other Fourier modes, leaving a system of three coupled nonlinear partial differential equations that completely describes the flow in the thermosyphon. We have characterized the flow through two bifurcations, identifying stable periodic solutions for flows of Prandtl number greater than 18.5, a much lower value than predicted previously. Because of the quadratic nonlinearity in this system of equations, it is possible to find the global stability limit, and we have proved that it is identical to the first bifurcation point.

Burroughs, E. A.; Coutsias, E. A.; Romero, L. A.

2005-10-01

74

Improving load matching characteristics of a thermosyphonic solar system by thermostatically controlled circulation  

SciTech Connect

The load matching characteristics of a thermosyphonic solar water heater can be improved by utilizing a thermostatic flow control (TFC). Simulation of the performance of a typical thermosyphonic domestic solar heater, with and without a TFC, was used to evaluate the yearly requirement of auxiliary energy to meet four different loads. The amount of yearly auxiliary energy required to fully match the load demands is used as a measure of the matching improvement. Results indicate that, for load temperatures of 40[degrees], 60[degrees], and 70[degrees] C, the thermostatic flow controller improves the system's (multi- or single-pass) performance, while the common single-pass system without the thermostatic flow controller is the best choice for a 50[degrees]C load temperature.

Arbel, A. (Institute of Agricultural Engineering, Bet Dagan (Israel)); Sokolov, M. (Tel-Aviv Univ., Ramat-Aviv (Israel))

1994-04-01

75

Closed Loop Two-Phase Thermosyphon of Small Dimensions: a Review of the Experimental Results  

Microsoft Academic Search

A bibliographical review on the heat and mass transfer in gravity assisted Closed Loop Two Phase Thermosyphons (CLTPT) with\\u000a channels having a hydraulic diameter of the order of some millimetres and input power below 1 kW is proposed. The available\\u000a experimental works in the literature are critically analysed in order to highlight the main results and the correlation between\\u000a mass flow

Alessandro Franco; Sauro Filippeschi

76

Test results on a thermosyphon concept to high-power cool desktop computers and servers  

Microsoft Academic Search

This paper reports measured thermal performance of two prototype thermo-syphon devices designed to cool desktop computers and servers. The prototype was designed to reject 100 W with 35 K CPU-to-air temperature difference using an 80 mm 3350 rpm fan for air flow. One prototype is aluminum and uses R-134A, while the other is copper and uses water. The working fluid

R. L. Webb; Shinobu Yamauchi; Showa Denko

2002-01-01

77

Instability of condensate film and capillary blocking in small-diameter-thermosyphon condensers  

Microsoft Academic Search

Instability of the condensate film in a small-diameter-tube condenser was investigated by using an integro-differential approach. The disturbance wave parameters were predicted based on the characteristic equation derived in this study, and the results were in good agreement with the available experimental data reported in the literature. Capillary blocking taking place in a small-diameter-thermosyphon condenser was also examined. The proposed

H. Teng; P. Cheng; T. S. Zhao

1999-01-01

78

Thermal performance of sub-atmospheric loop thermosyphon with and without enhanced boiling surface  

Microsoft Academic Search

This experimental study comparatively examines the thermal performances of two-phase loop thermosyphons (TPLP) with and without enhanced boiling surface at sub-atmospheric pressures. The boiling instabilities along with the constituent and total thermal resistances of these TPLPs are analyzed with the aid of boiling flow structures imaged at sub-atmospheric pressures. Boiling heat flux (Q) and thermal resistance of condenser (Rth,con) are

S. W. Chang; K. F. Chiang; C.-C. Huang

2012-01-01

79

Modeling analysis of bubble flow regime in a closed two-phase thermosyphon  

NASA Astrophysics Data System (ADS)

Predictions of the operating liquid level in the evaporator of a closed two-phase thermosyphon (gravity heat pipe) are given throughout a simplified analysis which takes the influence of the dimension and condensation heat transfer in the condenser of the heat pipe into account. In order to verify the accuracy of our model comparison of the present study with some published results is made by means of computational examples.

Tang, Zhi-Wei; Han, Ya-Fang; Liu, Ai-Jie; Song, Wei-Gang

2011-12-01

80

An experiment on thermosyphon boiling in uniformly heated vertical tube and asymmetrically heated vertical channel  

Microsoft Academic Search

Continuing efforts to achieve increased circuit performance in electronic package have resulted in higher power density at\\u000a chip and module level. As a result, the thermal management of electronic package has been important in maintaining or improving\\u000a the reliability of the component. An experimental investigation of thermosyphonic boiling in vertical tube and channel made\\u000a by two parallel rectangular plates was

Jin-Seok Jeon; Jung Hee Na; Hong Chul Park; Ho-Young Kwak

2001-01-01

81

Thermosyphon Cooling System for the Siemens 400kW HTS Synchronous Machine  

NASA Astrophysics Data System (ADS)

A commercial GM cryocooler is employed to cool the rotor of the first Siemens 400 kW HTS machine. Excellent thermal connection between cold head and rotor is achieved using a thermosyphon. At the rotor's inner surface the required cooling power is provided by evaporating fluid, that is recondensed at the coldhead. Our configuration allows an easy mechanical decoupling of the stationary cold head and the rotor, using a magnetic liquid rotary seal. In order to shorten cool-down time, a precool to 70 K is done with a thermosyphon filling of nitrogen, while a motor operating temperature of 25 K is reached using neon. Temperature difference between the thermosyphon's cold and warm ends is below 1 K for a heat transfer of 40 W. During operation, a temperature controller stabilizes condenser temperature and hence rotor temperature. The self-regulating cooling system has been operated continuously and without problems since Spring 2001. The machine was also operated with newly developed pulse-tube cryocoolers, that are in development to take benefit of their expected prolonged service intervals.

Frank, M.; Frauenhofer, J.; Gromoll, B.; van Haßelt, P.; Nick, W.; Nerowski, G.; Neumüller, H.-W.; Häfner, H.-U.; Thummes, G.

2004-06-01

82

Computer cooling using a two phase minichannel thermosyphon loop heated from horizontal and vertical sides and cooled from vertical side  

NASA Astrophysics Data System (ADS)

In the present paper it is proposed to consider the computer cooling capacity using the thermosyphon loop. A closed thermosyphon loop consists of combined two heaters and a cooler connected to each other by tubes. The first heater may be a CPU processor located on the motherboard of the personal computer. The second heater may be a chip of a graphic card placed perpendicular to the motherboard of personal computer. The cooler can be placed above the heaters on the computer chassis. The thermosyphon cooling system on the use of computer can be modeled using the rectangular thermosyphon loop with minichannels heated at the bottom horizontal side and the bottom vertical side and cooled at the upper vertical side. The riser and a downcomer connect these parts. A one-dimensional model of two-phase flow and heat transfer in a closed thermosyphon loop is based on mass, momentum, and energy balances in the evaporators, rising tube, condenser and the falling tube. The separate two-phase flow model is used in calculations. A numerical investigation for the analysis of the mass flux rate and heat transfer coefficient in the steady state has been accomplished.

Bieli?ski, Henryk; Mikielewicz, Jaros?aw

2010-10-01

83

RELAP5 Model of a Two-phase ThermoSyphon Experimental Facility for Fuels and Materials Irradiation  

SciTech Connect

The High Flux Isotope Reactor (HFIR) at Oak Ridge National Laboratory (ORNL) does not have a separate materials-irradiation flow loop and requires most materials and all fuel experiments to be placed inside a containment. This is necessary to ensure that internal contaminants such as fission products cannot be released into the primary coolant. As part of the safety basis justification, HFIR also requires that all experiments be able to withstand various accident conditions (e.g., loss of coolant) without generating vapor bubbles on the surface of the experiment in the primary coolant. As with any parallel flow system, HFIR is vulnerable to flow excursion events when vapor is generated in one of those flow paths. The effects of these requirements are to artificially increase experiment temperatures by introducing a barrier between the experimental materials and the HFIR coolant and to reduce experiment heat loads to ensure boiling doesn t occur. A new experimental facility for materials irradiation and testing in the HFIR is currently being developed to overcome these limitations. The new facility is unique in that it will have its own internal cooling flow totally independent of the reactor primary coolant and boiling is permitted. The reactor primary coolant will cool the outside of this facility without contacting the materials inside. The ThermoSyphon Test Loop (TSTL), a full scale prototype of the proposed irradiation facility to be tested outside the reactor, is being designed and fabricated (Ref. 1). The TSTL is a closed system working as a two-phase thermosyphon. A schematic is shown in Fig. 1. The bottom central part is the boiler/evaporator and contains three electric heaters. The vapor generated by the heaters will rise and be condensed in the upper condenser, the condensate will drain down the side walls and be circulated via a downcomer back into the bottom of the boiler. An external flow system provides coolant that simulates the HFIR primary coolant. The two-phase flow code RELAP5-3D (Ref. 2) is the main tool employed in this design. The model has multiple challenges: boiling, condensation and natural convection flows need to be modeled accurately.

Carbajo, Juan J [ORNL; McDuffee, Joel Lee [ORNL

2013-01-01

84

Heat Transfer Characteristics of the Two-Phase Closed Thermosyphon (Wickless Heat Pipe) Including Direct Flow Observation.  

National Technical Information Service (NTIS)

In Part I a visual study of an annular two-phase closed thermosyphon (wickless heat pipe) is reported. The heat transfer surface was stainless steel. Working fluids were Freon-113, ethanol, and water. Photographs of pertinent phenomena are included. The v...

F. E. Andros L. W. Florschuetz

1980-01-01

85

A DIGITAL COMPUTER ANALYSIS OF CLOSED CYCLE WATER NICLEAR POWER PLANT START UP USING NATURAL CIRCULATION. (THERMOSYPHON CODE). VOLUME II  

Microsoft Academic Search

Input data forms, FORTRAN source program listings, and output data sheet ; samples are presented for the Thermo-Syphon code which analyzes the closed-cycle ; water nuclear power plant startup using natural circulation. The code is ; analyzed on an IBM 7090 digital computer. (N.W.R.);

A. N. Nahavandi; B. H. Axelson; G. B. Killinger; A. H. Killinger

1962-01-01

86

Design and testing of thermosyphon batch targets for production of fluorine-18  

NASA Astrophysics Data System (ADS)

18F is a short-lived radioisotope commonly used in Positron Emission Tomography (PET). This radionuclide is typically produced through the 18O(p,n)18 F reaction by proton bombardment of 18O-enriched water. Thermosyphon batch targets have been proposed as a means to increase 18F production due to their enhanced heat rejection capabilities. These boiling targets have been operated with up to 3.2 kW of beam power with manageable 18O enriched water volumes. The primary purpose of this work has been to develop a fundamental approach to target design from a modeling perspective, and to implement this approach to design new thermosyphon targets with enhanced production capabilities. Computational methods have been developed to predict target thermal performance and have been validated with experimental test data from the Duke University Medical Cyclotron and the Wisconsin Medical Cyclotron. These methods have been used to design a new production target for the Duke cyclotron with enhanced 18F production capabilities. Low volume test targets have been successfully operated at the Wisconsin cyclotron with beam powers in excess of the desired 1.6 kW.

Peeples, Johanna Louise

87

A Thermosyphon Titanium-Water Heat Pipe Design for a Lunar Surface Power System  

SciTech Connect

A long titanium-water thermosyphon heat pipe was designed and tested in support of NASA's lunar surface power system. With a {delta}T of 11.6 C, a prototype has been shown to meet the temperature drop specification of 15 C at 400 W and 400 K. The heat pipe is designed to be embedded in a composite radiator panel to spread waste heat delivered by a circulating pumped loop. The major challenge was managing the fluid inventory to balance the conflicting requirements of power capacity and freeze-thaw tolerance. A unique hybrid wick was designed to achieve the required thermal performance and yet store all the working fluid during idle periods in a freeze-thaw tolerant fashion. A non-condensable gas charge was used to boost power capacity at lower operating temperatures. Eighteen prototypes will be built and tested.

Thayer, John; Semenov, Sergey [Thermacore Inc. 780 Eden Road Lancaster, PA 17601 (United States)

2009-03-16

88

A Thermosyphon Titanium-Water Heat Pipe Design for a Lunar Surface Power System  

NASA Astrophysics Data System (ADS)

A long titanium-water thermosyphon heat pipe was designed and tested in support of NASA's lunar surface power system. With a ?T of 11.6 C, a prototype has been shown to meet the temperature drop specification of 15 C at 400 W and 400 K. The heat pipe is designed to be embedded in a composite radiator panel to spread waste heat delivered by a circulating pumped loop. The major challenge was managing the fluid inventory to balance the conflicting requirements of power capacity and freeze-thaw tolerance. A unique hybrid wick was designed to achieve the required thermal performance and yet store all the working fluid during idle periods in a freeze-thaw tolerant fashion. A non-condensable gas charge was used to boost power capacity at lower operating temperatures. Eighteen prototypes will be built and tested.

Thayer, John; Semenov, Sergey

2009-03-01

89

Electrical capacitance tomography measurement of flow patterns and film thickness in a thermosyphon  

NASA Astrophysics Data System (ADS)

An experimental study was performed to evaluate the suitability of using an electrical capacitance tomography (ECT) system to visualize the flow patterns, and to measure the film thickness of the annular flow in a two-phase closed thermosyphon (TPCT). The performance of the ECT system was examined over a range of flow conditions. The experimental data were compared with the visual observations and existing correlations. Results indicated that the ECT system, with the linear back projection (LBP) algorithm, could be used to give an on-line qualitative image of the flow patterns. The Landweber iteration algorithm with optimal step length was implemented off-line to reconstruct high-resolution images. Then, the images were analyzed to obtain the film thickness of the annular flow. The experimental data compared well with the Nusselt’s equation in low vapor velocity range, but showed an increasing deficiency with the increase of vapor velocity.

Li, Jingtao; Chen, Qi; Dong, Xiangyuan; Liu, Shi

2005-03-01

90

Applicability of uniform heat flux Nusselt number correlations to thermosyphon heat exchangers for solar water heaters  

SciTech Connect

Nusselt numbers are measured in three counterflow tube-in-shell heat exchangers with flow rates and temperatures representative of thermosyphon operation in solar water heating systems. Mixed convection heat transfer correlations for these tube-in-shell heat exchangers were previously developed in Dahl and Davidson (1998) from data obtained in carefully controlled experiments with uniform heat flux at the tube walls. The data presented in this paper confirm that the uniform heat flux correlations apply under more realistic conditions. Water flows in the shell and 50 percent ethylene glycol circulates in the tubes. Actual Nusselt numbers are within 15 percent of the values predicted for a constant heat flux boundary condition. The data reconfirm the importance of mixed convection in determining heat transfer rates. Under most operating conditions, natural convection heat transfer accounts for more than half of the total heat transfer rate.

Dahl, S.; Davidson, J. [Univ. of Minnesota, Minneapolis, MN (United States). Mechanical Engineering Dept.

1999-05-01

91

Mixed convection heat transfer and pressure drop correlations for tube-in-shell thermosyphon heat exchangers with uniform heat flux  

SciTech Connect

An important issue arising from prior studies of thermosyphon heat exchangers for use in solar water heaters is the need for heat transfer and pressure drop correlations for the laminar, mixed-convection regime in which these many of these heat exchangers operate. In this paper, the authors present empirical correlations for tube-in-shell heat exchangers with the thermosyphon flow on the shell side. The correlations are determined for uniform heat flux on the tube walls. Ranges of Reynolds and Grashof numbers are 130 to 2,000 and 4 {times} 10{sup 5} to 8 {times} 10{sup 7}, respectively. Nusselt number correlations are presented in a form that combines the contributions of forced and natural convection. Mixed convection dominates forced convection heat transfer in these geometries. Pressure drop is not significantly affected by mixed convection.

Dahl, S.D.; Davidson, J.H. [Univ. of Minnesota, Minneapolis, MN (United States). Mechanical Engineering Dept.

1998-11-01

92

On the performance of a desorber for absorption heat pumps with a thermosyphon and a surface-flame burner  

Microsoft Academic Search

Experiments were carried out to study the operation characteristics of a desorber for a lithium bromide (LiBr)-water absorption heat pump. In order to reduce the size and enhance the thermal efficiency of air-cooled absorption heat pump, a thermosyphon and a surface-flame burner were used. The generation rate of refrigerant, circulation rate of solution and concentration difference in LiBr solution were

Jongsoo Jurng; Chan Woo Park

1998-01-01

93

Economical and Technical Viability of a Thermosyphon Solar Water Heater in Cote D` Ivoire  

NASA Astrophysics Data System (ADS)

We propose a comparative study between solar water heater energy and classical sources of domestic hot water production. This study shows that Solar Water Heater (SWH) could be more competitive if the purchase price was reduced. In order to strengthen local technical capacity, to accelerate dissemination and insure appropriation of SWH technology as well as to stimulate acceptance of other solar technologies in Cote d`Ivoire, we propose an innovated design of a thermosyphon solar water heater, using available local materials in order to reduce cost. A prototype of the study SWH has been built and tested experimentally. The results show that the system is suitable for application in Cote d`Ivoire weather conditions. All those performances, combined with manufacturing simplicity and the absence of moving parts, make the system an interesting technological solution. The results can then be used for the dissemination of the system. The economic study confirms the viability and the real potential market of the locally manufactured SWH. The purchase cost is 2.0 times lower than the imported ones.

Sako, M. K.; N`Guessan, Y.; Andoh, H. Y.; Koffi, P. M. E.; Gbaha, P.; Sangare, M. K.

94

Determination of the dispersion constant in a constrained vapor bubble thermosyphon  

NASA Astrophysics Data System (ADS)

The isothermal profiles of the extended meniscus in a quartz cuvette were measured in a gravitational field using an image analyzing interferometer which is based on computer enhanced video microscopy of the naturally occurring interference fringes. The experimental results for heptane and pentane menisci were analyzed using the extended Young Laplace Equation. These isothermal results characterized the interfacial force field in-siru at the start of the heat transfer experiments by quantifying the dispersion constant, which is a function of the liquid-solid system and cleaning procedures. The experimentally obtained values of the disjoining pressure and the dispersion constants were compared to that predicted from the DLP theory and good agreements were obtained. The measurements are critical to the subsequent non-isothermal experiments because one of the major variables in the heat sink capability of the Constrained Vapor Bubble Thermosyphon, CVBT, is the dispersion constant. In all previous studies of micro heat pipes the value of the dispersion constant has been 'estimated'. One of the major advantages of the current glass cell is the ability to view the extended meniscus at all times. Experimentally, we find that the extended Young-Laplace Equation is an excellent model for the force field at the solid-liquid-vapor interfaces.

Dasgupta, Sunando; Plawsky, Joel L.; Wayner, Peter C., Jr.

1995-01-01

95

Improving thermosyphon solar domestic hot water system model performance. Final report, March 1994--February 1995  

SciTech Connect

Data from an indoor solar simulator experimental performance test is used to develop a systematic calibration procedure for a computer model of a thermosyphoning, solar domestic hot water heating system with a tank-in-tank heat exchanger. Calibration is performed using an indoor test with a simulated solar collector to adjust heat transfer in the heat exchanger and heat transfer between adjacent layers of water in the storage tank. An outdoor test is used to calibrate the calculation of the friction drop in the closed collector loop. Additional indoor data with forced flow in the annulus of the heat exchanger leads to improved heat transfer correlations for the inside and outside regions of the tank-in-tank heat exchanger. The calibrated simulation model is compared to several additional outdoor tests both with and without auxiliary heating. Integrated draw energies are predicted with greater accuracy and draw temperature profiles match experimental results to a better degree. Auxiliary energy input predictions improve significantly. 63 figs., 29 tabs.

Swift, T.N.

1996-09-01

96

Prediction of temperature performance of a two-phase closed thermosyphon using Artificial Neural Network  

NASA Astrophysics Data System (ADS)

Here, the temperature performance of a two-phase closed thermosyphon (TPCT) was investigated using two synthesized nanofluids, including carbon nano-tube (CNT)/water and CNT-Ag/water. In order to determine the temperature performance of a TPCT, the experiments were performed for various values of weight fraction and input power. To predict the other experimental conditions, a reliable and accurate tool should be applied. Therefore Artificial Neural Network (ANN) was applied to predict the process performance. Using ANN, the operating parameters, including distribution of wall temperature (T) and the temperature difference between the input and the output water streams of condenser section (?T) were determined. To achieve this goal, the multi-layer perceptron network was employed. The Levenberg-Marquardt algorithm was chosen as learning algorithm of this network. The results of simulation showed an excellent agreement with the data resulted from the experiments. Therefore it is possible to say that ANN is a powerful tool to predict the performance of different processes.

Shanbedi, Mehdi; Jafari, Dariush; Amiri, Ahmad; Heris, Saeed Zeinali; Baniadam, Majid

2013-01-01

97

Enhancement of heat transport in thermosyphon air preheater at high temperature with binary working fluid: A case study of TEG–water  

Microsoft Academic Search

In this research, the critical heat flux (CHF) due to flooding limit of thermosyphon heat pipe using triethylene glycol (TEG)–water mixture has been investigated. From the experiment it is found that, use of TEG–water mixture can extend the heat transport limitation compared with pure water and higher heat transfer is obtained compared with pure TEG at high temperature applications. Moreover

A. Nuntaphan; J. Tiansuwan; T. Kiatsiriroat

2002-01-01

98

Operation envelope and performance analyses of closed two-phase thermosyphons  

NASA Astrophysics Data System (ADS)

Closed two-phase thermosyphons (CTPTs) are highly reliable and efficient energy transport devices, which are being considered for many industrial applications, such as cooling of electronics, gas-gas and gas-liquid heat exchangers. In this work, an integrated CTPT model was developed to predict the nominal performance as well as the operation limits of the CTPTs. This model also predicts the counter current flooding limit (CCFL) and, the liquid film dry out in the evaporator section, as well as the operation envelope of CTPT. The development of this model was guided by continuous benchmarking with available experimental data. The heat transfer regimes in the liquid pool and liquid film regions in the evaporator section are characterized and appropriate correlation for each regime was developed based on an extensive database of numerous investigators. The developed correlations for the different heat transfer regimes in both the liquid film and liquid pool region were within +/-15% of most of the data. The developed analytical model to predict the counter current flooding limit (CCFL) in CTPTs, treated the shear stress at the liquid-vapor interface as the sum of two terms: (a) adiabatic shear stress, and (b) dynamic shear stress. The model predictions were in good agreement to within +/-10% of the data of other investigators for water and methanol. In order to determine the likelihood for a breakup of the liquid film in the evaporator section of CTPTs, an analytical model was developed to determine the expanding pool height and, hence, the length of the liquid film in the evaporator section. The predictions of this model were within +/-8% of the experimental data. Finally, the integrated CTPT model was used to determine the operation envelope of the CTPT, which is an enclosure with three boundaries. Results showed that increasing the CTPT diameter, evaporator length, or vapor temperature expands the operation envelope, while increasing either the condenser or the adiabatic section length, changes only slightly the envelope's upper and lower boundaries. The results and analyses performed in this research have established that the developed integrated CTPT model is a useful design and performance evaluation tool. (Abstract shortened by UMI.)

Saber, Hamed H.

99

Thermal hydraulic analysis of two-phase closed thermosyphon cooling system for new cold neutron source moderator of Breazeale research reactor at Penn State  

NASA Astrophysics Data System (ADS)

A cold neutron source cooling system is required for the Penn State's next generation cold neutron source facility that can accommodate a variable heat load up to about ˜10W with operating temperature of about 28K. An existing cold neutron source cooling system operating at the University of Texas Cold Neutron Source (TCNS) facility failed to accommodate heat loads upwards of 4W with the moderator temperature reaching a maximum of 44K, which is the critical temperature for the operating fluid neon. The cooling system that was used in the TCNS cooling system was a two-phase closed thermosyphon with a reservoir (TPCTR). The reservoir containing neon gas is kept at room temperature. In this study a detailed thermal analysis of the fundamental operating principles of a TPCTR were carried out. A detailed parametric study of the various geometric and thermo-physical factors that affect the limits of the operational capacity of the TPCTR investigated. A CFD analysis is carried out in order to further refine the heat transfer analysis and understand the flow structure inside the thermosyphon and the two-phase nucleate boiling in the evaporator section of the thermosyphon. In order to help the new design, a variety of ways of increasing the operating range and heat removal capacity of the TPCTR cooling system were analyzed so that it can accommodate the anticipated heat load of 10W or more. It is found, for example, that doubling the pressure of the system will increase the capacity index zeta by 50% for a system with an initial fill ratio FR of 1. A decrease in cryorefrigeration performance angle increases the capacity index. For example taking the current condition of the TCNS system and reducing the angle from the current value of ˜700 by half (˜350) will increase the cooling power 300%. Finally based on detailed analytic and CFD analysis the best operating condition were proposed.

Habte, Melaku

100

Heat transfer performances of a thermosyphon contained non-condensible gas (1)  

NASA Astrophysics Data System (ADS)

The heat transfer performances of the thermosiphon contained non-condensible gas with the working fluid were obtained by an experimental study. The relations among the heat transfer rate, the effectively working length of condenser, the temperature difference between the evaporator and the condenser, and the over-all heat transfer coefficient are described.

Kaneko, K.; Negishi, K.

1985-03-01

101

Experimental measurement and mathematical calculation evaporator temperatures of closed loop thermosyphon  

NASA Astrophysics Data System (ADS)

The closed loop thermoshypon is device operate with working fluid phase change principle. It is a simple and reliable device providing heat transfer. This device utilizes the thermodynamic pressure difference and gravitation to circulate working fluid and has extremely high effective thermal conductivity. Usually is used to cooling of electronic components. The paper describes a design and construction of this device. As a working fluid was used fluorinert FC-72. Next the paper deal with dependences measurement of evaporator temperatures on waste heat of the electronic component and their verification by means of a mathematic calculation based on physical phenomena of boiling, condensation and heat transfer.

Nemec, Patrik; Malcho, Milan; Janda?ka, Jozef

2013-10-01

102

Thermosyphon boiling in vertical channels  

Microsoft Academic Search

The thermal characteristics of ebullient cooling systems for VHSIC and VLSI microelectronic component thermal control are studied by experimentally and analytically investigating boiling heat transfer from a pair of flat, closely spaced, isoflux plates immersed in saturated water. A theoretical model for liquid flow rate through the channel is developed and used as a basis for correlating the rate of

A. Bar-Cohen; H. Schweitzer

1983-01-01

103

Thermosyphon boiling in vertical channels  

NASA Astrophysics Data System (ADS)

The thermal characteristics of ebullient cooling systems for VHSIC and VLSI microelectronic component thermal control are studied by experimentally and analytically investigating boiling heat transfer from a pair of flat, closely spaced, isoflux plates immersed in saturated water. A theoretical model for liquid flow rate through the channel is developed and used as a basis for correlating the rate of heat transfer from the channel walls. Experimental results for wall temperature as a function of axial location, heat flux, and plate spacing are presented. The finding that the wall superheat at constant imposed heat flux decreases as the channel is narrowed is explained with the aid of a boiling thermosiphon analysis which yields the mass flux through the channel.

Bar-Cohen, A.; Schweitzer, H.

104

Study of the Constrained Vapor Bubble Thermosyphon.  

National Technical Information Service (NTIS)

The objective of this effort is to better understand the physics of evaporation, condensation, and fluid flow as they affect the heat transfer processes in a constrained vapor bubble heat exchanger (CVBHX). This CVBHX consists of a small enclosed containe...

P. C. Wayner J. L. Plawsky

2000-01-01

105

Capillary Assisted Thermosyphon For Shipboard Electronics Cooling.  

National Technical Information Service (NTIS)

Recent advances in capillary pumped loop technology were incorporated into the design of a vertical flat plate evaporator for cooling high power electronics aboard naval vessels. This investigation included the design, fabrication, and experimentation of ...

E. H. Larsen

2003-01-01

106

Interfacial force field characterization in a constrained vapor bubble thermosyphon  

Microsoft Academic Search

isothermal profiles of the extended meniscus in a quartz cuvette were measured in the earth`s gravitational field using an image analyzing interferometer that is based on computer-enhanced video microscopy of the naturally occurring interference fringes. These profiles are a function of the stress field. Experimentally, the augmented Young-Laplace equation is an excellent model for the force field at the solid-liquid-vapor

Sunando Dasgupta; Joel L. Plawsky; Peter C. Wayner

1995-01-01

107

ACE and Thermosyphon Design Features Loftus Road Extension Project.  

National Technical Information Service (NTIS)

This report summarizes design parameters and calculations that have been performed for Loftus Road Extension Project. Because of the inclusion of concrete sidewalks, curbs, and gutters, as well as the fact that much of the project is underlain by permafro...

D. J. Goering

2001-01-01

108

Effect of non-condensable gas on the vapor flow in thermosiphons  

NASA Astrophysics Data System (ADS)

A detailed flow field survey was conducted to get a better insight into condensation mechanism of vapor flow onto the cooled plate in the enclosure. A two-dimensional thermosyphon was used as an experimental apparatus and special attention was paid to the effect of non-condensable gas in the thermosiphon. Generally it is understood that the non-condensable gas in the thermosiphon in its steady state operation occupies an upper region of the condensation section, and that there exists an interfacial layer separating vapor flow from non-condensable gas which will move vertically according to the heat input rate applied to the thermosiphon. However the structural properties of this interfacial layer and the boundary layer on the wall of condensation section, such as location of layers, thickness, temperature or density variation across them, have not been thoroughly investigated. A real time laser holographic interferometer was used to visualize a flow field in the thermosiphon. Temperature distribution was measured to evaluate the total heat transfer coefficient in the condensation section.

Matsumoto, T.; Kobayashi, Y.

1985-03-01

109

Black Liquid Solar Collector Demonstrator.  

ERIC Educational Resources Information Center

Describes the details of constructing, and use of, a solar collector. Uses a black liquid to absorb the energy, the thermosyphon effect to drive the liquid through the collector, and a floodlamp as a surrogate sun. (GA)

Weichman, F. L.; Austen, D. J.

1979-01-01

110

Operation of a U-shaped thermosiphon at small angles of inclination  

SciTech Connect

The combined effects of the volume of heat transfer fluid and the angles of inclination of the branches of a thermosyphon on its internal thermal resistance are determined in a parametric analysis for the optimization of the configuration and fluid charge and the thermal efficiency of the thermosyphon. The dependence of the operating temperature gradient on the power input is investigated and the power input optimized on the basis of the results.

Krivonos, V.A.

1988-01-01

111

Use of LHP for cooling power electronic components  

NASA Astrophysics Data System (ADS)

The paper deals with use of cooling equipment build on basis two phase thermosyphon loop. This device belongs to a group of loop heat pipe (LHP). This LHP is a two-phase device with extremely high effective thermal conductivity that utilizes the thermodynamic pressure difference to circulate fluid. It was invented in Russia in the early 1980´s. Thermosyphon loop is similar as LHP but it doesn't contain wick and circulation of the fluid using gravitation force instead of capillary pressure as it is in LHP. The work deals with the cooling insulated gate bipolar transistor with 370 W. The paper describes the course of the heat dissipation using ribbed cooler for natural convection and using fin for forced convection. The results are compared with heat dissipation through thermosyphon loop.

Smitka, M.; Malcho, M.; Nemec, P.; Kolková, Z.

2013-04-01

112

Entrainment or flooding limit in a closed two-phase thermosyphon  

NASA Astrophysics Data System (ADS)

Closed two-phase thermosiphons and gravity-supported heat pipes are highly efficient heat transfer elements which are being increasingly applied in terrestrial heat transport and heat recovery systems, but their performance is limited by various heat transport limitations. In the present paper the entrainment or flooding limit is investigated in more detail. Experiments with a copper-water thermosiphon (2.5 m long, 20 mm outer diameter) have been carried out, the steady-state operation has been studied, and the maximum performance due to flooding has been measured. The influence of liquid fill charge, inclination angle, and operating temperature on the maximum performance has been determined. The experimental results have been assessed and compared with existing theories. Good agreement with the theories of Wallis and Sakhuja has been found.

Nguyen-Chi, H.; Groll, M.

113

Determination of the dispersion constant in a constrained vapor bubble thermosyphon  

Microsoft Academic Search

The isothermal profiles of the extended meniscus in a quartz cuvette were measured in a gravitational field using an image analyzing interferometer which is based on computer enhanced video microscopy of the naturally occurring interference fringes. The experimental results for heptane and pentane menisci were analyzed using the extended Young-Laplace equation. These isothermal results characterized the interfacial force field in-situ

Sunando. Dasgupta; Joel L. Plawsky; Peter C. Wayner Jr.

1993-01-01

114

Determination of the Dispersion Constant in a Constrained Vapor Bubble Thermosyphon.  

National Technical Information Service (NTIS)

The isothermal profiles of the extended meniscus in a quartz cuvette were measured in a gravitational field using an image analyzing interferometer which is based on computer enhanced video microscopy of the naturally occurring interference fringes. The e...

S. Dasgupta J. L. Plawsky P. C. Wayner

1995-01-01

115

Determination of the dispersion constant in a constrained vapor bubble thermosyphon  

NASA Astrophysics Data System (ADS)

The isothermal profiles of the extended meniscus in a quartz cuvette were measured in a gravitational field using an image analyzing interferometer which is based on computer enhanced video microscopy of the naturally occurring interference fringes. The experimental results for heptane and pentane menisci were analyzed using the extended Young-Laplace equation. These isothermal results characterized the interfacial force field in-situ at the start of the heat transfer experiments by quantifying the dispersion constant, which is a function of the liquid-solid system and cleaning procedures. The experimentally obtained values of the disjoining pressure and the dispersion constants were compared to that predicted from the DLP theory and good agreements were obtained. The measurements are critical to the subsequent non-isothermal experiments because one of the major variables in the heat sink capability of the CVBT is the dispersion constant. In all previous studies of micro heat pipes the value of the dispersion constant has been 'guesstimated'. One of the major advantages of the current glass cell is the ability to view the extended meniscus at all times. Experimentally. we find that the extended Young-Laplace equation is an excellent model for the force field at the solid-liquid-vapor interfaces.

Dasgupta, Sunando.; Plawsky, Joel L.; Wayner, Peter C., Jr.

1993-12-01

116

Interfacial force field characterization of a constrained vapor bubble thermosyphon using IAI  

Microsoft Academic Search

The isothermal profiles of the extended meniscus in a quartz cuvette were measured in a gravitational field using IAI (image analyzing interferometer) which is based on computer enhanced video microscopy of the naturally occurring interference fringes. The experimental results for heptane and pentane menisci were analyzed using the extended Young-Laplace Equation. These isothermal results characterized the interfacial force field in-situ

Sunando Dasgupta; Joel L. Plawsky; Peter C. Wayner Jr.

1994-01-01

117

Interfacial force field characterization of a constrained vapor bubble thermosyphon using IAI  

NASA Astrophysics Data System (ADS)

The isothermal profiles of the extended meniscus in a quartz cuvette were measured in a gravitational field using IAI (image analyzing interferometer) which is based on computer enhanced video microscopy of the naturally occurring interference fringes. The experimental results for heptane and pentane menisci were analyzed using the extended Young-Laplace Equation. These isothermal results characterized the interfacial force field in-situ at the start of the heat transfer experiments by quantifying the dispersion constant for the specific liquid-solid system. The experimentally obtained values of the disjoining pressures and the dispersion constants are compared to the subsequent non-isothermal experiments because one of the major variables in the heat sink capability of the CVBT is the dispersion constant. In all previous studies of micro heat pipes the value of the dispersion constant has been 'guesstimated'. The major advantages of the current glass cell is the ability to view the extended meniscus at all times. Experimentally, we find that the extended Young-Laplace Equation is an excellent model for for the force field at the solid-liquid vapor interfaces.

Dasgupta, Sunando; Plawsky, Joel L.; Wayner, Peter C., Jr.

1994-08-01

118

Determination of the dispersion constant in a constrained vapor bubble thermosyphon  

Microsoft Academic Search

The isothermal profiles of the extended meniscus in a quartz cuvette were measured in a gravitational field using an image analyzing interferometer which is based on computer enhanced video microscopy of the naturally occurring interference fringes. The experimental results for heptane and pentane menisci were analyzed using the extended Young Laplace Equation. These isothermal results characterized the interfacial force field

Sunando Dasgupta; Joel L. Plawsky; Peter C. Wayner Jr.

1995-01-01

119

Theoretical Design of Thermosyphon for Process Heat Transfer from NGNP to Hydrogen Plant.  

National Technical Information Service (NTIS)

The Next Generation Nuclear Plant (NGNP) will most likely produce electricity and process heat, with both being considered for hydrogen production. To capture nuclear process heat, and transport it to a distant industrial facility requires a high temperat...

F. Gunnerson M. Patterson P. Sabharwall

2008-01-01

120

Parametric study of pool boiling from porous graphite foams in dielectric liquids  

Microsoft Academic Search

An experimental investigation of pool boiling on porous graphite foams is presented in this paper. A compact thermosyphon was developed to conduct the experiments using different types of graphite foams as evaporator inserts. Two dielectric liquids viz. FC-12 and HFE-700 were used as phase change coolants to investigate the effects of pore diameter and thermal conductivity of the foams on

Liwen Jin; P. Indro; Kai Choong Leong; J. C. Chai

2010-01-01

121

Life cycle environmental impact of a thermosyphonic domestic solar hot water system in comparison with electrical and gas water heating  

Microsoft Academic Search

A methodology for the environmental impact evaluation over the life span of a Domestic Solar Hot Water System (DSHWS) is presented. The results are compared to the environmental consequences of the conventional energy form substituted and the total environmental gain is calculated. For the purposes of this analysis, the “Eco-indicator ’99” Life Cycle Impact Assessment methodology was adopted and the

G. Tsilingiridis; G. Martinopoulos; N. Kyriakis

2004-01-01

122

A DIGITAL COMPUTER ANALYSIS OF CLOSED CYCLE WATER NUCLEAR POWER PLANT START UP USING NATURAL CIRCULATION (THERMOSYPHON CODE). VOLUME I  

Microsoft Academic Search

An analysis of the natural circulation in the primary system of a closed ; cycle water nuclear power plant during plant start up is presented. The solution ; to the problem is obtained by numerical integratfon of the governing differential ; equations, using an IBM-7090 digital computer. The thermodynamic behavior of the ; primary system coolant during plant startup with

A. N. Nahavandi; B. H. Axelson; G. B. Killinger; A. H. Killinger

1962-01-01

123

The threshold value of heat flux for thermosyphon microfilm heat transfer with the testing sample partially immersed in liquid nitrogen  

NASA Astrophysics Data System (ADS)

To simulate the performance of condenser-boiler in an air separation plant, the boiling section formed by 1m long plate-fin narrow channel is only partially immersed in liquid nitrogen. When the heating power supplied to whole section of the testing sample is maintained constant the boiling temperature difference is increased by 0.19K only with reduction in immersion depth of 40cm. It is concluded that the condenser-boiler will be operated in a safe condition even when the immersion reduced by 40% as long as the heat flux is maintained above a threshold value.

Yuyuan, Wu; Shouyun, Peng; Liufang, Chen; Hongqi, Xie

124

Simulation of natural convection in a rectangular loop using finite elements  

SciTech Connect

A two-dimensional finite-element analysis of natural convection in a rectangular loop is presented. A psi-omega formulation of the Boussinesque approximation to the Navier-Stokes equation is solved by the false transient technique. Streamlines and isotherms at Ra = 10/sup 4/ are shown for three different modes of heating. The results indicate that corner effects should be considered when modeling flow patterns in thermosyphons.

Pepper, D W; Hamm, L L; Kehoe, A B

1984-01-01

125

Advertising Effects and Effectiveness  

Microsoft Academic Search

The results of the application of an integrated econometric time-series model for advertising effectiveness is presented. The model form gives rise to three possible advertising effects: brand loyalty, current effects (both simple and compound) and carryover effects. The inherent nature of these effects is related to the degree of involvement and the affective or cognitive aspects of the purchase decision.

Mike T. Bendixen

1993-01-01

126

Natural convection heat exchangers for solar water heating systems. Technical progress report, September 15, 1996--November 14, 1996  

SciTech Connect

The goals of this project are: (1) to develop guidelines for the design and use of thermosyphon side-arm heat exchangers in solar domestic water heating systems, and (2) to establish appropriate modeling and testing criteria for evaluating the performance of systems using this type of heat exchanger. The tasks for the project are as follows: (1) Develop a model of the thermal performance of thermosyphon heat exchangers in solar water heating applications. A test protocol will be developed which minimizes the number of tests required to adequately account for mixed convection effects. The TRNSYS component model will be fully integrated in a system component model and will use data acquired with the specified test protocol. (2) Conduct a fundamental study to establish friction and heat transfer correlations for conditions and geometries typical of thermosyphon heat exchangers in solar systems. Data will be obtained as a function of a buoyancy parameter based on Grashof and Reynolds numbers. The experimental domain will encompass the ranges expected in solar water heating systems.

Davidson, J.H.

1998-06-01

127

Natural convection heat exchangers for solar water heating systems. Technical progress report, August 1, 1995--September 30, 1995  

SciTech Connect

The goals of this project are: (1) to develop guidelines for the design and use of thermosyphon side-arm heat exchangers in solar domestic water heating systems, and (2) to establish appropriate modeling and testing criteria for evaluating the performance of systems using this type of heat exchanger. The tasks for the project are as follows: (1) Develop a model of the thermal performance of thermosyphon heat exchangers in solar water heating applications. A test protocol will be developed which minimizes the number of tests required to adequately account for mixed convection effects. The TRNSYS component model will be fully integrated in a system component model and will use data acquired with the specified test protocol. (2) Conduct a fundamental study to establish friction and heat transfer correlations for conditions and geometries typical of thermosyphon heat exchangers in solar systems. Data will be obtained as a function of a buoyancy parameter based on Grashof and Reynolds numbers. The experimental domain will encompass the ranges expected in solar water heating systems.

Davidson, J.H.

1998-06-01

128

Natural convection heat exchangers for solar water heating systems. Technical progress report, December 31, 1995--January 31, 1996  

SciTech Connect

The goals of this project are: (1) to develop guidelines for the design and use of thermosyphon side-arm heat exchangers in solar domestic water heating systems, and (2) to establish appropriate modeling and testing criteria for evaluating the performance of systems using this type of heat exchanger. The tasks for the project are as follows: (1) Develop a model of the thermal performance of thermosyphon heat exchangers in solar water heating applications. A test protocol will be developed which minimizes the number of tests required to adequately account for mixed convection effects. The TRNSYS component model will be fully integrated in a system component model and will use data acquired with the specified test protocol. (2) Conduct a fundamental study to establish friction and heat transfer correlations for conditions and geometries typical of thermosyphon heat exchangers in solar systems. Data will be obtained as a function of a buoyancy parameter based on Grashof and Reynolds numbers. The experimental domain will encompass the ranges expected in solar water heating systems.

Davidson, J.H.

1998-06-01

129

Doppler Effect  

NSDL National Science Digital Library

Doppler effect followed from water waves to sound waves to light waves. Red shift of the universe is also explored. What is doppler effect? It is the change in frequency of a wave for an observer moving relative to the source of the wave. What does that mean? Watch this: moving doppler effect video What does the doppler effect look like in a stationary and moving object? dooppler effect views What does doppler effect have to do with stars and galaxies??? View the following ...

Clemons, Mrs.

2010-11-10

130

Doppler Effect  

NSDL National Science Digital Library

Doppler effect followed from water waves to sound waves to light waves. Red shift of the universe is also explored. What is doppler effect? It is the change in frequency of a wave for an observer moving relative to the source of the wave. What does that mean? Watch this: moving doppler effect video What does the doppler effect look like in a stationary and moving object? dooppler effect views What does doppler effect have to do with stars and galaxies??? View the following ...

Brown, Mrs.

2010-10-26

131

Greenhouse Effect  

NSDL National Science Digital Library

This activity is a greenhouse-effect-in-a-bottle experiment. The lesson includes readings from NEED.org and an inquiry lab measuring the effect of carbon dioxide and temperature change in an enclosed environment.

Education, Connecticut E.

132

Chemotherapy Effects  

MedlinePLUS

... saved articles window. My Saved Articles » My ACS » Chemotherapy Effects Chemotherapy drugs are powerful medicines that can cause side ... on the side effects most commonly caused by chemotherapy, this is a good place to start. Managing ...

133

Effects of \\  

Microsoft Academic Search

Brainstorming instruction is an effective method for increasing the production of good ideas in a particular type of creative thinking problems, and is even more effective if preceded by extensive training in its use. (5 tables)

Sidney J. Parnes; Arnold Meadow

1959-01-01

134

Research and development of long heat pipes and their applications  

NASA Astrophysics Data System (ADS)

A 40 m thermosyphon type flexible corrugated heat pipe was constructed and its heat transfer characteristics were measured. The flooding phenomenon was quantitatively observed using electronic stethoscopes, and its influence to the heat transfer characteristics was determined. The particular features of the road heating system using long heat pipes are: (1) there is no possibility of water leaking and their maintenance is easy; (2) they endure heavy loads, thermal stresses, vibrations and ground subsidence; (3) the heat transfering surface area of the heat pipes is so large that it is particularly effective for heating through small temperature difference; and (4) the installation is easy and inexpensive.

Takaoka, M.; Mohtai, T.; Mochizuki, M.; Mashiko, K.

1984-03-01

135

Thermal effects  

SciTech Connect

Literature dealing with the following topics was reviewed: effects of power plant once-through cooling on aquatic systems; site studies; producers - effects on growth and production; consumers; decomposers; diseases and parasites; and beneficial uses of power plant condenser cooling water. (DAD)

Talmage, S.S.; Coutant, C.C.

1980-06-01

136

Thermal effects  

Microsoft Academic Search

Literature dealing with the following topics was reviewed: effects of power plant once-through cooling on aquatic systems; site studies; producers - effects on growth and production; consumers; decomposers; diseases and parasites; and beneficial uses of power plant condenser cooling water. (DAD)

S. S. Talmage; C. C. Coutant

1980-01-01

137

Naloxone: Effects and Side Effects  

Center for Drug Evaluation (CDER)

Text Version... Cardiovascular effects ?Hypertension morbidity (eg, vascular aneurysms) ... Hypertension morbidity (eg, vascular aneurysms) ... More results from www.fda.gov/downloads/drugs/newsevents

138

Thermal effects  

Microsoft Academic Search

Literature concerning the effects of temperature on aquatic organisms is reviewed. Subjects include: site studies, producers, consumers, decomposers, diseases and parasites, and beneficial uses. Specific topics involve growth, reproduction, temperature tolerance, preferred temperature, feeding, distribution, oxygen metabolism, and morphology.

1976-01-01

139

Position Effects  

Microsoft Academic Search

Position effects describe the observed alteration in protein-coding gene expression that may accompany a change in genomic\\u000a position of a given gene. A position effect may result from chromosomal translocation or other genomic rearrangements. Recent\\u000a advances in chromatin studies in several different species including yeast, Drosophila, and mouse have contributed significantly\\u000a to better understanding of human diseases resulting from abnormal

Pawel Stankiewicz

140

Interpersonal Effectiveness  

NSDL National Science Digital Library

Interpersonal Effectiveness provides participants with an opportunity to develop their interpersonal skills through interactive exercises conducted in a team setting. Debriefing these exercises with all members of the class helps ensure that the exercises translate into personal and interpersonal learning for the participants. After completing this module, students should be able to identify the principles of good teamwork and effective communication and demonstrate those skills during a series of interactive exercises. Note: This module is part of a modularized manufacturing technology curriculum created by the PSCME, found at www.pscme.org/educators.html.

Alston, Michele; King, John

2010-07-26

141

Photoelectric Effect  

NSDL National Science Digital Library

This is a series of simulations of aspects of the photoelectric effect. There is an animation of the experiment with four choices of incident radiation - low and high intensity "red", to represent low energy light and low and high intensity "blue" to represent higher energy light. Electron production is animated and there is an ammeter to simulate current flow. Additional simulations show the effect of light frequency and intensity. There is a link to a spreadsheet that allows students to choose a sample from among five metals. The spreadsheet includes several questions to be answered after working through the materials.

142

Coriolis Effect  

NSDL National Science Digital Library

This set of four animated slides illustrates the Coriolis effect, a manifestation of one of Newton's laws which says that objects move in a straight line, in an "inertial" frame of reference, unless acted upon by a force. The slides use the analogy of a ball thrown on a rotating carousel.

143

Thermal effects  

Microsoft Academic Search

The 1976 literature on thermal effects was reviewed under the following categories: reviews; power plant studies; producers; consumer reproduction, development, morphology, distribution, thermal tolerance, growth, feeding, activity, oxygen metabolism, temperature and other stresses; decomposers; diseases and parasites and beneficial uses. Many of the studies are summarized in tabular form.

C. C. Coutant; S. S. Talmadge

1977-01-01

144

Slingshot Effect  

NSDL National Science Digital Library

This web page demonstrates the slingshot effect through a Flash simulation. The user places an object at some distance from Jupiter, sets up its initial velocity, then choose the appropriate time to lunch it. Once the simulation begins, the path of the projectile and its speed are shown.

Fowler, Michael; Ching, Jacquie H.

2008-09-20

145

Atmospheric Effect  

Microsoft Academic Search

AN atmospheric effect, which is sometimes observed in England, displayed itself here in great beauty yesterday. The western sun had been cut off from us by an intervening ridge, while the upper atmosphere was still filled with his light. There was a good deal of opalescent haze in the atmosphere, which, had the sun shone upon it uniformly, would have

John Tyndall

1872-01-01

146

Sleeper Effects  

ERIC Educational Resources Information Center

|Early experience preserves and refines many capabilities that emerge prenatally. Here we describe another role that it plays--establishing the neural substrate for capabilities that emerge at a much later point in development. The evidence comes from sleeper effects: permanent deficits when early experience was absent in capabilities that…

Maurer, Daphne; Mondloch, Catherine J.; Lewis, Terri L.

2007-01-01

147

Greenhouse Effect  

NSDL National Science Digital Library

This HyperPhysics webpage contains information and diagrams on global warming, the greenhouse effect, and greenhouse gases. Numerous graphs and diagrams illustrate the measurements and concepts. Also, this page displays the famous "Keeling curve" showing atmospheric carbon dioxide concentration versus time from 1958 to 2004. This page page is part of the HyperPhysics Collection, which contains many short, illustrated pages on various areas of physics and astronomy.

Nave, Carl R.

2013-04-29

148

Effective Presentations  

PubMed Central

Where the purpose of presentations is to inform, effective delivery is important to ensure that audiences receive the educational message. We offer six suggestions: introduce the topic in an interesting way; speak loudly enough; do not read; involve the audience actively; respect the attention span of the audience; and limit the amount of content. We conclude that the skills of live public presentation can be learned, but that the art of presentation is innate. Imagesp2063-ap2064-a

Spooner, H. James; Swanson, Richard W.

1990-01-01

149

Piezoelectric Effect  

NSDL National Science Digital Library

In this activity, by the Concord Consortium's Molecular Literacy project, students explore the piezoelectric effect, which is the conversion between electricity and mechanical motion. The model used in this activity shows this conversion and users can manipulate the model to change the voltage and observe changes to a crystal. The activity itself is a java-based interactive resource built upon the free, open source Molecular Workbench software. In these activities, students are allowed to explore at their own pace in a digital environment full of demonstrations, illustrations, and models they can manipulate. In addition to the activity, visitors will find an overview of the activity and central and key concepts.

2008-10-23

150

Design and Performance of a Hybrid PV/T Solar Water Heater  

NASA Astrophysics Data System (ADS)

In this paper we present design considerations and experimental results of a thermosyphonic hybrid PV/T solar system that is investigated at the University of Patras. Hybrid PV/T systems can provide electrical and thermal energy, thus achieving a higher energy conversion rate of the absorbed solar radiation. We tested outdoors PV/T prototypes consisted of pc-Si PV modules and heat exchanger of copper sheet with copper pipes, for two system types (PVT/UNGL and PVT/GL). We used commercial PV modules, which give about 12%-15% efficiency, depending on the operating temperature and the use or not of additional glazing. During the experiments the generated electricity was transmitted to a load, simulating real system operation. Steady state tests of the system were performed outdoors to determine collector thermal efficiency. The glazed PV/T collector presents remarkably higher thermal output than the unglazed PV/T collector, but the electrical output of it is reduced due to additional optical losses. The experimental study of the tested thermosyphonic hybrid PV/T solar device showed that it can perform effectively during all year long, achieving at least 40° C of hot water and producing electricity at a satisfactory level.

Tripanagnostopoulos, Y.; Souliotis, M.; Makris, Th.; Georgostathis, P.; Sarris, M.

2010-01-01

151

Radiation effects.  

PubMed

International Commission on Radiological Protection (ICRP) Committee 1 (C1) considers the risk of induction of cancer and heritable disease; the underlying mechanisms of radiation action; and the risks, severity, and mechanisms of induction of tissue reactions (formerly 'deterministic effects'). C1 relies upon the interpretation of current knowledge of radio-epidemiological studies; current information on the underlying mechanisms of diseases and radiation-induced disease; and current radiobiological studies at the whole animal, tissue, cell, and molecular levels. This overview will describe the activities of C1 in the context of the 2007 Recommendations of ICRP. In particular, the conclusions from the most recent C1 Task Group deliberations on radon and lung cancer, and tissue reactions will be discussed. Other activities are described in summary fashion to illustrate those areas that C1 judge to be likely to influence the development of the risk estimates and nominal risk coefficients used for radiation protection purposes. PMID:23088999

Preston, R J

2012-08-22

152

Side Effects of Chemotherapy  

MedlinePLUS

... Men Living with Prostate Cancer Side Effects of Chemotherapy Side Effects Urinary Dysfunction Bowel Dysfunction Erectile Dysfunction ... Side Effects of Hormone Therapy Side Effects of Chemotherapy Side Effects: When to Seek Help PSA Rising ...

153

Effective Teaching/Effective Urban Teaching  

ERIC Educational Resources Information Center

|This article considers the ways in which 17 novice teachers define and describe effective urban teaching and the stark contrasts that these teachers draw between effective urban teaching and effective teaching. The authors find that descriptions of students played a considerable role when participants made distinctions between effective teaching…

Watson, Dyan; Charner-Laird, Megin; Kirkpatrick, Cheryl L.; Szczesiul, Stacy Agee; Gordon, Pamela J.

2006-01-01

154

Natural convection heat exchangers for solar water heating systems. Technical progress report, February 1, 1996--March 31, 1996.  

National Technical Information Service (NTIS)

This progress report describes the thermodynamic testing and modeling of a thermosyphon heat exchanger used in solar water heating systems. Testing of a four tube-in-shell thermosyphon heat exchanger was performed in two parts. The first portion of the te...

J. H. Davidson

1998-01-01

155

The Ranschburg effect  

Microsoft Academic Search

Summarizes recent research on the Ranschburg effect, an inhibitory effect on short-term recall observed when a stimulus string contains a repeated element, and attempts to identify the conditions associated with the effect. The theoretical bases for the Ranschburg effect, including a new analysis of the effect are considered and the results of 2 experiments designed as a 1st test of

John C. Jahnke

1969-01-01

156

Mercury: Health Effects  

MedlinePLUS

... toxicological profile for mercury . Top of page Elemental mercury effects Elemental (metallic) mercury primarily causes health effects ... 0370.htm . Top of page Effects of other mercury compounds (inorganic and organic) High exposures to inorganic ...

157

On Effect Size  

ERIC Educational Resources Information Center

|The call for researchers to report and interpret effect sizes and their corresponding confidence intervals has never been stronger. However, there is confusion in the literature on the definition of effect size, and consequently the term is used inconsistently. We propose a definition for effect size, discuss 3 facets of effect size (dimension,…

Kelley, Ken; Preacher, Kristopher J.

2012-01-01

158

Effect Lines for Specifying Animation Effects  

Microsoft Academic Search

Abstract When we create 2D animations on a desktop computer using programs such as Microsoft PowerPoint or Macrome- dia Flash, we assign effects to objects and define their pa- rameters, such as their path, speed, and time of movement. To do this, we use conventional interfaces like menus or dia- log boxes. However, the motion effects associated with each object

Yoshikazu Kato; Etsuya Shibayama; Shin Takahashi

2004-01-01

159

Regulation with placebo effects.  

PubMed

A growing scientific literature supports the existence of placebo effects from a wide range of health interventions and for a range of medical conditions. This Article reviews this literature, examines the implications for law and policy, and suggests future areas for research on placebo effects. In particular, it makes the case for altering the drug approval process to account for, if not credit, placebo effects. It recommends that evidence of placebo effects be permitted as a defense in cases alleging violations of informed consent or false advertising. Finally, it finds that tort law already has doctrines such as joint and several liability to account for placebo effects. Future research on placebo effects should focus on whether awareness of placebo effects can disable these effects and whether subjects can control their own placebo effects. PMID:19353835

Malani, Anup

2008-12-01

160

Kite Pseudo Effect Algebras  

NASA Astrophysics Data System (ADS)

We define a new class of pseudo effect algebras, called kite pseudo effect algebras, which is connected with partially ordered groups not necessarily with strong unit. In such a case, starting even with an Abelian po-group, we can obtain a noncommutative pseudo effect algebra. We show how such kite pseudo effect algebras are tied with different types of the Riesz Decomposition Properties. Kites are so-called perfect pseudo effect algebras, and we define conditions when kite pseudo effect algebras have the least non-trivial normal ideal.

Dvure?enskij, Anatolij

2013-10-01

161

The Mossbauer Effect.  

National Technical Information Service (NTIS)

The theory of the nuclear Mossbauer effect and its optical analogue is presented. Introductory paragraphs deal with the destruction of resonance fluorescence in case of a freely recoiling nucleus. The partial restoration of resonance by Doppler effect and...

A. Mukerji C. A. Coulter

1966-01-01

162

Stormwater BMP Effectiveness Toolkit  

EPA Science Inventory

US EPA has identified the effectiveness of Stormwater Best Management Practices (BMPs) as a priority research need. Effective protection of biotic integrity requires that processes maintaining the diversity of physical habitats be protected. Methods are needed to evaluate the e...

163

Effects of Stroke  

MedlinePLUS

... Davis Legacy Fund Stay Informed Share » Effects of Stroke After Stroke Effects of Stroke Pediatric Stroke Rehabilitation ... PDF file. Content Updated: August 2012 Get Involved Stroke and You Stroke Survivors Caregivers and Families Healthcare ...

164

The Stimulated Raman Effect.  

National Technical Information Service (NTIS)

The paper reviews the main experimental and theoretical developments in stimulated Raman scattering of light, which has been actively investigated since 1962. The effect cannot be discussed properly without paying attention to related nonlinear effects wh...

N. Bloembergen

1967-01-01

165

Effective Frequency Technique.  

National Technical Information Service (NTIS)

An effective monochromatic frequency technique is described to represent the effects of finite spectral bandwidth for active and passive measurements centered on an absorption line, a trough region, or a slowly varying spectral feature. For Gaussian and r...

C. L. Korb C. Y. Weng

2003-01-01

166

Leadership Effectiveness and Gender.  

National Technical Information Service (NTIS)

This research paper on the subject of Leadership Effectiveness and Gender attempts to conduct a focused amount of research to answer the question about the correlation between gender and leadership effectiveness. It specifically looks at the current defin...

C. R. Gedney

1999-01-01

167

Global Effects Simulation Studies.  

National Technical Information Service (NTIS)

This document reviews the initial rise of a fire plume in the atmosphere, including effects of the condensation of entrained moisture. The condensation, expansion, and evaporation of the water cloud are examined, as are the relative effects of scattering ...

C. Chandler E. Bauer F. A. Albini

1986-01-01

168

Health effects of ozone  

Microsoft Academic Search

The 1989 Critical Review on Health Effects of Ozone by Morton Lippmann is a valuable contribution to the literature on criteria air pollutants. In a comprehensive fashion, the paper methodically examines key areas relevant to understanding effects of ozone on human health: exposure and dosimetry, populations and responses of concern, research approaches, and effects upon specific pulmonary endpoints from single

Utell

1989-01-01

169

Health effects of ozone  

Microsoft Academic Search

Dr. Morton Lippmann prepared, at the request of the A WMA Review Committee, an extensive update of the available information on the biological effects of ozone. His review is a thorough and well-written summary of what is known about respiratory effects of low ozone concentrations. The authors is well qualified to evaluate clinical data on ozone effects since a substantial

Vostal

1989-01-01

170

Special Effects Activity Guide.  

ERIC Educational Resources Information Center

|This guide accompanies "Special Effects," a 40-minute IMAX film and "Special Effects II", a multimedia, interactive traveling exhibit designed by the California Museum of Science and Industry. The exhibit focuses on the underlying scientific and technical processes of special effects from the earliest motion picture to state-of-the-art digital…

Boxer, Jennifer; Valenta, Carol

171

How effective are models?  

Microsoft Academic Search

This article discusses a number of common interpretations of 'implementation' in the literature, and how these have been confused. Various different levels of implementation are then discussed, including the concept of model effectiveness. This is concerned with both the operational effectiveness of the model, as shown by a tangible improvement in the system modelled, and the personal effectiveness in helping

John Fripp

1985-01-01

172

Special Effects Activity Guide.  

ERIC Educational Resources Information Center

This guide accompanies "Special Effects," a 40-minute IMAX film and "Special Effects II", a multimedia, interactive traveling exhibit designed by the California Museum of Science and Industry. The exhibit focuses on the underlying scientific and technical processes of special effects from the earliest motion picture to state-of-the-art digital…

Boxer, Jennifer; Valenta, Carol

173

Irradiation Effects on Zircaloy.  

National Technical Information Service (NTIS)

In a water cooled reactor, the neutron effect on zirconium base alloys which are used in the core, is a twofold one: - indirect effect, by means of modifications to the alloy environment; - direct effect occurence of irradiation defects in the material. T...

P. Morize

1983-01-01

174

LUX Cryogenics and Circulation  

NASA Astrophysics Data System (ADS)

LUX is a new dark matter direct detection experiment being carried out at the Sanford Underground Research Facility, at the renewed Homestake mine in Lead, SD. The detector's large size supports effective internal shielding from natural radioactivity of the surrounding materials and environment. The LUX detector consists of a cylindrical vessel containing 350 kg of liquid xenon (LXe) cooled down and maintained at 175-K operating temperature using a novel cryogenic system. We report the efficiency of our thermosyphon-based cooling system, as well as the efficiency of a unique internal heat exchanger with standard gas phase purification using a heated getter, which allows for very high flow purification without requiring large cooling power. Such systems are required for multi-ton scale up.

Bradley, Adam

2012-10-01

175

LUX0.1 Prototype Results: Cryogenics and Circulation  

NASA Astrophysics Data System (ADS)

LUX is a new dark matter direct detection experiment to be carried out at the Sanford Lab, the renewed underground facility at the Homestake mine in Lead, SD. The detector's large size supports effective internal shielding from natural radioactivity of the surrounding materials and environment. The LUX detector consists of a cylindrical vessel containing 350 kg of liquid xenon (LXe) cooled down using a novel cryogenic system. We tested a small-scale four PMT prototype utilizing over 300 gm of active xenon, installed in the full-sized cryostat. We report the efficiency of a unique internal heat exchanger with standard gas phase purification using a heated getter, which allows for very high flow purification without requiring large cooling power, as well as the efficiency of a thermosyphon-based cooling system. Such systems are required for multi-ton scale up. )

Bradley, Adam

2010-02-01

176

Nonlinear Talbot Effect  

NASA Astrophysics Data System (ADS)

We propose and experimentally demonstrate the nonlinear Talbot effect from nonlinear photonic crystals. The nonlinear Talbot effect results from self-imaging of the generated periodic intensity pattern at the output surface of the crystal. To illustrate the effect, we experimentally observed second-harmonic Talbot self-imaging from 1D and 2D periodically poled LiTaO3 crystals. Both integer and fractional nonlinear Talbot effects were investigated. The observation not only conceptually extends the conventional Talbot effect, but also opens the door for a variety of new applications in imaging technologies.

Zhang, Yong; Wen, Jianming; Zhu, S. N.; Xiao, Min

2010-05-01

177

Nonlinear Talbot effect.  

PubMed

We propose and experimentally demonstrate the nonlinear Talbot effect from nonlinear photonic crystals. The nonlinear Talbot effect results from self-imaging of the generated periodic intensity pattern at the output surface of the crystal. To illustrate the effect, we experimentally observed second-harmonic Talbot self-imaging from 1D and 2D periodically poled LiTaO(3) crystals. Both integer and fractional nonlinear Talbot effects were investigated. The observation not only conceptually extends the conventional Talbot effect, but also opens the door for a variety of new applications in imaging technologies. PMID:20482176

Zhang, Yong; Wen, Jianming; Zhu, S N; Xiao, Min

2010-05-07

178

The butterfly effect of the "butterfly effect".  

PubMed

The "Butterfly Effect" metaphor states with variance that the flap of a butterfly's wings in Brazil can cause a tornado in Texas. This metaphor has become part of the common vernacular of Western culture. In this paper I discuss the origins of the metaphor, examine its current usage within popular culture, and present an argument as to why it is popular. I propose that the metaphor is a type of semantic attractor, a narrative device with invariant meaning but audience-specific contextualization. Finally I address whether the Butterfly Effect metaphor is a good example of itself. PMID:19527619

Dooley, Kevin J

2009-07-01

179

Virality, Network Effects and Advertising Effectiveness  

Microsoft Academic Search

Many video ads are designed to go viral, so that the total number of views they receive depends on customers sharing the ads with their friends. This paper explores the relationship between achieving this endogenous reach and the effectiveness of the ad at persuading a consumer to purchase or adopt a favorable attitude towards a product. The analysis combines data

Catherine Tucker

2011-01-01

180

Coexistence of qubit effects  

Microsoft Academic Search

Two quantum events, represented by positive operators (effects), are coexistent if they can occur as possible outcomes in a single measurement scheme. Equivalently, the corresponding effects are coexistent\\u000a if and only if they are contained in the ranges of a single (joint) observable. Here we give several equivalent characterizations\\u000a of coexistent pairs of qubit effects. We also establish the equivalence

Paul Busch; Heinz-Jürgen Schmidt

2010-01-01

181

Practical and effective ALARA.  

PubMed

The ALARA Principle ensures that the total effective dose equivalent is minimized subject to economic and social factors. Effective ALARA programs must include the participation of all facility workgroups, management support, teamwork, and strong leadership. The development and sustainability of effective ALARA programs require the establishment and monitoring of goals, rewarding the successful achievement of those goals, and incorporating lessons learned from tasks that fail to meet their goals. PMID:20386191

Bevelacqua, Joseph John

2010-05-01

182

Effective Strategies Brief  

NSDL National Science Digital Library

In this research brief the authors detail effective teaching strategies for teaching students with difficulties in math. The brief summarizes the work of over fifty research studies and details the practices that were seen as consistently effective across many of them. The brief details six instructional strategies and presents data describing the effectiveness of each on special education students and low-achieving students. The brief can be viewed on the webpage or downloaded as a PDF.

Gersten, Russell; Clarke, Benjamin S.

2007-01-01

183

Magnetic Casimir effect  

SciTech Connect

The Casimir effect results from alterations of the zero-point electromagnetic energy introduced by boundary conditions. For ferromagnetic layers separated by vacuum (or a dielectric), such boundary conditions are influenced by the magneto-optical Kerr effect. We will show that this gives rise to a long-range magnetic interaction and discuss the effect for two different configurations (magnetization parallel and perpendicular to the layers). Analytical expressions are derived for two models and compared to numerical calculations. Numerical calculations of the effect for Fe are also presented and the possibility of an experimental observation of the Casimir magnetic interaction is discussed.

Metalidis, G.; Bruno, P. [Max-Planck-Institut fuer Mikrostrukturphysik, Weinberg 2, D-06120 Halle (Germany)

2002-12-01

184

The polarized EMC effect  

SciTech Connect

We calculate both the spin independent and spin dependent nuclear structure functions in an effective quark theory. The nucleon is described as a composite quark-diquark state, and the nucleus is treated in the mean field approximation. We predict a sizable polarized EMC effect, which could be confirmed in future experiments.

W. Bentz; I. C. Cloet; A. W. Thomas

2007-02-01

185

Health effects of ozone  

Microsoft Academic Search

The author comments on Morton Lippmann's paper entitled Health Effects of Ozone which was presented at the 82nd Air and Waste Management Association Annual Meeting and Exhibition, held in Anaheim, California in June 1989. Thanks to the efforts of Dr. Lippmann we have a better understanding of the acute, prolonged and chronic exposure health effects of ozone and are in

McKee

1989-01-01

186

Cardiovascular effects of leptin  

Microsoft Academic Search

A wealth of investigations, ranging from clinical and animal model studies to in vitro analyses, have generated great interest in the cardiovascular effects of leptin. Accordingly, many studies have examined the contribution of leptin to cardiac remodeling in heart failure and whether the effects of leptin on metabolism, apoptosis, extracellular matrix remodeling, and hypertrophy could explain the so-called obesity paradox.

Gary Sweeney

2009-01-01

187

The Kaye Effect  

ERIC Educational Resources Information Center

|The International Young Physicists' Tournament (IYPT) is a worldwide, annual competition for secondary school students. This is our solution to problem number 10, "The Kaye effect", as presented in the final round of the 21st IYPT in Trogir, Croatia. The Kaye effect occurs when a thin stream of shampoo or a different adequate non-Newtonian liquid…

Binder, J. M.; Landig, A. J.

2009-01-01

188

The effectiveness of decoupling  

Microsoft Academic Search

This paper examines the effectiveness of decoupling as an optimization technique for high-performance computer architectures. Decoupled access execute architectures are described, and the concept of control decoupling is introduced and justified. A description of a highly-decoupled architecture is given, and a metric for the effectiveness of decoupling on particular programs, the Loss of Decoupling frequency is introduced. Finally, a number

Peter L. Bird; Alasdair Rawsthorne; Nigel P. Topham

1993-01-01

189

Nitrogen oxides - animal effects  

Microsoft Academic Search

The results of animal studies investigating the effects of nitrogen dioxide are reviewed in an attempt to arrive at objective grounds for an NOâ standard. There appears to be no threshold level for NOâ so far as some detectable alteration of lung function or structure in animals is concerned. A threshold may be reached for an effect contributing to clinical

Crocker

1973-01-01

190

Defining Effective Teaching  

ERIC Educational Resources Information Center

|The author looks at the meaning of specific terminology commonly used in student surveys: "effective teaching." The research seeks to determine if there is a difference in how "effective teaching" is defined by those taking student surveys and those interpreting the results. To investigate this difference, a sample group of professors and…

Layne, L.

2012-01-01

191

Theorizing Interactivity's Effects  

Microsoft Academic Search

Noting that interactivity is often defined but seldom theorized in the literature, this article provides some pointers for developing theories about effects of interactivity, particularly as it applies to Web-based mass communication. It first makes the case that interactivity is an attribute of the technology and not that of the user. It exposes the tautology of studying the effects of

S. Shyam Sundar

2004-01-01

192

Effects of Mobile Communication  

Microsoft Academic Search

Before reviewing some of the key consequences of mobile communication technology, a brief discussion of how they fit within the media effects paradigm is in order. At the risk of oversimplification, we understand the media effects paradigm as a framework for understanding how mass media content influences attitudes and behavior of audience members. To be fair, it is important to

Scott W. Campbell

193

Carbon star effective temperatures  

Microsoft Academic Search

Possible methods for measuring the effective temperatures of individual carbon stars are discussed. Since calibrations of broad or narrow-band photometric colors is impractical at present, empirical corrections to narrow band color temperatures is the only valid procedure. The effective temperature of the star TW Oph is estimated, based on preliminary reduction of the occultation and associated photometry

S. T. Ridgway; G. H. Jacoby; R. R. Joyce; D. C. Wells

1981-01-01

194

Institutional Effectiveness Report.  

ERIC Educational Resources Information Center

This is the first edition of the College of the Canyon's (California) Institutional Effectiveness Report, which is modeled after the statewide report prepared by the Chancellor's Office. The college is measuring 60 effectiveness indicators in four mission areas: student access, student success, staff composition, and fiscal condition. A brief…

College of the Canyons, Santa Clarita, CA.

195

Side effects of clozapine  

Microsoft Academic Search

In addition to the low risk of agranulocytosis, several more frequent side effects are associated with clozapine therapy. We tried to estimate the incidence of these side effects. We analysed 391 treatments in 315 inptients, who received clozapine alone or combined with other neuroleptic and antidepressant drugs. Two thirds were combined treatments, one third were treatments with clozapine alone (i.e.,

Hans Jörg Gaertner; Eberhard Fischer; Joachim Hoss

1989-01-01

196

Earthquake Effects and Experiences  

NSDL National Science Digital Library

This portion of the United States Geological Survey's (USGS) frequently-asked-questions feature on earthquakes addresses what individuals might actually experience during an earthquake. Topics include earthquake motion (rolling or shaking), earthquake effects (ground shaking, surface faulting, ground failure, etc.), earthquake magnitude, what an earthquake feels like, and others. There are also links to additional resources on earthquake effects and experiences.

197

Earthquake Effects and Experiences  

NSDL National Science Digital Library

This portion of the United States Geological Survey's (USGS) frequently-asked-questions feature on earthquakes addresses what individuals might actually experience during an earthquake. Topics include earthquake motion (rolling or shaking), earthquake effects (ground shaking, surface faulting, ground failure, etc.), earthquake magnitude, what an earthquake feels like, and others. There are also links to additional resources on earthquake effects and experiences.

2010-11-23

198

Effects of nuclear weapons  

Microsoft Academic Search

The most recent data concerning the effects associated with explosions of nuclear weapons are presented. The data have been obtained from observations made of effects of nuclear bombing in Japan and tests carried out at the Eniwetok Proving Grounds and Nevada Test Site, as well as from experiments with conventional explosives, and mathematical calculations. The volume is intended for use

Glasstone

1957-01-01

199

Quantum Spin Hall Effect  

Microsoft Academic Search

The quantum Hall liquid is a novel state of matter with profound emergent properties such as fractional charge and statistics. Existence of the quantum Hall effect requires breaking of the time reversal symmetry caused by an external magnetic field. In this work, we predict a quantized spin Hall effect in the absence of any magnetic field, where the intrinsic spin

B. Andrei Bernevig; Shou-Cheng Zhang

2010-01-01

200

Quantum Spin Hall Effect  

Microsoft Academic Search

The quantum Hall liquid is a novel state of matter with profound emergent properties such as fractional charge and statistics. The existence of the quantum Hall effect requires breaking of the time reversal symmetry caused by an external magnetic field. In this work, we predict a quantized spin Hall effect in the absence of any magnetic field, where the intrinsic

B. Andrei Bernevig; Shou-Cheng Zhang

2006-01-01

201

School Quality and Effectiveness  

Microsoft Academic Search

One of the most robust and consistent findings in educational research is that a child's educational attainment is greatly affected by its family background. A crucial issue for policy is whether schools have any effect on children's attainment or whether it is all determined by family background and personality traits. If schools are differentially effective then the school attended matters

Arnaud Chevalier; Peter Dolton; Ros Levacic

2004-01-01

202

Effects on Plants.  

National Technical Information Service (NTIS)

Results of experiments with plants on the effects of low-dose and low-dose rates of low LET radiation are reported. Experiments were conducted on the effects of x and gamma radiation on the production of yellow-green sectors in maize leaves, growth inhibi...

H. H. Smith

1977-01-01

203

Effectiveness of active antennas  

Microsoft Academic Search

Active antennas are miniaturized radio-receiver antennas which use broadband transistor amplifiers to effect added voltage. The effectiveness of such an antenna is the signal to noise ratio at the input of the amplifier. This paper presents an analysis of the noise properties of the most widespread active antenna - a short asymmetrical vibrator with a high-impedance broadband amplifier. It is

B. V. Sosunov

1976-01-01

204

Effective Family Problem Solving.  

ERIC Educational Resources Information Center

Effective family problem solving was studied in 97 families of elementary-school-aged children with definite- and indefinite-solution tasks. Incentive and task independence were manipulated. It was found that definitions of effective problem solving based on directly observed measures of group interaction were more valid than definitions based on…

Blechman, Elaine A.; McEnroe, Michael J.

1985-01-01

205

[Antioxidant effects of melatonin].  

PubMed

Increase in knowledge about reactive oxygen species action mechanisms and oxidative stress effects in living organisms led to intensive seeking for new, more effective substances, which prevent extreme development of oxidative stress or are able to decrease its negative influence, damaging cell structures and many cell functions. These substances are called antioxidants, scavengers, trappers or quenchers. In nineties, melatonin became the centre of the interest in the filed of investigation of antioxidative properties of different chemical substances. This is in living organisms ubiquitous substance with relatively simple chemical structure, good physical properties and wide physiological effects. The main role of endogenous melatonin comprises receptor-mediated biological rhythms synchronisation. Among other functions mentioned later belong anti-gonadotropic, immunotropic and non-receptor-mediated antioxidative effects. Melatonin is said to have also antineoplastic properties. Its anti-aging effect is discutable. PMID:11417192

Konecná, I; Holecek, V; Racek, J; Trefil, L; Rokyta, R

2001-05-01

206

The greenhouse effect  

NASA Astrophysics Data System (ADS)

The greenhouse effect on the Earth is identified by the difference between the effective radiating temperature of the planet and its surface temperature. The difference between the energy emitted by the surface and that emitted upward to space by the upper atmosphere quantifies it; it can therefore be defined as the long wave energy trapped in the atmosphere. Climate forcing and the response of the climate system within which climate feedback mechanisms are contained, will be defined in this review. Quantitative examples will illustrate what could happen if the greenhouse effect is perturbed by the human activities, in particular if atmospheric CO2 concentrations would double in the future. Recent measurements by satellites of the greenhouse effect will be given. The net cooling effect of clouds on the Earth and whether or not there will be less cooling by clouds as the planet warms, are discussed following a series of papers recently published by Ramanathan and his collaborators.

Berger, A.; Tricot, Ch.

1992-11-01

207

[Cholinergic effects of nootropics].  

PubMed

With respect to the enhancing effect of nootropics on learning and memory, the influence of some of these drugs on the high affinity choline uptake has been investigated. Meclofenoxate competes with choline uptake in vitro because of its similar side chain; other nootropics are without in vitro effects. A single dose of pramiracetam enhances the choline uptake in cortex and hippocampus. Application of meclofenoxate decreases the uptake of choline. Other nootropics lack acute effects. Possible increases of uptake after repeated dosage disappear within 24 h. PMID:3149192

Funk, K F; Schmidt, J

1988-01-01

208

From effective interactions to effective operators  

NASA Astrophysics Data System (ADS)

One of the most successful approaches to the nuclear structure of light nuclei is the no-core shell model (NCSM), which describes with very good precision the observed nuclear spectra. In its framework, by means of the Lee Suzuki procedure one derives effective interactions in finite model spaces starting from realistic nucleon-nucleon (NN) potentials; the low-lying energy spectrum is then obtain through the diagonalization of the ab initio effective interactions in large, translationally invariant, many-body basis. In addition to energy levels, one has to obtain good description of the nuclear wave functions; the latter can be tested by computing observables and transition strengths. With a few exceptions, transition strengths and expectation values of observables have been obtained using bare operators restricted to the model space. We have started recently to apply the Lee-Suzuki procedure to general operators and performed tests in restricted model spaces. In this work, we compute expectation values of selected scalar observables and electromagnetic transition strengths using realistic wave functions for nuclei in the p shell. I.S. and B.R.B acknowledge partial support by NFS grants PHY0070858 and PHY0244389. The work was performed in part under the auspices of the U. S. Department of Energy by the University of California, Lawrence Livermore National Laboratory under contract No. W-7405-Eng-48. P.N. received support from LDRD contract 04-ERD-058.

Stetcu, Ionel; Barrett, Bruce R.; Navratil, Petr

2004-10-01

209

Effective Communication: Instructor Guide.  

National Technical Information Service (NTIS)

Effective Communications is part of the Professional Development Series (PDS) of courses developed under the supervision of the Emergency Management Institute (EMI) with the assistance of State and local subject-matter experts. The series includes seven 1...

2002-01-01

210

Physiological Effects of Training.  

National Technical Information Service (NTIS)

With the evolution of exercise science a vast amount of information concerning the physiological effects of training has been generated. Understanding the basic training responses and adaptations of various modes of conditioning can give the clinician ins...

W. J. Kraemer W. L. Daniels

1985-01-01

211

Flexoelectric Effect in Solids  

NASA Astrophysics Data System (ADS)

Flexoelectricity-the coupling between polarization and strain gradients-is a universal effect allowed by symmetry in all materials. Following its discovery several decades ago, studies of flexoelectricity in solids have been scarce due to the seemingly small magnitude of this effect in bulk samples. The development of nanoscale technologies, however, has renewed the interest in flexoelectricity, as the large strain gradients often present at the nanoscale can lead to strong flexoelectric effects. Here we review the fundamentals of the flexoelectric effect in solids, discuss its presence in many nanoscale systems, and look at potential applications of this electromechanical phenomenon. The review also emphasizes the many open questions and unresolved issues in this developing field.

Zubko, Pavlo; Catalan, Gustau; Tagantsev, Alexander K.

2013-07-01

212

Vaccine herd effect.  

PubMed

Vaccination ideally protects susceptible populations at high risk for complications of the infection. However, vaccines for these subgroups do not always provide sufficient effectiveness. The herd effect or herd immunity is an attractive way to extend vaccine benefits beyond the directly targeted population. It refers to the indirect protection of unvaccinated persons, whereby an increase in the prevalence of immunity by the vaccine prevents circulation of infectious agents in susceptible populations. The herd effect has had a major impact in the eradication of smallpox, has reduced transmission of pertussis, and protects against influenza and pneumococcal disease. A high uptake of vaccines is generally needed for success. In this paper we aim to provide an update review on the herd effect, focusing on the clinical benefit, by reviewing data for specific vaccines. PMID:21604922

Kim, Tae Hyong; Johnstone, Jennie; Loeb, Mark

2011-05-23

213

Vaccine herd effect  

PubMed Central

Vaccination ideally protects susceptible populations at high risk for complications of the infection. However, vaccines for these subgroups do not always provide sufficient effectiveness. The herd effect or herd immunity is an attractive way to extend vaccine benefits beyond the directly targeted population. It refers to the indirect protection of unvaccinated persons, whereby an increase in the prevalence of immunity by the vaccine prevents circulation of infectious agents in susceptible populations. The herd effect has had a major impact in the eradication of smallpox, has reduced transmission of pertussis, and protects against influenza and pneumococcal disease. A high uptake of vaccines is generally needed for success. In this paper we aim to provide an update review on the herd effect, focusing on the clinical benefit, by reviewing data for specific vaccines.

Kim, Tae Hyong; Johnstone, Jennie; Loeb, Mark

2011-01-01

214

Coping with Side Effects  

MedlinePLUS

... Depression When should I call my doctor? Side Effect Strategies for Coping Fatigue Lingering feeling of tiredness Most common symptom Some medications Plenty of rest, with short naps Light to moderate physical activity Ask others to help ...

215

Demonstrating Product Effectiveness  

Center for Drug Evaluation (CDER)

Text Version... know how to do this with appropriate correction, ... effect. If the trial did not have assay sensitivity, then ... That is, the trial itself does not show the study's ... More results from www.fda.gov/downloads/drugs/guidancecomplianceregulatoryinformation

216

Munroe Effect Breaching Device.  

National Technical Information Service (NTIS)

There is provided in the present invention an unlined, Munroe Effect device for breaching structures in urban terrain during combat or emergency operations. The device is constructed as an unlined, linear, shaped explosive charge which upon detonation dir...

J. S. Foster J. A. Zehmer

1982-01-01

217

Effectiveness of Navy Advertising.  

National Technical Information Service (NTIS)

This analysis was performed to evaluate the effectiveness of Navy recruiting advertising in producing fully qualified, first-term enlistments during calendar years 1976 and 1977. Advertising expenditures and enlistment data were allocated to the county le...

T. C. Williams

1978-01-01

218

Coherent Backscattering Opposition Effect.  

National Technical Information Service (NTIS)

We have measured the opposition effect, the nonlinear surge in reflectance seen in particulate materials as phase angle approaches zero degrees, in a suite of materials of varying particle size and reflectance. These samples were illuminated by linearly a...

R. M. Nelson B. W. Hapke W. D. Smythe V. Gharakanian P. Herrera

1993-01-01

219

[Genetic effects of radiation].  

PubMed

This paper is a short review of genetic effect of radiation. This includes methods and results of a large-scale genetic study on specific loci in mice and of various studies in the offspring of atomic-bomb survivors. As for the latter, there is no results obtained which suggest the effect of parental exposure to radiation. Further, in recent years, studies are conducted to the offspring born to parents who were survivors of childhood cancers. In several reports, the mean gonad dose is quite large whereas in most instances, the results do not indicate genetic effect following parental exposure to radiation. Possible reasons for the difficulties in detecting genetic effect of radiation are discussed. PMID:22514926

Nakamura, Nori

2012-03-01

220

Radiation effects in space  

SciTech Connect

The paper discusses the radiation environment in space that astronauts are likely to be exposed to. Emphasis is on proton and HZE particle effects. Recommendations for radiation protection guidelines are presented. (ACR)

Fry, R.J.M.

1986-01-01

221

Substituent Effect in Ketoferrocenes.  

National Technical Information Service (NTIS)

The effect of carbonyl-group on the redox potential and Moessbauer parameters was studied in ketoferrocenes and chalcone analogous ferrocene derivatives. Interaction of electron-donating and electron-withdrawing substituents and the carbonyl-group is disc...

A. G. Nagy

1983-01-01

222

Hall Effect Spintronics.  

National Technical Information Service (NTIS)

Following the original project continued research devoted to manufacture, study and optimization of materials suitable for spintronics applications based on the extraordinary Hall effect (EHE). The work was focused on three major tasks: 1. Preparation and...

A. Gerber

2011-01-01

223

Cost Effectiveness Analysis.  

National Technical Information Service (NTIS)

This section presents the general cost-effectiveness analysis procedures appropriate to small communal and onsite waste-water treatment systems design. The cost components of the analysis will first be defined and the general procedures for their determin...

1995-01-01

224

Chemical Structural Aging Effects.  

National Technical Information Service (NTIS)

This program is determining the individual chemical rate processes that govern the aging of ANB-3066 propellant, and it is attempting to establish the effect of chemical (compositional) changes upon the system's mechanical response to enable better utiliz...

G. E. Myers A. B. Tipton

1972-01-01

225

Coefficients of Effective Length.  

ERIC Educational Resources Information Center

Under certain conditions, a validity Coefficient of Effective Length (CEL) can produce highly misleading results. A modified coefficent is suggested for use when empirical studies indicate that underlying assumptions have been violated. (Author/BW)

Edwards, Roger H.

1981-01-01

226

Nocturnal aircraft noise effects.  

PubMed

Noise protection associated with the construction and extension of airports in the Federal Republic of Germany has been regulated by the law for protection against aircraft noise since 1971. This legislation is due for revision because of different aspects. One aspect is the growth of air traffic which has led many airports to the limits of their capacity and in search of new ways of adaptation to the increasing demand for flight services. Another aspect is the increasing concern of the population about noise effects which has to be addressed by better protection against the effects of aircraft noise. The framework conditions of policy in terms of society as a whole, its health and economic environment need to be put into effect by political action. Science can contribute to this goal by performing noise effects research and by providing recommendations to the political body. However, it remains controversial, what measures are necessary or adequate to assure effective protection of the population against aircraft noise. This is particularly true for the protection of rest and sleep at night. The problem of finding a common basis for adequate recommendations is associated with (1) the low number of primary studies, which also exhibited highly variable results and assessments, (2) the handling of acoustic or psycho-acoustic dimensions for quantifying psychological or physiological reactions, and (3) the conception of how far preventive measures have to go to prove effective. With this in mind, the DLR Institute for Aerospace Medicine is conducting a large-scale, multi-stage study for investigating the acute effects of nocturnal aircraft noise on human sleep. This enterprise is implemented in the framework of the HGF/DLR project "Quiet Air Traffic" for developing sustainable assessment criteria for human-specific effects of aircraft noise at night. PMID:15070533

Basner, M; Samel, A

227

Pupillary Stroop effects  

Microsoft Academic Search

We recorded the pupil diameters of participants performing the words’ color-naming Stroop task (i.e., naming the color of\\u000a a word that names a color). Non-color words were used as baseline to firmly establish the effects of semantic relatedness\\u000a induced by color word distractors. We replicated the classic Stroop effects of color congruency and color incongruency with\\u000a pupillary diameter recordings: relative

Bruno Laeng; Marte Ørbo; Terje Holmlund; Michele Miozzo

2011-01-01

228

Security effectiveness review (SER)  

Microsoft Academic Search

As part of the on-going DOE\\/Russian MPC and A activities at the Institute of Physics and Power Engineering (IPPE) and in order to provide a basis for planning MPC and A enhancements, an expedient method to review the effectiveness of the MPC and A system has been adopted. These reviews involve the identification of appropriate and cost-effective enhancements of facilities

I. Kouprianova; D. Ek; R. Showalter; M. Bergman

1998-01-01

229

The Doppler Effect  

NSDL National Science Digital Library

This Flash animation provides a simulation of the Doppler effect. The user can change the speed of the wave source and can move a microphone to detect the wave frequency at different points relative to the moving source. The resulting wave pattern can be both observed and heard. Instructional notes outlining the details of the Doppler effect are provided. This material is part of a web site for a second semester physics course for majors covering gravity, fluids, waves, and thermodynamics.

Fowler, Michael; Welch, Heather

2008-07-31

230

Cytogenetic effects of cyclamates  

Microsoft Academic Search

PHA-stimulated human peripheral lymphocytes were used as a model system for assessing the in vitro effects of calcium cyclamate. Techniques of autoradiography, cytological staining, cell counting, liquid scintillation and karyotyping were used to study the cytogenetic damage and biochemical effects of calcium cyclamate when assayed in 24 hour intervals for 96 hours. The cells were exposed to 10(-2) and 10(-3)

E. W. Jemison; K. Brown; B. Rivers; R. Knight

1984-01-01

231

Health effects of ozone  

SciTech Connect

The author comments on Morton Lippmann's paper entitled Health Effects of Ozone which was presented at the 82nd Air and Waste Management Association Annual Meeting and Exhibition, held in Anaheim, California in June 1989. Thanks to the efforts of Dr. Lippmann we have a better understanding of the acute, prolonged and chronic exposure health effects of ozone and are in a better position to receive public support to clean the air.

McKee, D. (Environmental Protection Agency, Research Triangle Park, NC (USA))

1989-09-01

232

Doppler Effect Applet  

NSDL National Science Digital Library

This applet lets students interactively experience the Doppler effect. The user can adjust the position of an "observer" relative to the wave source (a jet plane), change the plane's speed, observe how the waveforms change in frequency and wavelength as the plane passes by the observer, and listen to the change in pitch of the sound. There are also links to additional information on the Doppler effect, the physics of sound, and other sound-based applets.

233

Acid Rain Effects  

NSDL National Science Digital Library

Learners conduct a simple experiment to model and explore the harmful effects of acid rain (vinegar) on living (green leaf and eggshell) and non-living (paper clip) objects. Learners observe the effects over a period of days. This activity has links to other activities which can be combined to make a larger lesson. Resource contains vocabulary definitions and suggestions for assessment, extensions, and scaling for different levels of learners.

Kolenbrander, Amy; Yowell, Janet; Mach, Natalie; Zarske, Malinda S.; Carlson, Denise

2004-01-01

234

The Disappearing Delaware Effect  

Microsoft Academic Search

Refining and extending the methodology introduced by Daines (2001), I present evidence that small Delaware firms were worth more than small non-Delaware firms during the period 1991--1996 but not afterwards. I also present evidence that larger firms, which comprise 98% of my sample by size, exhibit no Delaware effect for any year during the period 1991--2002. Thus the Delaware effect

Guhan Subramanian

2004-01-01

235

Spin Hall Effect Transistor  

Microsoft Academic Search

The field of semiconductor spintronics explores spin-related quantum relativistic phenomena in solid-state systems. Spin transistors and spin Hall effects have been two separate leading directions of research in this field. We have combined the two directions by realizing an all-semiconductor spin Hall effect transistor. The device uses diffusive transport and operates without electrical current in the active part of the

Jörg Wunderlich; Byong-Guk Park; Andrew C. Irvine; Liviu P. Zârbo; Eva Rozkotová; Petr Nemec; Vít Novák; Jairo Sinova; Tomás Jungwirth

2010-01-01

236

The extraterrestrial Casimir Effect  

NASA Astrophysics Data System (ADS)

Application of the Electro-Gravi-Magnetic (EGM) Photon radiation method to the Casimir Effect (CE), suggests that the experimentally verified (terrestrially) neutrally charged Parallel-Plate configuration force, may differ within extraterrestrial gravitational environments from the gravitationally independent formulation by Casimir. Consequently, the derivation presented herein implies that a gravitationally dependent CE may become an important design factor in nanotechnology for extraterrestrial applications (ignoring finite conductivity + temperature effects and evading the requirement for Casimir Force corrections due to surface roughness).

Storti, Riccardo C.

2011-09-01

237

The Uniform Rugosity Effect  

Microsoft Academic Search

Relying on the effect of microscopic asperities, one can mathematically justify that viscous fluids adhere completely on the\\u000a boundary of an impermeable domain. The rugosity effect accounts asymptotically for the transformation of complete slip boundary\\u000a conditions on a rough surface in total adherence boundary conditions, as the amplitude of the rugosities vanishes. The decreasing\\u000a rate (average velocity divided by the

Matthieu Bonnivard; Dorin Bucur

2011-01-01

238

Pleiotropic effects of pitavastatin.  

PubMed

3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors (statins) are established first line treatments for hypercholesterolaemia. In addition to the direct effects of statins in reducing concentrations of atherogenic low density lipoprotein cholesterol (LDL-C), several studies have indicated that the beneficial effects of statins may be due to some of their cholesterol-independent, multiple (pleiotropic) effects which may differ between different members of the class. Pitavastatin is a novel synthetic lipophilic statin that has a number of pharmacodynamic and pharmacokinetic properties distinct from those of other statins, which may underlie its potential pleiotropic benefits in reducing cardiovascular risk factors. This review examines the principal pleiotropic effects of pitavastatin on endothelial function, vascular inflammation, oxidative stress and thrombosis. The article is based on a systematic literature search carried out in December 2010, together with more recent relevant publications where appropriate. The available data from clinical trials and in vitro and animal studies suggest that pitavastatin is not only effective in reducing LDL-C and triglycerides, but also has a range of other effects. These include increasing high density lipoprotein cholesterol, decreasing markers of platelet activation, improving cardiac, renal and endothelial function, and reducing endothelial stress, lipoprotein oxidation and, ultimately, improving the signs and symptoms of atherosclerosis. It is concluded that the diverse pleiotropic actions of pitavastatin may contribute to reducing cardiovascular morbidity and mortality beyond that achieved through LDL-C reduction. PMID:22053916

Davignon, Jean

2012-04-01

239

Effective Transport Properties  

NASA Astrophysics Data System (ADS)

In this chapter we study a particular case of multiphase systems, namely two-phase materials in which one of the phases is randomly dispersed in the other, so that the composite can be viewed on a macroscale as an effective continuum, with well defined properties. In general, the theoretical determination of the parameter for an effective medium requires, as a rule, the solution of a corresponding transport problem at the microscale, which takes into account the morphology of the system and its evolution. As the mathematical problem is well-posed on a microscale, this can be accomplished using, for example, the multiple scale approach shown in Chap. 11 ; however, the task requires massive computations and is therefore difficult to implement from the practical standpoint. Here, instead, we focus on a deterministic approach to the problem, where the geometry and spatial configuration of the particles comprising the included phase are given and the solution to the microscale problem is therefore sought analytically. As examples, we study the effective thermal conductivity of solid reinforced materials (Sect. 10.1), the effective viscosity of non-colloidal suspensions (Sect. 10.2), the effective permeability of porous materials (10.3) and the effective self- and gradient diffusivities of colloidal suspensions (Sect. 10.4). Then, in Sect. 10.5, an alternative dynamic definition of the transport coefficients is considered, which can also serve as a basis to determine the effective properties of complex systems.

Mauri, Roberto

240

Magnetoelectric effects in manganites  

NASA Astrophysics Data System (ADS)

Research on manganites has been conducted for more than half century. Recent discoveries of colossal responses to external fields such as colossal magnetoresistance effects and correlation among spin, orbital, and lattice in phase separated manganites and multiferroic manganites have motivated me to understand these materials. The main purpose of this dissertation is to understand magnetoelectric effects in phase separated (La1-yPr y)1-xCaxMnO3 (LPCMO) thin films and multiferroic BiMnO3 (BMO) thin films. First, high quality phase separated manganite thin films have been successfully grown. To grow the high quality manganite thin films, extensive effort was devoted to fine tuning of oxygen pressure, temperature, and laser fluence during film growth. As-grown films were characterized with various ex-situ techniques: magnetization measurements, transport measurements, x-ray diffraction, atomic force microscopy, and/or transmission electron microscopy to remove the effects of impurities and unwanted strains except substrate induced strain. Second, three major results were obtained in high quality phase separated LPCMO thin films. These results are based on the dynamic nature of phases in LPCMO. 1) LPCMO thin films showed single domain to multi-domain transition during cooling. This transition can be tuned by substrate stress induced in-plane magnetic anisotropy. 2) Evidence for the origin of colossal electroresistance (CER) effect has been observed. The CER is triggered by dielectrophoresis, or movements of ferromagnetic metallic (FMM) phase, which is manifested in anisotropic transport properties in microfabricated LPCMO cross structures. This fluidic nature of the FMM phase in LPCMO under high electric fields lead to exotic magnetoelectric effects. 3) Electric field effects on magnetotransport properties have been observed. This phenomena can also be tuned by the combined effect of substrate strain and current flow. This combined effect of electric and magnetic fields and strain at the interface of LPCMO suggest new ways to control magnetism (magnetotransport) with electric fields. Third, impurity-free and epitaxial BMO thin films were grown. These films showed ferromagnetism and ferroelectricity at low temperature. Magnetoelectric effects are discussed, especially magnetization change due to electric fields.

Jeen, Hyoung Jeen

241

Nonperturbative effects in supergravity  

NASA Astrophysics Data System (ADS)

A promising candidate for a fundamental theory of nature, incorporating both general relativity and quantum mechanics, is string theory. This theory is based on one-dimensional extended objects that move through spacetime. However, string theory is most naturally formulated in ten dimensions. To consider string theory in four dimensions one can compactify six dimensions (by making them very small) and compute the effect on the theory. This yields a certain four-dimensional theory. Furthermore, string theory contains also extended objects of higher dimensions, these are called D-branes (think for example of a membrane). Their effect on the four-dimensional theory should be considered as well. This is what we have done, in a certain setting, and the results are presented in this thesis. We work in the supergravity approximation, which means that we restrict ourselves to length scales (much) smaller than the string length. In this approximation the D-branes are described by solitonic solutions to the supergravity equations of motion. We consider the N=2 supergravity theory in four dimensions resulting from compactifying type IIA supergravity (the low energy limit of type IIA string theory) on a six-dimensional Calabi-Yau manifold. Furthermore we consider the membrane and NS five-brane. In the four-dimensional theory they can be described by finite action solutions to the equations of motion. We then construct the effective action which incorporates the effects of the membrane and the five-brane, respectively. The effective N=2 supergravity action (the supergravity multiplet coupled to a hypermultiplet) in four dimensions incorporating the one-loop effects in the background of a NS five-brane is computed by a 'traditional' instanton calculation. The effective action incorporating the one-loop effect in the presence of a membrane is computed using knowledge of the symmetries of the action and their breaking by the membrane. These nonperturbative corrections affect the hypermultiplet sector of the N=2 supergravity theory. Furthermore, we gauge an isometry of the hypermultiplet sector. This produces a potential. This potential has certain minima and the effect of the nonperturbative membrane corrections is to produce a metastable minimum which can have a positive value: a de Sitter minimum.

Davidse, Marijn

2006-01-01

242

A "voice inversion effect?".  

PubMed

Voice is the carrier of speech but is also an "auditory face" rich in information on the speaker's identity and affective state. Three experiments explored the possibility of a "voice inversion effect," by analogy to the classical "face inversion effect," which could support the hypothesis of a voice-specific module. Experiment 1 consisted of a gender identification task on two syllables pronounced by 90 speakers (boys, girls, men, and women). Experiment 2 consisted of a speaker discrimination task on pairs of syllables (8 men and 8 women). Experiment 3 consisted of an instrument discrimination task on pairs of melodies (8 string and 8 wind instruments). In all three experiments, stimuli were presented in 4 conditions: (1) no inversion; (2) temporal inversion (e.g., backwards speech); (3) frequency inversion centered around 4000 Hz; and (4) around 2500 Hz. Results indicated a significant decrease in performance caused by sound inversion, with a much stronger effect for frequency than for temporal inversion. Interestingly, although frequency inversion markedly affected timbre for both voices and instruments, subjects' performance was still above chance. However, performance at instrument discrimination was much higher than for voices, preventing comparison of inversion effects for voices vs. non-vocal stimuli. Additional experiments will be necessary to conclude on the existence of a possible "voice inversion effect." PMID:15177788

Bédard, Catherine; Belin, Pascal

2004-07-01

243

System Effectiveness Model Formulation  

SciTech Connect

Evaluation of system effectiveness has numerous pitfalls. System objectives may be poorly defined, may shift during the system life or may be hard to quantify. Further, individual perceptions of the quantifications may differ. Whatever the cause, system effectiveness has been an elusive term to quantitatively define. The proposed model presents a quantitative system effectiveness model and establishes a utilitarian approach for its use with the illustrative application to a nuclear safeguards system. The model uses the Type I and Type II statistical error rates as input to the component or subsystem effectiveness calculation which, when combined using a utilitarian methodology, quantify the overall system effectiveness. The methodology will use a survey of expert judgment to determine the relative importance of the individual subsystems through a statistically designed web survey. The web based survey will be available to nuclear material protection, control, and accounting experts attending the 2008 INMM conference. This model and methodology will provide a repeatable quantifiable measure for any system but in this case a simple safeguards system is used as an example.

Coates, Cameron W [ORNL; Jackson, Denise F [ORNL

2008-01-01

244

Mitochondrial threshold effects.  

PubMed Central

The study of mitochondrial diseases has revealed dramatic variability in the phenotypic presentation of mitochondrial genetic defects. To attempt to understand this variability, different authors have studied energy metabolism in transmitochondrial cell lines carrying different proportions of various pathogenic mutations in their mitochondrial DNA. The same kinds of experiments have been performed on isolated mitochondria and on tissue biopsies taken from patients with mitochondrial diseases. The results have shown that, in most cases, phenotypic manifestation of the genetic defect occurs only when a threshold level is exceeded, and this phenomenon has been named the 'phenotypic threshold effect'. Subsequently, several authors showed that it was possible to inhibit considerably the activity of a respiratory chain complex, up to a critical value, without affecting the rate of mitochondrial respiration or ATP synthesis. This phenomenon was called the 'biochemical threshold effect'. More recently, quantitative analysis of the effects of various mutations in mitochondrial DNA on the rate of mitochondrial protein synthesis has revealed the existence of a 'translational threshold effect'. In this review these different mitochondrial threshold effects are discussed, along with their molecular bases and the roles that they play in the presentation of mitochondrial diseases.

Rossignol, Rodrigue; Faustin, Benjamin; Rocher, Christophe; Malgat, Monique; Mazat, Jean-Pierre; Letellier, Thierry

2003-01-01

245

Effective Nutritional Supplement Combinations  

NASA Astrophysics Data System (ADS)

Few supplement combinations that are marketed to athletes are supported by scientific evidence of their effectiveness. Quite often, under the rigor of scientific investigation, the patented combination fails to provide any greater benefit than a group given the active (generic) ingredient. The focus of this chapter is supplement combinations and dosing strategies that are effective at promoting an acute physiological response that may improve/enhance exercise performance or influence chronic adaptations desired from training. In recent years, there has been a particular focus on two nutritional ergogenic aids—creatine monohydrate and protein/amino acids—in combination with specific nutrients in an effort to augment or add to their already established independent ergogenic effects. These combinations and others are discussed in this chapter.

Cooke, Matt; Cribb, Paul J.

246

Photoelectric Effect Model  

NSDL National Science Digital Library

The EJS Photoelectric Effect model simulates the Photoelectric effect discovered by Hertz in 1887 and described theoretically by Einstein in 1905. Light of a given frequency (and energy) shines on a metal. If the frequency (energy) of the light is greater than the work function, W, of the metal, electrons are ejected and can form a current (which is shown in milliAmperes). These photoelectrons will also have a kinetic energy if the energy of the light is greater than the workfunction. they will have kinetic energy. If subjected to an electric potential the electrons can be stopped from reaching the plate and stop current from flowing in a circuit. The EJS Photoelectric Effect model was created using the Easy Java Simulations (EJS) modeling tool. It is distributed as a ready-to-run (compiled) Java archive. Double clicking the ejs_qm_photoelectric.jar file will run the program if Java is installed.

Palop, Jose I.

2010-07-16

247

??-Corrected Chiral Magnetic Effect  

NASA Astrophysics Data System (ADS)

Using the AdS/CFT correspondence, the effect of ??-correction on the value of Chiral Magnetic Effect (CME) is computed by adding a number of spinning probe D7-branes in the ??-corrected background. We numerically show that the magnitude of CME rises in the presence of ??-correction for massive solutions and this increase is more sensible at higher temperatures. However, this value does not change for massless solution. Although some of the D7-brane embeddings have no CME, after applying the ??-correction they find a non-zero value for the CME. We also show that the effect of ??-correction removes the singularity from some of the D7-brane embeddings.

Ali-Akbari, M.; Taghavi, S. F.

2013-07-01

248

Health effects of ozone  

SciTech Connect

The 1989 Critical Review on Health Effects of Ozone by Morton Lippmann is a valuable contribution to the literature on criteria air pollutants. In a comprehensive fashion, the paper methodically examines key areas relevant to understanding effects of ozone on human health: exposure and dosimetry, populations and responses of concern, research approaches, and effects upon specific pulmonary endpoints from single and multiple exposures. Dr. Lippmann has provided us with more than an excellent summary; whenever possible, he has thoughtfully integrated findings from the relevant disciplines of animal toxicology, epidemiology, field studies and controlled clinical studies, and has emphasized exposure-response relationship in arriving at his conclusions. Going beyond the call of duty, he has concluded with a Critical Preview recommending a shape and form for the ozone standard of the future.

Utell, M.J. (Univ. of Rochester School of Medicine, NY (USA))

1989-09-01

249

Spin Hall Effect Transistor  

NASA Astrophysics Data System (ADS)

The field of semiconductor spintronics explores spin-related quantum relativistic phenomena in solid-state systems. Spin transistors and spin Hall effects have been two separate leading directions of research in this field. We have combined the two directions by realizing an all-semiconductor spin Hall effect transistor. The device uses diffusive transport and operates without electrical current in the active part of the transistor. We demonstrate a spin AND logic function in a semiconductor channel with two gates. Our study shows the utility of the spin Hall effect in a microelectronic device geometry, realizes the spin transistor with electrical detection directly along the gated semiconductor channel, and provides an experimental tool for exploring spin Hall and spin precession phenomena in an electrically tunable semiconductor layer.

Wunderlich, Jörg; Park, Byong-Guk; Irvine, Andrew C.; Zârbo, Liviu P.; Rozkotová, Eva; Nemec, Petr; Novák, Vít; Sinova, Jairo; Jungwirth, Tomás

2010-12-01

250

Aviation noise effects  

NASA Astrophysics Data System (ADS)

This report summarizes the effects of aviation noise in many areas, ranging from human annoyance to impact on real estate values. It also synthesizes the findings of literature on several topics. Included in the literature were many original studies carried out under FAA and other Federal funding over the past two decades. Efforts have been made to present the critical findings and conclusions of pertinent research, providing, when possible, a bottom line conclusion, criterion or perspective. Issues related to aviation noise are highlighted, and current policy is presented. Specific topic addressed include: annoyance; Hearing and hearing loss; noise metrics; human response to noise; speech interference; sleep interference; non-auditory health effects of noise; effects of noise on wild and domesticated animals; low frequency acoustical energy; impulsive noise; time of day weightings; noise contours; land use compatibility; and real estate values. This document is designed for a variety of users, from the individual completely unfamiliar with aviation noise to experts in the field.

Newman, J. S.; Beattie, K. R.

1985-03-01

251

Spin Hall effect transistor.  

PubMed

The field of semiconductor spintronics explores spin-related quantum relativistic phenomena in solid-state systems. Spin transistors and spin Hall effects have been two separate leading directions of research in this field. We have combined the two directions by realizing an all-semiconductor spin Hall effect transistor. The device uses diffusive transport and operates without electrical current in the active part of the transistor. We demonstrate a spin AND logic function in a semiconductor channel with two gates. Our study shows the utility of the spin Hall effect in a microelectronic device geometry, realizes the spin transistor with electrical detection directly along the gated semiconductor channel, and provides an experimental tool for exploring spin Hall and spin precession phenomena in an electrically tunable semiconductor layer. PMID:21205664

Wunderlich, Jörg; Park, Byong-Guk; Irvine, Andrew C; Zârbo, Liviu P; Rozkotová, Eva; Nemec, Petr; Novák, Vít; Sinova, Jairo; Jungwirth, Tomás

2010-12-24

252

The uncontrollable placebo effect  

Microsoft Academic Search

Objective:\\u000a \\u000a \\u000a To analyse the role of the control group in the methodology of clinical placebo effect evaluating trials.\\u000a \\u000a \\u000a Setting:\\u000a \\u000a \\u000a Department of Medical Philosophy and Clinical Theory, University of Copenhagen.\\u000a \\u000a \\u000a Methods:\\u000a \\u000a \\u000a A theoretical methodological analysis.\\u000a \\u000a \\u000a Results:\\u000a \\u000a \\u000a At least with present trial designs, it is impossible, with certainty, to exclude a potential placebo effect from the so-called\\u000a control group. The placebo effect,

A. Hróbjartsson

1996-01-01

253

Developing Proto-Type Pump Which Would Utilize Unique Thermo-Dynamic Cycle. Final Report.  

National Technical Information Service (NTIS)

The work described was to develop a prototype pump working on the thermosyphon principle and useful as a circulating device for a solar domestic hot water system. Numerous photographs and drawings illustrate the device. (ERA citation 09:000406)

1983-01-01

254

Micro-Fluid Dynamical Analysis of Evaporating Flows in Heat Pipes.  

National Technical Information Service (NTIS)

Heat pipe systems utilizing phase changing heat transfer concepts are introduced, including micro heat pipes, a separate type heat pipe heat exchanger, and heat pipe turbines. Inside these heat pipes, contrary to the conventional thermosyphon, evaporation...

K. Oshima N. Izutsu

1988-01-01

255

Pseudoprogression and treatment effect.  

PubMed

The standard of care for newly diagnosed malignant glioblastoma entails postoperative radiotherapy and adjuvant chemotherapy with temozolomide. There has been an increase in the incidence of enhancing and progressive lesions seen on magnetic resonance imaging (MRI) following treatment. Conventional MRI with gadolinium contrast is unable to distinguish between the effects of treatment and actual tumor recurrence. New modalities have provided additional information for distinguishing treatment effects from tumor progression but are not 100% sensitive or specific in diagnosing progression. Novel radiographic or nonradiographic biomarkers with sensitivity and specificity verified in large randomized clinical trials are needed to detect progression. PMID:22440871

Jahangiri, Arman; Aghi, Manish K

2012-02-14

256

Mesoscopic Josephson effect  

NASA Astrophysics Data System (ADS)

In the classical Josephson effect the phase difference across the junction is well defined, and the supercurrent is reduced only weakly by phase diffusion. For mesoscopic junctions with small capacitance the phase undergoes large quantum fluctuations, and the current is also decreased by Coulomb blockade effects. We discuss the behavior of the current-voltage characteristics in a large range of parameters comprising the phase diffusion regime with coherent Josephson current as well as the supercurrent peak due to incoherent Cooper pair tunneling in the Coulomb blockade regime.

Grabert, Hermann; Ingold, Gert-Ludwig

1999-05-01

257

Predicting drug effectiveness.  

PubMed

Two new diagnostic tests which evaluate a patient's HIV resistance to antiviral drugs were scheduled to be on the market in July. The tests are being marketed under the trademarks Antivirogram, by Laboratory Corporation of America, and VircoGEN by VIRCO. Both companies say that when the tests are used together, they will predict which drugs a patient will respond to, leading to more effective treatment decisions. Studies were conducted to predict the effectiveness of Ritonavir/Saquinavir therapy, and the results were very promising. PMID:11365696

1998-08-01

258

Chiral magnetic effect  

SciTech Connect

Topological charge changing transitions can induce chirality in the quark-gluon plasma by the axial anomaly. We study the equilibrium response of the quark-gluon plasma in such a situation to an external magnetic field. To mimic the effect of the topological charge changing transitions we will introduce a chiral chemical potential. We will show that an electromagnetic current is generated along the magnetic field. This is the chiral magnetic effect. We compute the magnitude of this current as a function of magnetic field, chirality, temperature, and baryon chemical potential.

Fukushima, Kenji [Yukawa Institute, Kyoto University, Kyoto (Japan); Kharzeev, Dmitri E.; Warringa, Harmen J. [Department of Physics, Brookhaven National Laboratory, Upton New York 11973 (United States)

2008-10-01

259

Stormwater BMP Effectiveness Assessment Toolkit  

EPA Science Inventory

US EPA has identified stormwater BMP effectiveness as a priority research need. Effective protection of biotic integrity requires that processes maintaining the diversity of physical habitats be protected. Methods are needed to evaluate the effectiveness of existing Stormwater ...

260

The Effects of Nuclear War.  

National Technical Information Service (NTIS)

The study examines the full range of effects that nuclear war would have on civilians: direct effects from blast and radiation; and indirect effects from economic, social, and political disruption. Particular attention is devoted to the ways in which the ...

1979-01-01

261

Side Effects of Hormone Therapy  

MedlinePLUS

... PCF Spotlight Glossary African American Men Living with Prostate Cancer Side Effects of Hormone Therapy Side Effects Urinary ... to evaluate its use in men with advanced prostate cancer. If the approach proves to be as effective ...

262

Petroleum effects in the Arctic  

SciTech Connect

This book presents papers on the environmental and biological effects of oil spills. Topics considered include the Arctic marine ecosystem, the physical and chemical fate of spilled oil, the effects of hydrocarbons on microorganisms and petroleum biodegradation in arctic ecosystems, the effects of oil on arctic invertebrates, the effects of oil on fish, a risk assessment of oil on arctic marine birds, the effects of petroleum on marine mammals, and the effects of petroleum activities on the ecology of arctic man.

Engelhardt, F.R.

1985-01-01

263

Structural Effects on Daylighting  

Microsoft Academic Search

Optimum daylighting of interior spaces is most effectively achieved by pure archi- tectural (or: structural) measures of which the most basic ones are the dimension- ing and positioning of daylight openings in the building envelope as well as geome- try and surface characteristics of the considered space. Multidimensional regres- sion analyses with such parameters performed for a number of simple

Friedrich Sick

264

Effective classical partition functions  

SciTech Connect

We present a method by which a quantum-mechanical partition function can be approximated from below by an effective classical partition function. The associated potential is obtained by a simple smearing procedure. For a strongly anharmonic oscillator and a double-well potential, the lowest approximation gives a free energy which is accurate to a few percent, even at zero temperature.

Feynman, R.P.; Kleinert, H.

1986-12-01

265

Effective receivables management.  

PubMed

To prevent the accumulation of accounts in the "greater than 120 days" category, receivable management strategies must be revised. The keys to managing receivables in the current healthcare environment have been presented. With the healthcare industry likely to remain credit-oriented, those organizations that effectively manage receivables and minimize their cost of working capital will win a real competitive advantage. PMID:10303035

Raymond, G B

1988-12-01

266

EFFECTS ON SALTWATER ORGANISMS  

EPA Science Inventory

The literature review summarizes current data on the effects of pesticides and metals on marine organisms, aquatic environmental research methods, bioaccumulation of pollutants by estuarine and marine organisms and in water/sediment residues and biota. Results of studies of the e...

267

Cardiovascular Effects of Caffeine  

PubMed Central

A review of the literature on the cardiovascular effects of caffeine indicates that moderate caffeine consumption does not cause cardiac arrhythmias, hypertension, or an increased incidence of coronary heart disease. Caffeine use is often associated with atherogenic behavior, such as cigarette smoking. Failure to take into account covariables for cardiovascular disease could be responsible for commonly held misconceptions about caffeine and heart disease.

Myers, Martin G.

1992-01-01

268

Health effects of ozone  

Microsoft Academic Search

It is an honor to have the opportunity to comment on Dr. Morton Lippmann's excellent review on the health effects of ozone, which was presented at the 82nd Air and Waste Management Association Annual Meeting and Exhibition held in Anaheim, California in June 1989. It is comprehensive in citing all of the pertinent references, interpretative in its review of the

McClellan

1989-01-01

269

Developing Effective Training Programs.  

ERIC Educational Resources Information Center

Focusing on research administrators, discusses how an effective training program improves employee performance by including comprehensive needs assessment, employing appropriate training methodologies, and anticipating factors beyond the actual training event that influence the transfer of skills from the training environment to the work…

Wagonhurst, Carole

2002-01-01

270

Designing Effective Posters  

NSDL National Science Digital Library

This website presents an online tutorial about creating effective poster presentations. The site guides users through the basics of poster design, which should free the presenter to focus on discussion of essential elements of the work. Decisions about poster format and design which contribute to efficient and accurate transfer of information using this medium are also discussed.

Radel, Jeff; Center, Ku M.

271

The nonlinear Fano effect  

Microsoft Academic Search

The Fano effect is ubiquitous in the spectroscopy of, for instance, atoms, bulk solids and semiconductor heterostructures. It arises when quantum interference takes place between two competing optical pathways, one connecting the energy ground state and an excited discrete state, the other connecting the ground state with a continuum of energy states. The nature of the interference changes rapidly as

M. Kroner; A. O. Govorov; S. Remi; B. Biedermann; S. Seidl; A. Badolato; P. M. Petroff; W. Zhang; R. Barbour; B. D. Gerardot; R. J. Warburton; K. Karrai

2008-01-01

272

Effect of a \\  

Microsoft Academic Search

3 studies with 104 undergraduates investigated the effect of a chunked typography on the reading rate and comprehension of mature readers, reading at their normal rates. Passages and questions from a standardized reading test were displayed via an electromechanical device which allowed actual reading times to be recorded. 5 experimental chunked formats were compared with each other and 1 selected

Ronald P. Carver

1970-01-01

273

Desert Storm environmental effects  

Microsoft Academic Search

It is noted that after more than six months of operation of the Patriot launch station in the Saudi Arabian desert no problems that were attributed to high temperature occurred. The environmental anomalies that did occur were cosmetic in nature and related to dust and salt fog. It was concluded that the Desert Storm environmental effects were typical of worldwide

E. W. Kimball

1992-01-01

274

Desert Storm environmental effects  

NASA Astrophysics Data System (ADS)

It is noted that after more than six months of operation of the Patriot launch station in the Saudi Arabian desert no problems that were attributed to high temperature occurred. The environmental anomalies that did occur were cosmetic in nature and related to dust and salt fog. It was concluded that the Desert Storm environmental effects were typical of worldwide hot, dry climates.

Kimball, E. W.

275

Ground Effect in Flight  

Microsoft Academic Search

The present paper aims to analyze the propulsion of birds and fishes undergoing the ground effect as well as the lift of high-speed ground vehicle. Applying the analytical method which was developed for flutter of a soft plate placed at an arbitrary position in subsonic channel flows, calculations are carried out first for non-oscillatory case in compressible flow and then

Yoshimichi Tanida

2001-01-01

276

Matthew Effects for Whom?  

ERIC Educational Resources Information Center

|Which children are most at risk of experiencing a Matthew effect in reading? We investigated this question using population-based methodology. First, we identified children entering kindergarten on socio-demographic factors (i.e., gender, race/ethnicity, and socioeconomic status) known to index the relative risks and resources available to them…

Morgan, Paul L.; Farkas, George; Hibel, Jacob

2008-01-01

277

Local-Effect Games  

Microsoft Academic Search

We present a new class of games, local-effect games (LEGs), which exploit structure in a differ- ent way from other compact game representations studied in AI. We show both theoretically and em- pirically that these games often (but not always) have pure-strategy Nash equilibria. Finding a po- tential function is a good technique for finding such equilibria. We give a

Kevin Leyton-brown; Moshe Tennenholtz

2003-01-01

278

Cost Effective Buying  

NSDL National Science Digital Library

This lesson plan will help students learn to evaluate energy-related purchases in terms of cost-effectiveness. How long will it take for the new purchase to "pay for itself" in terms of energy savings? The lesson involves both sustainability and economics concepts. The lesson should take two or three class periods to complete.

2011-01-11

279

Camp's "Disneyland" Effect.  

ERIC Educational Resources Information Center

|Describes the positive mental, physical, and social growth impacts that the camping experience had on the author, and urges camp program evaluation to plan and implement such changes. Sidebar lists steps of effective evaluation: program goals and objectives, goals of evaluation, implementation of evaluation, data analysis, and findings and…

Renville, Gary

1999-01-01

280

Developing Effective Tourism Leadership  

Microsoft Academic Search

This study explores the development of effective leadership in the tourism industry from the perspective of current industry leaders in Hong Kong, China. The literature reviews the key themes in tourism leadership research, which is followed by an empirical qualitative study of 10 leaders in the tourism industry in Hong Kong. Findings are explored in relation to three key areas:

Karin Weber; Adele Ladkin

2010-01-01

281

Gauge Invariant Effective Potentials  

SciTech Connect

We make use of a dual formulation of the abelian Higgs model expressing it in terms of anti-symmetric tensor fields. In this dual form we obtain a gauge invariant derivation of the effective potential and also make the topological contributions (vortex-strings) explicit in the action.

Ramos, Rudnei O. [Departamento de Fisica Teorica, Universidade do Estado do Rio de Janeiro, 20550-013 Rio de Janeiro, RJ (Brazil); Medeiros Neto, J.F. [Departamento de Fisica, Universidade Federal do Para, 66075-110 Belem, PA (Brazil); Departamento de Fisica Teorica, Universidade do Estado do Rio de Janeiro, 20550-013 Rio de Janeiro, RJ (Brazil)

2004-12-02

282

Documentation: Effective AND Literate  

Microsoft Academic Search

The purpose of this paper is to show how documentation can be literate, in a stylistic sense, and still be effective. Literate prose is a powerful tool that, when properly used in computer documentation, can take advantage of the full power of the English language. This does not mean that all computer documentation must or can read like a Nobel

Paul S. Burdett Jr.

1985-01-01

283

Astrophysical chaotic gun effect  

Microsoft Academic Search

We propose a kinetic equation for a special kind of acceleration: chaotic gun effect. Then we infer a distribution function which can depict the instability condition. With this distribution function we derive the power spectrum of the synchrotron emission and we prove the power law form of the power spectrum. We show that the spectral index of the emission spectrum

Gheorghe Dumitrescu; Toma N. Socolescu

2009-01-01

284

Effective Internet Research.  

ERIC Educational Resources Information Center

|Describes how teachers can help students learn to use effectively the wealth of knowledge on the Internet by organizing research in advance, planning carefully and structuring assignments as students conduct their own research, and teaching students to evaluate web sites. (SR)|

Lim, Janine

2001-01-01

285

Lorenz Attractor -- Butterfly Effect  

NSDL National Science Digital Library

The "Butterfly Effect", or more technically the "sensitive dependence on initial conditions", is the essence of chaos. This is illustrated an applet of the Lorenz Attractor. The demonstration shows a graphical representation of the time variation of three variables X(t),Y(t) and Z(t), coupled by non-linear evolution equations.

Michael Cross, Cal T.

286

Effective Press Releases  

Microsoft Academic Search

Stresses the importance of the effective management of the release of information to the media and the development of media relations. Considers reasons for good and bad press. Advises on the presentation of press releases, the elements of their content and their structure. Looks at how additional information should be supplied, and how photographs can be used to illustrate a

Linda S. Ashcroft

1994-01-01

287

Stern-Gerlach effect  

NSDL National Science Digital Library

This web page illustrates the Stern-Gerlach effect on spin 1/2 particles. Movies and an illustration show the time-dependent properties of wavepackets in an inhomogeneous magnetic field. Examples are given for silver atoms, ions, and electrons.

Michielsen, Kristel; De Raedt, Hans

2010-03-11

288

Courtside: Private Effects?  

ERIC Educational Resources Information Center

After being accused of sexually harassing a student, a high school math teacher in New York was suspended with pay pending an impartial hearing. The district allowed the teacher to return to his classroom to collect his personal effects, which he had kept in boxes, desk drawers, and three filing cabinets, one of which was locked. He did not…

Zirkel, Perry A.

2004-01-01

289

Lightning Physics and Effects  

Microsoft Academic Search

Lightning Physics and Effects is not a lightning book; it is a lightning encyclopedia. Rarely in the history of science has one contribution covered a subject with such depth and thoroughness as to set the enduring standard for years, perhaps even decades, to come. This contribution covers all aspects of lightning, including lightning physics, lightning protection, and the interaction of

Richard E. Orville

2004-01-01

290

Media effect in commercial  

Microsoft Academic Search

Keywords Brand identity, Brand image, Consumer behaviour, Goodwill, Marketing communications, Sponsorship Abstract Various elements of brand identity contribute to brand image development; however, the role of marketing communications is particularly important in achieving brand image effects. In the case of advertising, two separate elements of communications, a message and a medium, combine to deliver particular brand image values. In the

David Shipley

291

Facilitating online discussions effectively  

Microsoft Academic Search

This article presents a synthesis of the theoretical and research literature on facilitating asynchronous online discussions effectively. Online courses need to be designed so that they provide motivation for students to engage in productive discussions and clearly describe what is expected, perhaps in the form of a discussion rubric. Additionally, instructors need to provide discussion forums for socio-emotional discussions that

Alfred P. Rovai

2007-01-01

292

The Energy Diameter Effect  

NASA Astrophysics Data System (ADS)

The diameter (size) effect is the well-known increase of detonation velocity with increasing radius. We ask if a similar effect is seen with the detonation energy. To see this, it is necessary to perform the Cylinder test on small-radius samples of non-ideal explosives, which detonate with a low velocity. We fired nine ammonium nitrate/aluminum and AN/NM Cylinder shots with diameters of 12.7 to 50.8 mm using Fabry and heterodyne velocimetry for the wall velocities and pins for the detonation velocity. It is the use of the ultra-narrow 12.7 mm copper cylinders that give us points low enough to be sure that the effect exists. We find that the detonation energies at the three standard Cylinder relative volumes (2.2, 4.4, 7.2) vary roughly as the square of the detonation velocity. This is confirmed in numerical simulation calculations. A simple derivation of the relations of energy, detonation velocity, reaction zone length and detonation rate are given. We define a generalized inverse radius that can be applied to data for both explosive cylinders and outwardly-detonating spheres. The relation that detonation rate is proportional to the diameter effect slope can be used to derive the inverse radius equation. This work was performed under the auspices of the U.S. Department of Energy by the University of California Lawrence Livermore National Laboratory under contract No. W-7405-Eng-48.

Vitello, Peter; Souers, P. Clark

2007-06-01

293

Recruiting Effective Board Members.  

ERIC Educational Resources Information Center

Asserts that lack of seriousness in recruiting board members for child care agencies can create problems with organizational effectiveness. Addresses the following: (1) Do we need more board members?; (2) What do we need from new members?; and (3) How do we begin recruiting? Provides resources, such as the "Child Care Agency Board Skill Inventory"…

Bess, Gary; Ratekin, Cindy

1999-01-01

294

DESIGNING EFFECTIVE STUDY ENVIRONMENTS  

Microsoft Academic Search

The study setting (private or open-plan), environmental color (blue, red, or white), and study material (reading or math comprehension) were manipulated in a simulated study environment to determine their effects on adult students' mood, satisfaction, motivation, and performance. Students rated the reading task as more demanding and less enjoyable than the math task. Negative mood was slightly greater for students

NANCY J. STONE

2001-01-01

295

Defending Double Effect  

Microsoft Academic Search

According to the doctrine of double effect(DDE), there is a morally significantdifference between harm that is intended andharm that is merely foreseen and not intended.It is not difficult to explain why it is bad tointend harm as an end (you have a ``badattitude'' toward that harm) but it is hard toexplain why it is bad to intend harm as a

Alison Hills

2003-01-01

296

Effective Instructional Management.  

ERIC Educational Resources Information Center

|Effective instructional management processes come in many guises, but all share four essential components: (1) a set of educational goals toward which progress can be measured; (2) a means of assessing students' instructional needs and determining placement and grouping; (3) an organizational structure and instructional delivery process capable…

Zakariya, Sally Banks; Steller, Arthur, Ed.

297

Evaluating Effective Supervision.  

ERIC Educational Resources Information Center

|This paper outlines the purposes, professional obligations, and key components to consider when providing effective evaluation in psychotherapy supervision. An overview of various methods for gathering supervision data for evaluation purposes is provided including self-reporting; process notes; video and audiotaping; live observation; co-therapy;…

Worthen, Vaughn E.; Dougher, M. Kirk

298

Effect of Shock Waves.  

National Technical Information Service (NTIS)

Studies of the pathogenetic effects of shock waves from explosions are reviewed. The characteristics of an air blast are described. The interaction of such a blast on the human body, and the mechanism of resulting damage are investigated with particular a...

P. I. Burenin

1974-01-01

299

Creating Effective Multimedia Instruction  

Microsoft Academic Search

English: This paper presents information on several critical themes related to multimedia instruction. An understanding of these issues will be helpful to anyone involved in the design, development or use of computer delivered instruction. Topics addressed in this paper focus on: software product life cycle; systematic approach to design; multimedia design and development teams; production values; critical components of effective

Gregory C Sales

1999-01-01

300

Marijuana: Respiratory Tract Effects.  

PubMed

Marijuana is the most commonly used drug of abuse in the USA. It is commonly abused through inhalation and therefore has effects on the lung that are similar to tobacco smoke, including increased cough, sputum production, hyperinflation, and upper lobe emphysematous changes. However, at this time, it does not appear that marijuana smoke contributes to the development of chronic obstructive pulmonary disease. Marijuana can have multiple physiologic effects such as tachycardia, peripheral vasodilatation, behavioral and emotional changes, and possible prolonged cognitive impairment. The carcinogenic effects of marijuana are unclear at this time. Studies are mixed on the ability of marijuana smoke to increase the risk for head and neck squamous cell carcinoma, lung cancer, prostate cancer, and cervical cancer. Some studies show that marijuana is protective for development of malignancy. Marijuana smoke has been shown to have an inhibitory effect on the immune system. Components of cannabis are under investigation as treatment for autoimmune diseases and malignancy. As marijuana becomes legalized in many states for medical and recreational use, other forms of tetrahydrocannabinol (THC) have been developed, such as food products and beverages. As most research on marijuana at this time has been on whole marijuana smoke, rather than THC, it is difficult to determine if the currently available data is applicable to these newer products. PMID:23715638

Owen, Kelly P; Sutter, Mark E; Albertson, Timothy E

2013-05-29

301

The Stephen Lawrence Effect.  

ERIC Educational Resources Information Center

Discusses the effect of the Macpherson Inquiry Report into the murder of Stephen Lawrence, a black man, on efforts to reduce institutional bias in Great Britain, claiming that there has been much more institutional indifference than institutional change since the report was published. Notes the need to rid society of racism in education. (SM)

Ouseley, Herman

2000-01-01

302

Loop effects in ?-->?+?-?  

NASA Astrophysics Data System (ADS)

We show that the incorporation of the model consisting of a loop of charged kaons in the description of the ?-->ƒ;0? decay has important effects on the expected signal to background ratio for e+e--->?(?)-->?+?-?. On leave of absence from Escuela Ciencias Físico-Matemáticas, Universidad Autónoma de Sinaloa.

Lucio, J. L. M.; Napsuciale, M.

1994-07-01

303

Hall Effect Spintronics.  

National Technical Information Service (NTIS)

This report results from a contract tasking Tel Aviv University as follows: This project will attempt to develop a new type of magnetic memory devices based on the so-called Extraordinary Hall Effect (EHE) in which information is stored in nanometric magn...

A. Gerber

2008-01-01

304

Towards Hall effect spintronics  

Microsoft Academic Search

Major efforts in the current exploration of spintronics are focused on the giant magnetoresistance (GMR) phenomenon in metallic, semiconducting and tunnel junction magnetic heterostructures. I wish to present a different approach based on the extraordinary Hall effect (EHE). Since its discovery more than a century ago, the EHE was not considered seriously for technological applications because of its relatively small

A. Gerber

2007-01-01

305

Effects of nuclear war  

Microsoft Academic Search

The author reviews the subject rising the following topics and subtopics: I. Nuclear explosions: heat, nuclear radiation, and radioactive fallout; II. Effects: radiation sickness, burns, blast injuries, and equivalent areas of death; III. Nuclear war: battlefield, regional, intercontinental - counterforce, and intercontinental - counter-city and industry. There are two appendices. 34 references, 32 figures.

von Hippel

1983-01-01

306

Continuous electrowetting effect  

Microsoft Academic Search

We introduce a new electrowetting effect, continuous electrowetting (CEW), and show its advantages for applications to displays and other electro-optic devices. We demonstrate experimentally, by using CEW, fast and reversible electrowetting flow on the theoretically predicted scale of ?10 cm\\/s for ?1-V driving voltage.

G. Beni; S. Hackwood; J. L. Jackel

1982-01-01

307

Building Effective Afterschool Programs.  

ERIC Educational Resources Information Center

|Through a comprehensive review of various afterschool programs across the United States, this resource provides a practical overview of the research and best practices that can be easily adapted and applied in the development of highly effective afterschool programs. chapters focus on: (1) "Why Afterschool Programs?" (benefits, challenges, and…

Fashola, Olatokunbo S.

308

Modelling tidal effects  

Microsoft Academic Search

Two models for demonstrating tides and experimenting with various tidal effects are presented. The first takes advantage of the approximately inverse-square nature of the force law for magnetic poles and exhibits symmetric tidal bulges on opposite sides of the planet, analogous to the tides of the earth. The second demonstration apparatus is a realization of the ``rubber sheet'' geometry analogy

Gary White; Tony Mondragon; David Slaughter; Dorothy Coates

1993-01-01

309

Learning to Effect.  

ERIC Educational Resources Information Center

This book presents 14 papers which discuss contemporary issues of curriculum change and instructional effectiveness in higher education primarily from a British perspective. Papers address curriculum purpose, curriculum delivery, and curriculum impact on the wider society. In addition, the book covers experiential learning, skills and training,…

Barnett, Ronald, Ed.

310

Exploring the Lotus Effect  

NSDL National Science Digital Library

Students test and observe the âself-cleaningâ lotus effect using a lotus leaf and cloth treated with a synthetic lotus-like superhydrophobic coating. They also observe the Wenzel and Cassie Baxter wetting states by creating and manipulating condensation droplets on the leaf surface. They consider the real-life engineering applications for these amazing water-repellent and self-cleaning properties.

NSF CAREER Award and RET Program, Mechanical Engineering and Material Science,

311

The Effective, Efficient Professor.  

ERIC Educational Resources Information Center

|Presents a succinct overview of the book "The Effective, Efficient Professor" (P. Wankat) that presents a wealth of strategies and techniques for successful faculty members. Sections of the book focus on time management, teaching, students, and scholarship and service. Includes some practical tips from the book ranging from instructional…

Felder, Richard M.

2002-01-01

312

On nature's scaling effects  

Microsoft Academic Search

This presentation afforded the opportunity to look back in the literature to discover scaling effects in nature that might be relevant to composites. Numerous examples were found in nature's approaches to wood, teeth, horns, leaves, eggs, feathers, etc. Nature transmits tensile forces rigidly with cohesive bonds, while dealing with compression forces usually through noncompressible hydraulics. The optimum design scaling approaches

Dick J. Wilkins

1994-01-01

313

Notes on Effective Bandwidths  

Microsoft Academic Search

This paper presents a personal view of work to date on effective bandwidths,emphasising the unifying role of the concept: as a summary of thestatistical characteristics of sources over different time and space scales;in bounds, limits and approximations for various models of multiplexingunder quality of service constraints; and as the basis for simple and robusttariffing and connection acceptance control mechanisms for

Frank Kelly

1996-01-01

314

Alexandrite effect spectropyrometer  

NASA Astrophysics Data System (ADS)

Alexandrite crystal is commonly used for making alexandrite laser, and it also has a less-known phenomenon called the alexandrite effect that refers to the color change between different light sources. A novel spectropyrometer for temperature measurement of a radiating body utilizing the alexandrite effect is introduced. The alexandrite effect method for temperature measurement is based on the relationship between the temperature of blackbody and the hue-angle in the CIELAB color space. The alexandrite effect spectropyrometer consists of an optical probe, a spectrometer, a computer, and an alexandrite filter. It measures the spectral power distribution of a radiating body through the alexandrite filter, calculates the hue-angle, and determines the temperature. The spectropyrometer is suitable for temperature measurement of any radiating body with or without spectral lines in its spectral power distribution from 1000 K to 100000 K. The spectropyrometer is particularly useful for high to ultrahigh temperature measurement of any radiating bodies with spectral line emissions, such as electric arcs and discharges, plasmas, and high temperature flames.

Liu, Yan

2006-08-01

315

Cutaneous Effects of Smoking  

Microsoft Academic Search

Background: Cigarette smoking is the single biggest preventable cause of death and disability in developed countries and is a significant public health concern. While known to be strongly associated with a number of cardiovascular and pulmonary diseases and cancers, smoking also leads to a variety of cutaneous manifestations. Objective: This article reviews the effects of cigarette smoking on the skin

Anatoli Freiman; Garrett Bird; Andrei I. Metelitsa; Benjamin Barankin; Gilles J. Lauzon

2004-01-01

316

The Contrail Effect  

NSDL National Science Digital Library

NOVA's The Contrail Effect describes how contrails form and how humidity determines how long they last. The webpage goes on to describe the study during the days of clear skies, without contrails, following 9/11. Three satellite images of contrail patterns are provided.

Foundation, Wgbh E.

2011-09-15

317

Effective family problem solving.  

PubMed

Effective family problem solving was studied in 97 families of elementary-school-aged children, with 2 definite-solution tasks--tower building (TWB) and 20 questions (TQ), and 1 indefinite-solution task--plan-something-together (PST). Incentive (for cooperation or competition) and task independence (members worked solo or jointly) were manipulated during TWB and TQ, yielding 4 counterbalanced conditions per task per family. On TQ, solo performance exceeded joint performance; on TWB, competition impaired joint performance. Families effective at problem solving in all conditions of both definite-solution tasks tried more problem-solving strategies during TWB and deliberated longer and reached more satisfactory agreements during PST. Family problem-solving effectiveness was moderately predicted by 2 parents' participation in the study. Parental education, parental occupational prestige, and membership in the family of an academically and socially competent child were weaker predictors. The results indicate that definitions of effective family problem solving that are based on directly observed measures of group interaction are more valid than definitions that rely primarily on family characteristics. PMID:3987417

Blechman, E A; McEnroe, M J

1985-04-01

318

Reading Effects of IBM's \\  

Microsoft Academic Search

This article reviews evaluations of IBM's Writing to Read program in kindergartens and first grades. In Writing to Read (WTR), students rotate through five learning stations to learn and practice phonics, to write stories, and to listen to recorded books. Two of these stations involve computers. Twenty-one studies of Writing to Read in kindergartens found a median effect size of

Robert E. Slavin

1991-01-01

319

The Placebo Effect  

Microsoft Academic Search

Placebos have been traditionally regarded as deceptive therapies and have not been understood in the broader context of social symbols and of interpersonal factors that surround the healing process itself. Although the power of inert substances to heal is well recognized, the placebo effect also influences the outcome of conventional therapies. The role of the placebo in modern medicine is

Curtis E Margo

1999-01-01

320

ENVIRONMENTAL RESIDUE EFFECTS DATABASE (ERED)  

EPA Science Inventory

US Army Corps of Engineers public web site for the "Environmental Residue Effects Database", a searchable database of adverse biological effects associated with tissue concentrations of various contaminants....

321

Adverse effects of cannabis.  

PubMed

Cannabis, Cannabis sativa L., is used to produce a resin that contains high levels of cannabinoids, particularly delta9-tetrahydrocannabinol (THC), which are psychoactive substances. Although cannabis use is illegal in France and in many other countries, it is widely used for its relaxing or euphoric effects, especially by adolescents and young adults. What are the adverse effects of cannabis on health? During consumption? And in the long term? Does cannabis predispose users to the development of psychotic disorders? To answer these questions, we reviewed the available evidence using the standard Prescrire methodology. The long-term adverse effects of cannabis are difficult to evaluate. Since and associated substances, with or without the user's knowledge. Tobacco and alcohol consumption, and particular lifestyles and behaviours are often associated with cannabis use. Some traits predispose individuals to the use of psychoactive substances in general. The effects of cannabis are dosedependent.The most frequently report-ed adverse effects are mental slowness, impaired reaction times, and sometimes accentuation of anxiety. Serious psychological disorders have been reported with high levels of intoxication. The relationship between poor school performance and early, regular, and frequent cannabis use seems to be a vicious circle, in which each sustains the other. Many studies have focused on the long-term effects of cannabis on memory, but their results have been inconclusive. There do not * About fifteen longitudinal cohort studies that examined the influence of cannabis on depressive thoughts or suicidal ideation have yielded conflicting results and are inconclusive. Several longitudinal cohort studies have shown a statistical association between psychotic illness and self-reported cannabis use. However, the results are difficult to interpret due to methodological problems, particularly the unknown reliability of self-reported data. It has not been possible to establish a causal relationship in either direction, because of these methodological limitations. In Australia, the marked increase in cannabis use has not been accompanied by an increased incidence of schizophrenia. On the basis of the available data, we cannot reach firm conclusions on whether or not cannabis use causes psychosis. It seems prudent to inform apparently vulnerable individuals that cannabis may cause acute psychotic decompensation, especially at high doses. Users can feel dependent on cannabis, but this dependence is usually psychological. Withdrawal symptoms tend to occur within 48 hours following cessation of regular cannabis use, and include increased irritability, anxiety, nervousness, restlessness, sleep difficulties and aggression. Symptoms subside within 2 to 12 weeks. Driving under the influence of cannabis doubles the risk of causing a fatal road accident. Alcohol consumption plays an even greater role. A few studies and a number of isolated reports suggest that cannabis has a role in the occurrence of cardiovascular adverse effects, especially in patients with coronary heart disease. Numerous case-control studies have investigated the role of cannabis in the incidence of some types of cancer. Its role has not been ruled out, but it is not possible to determine whether the risk is distinct from that of the tobacco with which it is often smoked. Studies that have examined the influence of cannabis use on the clinical course of hepatitis C are inconclusive. Alcohol remains the main toxic agent that hepatitis C patients should avoid. In practice, the adverse effects of low-level, recreational cannabis use are generally minor, although they can apparently be serious in vulnerable individuals. The adverse effects of cannabis appear overall to be less serious than those of alcohol, in terms of neuropsychological and somatic effects, accidents and violence. PMID:21462790

2011-01-01

322

Adverse effects of retinoids.  

PubMed

Oral retinoids, synthetic derivatives of vitamin A, have been used in the treatment of various dermatoses over the last decade. The most useful drugs have been isotretinoin (13-cis-retinoic acid) for nodulocystic acne and etretinate for psoriasis vulgaris. Retinoids are also effective in the treatment of papulosquamous dermatoses other than psoriasis (i.e. inherited disorders of keratinisation), cutaneous T-cell lymphoma and in chemotherapy and chemoprevention of cancer. However, systemic administration of these compounds is frequently associated with mucocutaneous side effects, liver toxicity and abnormalities of serum lipid profiles, which might be related to an increased risk of coronary heart disease. Of particular concern is the teratogenic effect of all retinoids, which limits their use in women of child-bearing potential. Chronic toxicities from long term therapy with retinoids may result in skeletal abnormalities, usually mimicking diffuse idiopathic hyperostosis syndrome. Furthermore, the chronic use of retinoids in children may inhibit their growth due to premature epiphyseal closure. In contrast to other side effects of retinoids which are dose dependent and reversible upon withdrawal of the drug, it seems unlikely that bone abnormalities will resolve after discontinuation of the medication. In view of the wide spectrum of toxicities, treatment with retinoids requires appropriate selection of patients, careful consideration of the benefit to risk ratio for each individual, periodic monitoring of clinical response and laboratory tests. Clinicians should use special management techniques in order to prevent or minimize slide effects. Extensive investigations are currently being conducted in an attempt to develop new retinoids which will improve the therapeutic efficacy and reduce unwanted reactions. PMID:3054426

David, M; Hodak, E; Lowe, N J

323

Advanced heat-pipe heat exchanger and microprocessor-based modulating burner controls development. Annual report, January-December 1986  

Microsoft Academic Search

The work presented in the report includes: (1) the development of a heat-pipe condensing heat exchanger; (2) the development of a nominal 100,000-Btu\\/hr modulating air\\/gas valve and (3) performance studies of a water\\/copper thermosyphon. The condensing heat exchanger uses ten water copper thermosyphons that are msnifolded at both the condenser and evaporator ends to achieve a low-cost, compact design. This

A. Lowenstein; B. Cohen; S. Feldman; M. Spatz; E. Smith

1987-01-01

324

Advanced heat-pipe heat exchanger and microprocessor-based modulating burner controls development. Annual report, January 1985January 1986  

Microsoft Academic Search

The development of a novel condensing heat exchanger, a modulating gas burner, and a zone-controlled residential warm-air heating system is described. The condensing heat exchanger uses ten thermosyphons manifolded at both the condenser and evaporator ends to achieve a compact low-cost design. Initial tests have demonstrated a +92-% steady-state efficiency for a conventional clamshell furnace operating with the thermosyphon heat

A. Lowenstein; B. Cohen; S. Feldman; M. Spatz; E. Smith

1986-01-01

325

The Effects of Procedural Variations on Lateralized Stroop Effects  

Microsoft Academic Search

Several issues in the classic Stroop effect remain open, including (i) the stage of processing which gives rise to the effect, (ii) the effect of some procedural manipulations, (iii) the effect of hemispheric specialization and of interhemispheric interactions, and (iv) the existence of individual differences. In this paper, we investigate these issues using a series of experiments with central, lateral,

N. Y. Weekes; E. Zaidel

1996-01-01

326

Cerebroprotective effect of flunarizine.  

PubMed

The cerebroprotective effect of flunarizine was studied using the following methods: hypobaric hypoxia in mice, complete ischemia by decapitation in mice, anoxic hypoxia in mice, hemic hypoxia in rats, incomplete ischemia by bilateral carotid ligation in rats and asphyxic hypoxia in cats. Piracetam, meclofenoxate, nicergoline, naftidrofuryl, cinnarizine and nifedipine were studied as reference drugs. Flunarizine increased the survival time in all survival models. Its effect was most pronounced in complete ischemia model, and considerably higher than that of reference drugs. In asphyxic hypoxia flunarizine increased cortical resistance and shortened cortical recovery. The EEG frequency-amplitude analysis during asphyxic hypoxia showed a significant decrease of the slow-waves amplitudes of delta and theta range, and an increase of the fast-waves amplitudes of beta-2 range, changes indicating protective action. PMID:2087140

Nikolov, R; Nikolova, M; Dikova, M; Mirzoyan, R S; Ganshina, T S; Volobueva, T I

327

Doppler Effect Model  

NSDL National Science Digital Library

The Doppler Effect model demonstrates the shift in frequency of a wave that is produced by the motion of either the wave source or the observer of the wave (or both). In this simulation, you can explore the change in the wave that is produced by source and/or observer motion, and you can even view what the situation looks like from the perspective of the medium (the standard reference frame), the source, or the observer. The Doppler Effect model was created using the Easy Java Simulations (EJS) modeling tool. It is distributed as a ready-to-run (compiled) Java archive. Double clicking the ejs_bu_Doppler.jar file will run the program if Java is installed.

Duffy, Andrew

2010-04-25

328

Radiation Damage Effects  

NASA Astrophysics Data System (ADS)

Radiation damage is an important issue for the particle detectors operated in a hostile environment where radiations from various sources are expected. This is particularly important for high energy physics detectors designed for the energy and intensity frontiers. This chapter describes the radiation damage effects in scintillating crystals, including the scintillation-mechanism damage, the radiation-induced phosphorescence, and the radiation-induced absorption. The radiation damage mechanism in crystal scintillators is also discussed. While the damage in halides is attributed to the oxygen/hydroxyl contamination, it is the structure defects, such as the oxygen vacancies, which cause the damage in oxides. Various material analysis methods used in investigations of the radiation damage effects as well as the improvement of crystal quality through systematic R&D are also presented.

Zhu, R.-Y.

329

The QCD Effective String  

NASA Astrophysics Data System (ADS)

QCD can be described in a certain kinematical regime by an effective string theory. This string must couple to background chiral fields in a chirally invariant manner, thus taking into account the true chirally non-invariant QCD vacuum. By requiring conformal symmetry of the string and the unitarity constraint on chiral fields we reconstruct the equations of motion for the latter ones. These provide a consistent background for the propagation of the string. By further requiring locality of the effective action we recover the Lagrangian of non-linear sigma model of pion interactions. The prediction is unambiguous and parameter-free. The estimated chiral structural constants of Gasser and Leutwyler fit very well the phenomenological values.

Espriu, Domenec

2003-10-01

330

Applications of effective Lagrangians  

SciTech Connect

This thesis contains some applications of effective field theories in particle physics. The impact of a fourth generation of quarks on neutral kaon mixing is considered, and the results are extended to the mixing and CP violating phenomenology of neutral bottom meson systems. A phenomenological Lagrangian is constructed to describe radiative vector meson decays. The measured decay rates are reproduced, and one prediction is made. It is shown that the large-N approximation in the standard model cannot explain the {Delta}I = {1/2} rule for kaon nonleptonic decays, even when short distance effects such as Penguins are included. Finally, the contribution of small instantons to the axion potential is calculated. The induced potential can be a large if the QCD coupling is non-decreasing at high energies, and if a suppression by light quark masses can be avoided using loops of scalars.

Flynn, J.M.

1987-01-01

331

Developmental effects of dioxins.  

PubMed Central

The potent developmental toxicity of dioxin in multiple species has been known for a number of years. However, recent studies have indicated that dioxin also induces functional developmental defects, many of which are delayed. Subtle structural deficits, not detectable at birth, have also been described in multiple species and in both sexes. Certain defects have been reported not only in animals but also in children prenatally exposed to complex mixtures containing dioxinlike compounds. None of the effects can be attributed to modulation of any one endocrine system. For example, dioxin does not bind to the estrogen receptor, but it can cause effects that are both estrogenic and antiestrogenic. However, viewing dioxin and related compounds as endocrine disruptors that may alter multiple pathways sheds some light on the complexities of this potent class of growth dysregulators.

Birnbaum, L S

1995-01-01

332

Fire Effects Information System  

NSDL National Science Digital Library

The Fire Effects Information System (FEIS) provides up-to-date information about fire effects on plants and animals. It was developed at the USDA Forest Service Rocky Mountain Research Station's Fire Sciences Laboratory in Missoula, Montana. The FEIS database contains synoptic descriptions, taken from current English-language literature of almost 900 plant species, about 100 animal species, and 16 Kuchler plant communities found on the North American continent. The emphasis of each synopsis is fire and how it affects each species. Background information on taxonomy, distribution, basic biology and ecology of each species is also included. Synopses are thoroughly documented, and each contains a complete bibliography. Personnel from several land management agencies (USDA Forest Service, USDI-BIA, NPS, BLM, F&WS) identified the species to be included in the database. Those agencies funded the original work and continue to support maintenance and updating of the database.

1995-12-12

333

Health effects of ozone  

SciTech Connect

It is an honor to have the opportunity to comment on Dr. Morton Lippmann's excellent review on the health effects of ozone, which was presented at the 82nd Air and Waste Management Association Annual Meeting and Exhibition held in Anaheim, California in June 1989. It is comprehensive in citing all of the pertinent references, interpretative in its review of the literature, integrates critical information and is highly relevant in dealing with one of our nation's most difficult air pollution issues. I commend Dr. Lippmann for developing a critical review that serves in many ways as a case study in toxicology and risk assessment. It does this by integrating data obtained from various types of studies, emphasizing exposure-dose-response relations and underscoring the importance of understanding the mechanisms by which ozone produces health effects. In this commentary, I would like to briefly consider several of the points made by Lippmann, and in doing so, note various issues requiring additional research.

McClellan, R.O. (Chemical Industry Institute of Toxicology, Research Triangle Park, NC (USA))

1989-09-01

334

[Hypertensive effects of qat].  

PubMed

Chewing of Qat leaves which contain amphetamine alkaloids is a traditional drug practice in the horn of Africa. Cathine and cathinone are responsible for the desired psychogenic (suppression of hunger, mind stimulation, euphoria) and sympathicomimetic effects. In this study, we monitored seven volunteers during a traditional qat ritual. An increase in systolic and diastolic pressure was observed in three patients including one presenting predisposing chronic arterial hypertension. Peak pressure was observed approximately seven hours after beginning the ritual. The three patients presenting pressure changes were not significantly different from the four unaffected patients with regard to age or duration of qat use. These findings suggest that qat use by untreated hypertensive patients who react strongly to vasoconstrictive effects can lead to hypertension and resulting cardiovascular complications. PMID:10088104

Mion, G; Oberti, M; Ali, A W

1998-01-01

335

Evaluating Grandmother Effects  

PubMed Central

Women who have outlived child-bearing have long been described as post-reproductive. But contributions they make to the survival or fertility of their descendants enhance the reproduction of their genes. Consequently natural selection affects this characteristic stage of human life history. Grandmother effects can be measured in data sets that include births and deaths over several generations, but unmeasured covariates complicate the task. Here we focus on two complications: cohort shifts in mortality and fertility, and maternal age at death. We use the Utah Population Database to show that longevity of grandmothers may be associated with fewer grandchildren, as reported by Madrigal and Melendez-Obando (2008) for a Costa Rican sample, even when grandmother effects are actually positive.

Smith, Ken R.

2009-01-01

336

Nonopioid effect of ?-endorphin.  

PubMed

This review presents the generalized literature data and the results of our own research of the nonopioid effect of ?-endorphin, an opioid neuropeptide interacting not only with opioid but also with nonopioid (insensitive to the opioid antagonist naloxone) receptors. The roles of the hormone and its receptors in regulation of the immune, nervous, and endocrine systems are discussed. The effect of neuromediator on the immune system mediated by both opioid and nonopioid receptors is considered in detail. The data on distribution and function of the nonopioid ?-endorphin receptor in human and animal organisms are presented. All available data on the characteristics of the nonopioid ?-endorphin receptor obtained by means of radioligand analysis are given. The discussed information is supposed to extend our conceptions of the role of ?-endorphin in mammals and to be of extensive use in medicine and pharmacology. PMID:21585314

Kovalitskaya, Yu A; Navolotskaya, E V

2011-04-01

337

[Herbs and cardiotoxic effects].  

PubMed

Accidental or deliberate ingestion of poisonous herbs has become an increasingly common phenomenon over the last years. From existing literature data and case reports from emergency room visits or poison control centers, an overview is presented of the potential cardiotoxic manifestations following intoxication by wild herbal plants of the territory. The effects of the consumption of cardiac glycoside-containing plants (e.g., digitalis) are discussed along with tachyarrhythmias induced by Aconitum napellus L., Atropa belladonna L., Mandragora officinarum L. or Ephedra distachya L. herbs, and hypertensive crises associated with licorice abuse. For each plant, a brief historical and botanical background is provided, focusing on pathophysiology of intoxication and cardiotoxic effects on the basis of the most recent literature. Finally, medical management of intoxication, from both a general and cardiological viewpoint, is reviewed. PMID:23748541

Maffè, Stefano; Paffoni, Paola; Laura Colombo, Maria; Davanzo, Franca; Dellavesa, Pierfranco; Cucchi, Lorenzo; Zenone, Franco; Paino, Anna Maria; Franchetti Pardo, Nicolò; Bergamasco, Luca; Signorotti, Fabiana; Parravicini, Umberto

2013-06-01

338

Spin Hall effect devices.  

PubMed

The spin Hall effect is a relativistic spin-orbit coupling phenomenon that can be used to electrically generate or detect spin currents in non-magnetic systems. Here we review the experimental results that, since the first experimental observation of the spin Hall effect less than 10 years ago, have established the basic physical understanding of the phenomenon, and the role that several of the spin Hall devices have had in the demonstration of spintronic functionalities and physical phenomena. We have attempted to organize the experiments in a chronological order, while simultaneously dividing the Review into sections on semiconductor or metal spin Hall devices, and on optical or electrical spin Hall experiments. The spin Hall device studies are placed in a broader context of the field of spin injection, manipulation, and detection in non-magnetic conductors. PMID:22522638

Jungwirth, Tomas; Wunderlich, Jörg; Olejník, Kamil

2012-04-23

339

Relativistic Hall effect.  

PubMed

We consider the relativistic deformation of quantum waves and mechanical bodies carrying intrinsic angular momentum (AM). When observed in a moving reference frame, the centroid of the object undergoes an AM-dependent transverse shift. This is the relativistic analogue of the spin-Hall effect, which occurs in free space without any external fields. Remarkably, the shifts of the geometric and energy centroids differ by a factor of 2, and both centroids are crucial for the Lorentz transformations of the AM tensor. We examine manifestations of the relativistic Hall effect in quantum vortices and mechanical flywheels and also discuss various fundamental aspects of this phenomenon. The perfect agreement of quantum and relativistic approaches allows applications at strikingly different scales, from elementary spinning particles, through classical light, to rotating black holes. PMID:22540559

Bliokh, Konstantin Y; Nori, Franco

2012-03-21

340

Lightning Physics and Effects  

NASA Astrophysics Data System (ADS)

Lightning Physics and Effects is not a lightning book; it is a lightning encyclopedia. Rarely in the history of science has one contribution covered a subject with such depth and thoroughness as to set the enduring standard for years, perhaps even decades, to come. This contribution covers all aspects of lightning, including lightning physics, lightning protection, and the interaction of lightning with a variety of objects and systems as well as the environment. The style of writing is well within the ability of the technical non-expert and anyone interested in lightning and its effects. Potential readers will include physicists; engineers working in the power industry, communications, computer, and aviation industries; atmospheric scientists; geophysicists; meteorologists; atmospheric chemists; foresters; ecologists; physicians working in the area of electrical trauma; and, lastly, architects. This comprehensive reference volume contains over 300 illustrations, 70 tables with quantitative information, and over 6000 reference and bibliography entries.

Orville, Richard E.

2004-03-01

341

Natural convection heat exchangers for solar water heating systems. Technical progress report, February 1, 1996--March 31, 1996  

SciTech Connect

This progress report describes the thermodynamic testing and modeling of a thermosyphon heat exchanger used in solar water heating systems. Testing of a four tube-in-shell thermosyphon heat exchanger was performed in two parts. The first portion of the test increased the collector fluid while the storage tank remained isothermal. After the collector fluid temperature was raised to 95 C, the second part of the test allowed the storage tank to gain heat. The test was performed for two collector flow rates. Measured values included collector side forced flow rate, temperature differences across the heat exchanger, vertical temperature distribution in the storage tank, vertical water temperature profile in the heat exchanger, and pressure drop on the thermosyphon side of the heat exchanger. The overall heat transfer coefficient-area product (UA) values obtained confirmed that models which assume UA depends solely on thermosyphon flow rate do not adequately characterize thermosyphon heat exchangers. This is because heat transfer in thermosyphon exchangers occurs in the mixed convection, rather than forced flow, regime. A linear regression equation was developed to better predict UA using the Prandtl, Reynolds, and Grashof numbers and dimensionless parameters based on fluid properties calculated for the average hot and cold leg temperatures. 9 figs.

Davidson, J.H.

1998-06-01

342

Temporary Retinal Effects  

Microsoft Academic Search

IN your present week's ``Notes'' you have referred to the curious experiences of MM. Macé de Lepinay and Nicati, in finding the town lights appear green, after five hours among snow-fields. On the Cima di Jazi, some 16,000 feet or more high, I found another effect. On removing my blue snow-glasses, the sky (at about 10 a.m.) appeared of the

J. Rand Capron

1882-01-01

343

Adipokine Effects on Bone  

Microsoft Academic Search

The adipocyte is an important source of factors that act as circulating regulators of bone metabolism. These include estrogens,\\u000a and the adipokines, leptin, resistin, adiponectin, and probably others. Leptin acts directly on bone cells, and in some experimental\\u000a models these effects are modified by its actions on the central nervous system, which impact on appetite, body weight, and\\u000a insulin sensitivity.

Ian R. Reid; J. B. Richards

2009-01-01

344

Ivabradine: Cardiovascular Effects  

Microsoft Academic Search

Ivabradine (a compound of the benzocyclobutane) is a highly selective If current inhibitor acting directly on the sino-atrial node, induces a rapid, sustained and dose-dependent reduction of heart rate at rest and during exercise without a significant effect on atrio-ventricular conduction, left ventricular contraction\\/relaxation or vascular tissues. These properties associated with an improvement in left ventricular loading related to bradycardia

Andrea Rognoni; Marzia Bertolazzi; Sergio Maccio; Giorgio Rognoni

2009-01-01

345

NEUROPROTECTIVE EFFECTS OF CURCUMIN  

Microsoft Academic Search

Neurodegenerative diseases result in the loss of functional neurons and synapses. Although future stem cell therapies offer\\u000a some hope, current treatments for most of these diseases are less than adequate and our best hope is to prevent these devastating\\u000a diseases. Neuroprotective approaches work best prior to the initiation of damage, suggesting that some safe and effective\\u000a prophylaxis would be highly

Greg M. Cole; Bruce Teter; Sally A. Frautschy

346

Local-Effect Games  

Microsoft Academic Search

Abstract We present a new class of games, local-effect games (LEGs), which exploit structure in a different way from other compact,game,representations studied in AI. We show both theoretically and empirically that these games,often (but not always) have pure-strategy Nash equilibria. Finding a potential function is a good technique for finding such equilibria. We give a complete,characterization of which LEGs have

Kevin Leyton-brown; Moshe Tennenholtz

2005-01-01

347

Neuroprotective effects of creatine  

Microsoft Academic Search

There is a substantial body of literature, which has demonstrated that creatine has neuroprotective effects both in vitro\\u000a and in vivo. Creatine can protect against excitotoxicity as well as against ?-amyloid toxicity in vitro. We carried out studies\\u000a examining the efficacy of creatine as a neuroprotective agent in vivo. We demonstrated that creatine can protect against excitotoxic\\u000a lesions produced by

M. Flint Beal

2011-01-01

348

Center for Effective Organizations  

Microsoft Academic Search

ABSTRACT In this chapter, we closely examine one set of factors that are critical for knowledge work team effectiveness --how organizations set and communicate,direction for teams. The variables we examine encompass,several related elements in the organization's direction-setting context: the clarity of the organization's strategy, the alignment of individual team, and organizational goals, and the measurability and specificity of those goals.

JAY R. GALBRAITH; SUSAN G. COHEN; CRISTINA B. GIBSON; JULIAN BIRKINSHAW

349

The reverse Stroop effect  

Microsoft Academic Search

In classic Stroop interference, manual or oral identification of sensory colors presented as incongruent color words is delayed\\u000a relative to simple color naming. In the experiment reported here, this effect was shown to all but disappear when the response\\u000a was simply to point to a matching patch of color. Conversely, strong reverse Stroop interference occurred with the pointing\\u000a task. That

Frank H. Durgin

2000-01-01

350

Writing Effective TAFs  

NSDL National Science Digital Library

This module provides an overview of some of the applicable TAF Amendment and Conditional Group usage rules, as presented in the latest version of the National Weather Service Instruction 10-813 on TAF directives. It also presents a methodology for TAF writing and development that will lead to an effective and user-friendly product. The focus is on the ceiling and visibility aspects of the TAF. This module is part of the Distance Learning Course 1: Forecasting Fog and Low Stratus

Spangler, Tim

2003-06-28

351

Side effects of benoxaprofen  

Microsoft Academic Search

A study was made of adverse dermatological reactions to the non-steroidal anti-inflammatory agent benoxaprofen. Photosensitivity was seen in several patients, confined to wavelengths less than 340 nm. Other cutaneous side effects were erythema multiforme, the Stevens-Johnson syndrome, milia, and onycholysis. One case of pancytopenia and toxic epidermal necrolysis was reported. patients were not rechallenged with the drug, but these reactions

Brian Diffey; Colin Hindson; F Lawlor

1982-01-01

352

Asking Effective Questions  

NSDL National Science Digital Library

This 8-page monograph offers strategies for effective questioning that engages students and that deepens their conceptual understanding in mathematics. It suggests questions and prompts that help students progress through various stages of the problem solving process and that help teachers assess the thinking of students. The article describes the purposes of questions at different stages of a lesson and describes situations when it is appropriate to convey information to students. A list of references is included.

2011-07-01

353

Antithyroid effects of lithium  

PubMed Central

Lithium has been reported to be goitrogenic when used for the treatment of manic-depressive psychosis. To investigate the effects of lithium on iodine metabolism, male Sprague-Dawley rats were placed on a low iodine (LID) or normal iodine diet (NID) containing enough Li2CO3 to give serum lithium levels of 0.23-0.86 mEq/liter (human therapeutic range is 0.6-1.6 mEq/liter). The following effects were noted with lithium treatment: (a) thyroid weight increased concomitant with a slowing of thyroidal iodine release; (b) the ability to concentrate iodide was increased only after goiters were established; (c) on the LID, 131I uptake was elevated throughout all phases of treatment, even when the release rate was normal; (d) iodine organification was unaffected but the proportion of 131I present as iodothyronines was decreased; (e) the thyroidal 127I content was increased; (f) despite these changes, the serum PBI remained normal as did the thyroxine turnover rate; and (g) thyrotropin (TSH) levels in serum were the same as controls except for a slight elevation early in the course of treatment; TSH levels did not correlate with goitrogenesis. When LiCl was injected in large doses into intact rats (giving serum lithium levels of 3.08-3.89 mEq/liter), the iodide concentrating mechanism, 131I uptake, and 131I release rates were depressed. Similar experiments in hypophysectomized rats receiving TSH demonstrated these to be local antithyroid effects not mediated through the pituitary. The discrepancy between acute and chronic responses to lithium, and the dissociation between the inhibition of iodine release and stimulatory effects is discussed.

Berens, S. C.; Bernstein, R. S.; Robbins, J.; Wolff, J.

1970-01-01

354

Antithyroid effects of lithium.  

PubMed

Lithium has been reported to be goitrogenic when used for the treatment of manic-depressive psychosis. To investigate the effects of lithium on iodine metabolism, male Sprague-Dawley rats were placed on a low iodine (LID) or normal iodine diet (NID) containing enough Li(2)CO(3) to give serum lithium levels of 0.23-0.86 mEq/liter (human therapeutic range is 0.6-1.6 mEq/liter). The following effects were noted with lithium treatment: (a) thyroid weight increased concomitant with a slowing of thyroidal iodine release; (b) the ability to concentrate iodide was increased only after goiters were established; (c) on the LID, (131)I uptake was elevated throughout all phases of treatment, even when the release rate was normal; (d) iodine organification was unaffected but the proportion of (131)I present as iodothyronines was decreased; (e) the thyroidal (127)I content was increased; (f) despite these changes, the serum PBI remained normal as did the thyroxine turnover rate; and (g) thyrotropin (TSH) levels in serum were the same as controls except for a slight elevation early in the course of treatment; TSH levels did not correlate with goitrogenesis. When LiCl was injected in large doses into intact rats (giving serum lithium levels of 3.08-3.89 mEq/liter), the iodide concentrating mechanism, (131)I uptake, and (131)I release rates were depressed. Similar experiments in hypophysectomized rats receiving TSH demonstrated these to be local antithyroid effects not mediated through the pituitary. The discrepancy between acute and chronic responses to lithium, and the dissociation between the inhibition of iodine release and stimulatory effects is discussed. PMID:4194189

Berens, S C; Bernstein, R S; Robbins, J; Wolff, J

1970-07-01

355

The Kaye effect  

NASA Astrophysics Data System (ADS)

The International Young Physicists' Tournament (IYPT) is a worldwide, annual competition for secondary school students. This is our solution to problem number 10, The Kaye effect, as presented in the final round of the 21st IYPT in Trogir, Croatia. The Kaye effect occurs when a thin stream of shampoo or a different adequate non-Newtonian liquid is poured onto a surface. Suddenly, a jet leaves the heap that is formed by the shampoo and begins to 'dance' around the primary jet like a lasso. The phenomenon ends when the 'dancing' jet hits the primary jet and subsequently collapses. We started our investigations based on available literature (Kaye 1963 Nature 197 1001, Versluis et al 2006 J. Stat. Mech., Collyer and Fischer 1976 Nature 261 682). We made experiments with a similar experimental set-up in which we could determine the velocities of both shampoo streams as well as the angle of the 'dancing' stream. From there on, we developed a theoretical model for the energy loss of the jet in the heap. We discovered that the air layer between the jet and the heap is a necessity for the Kaye effect to occur. At this point, our observations differ from the aforementioned literature. This also accounts for the shampoo beam acting as a light guide. Further experiments concerning the viscoelasticity of the shampoo revealed that the elastic property of the shampoo is necessary for the effect to occur. This article is a written version of the oral contribution of the German team to the 21st IYPT competition, which was awarded first prize by an international jury. The article has been edited by European Journal of Physics.

Binder, J. M.; Landig, A. J.

2009-11-01

356

Effective Teaching with Technology  

Microsoft Academic Search

A course entitled effective teaching with technology (ETT) has been taught to PhD candidates and postdoctoral students in science, technology, engineering, and mathematics (STEM) during the Spring semester of 2004, 2005, and 2006, at the University of Wisconsin-Madison. The course is supported by the NSF-sponsored Center for Integration of Research, Teaching, and Learning (CIRTL). The course employs the three CIRTL

Gregory Moses; Barbara Ingham; Katherine Barnicle; Jake Blanchard; Jan Cheetham; Sandra Courter; Elizabeth DeVos; Margaret Immendorf; Michael Litzkow; Gina Svarovsky; Alan Wolf

2006-01-01

357

Doppler-Effect Omnirange  

Microsoft Academic Search

This paper describes an omnirange of a new design in which the transmitting antenna is caused either to move, or to appear to move along a circular path to produce low-deviation FM by Doppler effect. The FM envelope phase of the transmitted signal is directionally characterized. Deviation-expansion and selective-degeneration in an AFC circuit are used at the receiver to detect

Paul Hansel

1953-01-01

358

Botany: floral fluorescence effect.  

PubMed

The way flowers appear to insects is crucial for pollination. Here we describe an internal light-filtering effect in the flowers of Mirabilis jalapa, in which the visible fluorescence emitted by one pigment, a yellow betaxanthin, is absorbed by another, a violet betacyanin, to create a contrasting fluorescent pattern on the flower's petals. This finding opens up new possibilities for pollinator perception as fluorescence has not previously been considered as a potential signal in flowers. PMID:16163341

Gandía-Herrero, Fernando; García-Carmona, Francisco; Escribano, Josefa

2005-09-15

359

Quantum effects in biology  

Microsoft Academic Search

The idea that quantum-mechanical phenomena can play nontrivial roles in biology has fascinated researchers for a century. Here we review some examples of such effects, including light-harvesting in photosynthesis, vision, electron- and proton-tunneling, olfactory sensing, and magnetoreception. We examine how experimental tests have aided this field in recent years and discuss the importance of developing new experimental probes for future

Graham R. Fleming; Gregory D. Scholes; Yuan-Chung Cheng

2011-01-01

360

Cost-Effectiveness Analyses  

Microsoft Academic Search

Surgical research has traditionally focused on comparing health outcome measures of a new technique with accepted practice.\\u000a As health care resources become scarcer and options for newer, more expensive diagnostic tests and surgical interventions\\u000a increase, incorporating cost-effectiveness analysis (CEA) into surgical research studies becomes increasingly important. CEA\\u000a provides the information necessary to allow resource allocation decisions to be based on

Lynn Stothers

361

Hall Effect Measurements  

NSDL National Science Digital Library

The objective of this Web site is twofold: (1) to describe the Hall measurement technique for determining the carrier density and mobility in semiconductor materials and (2) to initiate an electronic interaction forum where workers interested in the Hall effect can exchange ideas and information. It includes an introductory description of the Hall measurement technique and covers basic principles, equipment, and recommended procedures. Keywords: Conductance, conductivity, resistance, resistivity

2012-07-26

362

Tasting edge effects  

NASA Astrophysics Data System (ADS)

We show that the baking of potato wedges constitutes a crunchy example of edge effects, which are usually demonstrated in electrostatics. A simple model of the diffusive transport of water vapor around the potato wedges shows that the water vapor flux diverges at the sharp edges in analogy with its electrostatic counterpart. This increased evaporation at the edges leads to the crispy taste of these parts of the potatoes.

Bocquet, Lydéric

2007-02-01

363

Designing effective instruction  

Microsoft Academic Search

Summary  We have usedDesigning Effective Instruction in introductory ID courses and experienced its use from both the instructors' and the learners' perspective. Our overall\\u000a conclusion is that it is highly usable and accessible to beginning ID students, including those whose first language may not\\u000a be English. The ID model presented is clear and the focus on the learner throughout is appropriate

Gary J. Anglin; Steven M. Ross; Jerrold E. Kemp

2002-01-01

364

Preattentive auditory context effects  

Microsoft Academic Search

The effects of auditory context on the preattentive and perceptual organization of tone sequences were investigated. Two sets\\u000a of experiments were conducted in which the pitch of contextual tones was varied, bringing about two different contextual manipulations.\\u000a Preattentive auditory organization was indexed by the mismatch negativity event-related potential, which is elicited by violations\\u000a of auditory regularities even when participants ignore

István Winkler; Elyse Sussman; Mari Tervaniemi; János Horváth; Walter Ritter; Risto Näätänen

2003-01-01

365

Phenotypic Effects of the \\  

Microsoft Academic Search

From outbred Hsd:ICR mice, we selectively bred 4 replicate lines for high running (High-Runner (HR) lines) on wheels while maintaining 4 nonselected lines as controls (C lines). An apparent Mendelian recessive, the ''mini-muscle'' (MM) allele, whose main phenotypic effect is to reduce hindlimb muscle mass by 50%, was discovered in 2 HR lines and 1 C line. This gene of

ROBERT M. HANNON; S COTT A. KELLY; K EVIN M. MIDDLETON; E. M. Kolb; D ANIEL POMP; THEODORE GARLAND JR

2008-01-01

366

Radiation effects on integrated microcircuits  

NASA Astrophysics Data System (ADS)

A theory describing the effects of ionizing radiation on integrated microcircuits is developed. The features of secondary ionization effects (e.g., radiation-induced secondary breakdown) are examined along with residual and transient ionization effects on the characteristics of standard components of digital and analog ICs. The radiation characteristics of LSI systems are also considered, with emphasis on microdosimetric and functional effects.

Agakhanian, Tatevos M.; Astvatsatur'ian, Evgenii R.; Skorobogatov, Petr K.

367

SOLAR EFFECTS ON BUILDING DESIGN.  

ERIC Educational Resources Information Center

|A REPORT OF A PROGRAM HELD AS PART OF THE BUILDING RESEARCH INSTITUTE 1962 SPRING CONFERENCE ON THE SOLAR EFFECTS ON BUILDING DESIGN. TOPICS DISCUSSED ARE--(1) SOLAR ENERGY DATA APPLICABLE TO BUILDING DESIGN, (2) THERMAL EFFECTS OF SOLAR RADIATION ON MAN, (3) SOLAR EFFECTS ON ARCHITECTURE, (4) SOLAR EFFECTS ON BUILDING COSTS, (5) SELECTION OF…

Building Research Inst., Inc., Washington, DC.

368

Petroleum effects in the Arctic  

Microsoft Academic Search

This book presents papers on the environmental and biological effects of oil spills. Topics considered include the Arctic marine ecosystem, the physical and chemical fate of spilled oil, the effects of hydrocarbons on microorganisms and petroleum biodegradation in arctic ecosystems, the effects of oil on arctic invertebrates, the effects of oil on fish, a risk assessment of oil on arctic

Engelhardt

1985-01-01

369

[Biological effects of selenium].  

PubMed

The role of selenium concerning its biological effects particularly in relation to cardiovascular and tumor diseases has been in the focus of intensive studies. Selenium is a constituent part of the enzyme glutathion peroxidase (E.C.1.11.1.9) which catalyzes the conversion of hydrogen peroxide and organic hydroperoxides into water and corresponding alcohols. A review of epidemiological studies is presented focusing predominantly on countries where a low concentration of selenium in blood serum was found. The role of selenium in the etiology of cardiovascular diseases may probably be accounted for by its protective effect as it prevents platelet aggregation and protects the arterial endothelium from being damaged by lipid peroxides. The results of experimental studies, carried out in research institutes in many parts of the world, suggest that coordinated supplementation of food with selenium may reduce the risk of cancer and moreover, the effect of selenium can be modified by other dietary factors, such as vitamin A and E. (Fig. 2, Ref. 29.) PMID:1296855

Brtková, A

1992-12-01

370

Ejs Doppler Effect Model  

NSDL National Science Digital Library

The Ejs Doppler Effect model displays the detection of sound waves from a moving source and the change in frequency of the detected wave via the Doppler effect. In addition to the wave fronts from the source a graph depicting the time of emission and time of detection of each of the wave fronts is given. The speed of sound, the velocity of the source and the position and velocity of the detector can be changed via text boxes. You can modify this simulation if you have Ejs installed by right-clicking within the plot and selecting âOpen Ejs Modelâ from the pop-up menu item. Ejs Doppler Effect model was created using the Easy Java Simulations (Ejs) modeling tool. It is distributed as a ready-to-run (compiled) Java archive. Double clicking the ejs_ehu_waves_doppler.jar file will run the program if Java is installed. Ejs is a part of the Open Source Physics Project and is designed to make it easier to access, modify, and generate computer models. Additional Ejs models for wave optics are available. They can be found by searching ComPADRE for Open Source Physics, OSP, or Ejs.

Aguirregabiria, Juan

2008-08-20

371

Cascading Effects Following Intervention  

PubMed Central

Four different sources for cascade effects were examined using 9-year process and outcome data from a randomized controlled trial (RCT) of a preventive intervention using Parent Management Training – Oregon Model (PMTO™). The social interaction learning (SIL) model of child antisocial behavior serves as one basis for predicting change. A second source addresses the issue of comorbid relationships among clinical diagnoses. The third source, collateral changes, describes events in which changes in one family member correlate with changes in another. The fourth component is based on the long-term effects of reducing coercion and increasing positive interpersonal processes within the family. New findings from the 9-year follow-up show that mothers experienced benefits as measured by standard of living (i.e., income, occupation, education, and financial stress) and frequency of police arrests. It is assumed that PMTO reduces the level of coercion, which sets the stage for a massive increase in positive social interaction. In effect, PMTO alters the family environment and thereby opens doors to healthy new social environments.

Patterson, Gerald R.; Forgatch, Marion S.; DeGarmo, David S.

2010-01-01

372

Health effects of ozone  

SciTech Connect

Dr. Morton Lippmann prepared, at the request of the A WMA Review Committee, an extensive update of the available information on the biological effects of ozone. His review is a thorough and well-written summary of what is known about respiratory effects of low ozone concentrations. The authors is well qualified to evaluate clinical data on ozone effects since a substantial amount of work on this subject has been produced in his own laboratory. Years of experience in consultative functions for the Environmental Protection Agency and Clean Air Science Advisory Committee further characterize Dr. Lippmann as an especially qualified scientist for assessing this complex problem. For the same reasons, however, interpretation of some experimental data in the review may have been influenced by inherent personal biases of the author and may, in fact, differ from the views of other investigators. This possibility is recognized in the text and does not diminish the overall quality of the review. My comments will be limited primarily to the general aspects of the review and to the role of the current form of the standard in public health protection.

Vostal, J.J. (General Motors Environmental Activities Staff, Warren, MI (USA))

1989-09-01

373

Pairing correlations and effective mass  

SciTech Connect

We study the effect of effective mass on pairing correlations in the ground states of superfluid nuclei {sup 124}Sn and {sup 136}Sn. Various parameter sets of Skyrme interactions and relativistic Lagrangians are adopted to study pairing correlations across a wide range of effective mass. It is shown that surface-type pairing interaction gives an almost constant pairing gap as a function of the effective mass, while volume-type pairing interaction shows rather strong dependence of the pairing gap upon the effective mass. The local pair potentials of various effective interactions are also examined in relation to the effective mass.

Yoshida, Satoshi [Science Research Center, Hosei University, 2-17-1 Fujimi, Chiyoda, Tokyo 102-8160 (Japan); Sagawa, Hiroyuki [Center for Mathematical Sciences, University of Aizu Aizu-Wakamatsu, Fukushima 965-8580 (Japan)

2008-05-15

374

The Giant Magnetocaloric Effect  

NASA Astrophysics Data System (ADS)

Since the discovery of the magnetocaloric effect in pure iron by E.Warburg in 1881, it has been measured experimentally on many magnetic metals and compounds. The majority of the materials studied order magnetically undergoing a second order phase transformation. The magnetocaloric effect, typically peaking near the Curie or the Néel temperature, generally ranges from 0.5 to 2 K (in terms of adiabatic temperature change) or at 1 to 4 J/kg K (in terms of isothermal magnetic entropy change) per 1 T magnetic field change. The giant magnetocaloric effect recently discovered in Gd_5(Si_xGe_1-x)4 alloys, where x <= 0.5, is associated with a first order magnetic phase transition and it reaches values of 3 to 4 K and 6 to 10 J/kg K per 1 T field change, respectively. The refrigerant capacity, which is the measure of how much heat can be transferred from a cold to a hot reservoir in one ideal thermodynamic cycle, is larger than that of the best second order phase transition materials by 25 to 100%. When the Gd_5(Si_xGe_1-x)4 alloys are compared with other known materials, which show first order magnetic phase transition, such as Dy, Ho, Er, HoCo_2, NdMn_2Si_2, Fe_0.49Rh_0.51, and (Hf_0.83Ta_0.17)Fe_2+x, only Fe_0.49Rh_0.51 has comparable magnetocaloric properties. However, the first order magnetic phase transition in Fe_0.49Rh_0.51 is irreversible, and the magnetocaloric effect disappears after one magnetizing/demagnetizing cycle. A study of the crystal structure, thermodynamics, and magnetism of the Gd_5(Si_xGe_1-x)4 alloys, where 0 <= x <= 1 allowed us to obtain a qualitative understanding of the basic relations between the composition, the crystal structure, and the change in thermodynamics and magnetocaloric properties, which occur in the Gd_5(Si_xGe_1-x)4 system, and which brings about the giant magnetocaloric effect when x <= 0.5.

Pecharsky, Vitalij K.

1998-03-01

375

Health effects of nonionizing radiation  

SciTech Connect

Electromagnetic energy in the microwave and radiofrequency bands can produce biologic effects, which are predominantly thermal. During therapeutic use under medical supervision, desired biologic effects are produced and potentially injurious effects minimized. The biologic effects of electromagnetic fields have materialized because of a recent concern that relatively low-level fields produced by everyday electrical appliances, wiring in the home, and power transmission lines may be causally related to a number of detrimental health effects.41 references.

Wilkening, G.M.; Sutton, C.H. (AT T Bell Laboratories, Murray Hill, NJ (USA))

1990-03-01

376

Causal diagrams, the placebo effect, and the expectation effect.  

PubMed

Using causal diagrams, a formal research methodology, we analyzed several definitions of placebo and the placebo effect. We conclude that placebo is an ambiguous, redundant term and that the so-called placebo effect conceals far more interesting effects that are attributed to the patient's expectation. Biomedical research will benefit from abandoning the term placebo effect and focusing instead on a deeper understanding of the expectation variable, including its causes, effects, and effect modifiers. This avenue of research should be pursued by observational cohorts that are nested within clinical trials. PMID:24101881

Shahar, Eyal; Shahar, Doron J

2013-09-27

377

Causal diagrams, the placebo effect, and the expectation effect  

PubMed Central

Using causal diagrams, a formal research methodology, we analyzed several definitions of placebo and the placebo effect. We conclude that placebo is an ambiguous, redundant term and that the so-called placebo effect conceals far more interesting effects that are attributed to the patient’s expectation. Biomedical research will benefit from abandoning the term placebo effect and focusing instead on a deeper understanding of the expectation variable, including its causes, effects, and effect modifiers. This avenue of research should be pursued by observational cohorts that are nested within clinical trials.

Shahar, Eyal; Shahar, Doron J

2013-01-01

378

The flash grab effect.  

PubMed

When an object moves back and forth, its trajectory appears significantly shorter than it actually is. The object appears to stop and reverse well before its actual reversal point, as if there is some averaging of location within a window of about 100ms (Sinico et al., 2009). Surprisingly, if a bar is flashed at the physical end point of the trajectory, right on top of the object, just as it reverses direction, the flash is also shifted - grabbed by the object - and is seen at the perceived endpoint of the trajectory rather than the physical endpoint. This can shift the perceived location of the flash by as much as 2 or 3 times its physical size and by up to several degrees of visual angle. We first show that the position shift of the flash is generated by the trajectory shortening, as the same shift is seen with or without the flash. The flash itself is only grabbed if it is presented within a small spatiotemporal attraction zone around the physical end point of the trajectory. Any flash falling in that zone is pulled toward the perceived endpoint. The effect scales linearly with speed, up to a maximum, and is independent of the contrast of the moving stimulus once it is above 5%. Finally, we demonstrate that this position shift requires attention. These results reveal a new "flash grab" effect in the family of motion-induced position shifts. Although it most resembles the flash drag effect, it differs from this in the following ways: (1) it has a different temporal profile, (2) it requires attention, (3) it is about 10 times larger. PMID:23872166

Cavanagh, Patrick; Anstis, Stuart

2013-07-18

379

Adverse antiepileptic drug effects  

PubMed Central

Background: Adverse effects (AEs) of antiepileptic drugs (AEDs) are a major impediment to optimal dosing for seizure control. Better understanding of clinical properties of AEs is a prerequisite for systematic research of their neurobiological underpinnings. This study aimed to define specific patterns of AE occurrence and determine their clinical relevance based on their association with subjective health status. Methods: Two hundred subjects with epilepsy completed validated self-report health assessments, including the Adverse Event Profile (AEP) and Quality of Life in Epilepsy Inventory (QOLIE)-89. Factor analysis was performed on the 19 AEP items to identify distinct classes of AEs. Correlations between AE class scores and QOLIE-89 scores were evaluated. Multivariate analysis was used to assess contributions of AE class scores to QOLIE-89 scores after controlling for depression and seizure frequency. Relationships between changes in AE class scores and changes in QOLIE-89 scores were also investigated in a subgroup of 62 subjects enrolled in a randomized trial. Results: The mean number of AEs per subject was 6.5. AEs were segregated into five classes: Cognition/Coordination, Mood/Emotion, Sleep, Weight/Cephalgia, and Tegument/Mucosa. Higher scores in each AE class were associated with lower QOLIE-89 scores. Cognition/Coordination scores were the strongest predictor of QOLIE-89 scores. Improvements in Cognition/Coordination, Mood/Emotion, and Tegument/Mucosa scores were associated with improvements in QOLIE-89 scores. Improved Cognition/Coordination was the only predictor of improved QOLIE-89. Conclusion: Adverse effects (AEs) of antiepileptic drugs can be classified in five biologically plausible factors. When specific classes of AEs are identified and attempts are made to reduce them, quality of life is significantly improved. GLOSSARY AE = adverse effect; AED = antiepileptic drug; AEP = Adverse Event Profile; BDI = Beck Depression Inventory; GABA = ?-aminobutyric acid; HRQOL = Health-Related Quality of Life; QOLIE = Quality of Life in Epilepsy Inventory.

Perucca, Piero; Carter, Jewell; Vahle, Victoria; Gilliam, Frank G.

2009-01-01

380

'The Kesterson effect'  

USGS Publications Warehouse

Hypothesized to be derived from Cretaceous marine sedimentary rocks, selenium contamination of the Kesterson National Wildlife Refuge is traced through irrigation drainage to the source bedrock of the California Coast Ranges. This biogeochemical pathway of selenium is defined here as the 'Kesterson effect.' At the refuge ponds, this effect culminated in 1983 in a 64% rate of deformity and death of embryos and hatchlings of wild aquatic birds. From the previous companion paper on irrigation drainage, the Kesterson effect has been implicated in nine of 11 reconnaissance areas studied in the western United States. Deformities have resulted in at least five of these sites. Climatic, geologic, hydrologic, and soil conditions in these reconnaissance areas are similar to those in the area surrounding Kesterson National Wildlife Refuge in the west-central San Joaquin Valley of California, in California, selenium as selenate, was ultimately found weathered with sulfur from marine sources in soluble sodium and magnesium sulfate salts, which are concentrated by evaporation on farmland soils. The Se, mobilized by irrigation drainage, is bioaccumulated to toxic levels in refuge wetland ponds that are located mainly in hydrologically closed basins and thus act as concentrating disposal points. The depositional environment of the ponds may be similar to that of the nutrient-rich continental shelf edge and slope in which Cretaceous, Eocene, and Miocene sediments found to be seleniferous in the California Coast Ranges were deposited. Bioaccumulation may be therefore a primary mechanism of selenium enrichment in ancient sediments in addition to that of the formerly suggested Cretaceous volcanic pathway.

Presser, T. S.

1994-01-01

381

Immunosuppressive effects of defibrotide.  

PubMed

The effect of defibrotide (DF) alone or in combination with CsA was examined using in vitro proliferation assays with human PBLs and in vivo heterotopic heart allografts in rats. DF alone (12.5-50 mg/ml) inhibited in vitro PBL proliferation more effectively after PHA (50-56%) or OKT3 (50-95%), than after alloantigenic (25-30%), stimulation. Furthermore, the combination of DF (1-4 mg/ml) with CsA (10-40 ng/ml) caused an 85.2-86.8% reduction in proliferative responses after OKT3 stimulation. Median-effect analysis documented that the combination index for DF and CsA was consistently lower than 0.3 at various concentration ratios of the 2 agents. Combination index values below 1.0 reflect drug synergism; those equal to 1.0 show additive, and above 1.0, antagonistic, interactions. Daily intraperitoneal injections of DF (150 mg/kg) failed to prolong the survival of Buffalo (RT-1b) heart allografts in Wistar-Furth (RT-1u) recipients, namely mean survival times of 7.0 +/- 0.7 days with, vs. 6.5 +/- 0.5 days without, DF treatment. Similarly, intravenous or intra-arterial infusion of DF (280 mg/kg) delivered directly into the heart allograft by a 7-day osmotic pump was ineffective. However, a course of local, but not systemic, DF (280 mg/kg) combined with a 14-day i.v. administration of a subtherapeutic dose of CsA (1 mg/kg) significantly prolonged heart allograft survival to 22.8 +/- 5.0 days (P < 0.001). Thus, in vitro DF is immunosuppressive alone at high concentrations, and in combination with CsA at low concentrations. Continuous infusion of DF into the graft combined with systemic administration of CsA prolonged transplant survival in vivo. These findings suggest that high tissue levels of DF potentiate the immunosuppressive effects of CsA. PMID:8212219

Ferraresso, M; Rigotti, P; Stepkowski, S M; Chou, T C; Kahan, B D

1993-10-01

382

Greenhouse Effect Lab  

NSDL National Science Digital Library

In this simple lab, students collect data to demonstrate basic atmospheric science concepts. Groups of students measure the effect of carbon dioxide on temperature using soda bottles with thermometers inserted. One bottle is filled with air and capped. The second bottle is filled with carbon dioxide using a specific procedure. To conduct the experiment, both bottles are placed under a lamp while students record the increase in temperature over five minutes. The bottle containing carbon dioxide has a greater increase in temperature than the bottle containing air. This lab demonstrates the fundamental concept that underlies climate change science by providing data that are easy for students to interpret.

Larsen, Krista

383

Effect of Auxin  

Microsoft Academic Search

The effect of auxin on the physiology of protoplasts from growing oat (Avena sativa L.) coleoptiles was investigated. Protoplasts, iso- lated iso-osmotically from peeled oat coleoptile segments, were found to swell steadily over many hours. lncubated in 1 mM CaCI,, 1 O mM KCI, 1 O mM 2-(morpholino)ethanesulfonic acid\\/lJ-bis- Itris(hydroxymethyl)methylaminolpropane, pH 6.5, and mannitol to 300 milliosmolal, protoplasts swelled 28.9%

Christopher P. Keller; Elizabeth Van Volkenburgh

384

Is health education effective?  

PubMed

Primary health care (PHC) workers from 20 hospitals, PHC nurses, community health care nurses, and other PHC workers attended a session on health education and effectiveness in South Africa in September 1991. Discussion is directed to an overview of health education as presented in the day's session, the effectiveness of health education, and recommendations for improving health education. The first session on health education aimed to explore the breadth of possibilities for health education, and to emphasize some important problems, such as inconsistency in messages. Role plays were enacted within different groups: the 1991 Tintswalo PHC nurses class, the Tintswalo People's Awareness of Disability Issues group, and the Nkhensani PHC nurses group. The second session involved a panel discussion with 4 speakers. The first speaker directed attention to the need for an adequate education as insurance for effective health education. Modern trends have been responsible for the destruction of black culture. There is a problem of victim blaming, when in fact the problem of rural mortality is the system. Socioeconomic conditions and politics must be changed before health education can be effective. Health personnel as representatives of the middle class may be viewed as part of the problem. The second speaker spoke of the ineffectiveness of teaching someone what ought to be eaten but not providing the means to acquire the food. Oppression has led to blaming the oppressed. The third speaker noted that health workers were indeed part of the problem, e.g., health workers do not practice the advice given out and many times are junior personnel who are not evaluated. There are requirements for tracking what nurses do, but little on evaluation of appropriate messages. Appearance replaces substance. The fourth speaker felt health education is about training people and satisfying the educator and the system. Politics and health were related and too much time was misdirected to fighting with the community. Situation analysis was recommended before action was taken. Recommendations involved, for instance, building rapport with the community, and the need for a greater grasp of health knowledge by health educators. PMID:1356228

McKenzie, A; Ngobeni, O; Bonongo, F

1992-07-01

385

On nature's scaling effects  

NASA Astrophysics Data System (ADS)

This presentation afforded the opportunity to look back in the literature to discover scaling effects in nature that might be relevant to composites. Numerous examples were found in nature's approaches to wood, teeth, horns, leaves, eggs, feathers, etc. Nature transmits tensile forces rigidly with cohesive bonds, while dealing with compression forces usually through noncompressible hydraulics. The optimum design scaling approaches for aircraft were also reviewed for comparison with similitude laws. Finally, some historical evidence for the use of Weibull scaling in composites was reviewed.

Wilkins, Dick J.

1994-07-01

386

Hepatoprotective effects of mushrooms.  

PubMed

The particular characteristics of growth and development of mushrooms in nature result in the accumulation of a variety of secondary metabolites such as phenolic compounds, terpenes and steroids and essential cell wall components such as polysaccharides, b-glucans and proteins, several of them with biological activities. The present article outlines and discusses the available information about the protective effects of mushroom extracts against liver damage induced by exogenous compounds. Among mushrooms, Ganoderma lucidum is indubitably the most widely studied species. In this review, however, emphasis was given to studies using other mushrooms, especially those presenting efforts of attributing hepatoprotective activities to specific chemical components usually present in the mushroom extracts. PMID:23884116

Soares, Andréia Assunço; de Sá-Nakanishi, Anacharis Babeto; Bracht, Adelar; da Costa, Sandra Maria Gomes; Koehnlein, Eloá Angélica; de Souza, Cristina Giatti Marques; Peralta, Rosane Marina

2013-07-01

387

Interface effects on nanoelectronics  

NASA Astrophysics Data System (ADS)

Nanoelectronics consist of devices with active electronic components on the nanometer length scale. At such dimensions most, if not all, atoms or molecules composing the active device region must be on or near a surface. Also, materials effectively confined to two dimensions, or when subject to abrupt boundary conditions, generally do not behave the same as materials inside three dimensional, continuous structures. This dissertation is a quantitative determination of how surfaces and interfaces in organic nanoelectronic devices affect properties such as charge transport, electronic structure, and material fluctuations. Si/SiO2 is a model gate/gate dielectric for organic thin film transistors, therefore proper characterization and measurement of the effects of the SiO2/organic interface on device structures is extremely important. I fabricated pentacene thin film transistors on Si/SiO2 and varied the conduction channel thickness from effectively bulk (˜40nm) to 2 continuous conducting layers to examine the effect of substrate on noise generation. The electronic spectral noise was measured and the generator of the noise was determined to be due to the random spatial dependence of grain boundaries, independent of proximity to the gate oxide. This result led me to investigate the mechanisms of pentacene grain formation, including the role of small quantities of impurities, on silicon dioxide substrates. Through a series of nucleation, growth and morphology studies, I determined that impurities assist in nucleation on SiO2, decreasing the stable nucleus size by a third and increasing the overall number of grains. The pentacene growth and morphology studies prompted further exploration of pentacene crystal growth on SiO2. I developed a method of making atomically clean ultra-thin oxide films, with surface chemistry and growth properties similar to the standard thick oxides. These ultra-thin oxides were measured to be as smooth as cleaned silicon and then used as substrates for scanning tunneling microscopy of pentacene films. The increased spatial resolution of this technique allowed for the first molecular resolution characterization of the standing-up pentacene crystal structure near the gate dielectric, with molecules oriented perpendicular to the SiO2 surface. Further studies probed how growth of C60 films on SiO2 and pentacene surfaces affected C60 morphology and electronic structure to better understand solar cell heterojunctions.

Conrad, Brad Richard

388

Interfacial effects in multilayers  

SciTech Connect

Interfacial structure and the atomic interactions between atoms at interfaces in multilayers or nano-laminates have significant impact on the physical properties of these materials. A technique for the experimental evaluation of interfacial structure and interfacial structure effects is presented and compared to experiment. In this paper the impact of interfacial structure on the performance of x-ray, soft x-ray and extreme ultra-violet multilayer optic structures is emphasized. The paper is concluded with summary of these results and an assessment of their implications relative to multilayer development and the study of buried interfaces in solids in general.

Barbee, T.W., Jr.

1998-04-01

389

Effects of Time on the Effectiveness of Dispersants. Final Version.  

National Technical Information Service (NTIS)

The objective of this study was to determine whether dispersants will remain with treated oil slicks over time and retain effectiveness. If dispersants remain effective for significant periods ot time, oil spill responders can consider dispersants in scen...

I. Eide J. Guyomarch J. L. Resby P. J. Brandvik P. S. Daling

2007-01-01

390

Acrolein health effects.  

PubMed

Acrolein is a chemical used as an intermediate reactive aldehyde in chemical industry. It is used for synthesis of many organic substances, methionine production, and methyl chloride refrigerant. The general population is exposed to acrolein via smoking, second-hand smoke, exposure to wood and plastic smoke. Firefighters and population living or working in areas with heavy automotive traffic may expose to higher level of acrolein via inhalation of smoke or automotive exhaust. Degradation of acrolein in all environmental media occurs rapidly, therefore, environmental accumulation is not expected. Acrolein degrade in 6A days when applied to surface water, and it has not been found as a contaminant in municipal drinking water. Acrolein vapor may cause eye, nasal and respiratory tract irritations in low level exposure. A decrease in breathing rate was reported by volunteers acutely exposed to 0.3A ppm of acrolein. At similar level, mild nasal epithelial dysplasia, necrosis, and focal basal cell metaplasia have been observed in rats. The acrolein effects on gastrointestinal mucosa in the animals include epithelial hyperplasia, ulceration, and hemorrhage. The severity of the effects is dose dependent. Acrolein induces the respiratory, ocular, and gastrointestinal irritations by inducing the release of peptides in nerve terminals innervating these systems. Levels of acrolein between 22 and 249 ppm for 10 min induced a dose-related decrease in substance P (a short-chain polypeptide that functions as a neurotransmitter or neuromodulator). PMID:19028774

Faroon, O; Roney, N; Taylor, J; Ashizawa, A; Lumpkin, M H; Plewak, D J

2008-08-01

391

Predicting Earthquake Effects  

NASA Astrophysics Data System (ADS)

Advances in the earth sciences and information technology have lead to dramatic improvements in our ability to respond to, as well as anticipate and mitigate, earthquake effects in our communities. The development of Geographic Information System (GIS) based tools such as ShakeMap and HAZUS have ushered in a new era of risk and emergency management. Real-time maps of strong ground motion, coupled with engineering-based descriptions of building and infrastructure inventory and vulnerability enable more accurate determinations of the location and severity of earthquake damage and the socio-economic consequences for emergency managers and officials following significant earthquakes. The ability to map the distribution and growth of seismic risk in the United States has long-term benefits for public policy as well. Long-term forecasts of seismic risk based on varying mitigation strategies can provide guidance for developing national and local earthquake policy. The successful performance of the Trans-Alaska pipeline during the 2002 Denali earthquake illustrates the dependence of performance-based engineering on the ability to predict earthquake effects (e.g., levels of strong ground motion, amounts of fault displacement or ground deformation). Being able to reduce the uncertainty in predicting these parameters has significant economic consequences and enables decision makers to more efficiently prioritize risk management strategies.

Nishenko, S.

2005-12-01

392

Ecotoxicological effects extrapolation models  

SciTech Connect

One of the central problems of ecological risk assessment is modeling the relationship between test endpoints (numerical summaries of the results of toxicity tests) and assessment endpoints (formal expressions of the properties of the environment that are to be protected). For example, one may wish to estimate the reduction in species richness of fishes in a stream reach exposed to an effluent and have only a fathead minnow 96 hr LC50 as an effects metric. The problem is to extrapolate from what is known (the fathead minnow LC50) to what matters to the decision maker, the loss of fish species. Models used for this purpose may be termed Effects Extrapolation Models (EEMs) or Activity-Activity Relationships (AARs), by analogy to Structure-Activity Relationships (SARs). These models have been previously reviewed in Ch. 7 and 9 of and by an OECD workshop. This paper updates those reviews and attempts to further clarify the issues involved in the development and use of EEMs. Although there is some overlap, this paper does not repeat those reviews and the reader is referred to the previous reviews for a more complete historical perspective, and for treatment of additional extrapolation issues.

Suter, G.W. II

1996-09-01

393

Effect Sizes, Confidence Intervals, and Confidence Intervals for Effect Sizes  

ERIC Educational Resources Information Center

The present article provides a primer on (a) effect sizes, (b) confidence intervals, and (c) confidence intervals for effect sizes. Additionally, various admonitions for reformed statistical practice are presented. For example, a very important implication of the realization that there are dozens of effect size statistics is that "authors must…

Thompson, Bruce

2007-01-01

394

Research on HEMP injection and radiation effect effect of EED  

Microsoft Academic Search

High-altitude nuclear electromagnetic pulse (HEMP) will lead to EED misoperation (such as early burst) or degradation of the performance and reliability (such as failure) etc. This paper is mainly about injection effect test and radiation effect test of high-altitude EMP on EED, tests are performed in typical HEMP environments. On this basis, researched and analyzed HEMP effect on EED. Analysis

Xiangfei Ji; Qingmei Feng; Tuan Zhao; Hongzhi Yao

2009-01-01

395

Longitudinal Spin Seebeck Effect  

NASA Astrophysics Data System (ADS)

The spin Seebeck effect (SSE) refers to the generation of a spin voltage as a result of a temperature gradient in magnetic materials [1-7]. Here, a spin voltage is a potential for electron spins to drive a nonequilibrium spin current; when a conductor is attached to a magnet with a finite spin voltage, it induces a spin injection into the conductor. The SSE is of crucial importance in spintronics and spin caloritronics, since it enables simple and versatile generation of a spin current from heat. The simplest and most straightforward setup of the SSE is the longitudinal configuration [4], in which a spin current flowing parallel to a temperature gradient is measured via the inverse spin Hall effect (ISHE). The longitudinal SSE device consists of a ferromagnetic or ferrimagnetic insulator (FI, e.g. YIG) covered with a paramagnetic metal (PM, e.g. Pt) film. When a temperature gradient is applied perpendicular to the FI/PM interface, an ISHE-induced voltage is generated in the PM layer. In this talk, we report the observation of the longitudinal SSE in various FI/PM systems and provide evidence that the longitudinal SSE is free from thermoelectric artefact [7], i.e., the anomalous Nernst effect caused by extrinsic magnetic proximity [8]. Then, we discuss the longitudinal SSE from an application point of view [6]. We thank E. Saitoh, S. Maekawa, G. E. W. Bauer, X.-F. Jin, H. Adachi, D. Hou, D. Tian, T. Kikkawa, A. Kirihara, and M. Ishida for their support and valuable discussions. [4pt] [1] K. Uchida et al., Nature 455, 778 (2008).[0pt] [2] K. Uchida et al., Nature Mater. 9, 894 (2010).[0pt] [3] C. M. Jaworski et al., Nature Mater. 9, 898 (2010).[0pt] [4] K. Uchida et al., Appl. Phys. Lett. 97, 172505 (2010).[0pt] [5] K. Uchida et al., Nature Mater. 10, 737 (2011).[0pt] [6] A. Kirihara et al., Nature Mater. 11, 686 (2012).[0pt] [7] T. Kikkawa et al., arXiv:1211.0139 (2012). [0pt] [8] S. Y. Huang et al., Phys. Rev. Lett. 109, 107204 (2012).

Uchida, Ken-Ichi

2013-03-01

396

Health Effects of Dietary Carnitine.  

National Technical Information Service (NTIS)

The report reviews the health effects of carnitine with emphasis on dietary sources, possible essentiality, differential effects of optical isomers, and consequences of oral administration for nutritional and therapeutic purposes. Metabolic needs for carn...

P. R. Borum K. D. Fisher

1983-01-01

397

Disney Effects Using Implicit Surfaces  

Microsoft Academic Search

this paper we briefly summarise the ABC of implicit surfaces, present and justify the model usedin our system and describe how Disney effects are automatically created. Each effect will be discussed separatelypointing out the advantages and drawbacks of our techniques.

Agata Opalach; Steve Maddock

1994-01-01

398

Piezoelectricity: Venerable Effect, Modern Thrusts.  

National Technical Information Service (NTIS)

A synopsis of the piezoelectric effect is presented in the context of its history, traditional uses, and relation to crystal symmetry. Associated effects are briefly noted. Future prospects, particularly in the area of microelectromechanical systems/struc...

A. Ballato

1994-01-01

399

Managing Chemotherapy Side Effects: Pain  

MedlinePLUS

... anD human services national institutes of health Managing Chemotherapy Side Effects Pain Call the doctor or nurse ... and am able to enjoy life more!” Managing Chemotherapy Side Effects: Pain Keep track of the pain. ...

400

Effects of the Prostaglandin PGBx.  

National Technical Information Service (NTIS)

The experimental studies were initiated as a result of the discovery of a prostaglandin derivative, PGBx, with unique enhancing effects on mitochondrial enzymatic systems, especially those involved in oxidative phenomena. It was thought that such effects ...

L. Goldstein

1973-01-01

401

IMPROVED LABORATORY DISPERSANT EFFECTIVENESS TEST  

EPA Science Inventory

The U.S. Environmental Protection Agency (EPA) initiated a program to evaluate an Improved Laboratory Dispersant Effectiveness Test (ILDET) which was developed to replace EPA's Revised Standard Dispersant Effectiveness Test (RSDET). The report summarizes the development of the IL...

402

Alcohol's Effects on the Body  

MedlinePLUS

... Drinking Statistics What Is A Standard Drink? Moderate & Binge Drinking Alcohol's Effects on the Body Alcohol Use Disorders ... Other Psychiatric Disorders Other Substance Abuse HIV/AIDS Alcohol's Effects on the Body Drinking too much – on ...

403

Side Effects: Questions and Answers  

Center for Drug Evaluation (CDER)

... Another way to learn about your drug's side effects or safety concerns is to use the Index to Drug ... How do I report a suspected drug side effect? ... More results from www.fda.gov/drugs/resourcesforyou/consumers

404

The Greenhouse Effect  

NSDL National Science Digital Library

This site is a joint effort of NOAA Research and the College of Education at the University of South Alabama. The goal of the site is to provide middle school science students and teachers with research and investigation experiences using on-line resources. In this unit students learn about what the greenhouse effect is and what causes it. By looking at greenhouse gas rates and amounts, students can propose reasons for trends and solutions to global warming. Parts of the unit include gathering information from other websites, applying the data gathered, and performing enrichment exercises. This site contains a downloadable teachers guide, student guide, and all activity sheets to make the unit complete.

405

Biological effects of ozone  

SciTech Connect

Tropospheric ozone, a classic anthropogenic air pollutant, is going to remain a troublesome byproduct of contemporary civilization for many decades. We have known for some time that the hydrocarbons and nitrogen oxides from motor vehicles, together with actinic radiation, account for local and regional photochemistry leading to prolonged afternoon ozone peaks. We also now know that agricultural burning and intensive animal husbandry elevate regional and mesoscale concentrations of ozone and its precursors, and that remote background levels of ozone have been rising steadily throughout this century. The changes we will have to make in emission controls to appreciably reduce current tropospheric ozone levels will have profound effects on our transportation systems, consumer products, and lifestyles. As a society, we will have to make difficult choices about the levels of ozone-associated health, welfare, and natural system damage we will tolerate, or conversely, how much we are willing to pay for controls which can minimize the damage.

Lippmann, M. (New York Univ. Medical Center, Tuxedo, NY (USA))

1989-09-01

406

Parent of origin effects.  

PubMed

A major weakness of most genome-wide association studies has been their inability to fully explain the heritable component of complex disease. Nearly all such studies consider the two parental alleles to be functionally equivalent. However, the existence of imprinted genes demonstrates that this assumption can be wrong. In this review, we describe a wide variety of different mechanisms that underlie many other parent of origin and trans-generational effects that are known to operate in both humans and model organisms, suggesting that these phenomena are perhaps not uncommon in the genome. We propose that the consideration of alternative models of inheritance will improve our understanding of the heritability and causes of human traits and could have significant impacts on the study of complex disorders. PMID:21933173

Guilmatre, A; Sharp, A J

2011-10-30

407

The hot chocolate effect  

NASA Astrophysics Data System (ADS)

The ''hot chocolate effect'' was investigated quantitatively, using water. If a tall glass cylinder is filled nearly completely with water and tapped on the bottom with a softened mallet one can detect the lowest longitudinal mode of the water column, for which the height of the water column is one-quarter wavelength. If the cylinder is rapidly filled with hot tap water containing dissolved air the pitch of that mode may descend by nearly three octaves during the first few seconds as the air comes out of solution and forms bubbles. Then the pitch gradually rises as the bubbles float to the top. A simple theoretical expression for the pitch ratio is derived and compared with experiment. The agreement is good to within the 10% accuracy of the experiments.

Crawford, Frank S.

1982-05-01

408

[Side effects of caffeine].  

PubMed

Caffeine is one of the most commonly ingested alkaloids worldwide. It is present in coffee, tea, soft and energy drinks, chocolate, etc. Currently published data has been stressed that the metyloxantine consumption increases the risk of coronary heart disease, arterial hypertension, arterial stiffness, and an elevation of cholesterol and homocysteine plasma concentration. The acute high consumption may also modulate insulin sensitivity and glucose blood level. However, the long-term consumption reduces the incidence of the type 2 diabetes mellitus. When administered in high doses the substance may cause various side effects, related to abnormal stimulation of the central nervous system, decrease tonus of the lower esophageal sphincter, as well as increase risk of miscarriage and intrauterine growth retardation. The final manifestation of side reactions is dependent on the genotype, especially polymorphisms of genes associated with caffeine metabolism, i.e., cytochrome P450-CYP1A2 and catechol-O-methyltransferase (COMT). PMID:19999796

Dworza?ski, Wojciech; Opielak, Grzegorz; Burdan, Franciszek

2009-11-01

409

Remarks on Effect Algebras  

NASA Astrophysics Data System (ADS)

Erik M. Alfsen and Frederic W. Shultz had recently developed the characterisation of state spaces of operator algebras. It established full equivalence (in the mathematical sense) between the Heisenberg and the Schrödinger picture, i.e. given a physical system we are able to construct its state space out of its observables as well as to construct algebra of observables from its state space. As an underlying mathematical structure they used the theory of duality of ordered linear spaces and obtained results are valid for various types of operator algebras (namely C *, von Neumann, JB and JBW algebras). Here, we show that the language they developed also admits a representation of an effect algebra.

Majewski, W?adys?aw A.; Tylec, Tomasz I.

2010-12-01

410

The Energy Diameter Effect  

SciTech Connect

Various relations for the detonation energy and velocity as they relate to the inverse radius of the cylinder are explored. The detonation rate-inverse slope relation seen in reactive flow models can be used to derive the familiar Eyring equation. Generalized inverse radii can be shown to fit large quantities of cylinder and sphere results. A rough relation between detonation energy and detonation velocity is found from collected JWL values. Cylinder test data for ammonium nitrate mixes down to 6.35 mm radii are presented, and a size energy effect is shown to exist in the Cylinder test data. The relation that detonation energy is roughly proportional to the square of the detonation velocity is shown by data and calculation.

Souers, P; Vitello, P; Garza, R; Hernandez, A

2007-04-20

411

The Energy Diameter Effect  

SciTech Connect

We explore various relations for the detonation energy and velocity as they relate to the inverse radius of the cylinder. The detonation rate-inverse slope relation seen in reactive flow models can be used to derive the familiar Eyring equation. Generalized inverse radii can be shown to fit large quantities of cylinder results. A rough relation between detonation energy and detonation velocity is found from collected JWL values. Cylinder test data for ammonium nitrate mixes down to 6.35 mm radii are presented, and a size energy effect is shown to exist in the Cylinder test data. The relation that detonation energy is roughly proportional to the square of the detonation velocity is shown by data and calculation.

Vitello, P; Garza, R; Hernandez, A; Souers, P C

2007-07-10

412

Neutralization and system effectiveness  

SciTech Connect

Security forces that can neutralize an attack force are essential to effectively safeguard special nuclear material (SNM) against theft or sabotage. Probability of neutralization, P(N), estimates the likelihood that security forces will win given that security forces interrupt the attackers and begin an armed engagement. Brief Adversary Threat Loss Estimator (BATLE) calculates P(N). BATLE was developed for the Nuclear Regulatory Commission in 1980. This paper describes a total repackaging of BATLE which will be called the Threat Neutralization Model. New features and capabilities are (1) guidance to the user in setting up the input parameters, (2) faster software, (3) graphical output and sensitivity curves to assist the user in interpreting the results, (4) compatibility with the SAVI vulnerability analysis program, and (5) operation under Microsoft Windows on personal computers.

Paulus, W.K.

1988-01-01

413

THE HOT CHOCOLATE EFFECT  

SciTech Connect

The "hot chocolate effect" was investigated quantitatively, using water. If a tall glass cylinder is filled nearly completely with water and tapped on the bottom with a softened mallet one can detect the lowest longitudinal mode of the water column, for which the height of the water column is one quarter wavelength. If the cylinder is rapidly filled with hot tap water containing dissolved air the pitch of that mode may descend by nearly three octaves during the first few seconds as the air comes out of solution and forms bubbles. Then the pitch gradually rises as the bubbles float to the top. A simple theoretical expression for the pitch ratio is derived and compared with experiment. The agreement is good to within the ten percent accuracy of the experiments.

Crawford, Frank S.

1980-12-01

414

Hot chocolate effect  

SciTech Connect

The ''hot chocolate effect'' was investigated quantitatively, using water. If a tall glass cylinder is filled nearly completely with water and tapped on the bottom with a softened mallet one can detect the lowest longitudinal mode of the water column, for which the height of the water column is one-quarter wavelength. If the cylinder is rapidly filled with hot tap water containing dissolved air the pitch of that mode may descend by nearly three octaves during the first few seconds as the air comes out of solution and forms bubbles. Then the pitch gradually rises as the bubbles float to the top. A simple theoretical expression for the pitch ratio is derived and compared with experiment. The agreement is good to within the 10% accuracy of the experiments.

Crawford, F.S.

1982-05-01

415

Topological Magnetoelectric Effect Decay  

NASA Astrophysics Data System (ADS)

We address the influence of realistic disorder and finite doping on the effective magnetic monopole induced near the surface of an ideal topological insulator (TI) by currents that flow in response to a suddenly introduced external electric charge. We show that when the longitudinal conductivity ?xx=g(e2/h)?0, the apparent position of a magnetic monopole initially retreats from the TI surface at speed vM=?cg, where ? is the fine structure constant and c is the speed of light. For the particular case of TI surface states described by a massive Dirac model, we further find that the temperature T=0 Hall currents vanish when the external potential is screened.

Pesin, D. A.; MacDonald, A. H.

2013-07-01

416

Unparticle phase effects  

NASA Astrophysics Data System (ADS)

Unparticles proposed by Georgi carry CP conserving phases in their propagators. We demonstrate that these peculiar phases have an important impact on CP violation. Without including the strong QCD phases, we study the unparticle phase effects on the direct CP asymmetries in the exclusive decays of B¯d??+?- and B??K, in which the flavor changing neutral currents are forbidden at tree level but induced by one-loop diagrams. Interesting and consistent results comparing to the data are obtained. In addition, we find that unparticles will significantly enhance the differential branching ratio of b?s?+?- at the small invariant mass of ?+?-. The forward-backward asymmetries for b?s?+?- due to unparticles are also explored.

Chen, Chuan-Hung; Geng, Chao-Qiang

2007-08-01

417

Environmental effects of mining  

SciTech Connect

The mining and mineral process industry has had very strong demands placed on it in recent decades, as the extent of its effects on the environment has become better understood and public concern has increased. Important progress has been made in both awareness and comprehension of the problems created by mineral production and in knowledge of how to prevent, mitigate and correct them. The first half of the book covers exploration and development, extraction processes, metallurgical processing and refining, decommissioning, environmental and ecological analysis, transportation analysis, residual dispersion, protection, rehabilitation, reclamation, regulation, standards and monitoring. The second half consists of chapters devoted to specific mined commodities. Each chapter covers a commodity, its production history, the situation of orebodies, ore extraction, ore processing, specific impacts on the environment, and short- and long-term remediation methods. Case histories are used to provide detail.

Crowder, A.A. [Queen`s Univ., Kingston, Ontario (Canada); Ripley, E.A.; Redmann, R.E. [Univ. of Saskatchewan, Saskatoon, Saskatchewan (Canada)

1995-12-01

418

Adverse effects of bisphosphonates.  

PubMed

Use of bisphosphonates has been growing steadily in the last decade. This follows the introduction of simpler dosing regimes, the availability of lower-priced generics, and concerns about the safety of hormone-replacement therapy. Bisphosphonates have a relatively good safety record and are tolerated by the majority of patients, but serious adverse events have been recorded in some cases. Only the most common of adverse effects are robustly observable in clinical trials. In general, studies were not powered to detect effects that were lower in incidence than fractures. This review of adverse events in bisphosphonate-treated patients was based on published information from case reports, case series, claims databases, national databases, surveys, adverse event reporting databases, and single or pooled clinical trials. The most common acute adverse events with bisphosphonates for osteoporosis are gastrointestinal discomfort and acute influenza-like illness. Renal complications are very rare with oral bisphosphonates and rare with i.v. bisphosphonates when used appropriately. Based on our current knowledge, skeletal events in the form of osteonecrosis of the jaw and atypical fragility fractures are rare compared with the risk of osteoporotic fractures, at least in patients with the same risk of fractures as those in the phase III trials. It is biologically plausible that atypical fragility fractures could follow from suppression of bone remodeling, but high-quality studies proving causality are lacking. Physicians are advised to critically reassess BMD and risk profile after 3-5 years of therapy to avoid treatment in patients at low risk. PMID:20407762

Abrahamsen, Bo

2010-04-21

419

Radiolytic effects of plutonium.  

SciTech Connect

Plutonium isotopes, most of them a-emitters, cause radiolytic changes in the matrix, in whic h they are embedded. The internal irradiation of Pu metal or its alloys results in physical changes, largel y as a result of the formation of helium bubbles, well-known to material scientists and weapons specialists . In all other media where plutonium occurs, usually as Pu'+ in an ionic form, the results of irradiation ar e chemical in nature. Homogenous media containing Pu, are often aqueous or non-aqueous solutions o f plutonium compounds, mostly originating during processing of spent nuclear fuel or from Pu processing . Heterogenous matrices containing plutonium are more complex from the point of view of radiolysis; they usually contain a variety of combinations of common materials contaminated with radionuclides . This class of radioactive materials represents a challenge for the management of plutonium waste . One has to consider a range of time scales for radiolytic effects (and consequently a several orders o f magnitude range of the cumulative dose) beginning with waste generation, through packaging, transportation, to the period of final storage . Final storage could be for thousands of years in deep geologic repositories . At every ' stage of that time scale, radiolysis proceeds continuously an d cumulative effects c an complicate operating procedures and final disposition . The results presented here have been obtained from experiments that have irradiated of model materials, which are typically the objects of contamination with plutonium . They were irradiated with linearly accelerated electrons up to very high dose rates, adjusted to simulate any contamination at any point on the time scale .

Zagorski, Z. (Zbigniew); Dziewinski, J. J. (Jacek J.); Conca, James L.

2003-01-01

420

Dispersant effectiveness: Studies into the causes of effectiveness variations  

SciTech Connect

Effectiveness, a key issue of using dispersants, is affected by many interrelated factors. The principal factors involved are the oil composition, dispersant formulation, sea surface turbulence and dispersant quantity. Oil composition is a very strong determinant. Current dispersant formulation effectiveness correlates strongly with the amount of saturate component in the oil. The other components of the oil, the asphaltenes, resins or polars and aromatic fractions show a negative correlation with the dispersant effectiveness. Viscosity is also a predictor of dispersant effectiveness and may have an effect because it is in turn determined by oil composition. Dispersant composition is significant and interacts with oil composition. Dispersants show high effectiveness at HLB values near 10. Sea turbulence strongly affects dispersant effectiveness.Effectiveness rises with increasing turbulence to a maximum value. Effectiveness for current commercial dispersants is gaussian around a peak salinity value. Peak effectiveness is achieved at very high dispersant quantities--at a ratio of 1:5, dispersant-to-oil volume. Dispersant effectiveness for those oils tested and under the conditions measured, is approximately logarithmic with dispersant quantity and will reach about 50% of its peak value at a dispersant to oil ratio of about 1:20 and near zero at a ratio of about 1:50.

Fingas, M.F.; Kyle, D. [Environment Canada, Ottawa, Ontario (Canada); Tennyson, E. [Minerals Management Service, Herndon, VA (United States)

1995-06-01

421

Fatigue Effects in Germanium Photodetectors  

NASA Astrophysics Data System (ADS)

Fatigue effects in germanium photodetectors were observed and studies carried out to determine the main components of these effects. Irradiance level, spectral distribution of the incident radiation and irradiated surface on the detector all play an important part in the existence and magnitude of fatigue effects. The time needed to recover the initial characteristics was also studied.

Lecollinet, P.; Bastie, J.

1993-01-01

422

KATABATIC FLOW WITH CORIOLIS EFFECT  

Microsoft Academic Search

Katabatic flows on long glaciers in high latitudes experience the Coriolis effect deflecting the flow thus affecting turbulent transports in the boundary layer. Analytically katabatic flows have been best represented by Prandtl model. However, the classic Prandtl model does not take into account the effect of the Coriolis force. It is found that after a straightforward inclusion of this effect,

Ivana Stiperski; Iva Kav; Branko Grisogono

423

Radiation effect on implanted pacemakers  

SciTech Connect

It was previously thought that diagnostic or therapeutic ionizing radiation did not have an adverse effect on the function of cardiac pacemakers. Recently, however, some authors have reported damaging effect of therapeutic radiation on cardiac pulse generators. An analysis of a recently-extracted pacemaker documented the effect of radiation on the pacemaker pulse generator.

Pourhamidi, A.H.

1983-10-01

424

Nonlinear effects in particulate processes  

Microsoft Academic Search

The nonlinear effects in various particulate processes are analyzed within the context of population balance modeling. Our main objective is to indicate the origin of the nonlinear effects and to categorize them in a systematic manner. To illustrate the importance of the nonlinear effects, a continuous milling process is considered, which has been analyzed in the literature with linear population

E. Bilgili; B. Scarlett

2005-01-01

425

Emotional intelligence and effective leadership  

Microsoft Academic Search

Emotional intelligence has become increasingly popular as a measure for identifying potentially effective leaders, and as a tool for developing effective leadership skills. Despite this popularity, however, there is little empirical research that substantiates the efficacy of emotional intelligence in these areas. The aim of the present paper was to explore the relationship between emotional intelligence and effective leadership. Emotional

Benjamin Palmer; Melissa Walls; Zena Burgess; Con Stough

2001-01-01

426

Ion Effects in 'Anaerobic Digestion'.  

National Technical Information Service (NTIS)

The report presents results of research on the effects of organic and inorganic ions on the anaerobic waste treatment process. Studied were the effects of various cations, the toxicity of various heavy metals, and the effect of high concentrations of indi...

P. L. McCarty I. J. Kugelman A. W. Lawrence

1964-01-01

427

Antimicrobial effect of zinc pyrithione  

Microsoft Academic Search

Synopsis The antimicrobial effect of zinc pyrithione has been studied with healthy scalps in relation to its ANTIDANDRUFF effect. Use of zinc pyrithione-containing shampoo sharply reduced the CORNEOCYTE COUNTS, while the similarly active antimicrobial agent, Irgasan DP-300 © had no effect on the corneocyte counts. Quantitative estimation of scalp microorganisms revealed that corresponding to the decrease in dandruff, Pityrospbrum ovale

GENJI IMOKAWA; HARUO SHIMIZU

428

Hall effect in spinor condensates  

SciTech Connect

We consider a neutral spinor condensate moving in a periodic magnetic field. The spatially dependent magnetic field induces an effective spin-dependent Lorentz force, which in turn gives rise to a spin-dependent Hall effect. Simulations of the Gross-Pitaevskii equation quantify the Hall effect. We discuss possible experimental realizations.

Taillefumier, Mathieu; Dahl, Eskil K.; Brataas, Arne [Department of Physics, Norwegian University of Science and Technology, N-7491 Trondheim (Norway); Hofstetter, Walter [Institut fuer Theoretische Physik, J. W. Goethe-Universitaet, Max-von-Laue-Strasse 1, 60438 Frankfurt/Main (Germany)

2009-07-01

429

Effective Programs for Latino Students.  

ERIC Educational Resources Information Center

|This collection of papers presents the current state of research on effective instructional programs for Hispanic American students. The 10 chapters are: (1) "Effective Programs for Latino Students in Elementary and Middle Schools" (Olatokunbo S. Fashola, Robert E. Slavin, Margarita Calderon, and Richard Duran); (2) "Effective Dropout Prevention…

Slavin, Robert E., Ed.; Calderon, Margarita, Ed.

430

The Effective Illumination of Streets  

Microsoft Academic Search

This paper mentions the dependence of effectiveness in street lighting upon municipal appropriations and efficient lamps, but discusses more particularly those aspects of effectiveness which are dependent upon skilful utilization of the light to produce the most effective illumination. There are included a classification of streets, a statement of the objects of street lighting and the elements of vision under

Preston S. Mllar

1915-01-01

431

Effective field theories from QCD.  

National Technical Information Service (NTIS)

We present a method for extracting effective Lagrangians from QCD. The resulting effective Lagrangians are based on exact rewrites of cut-off QCD in terms of these new collective field degrees of freedom. These cut-off Lagrangians are thus 'effective' in ...

R. Sollacher

1994-01-01

432

Assessing and Improving Institutional Effectiveness.  

ERIC Educational Resources Information Center

|Information to promote assessment of organizational effectiveness in colleges and universities is presented, along with an exercise to rank the effectiveness of 10 institutions. The exercise uses three types of criteria to indicate effectiveness: subjective ratings, data about students and activities, and institutional capacity and financial…

Cameron, Kim S.

433

Piezomagnetoelectric effects in anisotropic media  

Microsoft Academic Search

The effect of stress on the magnetoelectric polarisability is represented by a fourth-rank axial magnetic tensor called the piezomagnetoelectric effect. The non-zero independent components of the piezomagnetoelectric effect have been determined for each of the 90 magnetic crystal classes using a computer.

E. K. Stefanakos; R. F. Tinder; H. V. Thapliyal

1979-01-01

434

Effective Operators in Atomic Physics  

Microsoft Academic Search

The correlation effects of inter-electronic interactions between atomic configurations can be reproduced by effective orthogonal operators acting within a single configuration of interest. These operators which act on N electrons at a time can be resolved through the use of continuous Lie groups. This thesis details the development of these effective operators for a number of configurations. Complete sets of

Richard Carlson Leavitt

1989-01-01

435

Probiotics: mechanisms and established effects  

Microsoft Academic Search

The definition for probiotics has gradually changed with increasing understanding of the mechanisms by which they influence human health. Health effects related to changes in the intestinal microflora also accompany or are related to adhesion and immune system effects, competitive exclusion or metabolic and nutritional effects, with an increasing array of other potential modes of action. Most clinically documented and

Arthur C. Ouwehand; Pirkka V. Kirjavainen; Colette Shortt; Seppo Salminen

1999-01-01

436

Side effects with amiodarone therapy  

Microsoft Academic Search

Amiodarone hydrochloride is increasingly being used in the treatment of ventricular and supraventricular arrhythmias. Although a highly effective anti-arrhythmic agent, its use is restricted by the high incidence of side effects. To elucidate the value of monitoring serum level of both the parent drug and its active metabolite in predicting the occurrence of side effects, the investigators examined 109 patients

R. Shukla; N. I. Jowett; D. R. Thompson; J. E. Pohl

1994-01-01

437

Convolution effects in superconductive tunneling.  

PubMed

The quasiparticle density of states (DOS) of superconductors can be obtained from tunneling spectroscopy. When the normal-state differential conductance varies on the voltage scale comparable to that of strong-coupling effects, the standard normalization rule to extract the DOS is invalid, and the DOS is related to the measured data via an integral equation. These effects are exemplified by studying the geometry effect on the DOS for simple BCS superconductors. We apply these considerations to UPd2Al3 tunnel data where the apparent strong-coupling effects, previously deduced by use of the normalization rule, can be quantitatively attributed to convolution effects. PMID:18233552

Geerk, J; V Löhneysen, H

2007-12-19

438

Effects of Security actions  

NASA Astrophysics Data System (ADS)

In a project funded by the Swedish Civil Contingencies Agency, the effort and work to reduce different kinds of accidents are being evaluated. The project wants to illuminate the links between actions and outcome, so we can learn from today's performance and in the future select more effective measures and overall deal with accidents more efficiently. The project ESS covers the field of frequent accidents such as sliding accidents at home, in house fires and less common accidents such as chemical and land fill accidents up to even more rare accidents such as natural accidents and hazards. In the ESS project SGI (Swedish geotechnical institute) will evaluate the work and effort concerning various natural hazards limited to landslides, erosion and flooding. The aim is to investigate how municipalities handle, especially prevention, of such natural disasters today. The project includes several aspects such as: • which are the driving forces for risk analysis in a municipality • do one use risk mapping (and what type) in municipal risk analysis • which aspects are most important when selecting preventive measures • in which way do one learn from past accidents • and from previous accidents elsewhere, by for example use existing databases • etc There are many aspects that play a role in a well-functioning safety promotion work. The overall goal is to examine present work and activities, highlight what is well functioning and identify weak points. The aim is to find out where more resources are needed and give suggestions for a more efficient security work. This includes identification of the most efficient "tools" in use or needed. Such tools can be education, directives, funding, more easily available maps and information regarding previous accidents and preventive measures etc. The project will result in recommendations for more effective ways to deal with landslides, erosion and flooding. Since different kinds of problems can occur depending on level of authority the investigation of the security work will be done with authorities on both regional and local scale. At the moment the investigation process are in progress and preliminary results will be presented.

Bergman, Ramona; Andersson-Sköld, Yvonne; Nyberg, Lars; Johansson, Magnus

2010-05-01

439

Effect sizes in memory research.  

PubMed

Effect sizes are omitted from many research articles and are rarely discussed. To help researchers evaluate effect sizes we collected values for the more commonly reported effect size measures (partial eta squared and d) from papers reporting memory research published in 2010. Cohen's small, medium, and large generic guideline values for d mapped neatly onto the observed distributions, but his values for partial eta squared were considerably lower than those observed in current memory research. We recommend interpreting effect sizes in the context of either domain-specific guideline values agreed for an area of research or the distribution of effect size estimates from published research in the domain. We provide cumulative frequency tables for both partial eta squared and d enabling authors to report and consider not only the absolute size of observed effects but also the percentage of reported effects that are larger or smaller than those observed. PMID:23350788

Morris, Peter E; Fritz, Catherine O

2013-01-25

440

Public Opinion on Mass Media Effects: Perceived Societal Effects and Perceived Personal Effects.  

ERIC Educational Resources Information Center

|The questionnaire in a study of perceived mass media effects included nine statements about the possible negative effects of the mass media, to which respondents could agree, disagree, or indicate "no opinion," and an open-ended question that asked the subjects what effects the mass media had on them personally. Most of the 340 respondents showed…

Tiedge, James T.

441

Melatonin Anticancer Effects: Review  

PubMed Central

Melatonin (N-acetyl-5-methoxytryptamine, MLT), the main hormone produced by the pineal gland, not only regulates circadian rhythm, but also has antioxidant, anti-ageing and immunomodulatory properties. MLT plays an important role in blood composition, medullary dynamics, platelet genesis, vessel endothelia, and in platelet aggregation, leukocyte formula regulation and hemoglobin synthesis. Its significant atoxic, apoptotic, oncostatic, angiogenetic, differentiating and antiproliferative properties against all solid and liquid tumors have also been documented. Thanks, in fact, to its considerable functional versatility, MLT can exert both direct and indirect anticancer effects in factorial synergy with other differentiating, antiproliferative, immunomodulating and trophic molecules that form part of the anticancer treatment formulated by Luigi Di Bella (Di Bella Method, DBM: somatostatin, retinoids, ascorbic acid, vitamin D3, prolactin inhibitors, chondroitin-sulfate). The interaction between MLT and the DBM molecules counters the multiple processes that characterize the neoplastic phenotype (induction, promotion, progression and/or dissemination, tumoral mutation). All these particular characteristics suggest the use of MLT in oncological diseases.

Di Bella, Giuseppe; Mascia, Fabrizio; Gualano, Luciano; Di Bella, Luigi

2013-01-01

442

Melatonin anticancer effects: review.  

PubMed

Melatonin (N-acetyl-5-methoxytryptamine, MLT), the main hormone produced by the pineal gland, not only regulates circadian rhythm, but also has antioxidant, anti-ageing and immunomodulatory properties. MLT plays an important role in blood composition, medullary dynamics, platelet genesis, vessel endothelia, and in platelet aggregation, leukocyte formula regulation and hemoglobin synthesis. Its significant atoxic, apoptotic, oncostatic, angiogenetic, differentiating and antiproliferative properties against all solid and liquid tumors have also been documented. Thanks, in fact, to its considerable functional versatility, MLT can exert both direct and indirect anticancer effects in factorial synergy with other differentiating, antiproliferative, immunomodulating and trophic molecules that form part of the anticancer treatment formulated by Luigi Di Bella (Di Bella Method, DBM: somatostatin, retinoids, ascorbic acid, vitamin D3, prolactin inhibitors, chondroitin-sulfate). The interaction between MLT and the DBM molecules counters the multiple processes that characterize the neoplastic phenotype (induction, promotion, progression and/or dissemination, tumoral mutation). All these particular characteristics suggest the use of MLT in oncological diseases. PMID:23348932

Di Bella, Giuseppe; Mascia, Fabrizio; Gualano, Luciano; Di Bella, Luigi

2013-01-24

443

The Second Mössbauer Effect  

NASA Astrophysics Data System (ADS)

"The Second Mössbauer Effect" was the headline of the "Spiegel" (a German weekly journal like the "Times") from May 13, 1964 for announcing the foundation of the "Physik-Department" at the Technische Hochschule München (THM), as it was still called at this time. Maier-Leibnitz was irritated by this headline because the article did not mention at all his contribution to the consolidation of the structure of the three physics institutes (Experimental, Technical, and Theoretical Physics) in the beginning of the sixties. Already in the late fifties ML's Institute for Technical Physics was overloaded with students working on their diploma or doctoral theses, because research in the new field of applied nuclear physics was very attractive and ML had for each student who applied an interesting research project. In the average, ML had to supervise between 150-200 diploma students, an impossible task. So, young postdoctoral students had to help him out by taking over the duties of professors. In a letter to the Bavarian Ministry of Education and Arts in 1957 he complained: "The directors of the institutes are hopelessly surcharged and the institutes are overcrowded, the resources for research projects are totally insufficient and lots of time and energy is wasted for finding additional resources."

Kienle, Paul

444

Quantum Wipe Effect  

NASA Astrophysics Data System (ADS)

We consider a model of a spin system under the influence of decoherence such that a system coupled with a dissipating environmental system consisting of either spins or bosonic modes. The dissipation of an environment is governed by a certain probability with which an environmental system localized around a principal system dissipates into a larger bath and a thermal environmental system instead migrates into the place. A certain threshold on the probability is found in the growth of decoherence in a principal system. A larger as well as a smaller dissipation probability than the threshold results in smaller decoherence. This finding is utilized to elucidate a spin relaxation theory of a magnetic resonance spectrometer. In particular, a seamless description of transverse relaxation and motional narrowing is possible. We also numerically evaluate the dynamics of coherence useful for quantum information processing. The bang-bang control and anti-Zeno effect in entanglement and the Oppenheim-Horodecki nonclassical correlation are investigated in the model of spin-boson coupling.

Saitoh, Akira; Rahimi, Robabeh; Nakahara, Mikio

2010-11-01

445

Effectively Rebutting Climate Misinformation  

NASA Astrophysics Data System (ADS)

Climate science faces one of the best funded misinformation campaigns in history. The challenge for climate communicators is that misinformation is extremely difficult to dislodge, even after people understand that it's incorrect. Understanding how the human brain processes information is crucial to successful rebuttal. To avoid the danger of reinforcing misinformation (known as the 'backfire effect'), emphasis should be on positive facts, not the myth. Another key to dislodging myths is replacing them with an alternate narrative. In order to provide a narrative about arguments that misrepresent climate science, a broader understanding of how these arguments mislead is required. Movements that deny a scientific consensus have 5 characteristics in common and these also apply to climate denial. The arguments against the scientific consensus involve conspiracy theories, fake experts, cherry picking, logical fallacies and misrepresentation or impossible expectations. Learning to identify these rhetorical techniques is an important tool in the climate communication toolbox. I discuss examples of misrepresentations of climate science and the rhetorical techniques employed. I demonstrate how to respond to these arguments by explaining the facts of climate science while in the process, providing an alternate narrative.

Cook, J.

2011-12-01

446

Unruh effect and holography  

NASA Astrophysics Data System (ADS)

We study the Unruh effect on the dynamics of quarks and mesons in the context of AdS5/CFT4 correspondence. We adopt an AdS5 metric with the boundary Rindler horizon extending into a bulk Rindler-like horizon, which yields the thermodynamics with Unruh temperature verified by computing the boundary stress tensor. We then embed in it a probe fundamental string and a D7 brane in such a way that they become the dual of an accelerated quark and a meson in Minkowski space, respectively. Using the standard procedure of holographic renormalization, we calculate the chiral condensate, and also the spectral functions for both the accelerated quark and meson. Especially, we extract the corresponding strength of random force of the Langevin dynamics and observe that it can characterize the phase transition of meson melting. This result raises an issue toward a formulation of complementarity principle for the Rindler horizon. We find most of the dynamical features are qualitatively similar to the ones in the thermal bath dual to the AdS black hole background, though they could be quite different quantitatively.

Hirayama, Takayuki; Kao, Pei-Wen; Kawamoto, Shoichi; Lin, Feng-Li

2011-03-01

447

Funnelling Effect in Networks  

NASA Astrophysics Data System (ADS)

Funnelling effect, in the context of searching on networks, precisely indicates that the search takes place through a few specific nodes. We define the funnelling capacity f of a node as the fraction of successful dynamic paths through it with a fixed target. The distribution D(f) of the fraction of nodes with funnelling capacity f shows a power law behaviour in random networks (with power law or stretched exponential degree distribution) for a considerable range of values of the parameters defining the networks. Specifically we study in detail D 1 = D(f = 1), which is the quantity signifying the presence of nodes through which all the dynamical paths pass through. In scale free networks with degree distribution P(k) ? k - ? , D 1 increases linearly with ? initially and then attains a constant value. It shows a power law behaviour, D_1 ? N^{-?}, with the number of nodes N where ? is weakly dependent on ? for ?> 2.2. The latter variation is also independent of the number of searches. On stretched exponential networks with P(k) ? exp{(-k^?)}, ? is strongly dependent on ?. The funnelling distribution for a model social network, where the question of funnelling is most relevant, is also investigated.

Sen, Parongama

448

Pulmonary effects of nebivolol.  

PubMed

The pharmacological control of arterial hypertension is a very frequent issue in clinical practice and some critical aspects can arise in particular circumstances and with particular molecules. In the case of hypertensive subjects with respiratory comorbidities, when first introduced, these beta-adrenergic receptor antagonists were described as affecting airway patency as a result of their antagonism against beta(2)-adrenergic receptors within airway muscles. New molecules with a better respiratory tolerability were subsequently designed in order to overcome the narrow therapeutic window of first-generation beta-adrenergic receptor antagonists. Nebivolol is a third-generation beta-adrenergic receptor antagonist with high beta(1)-selective adrenergic receptor antagonism and vasodilating properties that induces a substantial decrease of arterial pressure in hypertensive subjects while preserving their left ventricular function. Respiratory effects of nebivolol have been investigated in animal models, in healthy volunteers and in clinical trials carried out on patients suffering from bronchial asthma and chronic obstructive pulmonary disease (COPD). In contrast to older compounds, nebivolol, which modulates the endogenous production of nitric oxide and affects oxidative cascade, proved clinically well tolerated in terms of respiratory outcomes in this type of subject. Moreover, due to the substantial dissociation between its cardiac and pulmonary activity, nebivolol confirmed a very good safety profile when regularly administered to hypertensive subjects with obstructive respiratory comorbidities. PMID:19638367

Dal Negro, Roberto

2009-08-01

449

Beyond the sulfur effect  

SciTech Connect

The addition of reactive elements (REs) is known to increase the adherence of Al{sub 2}O{sub 3} scales and the underlying alloys. A widely accepted mechanism is that the REs getter the sulfur impurity in the alloy, thus preventing it from segregating to the scale-alloy interface to weaken the interfacial bonding. This paper provides evidence showing that not all S-free interfaces are strong. Although eliminating the sulfur in the alloy can greatly improve scale adhesion, the presence of RE clearly has additional beneficial effects that make the scale-alloy interface even stronger. Fe{sub 3}Al-base alloys, with or without Zr additions or a desulfurization H{sub 2}-anneal were oxidized at 1000 C in O{sub 2}. The amount of sulfur at the Al{sub 2}O{sub 3}-alloy interface was studied after the scales were removed by scratching with a diamond stylus in ultra-high vacuum using Auger spectroscopy. The interface composition was related to the spallation resistance of the scale.

Hou, P.Y. [Lawrence Berkeley National Lab., CA (United States). Materials Science Div.

1999-10-01

450

(Limiting the greenhouse effect)  

SciTech Connect

Traveler attended the Dahlem Research Conference organized by the Freien Universitat, Berlin. The subject of the conference was Limiting the Greenhouse Effect: Options for Controlling Atmospheric CO{sub 2} Accumulation. Like all Dahlem workshops, this was a meeting of scientific experts, although the disciplines represented were broader than usual, ranging across anthropology, economics, international relations, forestry, engineering, and atmospheric chemistry. Participation by scientists from developing countries was limited. The conference was divided into four multidisciplinary working groups. Traveler acted as moderator for Group 3 which examined the question What knowledge is required to tackle the principal social and institutional barriers to reducing CO{sub 2} emissions'' The working rapporteur was Jesse Ausubel of Rockefeller University. Other working groups examined the economic costs, benefits, and technical feasibility of options to reduce emissions per unit of energy service; the options for reducing energy use per unit of GNP; and the significant of linkage between strategies to reduce CO{sub 2} emissions and other goals. Draft reports of the working groups are appended. Overall, the conference identified a number of important research needs in all four areas. It may prove particularly important in bringing the social and institutional research needs relevant to climate change closer to the forefront of the scientific and policy communities than hitherto.

Rayner, S.

1991-01-07

451

Matrix effective theories of the fractional quantum Hall effect  

Microsoft Academic Search

The present understanding of nonperturbative ground states in the fractional quantum Hall effect is based on effective theories of the Jain 'composite fermion' excitations. We review the approach based on matrix variables, i.e. D0 branes, originally introduced by Susskind and Polychronakos. We show that the Maxwell-Chern-Simons matrix gauge theory provides a matrix generalization of the quantum Hall effect, where the

Andrea Cappelli; Ivan D. Rodriguez

2009-01-01

452

The effect of dipolar interaction on the magnetic isotope effect  

NASA Astrophysics Data System (ADS)

A multi-channel kinetic description is used to study the magnetic isotope effect (MIE) in zero magnetic field. The maximal isotope effect is equal to the number of channels, two for the hyperfine interaction but four for the electron spin dipole-dipole interaction of the intermediate radical pair. Quantum mechanical calculations agree with these conclusion and show that large MIE may be obtained even in the presence of a strong exchange interaction. The observed magnesium isotope effect on the rate of enzymatic synthesis of adenosine triphosphate (ATP) is approximately 3 implying that the dipolar interaction is responsible for the effect. Our calculations provide support for the proposed mechanism.

Pedersen, J. Boiden; Mojaza, Matin; Lukzen, Nikita N.

2010-08-01

453

Models for effective prevention.  

PubMed

The social influence models do provide some optimism for primary prevention efforts. Prevention programs appear most effective when 1) the target behavior of the intervention has received increasing societal disapproval (such as cigarette smoking), 2) multiple years of behavioral health education are planned, and 3) community-wide involvement or mass media complement a school-based peer-led program (45,46). Short-term programs and those involving alcohol use have had less favorable outcomes. Future research in primary prevention should address concerns of high-risk groups and high-risk countries, such as lower income populations in the United States or countries that have large adolescent homeless populations. The utilization of adolescent leaders for program dissemination might be particularly critical in these settings. A second major and global concern should focus upon alcohol use and alcohol-related problems. In many communities adolescent alcohol use is normative and even adult supported. Thus, young people are getting quite inconsistent messages on alcohol from their schools, from TV, from peers, and from parents. This inconsistency may translate into many tragic and avoidable deaths for young people. Clearly, in the area of alcohol-related problems, community-wide involvement may be necessary. A third direction for prevention research should involve issues of norms, access, and enforcement including policy interventions, such as involve the availability of cigarette vending machines or the ease of under-age buying or levels of taxation. These methods affect adolescents more acutely since their financial resources, for the most part, are more limited. These policy level methods also signify to adolescents what adults consider appropriate.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1390786

Perry, C L; Kelder, S H

1992-07-01

454

Neuroendocrine effects of light  

NASA Astrophysics Data System (ADS)

The light/dark cycle to which animals, and possibly humans, are exposed has a major impact on their physiology. The mechanisms whereby specific tissues respond to the light/dark cycle involve the pineal hormone melatonin. The pineal gland, an end organ of the visual system in mammals, produces the hormone melatonin only at night, at which time it is released into the blood. The duration of elevated nightly melatonin provides every tissue with information about the time of day and time of year (in animals that are kept under naturally changing photoperiods). Besides its release in a circadian mode, melatonin is also discharged in a pulsatile manner; the physiological significance, if any, of pulsatile melatonin release remains unknown. The exposure of animals including man to light at night rapidly depresses pineal melatonin synthesis and, therefore, blood melatonin levels drop precipitously. The brightness of light at night required to depress melatonin production is highly species specific. In general, the pineal gland of nocturnally active mammals, which possess rod-dominated retinas, is more sensitive to inhibition by light than is the pineal gland of diurnally active animals (with cone-dominated retinas). Because of the ability of the light/dark cycle to determine melatonin production, the photoperiod is capable of influencing the function of a variety of endocrine and non-endocrine organs. Indeed, melatonin is a ubiquitously acting pineal hormone with its effects on the neuroendocrine system having been most thoroughly investigated. Thus, in nonhuman photoperiodic mammals melatonin regulates seasonal reproduction; in humans also, the indole has been implicated in the control of reproductive physiology.

Reiter, Russel J.

1991-09-01

455

Effective Sizes for Subdivided Populations  

PubMed Central

Many derivations of effective population sizes have been suggested in the literature; however, few account for the breeding structure and none can readily be expanded to subdivided populations. Breeding structures influence gene correlations through their effects on the number of breeding individuals of each sex, the mean number of progeny per female, and the variance in the number of progeny produced by males and females. Additionally, hierarchical structuring in a population is determined by the number of breeding groups and the migration rates of males and females among such groups. This study derives analytical solutions for effective sizes that can be applied to subdivided populations. Parameters that encapsulate breeding structure and subdivision are utilized to derive the traditional inbreeding and variance effective sizes. Also, it is shown that effective sizes can be determined for any hierarchical level of population structure for which gene correlations can accrue. Derivations of effective sizes for the accumulation of gene correlations within breeding groups (coancestral effective size) and among breeding groups (intergroup effective size) are given. The results converge to traditional, single population measures when similar assumptions are applied. In particular, inbreeding and intergroup effective sizes are shown to be special cases of the coancestral effective size, and intergroup and variance effective sizes will be equal if the population census remains constant. Instantaneous solutions for effective sizes, at any time after gene correlation begins to accrue, are given in terms of traditional F statistics or transition equations. All effective sizes are shown to converge upon a common asymptotic value when breeding tactics and migration rates are constant. The asymptotic effective size can be expressed in terms of the fixation indices and the number of breeding groups; however, the rate of approach to the asymptote is dependent upon dispersal rates. For accurate assessment of effective sizes, initial, instantaneous or asymptotic, the expressions must be applied at the lowest levels at which migration among breeding groups is nonrandom. Thus, the expressions may be applicable to lineages within socially structured populations, fragmented populations (if random exchange of genes prevails within each population), or combinations of intra- and interpopulation discontinuities of gene flow. Failure to recognize internal structures of populations may lead to considerable overestimates of inbreeding effective size, while usually underestimating variance effective size.

Chesser, R. K.; Rhodes-Jr., O. E.; Sugg, D. W.; Schnabel, A.

1993-01-01

456

Antigonococcal effects of vaginal tampons.  

PubMed Central

Different brands of vaginal tampons varied significantly (p less than 0.0001) in their anti-bacterial effects when tested with 46 strains of Neisseria gonorrhoeae. Gonococcal strains recovered from patients with disseminated infections were substantially more sensitive to the anti-bacterial effects of tampons than were strains from patients with uncomplicated genital infections. Strains from patients with pelvic inflammatory disease were moderately sensitive. Tampons showing strong in-vitro antigonococcal effects were also generally effective in vivo in eliminating gonococcal infections from subcutaneous chambers in mice. Extracts of the Rely tampon showed no in-vitro antigonococcal effect, however, but did induce antibacterial activity when injected into subcutaneous chambers in mice. These results emphasise the importance of both in-vitro as well as in-vivo testing of tampon materials to elucidate more fully the nature of their antibacterial effects and their potential for affecting vaginal pathogens and disease processes.

Arko, R J; Wong, K H; Smith, S J; Finley-Price, K G

1983-01-01

457

Fatigue: environment and temperature effects  

SciTech Connect

An overview of temperature and environmental effects of fatigue is provided and room temperature environmental effects are examined, taking into account corrosion fatigue crack propagation, surface reactions and fatigue crack growth, and the determination of prefracture damage and failure prediction in corrosion-fatigued Al-2024-T4 by X-ray diffraction methods. Room temperature environmental effects are considered along with materials, and design engineering applications. High temperature and environmental effects are explored, giving attention to the effect of microstructure on the fatigue behavior of Ni base superalloys, creep crack growth, the temperature dependent deformation mechanisms of alloy 718 in low cycle fatigue, deformation induced microstructural changes in austenitic stainless steels, fatigue and fracture resistance of stainless steel weld deposits after elevated temperature irradiation, high-temperature static fatigue in ceramics, and environment, frequency, and temperature effects on fatigue in engineering plastics.

Burke, J.J.; Weiss, V.

1983-01-01

458

Effects of sea spray geoengineering  

NASA Astrophysics Data System (ADS)

Anthropogenic climate warming is leading to consideration of options for geoengineering to offset rising carbon dioxide levels. One potential technique involves injecting artificial sea spray into the atmosphere. The sea salt particles would affect Earth's radiation budget directly, by scattering incoming solar radiation, and indirectly, by acting as cloud condensation nuclei, which could lead to whiter clouds that reflect more radiation. However, the potential effects of this method, especially the direct effects, are not fully known. Partanen et al. studied the effects of artificial sea spray using climate model simulations. They found that outside of the most heavily clouded regions the direct effect of scattering of radiation was an important part of the total effect. They also examined the effect of particle size and found that decreasing the size of injected particles could improve the efficiency of the geoengineering technique.

Balcerak, Ernie

2012-03-01

459

Reverse coffee-ring effect  

NASA Astrophysics Data System (ADS)

When a coffee drop dries on a solid surface, it commonly leaves a ring-like deposit along the edge, known as the coffee-ring effect. We present a reverse motion of particles in drying droplets, opposite to the coffee-ring effect. We reveal that the particle motion, initially toward the edge by the typical coffee-ring effect, is reversed to the droplet center owing to the capillary interaction generated by the droplet surface. The reverse coffee-ring effect always occurs whenever the capillary interaction prevails over the net outward force by the coffee- ring effect. The interaction predicts an inverse power-law time growth of moving distance from the edge, depending mostly on particle size and contact angle. The reverse coffee-ring effect may contribute to multiple ring formation by sweeping particles toward the center. We prove the mechanism with real-time optical, confocal, and X-ray microscopic observations of colloidal fluids.

Mook Weon, Byung; Xu, Lei; Je, Jung Ho; Hwu, Yeukuang; Margaritondo, Giorgio; Weitz, David A.

2009-03-01

460

Effective medium theory for thermoelectrics  

NASA Astrophysics Data System (ADS)

We report on the application of effective medium theory to binary compound thermoelectric materials. We find a range of parameters for the conductivity and thermopower of the constituent elements such that the compound has an enhanced power factor. The results of effective medium theory are compared to full numerical simulations of an ensemble of disordered systems, and good qualitative agreement is found between the two calculations. The effect of various tailored geometries are explored in the direct numerical solution of the compound thermoelectrics.

Haney, Paul

2011-03-01

461

Peer effects in Austrian schools  

Microsoft Academic Search

This study deals with educational production in Austria and is focused on the impact of schoolmates on students’ academic\\u000a outcomes. We use PISA 2000 and 2003 data to estimate peer effects for 15 and 16 year old students. School fixed effects are\\u000a employed to address the potential self-selection of students into schools and peer groups. The estimations show significant\\u000a positive effects

Nicole Schneeweis; Rudolf Winter-Ebmer

2007-01-01

462

Effectiveness of multiple decoupling capacitors  

Microsoft Academic Search

The effectiveness of using the parallel combination of large-value and small-value capacitors to increase the frequency coverage of either one and overcome the effect of lead inductance is examined. Computed and experimental results are given that show this scheme is not significantly effective. The improvement at high frequencies is at most 6 dB over the use of only the large-value

Clayton R. Paul

1992-01-01

463

Effects of harmonics on equipment  

SciTech Connect

The purpose of this paper is to summarize the state-of-knowledge of the effects of power system harmonics on equipment. The general mechanisms presented are thermal overloading, disruption, and dielectric stressing. Quantitative effects are presented or referenced whenever possible. However, many of the effects can only be qualitatively described. The equipment considered are adjustable speed drives, capacitors, circuit breakers, fuses, conductors, electronic equipment, lighting, metering, protective relays, rotating machines, telephones, and transformers.

Wagner, V.E.; Balda, J.C.; Barnes, T.M.; Emannuel, A.E.; Ferraro, R.J.; Griffith, D.C.; Hartmann, D.P.; Horton, W.F.; Jewell, W.T.; McEachern, A.; Phileggi, D.J.; Reid, W.E.

1993-04-01

464

Microstructural effects in shock ignition  

SciTech Connect

The dynamic response of explosive microstructures has been explicitly modeled, with the intention of gaining insight into initiation processes from hotspot formation to transition to detonation. In this paper, the authors focus attention upon the inert material response leading to hotspot ignition. Of interest are particle size and shape effects, constitutive effects of both binder and explosive, and their importance to hotspot formation. Effects of chemical reaction are considered elsewhere.

Conley, P.; Benson, D. [Univ. of California, San Diego, CA (United States); Howe, P.M. [Los Alamos National Lab., NM (United States)

1998-07-01

465

GENETIC EFFECTS OF ELECTROMAGNETIC WAVES  

Microsoft Academic Search

The genetic effects of electromagnetic waves can be detected by different test-systems. The mutagenic effect of ionizing radiation\\u000a can be developed on the levels of DNA and\\/or chromosomes. In numerous researches efficiency of micronucleus assay, alkaline\\u000a single-cell gel electrophoresis, chromosomal aberrations test and FISH-technique and their different combinations for the\\u000a detection of ionizing radiation-induced genotoxic effects are discussed. Also some

Rouben Aroutiounian; Galina Hovhannisyan; Gennady Gasparian

466

Electro-magneto-optical Effects  

Microsoft Academic Search

Electro-magneto-optical effects in stationary materials are observed when the materials are placed in strong, static electric or magnetic fields and an electro- magnetic wave (light) traverses the medium. The Faraday effect is an example of the class of phenomena we have in mind. Clearly, the existence of electro- magneto-optical effects in material media is direct evidence that the equations for

R. A. Toupin; R. S. Rivlin

1961-01-01

467

Genetic Effects of Electromagnetic Waves  

NASA Astrophysics Data System (ADS)

The genetic effects of electromagnetic waves can be detected by different test-systems. The mutagenic effect of ionizing radiation can be developed on the levels of DNA and/or chromosomes. In numerous researches efficiency of micronucleus assay, alkaline single-cell gel electrophoresis, chromosomal aberrations test and FISH-technique and their different combinations for the detection of ionizing radiation-induced genotoxic effects are discussed. Also some molecular-biological approaches developed in the last years are presented.

Aroutiounian, Rouben; Hovhannisyan, Galina; Gasparian, Gennady

468

Magnetocaloric effect in manganites  

NASA Astrophysics Data System (ADS)

The magnetocaloric effect (MCE) in La1 - x Sr x MnO3, Sm0.55Sr0.45MnO3, and PrBaMn2O6 compounds is studied. The maximum values of MCE (? T max) determined by a direct method in the second and third compositions and in La0.9Sr0.1MnO3 are found to be much lower than those calculated from the change of the magnetic part of entropy in the Curie temperature ( T C) and the Néel temperature ( T N) range. The negative contribution of the antiferromagnetic (AFM) part of a sample in the La1 - x Sr x MnO3 system at 0.1 ? x ? 0.3 decreases ? T max and changes the ? T( T) curve shape, shifting its maximum 20-40 K above T C. Lower values of ? T max are detected in the range T C = 130-142 K in polycrystalline and single-crystal Sm0.55Sr0.45MnO3 samples cooled in air. If such samples were cooled in an oxygen atmosphere (which restores broken Mn-O-Mn bonds and, thus, increases the volume of CE-type AFM clusters), the maximum in the temperature dependence of MCE is located at T N (243 K) for CE-type AFM clusters. A magnetic field applied to a sample during the MCE measurements transforms these clusters into a ferromagnetic (FM) state, and both types of clusters decompose at T = T N. The PrBaMn2O6 composition undergoes an AFM-FM transition at 231 K, and the temperature dependence of its MCE has a sharp minimum at T = 234 K, where MCE is negative, and a broad maximum covering T C. The absolute values of MCE at both extrema are several times lower than those calculated from the change in the magnetic entropy. These phenomena are explained by the presence of a magnetically heterogeneous FM-AFM state in these manganites.

Koroleva, L. I.; Zashchirinskii, D. M.; Morozov, A. S.; Szymczak, R.

2012-10-01

469

Magnetocaloric effect in manganites  

SciTech Connect

The magnetocaloric effect (MCE) in La{sub 1-x}Sr{sub x}MnO{sub 3}, Sm{sub 0.55}Sr{sub 0.45}MnO{sub 3}, and PrBaMn{sub 2}O{sub 6} compounds is studied. The maximum values of MCE ({Delta}T{sub max}) determined by a direct method in the second and third compositions and in La{sub 0.9}Sr{sub 0.1}MnO{sub 3} are found to be much lower than those calculated from the change of the magnetic part of entropy in the Curie temperature (T{sub C}) and the Neel temperature (T{sub N}) range. The negative contribution of the antiferromagnetic (AFM) part of a sample in the La{sub 1-x}Sr{sub x}MnO{sub 3} system at 0.1 {<=} x {<=} 0.3 decreases {Delta}T{sub max} and changes the {Delta}T(T) curve shape, shifting its maximum 20-40 K above T{sub C}. Lower values of {Delta}T{sub max} are detected in the range T{sub C} = 130-142 K in polycrystalline and single-crystal Sm{sub 0.55}Sr{sub 0.45}MnO{sub 3} samples cooled in air. If such samples were cooled in an oxygen atmosphere (which restores broken Mn-O-Mn bonds and, thus, increases the volume of CE-type AFM clusters), the maximum in the temperature dependence of MCE is located at T{sub N} (243 K) for CE-type AFM clusters. A magnetic field applied to a sample during the MCE measurements transforms these clusters into a ferromagnetic (FM) state, and both types of clusters decompose at T = T{sub N}. The PrBaMn{sub 2}O{sub 6} composition undergoes an AFM-FM transition at 231 K, and the temperature dependence of its MCE has a sharp minimum at T = 234 K, where MCE is negative, and a broad maximum covering T{sub C}. The absolute values of MCE at both extrema are several times lower than those calculated from the change in the magnetic entropy. These phenomena are explained by the presence of a magnetically heterogeneous FM-AFM state in these manganites.

Koroleva, L. I., E-mail: koroleva@phys.msu.ru; Zashchirinskii, D. M.; Morozov, A. S. [Moscow State University (Russian Federation); Szymczak, R. [Polish Academy of Sciences, Institute of Physics (Poland)

2012-10-15

470

Oscillating magnetocaloric effect on graphenes  

NASA Astrophysics Data System (ADS)

The magnetocaloric effect of non-relativistic diamagnetic materials presents an oscillatory character due to the crossing of the Landau levels with the Fermi energy. This effect occurs at low temperature (ca 1 K) and high magnetic field (ca 10 T). Considering the relativistic properties of graphenes, a 2D massless diamagnetic material, these oscillations could be preserved and the effect occurs in a much higher temperature (ca 100 K), due to the huge Fermi velocity (106 m/s). In addition, the magnetocaloric effect can be tuned as either inverse or normal, by changing the magnetic field change in ca 3.4 T.

Reis, M. S.

2012-11-01

471

Density-dependent effective interactions  

SciTech Connect

An effective two nucleon interaction is defined by an optimal fit to select on- and half-off-of-the-energy shell {ital t} and {ital g} matrices determined by solutions of the Lippmann-Schwinger and Brueckner-Bethe-Goldstone equations with the Paris two nucleon interaction as input. As such, it reproduces the interaction on which it is based better than other commonly used, density dependent effective interactions. This new (medium modified) effective interaction, when folded with appropriate density matrices, has been used to define proton-{sup 12}C and proton-{sup 16}O optical potentials. With them elastic scattering data are well fit and the medium effects identifiable.

Dortmans, P.J.; Amos, K. [School of Physics, University of Melbourne, Parkville, 3052 Victoria (Australia)

1994-03-01

472

Effect of geometry on the effective moisture transfer diffusion coefficient  

Microsoft Academic Search

The effective moisture transfer diffusion coefficient (Deff) of ready-to-eat breakfast cereals (RTE) is determined either from an individual particle or a bulk of material in the literature. The Deff is assumed to be the same in both cases which can be dependent on the material thickness. In this study, the effect of bed depth of a bulk of two types

M. Ahmet Tütüncü; T. P. Labuza

1996-01-01

473

Radiation effects on livestock: physiological effects, dose response  

Microsoft Academic Search

Farm livestock show no measurable effects from being exposed to ionizing radiation unless the level is greatly in excess of the natural background radiation. Possible sources of ionizing radiation which might affect livestock or contribute to radioactivity in the food chain to humans are reactor accidents, fuel reprocessing plant accidents and thermonuclear explosions. Most data on ionizing radiation effects on

Bell

1985-01-01

474

WHAT LEVEL OF EFFECT IS A NO OBSERVED EFFECT?  

Microsoft Academic Search

The no observed effect concentration (NOEC) is currently a major summary statistic in ecotoxicity testing. Its use is heavily criticized, partly because it is a poor estimator of ''safe'' chemical concentrations. In this short communication, we review the limited information available on the percentage effect that corresponds with the NOEC, a value designated the ECNOEC, and calculate ECNOEC values for

Mark Crane; Michael C. Newman

2000-01-01

475

Stimulant Treatment over Five Years: Adherence, Effectiveness, and Adverse Effects.  

ERIC Educational Resources Information Center

|Objective: To evaluate the impact of adherence and medication status on effectiveness and adverse effects of stimulant use in children with attention-deficit/hyperactivity disorder (ADHD) over 5 years. Method: Seventy-nine of 91 participants in a 12-month randomized controlled trial of methylphenidate and parent groups enrolled in a follow-up…

Charach, Alice; Ickowicz, Abel; Schachar, Russell

2004-01-01

476

Dispersant effectiveness: Studies into the causes of effectiveness variations  

Microsoft Academic Search

Effectiveness, a key issue of using dispersants, is affected by many interrelated factors. The principal factors involved are the oil composition, dispersant formulation, sea surface turbulence and dispersant quantity. Oil composition is a very strong determinant. Current dispersant formulation effectiveness correlates strongly with the amount of saturate component in the oil. The other components of the oil, the asphaltenes, resins

M. F. Fingas; D. Kyle; E. Tennyson

1995-01-01

477

Recent Advances in Anomalous Hall Effect and Spin Hall Effect  

Microsoft Academic Search

Recent advances in the studies of anomalous Hall effect (AHE) and the spin Hall effect (SHE) are described with the emphasis on the (i) universal scaling of AHE, (ii) the metallic SHE, and (iii) the noncentro-symmetric superconductors as an analogue of quantum spin Hall system.

N. Nagaosa

2009-01-01

478

Effective radiance temperature: Concept, measurement and effective wavelength  

NASA Astrophysics Data System (ADS)

Radiation thermometers measure the effective spectral radiation from a non-blackbody. Thus, the present study re-explains radiance thermometry using effective radiance temperature (ERT) suitable for an arbitrary temperature measurement in which ambient radiation exists. The theory of effective wavelength is adopted to elucidate the relationship between the "subjective" integral effective radiance temperature (the reading of an actual band-pass radiation thermometer) and the "objective" ERT by means of the integral intermediate value theorem, i.e., the value of integral effective radiance temperature measured by a thermometer is equal to ERT at the effective wavelength of the measurement. A unidirectional scanning approach for calculating the effective wavelength, with no iterative algorithm and suitable for existing multi-values, is introduced. The existence, non-monodromy, and geometric and physical meanings of the effective wavelength for an ERT measurement are discussed. ERT feature, which has a marked difference from that of classical radiance temperature, is expounded. ERT is more consistent with the nature of the apparent temperature and is more relevant in the discussion of the thermometric feature of a thermometer. Radiance temperature can be considered as a special case of ERT.

Yuan, Z.

2013-09-01

479

Hemodynamic Effects of Antiarrhythmic Compounds: Intrinsic Effects and Autonomic Modulation  

Microsoft Academic Search

Besides their proarrhythmic side-effects, most antiarrhythmic drugs exert varying degrees of depressant action on hemodynamics, which may limit their utility, especially in patients with compromised left ventricular function. Antiarrhythmic drugs have not only myocardial inotropic effects but also act on the coronary and peripheral circulation and the heart rate. Thus, sophisticated and appropriate experimental conditions are necessary to define the

Hans Martin Hoffmeister; Martin E Beyer; Ludger Seipel

1997-01-01

480

The Effect of Driving Simulator Fidelity on Training Effectiveness  

Microsoft Academic Search

The degree of driving simulator fidelity certainly has some effect on its potential training effectiveness. This paper describes post -training accident analysis results for a project that has been previously presented at DSC conferences. Training involved three simulator configurations: 1) an instrumented cab with wide angle projected display; 2) a wide field of view desktop system with a three monitor

R. Wade Allen; George D. Park; Marcia L. Cook; Dary Fiorentino

2007-01-01

481

Space charge effect and mirror charge effect in photoemission spectroscopy  

SciTech Connect

We report the observation and systematic investigation of the space charge effect and mirror charge effect in photoemission spectroscopy. When pulsed light is incident on a sample, the photoemitted electrons experience energy redistribution after escaping from the surface because of the Coulomb interaction between them (space charge effect) and between photoemitted electrons and the distribution of mirror charges in the sample (mirror charge effect). These combined Coulomb interaction effects give rise to an energy shift and a broadening which can be on the order of 10 meV for a typical third-generation synchrotron light source. This value is comparable to many fundamental physical parameters actively studied by photoemission spectroscopy and should be taken seriously in interpreting photoemission data and in designing next generation experiments.

Zhou, X.J.; Wannberg, B.; Yang, W.L.; Brouet, V.; Sun, S.; Douglas, J.F.; Dessau, D.; Hussain, Z.; Shen, Z.-X.

2004-08-17

482

Exercise effects on mucosal immunity  

Microsoft Academic Search

The present review examines the effects of exercise on mucosal immunity in recreational and elite athletes and the role of mucosal immunity in respiratory illness. Habitual exercise at an intense level can cause suppression of mucosal immune parameters, while moderate exercise may have positive effects. Saliva is the most commonly used secretion for measurement of secretory antibodies in the assessment

Maree Gleeson; David B Pyne

2000-01-01

483

The elusive wishful thinking effect  

Microsoft Academic Search

We define a desirability effect as the inflation of the judged probability of desirable events or the diminution of the judged probability of undersirable events. A series of studies of this effect are reported. In the first four experiments, subjects were presented with visual stimuli (a grid matrix in two colours, or a jar containing beads in two colours), and

Maya Bar-hillel; David Budescu

1995-01-01

484

Biological Effects of Microwave Radiation  

Microsoft Academic Search

The possibility of exposure of large segments of the population to complex, multifrequency microwave radiation in the environment is now a reality. It is necessary, therefore, to determine the safe level of exposure for the general population so as to prevent any occurrence of harmful effects without unduly restricting the beneficial uses of microwaves.The biological effects generated by exposure to

Donald I. McRee

1974-01-01

485

Retrieval Effectiveness on the Web.  

ERIC Educational Resources Information Center

|Discusses the role of search engines in Web usability and analyzes and evaluates the retrieval effectiveness of various indexing and searching strategies on a new Web text collection. Highlights include preprocessing techniques that might improve retrieval effectiveness; and hyperlinks as useful sources of evidence in improving retrieval…

Savoy, Jacques; Picard, Justin

2001-01-01

486

Immediate Neurocognitive Effects of Concussion  

Microsoft Academic Search

OBJECTIVE: To prospectively measure the immediate neurocognitive effects and early course of recovery from concussion and to examine the effects of loss of consciousness (LOC) and posttraumatic amnesia (PTA) on the severity of neurocognitive impairment immediately after concussion. METHODS: A sports-related concussion research model was used to allow prospective immediate evaluation of concussion. A total of 2385 high school and

Michael McCrea; James P. Kelly; Christopher Randolph; Ron Cisler; Lisa Berger

2002-01-01

487

Surface Effect Ships for Commerce.  

National Technical Information Service (NTIS)

Ships using the surface effect principle have been suggested as a means of improving the transport of U.S. international commerce. The functional principles of the surface effect ships (SES) appear to offer an avenue for developing transoceanic vehicles p...

1966-01-01

488

Counselor Effectiveness Through Radio Communication.  

ERIC Educational Resources Information Center

|This study determined the effectiveness of the use of radio as a means of providing immediate feedback on student counselors in a practicum setting. Using a non-equivalent group experimental design, 10 experimental subjects were compared to 10 control subjects with respect to counselor effectiveness. The experimental subjects were given immediate…

Tentoni, Stuart C.

489

GENETIC EFFECTS OF SPACEFLIGHT FACTORS  

Microsoft Academic Search

With the object of investigating effects of spaceflight factors on ; heredity, Drosophila melanogaster was carried on the second, fourth, and fifth ; orbital spaceships and on Vostok-1 and Vostok-2. Four different spaceflight ; effects were investigated. Nondisjunction of chromosomes was investigated by ; exposing unfertilized white-eyed Drosophila females on Vostoks 1 and 2 and mating ; them on their

Ya. L. Glembotskii; G. P. Parfenov

1962-01-01

490

Emotional intelligence and leadership effectiveness  

Microsoft Academic Search

Purpose – This paper investigates the relationship between managerial emotional intelligence (EI) levels and a rating of leadership effectiveness (subordinate ratings). Design\\/methodology\\/approach – The study involved administering the Mayer Salovey Caruso emotional intelligence test (MSCEIT) EI test to 38 supervisors within a large manufacturing organisation. Ratings of supervisory leadership effectiveness were assessed via subordinate ratings on an attitude survey detailing

Robert Kerr; John Garvin; Norma Heaton; Emily Boyle

2006-01-01

491

Building effective service management system  

Microsoft Academic Search

Purpose – Highlight some of the Best Practices for Building Effective Service Management. Design\\/methodology\\/approach – This article describes some of the Best Practices for Effective Service Management. Case studies, success stories, and statistical examples are used to highlight some of the Best Practices. Findings – Case studies, success stories, and statistics. Originality\\/value – This session highlights some of the Best

Tajinder Pal Singh Toor

2009-01-01

492

Remote Lab Effectiveness Assessment Model  

Microsoft Academic Search

This study discusses current attempts to model the effectiveness assessment of distant labs. Distant labs, specifically remote labs (RL), are systems which are accessed through a web browser, which allow users from all over the world, anytime to perform the experiments with real devices. They increase teaching efficiency, provide time and money savings. Consequently, remote lab effectiveness influence the course

G. Tokdemir; S. Bilgen

2008-01-01

493

Effect Size in Clinical Phonology  

ERIC Educational Resources Information Center

|The purpose of this article is to motivate the use of effect size (ES) for single-subject research in clinical phonology, with an eye towards meta-analyses of treatment effects for children with phonological disorders. Standard mean difference (SMD) is introduced and illustrated as one ES well suited to the multiple baseline (MBL) design and…

Gierut, Judith A.; Morrisette, Michele L.

2011-01-01

494

Switchgrass biochar effects two aridisols  

Technology Transfer Automated Retrieval System (TEKTRAN)

The use of biochar has received growing attention with regards to improving the physico-chemical properties of highly weathered Ultisols and Oxisols, yet very little research has focused on effects in Aridisols. The objective of this study was to investigate the effect of either low or high tempera...

495

Quantum effects in channeling radiation  

Microsoft Academic Search

The quantum effects on the total radiation intensity in channeling have been considered. It is shown that the problem can be considered in the frame of the magnetic bremsstrahlung limit. In the region where quantum effects are weak, the general formulae have been obtained for quantum corrections to the total intensity of the channeling radiation. While in diamond and silicon

V. N. Baier; V. M. Katkov; V. M. Strakhovenko

1992-01-01

496

Neurophysiological effects of spinal manipulation  

Microsoft Academic Search

Background context: Despite clinical evidence for the benefits of spinal maniputation and the apparent wide usage of it, the biological mechanisms underlying the effects of spinal manipulation are not known. Although this does not negate the clinical effects of spinal manipulation, it hinders acceptance by the wider scientific and health-care communities and hinders rational strategies for improving the delivery of

Joel G Pickar

2002-01-01

497

Animation About the Greenhouse Effect  

NSDL National Science Digital Library

This is a basic animation/simulation with background information about the greenhouse effect by DAMOCLES. The animation has several layers to it that allow users to drill into more detail about the natural greenhouse effect and different aspects of it, including volcanic aerosols and human impacts from burning fossil fuels.

Damocles

498

Tranquilizer effects on conditioned suppression  

Microsoft Academic Search

The effects of chlorpromazine, meprobamate and reserpine on animal experimental conditioned suppression are reported. Over a wide dose range neither chlorpromazine nor meprobamate increased responding for positive reinforcement during a shock-paired stimulus. Reserpine given chronically did increase responding during shock-paired stimuli. The motor depressant effect of reserpine, at suppression attenuating doses, is most probably related to the response measure used

Oakley S. Ray

1964-01-01

499

Correlation effects and bound states  

SciTech Connect

Bound states in a simple quark model that are due to correlation effects are analyzed. The confining properties of this model in meson (quark-antiquark and diquark) channels manifest themselves at any quark momenta, and an extra potential field may only enhance the confining effect.

Zinovjev, G. M. [National Academy of Sciences of Ukraine, Bogolyubov Institute for Theoretical Physics (Ukraine); Molodtsov, S. V., E-mail: molodtsov@itep.ru [Joint Institute for Nuclear Research (Russian Federation)

2012-11-15

500

Neighbourhood effects and endogeneity issues  

Microsoft Academic Search

A recent body of research suggests that the spatial structure of cities might influence the socioeconomic characteristics and outcomes of their residents. In particular, the literature on neighbourhood effects emphasizes the potential influence of the socioeconomic composition of neighbourhoods in shaping individual’s behaviours and outcomes, through social networks, peer influences or socialization effects. However, empirical work still has not reached

Claire DUJARDIN; Dominique PEETERS; Isabelle THOMAS

2009-01-01